RMZ – MATERIALI IN GEOOKOLJE

IVTable of Contents – KazaloProfessional papers – Strokovni člankiŽelezniška livarna v Šiški 443Railway-foundry in ŠiškaLajovic, A.Event notes – NoviceDruštvo alumnov diplomantov Oddelka za materiale in metalurgijo 469Medved, j., Rosina, a., Vončina, m.Author`s Index, Vol. 59, No. 4 471Author`s Index, Vol. 59 472Contents, Volume 59, 2012/1, 2/3, 4 475Instructions to Authors 479Template 487RMZ-M&G 2012, 59

RMZ – Materials and Geoenvironment, Vol. 59, No. 4, pp. 331–346, 2012331Calculation of stress-strain dependence from tensile tests athigh temperatures using final shapes of specimen’s contoursDoločitev odvisnosti napetost – deformacija z nateznimi preizkusiv vročem in na osnovi končnih oblik nateznih palicGoran Kugler 1 , Milan Terčelj 1 , Iztok Peruš 1,2 &Rado Turk 1,*1University of Ljubljana, Faculty of Natural Sciences and Engineering, Aškerčeva 12,SI-1000 Ljubljana, Slovenia2University of Ljubljana, Faculty of Civil and Geodetic Engineering, Jamova 2,SI-1000 Ljubljana, Slovenia*Corresponding author. E-mail: Rado.Turk@ntf.uni-lj.siReceived: October 26, 2012 Accepted: November 26, 2012Abstract: The new mathematical model is proposed that enable calculationof true stress – true strain dependence from the results of tensile testsalso after appearing of necking. Based on this model the computerprogram was developed which from the measured final shapes of thetensile specimens and from tensile testing data automatically determinethe time evolution of the specimen’s contour, strain rate andstress-strain relation. In order to tests and validate the model tensiletests at different prescribed strain rates and temperatures on specimensmade of nickel alloy Alloy201 were carried out on thermo-mechanicalsimulator Gleeble 1500D. It was found that after occurrenceof neck the true strain rate is constantly increasing throughout thetest. Further it was found that plastic part of the rod can be well approximatedwith constant and with catenary but Bridgman correctioncan be determined only if catenary is used. Comparison of predictedevolution of minimal radius at the neck with measured one showedexcellent agreement.Izvleček: V delu je opisan nov matematični model, s katerim je mogoče napodlagi rezultatov nateznih preizkusov tudi po pojavu skrčka določitiodvisnost prava napetost – prava deformacija. Na osnovi modela je bilnarejen računalniški program, ki na podlagi izmerjenih končnih oblikOriginal scientific paper

Calculation of stress-strain dependence from tensile tests at high temperatures using ...333specimen as well as in radial direction.Especially due to the latest weaknessstrain and strain rate can be expressedas equivalent strain and strain rate. Athot tensile testing also non-homogeneityof deformation occurs on specimenworking length that is expressedby its necking. It is well known, thatfor tensile test homogenous deformationtakes place only untilappearanceof necking which occurs at strains ofapproximately between 0.2 and 0.3,depending on precision of manufacturingof the tensile samples, onmaterialsinhomogeneity, on temperature gradientalong the tensile axis, etc.When the neck appears, the stress statechange from uniaxial to multi-axialmustbe taken into account. The correctiondue to multi-axiality is usuallydoneby Bridgman correction, whichpresumes that portion of the contourinclose neighborhood of the minimalcross-section of the neck may be characterizedby a single parameter, theradius of curvature of the circle osculatingthe profile at the neck. [1] But obtainingreliable data on stress – strainrelation from tensile tests after appearanceof necking is very difficulttask especially if testing is conductedat elevated temperatures, which is exactlythe case if one wants to study hotworkability of metallic materials.The aims of this study are therefore toevaluate the possibility of applicabilityof tensile test for determination of hotworking properties of metallicmaterialsalso after the appearance of neckingand to introduce appropriatemodel forcalculation of stress-strain dependencefrom the final shapes ofcontours of tensileloaded specimens.Experimental procedureA commercially produced Ni alloyAlloy201 was supplied by Thyssen-Krupp Gmbh as hot drowned rods withchemical composition given in Table1 and equiaxed grain structure with anaverage grain size of about 16 μm.Cylindrical specimens with dimensionsof 25 mm of effective length andof 8 mm in diameter where machinedfrom supplied rods for hot tensile tests(see Figure 1 for specimen’s geometryand dimensions).Table 1. Chemical composition of the commercially pure Ni (Alloy201) tested in massfractions w/%Mo Cr Si S Mg Co Cu P0.001 0.004 0.05 0.001 0.03 0.07 0.006 0.006Mn Ti Fe Sn C V Al Ni0.13 0.04 0.13 0.01 0.02 0.002 0.023 restRMZ-M&G 2012, 59

334 Kugler, G., Terčelj, M., Peruš, I., Turk, R.Figure1. Dimension of specimen’s for tensile testing.(a)(b)Figure2. Schematic representation of temperature control (left), andshaping of contour (right) during hot tensile testing of Alloy201.The hot tensile tests were carried outon Gleeble 1500D thermomechanicaltesting machine. The samples were deformedbetween 8 mm and 11 mm attemperatures from 800 °C to 1000 °Cunder prescribed constant strain ratesbetween 10 –3 s –1 and 10 –1 s –1 assumingthat deformation was homogeneous onentire working length. The temperatureas a function of time during tensile testsis shown on Figure 2a, and specimenduring testing is shown on Figure 2b.Essentially the deformed shape-ofthe-rodafter tensile testing representsthe history of traveling of the crosssectionthat separates the elastic andplastic state of material. [3, 4] The portionof material that in a given momentleft the plastic state preserves its shapeuntil the end of the experiment.Basedon this fact, in what follows, the newmodel for description of evolution ofspecimen’s contours during tensiletesting will be introduced.Description of the mathematical approachModel for description of contour oftensile specimenA cylindrical rod of radius, r, maintainsits rotational symmetry aroundthe longitudinal axis, z, during a tensiletest, and thus its shape at giventime, t, is determined by the rotationalcurve r = r(z, t), which forms its sur-RMZ-M&G 2012, 59

Calculation of stress-strain dependence from tensile tests at high temperatures using ...335 = (, face after rotation around longitudinal elastic parts of the rod. These )twoaxis, z, of the rod. Before the test this points were moving along the () curvecurve is a cylinder r(z, 0) = r 0, where r = r(z, t k), during tensile test. Thus,r 0is the initial radius of the rod. After the rod may be () at = any = time divided (, ) = (, )the test is finished this curve must be into three partscarefully measured to obtain results () in () ()()the form() = = (, ) = ( (, ) + (, ) + = (, )(1)() () ()where t kis the duration of the experi- = = ( Initial (, volume (, ) ) + of the rod (, ) of + (, ))(3)( (), ) = ( (), )() = ment.length, l o, is V 0= πr 2 l 0. The volume is () () ()0conserved during plastic deformation, = (, )and ()thus volume ( for (), ()an arbitrary ) = ( time (), The ) first and last sections belong to, ) + can be expressed (, ) as + = (, ) ()(, ))the elastic part and the middle section ()to the plastic part of the rod. The final ()() ()( (), ) = ( (), ) = ( (), ) = (, )shape of the rod represents the line( (2) of movements of the points which (),() ) =( = (), ) (, ) (, )separate plastic and elastic = (, state () = (, ))of the material. The portion () of the curve () () ( (), ) = ( (), ) = ( (), ) () ()where l(t) is the length of the rod at r = r(z, t k), that lies left of the minimal) cross-section is a monotonically = (, ) = time t. By ()()(, )(, )( (, ) + comparison (, )between + final (, )(, )shape ()of the rod andits shape= (, () = ) = (, )at arbitrarymoment after occurrence of neck, the right is a () monotonically increasing = (, decreasing function )and () the portionon () () () () ()(), ) =but( before(), )the= (end (),ofthe ) ( test, we ascertainthat both shapes differ only in of l lfunction. Thus for the prescribed value (), ) (, = () (), )(t) the value of l d(t) can be calculated ()(, ) the middle, = (, but = (, () ()()) () = (, ) = ( () the end () ()= (, ) = + (, (, )) + (, ))parts are the from the () condition () () same. () Namely, the rod () at the intermediate = time is shorter (, ) () () ()()and it has a smaller(4)(, ) neck. = Thus, (, we () )can conclude that the = ( (, (, ) () = (), ) = ( (), ) = ( (, (, ) ) + ) parts () of the rod, which () have the same From those two +1 + ) ) () () () values the () volume ( (),shape)as=it(is at(),the)end= (of the (),test, )were which is at given time in plastic stateat that ()moment in an elastic state and can be calculated(, ) () = the part, which (, = ) is (, different, )( was in plastic ) = = = (, )( (, ) (, ) (), ) = ( (), ) ()state. Consequently, 1 + () on deformed() () ()( ( (), ) = ( (), ) ) = ( (), ) rod there are always two points that at(5)(,given )moment = separate (, = (, ))the plastic and = ( (, ) + (, )) (, ) (, ) ( 1 + () ) = (, ) () = (, ()) RMZ-M&G 2012, 59 () () ( (), ) = ( (), ) = ( (), ) () ( ) = ( (, ) + (, )) (, () = ) (, ))() () ()

= ( (, ) + = (, () (, ) + )(, )) () ()336() = () () = () ()()(, )Kugler, G., Terčelj, M., Peruš, I., Turk, R.()( (), ) = ( (), ) = ( (, ) + (, ) + (, ))() ( = (), (, = ) = ) ( (), (, ) ) () () () ()The idea for ()reconstruction of()the step the system of linear or non-linear ( intermediate ()(, ) + shapes of the rod ((, ) + is equations must = be solved depending (), (, ) = ()) (), ) (, )on () () now = to find ()the approximate () = (, ) func- (, f(z,t) ) + ≈ r(z,t), () for (, which ) + selected function. The simplest()choice () ()( tion for ()(, ) the ) selection of function is certainlythe constant, which upon rotation ( (), () ) = ( (), ) () ( (), ) = ( (), ) = ( (), ) = (, )()( (), ) = ()()( (), ) = ( (), ) (6) around its axes forms cylinder. Unfortunatelythe conditions (7) and (8) can- (, )( + () (), ) (, =where (, l)c(t) is the length from the beginning of = ()not be fulfilled for approximation with = (, ( ) (), + ) ()(, )(, )) = (, )) therod ()to the ( (, ) () () () (), ) = ( (), ) = ( (), ) () end ofthe ()plastic cylinder. Besides that, the radius ofpart. Since the ()( (), contour of deformed rod curvature of the contour at the minimal is (, smooth, = ) = ( ) it immediately follows for cross-section is needed for calculationthe left end side= (, (), (, ) ) (, ) (, ) = (, ) = (, ))( (), ) = ( (), ) = ( (), ) () () () () () of the Bridgman stress correction, [1] ()but () ()for the approximation by cylinder this( (, = (, (), = ) = ( () (), (, )= ) ((, (), ) ) () (7) radius = (, )is infinite. On the other hand, for () () () = an arbitrary function this radius, R,can () = ()(, ) = (, ) () ()(, ))be calculated from ()( (, and for ) the right () = end (, one (), ) = ( (), ) = ( () (),) ) () () () (,(8) = ()(, ) (, )) = (, = (, )(, ) ) = (, (, ) () = ) () 1 + () 1 + () () () ()(10) ( (, ) () = (, ) ( )Due to the constancy () = (, )= of the volume () (, ) (, ) ( ) = during () plastic = ( deformation, ) = () (, ) it also 1 + () follows ) ( where r minis the minimal radius at time t.= (, ) () () (, ) (9) = 1 + ( = ( (, ) + ) = (, )) ( (, ) + (, ))( Calculation )= () = (, ) (, ) (, ) of stress-strain dependence ()1 + The value of (l c(t) ) = which must be greater ( After ) hot tensile testing the measurementsof deformed rods were carried = ( (, ) + (, )) (,than)the length(,of cylinder) () = (, ))of the same() = volume and 1 + ( (, ))radius ) = r = r(l l, t k) on one out by the measurement microscope, hand = ( and must (, ) be smaller + than (,() l d(t) ) on)which automatically save the ( measured )the other hand, is determined (( iteratively.For the function model that fulfils data only those N points for which r i() ) = = table of data (, ))r i= r i(z i). From measured ) ≤ (( ))[1 = the + (( conditions 2(( )(, = )) ) (6), (7), ((+ (8) )) (, )) (( ))[1 + 2(( )) (( ))] ln(1 + ] ln(1and+(9), the(( r)) o, where2((r ))) ois radius of non-deformed polynomial () = or any other suitable functioncouldrod, are taken into account. Additionally beln( ( ) = ln( (( ))) ( (, )) used. = ( ) =(, ) + In (( any (, case ))[1 ) ) due + ) 2(( to the)) two (( points )) ] ln(1which+are the nearestmentioned () = conditions in (, every )iteration) to the interval of N points= (( )) 2(( )))are also con- = ( ) = ln( (( ))) (( ))[1 + 2(( )) (( ))] ln(1 + (( )) 2(( )))() = ( 1 (, ) ) ) = = 1 = RMZ-M&G 2012, 59 + =

() = (, )() () ()Calculation () = of stress-strain dependence from tensile tests at high temperatures using ... 337 = = (, )(, ) () = (, ) (, ) sidered. For reconstruction of contour ing 1 + () ()()is true V p= V o–V e. For the part of(), ) = the (continuous (), ) = ( function (), is ) needed and the rod which is in the plastic state ( two ) = ( (, ) + (, ) + (, ))thus, cubic splines were applied for additional conditions are valid, namely(, ) interpolation = (, ()which ) ()yields continuous () function r r(z). ()it cannot (be ) longer = than s 1V p⁄πr 2 (l l) (The next step is and cannot be shorter than s 2= l d–l l, (), ) = ( (), ) now the calculation of the volume of respectively.(, ) the rod which undergoes plastic deformation. () Here the Simpson () integration Let construct the function = (, ) = ( (, ) + ()(, )) method [2] = was employed (, )for numericalintegration () ()of equation (2). In thepresent work two different functional(13) () = () = (, ) (, ))(models (), )were= (chosen, (), ) =namely( (),catenary )and constant. ()On deformed part of the(, )rod K equidistant points separated for which on the interval s 1≤ s ≤ s 2has the= (, ) (, ) Δz, were (, selected ) (and ) =( ) () from that () for the root, which is found by bisection. Further,the parameters of the functional final1 +lengthof deformed (( ))[1 + 2(( )) (( ))] ln(1 + (( )) 2 rod, l(t k), wefind (, )( ) = (, )model = ln( which fulfil (( the )))conditions () () (6)–(8) must be determined in every( ) = (11) bisection step. We have the system oflinear equations = () for the polynomial After a number of trials we found that model (constant in the present work) () = (, )( the (, value ) + of Δz = (, 0.5 ) mm ) is most suit-able. In order to meet the condition (4), for the catenary; where the last one isand the system of non-liner equations = = 1 + = ()we find for each value of l l= iΔz corresponding value of l dsolved by the Newton method [2]. Thein every step iteration is interrupted when g(s) < ε, = (, ) (, ) () = i∈[1, 1 + K] by (, bisection. )) For those two where ε is prescribed accuracy. Firstvalues which are at that particular ( ) we determine r minand then from (10)moment in elastic state we calculated the radius of curvature of the contourvolume of ( the ( ) rod, ) = V e, asat the minimal cross-section, R. Both+ 2((of them are combined into the vector. )) (( ))] ln(1 + (( )) 2(( )))Described procedure is iterated until(12) V p> ε 1or l l+ l d+ s

338 Kugler, G., Terčelj, M., Peruš, I., Turk, R.Figure 3. Schematic of the algorithm that from measured final contours of deformedrods and from force-displacement data enables calculations of stress-strain dependence,time evolution of contours and strain rates.RMZ-M&G 2012, 59

, ) (, )(, ) 1 () + = (, ) = (, )Calculation of () stress-strain ( dependence from tensile tests at high temperatures using ... () () )( ) = ) (, ) ()(, )terpolation function for any = ( l are calculated.Finally,= (, from )(, ) Results + and (, Discussion )) 1 + () the experimental results of the tensile test, which was Technical curves and contour( ( ) ()(,conducted) + at constant(, ))temperature, the shapes of deformed rods (true stress is determined, that () is further = Tensile ) = (, ) (, ) (, tests ) were ) carried out by uniaxialtension at prescribed displacementscorrected by Bridgman formula[1]. 1 + Thus, we haverates of anvils and at constant temperatures,( where ) the tension force and dis-) = ( (, ) (, ) + ) ((, )) ) ( ) = ( placement were continually recorded. (( ) = ))[1 + 2(( )) (( ))] ln(1 + (( )) 2(( )))After the test the contours for every deformed (( rod )) were ) carefully measured by( ) = ln( ((() )) = (( ))] ln(1 (, + ) )(( )) 2((microscope. )))The number of measured= ( (, ) + (, ))points on each section of the contour(14) = = ln( (( )) ( ) )) 2(( ))) of deformed rod depended on its localcurvature, but it always exceeded 100 and for the corresponding strain points. Obtained technical curves for = = 1 temperatures + = = ( ) ))[1 + 2(( )) (( ))] ln(1 + (( )) 2(( )))() = (800, 900, (, ))1000) °C, and(15) strain rates of (0.001, 0.01, and 0.1) s –1with corresponding final shapes of rods = 1 = ln( Since + the dependence = (( ))) of strain on time are shown in Figure 4. = ( ) 1 + 2(( is known,)) the (( dependence )) ] ln(1 + of strain ((rate )) 2(( )))on time during the test can be easily After the transition of the material= = determined asfrom elastic to plastic state the stress = ln( 1 + (( ))) = remains uniaxial, but the strain is = (16) three-axial; namely the elongation is uniform at uniformly decreasing of diameter.Uni-axiality of the stress is pre-The computer program which takes as an input the final shape of the contour served until the occurrence of the neck. = 1 oftensile + rod = and data from tensile During the test the measured force istest, i.e. force and length of the rod as initially increasing until it reaches thea function of time and which executes maximum, and afterwards decreasingall the above described steps and enabledetermination of true stress – true strain where the force is at maximumup to the end of the test. The amount ofstrain curves and time evolution of true depends on material and on constitutiverelation σ = σ(ε, ε, T, ...) as well as.strain rate was written in programminglanguage C++. The schematic of this on changing of cross-section of specimen.Technical curve reaches the max-program and algorithm is given on Figure3.imum when dF/dl = 0, where F standsRMZ-M&G 2012, 59 ( ) = ( )339

( ) (( ))[1 + 2(( )) (( ))] ln(1 + (( )) 2(( )))( ) = ln( (( )))(( ))] ln(1 + (( )) 2(( )))340 Kugler, G., Terčelj, M., Peruš, I., Turk, R.for force and l is elongation. From F = ing area of the rod. Since some plasticdeformation occurs always also = (( )))σS, it follows that outside of the working area, this contributesto error. Namely, the slope = = 1 + = of the contour at boundary between(17) outside and inside area is very high. = Therefore the calculated lengths ofrods at initial steps of deformationwhere the constancy of the volume has are too long, and cross-sections arebeen taken into account. Therefore the even smaller than those obtainedforce is maximal when dσ/dε = σ. at the end of deformation. Movingalong the deformed contour resultsFormation of contours during in shortening of calculated lengthstrainingas well as in increasing the minimalcross-section. According to theThe key parameters that for the selectedfunctional model determine how present model the length of the rodaccurate the shape of contour can be initially increases with strain, whichdetermined are the volume V o, which is nonsense. To avoid this inconsistencythe contour was calculated withundergo plastic deformation, and thelocal slopes of the final contour. Of our model only after the calculatedcourse, the last condition is not valid length begins to increase with strain,for the simplest i.e. cylindrical model, before that the contour was calculatedassuming homogeneous defor-since the boundary conditions (7) and(8) cannot be fulfilled. Consequently, mation. The examples of calculationthe shapes of contours calculated by of the rod shapes evolution duringcylindrical model are unrealistic (see deformation for cylinder and for catenaryat temperatures 1000 °C andFigures. 5a and c), but nevertheless, asit will be demonstrated later, this modelgives surprisingly good prediction 0.1 s –1 are shown on Figure 5. If one900 °C, and prescribed strain rate ofof the evolution of the minimal radius wants to calculate the dependenceof the rod within the neck during entire of true stress on strain, the minimaltensile test.cross-section, which is obtained fromreconstruction of contour of the rod,As we mentioned earlier the volume, must be given for every strain. TheV o, is obtained by integration of the dependence of minimal radius onfinal contour of the rod along the z- elongation for two temperatures calculatedby catenary model is givenaxis considering condition r(z) ≤ r o,where r ois initial radius of the work-on Figures 6a and 6b.RMZ-M&G 2012, 59

Calculation of stress-strain dependence from tensile tests at high temperatures using ...341Figure 4. Technical curves force-elongation obtained wit tensile tests for strain ratesof (0.001, 0.01 and 0.1) s –1 at temperatures of 800 °C (a), 900 °C (b), and 1000 °C (c)together with corresponding measured final shapes of deformed rods (d)–(f).Figure 5. The calculated shapes of tensile rods for various stages of deformations attemperature of 1000 °C and strain rate of 0.1 s –1 for cylindrical (a) and for catenarymodel (b). Calculation for cylindrical (c) and catenary (d) models at T = 900 °C andstrain rate of 0.1 s –1 .RMZ-M&G 2012, 59

342 Kugler, G., Terčelj, M., Peruš, I., Turk, R.Figure 6. Comparison of dependence of minimal radius of deformed rod on elongationcalculated by models for catenary, cylinder, and for assumption of homogeneous deformationfor ε = 0.1 s –1 at T = 1000 °C (a), and T = 900 °C (b). Evolution of the radius of.the circle osculating the profile at the neck, R B, and corresponding dependence of Bridgmancorrection coefficient, k B, on elongation calculated by catenary model at T = 1000°C (c), and T = 900 °C (d).Figure 7. Comparison of dependence of minimal radiuses on elongation between measurementsconducted by digital camera and calculated by studied models (catenary, cylinder,homogeneous deformation) for ε = 0.1 s –1 at T = 950 °C (a), and at T = 900 °C (b)..RMZ-M&G 2012, 59

Calculation of stress-strain dependence from tensile tests at high temperatures using ...343For comparison the minimal radiusescalculated by cylindrical model and byassumption of homogeneous deformationare also given. It can be seen thatthe radius obtained by cylindrical modelis very close to one obtained by catenary,whereas as expected the radiusaccording to homogenous deformationmodel after occurrence of necking startdo deviate from values predicted by ourmodels. Deformation is homogeneousapproximately up to elongation of 2mm that corresponds to strain ≈0.2. Asit was already mentioned, the transitionfrom homogeneous to nonhomogeneousdeformation leads to transition ofuniaxial to three-axial stress state. Forcalculation of Bridgman correction, k B,the radius of the circle osculating theprofile at the neck, R B, is needed. TheR Bis calculated by equation (10) fromreconstructed contours. The evolutionof R Band k Bare given on Figure 6c,and 6d, respectively. When the contoursare calculated by the homogeneousdeformation model, we set k B≡ 1,consequently the dependence of k B(Δl)is discontinued at transition betweenboth areas, with negligible error.Calculated values of the time evolutionof the minimal radius of the tensilespecimens were compared withthe values obtained from analysis ofthe pictures which were recorded bya digital camera, and we obtained reasonableagreement. These results areshown on Figure 7, were the maximalestimated errors for minimal radiusmeasured with camera are denoted.Due to intensive radiation from hotsamples, the sharp boundary betweenthe rod and surrounding was indistinct,thus the determination of real minimalradius was hindered.True stress–true strain curvesFrom technical force-elongationcurves the true stress–true strain curveswere determined by employing all theprocedures explained in previous sections.They are shown on Figures 8a–c,whereas Figures 8d–e show the actualvariation of strain rates during the tests.For higher temperatures and/or lowerstrain rates the flow stress initiallyraises until a maximum is reachedwhen hardening and softening are inbalance. With increasing deformation,softening prevails over hardening andflow stress decreases. At strains ε >0.2 flow stress starts to increase andincreases until the end of the experiment.This kind of behaviour in thelater stages of deformation is a consequenceof the continuously increasingstrain rate after the appearanceof necking. For the same reason flowcurves for low temperatures and/orhigher strain rates do not reach a maximum.Thus, we can conclude thatafter necking, the stress-strain curvesare not flow curves as by definitionflow curves are stress-strain curves atconstant temperature and strain rate.RMZ-M&G 2012, 59

344 Kugler, G., Terčelj, M., Peruš, I., Turk, R.Figure 8. True stress-true strain curves, obtained by tensile tests for prescribed strainrates of (0.001, 0.01) s –1 , and 0.1 s –1 at temperatures of 800 °C (a), 900 °C (b), and 1000°C (c) and corresponding variation of actual strain rate during the tests (d)–(f).But in the future a series of carefullychosen testing conditions is planedwith the aim to examine the possibilityof finding the model that would themovements of jaws during the tests insuch a way that constant true strain ratewould be maintained during the entiretest. Then it would be possible to determineflow curves with tensile testing tostrains that are comparable with strainsthat can be obtained with compressiontesting.ConclusionsIn this work a new mathematical modelfor calculation of true stress – truestrain dependence from the results oftensile tests, which can be used alsoafter appearing of necking, was proposed.Furthermore the model was implementedinto the computer programthat enables determination of stressstraincurves from measurement ofcontours of deformed rods. The modeland the computer program were validatedby employing tensile tests forcombinations of three different strainrates and temperatures on Gleeble1500D testing machine for Ni alloy Alloy201.The main findings can be summarizedas follows:1. It was found that, if the jaws of testingdevice are controlled in such away that constant strain rate is obtainedif homogeneous deformationis assumed, after appearanceof necking the true strain rate is nolonger constant, but it is increasing.Thus, stress-strain curves obtainedin this way are not true flowRMZ-M&G 2012, 59

Calculation of stress-strain dependence from tensile tests at high temperatures using ...345curves, as by definition flow curvesare stress-strain curves at a constantstrain rate.2. In the present work two functionsfor description of evolution of thepart of the contour which is in givenmoment in the plastic state, weretested, i.e. constant (approximationwith cylinder) and catenary. Basedon the comparison of the predictedevolution of contour and contoursobtained by measurements withfilm camera it was found that bothfunctions are capable of descriptionof evolution of minimal radiusof the rod in the neck with accuracywithin the measurement error.3. The main problem of applying thesimplest function, i.e. the constant,is that it is not possible to determinethe evolution of radius of curvatureof the couture at the minimalcross-section and consequentlyBridgman stress correction due tothree-axiality of the stress cannotbe applied since for constant thiscurvature is infinite. On the otherhand using catenary this problem isavoided and true stress – true straincurves including Bridgman correctioncan be determined.4. It could be possible to predeterminethe movements of jaws during thetests in such a way that constant truestrain rate would be maintained duringthe entire test or at least up tothe true strains up to the value of 1.0,but this will require many more testsfor different materials and at differentthermo-mechanical conditions.References[1]Bridgman, P. W. (1952): Studies inLarge Plastic Flow and Fracture,McGraw-Hill, NY.[2]Press, W. H. et. al. (1988): Numericalrecipes in C, Cambridge UnivrsityPress, Cambridge.[3]Kugler, G. (2004): Prediction of hotworkability of metals by use ofcellularautomata, Univrsity of Ljubljana,NTF, Ljubljana.[4]Turk, R. (1982):Postavitev modela zaoceno tople preoblikovalnosti kovin,Univerza v Ljubljani, FNT, Ljubljana.RMZ-M&G 2012, 59

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RMZ – Materials and Geoenvironment, Vol. 59, No. 4, pp. 347–362, 2012347Petrochemical characteristics and geotechnical properties ofcrystalline rocks in the archean-proterozoic terrain ofIjero-Ekiti, southwestern NigeriaPetrokemijske značilnosti in geotehnične lastnosti kristaliničnihkamnin v arhajsko-proterozojskem kompleksu Ijero-Ekitiv jugozahodni NigerijiOluwatoyin O. Akinola 1 & Abel O. Talabi 1, *1University of Ado-Ekiti, Department of Geology, Nigeria*Corresponding author. E-mail: soar_abel@yahoo.comReceived: October 3, 2011 Accepted: August 3, 2012Abstract: The Precambrian basement rocks around Ijero Ekiti, southwesternNigeria were investigated with a view to elucidating its compositionalfeatures and geotechnical characteristics that may be relatedto industrial application. As part of the study approach, geologicalappraisal of the study area through systematic mapping was undertaken.Six samples each of the nine basement rocks were analysedfor major elements using the Inductively Coupled Plasma AtomicEmission Spectrometry (ICP-AES) technique from Activation Laboratories,Ontario Canada and physical tests were conducted in TreviFoundations, Lagos.The systematic mapping of the study area revealed rocks comprisingof the migmatite gneiss complex, quartzite, mafic-ultramafic assemblageand schistose rocks with paucity of granite and pegmatiteforming steeply dipping intrusions into the older rock sequences. Petrographicexamination indicates quartz, albite, biotite, hornblende,olivine, pyroxene and biotite as the common mineral constituents occurringin the basement rocks. Furthermore, from analytical result,SiO2, Al2O 3and Fe2O3accounts for a substantial percentage of theoxides in the rocks. However, calc gneiss has appreciably high CaO(15.15 %) and MgO (13.49 %) values. TiO 2and P2O 5are less than0.1 % and 0.3 % respectively in all the rocks. Result of physical testsincluding specific gravity range between 2.54 g/cm 3 and 2.85 g/cm 3 ;Original scientific paper

348 Akinola, O. O., Talabi, A. O.compressive strength 32.4–84.50 N/mm 2 ; wet density 2.01–2.30 g/cm 3 ;water absorption capacity 0.02–0.24 %; porosity 0.01–0.58 % and pH6.7–7.3. Industrial assessments using the evaluated physical propertiesindicate that the gneisses, quartzite, epidiorite and granite of the area aresuitable for construction purposes.Izvleček: Kamnine predkambrijske podlage z območja Ijero Ekiti vjugozahodni Nigeriji smo raziskali z namenom opredeliti njihovosestavo in geotehnične lastnosti v luči njihove gospodarskeuporabnosti. Del raziskave je obsegal sistematično geološko kartiranještudijskega ozemlja. Nadalje so bile v šestih vzorcih odvsake glavne kamnine podlage določene glavne kemične prvine zinduktivno vezano plazemsko atomsko emisijsko spektrometrijo(ICP- AES) v Activation Laboratories v Ontariu v Kanadi, medtemko so opravili fizikalne preiskave v laboratoriju organizacije TreviFoundations v Lagosu v Nigeriji.Geološko kartiranje območja je razkrilo kamnine kompleksa migmatitnegagnajsa, kvarcit, mafično-ultramafično združbo in skrilavekamnine z redkimi granitnimi in pegmatitnimi intruzijami,strmo vtisnjenimi v starejših kamninskih skladovnicah. S petrografskoraziskavo so bili ugotovljeni kremen, albit, biotit, rogovačo,olivin, piroksen in biotit kot poglavitni minerali v kamninahpodlage. Analizni rezultati kažejo, da tvorijo glavni delež oksidovv kamninah SiO 2, Al 2O 3and Fe2O3. Izjema je kalcitni gnajs, ki vsebujevisoke deleže CaO (15,15 %) in MgO (13,49 %). VsebnostiTiO 2in P2O 5sta v vseh preiskovanih kamninah manjši od 0,1 %oziroma 0,3 %. Rezultati fizikalnih preizkusov so naslednji: prostorninskamasa 2,54–2,85 g/cm 3 , tlačna trdnost 32,4–84,50 N/mm 2 , gostotav vlažnem stanju 2,01–2,30 g/cm 3 , vpojnost vode 0,02–0,24 %,poroznost 0,01–0,58 % in pH 6,7–7,3. Iz ugotovljenih fizikalnihlastnosti sledi, da so gnajsi, kvarcit, epidiorit in granit s tega območjaprimerni za uporabo v gradbeništvu.Key words: Archean-proterozoic, geotechnical characteristics,basement rocks, compressive strengthKljučne besede: arhaik-proterozoik, geotehnične lastnosti, kamninepodlage, tlačna trdnostRMZ-M&G 2012, 59

Petrochemical characteristics and geotechnical properties of crystalline rocks in the ...349IntroductionRugged relief characterized by prominentinselbergs is a common feature ofmany parts of Nigeria and in particularEkiti State in the southwestern part ofthe country. These rocks, apart from notgenerating revenue from tourism, havenot been fully exploited for other majoreconomic purposes considering theavailable enormous quantity that occurin the area. Underutilization of theserocks may be attributable to insufficientgeological information on the assessmentof their properties on the one handand shallow knowledge of what theycould be used for on the other hand.These crystalline rocks could serve asraw material in most construction industriesand as such contribute tremendouslyto the socio-economic developmentof the study area. This investigationis therefore aimed at evaluatingthe compositional features and physicalcharacteristics of Ekiti crystalline rocksvis-à-vis their industrial application.Regional Geological SettingNigeria lies within the Pan-Africanmobile belt specifically between theCongo craton to the southeast andWest African craton to the west (Figure1). Geology of Nigeria is made ofsedimentary and crystalline rocks inalmost equal proportions. The sedimentaryrock sequences occupy themarginal and intracontinental basinsand belong to the Cretaceous-Recentage spectrum and lie unconformablyon the basement complex rocks.The rocks constituting the basementcomplex (Figure 2), despite disagreementson lithological delineations, areloosely categorized into three majorgroups: the migmatite-gneiss complex,the schist belts and the Pan-AfricanGranites (Elueze, 2000). The migmatitegneiss complex 2.0–3.0 Ga; (Rahamanet al., 1988, Dada & Briqueu,1998) is the oldest and most abundantrock type in the basement and is a productof several tectonothermal eventsthat have brought rocks of variousorigins together. In addition, the schistbelts, comprise low-grade metasedimentsand metabasic rocks that cropout in a series of distinctly N-S trendingsynformal troughs infolded intothe crystalline migmatite-gneiss complex.They are about the best-studiedgroup of rocks in Nigeria (Russ, 1957,Truswell & Cope, 1963) because ofthe mineralization such as gold, BandedIron Formation (BIF), tin, tantalum,niobium and marble, associated withthem (Oyinloye, 2006). These rocksshow distinctive petrological, structuraland metallogenic features (Okunlola,2005). The schist belts in southwesternNigeria include Iseyin-Oyan,Egbe-Isanlu, Ife-Ilesha and Igarraschist belts (Rahaman, 1976; Odeyemi,1977; Annor et al 1996). OthersRMZ-M&G 2012, 59

350 Akinola, O. O., Talabi, A. O.are the Lokoja-Jakura, Toro-Gadabuikebelts (Muotoh et al 1988, Okunlola,2001). The geochemistry of these rocksconfirms their sedimentary nature butthat of associated mafic and ultrabasicrocks has generated much controversy.The Older Granites display the mostpervasive tectonic fabric symbolizingigneous reactivation attributableto the Pan-African events (Oyawoye,1964). The Older Granites in all casesinclude rocks of a wide range of compositions,structures and textures. TheOlder Granite is typically a fine-mediumgrained to coarse porphyritic rockwhose composition range from tonalitethrough granodiorite to granite and syenite.The lithological framework, deformationand metamorphism of thebasement rocks are established in theworks of Mccurry (1976), Ajibade(1976, 1980), Odeyemi (1988), Rahaman(1976, 1988), Egbuniwe (1982)and Elueze (1981). The geology ofIjero-Ekiti area has been reported in literatureas part of the basement complexof southwestern Nigeria by Mccurry(1976), Tuner (1983), Rahaman et al,(1988). This area is an Archaean-EarlyProterozoic terrain Grant (1970).Figure 1. Map showing Nigeria within the Pan-African province between Congo andWest African cratons (Ajibade et al, 1988)RMZ-M&G 2012, 59

Petrochemical characteristics and geotechnical properties of crystalline rocks in the ...351Lithological relationshipGeological appraisal through systematicmapping reveals that there arenine main lithologic units in Ijero area.They are: migmatite-gneiss, biotitegneiss,calc-gneiss, quartzite, epidiorite,biotite schist, amphibole schist,granite, and pegmatite (Figure 3).Migmatite-gneiss occurs towards theeastern part covering about two-fifthof the study area. The rock exposuresoccur as highly denuded hills of essentiallyfine textures with closely spacedalternating bands of leucocratic andmelanocratic minerals. Outcrops ofbiotite-gneiss occur towards the west.They are characteristically low lying,fine textured, and conspicuously foliatedwith abundance of platy biotiteminerals sandwiched into zones thatare markedly distinguishable fromthe light-coloured quartzo-feldsparticportions. In some areas, the foliationsbecome so indistinct that the bandsare lost leaving various indiscerniblestreaks of light and dark minerals.Calc-gneiss has grey to greenish colourwith weakly developed foliations.Figure 2. Generalized Geological Map of Nigeria showing the Basement ComplexRocks, Schist Belts, the Younger Granites and the Sedimentary Basins. (Black, 1980)RMZ-M&G 2012, 59

352 Akinola, O. O., Talabi, A. O.It is devoid of quartz vein intrusionsand is restricted in occurrence only toa narrow strip in the eastern part ofIjero town. Quartzite occurs as ridgeof steeply dipping, massively bedded,fine-medium grained bodies or an environmentcharacterized by the abundanceof quartz rubbles. Outcrops ofepidiorite (a dense fine grained, darkcoloured rock) are poorly exposed andare restricted to the southern part ofthe study area biotite schist and amphiboleschist occurs toward the centralpart of the area and are borderedin the west and east by biotite-gneissand migmatite-gneiss respectively(Figure 3). They are highly succeptibleto weathering and remarkably displaya North-South foliation trend withpoorly exposed outcrops occupyinglowlands adjourning quartzite ridges,gneisses and granite pegmatites. Graniteoccurs as minor intrusive bodieswhile the pegmatite occur as distinctdykes of variable dimensions that is,veins and veinlets within the gneissicbodies with few cases of occurrencein batholitic masses.Figure 3. Geological map of Ijero Ekiti area (Okunlola & Akinola, 2010)RMZ-M&G 2012, 59

Petrochemical characteristics and geotechnical properties of crystalline rocks in the ...353Materials and MethodsThe study involves systematic geologicalmapping and samples were collectedby standard geological techniquesduring which thin section study of eachrock unit collected were undertaken.Caution was taken to ensure that thesamples were fresh, unweathered anduncontaminated. Subsequently, forgeochemical investigations, collectedsamples were dried at 60 °C, crushed,pulverized and sieved using sieve size0.075 mm. 0.2 g samples aliquot wasweighed into a graphite crucible andmixed with 1.5 g of LiBO 2/LiB 4O 7. Thesample charged was heated in a mufflefurnace for 30 min at 980 °C. Thecooled bead was dissolved in 100 m/Lof 5 % HNO 3(ACS grade nitric acid)in de-mineralized water. An aliquot ofthe solution was poured into a propylenetest tube. Calibration standard andverification standard were included inthe samples sequence. Samples solutionwas aspirated into an ICP Mass Spectrometer(Perkin-Elmer Elan 9000) forthe determination of the major oxides atthe Activation Laboratories in OntarioCanada. In addition, physical test werecarried out on the basement rocks todetermine their industrial characterization.The tests conducted include specificgravity (SG), compressive strength(CS), wet density (WD), water absorptioncapacity (WAC) and porosity (P,%) following the American Society forTesting and Materials 1985, D2487-83procedures while pH determinationswere carried out using a multiparameterportable meter (model Testr-35). Bulkporosity determination is the measure ofthe quantity of water which a rock willabsorb when immersed in water andis measured by , the difference betweenthe dry weight of the sample and theweight after soaking expressed as percentageof the dry weight. Compresssivestrength is determined by staticallyloading a cylinder of rock to fracture,the load being applied across the upperand the lower faces of the sample.PetrographyPetrographic examinations indicatethat migmatite-gneiss contains feldspar,quartz, muscovite and biotite. Thebiotite content is low and mineral alignmentis less pronounced. Other essentialcomponents include ferromagnesianminerals like hornblende. Quartz andfeldspars alone constitute up to 70 % ofthe rock in thin section. Feldspar is secondto quartz in abundance while ferromagnesianand opaque minerals such asgarnet and magnetite constitute the colouredminerals (Figure 4). The mineralconstituents of biotite gneiss are similarto those of the migmatite-gneiss exceptthat they appeared stretched and elongatedsuch that the longer axis appearsin the same direction. A larger percentageof the biotite occurs in groundmassand mineral outlines are well defined.RMZ-M&G 2012, 59

354 Akinola, O. O., Talabi, A. O.Figure 4. Photomicrograph of migmatite gneiss in transmited light showing crosshatchedtwinned microcline (M), large plates of biotite (B), fine grained quartz crystals(Q) and muscovite (Mu)Calc-gneiss is mainly composed of calcite,quartz with muscovite. Most of theminerals show evidence of strain andare altered. Calcite, quartz and muscoviteare the dominant minerals accountingfor 90 % of the modal composition.Ferromagnesian minerals like olivine,pyroxene and hornblende dominate themodal composition of epidiorite (Figure5). Quartz, muscovite, hornblendeand accessory opaque minerals dominatethe composition of biotite schist.Quartz occurs as small, colourless andsometimes cloudy xenomorphic crystals.Accessory zircon occurs as shortidiomorphic crystals while the opaqueminerals are few but existing as scatteredeuhedral grains (Figure 6). Biotiteoccurs in dominant amounts andforms the major groundmass minerals.In quartzite, quartz occurs as granoblasticand unaltered euhedral crystalswith well-defined outlines. It exhibitsweak birefringence, low relief withwavy extinction. However, some of thequartz grains appear cloudy.Muscoviteform supporting minerals as they occupyintergranular spaces of interlockingquartz crystals and sometimes occuras colourless elongated plates. In granite,the feldspars are large, well-formedcrystals of albite while quartz occurs asirregular masses of colourless and unalteredgrains.RMZ-M&G 2012, 59

Petrochemical characteristics and geotechnical properties of crystalline rocks in the ...355Figure 5. Photomicrograph of fine grained epidiorite in transmitted light showingdominance of ferromagnesian minerals, olivine (O), Pyroxene (P), Quartz (Q) andHornblende (H)Figure 6. Photomicrograph of fine-grained biotite schist in transmitted light showingeuhedral quartz (Q), albite (A), hornblende (H), and platy biotite (B).RMZ-M&G 2012, 59

356 Akinola, O. O., Talabi, A. O.In pegmatite, the feldspars exist asporphyries of microcline with its characteristicstrong cross hatched twiningand strong to weak micro perthitic intergrowth.Tourmaline crystals exhibitlong needle-like prismatic shapes withacicular habit (Figure 7).Modal analysis (Table 1) shows thatquartz is adequately represented inmost of the basement rocks withquartzite, granite, gneisses and pegmatiteshowing larger percentages whileepidiorite, amphibole schist and calcgneissrecord substantially low values.Plagioclase is well represented ingranite, pegmatite and the gneisses butwith low representation in the schistoserocks. Biotite is another mineralthat cut across most of the basementrocks. However, highest percentagesare recorded in biotite schist and biotitegneiss while calc-gneiss does notshow any trace of the mineral at all. Asregards amphibole schist, hornblendehas the highest percentage while it is ofan average value in epidiorite. Olivineand pyroxene are only represented inepidiorite while tourmaline and lepidoliteare present only in pegmatite.Results and discussionGeochemical featuresGeochemical result (Table 2) showsthat average SiO 2content of all thebasement rocks are high and rangefrom lowest value in epidiorite (55.72%) to highest value in granite (73.61%). The gneisses have average SiO 2similar to those found around Ileshaarea (Elueze, 1981). Alumina contentranges from lowest in calc-gneiss(9.23 %) to higher values in amphiboleschist (15.62 %) and highest in biotiteschist (18.03 %). The mean Al 2O 3contentof the schistose rock around Ijerois generally higher than similar rocksencountered around Ibadan (Okunlolaet al, 2009)Mean Fe 2O 3content of Epidiorite(11.16 %)) and biotite schist (8.53)are comparable. These values arehigher than biotite gneiss (7.02 %) andpegmatite (6.49 %). Low mean MnOvalue is common to all the basementrocks except quartzite (2.18 %) whichrecords the highest, and this valueis higher than calc-gneiss (1.64 %).All other basement rocks have averageMnO values that are less than 0.6%, for instance, epidiorite and biotiteschist both record 0.08 %. Mean MgOcontent of Calc-gneiss (13.49 %) isslightly lower than epidiorite (14.80%). Other rocks, amphibole schist(6.25 %), biotite gneiss (3.08 %), biotiteschist (8.94 %), quartzite (1.00 %)have low mean values while the remainingbasement rocks record lowervalues. Average CaO values of migmatitegneiss (2.51 %), biotite gneiss(2.14 %) and amphibole schist (2.04%) are comparable. However, theseRMZ-M&G 2012, 59

Petrochemical characteristics and geotechnical properties of crystalline rocks in the ...357Figure 7. Photomicrograph of pegmatite in transmitted light showing tourmaline crystals(T), Quartz (Q) and muscovite (M).Table 1. Modal composition of the basement rocks in Ijero-Ekiti area (%)Minerals *MG *BG *CG *QZ *EP *BS *AS *GR **PGQuartz 48 42 25 56 17 34 18 46 37Plagioclase 22 18 4 10 35 12Microcline 12 7Calcite 36Muscovite 32 29 11 26Biotite 23 32 10 13 58 15 5 8Hornblende 4 6 18 4 32 6 1Olivine 17Pyroxene 21 5Tourmaline 8Epidote 6 4 3Lepidolite 4Opaque 3 3 5 2 9 2Others 1 1MG (Migmatite gneiss), BG (Biotite gneiss), CG (Calc-gneiss), QZ (Quartzite), EP (Epidiorite),BS (Biotite schist), AS (Amphibole schist), GR (Granite), PG (Pegmatite); * Average of 6samples, ** Average of 5 samplesRMZ-M&G 2012, 59

358 Akinola, O. O., Talabi, A. O.values are lower than quartzite (6.54%), epidiorite (4.04 %), and calcgneiss(15.15 %). Mean Na 2O valueof migmatite gneiss (3.32 %) and biotitegneiss (3.00 %) are comparable.These values are higher than epidiorite(1.97 %) and pegmatite (2.38 %).While calc gneiss (1.08 %), quartzite(1.21 %) and amphibole schist (1.34%) are within similar range. Averagepotash content of pegmatite (6.77 %)is higher than the comparable valuefor migmatite gneiss (4.18 %) andbiotite schist (4.08 %) while lowermean values are recorded for biotitegneiss (3.86 %), quartzite (1.96 %)and amphibole schist (1.70 %). Otheroxides, TiO 2and P 2O 5do not followany discernible pattern and their valuesare generally less than 0.5 % in allthe basement rocks. Loss on Ignitionvalues are generally low and fall between1.07 % in pegmatite and 5.27 %in biotite schist.Physical and mechanical featuresThe result of the physical tests (Table 3)shows that amphibole schist has the lowestspecific gravity value of 2.54 g/cm 3while biotite gneiss has the higher valueof 2.85 g/cm 3 . Compressive strengthvalues fall within a wide range withamphibole schist having the least value(32.4 N/mm 2 ) and Granite the highestvalue (84.5 N/mm 2 ). Lowest wet densitywas obtained for amphibole schist(2.01 g/cm 3 ) and highest for migmatitegneiss (2.31 g/cm 3 ), Water Absorptioncapacity values are generally low andquartzite records the lowest (0.04 %)while amphibole schist (0.28 %) recordsthe highest. Biotite gneiss andquartzite record the lowest bulk porosityvalue of 0.01 % while the highestvalue (0.58 %) was in biotite schist. ThepH values range generally between 6.7and 7.4 with the least and highest valuein migmatite gneiss/granite and biotiteschist respectively.Industrial assessmentPhysical tests on the basement rocksare to ascertain their usefulness asbuilding materials. Building stonesdenote pieces of rock that may undergocutting, sawing, shaping andsometimes polishing and still be usefulfor construction purpose. The mainrequirements for building stones arestrength, durability, workability, andavailability. To be useful for constructionpurpose, a minimum compressivestrength of 36 N/mm 2 (367.2 kg/cm 2 ) isrequired (ASTM, 1970). Many of theBasement rock including migmatitegneisses, biotite gneiss, calc gneiss,quartzite and granite meets the abovespecification (Table 3).However, the schistose rocks have lowercompressive strengths due to theirfissility. Although, pegmatite meetsthe minimum strength requirement foruse as building stone, its large-sizedparticles are a disadvantage. Migmatiteand biotite gneiss are highly meta-RMZ-M&G 2012, 59

360 Akinola, O. O., Talabi, A. O.A quarry site is located along Epe roadwhere a gneissic outcrop serves as asource of stone aggregate for more thanthree decades. Local sources indicatethat most of the roads in the area werebuilt with products from this stone mill.The major quartzite ridge of the area hasbeen quarried locally to produce materialsfor foundation works and cementmixing for concrete slabs.ConclusionIjero-Ekiti is within the BasementComplex terrain of southwestern Nigeriaand underlain by gneisses, quartzite,epidiorite, schists, granite and pegmatite.The granite and pegmatite formsteeply dipping intrusions into olderrock sequences. Most of the basementrocks are rich in quartz, feldspars, biotiteand hornblende. Calc-gneiss is enrichedin calcite and epidiorite has highpercentage of ferromagnessian mineralsincluding hornblende, biotite, andpyroxene. The mineralogical variationsalso reflect in the chemical compositionof the rocks for instance, calc gneisshas high percentage of CaO and MgOwhereas the gneisses, quartzite, graniteand pegmatite are highly siliceous.Physical properties of the basementrocks indicate that they possess averagespecific gravities, moderate wetdensities, high compressive strengths,and low porosities. A slightly acidic tomildly basic pH characterizes the rocksand they are comparable to similarrocks found elsewhere within the basementcomplex. Economic evaluationindicates that the gneisses, quartzite,epidiorite and the granite have compressivestrength values within the limitsrequired for use as foundation materialand building stones.AcknowledgementThe authors wish to acknowledge withgratitude all those who assisted in thegeological field work. Mr. O. Olaifaof the department of Earth Sciences,Olabisi Onabanjo University Ago-Iwoye and Mr. Nasirudeen of ObafemiAwolowo University, Ile-Ife are appreciatedfor their considerable supports.Numerous colleagues and studentswho contributed in various ways arealso acknowledged. Chemical analysiswas executed at Actlabs laboratories,Canada. Dr. A. F. Abimbola was exceptionallysupportive.ReferencesAjibade, A. C. (1976): Provisional classificationand correlation of the schistbelts of Northern Nigeria. Kogbe, C.A. Ed. Geology of Nigeria. Eliz. Pub.Co. Lagos, pp. 85–90.Ajibade, A. C. (1980): Geotectonic evolutionof the Zungeru region Nigeria.Unpub. Ph.D Thesis Univ. Col. Wales,303p.RMZ-M&G 2012, 59

Petrochemical characteristics and geotechnical properties of crystalline rocks in the ...361Ajibade, A. C., Woakes, M. R & Rahaman,M. A. (1988): Proterozoic crustaldevelopment in the Pan-Africanregime of Nigeria. In PrecambrianGeology of Nigeria, GSN Esho Pub.Kaduna.Annor, A. E., Olabaniyi, S. B. & Mucke,A. (1996): A note on the Geology ofIsanlu areas in the Egbe-Isanlu schistbelt S. W. Nigeria. Min. Geol., Vol.32, No. 1, pp. 47–52.American society for testing & materials(1970): The sampling of soil and rock.Special Tech. Pub., p. 483.Black, R. (1980): Precambrian of WestAfrica Episode. Vol. 8, No. 4, pp. 1–8.Blyth, F. G. H & De Freitas, M. H.(1974): Geology for Engineers sixthedition. Edward Arnold (Pub.) Ltd.,London, pp. 296–316.Dada, S. S & Briqueu, L. (1998): Pb-Pband Sr-Nd isotopic study of meta igneousrocks of Kaduna: Implications forArchean mantle of Northern Nigeria.32nd Annu. Conf. Nig. Min. Geosci.Soc., Abst., 57pp.Egbuniwe, I. G. (1982): Geotectonic evolutionof the Maru belt N.W. Nigeria.Unpublished. Ph. D. Thesis Universityof Wales Aberystwyth.Elueze, A. A. (1981): Goechemistry andpetrotectonic setting of meta sedimentaryrocks of the schist belt of Ileshaarea S.W; Nigeria, Precambrian Res.19, pp. 167–177, Journ. Min. Geol.,Vol. 18, No. 1, pp. 167–169.Elueze, A. A. (2000): Compositional appraisaland petrotectonic significanceof the Imelu banded ferruginous rockin the Ilesha schist belt, southwesternNigeria, J. Min. Geol., Vol. 36, No. 1,pp. 8–18.Grant, N. K. (1970): Geochronology ofPermian basement rocks from Ibadan,southwestern Nigeria; Earth and PlanetaryScience Letters, Vol. 10, p. 29–38.Grant, N. K. Hickmann, M., Burkholder,F. R & Powell, J. L (1972): Kibaranmetamorphic belt in Pan-Africa domainof West Africa. Nature phys. Sci.Vol. 238, 90–91.Mccurry, P. (1976): The Geology of thePrecambian to lower paleozoic rocksof northern Nigeria a review of Geologyof Pub. Co, Lagos.Muotoh, E. O. G., Oluyide, P. O., Okoro,A. U & Muogbo, O. E. (1998): TheMuro hills banded iron formations, In:Oluyide, P. O, Mbonu, W.C., Ogezi,A. E, Egbuniwe, I. G, Ajibade, A. C& Umeji, A. C (eds) Precambrian Geologyof Nig., G. S. N Kaduna, pp.219–227.Odeyemi, I. B. (1977): On the basementrocks of Bendel State of Nigeria.Unpub. Ph.D. Thesis, University ofIbadan.Odeyemi, I. B. (1988): Lithostratigraphyand structural relationship of the upperPrecambrian metasediments inIgarra area southwestern Nigeria. Inthe Precambian Geology of Nigeria. P.O Oluyide, W. C Mbonu, A. E Ogezi,I. G. Egbuniwe, A. C. Ajibade, A.CUmeji (eds). GSN, Esho Pub. Kaduna.Okunlola, O. A. (2001): Geological andCompositional investigation of Precambrianmarble bodies and associatedrocks in the Burum and Jakura areas,Nigeria, unpublished Ph.D. Thesis,University of Ibadan. 251p.Okunlola, O. A. (2005): MetallogenyRMZ-M&G 2012, 59

362 Akinola, O. O., Talabi, A. O.of Ta-Nb mineralization of PrecambrianPegmatites of Nigeria, Books ofAbstracts, Nigeria Mining and GeosciencesSoc. Int. Mineral Wealth.137/2005.Okunlola, O. A., Adeigbe, O. C & Oluwatoke,O. O (2009): Compositionalfeatures of Schistose rocks of Ibadanarea, Southwestern Nigeria. Earth ScienceResearch Journ. Columbia, Vol.13, No. 2, pp 2943.Okunlola, O. A & Akinola, O. O. (2010):Petrochemical characteristics of thePrecambrian rare metal pegmatite ofOke-Asa area, South-western Nigeria:implication for Ta-Nb mineralization.RMZ-Material and Geoenvironment,Vol. 57, No. 4, pp. 525–538.Oversby, V. N. (1975): Lead isotope studyof Aplites the precambian basementrocks near Ibadan, southwestern Nigeria.Earth and Planetary Science Letters,Vol. 27, pp. 177–180.Oyawoye, M. O. (1964): The Geology ofthe Nigerian Basement complex. Jour.Min Geology, Vol. 1, 87–102.Oyinloye, O. A. (1997): Physical andChemical Characteristics of the residualclay deposit in Ijero-Ekiti areaof Ekiti State, Nigeria: Implication forIndustrial application. Jour. of TechnoScience, Vol. 1, No. 6., pp. 40–45.Oyinloye, O. A. (2006): Metallogenesisof the Lode Gold deposit in Ileshaarea of Southwestern Nigeria: Infrencefrom Lead Isotope systematic,Pak. Jour. Sci. Ind. Res., Vol. 49, No.1, pp. 1–11.Rahaman, M. A., (1976): Review of theBasement geology of SouthwesternNigeria in Geology of Nigeria (C.A.Kogbe. Ed): Elizabethan pub. Co., Lagos,pp. 41–58.Rahaman, M. A. (1988): Recent advancesin the study of the basement complexof Nigeria. In Precambrian Geol. ofNigeria, (Eds Oluyide et al), a publicationof Geol. Surv. Nigeria, pp 11–41.Rahaman, M. A., Ajayi, T. R., Oshin, I. O.& Asubiojo, F. O. (1988): Trace elementgeochemistry and geotechtonicsetting of Ile-Ife schist belts. Prec.Geol. of Nigeria, GSN pub. Kaduna,pp 241–256.Russ, W. (1957):The geology of Northernparts of Nigeria, Zaria and SokotoProvinces, GSN Bull, pp. 27–42.Truswell, J. F. & Cope, R. N. (1963): Thegeology of parts of Niger and Zariaprovinces, Northern Nigeria: Bulletin,GSN,Vol. 29, pp. 52.Turner, D. G. (1983): Upper ProterozoicSchist Belts in The Nigerian Sectorof The Pan-African Province of WestAfrica, Precambrian Res., Vol. 21,55–79.RMZ-M&G 2012, 59

RMZ – Materials and Geoenvironment, Vol. 59, No. 4, pp. 363–390, 2012363The groundwater potential evaluation at industrial estateOgbomoso, Southwestern NigeriaOcena potenciala podtalnice na industrijskem območjuOgbomoso v jugozahodni NigerijiL. A. Sunmonu 1 , T. A. Adagunodo 1, * , E. R. Olafisoye 1 & O. P. Oladejo 21Ladoke Akintola University of Technology, Department of Pure and AppliedPhysics, P. M. B. 4000, Ogbomoso, Oyo State, Nigeria2Emmanuel Alayande College of Education, Department of Physics, Oyo, OyoState, Nigeria*Corresponding author. E-mail: taadagunodo@yahoo.comReceived: August 20, 2012 Accepted: November 4, 2012Abstract: Vertical Electrical Sounding method was used to map OyoState industrial estate Ogbomoso with a view to determining thegroundwater potential of the study area. Ten Vertical ElectricalSoundings (VES) were carried out across the area using theschlumberger electrode array configuration with current electrodeseparation (AB) varying from 130 m to 200 m. Nine outof the ten modeled curves were H-type where the remaining onewas KH-type. The geoelectric sections obtained from the soundingcurves revealed 3-layer and 4-layer earth models respectively.The models showed the subsurface layers categorizedinto the topsoil, weathered/clay, fractured layers and the freshbedrock. The weathered basement and fractured basement arethe aquifer types delineated for the area. Groundwater potentialevaluated from the maps (i.e. overburden thickness, anisotropiccoefficient, weathered layer isothickness, weathered layer isoresistivity,transverse resistance and bedrock relief maps) revealedthat the Southern and Eastern parts of the study area are the mostpromising region for borehole development. However, Northeasternregion of the study area can also be considered as fair forborehole development.Original scientific paper

364 Sunmonu, L. A., Adagunodo, T. A., Olafisoye, E. R., Oladejo, O. P.Izvleček: Z metodo vertikalnega električnega sondiranja so kartiraliindustrijsko območje države Oyo Ogmoboso v Nigeriji z namenomopredeliti potencial podtalnice. Opravili so sedem vertikalnihelektričnih sondiranj (VES) s Schlumbergerjevo razporeditvijoelektrod in razdaljami med tokovnima elektrodama (AB)od 130 m do 200 m. Devet izmed desetih modeliranih krivulj jebilo vrste H, preostala pa vrste KH. Geoelektrični profili, izdelanipo krivuljah sondiranja, razkrivajo triplastne in štiriplastnemodele. Zastopane so plasti vrhnjega nivoja tal, preperine/gline,razpokane kamnine in nepreperele kamnine. Vodonosnikana preiskovanem ozemlju sta v prepereli podlagi in razpokanipodlagi. Potencial podzemne vode, ocenjen po izdelanih kartah(debeline pokrova, koeficienta anizotropnosti, navidezne debelinein navidezne upornosti in reliefa preperinske plasti), kaže,da so najperspektivnejši za vrtanje južni in vzhodni deli raziskovanegaobmočja. Potencial vode v severovzhodnem delu jeocenjen kot povprečen.Key words: vertical electrical sounding, groundwater potential, fracturedbasement, thick overburden, aquifer, industrial estateKljučne besede: vertikalno električno sondiranje, potencial podtalnice,razpokana podlaga, debel pokrov, vodonosnik, industrijskalokacijaIntroductionThe importance of groundwater as asupply source to the socio-economicdevelopment of a country is tremendous.Though, the state water corporationsmake use of some minor riversas a means of water supply to thepopulace especially in the urban areasbut this water is insufficient for domesticuses let alone its availabilityfor industrial uses. Constant supply ofwater cannot be denied in any industrialsettings, as it serves as one of theamenities to be available in industries.Therefore, groundwater has proved itselfto be the only available source ofwater for industrial uses.The use of geophysics for both groundwaterresource mapping and for waterquality evaluations has increased dramaticallyover the years. The VerticalElectrical Soundings (VES) has provedvery popular with groundwater studiesdue to simplicity of the technique.RMZ-M&G 2012, 59

The groundwater potential evaluation at industrial estate Ogbomoso, ...365Groundwater has become immenselyimportant for human water supply inurban and rural areas in developed anddeveloping nations alike (Omosuyi,2010). Using this method, depth andthickness of various subsurface layersand their water yielding capabilitiescan be inferred. Therefore, evaluationof groundwater potential at industrialestate Ogbomoso was done in order toknow the groundwater yielding capabilitiesor groundwater conditions ofthe study area. In basement complex,unweathered basement rocks containnegligible groundwater. Significantaquifers however, develop within theweathered overburden and fracturedbedrock. This research is particularto know feasibility of potable waterborehole in the industrial estate (i.e. toknow the promising areas for groundwaterprospects within the study area).This was done in order to advise thebuilding engineers and the users ofthe estate not to build factories, warehouses or administrative buildings onthe available zones for groundwaterexploration and to know the promisingzones for groundwater exploration inthe study area. However, the groundwaterconditions of industrial estatewhen properly understood could beused as an effective tool in the planningof reliable water borehole in thestudy area.The study area is underlain by Precambrianrocks of the Nigerian BasementComplex where aquifers are both isolatedand compartmentalized. Theserocks in their deformed state posses littleor no primary intergranular porosityand permeability and thus the occurrenceof groundwater is due largely tothe development of secondary porosityand permeability by weathering and/or fracturing of the parent rocks (Acworth,1987; Olorunfemi & Fasuyi,1993; Olayinka et al, 1997). Groundwaterlocalization in this region is controlledby a number of factors whichinclude the parent rock type, the depth,extent and pattern of weathering,thickness of weathered materials, andthe degree, frequency and connectivityof fracturing, fissuring and jointing, aswell as the type and nature of the fillingsin the joint apertures (Oluyide a&Udey, 1965; Bianchi & Snow, 1969;Asseez, 1972; Odusanya, 1989; Esu,1993; Eduvie & Olabode, 2001).Considering the limited characteristicsof the groundwater reservoirs inthe Basement Complex, the full benefitof the aquifer system can only beexploited through a well coordinatedhydrogeophysical and geological investigationprogram of the prospectivearea. Geoelectrical techniques arepowerful tools and play a vital role ingroundwater investigations particularlyin the delineation of the aquiferconfiguration in complex geologicalenvironments. A planned geoelectricalinvestigation is capable of mapping anRMZ-M&G 2012, 59

366 Sunmonu, L. A., Adagunodo, T. A., Olafisoye, E. R., Oladejo, O. P.aquifer system, clay layers, the depthand thickness of aquifers, fissure orfracture location, and qualitatively estimatinglocal groundwater flow (Fitterman& Stewart, 1986; McNeill,1987; Olasehinde, 1989) and has beenadopted in this study. The most commonlyused geophysical technique forgroundwater exploration is electricalresistivity (Mazac et al, 1987) whichis aimed at identifying high conductivityanomalies, normally thought to bedue to deep weathering. Recent developmentsin geoelectrical data acquisitionand interpretation methodologyprovide electrical images of subsurfacefeatures. A properly calibrated electricalimage can be used to infer the aquiferconfiguration: depth, thickness,horizontal and vertical extent of theaquifers. Investigation involving detailgeophysical study for groundwater potentialin the area covered by this studyis presently non-existence. This exigencyinspired this study. Therefore,the primary objective of this study wasto determine the groundwater potentialand to identify suitable sites/locationsfor exploration of groundwater in industrialestate Ogbomoso, SouthwesternNigeria.Site descriptionThe studied area lies within the crystallineBasement Complex of Nigeria(MacDonald & Davies, 2000). It lieswithin latitude 08 0 06 ′ 07.4 ″ and 08 0 06 ′25.4 ″ and longitude 004 0 15 ′ 03.3 ″ and004 0 15 ′ 49.0 ″ . The study area is locatedat the outskirt of Ogbomoso SouthLocal Government and shares boundarywith Surulere Local GovernmentArea along old Oshogbo road. Thestudy area is accessible with networkof roads that surrounds it and veryclose to Aarada market.Hydrogeological settingAccording to MacDonald & Davies(2000) who classified the hydrogeologyof Sub-Saharan Africa into fourprovinces, these are: Precambrianbasement rocks, volcanic rocks, unconsolidatedsediments and consolidatedsedimentary rocks (figure 1a). Thesefour provinces are well represented ineNigeria (figure 1b). The study area islocated on the Precambrian basementrocks of Southwestern Nigeria whichcomprise of crystalline and metamorphicrocks over 550 million years old(MacDonald & Davies, 2000).Unweathered basement rock containsnegligible groundwater. However, significantaquifers develop within theweathered overburden and fracturedbedrock (MacDonald & Davies, 2000;Alagbe, 2005). In the soil zone (topsoil) of Precambrian basement, permeabilityis usually high, but groundwaterdoes not exist throughout the year andRMZ-M&G 2012, 59

The groundwater potential evaluation at industrial estate Ogbomoso, ...367dries out soon after the rains end. Beneaththe soil zone, the rock is oftenhighly weathered and clay rich, thereforepermeability is low. Towards thebase of the weathered zone, near thefresh rock interface, the proportion ofclay significantly reduces. This horizon,which consists of fractured rock,is often permeable, allowing water tomove freely. Wells or boreholes thatpenetrate this horizon can usually providesufficient water for consumption(MacDonald & Davies).Deeper fractures within the basementrocks are also an important sourceof groundwater, particularly wherethe weathered zone is thin or absent.These deep fractures are tectonicallycontrolled and can sometimes providesupplies of up to 1 l/s or even 5 l/s. Thegroundwater resources within the regolithand deeper fracture zones dependon the thickness of the water-bearingzone and the relative depth of the watertable. The deeper the weathering,the more sustainable the groundwater(MacDonald & Davies, 2000).Geological settingRegionally, the Study area lies withinthe South Western parts of the Basementrocks, which is part of the muchlarger Pan-Africa mobile belt that liesin between the West Africa Craton andCongo Craton, suspected to have beensubjected only to a thermotectonicevent (Alagbe, 2005).In general, the southwestern Nigeriacrystalline Basement (figure 1c) can begrouped into three:• The Migmatite-Gneiss Complex:It compose of Migmatite andgneiss of various composition. Relicsof sedimentary rocks such asquartzitic rocks occurring withinthe group with ages ranging fromPan-Africa (600 million years) toLeonian (Russ, 1957).They havebeen metamorphosed in the middleto upper amphibolite facies(Ajibade et al, 1988).• Metasedimentary and MetavolcanicRocks: (This is also knownas Low grade sediment dominatedschist belt) trending N-S which areconsidered to be Upper Proterozoic(Birimian) in age. The Northwesternbasement has well developedschist belts(Green Schist facies)comprising mainly of phyllite,Schist, quartzitic and banded ironformation(BIF).The rocks are consideredto be Upper Proterozoicthat has been infolded into Migmatite-gneisscomplex (Trusswell &Cope, 1963).• The Pan-African Older GraniteSeries: This intrude both into theMigmatite-gneiss-quartzite complexand the Low grade schist belts.They range widely in age and compositionfrom true granite to grano-RMZ-M&G 2012, 59

368 Sunmonu, L. A., Adagunodo, T. A., Olafisoye, E. R., Oladejo, O. P.diorite, adamalite and tonalities.Other rocks associated with it arehighly hypersthenes bearing rockscalled charnokites.Their Rb/Sr ages range between 750million years and 450 million years(Ajibade et al 1988), which are consideredto be ages of emplacement,classify these rocks as strictly belongingto Pan Africa. Notably amongthe granite series are Kusheriki granites(Truswell & Cope, 1963). Theabove three division is largely basedon lithology and does not in anywayreflect the range of Complex field relationshipand structures displayed onthe rocks.Locally, the study area lies withinOgbomoso and is underlain by rocksof the Precambrian complex withQuartzite and Quartz-Schist and UndifferentiatedGneiss and Migma-Figure 1a. The hydrogeological domains of Sub-Saharan Africa (MacDonald &Davies, 2000).RMZ-M&G 2012, 59

The groundwater potential evaluation at industrial estate Ogbomoso, ...369tite (Ajibade et al., 1988). The rockgroups in the area include quartzitesand gneisses (Ajibade et al, 1988).Schistose quartzites with micaceousminerals alternating with quartzofeldsparthicones are also experiencedin the area. The gneisses are the mostdominant rock type. They occur asgranite gneisses and banded gneisseswith coarse to medium grained texture.Noticeable minerals includequartz, feldspar and biotite. Pegmatitesare common as intrusive rocksoccurring as joints and vein fillings(Rahaman, 1976; Ayantunji, 2005).They are coarse grained and weatheredeasily in to clay and sand-sizedparticles, which serve as water-bearinghorizon of the regolith. Structuralfeatures exhibited by these rocks arefoliation, faults, joints and microfoldswhich have implications on groundwateraccumulation and movement(Ayantunji, 2005).Figure 1b. The hydrogeological domains of Nigeria (extracted from MacDonald &Davies, 2000).RMZ-M&G 2012, 59

370 Sunmonu, L. A., Adagunodo, T. A., Olafisoye, E. R., Oladejo, O. P.Figure 1c. Geological map of Nigeria showing the study area. (Modified after Ajibadeet al, 1988).Theory of electrical resistivity inrocksThe foundation of electrical resistivitytheory is the Ohm’s law (Grant &West, 1965) which states that the ratioof potential difference (V) between twoends of a conductor in an electrical circuitto the current (I) flowing throughit is a constant.V = IR (1)Where R is a constant known as resistancemeasured in ohms (Ω).If the conductor is a homogeneous cylinderof length (L) and cross sectionalarea (A), the resistance will be proportionalto the length and inversely proportionalto the area (Duffin, 1979).ρLR = (2)AWhere ρ 2 is the resistivity measured in2πrohm-meter (Ωm).∫∆V= E.dr.The earth’s material is predominantlymade up of Iρsilicate, which are basically∆non-conductors. V =The presence of2πrwater in the pore spaces of the soil andin the ρ rocks = ∆V.enhances 2πrthe conductivityof the earth when an electrical current(I) is passed ∆Vthrough it, thus makingthe rock ρa= a semi-conductor. . GIIf the electrical AB field 2 generated MN 2 by theπ (( ) − ( ) )current is E across the length when aG = 2 2potential difference MN(V) is applied, then2( )the potential difference 2 can be definedρ ρ2ρ3RMZ-M&G 2012, 59

The groundwater potential evaluation at industrial estate Ogbomoso, ...(Evwaraye & Mgbana, 1993) as:V = EL (3)where E is the electric field strengthwith dimension of volt per meter(V/m).If the current electrode is taken to penetratea small hemisphere of radius r,then ρL the area of the hemisphere becomesρLρL A2πr 2 .AASubstituting22πfor E and integrating2rEquation2 πr2πr3 gives:∆V=∆V=∆V= ∫ E.∫∫E.dr.E.dr.dr.(Duffin, 1979) (4)IρρL ∆V= Iρor ∆VI=ρ(5)∆V=2πrA 2πr2πrand ρ = ∆V.2πr2(6)2ρπ=r ρ = ∆V.2πr∆V.2πrSince the ∆earth V is not homogeneous,∆V= ρ ∆VEquation ρ ∆∫a E=. dr.. Ga= V 6 is used to define an apparentresistivity ρ aρa= . GI . GIwhich is the resistivityIρthe ∆Vearth = would ABhave 2 if MN it were 2π (( ABhomogeneous2)− MN ( 2))2π(((GrantAB r(()) (& MN −West, (π − ) ) 1965). ) )G = 2 2 EquationGG6= 2can 2be written MN22 in a general formρ = ∆V.2πr2( MN )as: MN 2(2( )2 )22∆Vρa= ρ1> . Gρ2< ρ3ρ (7)1>ρ1> ρIρ2< ρ32< ρ3where ρ G is a geometrical factor fixed1< ABρ22>ρ MN3< ρ42for ρ a ρ given π ((1< ρ2electrode ) > − ρ (3< ρ4configuration.) )G1=< ρ2> 2ρ3< ρ42MN n−1n−1The Schlumberger 2( n−)1electrode n−1configurationhas been used in this hstudy. In thishin−12n−1hi∑ h∑ hiρihiρiiρ1 i ∑∑ρti=1 i=1 ρiλ = ρt= i=i=1 ρiarrangement, λ = t=n−1icurrent 1 is i=ρ = =injected ρn−1i 2λlinto the1> ρ2 ρ3< ρ4KRMZ-M&G T = K 2012, × R59T= Kσ× RT K= × RT = K× R TT = × Rρ n−1 n−1T= Kσ× R TρT hiρ h ρIρ∆V=2πr371ρ = ∆V.2πranother pair of electrodes. The geometricalfactor ∆Vρ for the schlumberger electrodeconfiguration I is givena= . Gby:AB 2 MN 2π (( ) − ( ) )G = 2 2(8)MN2( )2where AB is the distance between twocurrent ρ1> ρ2electrodes, < ρ3and MN is the distancebetween two potential difference.ρ < ρ > ρ

372 Sunmonu, L. A., Adagunodo, T. A., Olafisoye, E. R., Oladejo, O. P.using the WinResist software (VanderVelpen, 2004). The VES curves generatedgives the thickness and the resistivitiesof different layers. The depthsounding curves were then classifiedaccording to the resistivity contrastsbetween the layers as H, K, A, Q ormultiples thereof, following the classificationby Keller & Frischnecht(1970) and Patra & Nath (1999). Themodeling produced series of curves asshown in figure 3(a–b). Nine out of theten curves were H-type (ρ 1> ρ 2< ρ 3)while the remaining one showed KHtype(ρ 1< ρ 2> ρ 3< ρ 4). Surfer 8 software(Surfer 8, 2002) was further usedon personal computer to produce 3-dimensionalview of Overburden isopachmap, overburden anisotropic coefficientmap, weathered layer isothickness map,weathered layer isoresistivity map,weathered layer transverse resistancemap, and bedrock relief map in orderto evaluate the groundwater potentialof the study area. Surfer 8 program issoftware that helps to produce 2-Dimensionaland 3-Dimensional images.Geoelectric layers parameters was inputinto this software to produce 3-Dimensionalimages of subsurface in order todetermine the groundwater potential ofindustrial estate Ogbomoso.Figure 2. Layout map of Vertical Electrical Sounding stations.RMZ-M&G 2012, 59

The groundwater potential evaluation at industrial estate Ogbomoso, ...373Results and discussionThe presence of groundwater in anyrock presupposes the satisfaction of twofactors: adequate porosity and adequatepermeability. On account of their crystallinenature, the metamorphic and igneousrocks of the Basement Complexsatisfy neither of these requirements.Basement complex rocks are thus consideredto be poor aquifers because oftheir low primary porosity and permeabilitynecessary for groundwater accumulation(Davis & De Weist, 1966).However, secondary porosity and permeabilityimposed on them by fracturing,fissuring, jointing, and weatheringthrough which water percolates makethem favourable for groundwater storage(Omorinbola, 1979).Figure 3(a). The modeled curve for VES 1 to VES 6RMZ-M&G 2012, 59

374 Sunmonu, L. A., Adagunodo, T. A., Olafisoye, E. R., Oladejo, O. P.Figure 3(b). The modeled curve for VES 7 to VES 10.The modeled curves showed threelayers in nine of the VES stations(i.e. VES 1, 2, 3, 4, 5, 6, 7, 9 and 10)and four layers in the remaining one(i. e. VES 8) (figure 3a–b). The resultshowed that 60 % of the VES stationshave thin overburden and fresh basementrocks (i.e. VES 1, 3, 4, 5, 7 and10), 20 % of the VES stations havethick overburden and fresh basementrocks (i.e. VES 8 and 9) while theremaining 20 % of the VES stationshave thick overburden and fracturedbasement rocks (i. e. VES 2 and 6).From the results, VES 2 and 6 arethe best location for groundwaterprospect because of the thick overburdenand fracture in the basement(Wright, 1990; Meju et al., 1999).VES 8 and 9 could be consideredas another location for groundwaterexploration because Benson& Jones (1988) and Lenkey et al.(2005) reported that boreholesshould be sited where the regolithis thickest.Summary of the formation ofthe layer parameters is presentedin table 1 while summary ofclassification of the resistivitysounding curves is presented intable 2.RMZ-M&G 2012, 59

The groundwater potential evaluation at industrial estate Ogbomoso, ...375Table 1. Summary of the formation of layer parameters.LocationVES 1VES 2VES 3VES 4VES 5VES 6VES 7VES 8VES 9VES 10Layer 1 Layer 2 Layer 3 Layer 4ρ 1/(Ω m) h 1/m ρ 2/(Ω m) h 2/m ρ 3/(Ω m) h 3/m ρ 4/(Ω m) h 4/m400.3222.2280.7197.8190.3215.4100.4230.9228.1220.12.62.31.82.24.52.32.03.01.42.3100.790.461.550.286.541.876.0988.430.4100.16.518.87.94.14.817.02.45.518.16.995835.0606.42160.84580.41830.7271.84344.4128.56781.74036.2-------9.0---------14522.8------------Table 2. Classification of the resistivity sounding curves.Curve types Resistivity model Model frequency VES LocationsHKHρ 1> ρ 2< ρ 39ρ 1< ρ 2> ρ 3< ρ 411, 2, 3, 4, 5, 6, 7, 9, 108Total10Groundwater Potential EvaluationThe groundwater potential of a basementcomplex area is determined bya complex inter-relationship betweenthe geology, post emplacement tectonichistory (fractures), weathering processesand depth, nature of the weatheredlayer, groundwater flow pattern,recharge and discharge processes(Olorunfemi et al, 1999). The groundwaterpotential of the study area wasevaluated based on maps (i.e. overburdenthickness, anisotropic coefficient,weathered layer isothickness, weatheredlayer isoresistivity, transverseresistance and bedrock relief maps)generated from the VES interpretationresults. The characteristic geoelectricparameters enabled the groundwaterpotential rating at each VES location.These maps are as presented below.Overburden Thickness Isopach MapThe depth to the basement (overburdenthickness) beneath the sounding stationswere plotted and contoured at 1minterval as shown in figure 4. This wasdone to enable a general view of theaquifer geometry of the surveyed area.The overburden is assumed to includethe topsoil, the lateritic horizon and theclay/weathered rock. The values rangefrom 4.4 m to 21.1 m. Areas with thickoverburden corresponding to basementRMZ-M&G 2012, 59

376 Sunmonu, L. A., Adagunodo, T. A., Olafisoye, E. R., Oladejo, O. P.depression and are known to have highgroundwater potential particularly inthe basement complex area (Wright,1990; Olorunfemi & Okhue, 1992;Meju et al., 1999).The Southern (i. e. VES 6), Northeastern(i. e. VES 8 and VES 9) and Eastern(i. e. VES 2) side of the study areahas thick overburden thickness whilethe Western and Southeastern side ofthe study area showed thin overburdenthickness. The Southern, Northeastern,and the Eastern side of the study areaare the promising locations for groundwaterprospect.Since the yield of a well in the BasementComplex is expected to havea positive correlation with the depthTable 3. Aquifer potential as a function of the depth to bedrock (Olayinka et al., 1997).Overburden Thickness (m)RangeWeighting15 10Figure 4. Overburden thickness isopach mapRMZ-M&G 2012, 59

∆V=∫E.dr.Iρ∆V=2πrThe groundwater potential evaluation at industrial estate Ogbomoso, ...377to ρ = bedrock, ∆V.2πrweights that are directlyproportional to the overburden thicknesshave ∆Vbeen assigned (Olayinka etρa= . Gal., 1997). I These weights range from aminimum of 2.5 for thickness less than5 m to a AB maximum 2 MNof 2π (( ) − ( ) 10 ) for overburdenG = thickness 2 exceeding 2 15 m (table 3).MN2( )Coefficient of Anisotropy 2 of the OverburdenThe ρ1> overburden’s ρ2< ρ3coefficient of anisotropy(λ) was calculated for each VES stationρusing the layer resistivities and thicknesses(Olorunfemi & Okhue,1< ρ2> ρ3< ρ41992);λn−1∑h ρn−1∑i iρti=1 i=1= =n−1ρl2(∑ hi)i=1hiρi(9)where ρ tis the transverse resistance,ρ lis the longitudinal resistance, i isthe summation limit varying from 1to n – 1, h iis the ith layer thicknessand ρ iis the i-th layer resistivity.The λ values were plotted and contoured.This was done in order to knowthe areas that are good for groundwaterprospects. Areas which show ridgeson the map will be promising zonesfor groundwater prospects while areaswhich show depressions on the mapwill not be suitable for groundwaterprospects. The resulting overburdencoefficient of anisotropy map (figure5) shows λ values ranging from 1.0 to1.45 with a mean value of 1.16. Vividly,the Northeastern and to the baseKT = × R = Kσ×ρTR TFigure 5. Overburden anisotropy coefficient map.RMZ-M&G 2012, 59

378 Sunmonu, L. A., Adagunodo, T. A., Olafisoye, E. R., Oladejo, O. P.Table 4. Aquifer potential as a function of overburden anisotropic coefficient.Anisotropy Coefficient (λ)RangeWeighting2 10of the Eastern side of the study areashowed that overburden’s coefficientof anisotropy (λ) is high. Also, somepeaks were observed at Southern to theSouthwestern part of the study area.These areas with peaks are the promisinglocations for groundwater prospect.Olorunfemi et al, (1991) gives themean coefficient of anisotropy of igneousand metamorphic rocks of theBasement Complex of southwesternNigeria as 2.12 and 1.56 respectivelyand that groundwater yields increaselinearly with increase in λ (Olorunfemi& Olorunniwo, 1985; Olorunfemiet al, 1991; Olorunfemi & Okhue,1992). All the values of λ obtained fallwithin the range of areas underlain bymetamorphic rocks in the southwesternNigeria.Since the yield of a well in the BasementComplex is expected to have apositive correlation with the value ofthe overburden anisotropic coefficient,weights, ranging from a minimum of2.5 for λ less than 1 to a maximumof 10 for λ exceeding 2 have been assigned(table 4).Weathered Layer Isothickness MapThe weathered layers as defined inthis work are materials constitutingthe regolith, straddled in between thetopsoil or laterite and fractured or freshbedrock. The thickness of these lithologicalmaterials varies between 2.4 mand 18.8 m. This was determined fromthe layer interpretation of the soundingresults. The weathered layer isopachmap was produced using a contourinterval of 1 m (figure 6). The mapwas produced with a view to observinghow the weathered basement layerconsidered to be the major componentof the aquifer in the study area variedfrom place to place.The weathered layer is seen to bethickest at Eastern, some part of theNortheastern region and Southern partof the study area, groundwater potentialis most prominent here. The Westernand peak of the Southeastern partof the study area showed a very thinweathered layer.RMZ-M&G 2012, 59

The groundwater potential evaluation at industrial estate Ogbomoso, ...379Figure 6. Weathered layer isothickness mapWeathered Layer Isoresistivity MapIn order to have an insight to thegroundwater potentials of the studyarea, an aquifer resistivity map (figure7) was produced from the interpretedVES data results of this work.The resistivity value of the aquifersat each VES site location was plottedand contoured at 5 Ω m. The map wasproduced in order to distinguish highwater-bearing weathered layer fromlow water-bearing ones, and to find outwhether or not the degree of weathering/saturation varies from point topoint in the study area.As shown on the map, the resistivityvalue of the aquifer is highest at theNortheastern (i. e. VES 8 and VES9) part of the study area which fallswithin medium potential condition (table5). However, the Southern part (i.e. VES 6) and the Western part (i. e.VES 4) of the study area showed lowresistivity values. The Southern partmight be the most promising locationfor groundwater prospect because ofthe results from VES curve 6 (Wright,1990; Meju et al., 1999). The Westernpart (i.e. VES 4) could be consideredas another promising area for groundwaterprospect but because of its thinoverburden (Lenkey at al., 2005), thewater present in the aquifer might notbe able to serve the industrial purposesin the time of prolonged dry season.RMZ-M&G 2012, 59

380 Sunmonu, L. A., Adagunodo, T. A., Olafisoye, E. R., Oladejo, O. P.The electrical resistivity of the saprolitelayer overlying the basementis controlled by the parent rock type,climatic factors, as well as the claycontent. A low resistivity of the orderof less than 20 Ω m is indicativeof a clayey regolith (Carruthers &Smith, 1992; Olayinka et al, 1997).This reduces the permeability andthus lowers the aquifer potential.Weights are assigned to the weatheredlayer resistivity values accordingto Wright, (1992). Table 5 summarizedthe optimum aquifer potentialsassociated with the saproliteresistivities.Figure 7. Weathered layer isoresistivity mapTable 5. Aquifer potential as a function of the weathered layer resistivity (modified afterWright, 1992).Weathered Layer Resistivity (Ω m)Range Aquifer Characteristics Weighting300 Negligible potential 2.5RMZ-M&G 2012, 59

The groundwater potential evaluation at industrial estate Ogbomoso, ...ρLAWeathered Layer Transverse Resistance2πrMap2Aquifer transmissivity has been foundto ∆Vbe = a ∫ Every . dr.powerful means of confirmingzones of prolific aquifers. Thisparameter Iρis defined in hydrogeology,∆V=as the 2product πrof aquifers hydraulicconductivity (or permeability) and itsthickness. ρ = ∆V.2πrT = K × h (10)where ∆T Vρ is transmissivity, K is hydraulicconductivity I and h is the thicknessa= . Gof the aquifer (Todd, 1980).AB 2 MN 2π (( ) − ( ) )According G = 2to Maillet, 2 1974 transverseresistance (R T)MN2( of a ) layer as of the Dar-Zarrouk parameters, 2 is defined as:R T= h × ρ (11)Where, ρ1> ρ2h < and ρ3ρ are thickness and resistivityrespectively, of the layer.ρ1< ρ2> ρ3< ρ4The relationship between transmissivity(T) and transverse resistance (R T) isn−1n−1meaningful, simply becausehi∑ hhydraulicconductivity ρti=1 (K) and i=1 resistivity ρiλ = =(ρ)iρi∑n−1have a ρdirect l linear relationship 2 (Niwas)& Singhal, 1981).(∑ hiCombining the twoi=1equations, we haveKT = × RT = Kσ× R T (12)ρThis relationship is suitable for determinationof aquifer transmissivity,as the ratio K/ρ = Kσ is assumed tobe constant in areas with similar geologicsetting and water quality (Niwas& Singhal, 1981; Aderinto, 1986;Onuoha & Mbazi, 1988; Onu, 2003).RMZ-M&G 2012, 59381Thus knowing the value of K for someexisting boreholes and the value of σextracted from the sounding interpretationfor the aquifers at the boreholelocations, the transmissivity of the aquifercan be computed.These established relationships wereutilized with the hydraulic conductivity(K) values of boreholes near Northwesternside (i.e. some metres awayfrom VES 10), near Northeastern side(i. e. some metres away from VES 9),and the other two boreholes were locatedtowards the Southern part of thestudy area (i. e. behind the Civil defenceoffice). The hydraulic conductivity(K) were determined to be (6.62,11.99, 11.42 and 15.54) m/d respectivelyafter pumping test by D’ StrataDrilling Company and the Kσ of thesepoints were found to be 0.097, 0.097,0.1164 and 0.1034 respectively. Anaverage of 0.10344 was used for theentire study area. The transmissivityat each VES station was determinedby multiplying average Kσ with correspondingtransverse resistance, R Tandthe variation of transmissivity acrossthe aquiferous zone of the investigatedarea is shown in figure 8.On a purely empirical basis, it can beadmitted that the transmissivity of anaquifer is directly proportional to itstransverse resistance (Henriet, 1975).Therefore, transverse resistance mapsis used in determination of zones with

382 Sunmonu, L. A., Adagunodo, T. A., Olafisoye, E. R., Oladejo, O. P.high groundwater potential (Toto et al,1983: Braga et al, 2006) and suitablefor drilling wells.The Eastern flank of the study area hastransverse resistance correnspondingto high transmissivity which in turnmeans greater water potential. Also, alittle peak is experienced at the Southernpart of the study area, this locationis another promising area for groundwaterprospect in the study area. However,the Western and the Southeasternflank generally has low transmissivity.On a purely empirical basis, it can beadmitted that the transmissivity of anaquifer is directly proportional to itstransverse resistance (Henriet, 1975;Hadi, 2009). Hence, there exists a lin-Figure 8. Weathered layer transverse resistance map.Table 6. Aquifer potential as a function of the weathered layer transverse resistance.Transverse Resistance (Ω m 2 )RangeWeighting2000 10RMZ-M&G 2012, 59

The groundwater potential evaluation at industrial estate Ogbomoso, ...383ear relationship between groundwaterpotential and the transverse resistanceof an aquifer (Aderinto, 1986). Table6 gives a summary of the variation ofaquifer potential with transverse resistance.Bedrock Relief MapThe bedrock relief map (figure 9) isa contoured map of the bedrock elevationsbeneath all the VES stations.These bedrock elevations were obtainedby subtracting the overburdenthicknesses from the surface elevationsat the VES stations. The bedrockrelief map generated for the locationsshows the subsurface topography ofthe bedrock across the surveyed area.Bedrock relief map helps to see vividlythe suspected areas for groundwaterprospects. Areas with basementdepressions on the map serve as collectingtrough for groundwater whichwill be the best zones for groundwaterprospects. Bedrock relief has beenused by Okhue & Olorunfemi (1991),Olorunfemi & Okhue (1992), Dan–Hassan & Olorunfemi (1999), Olorunfemiet al, (1999) and Bala & Ike(2001) to investigate into groundwaterprospects at Ile- Ife SW, KadunaNorth Central, Akure SW and GusauNW part of Nigeria respectively.Procedures used by them have beenadopted under this subsection in orderto get the promising areas for groundwaterprospects at Industrial EstateOgbomoso SW Nigeria.The map shows series of basementlows/depressions and basementhighs/ridges. Southern, Eastern andNortheastern part (i. e. VES 2, 6, 8and 9) are the designated areas forthe depressions while Northwestern,Western, Southwestern and Southeasternpart (i. e. VES 1, 3, 4, 5 and7) are ridges zones. The depressionzones are noted for thick overburdencover while the basement high/ridgezones are noted for thin overburdencover. Omosuyi & Enikanselu (1999)findings revealed that depressionszone in the basement terrain servesas groundwater collecting troughespecially water dispersed from thebedrock crests. Thus, the zones withbasement depressions are priority areasfor groundwater development inthe study locations.If the bedrock has a low resistivity,a high aquifer potential could beinferred as result of expected highfracture permeability. Bedrock resistivitiesof the study area from figure3a–b are as given below: VES1 = 95835.0 Ω m, VES 2 = 606.4 Ωm, VES 3 = 2160.8 Ω m, VES 4 =4580.4 Ω m, VES 5 = 1830.7 Ω m,VES 6 = 271.8 Ω m, VES 7 = 4344.4Ω m, VES 8 = 14522.8 Ω m, VES 9= 6781.7 Ω m and VES 10 = 4036.2Ω m. The maximum weight of 10 istherefore assigned to cases wherethe resistivity of the bedrock is lessthan 750 Ω m. As the resistivity ofRMZ-M&G 2012, 59

384 Sunmonu, L. A., Adagunodo, T. A., Olafisoye, E. R., Oladejo, O. P.the bedrock increases, there wouldbe a reduction in the influence ofweathering, with a correspondinglowering of the aquifer potential(Olayinka et al, 1997). Table 7gives a summary of the variation ofaquifer potential with bedrock resistivity.Final Groundwater Potential Map ofthe Study AreaFinal groundwater potential map of thestudy area was produced in order todraw the final conclusion from the evaluatedmaps. The weights that have beenassigned in Table 1 – Table 7 were usedto get the weights of Overburden Thick-Figure 9. Bedrock relief map.Table 7. Aquifer potential as a function of bedrock resistivity.Bedrock Resistivity (Ω m)Range Aquifer Characteristics Weighting3000 Little or no weathering of the bedrock; negligible potential 2.5RMZ-M&G 2012, 59

The groundwater potential evaluation at industrial estate Ogbomoso, ...385ness, Anisotropy Coefficient, WeatheredLayer Resistivity, Transverse Resistanceand Bedrock Resistivity of thestudy area.A single weighted average is then determinedfrom the geometric mean of thefive weights to produce the 2-Dimensionalgroundwater potential map of theinvestigated area (figure 10). The mappresents local groundwater prospects ofthe study area which is zoned in to high,medium and low groundwater potentials.Area with colour brown on the map constitutethe low groundwater potentialzone (i. e. VES 1, VES 3, VES 4, VES 5,VES 7 and VES 10) while area with colourblue constitute the high groundwaterpotential zone (i. e. VES 2 and VES6). Medium groundwater potential zoneshare its colour between brown and blue,this is noted at the Northeastern side ofthe study area (I .e. VES 8 and VES 9).The Southern (VES 6) and the Eastern(VES 2) part of the study area are seento have relatively higher groundwaterpotential than the Northeastern (VES8 and VES 9) region of the study area.Southwestern, Southeastern, Western,Northern and Northwestern (i. e. VES 1,VES 3, VES 4, VES 5, VES 7 and VES10) regions are seen to have low groundwaterpotential in the study area. Thesezones with low groundwater potentialwill be good for engineering purposes(i.e. construction of factories).Figure 10. Final groundwater potential map of the study areaRMZ-M&G 2012, 59

386 Sunmonu, L. A., Adagunodo, T. A., Olafisoye, E. R., Oladejo, O. P.ConclusionThough the study area was assignedas an industrial estate, as long as waterstill remains one of our essentialamenities in life, the groundwater potentialevaluation in the industrial estateOgbomoso cannot be overlooked.Ignorantly without carrying out geophysicalsurvey, the building contractormight have decided to build on thepromising areas for groundwater explorationwhich will lead to scarcityof groundwater in the study area. Also,building of factories on promising areasfor groundwater exploration is evendisastrous to the users in the future.The study has been able to highlight theimportance of resistivity method in effectivehydrogeologic characterization andgroundwater exploration. This study hasproved to be quite successful for mappingoutrock types, structural formationsand fractures which would not have beenobserved at the surface. The presence ofweathered layer and fractured basementare key components of aquifer systemand zone of groundwater accumulationin industrial estate, Ogbomoso. A multidimensionalapproach to this study (thatis modeled curves and the maps presentedfor groundwater potential evaluation)has made the study both very qualitativeand quantitative as information missedby any of the methods is revealed by theother and thereby necessitating justifiableconclusions.It can be concluded that the low resistivityand significantly thick weatheredrock/clay and the fractured basementconstitute the aquifer in this area. Resultsfrom this study have revealed thatthe Southern and Eastern parts of thestudy area are the most promising regionfor borehole development. However,Northeastern region of the studyarea can also be considered as fair forborehole development as it has beenshown from Figure 10.It is recommended that detailed workbe done in this industrial estate usingother relevant geophysical methods soas to confirm the fractures predictedand to elucidate the patterns of thefractures.AcknowledgementsThe corresponding author is grateful toMr. E. O. and Mrs. C. J. Adagunodo,Miss T. O. Ayinla, Prof. Bayo Ajulo,and Mrs V. A. Ajulo (nee Adagunodo)for the financial support in the courseof carrying out this research.ReferencesAcworth, R. I. (1987): The developmentof crystalline basement aquifers in atropical environment. Quarterly Journalof Engineering Geology, Vol. 20,265–272.RMZ-M&G 2012, 59

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RMZ – Materials and Geoenvironment, Vol. 59, No. 4, pp. 391–412, 2012391Physicotechnical substantiation of parameters of blastingoperations in deep open pit minesFizikalnotehniška utemeljitev parametrov miniranjav globokih površinskih kopihP. A. Shemetov 1 , I. P. Bibik 1, *1Navoi Mining Metallurgical Combine, Central Mining Board, Administrative building,Zarafshan town, Navoi region, Uzbekistan*Corresponding author. E-mail: I.Bibik@cru.ngmk.uzReceived: March 28, 2012 Accepted: August 28, 2012Abstract: Physicotechnical substantiation of parameters of blasting operationshas been developed giving due consideration to the effect of increasinglycomplicated factors of deep open pit mines of Uzbekistanon efficiency of mining operations, protection of the rock solid andengineering structures from seismic load of bulk blasts, improvingsafety in production and use of emulsion blasting explosives. Therehas been developed an algorithm of calculation of rational elements ofplacing of blasthole BE charge and size composition of broken rocks.Researches have been made to improve formulation of matrix emulsionand emulsification process of feedstock solutions. A procedureof high bench blasting has been developed. A blasting procedure forrocks with different bastards has been developed. A seismically safefor adjacent protected objects method of rock blasting without decreasingrock breaking effect has been recommended. Based on researchesand analysis of risk level of EBE plant for the purpose ofunconditional provision of safe production of EBE a comprehensivesafety. System has been developed for safe operation of the EBE plant.Izvleček: Fizikalnotehniška utemeljitev parametrov miniranja je bila izvedenaob vsestranskem upoštevanju naraščajoče zapletenih razmerv čedalje globljih površinskih kopih v Uzbekistanu in z ozirom naučinkovitost minerskih operacij ter ohranjanje obstojnosti kamninein varnosti tehničnih objektov v razmerah seizmičnih vplivov zaradimasovnega miniranja in glede na zagotavljanje varnosti pri izdelaviOriginal scientific paper

392 Shemetov, P. A., Bibik, I. P.in uporabi emulzijskih minerskih eksplozivov. Razvit je bil algoritemza izračun elementov pri nameščanju eksplozivnih nabojev v minskihvrtinah z ozirom na želeno zdrobljenost dane kamnine. Opravljeneso bile raziskave z namenom izboljšati pripravo matrične emulzijeeksplozivov iz surovinskih raztopin. Razvit je bil postopek miniranjana visokih etažah in dalje, postopek miniranja v kamninah z različnimitrdimi vključki. Predlagana je metoda miniranja, ki je seizmičnovarna za varovane objekte brez zmanjševanja učinkovitosti drobljenjakamnin. Na osnovi raziskav in analize tveganja delovanja proizvodnepostaje za varno pripravo emulzijskih eksplozivov je bil izdelan celovitvarnostni sistem za varno obratovanje take postaje.Key words: deep open pit mines, increasingly complicated factors, efficiencyof mining operations, bulk blasts, parameters of blasting operations.Ključne besede: globoki površinski kopi, čedalje bolj zapletene razmere,učinkovitost rudarjenja, masovno miniranje, parametri miniranjaIntroductionDevelopment of mining industry inUzbekistan is inseparably associatedwith development of mineral depositsby open-pit method. As is known,the considerable part of open pits foropencast mining of minerals has entereda category of “deep” and thetendency still persists. Parameters ofcurrent open pit mines have essentiallyincreased. Large deep Muruntau andKalmakyr open pits located on the territoryof Uzbekistan are in the worldmining practice unique for complexityand novelty of the solved in the courseof their creation and operation scientificand technical problems defined bypeculiarities of mining-and-geologicaland mining-technical conditions ofdeposits development. There are predesignoptions of profitable miningand further development of Muruntauand Kalmakyr open pits to the depth of900–1000 m.Meanwhile, it is known that with increasingdepth of open-cast mining ofore deposits up to the utmost economicallyexpedient level there becomemore sophisticated mining-and-geologicaland mining-technical conditionsof operations, water content andfissuring of rocks increase, influence ofmine depth on ore resistibility to explosiverupture grows, and requirementsto safety of engineering structures installedon deep horizons are raised andetc. In whole, design of parameters ofdrilling and blasting operations (DBO)in deep open pit mines must take intoconsideration physical-mechanical andRMZ-M&G 2012, 59

Physicotechnical substantiation of parameters of blasting operations in deep ...393physicotechnical properties of rockschanging with mining depth, applicableblasting explosives (BE), seismicload of bulk blasts on safety of pitwalls, engineering structures and services,integrity of the ore-hosting solidand mine openings with involvementinto combined open-and-undergroundmining of ores deposited beyond the finalpit boundary near the pit edges andunder the pit bottom, when the openings(adits, inclined shafts and etc.)may be driven from the exhausted areaof the pit.Meanwhile, having analyzed the currentstatus of drilling and blasting systemallowing for regularities of changein the rock solid blastability as excavationdepth of Muruntau and Kalmakyropen pits increases, it has been determinedthat [1] :• known methodology for calculationof blasting parameters for therock solid in deep open pits doesnot fully ensure the required qualityof rock breaking;• there are no criteria of effectivenessof applicable emulsion BEusing low-price components manufacturedin the Republic of Uzbekistan;• known procedures of blasting andbreaking of rock mass are insufficientto increase completeness ofmineral extraction;• known DBO parameters designmethods do not fully meet specifiedcriteria and limitations to ensureprotection of the pit near-edge solidand engineering structures fromseismic load of blasting;• methodology used for calculationof parameters of safe protective pillarbetween open pit bottom and undergroundmine openings underestimatesseismicity of the near zonebeing of great importance duringconcurrent open-and-undergroundmining of deposits;• existing safety systems in productionand application of BE withcontrolled energy in deep open pitsdo not ensure safety of operationsto the full.Thus, assessment of DBO for opencastmining of deposits up to the utmosteconomically expedient level showsthat improvement of effectiveness ofdrilling and blasting system and optimizationof parameters of DBO processesis feasible through:• effectiveness of explosive breakingand displacement of rock mass;• development of formulation withcheaper and more high-energyemulsion BE using ingredientsmanufactured in Uzbekistan, whichcharacteristics suit the broken rockto the full;• development of blasting proceduresenabling to improve quality of rockmass breaking and to enhance completenessof commercial mineralextraction;RMZ-M&G 2012, 59

394 Shemetov, P. A., Bibik, I. P.• development of efficient parametersof DBO ensuring minimizationof seismic load of blasting onthe near-edge solid and engineeringstructures;• development of comprehensivesafety system in production and useof emulsion BE with controlled energy.Materials and methodsDetermination of the basic mechanismof how parameters of blastingand physico-mechanical properties ofthe solid have effect on the intensityof breaking and displacement of rockmasses. The basis for solving the problemof determination of basic mechanismof how the parameters of blastingand physico-mechanical properties ofthe solid have effect on the intensityof breaking and displacement of rockmass is the information about extentof breaking, which is based on takinginto account both physical-mechanicaland mining-technological properties ofrocks and ores in light of block structureand fissuring of the solid.Experimental dependences developedfor conditions of Muruntau and Kalmakyrdeep open pits demonstrate thatchange in size of natural jointing inthe rock solid with increase of depth isexpressed by the following correlatingequation:D i= 0.306 + 0.0036Н (1)where Н – depth of occurrence of thestratum under study (m).Results of researches have shownthat rocks of Muruntau and Kalmakyropen pits can be grouped and classifiedby four categories of rocks interms of block structure and extentof fissuring: small-block, mediumblock,large-block, highly-large-blockrocks, coinciding with categories ofblastability. Given that in calculationsof DBO parameters the block structureis characterized by the average(weighted average) size of the jointing(block) in the solid, there havebeen developed a methodology andalgorithm of calculation of size compositionof broken rocks based on theeconomic-mathematical descriptionof block structure of the solid and onIBWC classification. In accordancewith the classification the curves havebeen defined, i.e. the lines delimitingthe solids (massifs) of rocks ofdeep open pits by fissuring categorieswhich are generally described by theequation [2] :R iм= 100⋅exp2 λ[ − 3⋅k ⋅ D i ] ,% (2)λ[ ] ,%2where R i - = content 100⋅expof −blocks 3⋅k ⋅with D sizeмof more than 0.667iλ =D i; k – empirical factorcharacterizing ( k + 0.05) the + average 2 size of thejointing D ave(s)in 0.667λ =the solid; l - empiricalcoefficient characterizing fissuring(block structure)0.5( k + 0.05) + 2of the solid:k =1.05+D ave ( s )D ave ( s)k =1.05+D ave ( s)0.5D aveRMZ-M&G 2012, 59( s )0 .667 0. 35

2Physicotechnical substantiation λR 100 exp 3 D of parameters of blasting operations in deep ...i = ⋅ − ⋅ k ⋅мi= K[ 3n 3952 λR i = 1000.667⋅exp− 3⋅k ⋅ Dмiin the Republic of Uzbekistan, µ nU whichλ = (3)n= 2K−[ 3 Q / R]energy and detonation characteristics( k + 0.05) + 21−µsuit physicotechnical properties of0.667µBetween λ = the empirical factor k and average( value k + 0.5 0.05) of the + jointing 2Uhard rocks to the nfuller = 2 −extent.in the solidadm .≥ U1х− µtherek =is 1.05 the + following D ave ( s ) dependence:2 λThere has been developed a procedureD ave ( s)R22λfor determination U i⋅0.5σ[ ⋅⋅] iof adm . throw ≥U[ i = 100⋅exp[ − 3⋅k ⋅ D ] ,%м λ]inρ ⋅coefficientС р⋅U R х adm.k i = 100⋅exp− 3⋅k ⋅ D ,%U = K[ мin(4) during rock U /1.05+Ddisplacement by explosion0.667ave[ = K[ 3 Q] 3 Q / R]2 λR / R]( s )i = 100⋅exp− 3⋅k ⋅ D ,%мiDU = K[of blasthole charges under conditionsλ = 1+ave ( s)0.35k = 0.667σ1,05+D k + 0.05ave of deep open pit t adm .= ρ ⋅ С µ( s )3mines ≥ Kt depending ⋅lg R р⋅U , c adm.0.667 λ = n µ = 2 − onUsing λ = dependences (2) (3) (4) it is0.667 ( k + 0.05) D ave + ( s)0.352 specific 0.667 n = 2 − 1−µBE consumption, blasthole angletowards the sky line, stope 6width0,4possible λ = ( 1 k+ 0.05) + 2to determine k a =λ = 1 − µn = 2 −distribution 1,05+Dof jointings qk( 0.4sin2 +for0.05various rocks in wide )(ave ( s )( k + 0.05) + 2 t3 ≥ K3.72t⋅lg⋅10 R,cαc+ 0.65 D ⋅ Qave ( s0.5) −and 0.016 bench mheight. )As = Ua result of statisticalmanipulation adm .K . range thr=0.5adm .≥ U х1.75of 0.5 fissuring, particularly k =U3 for Muruntau0.01 Ah + q≥ Uof ххpilot work findings,by this procedure the followingqD ficient ( aveR ⋅ Cp⋅ ρ1.05+D 6 0,4 Uk =1.05open ave pit ( s ) with correlation coef-0.5 3.7210 ⋅ Q adm .≥( s )+0.4sin2αDave( s ))( m)K D ave + ( s)c0.65 0.5 − 0.016avek = U = σthr= r ((s)c= s)1.05+D0.71–0.84:formula for σcalculation . ⋅р of ⋅1.753adm .= ρ ⋅ Сadm .= ρ ⋅ Ср throw coefficientduring displacement W WσHуCtgα+ C 0.01 Ah + qR⋅Uр⋅U adm.( s )Daveadm.ave ( s)⋅ Cp⋅ ρbof rock by adm .=D =0.667 0.351 03explosion of blasthole BE charges withК0.667 λ = 1+fK0.35 k =− ≥ F1,05+Dλ = 1+e k =( s )ave correlation coefficient Vt 10.94 V,0H± 0.012 hasуCtgα+ Ck1,05+ 0.05avet( s )DbD =k + 0.05ave0.6673≥ K+t( s )3≥ KWt⋅lg R0.35t⋅lg R,c,DD 1W0aveλ ave = 1(s)+ k =, c((ss))been derived: −1,05+Dk + 0.05ave ≥ Ft( s )D 3≥ KК355 fK(5)V aveV(s)6 0,4e1 63.720⋅0,410 ⋅ Qq( 0.4sin2α4/3c+ 0.65)( 0.5 − 0.016m⋅⋅Given K f= the foregoing, ,3.72 ) U⋅10 =q( 0.4sin2αK ⎡cthere has been3⋅ Q ⎛ V0⎞ ⎛ V04c thr + = 0.65)( 0.5 − 0.016m)1.753 U =0.1σσ= − ⋅ ⎢ −developed an algorithm comof calculation⋅⋅ ⎢⎜⎟⎜рК3.K thr=0.01 Ah + q( 0.4sin2355 0.01 Ah + qR α 1.75c+ 0.65 ⋅ )(R8C0.5p⋅−⋅ρ0.016Cp⋅ ρm)U =K thr=of rational elements of placing of blastholeQ⎣⎝V1⎠ ⎝ V34/3 1K f= ,0.01 Ah3+ q ⎡R⎛ V0⎞ ⎛ V04V BE 0.1 charge σ and size composition(6)=com Hσ ⎢of broken K⎜⎟⎜р= − ⋅ К −уCtgα+ CbW1 уBErocks. Use b of the algorithm8W0HQσ σ σV01 +2 +⎢3⎣⎝ V1⎠ ⎝ V1уCtgα+ CbD =W W0− ≥ F1D =has Q enabled 3to fdetermine aК3HуCtgα+ C−b ≥ FW3mechanismfKVe where α с- blasthole 1Vangle 0 towardsVeЕof effect =КK fKD =1V V−e1BE of DBO parameters, physicotechnicalthe sky line ( o 0К3fK ); m – thickness of hardQσ σ σV0∆1 + 2 +Ve13a properties of rocks and BE seams (m); А – stope width (m); h –K∆=554/34explosive ∆ 55characteristics K on efficiency bench height (m); q – specific ЕBE [{ 1con-sumption (kg/m 00+ ( 1−2μ)4Krσ f,р =−⋅of f breaking = and displacement of rocks4∆,f= ,⎡3 ⎡4/3⎛V⎤0⎞ ⎛4V⎤0⎞4 0.1σ553 ). 3 σ ⎛ V⋅р⎞ ⎢0⎛ V4 a[⎞com10+ ( 1−2during K∆= 0.1σK σ = − ⋅ ⎢ − ⎥blastingcomin deep open pit mines. f=∆⎜3 ⎟1[{⎜1+( ⎟р, К⎜⎟⎜⎟р= − ⋅ К − ⎥8 ⎢4 0.1σ811−2μ)At the samer Qtime, improvement of Specific BE consumptionσcanКbe re-ad = , mр = ⎢⎣−⎝V1⋅⎠⎣⎝V1⎠ ⎝ V1⋅ ⎝ V1⎠ ⎥σ ⎠= ⎥com⎦ р⎦−QVU8С р ρQ[ (blasting 1+1−2V=efficiency and enhancement garded as an integral characteristicKqH= KBEуσ =BEQofBEQ σVQmining Qsafety and decrease in expensesreflectingV1 + σ 2 + σ30K σcompressive σσresistance q of0 aV1 + 2 +BE30d=by 7–8, m=qH% are being achieved rock Q and size of an averageUЕ⋅ Сfragmentр ρ σV01 + σуЕσ =by application 1.13of H emulsion q ∆ BE using (lump) of rock in a shotpile of brokeninexpensive β = arctga ingredients ,deg manufactured ree;12,5q∆⋅С⋅{[1+( 1−ЕaK =rock mass. As a result of processingр8/3a∆ofK=deγU = 3∆∆∆o8/3ra 3 [ ( ⋅∆r 1.13HqK ={{[ 1+( 1−2μ)⋅ ε]σ р = −1+ ⋅ К1⋅−⋅⋅ [ 2μ) ⋅(ε1] − 2μ −1}r∆ σ р = − ⋅ К ⋅ 8RMZ-M&G β = arctg2012, 59 ,deg ree;∆ 812,5⋅С [ 1р⋅+{[ ( 1−+ 2⋅(μ1)]rUo= [ 1+( 1−2μ)⋅ εσ ] 4 ⋅ εр = −deQπ ⋅γ[ ] ,%[ ] ,%γ Qa = , mU Q / R]U ⋅ С[ 1+( 1−ρ0.2282μ

k =1.05+Dλ = 1+k =( s )396 Shemetov,Dave 0.5P. ( A., 1,05 ) Bibik, + D ( I. s ) P.k + 0.05 ave k s=D 1.05 ave+ D ave Dave( s)ave ( s)statistical data and experimental andindustrial blasts the following designformula has been derived:q/(kg/m 3 ) = (0.01 – К аσ comln d ave) (7)where К а– coefficient of adaptation tocertain open pit conditions, К а= 0.0034for Muruntau open pit and К а= 0.0036for Kalmakyr open pit; σ com- compressiveresistance of rock (MPа); d ave- averagesize of rock fragment (lump) in ashotpile (m).0.6670.50.35( = 1+)( k = )bench height q 0.4sin2 (m); α– bench slope ( o );c+ 0.65 0.5 − 0.016mСK b thr – = distance between blasthole k + 0.050.667 1,3 axis0.01λAh= 1+ Dqav kand bench crest (m); К f- coefficient k + 0.05of adaptation of blasthole BE chargeq(0.4sin2αc+ 0.65diameter HуCtgto αmining + CK b thrand = technologicalD =q(0.4sin2 3characteristics of broken rock and 0.01 Ah αcK3conditionsКfof Kthr=charge e initiation by nonelectrictriggering system0.(NTS),K f=550.1σК e= К BE· К Δ- BErelative energy concentration factor,for power industrial BEAchieving the required quality of rock55Q with highVKloosening by blasting under conditions charging = Kf= ,BEdensity К e> 1.0, 4 for reducedpowerQ0.1σ55KVf= com ,of reducing width of blocks blasted in0industrial BE with low charging 4 0.1σcomdeep open pits solely by adjusting the2 λRspecific i = 100consumption ⋅exp[ − 3⋅k ⋅ Dof ] BE ,%мinis practicallyimpossible, since spatial placing Kdensity К eU < 1.0; K[ 3 QV∆ = Q / R]– energya= KBE∆=Q QVV0∆= KBEof blasthole charges have a considerableλ = effect on results of blast. Moreover, Q Vconversionr0.667factor of µ the Qapplied V0BE;, Q _ Vоenergy n = 2 −of the applied BE andthe main ( k + initial 0.05) parameter + 21 − µ ∆ais a blasthole Q K∆=adiameter determining the zone of controlledbreaking of rocks by blasting. Uу0.5adm .the d= , mreference BE (kJ/kg); ∆ ∆arqHK∆=≥ U х∆rk As = a result,1.05+D avedesign formulas have been - conversion factor of charging Q density;( s )determined D ave ( s)for a blasthole diameter and Δ a, Δ r- charging σ density of the appliedadm .= aρ d ⋅ С=р⋅U , m1.13Hq adm.for interrelated with it other parameters BE β = and arctg the reference ,deg BE. ree qH Qad ; = у , mof charge 0.667 placing: lines of the 0.35 least resistanceλ = 1+of rock to blast, k = size 1,05 of + Dblast-There have been determined changesdeγ qHу( s )hole BEkcharge + 0.05avet3 ≥ Kt ⋅lg R,cabove the Dbench ave ( s)toe, of resistance along the bench 1.13 toe Hdur-ing explosionqextent of sub-drilling and unchargedπ ⋅γβ = arctg ,deg ree;2dof blasthole BE chargee− 6 0,4part of qblasthole ( 0.4sin2(plug), α + spacing )( betweenK thr− from mits ) effective3.722cd 1.13eγ H qlength⋅10above⋅ β Q=arctg ,dbenchc0.65 0.5 0.016 Uq=deγ=Н =1.75,mblastholes in a row3and between toe:0.01 Ah + q2 ⋅ ctgαR ⋅ C ρthe rows of blastholes:W/m = 0.387е 0.3 p⋅l efπ ⋅γ(9)2de− 2cwhere l ef– effective length of blasthole q π ⋅γHуCtgα+ Cbcharge above Wbench bast WНtoe = 2d(m). bast e , m−2c1 0D =σ, m (8)t= 2 − 2 ≥σFtD 1К30− +hrhrfKдD2 ⋅ ctgαqН =, meAdjustmentV1σof spatialVt 0 σt arrangement2 ⋅ ctgαwhere D – blasthole diameter (m); Н у– of blasthole charges with specific bast BE bastnσtσt55D = 24/32 4K f= ,∑lдD0 − bast +оп 3 RMZ-M&G ⎡hr⎛ V ⎞ 2012, ⎛ 59 ⎞ ⎤hriσ0 t Vσt σ0 t4i=10.1σσ = − ⋅ ⎢ − ⎥coml ⎜⎟⎜⎟р( КDд= − 1.5...5. 0) д= D0 2 − 2hrd8adhole⎢⎝V дn1 ⎠ ⎝ Vσt1 ⎠ ⎥4com,0.667λ0D =( s )HуCtgα+ CbHК3 уCtgα+ CD f=KeК3Kfeb0

⎢⎣⎝ 11⎠⎝⎠⎥⎦QV = KBEPhysicotechnical Qsubstantiation of parameters of blasting operations σ in deep ...V1 + σ 2 + σ30Е397consumption ∆ is made by alignment of a blasthole shortens by 32 % and 27 %,aspacing K =8/3∆ between blastholes that at а = specific energy consumption 3 {[ 1+decreases ( 1−2μ)⋅ ε]−1∆rσb is determined by the formula: by 26–30 %. р = − ⋅ К ⋅In this 8 regard, abatement[ 1+( 1−2μ)⋅ ε] 4of extent of effective utilization of explosiveenergy of blasthole charge forQad = , m(10)U ⋅ Сbreaking and expansion of р ρqHzone of uncontrolledbreaking is qapparent. For theуσ =where а d– adjusted spacing between purpose of neutralizing these negativeblastholes 1.13 (m); HQ – qBE weight in blastholeβ = arctg (kg). ,deg ree;pensate the shortening 12,5 ⋅Сof рcharge ⋅{[ 1+( 1col-− 2μ)⋅εo]factors it has been proposed to com-deγUo=umn length by using a combination of4[ 1+( 1−2μ)⋅εo] ⋅Blasting operations conducted in Muruntaublasthole emulsion BE charge +ANFOdeep open pit in accordance and by inverse initiation by blastholeπ ⋅γwith the developed procedure in view detonator of non-electric0.2282dtriggeringe− 2c1380⋅Q⋅[ 1+( 1−2μ)⋅εo]of changing qphysico-mechanical propertiesof the solid with increase in the mary pre-breaking C of the solid {[ mass ( is ) ]system (NTS), R = during which the pri-Н =, m0.856 0.28632 ⋅ ctgαpρ 1+1−2μ ⋅εo−pit excavation depth have shown evenerdone by high brisant emulsion BE, andbreaking of the solid at reducing BE final phase of breaking - by low brisantcosts by 12 %. bastbastBE, i.e. by ΣANFO. ( Bn+ PIn n)σsuch case, latertσt= 6,5D д= D0 2 − 2 + 1hrhrignition of ANFO locks up explosionSubstantiationσtof DBO parametersσnt usingemulsion BE providing improve-in charge Lchamber STEM and accordinglyproducts thus extending their duration-1,8nment of effectiveness and safety of facilitating the improvement of effectiveutilization of explosion energy forblasting ∑lопoperations. i Due to the facti=1lthat д= in Muruntau − ( 1.5...5. and 0) dKalmakyr adhole open breaking and working of bench toe. Pilotworks have recorded that applica-дpits onlynin-house produced blastingexplosives are being used, all regulations,tion of combined charge structure imicalnormative documents and analytprovesits explosive force as compareddependences characterizing design to single charge structure by 15 %,values of specific BE consumption and at the same time displacement of oreDBO parameters have been amended boundary and host rock decreases asso as to take into consideration relative much as 1.5–2.0 times, rock breakingexplosive force of the applied BE in relationquality improves with simultaneousto the reference BE (Grammonit reduction of BE costs by 20 %.79/21), which analysis has shown thatat emulsion BE efficiency factors equal For the purpose of improvement ofto 1.05 (Nobelit 2030) and 1.07 (NobelanEBE and WEBE application efficiency2080) the charge column length in and reduction of cost price ofexplo-RMZ-M&G 2012, 59

398 Shemetov, P. A., Bibik, I. P.sive rupture of rocks in deep open-pitmines, researches have been made toimprove formulation of matrix emulsionand emulsification process offeedstock solutions aimed at possibilityto use inexpensive raw ingredientsmade in Uzbekistan. Assessment ofemulsion physical stability using varioussamples of emulsifiers has demonstratedthat cost of ingredients, theirmarket availability and acceptanceanalytical test of raw ingredients ormanufacturers’ guarantee of conformitywith quality standards and technicalrequirements of process proceduremust be the criteria for selection of ingredientsfor oil fraction used for productionof emulsion at the EBE plant.With the view of reducing expendituresfor purchase of raw ingredients andexpendable materials some researcheshave been conducted to optimize formulationand manufacturing methodof emulsion explosive formulations(EEF) which made it possible to reducepercentage of imported raw ingredientsfrom 5.2 % to 4.5–4.0 % and to modernizeequipment and instrumentationin manufacturing scheme of the EBEplant, thus enhancing efficiency andsafety of EBE production.As for priorities for further work onimprovement of formulation for EBEproduction, there have been offeredEEF where calcium nitrate is used toincrease explosion energy, and carbamideinhibiting interaction of EEFand sulphide rock is added into oxidantssolution, in case of lack of sulphidesin rock it can be replaced withammonium nitrate. It is recommendedto avoid application of wax, paraffin,acetic acid, sodium nitrite, sodium lyesolution, thiourea, Swedish porousnitre which should be replaced withpetrolatum, microspheres or foamedpolystyrene. According to economicestimation, the EBE produced by therecommended formulation costs by10–25 % less as compared to similarenergy characteristics. Cost of 1 tof matrix in terms of raw ingredientsis reduced by USD 130 for machineaidedcharging and by USD 78–96 forcartridged EBE. For improvement ofefficiency and safety of EBE productionthe sections such as liquid ammoniumnitrate intake section, cartridgecooling section, oil solution makeupsection and etc. have been modernizedand reconstructed based on performedpilot works.As a result of research works the DBOparameters have been determined toprovide optimal placement of EBEcharge in the solid mass, basic valuesof blasthole network size dependingon used drilling tool and potential oftheir applicability. Thus, for hard-toblastore zones in Muruntau open pit:the network size of 6.0 m × 6.0 m isfor 250 mm diameter blastholes; specificBE consumption in dry blastholesRMZ-M&G 2012, 59

Physicotechnical substantiation of parameters of blasting operations in deep ...399is 1.10–1.25 kg/m 3 (Nobelan 2080), inwatered blastholes it is 1.15–1.30 kg/m 3(Nobilit 2030); stemming space lengthis 5–6 m. In the rock area of the openpit mine it is possible to apply the 250mm diam. blasthole network havingsize of 6.5 m × 6.5 m at specific BEconsumption of 0.98–1.05 kg/m 3 andstemming space length of 5.5–6.5 m.The developed parameters of DBOadapted to EBE have enabled to reduceexpenditures for blasting by 15 %with the best handling of the rock solidalong the whole height of the blastedbench.Development of effective blasting techniquesenabling to improve quality ofrock mass breaking and to enhancecompleteness of extraction of commercialmineral. Intensification of geomechanicaleffects with increasing miningdepth has impact on achieving the targetquality of breaking. This imposesfurther requirements to explosive ruptureof rock which are implemented bymeans of new methods and parameters.Researches on quality of rock massbreaking have demonstrated that evenobserving the determined optimal parametersof charge placing in the solidand at increased specific EBE consumption(q): on average for Nobelan1.11 kg/m 3 (maximum value is 1.27kg/m 3 ); and for Nobelit 1.26 kg/m 3(maximum value is 1.59 kg/m 3 ) it isimpossible to avoid yield of oversizeand coarse size. Moreover, at q ≥ 1.15–1.20 kg/m 3 as a result of predominanceof throwing (propellent) effect of anexplosion over rending effect a considerableportion of rock mass is thrownfrom the side of mined-out area (10–20%) on lower horizons or formation ofshotpiles as wide as up to 40 m takesplace. In the first case this results indecrease of quality and amount of ore,and in the second case this causes dropin intensity of mining operations.In this regard, researches have beenconducted to increase duration ofexplosion effect on the upper part ofbench and to enhance stemming efficiency.Specifically, to increase durationof explosion effect on the solidmass and to enhance locking effect itis recommended to use dynamic stemmingconsisting in explosion of BEcharge in an additional short blastholedrilled at 2 m distance off the mainblasthole or explosion of lockingcharge in stemming space of the mainblasthole. NTS was used to initiate BEcharges: in blastholes by nonelectricexplosion initiating device-B (blasthole)with delay of 500 ms; the surfacenetwork was arranged by nonelectricexplosion initiating device-S (surface)with delays of (25, 42 and 67) ms. Onexperimental areas the delays were selectedin such a manner that the lockingcharge was the first to explodeand then the main (primary) chargeexploded. Retardation of the mainRMZ-M&G 2012, 59

у 3 b400 D = f eShemetov, P. A., Bibik, I. P.К3fKecharge relative to locking charge withplacing the latter in the main blastholewas maintained by various length ofshock-wave tubes (SWT) for lowerand upper boosters with their concurrentinitiating by dentonator of surfacenetwork and was about 7 ms at 2000m/s detonation speed in SWT. In orderto delay the primary charge relative tolocking charge in aditional blasthole acombination of retardants rating (25,42 and 67) ms in surface network wasused. As a result, an interval betweenexplosion of the primary charge andlocking charge was between 17–25ms. It has been established that applicationof locking charge in additionalblasthole has increased extent of rocksolid breaking by 8–10 % and reducedspecific BE consumption by 3 %.Application of emulsion explosiveformulations (EEF) with controlledvolume concentration of explosionenergy applicable for charging dryand watered blastholes, together withcombined structure of charges makes itpossible to meet in practice any technologicalchallenges of DBO owing toavailable park of drilling rigs. This circumstancepromotes increasing heightof benches that allows of reducingquantity and length of transport horizons,increasing open pit wall slope,enhancing intensity of mining in deepopen pits. Moreover, engineering andeconomical performance of open pitmining is increasing.D =K f=HуCtgα+ CbHКCtgαK+ C55,A procedure of high bench blasting has4been developed, 55K which main point consistin 4the 0.1 following. σ Rocks are brokenf=0.1σcom ,comby Q a pair of divergent blasthole charges.VSpecifically, = one blasthole in each pairis KBEQVdrilled 0 = K perpendicularly to bench toe,BEand QV0 the second one – towards benchslope ∆with incline to the toe. Verticalaand K∆= inclined blastholes are arrangedain K parallel =∆r∆vertical planes spaced apartby distance ∆r equal to 1–2 diameters ofblasthole Qequivalent in terms of chargeenergyad =to total, mQ charge in a pair of divergentad =qHblastholes.у , m Blasthole angle andlimit benchqHу height are determined bythe following formulas:1.13Hqβ = arctg ,deg ree;1.13 d H qβ = arctgeγ,deg ree;deγ(11)π ⋅γ2de− 2cπq⋅γН = 2de− 2c, m2 ⋅ ctg q αН =, mwhere α,2β⋅–ctganglesαof bench slope andinclination of bast blastholes bastσin cluster; Нtσt– D дbench = D0 height; 2 bast d e−– 2diameter bast + of 1chargehrequivalent = 2in terms throf 2 charge tD energy 1 toдDσt0−σt +hrhrtotal charge in σt a cluster σof t blastholes;q – specificnBE consumption; γ – densityof ∑ncharging lопi BE in a blasthole; c –i=1lsafety ∑berm.lд= оп − ( 1.5...5. 0) diadholeдi=1lд=n− ( 1.5...5. 0) dadholeдEffectiveness n of the developed procedureof high bench blasting hasbeen tested experimentally during reactivationof western wall of Muruntauopen pit mine. An area of the pitRMZ-M&G 2012, 59

Physicotechnical substantiation of parameters of blasting operations in deep ...401wall to be blasted included four 15m benches, which were combined intwo 30 m benches during the experiment.Diameter of blastholes was 250mm. Blastholes network was 7 m × 7m. Specific BE consumption was 0.95kg/m 3 . Charge structure was combined(EBE and ANFO). In a pair ofdivergent blastholes the BE charge wasplaced in vertical and inclined (β = 65 ° )blastholes.Study of size composition of the blastedrock mass by photo-planimetricmethod has shown that average size offragments of rock mass does not exceed22–25 cm (under similar conditionson benches of 15 m height it was27–30 cm.)A wide range of changing mining-andgeologicalproperties of rocks in deepopen pits requires an individual approachduring blasting of rocks withdifferent bastards occurred in less hardhosting rocks. When blasting the solidwith hard interlayers on narrow operatingbenches in a large deep open pit it isnecessary to ensure their proper blastingand formation of compact shotpilethat is uniform by fractional composition.This can be achieved by placingBE in areas of occurrence of bastardsor by increasing duration of explosioneffect. These two approaches arecombined in the developed technologyof blasthole BE air-cushioned chargewith concavity in bottom part of thecharge. In order to raise the charge tothe level of bastards, in the bottom partof the blasthole an air cushion of 1–2 mlength is formed, and to blast the lowerpart of the solid a concavity is madein the bottom part of BE charge. BEcharge is initiated at height of 2/3–3/4of the charge length. An air gap madewith concavity forms a jet which createsa chock wave directed downwardsand sidewards off a blasthole. In turn,stress waves from cumulative (cavity)charge directed upwards produce secondarybreaking (fragmentation) of upperrock. Directing energy of a part ofa BE charge towards bottom of blastholeincreases duration of explosioneffect on the solid and forms two stresswaves having impact on the wholesolid. Conducted researches based onphysical simulation and pilot blastinghave established that more efficientplacement of BE charge is at the depthoff the bastard up to 1/2 its thickness,at the seam thickness of 1.5 m; and at1/3 its thickness at the seam thicknessof less than 1/4 bench; immediately underthe seam or partially in the seamat the seam thickness of more than 1/4bench height.A blasting procedure for rocks withdifferent bastards has been developed,as a result of which the effectivenessof breaking different bastards (hard inclusions)has increased due to takinginto consideration the main propertiesof hosting rocks, bastards and used BERMZ-M&G 2012, 59

V4BEK Q σBEad = ,commQрσV 01 + σ 2 + σ3σ U ⋅ С ρV1 + σ 2 + σ 8 ⎜ ⎟ ⎜ ⎟3 ⎢ р0qHуσ =⎣⎝V1⎠ ⎝ V1H⎠Е⎦уCtgα+ CbW1 W0402 Q55 D =KЕVShemetov, P. A., Bibik, I. P.f=qK,⎡ − 4/3 ≥ F 4⎤4К3∆3 ⎛ V0⎞ ⎛ V0⎞BEa∆aQ0.1σfKK =σ∆=V1 + σ 2 + σ⎢com3⎜⎟1.13Hq ∆and β = arctg is achieved by drilling ,deg reeadditional; and incomplete charging to {[ the same ( 3 ⎜⎟р= − ⋅ КVe1V0− ⎥[{ 1+( 1−08812,5 ⋅Сσ 8/3∆r3 {[ 1+( ⎢1− 2μ)= ⋅ ε−] ⋅−⋅ 1+1К 1⋅}∆р rσ р = − ⋅ К ⋅Е⎣⎝V1⎠ ⎝ V1⎠ ⎥)⎦р 8 2μ ⋅εo]Qblastholes to dmain e holes γ55Uinside bastard length up to8 =[1obastard ceiling [ ( eliminates) ] 4) ] + 4/3V =4∆KK 1+1−2μ⋅ εaBEcontour K with placing BE Q2μ ⋅εo⋅(1Qf= ,3 ⎡⎛V0⎛Q48/3V∆a 0.1 charges in orientation of explosion action towardsd= σσ1 + σ 2, m3+3 {[ 1+( 1U−⎢⋅ С)] ρ }0com2μ⋅рd= them , ∆ε −1inside mrbastards. Selection qH of BE hosting rock Uσ р ⋅having С=lesser resistibilityfor chargingπ ⋅2dadditionalγуЕ− ρ⋅К ⋅σ =⎢⎟ ⎞ Vσ⎜⎜р= − ⋅ К −8рqHуc blastholes is to blasting. σ = 8 (⎣⎝V1⎠[0.2282e− 21380⋅Q⋅[ 1+( 1−q) ])4 ⎝ V1+1−2μ⋅ ε∆ QV2μ ⋅εo]made byavalue q of detonation velocityНR =qK == KBE8/3∆determined by the , m0.856 0.2863∆ Q , m2 ⋅ ctgαfollowing 1.13Hcorrelation:1.13HqHуqβ = arctg ,degruntau ree;р = − ⋅ К1 + σq Experimental blasting CU3ρ of rock {[ 1( in 1−Mu-2μ)⋅]8 /pσС{[ 1ρ+ ( 1−2μ)⋅ ε]−1}Vrσ o−⋅р2 + σ3012,5⋅С8/3open pit by bastards using theр⋅{[+arctg ,deg ree;deγ 12,5 ⋅С8⋅{ [ 1+U( Ер q 1[ −1o= + 2μ( 1)−⋅ε2μ]) ⋅ ε] −4o⋅deγdeveloped Uo=Q ∆technology of blasthole BE 4 [ 1+ ( 1aabastbastσair-cushioned Σ(Bcharge n+ [ 1P+n) with( 1−2μconcavity) ⋅εo] ⋅( µ )d= K∆,m=tσU ⋅ С1.13Hq tр6,5ρ 3 [{ 1+( 1−2μ)8Dβ д =arctg DqH02 ∆у −r2 + 1 (12) in its bottom part and method of blastingof rocks ohr,deghrreeσtσπ ⋅ ;σ =γn12,5 σ р ⋅С=−⋅{[ 1⋅+ К( ⋅р1−2μ)⋅εo]0.228π ⋅γdeγ2de t − 2cU = q 8with different bastards 1380[ ⋅1Q+ ( 1−20.2282.28 4 [2de− 2cq1380 -1,8 ⋅Q⋅[ 1+R[ 1( 1=+ −( 12μ−)2μ ⋅ε)]⋅εq Н =, m have shown L STEMeffectiveness of the 0.856 solido o] ⋅(⎛1R == wherenC 0.286{[ 1+⋅(⎜1D ∂− 1.13 aBE , mH0.856 0.286detonation qQ2 ⋅velocity ctgαfor breaking with formation {[ ( of compact ) p 3C ρ 1+1−2μ ⋅ε] } 57charging2 ⋅∑8 /8d= , mβ = arctg lαpo−1⎝оп2diadditional π ⋅γ,deg ree;12,5 ⋅СU⋅{[ 1⋅+С( 1р−ρqHр2μ)⋅εo]c blastholesу(m/s); and uniform by fractional composition2d0.228i=1 e e − 2γU = σ =o 1380⋅Q⋅[ + ( 1−⋅εo]lD д 0= – BE detonation − ( q1.5...5.velocity 0) dadhole for chargingН = main nbastbastΣ(Bn+ Pn)shotpile with R = decreasing specific [ 1+( 1q4−con-t2μ)⋅εo] ⋅(1дbast blastholes bast (m/s); , m0.856 0.2863σt– ul-σsumptiotimate Σ(Bn+ of PBE n) Cby 7–8 ρ %. {[ 1+( 1−2μ)= ⋅ε6,5]8 /σ 2 ⋅ ctgttensile strengthD αo−σpд t = 1.13 D H0 of bastard2 q −rock2 + 1= 2 2 1hrhr= 6,5σtσn0− β π = ⋅γarctg+ ,deg ree;12,5⋅С0.228 р⋅{[1+( 1−22 hrhrt(Pa); σdt – ultimate σne− 2ct tensile d strength of Determination of1380blasting⋅Qoperations⋅[ 1+( 1−2μ)⋅ε]eγUo=oqR =-1,8hosting rock (Pa). bastbastparameters -1,8 Σproviding ( B + Psafety ) Lσ mof STEM[ 1+( 1−2μН =,the nearwallsolid and engineering structuresnL n0.856n0.2863tσtSTEMC = 6,5 {[ ( ) ]8 /n D д= D 2 ⋅02ctgαpρ 1+1−2μ ⋅εo−− 2 l + 1hrопi∑lAdditional blastholes∑hrσ πопti=1are ⋅γσndrilled t to the from seismic load of blasting. It is known 0.228i2i=1 depth of: l dд= e−2( 1.5...5. c 0) d1380⋅Q⋅[1+( 1−-1,8adhole that д= − ( 1.5...5. ) bast d nqduring Lblast loosening of rock thereadhole bastΣ(STEM B + PR)=n nдn n Н = σtσt, m0.856D = are seismic waves of huge = intensity havingimpact on safety of the near-wall sol-дD∑l02 −+ 1C6,5hr 2 ⋅ ctgαhrопiσtσnpρ0.286{[ 1+( 1−2μti=1lд= − ( 1.5...5. 0) dadhole, m (13) id and engineering -1,8 structures [3] .дnL STEMnbastbastΣ(Bn+ Pn)σtσt= 6,5where ∑lопD− mark of bastard bottom Generally accepted criterion of estimationof blast seismic effect is mediumi д= D0 2 − 2 + 1hrhrby depth i=1l of ( main blasholes, σ)t between σntд= − 1.5...5. 0 dadholeд-1,8which a nrespective additional blasthole displacement velocity L(U):STEMis arranged 2 (m);nλ n − number of main100⋅exp[ − 3⋅k ⋅ D ] ,%blasholes, between i∑lопwhich a respective U = K[ 3 Q / R](14)ii=1additional lblasthole д= is −arranged;( 1.5...5. 0) dadholeд0.667 − 100 diameter exp[ 3of additional 2 nλR k D ] ,% blastholes (m). where К – µ soil conditions coefficient;i = ⋅ − ⋅ ⋅мinn– = factor 2 U − = of K[ extent 3 Q / Rof ] seismic wave attenuationcharacterized by the depend-( k + 0.05)Both+incomplete21 − µdrilling of additionalblastholes 0.667 up to bastard bottom toµλency:; µ - Poisson ratio.length of 1.5–5 diameters of blastholesU adm .≥nU=2 −хQ =Kaβ =НD дDl 0д=0.11.05 D ( s )D + aveave(s)σ adm= Uρ ⋅ С р⋅adm .≥ U хn=0.5(k + 0.05) + 21 −k =0.5σ= −µ.U adm.⋅ К⎢⎜⎟− ⎜RMZ-M&G 2012, 59⎟⎥⎥

Physicotechnical substantiation of parameters of blasting operations in deep ...403λ⋅ D i ] ,% Safety of the near-wall solid and engineeringstructures U = K[ will 3 Q / be R]ensured tected objects method of rock blast-n A seismically safe for adjacent pro-,%U = K[ 3 Qn/ R]if deformations of the wall solid and ing without decreasing rock breakingµfoundations of protected n = 2 µ − structures effect has been recommended. As anU caused = K[ 3 by Qexplosion / R]n = 2 −effect do 1 −not µ1 − µextendthe limits of horizontal component tion of seismically safe technology forexample let’s consider an implementa-of vibration µ velocity U adm, whose conducting DBO in Muruntau open pit,.≥ Udependence n = 2 − on U хhorizontal adm .≥ U х distance off where a task of prevention of destructionof five objects located on the pit1−µthe blast point (R) is described by theequality U x/(cm/s) = 450 σ adm .= ρ ⋅ С R-1,85 , and р⋅U σthe adm.wall at the distance of 120 m; 750 m;Uestimate of tolerable vibration velocity 720 m; 480 m; 80 m off centre of the0.35adm .≥ U adm .= ρ ⋅ С р⋅U adm.хk 0.35 = will be:blast block was solved. For this purpose,a block to be blasted has been1,05+D avet( s )3≥ Kt ⋅lg R,c1,05 D ave ave σ(15)( adm s).= ρ ⋅ С р⋅Ut ( s )D +3 adm.≥ Kt ⋅lg R,cave(s)where σ adm.- stress at which a samplechosen on horizon +375 m and a projectfor conducting the DBO within the6 0,4of the open pit rock is not3.72ruptured6 ⋅10,4by⋅ Qc+ 0.65)( 0.5 − 0.016mmultiplet) U =dynamic impacts; ρ - averagezone of adjacent objects with achievingthe design performance of seismic33≥ Kt ⋅lg R,c3.72 ⋅10⋅ Q.65)( 0.5 − 0. 016m)U =1.751.750.01 Ah + qRCp⋅ ρrock density; С р– mean value of velocityof medium 6 displacement 0,4 along theAh + qR ⋅ Cp⋅ ρloads in different directions off the centreof the blasted block has been plot-3.72 ⋅10⋅ Q16m) horizontal U = component on longitudinal1.751W0wave Rfront; ⋅U adm.CW- mass velocity of theted graphically on computer. The blockp⋅1 ρ W0− ≥ F−≥ VFsolid vibrations (displacements) 1 0 takento be blasted is prolate shaped withV1V0as admissible criterion of an estimatenarrowed ends characterized by twoof Wseismic explosion wave impact onparameters – length and width. Given1W0nU = −K[ 3 Q≥/RF]4/34the solid.3 ⎡4/3⎛ V ⎞ 4⎛that ⎞the ⎤ block to be blasted is surrounded−⎜⎟V0V1V00σ3= −⎡⎛ V⋅⎢⎜⎟рК ⎤0⎞ ⎛ V0⎞ by ⎥ several protected objects,µ σ ⎢ 8 ⎢Having set values of distance ⎜between⎟⎣⎝V1⎜⎠ a ⎟р= − ⋅ К −distance ⎝⎥V1 ⎠ ⎥⎦R i(i = 1…. n) to protectedn = 2 −8 ⎢blast point 1−µ⎣⎝V1⎠ ⎝ V1⎠ ⎥and protected object it is objects ⎦ is measured by connecting centreof the block to be blasted with pro-4/34possible 3 ⎡to determine ⎛ V⎤0⎞ seismically ⎛ V0⎞ safeσ ⎢ σ1 + σ 2 + σ3weight of charges ⎜⎟for ⎜instant ⎟р= − ⋅ К − ⎥detonations.In addition, to avoid Е⎠⎥⎦interferenc-the shortest one is chosen. The prolatetected objects. Amongst R idistancesU adm8 ⎢⎣⎝ V1⎠ ⎝ V.≥ U σх1 + σ 2 + σ13Еes of seismic waves it is required that shaped block is oriented with the longdelay intervals (t 3) exceed lifetime {[ of ( side in ) the 8/3σ adm σ σ3 1+1−2μ⋅ ε]line −1}of the nearest protected1 + .=2 +ρ ⋅ С р⋅U adm.38/3σ 3 Кplus phase of seismic waves: р = − {[ 1⋅+ ( ⋅1− 2μ)object ⋅ ε]−R min1}(Figure 1).Е σ 8 [ 1+( 1−2μ)⋅ ε] 4р = − ⋅ К ⋅8t3 ≥ Kt ⋅lg R,c[ 1+((16)1−2μ)⋅ ε] 4After the drilled block has been orientedaccordingly, rows of blastholes8/3where: 3K t– coefficient {[ 1+( 1−2μ)allowing ⋅Uε] ⋅ С−1р} for ρσ К σ =rock р = − ⋅ ⋅ U ⋅ Сhardness,63.72 8 10 KQt [ 10,4 р ρ⋅ ⋅σ= + 0.01–0.03. ( 1−2μ)⋅ ε] 4 in plan view are inclined at an angle16m)qU =qwithin the range from 45 ° to 135 ° to1.75R ⋅ Cp⋅ ρq U ⋅ С ρ8/3, deg ree;RMZ-M&G 2012, р 59σ =12,5 ⋅Ср⋅{ [ 1+( 1−2μ8/3) ⋅εo] −1} ⋅( 1+μ)ree;U12,5=⋅Ср⋅{ [ 1+( 1−2μ)⋅εo] −1} ⋅( 1+μ)qUo=o4[ 1+( 1−2μ4) ⋅ε] ⋅( 1− µ )

404 Shemetov, P. A., Bibik, I. P.where R1 = 120 m; R2 = 750 m; R3 = 720 m; R4 = 480 m, Rmin = 80 m: blasted block-protectedobjects distance; Перегрузочный пункт - Dumping station; Борт карьера - Pit wall; КНК-270 – High-angle conveyor-270; ЦПТ – Cyclic-and-continuous process; ДПП – Crushing-andconveyingplantFigure 1. Orientation of an area of the blasted block relative to some protected objectsTable 1. Results of mathematical modeling of seismic load on protected objects of theopen pitConfigurationSeismic load rateExtent of stability of an objectof blasted block R 1R 2R 3R 4R minR 1R 2R 3R 4R minTrapeze 37.1 21.8 20.7 29.2 37.8 – + + + –Rhomboid (α = 90 ° ) 20.5 12.9 16.1 18.9 26.4 + + + + +Rhomboid (α = 120 ° ) 18.3 10.5 14.2 16.4 24.1 + + + + +the bee-line (the shortest distance) tothe object. Wiring-up of the explosivecircuit is made so that it could lead tosuccessive detonation of charges in thedirection from the chosen protectedobject to centre of the blasted block.Arrangement of blastholes on the chosenblock within the prolate-shapedarea oriented in plan view with narrowedends along the bee-line to thechosen protected object enables, dueto optimal shape of the area and anglesof inclination of blasthole rows in therange of 45–135 ° , to achieve redistributionof released seismic energy bywidth and length of explosion field.Calculated by mathematical modelingrates of seismic load and findings onRMZ-M&G 2012, 59

Physicotechnical substantiation of parameters of blasting operations in deep ...405objects safety in case of trapeze- andrhomboid-shaped blast block at an angleof blasthole rows inclination α =90 ° , α = 120 ° are presented in Table 1.The analysis of the findings shows thatwhen a trapeze configured block isblasted, three protected objects standseismic load and two are destroyed,and when an elongated rhomb configuredblock is blasted, the whole groupof protected objects stand seismic load.It has been established that blastingmethod, including drilling of blastholerows in a block of definite configuration,their charging and short-delayedblasting, in which case the blastholesrows are commuted in a block havingan elongated configuration viewin plan with narrowed opposite ends atan angle of 45 ° ≤ α ≤ 135 ° to a beelineto one of the chosen protected objects,provides reducing seismic load on protectedobjects:• in the direction of commencementof blasting the rows – twice;• to the left and to the right of the explosionfield in 120 ° sectors - fourtimes.Successive detonation of blastholerows with delay from the nearest holein the direction from the protected objectresults in redistribution of releasedseismic energy in such a manner thatthe maximum flow of seismic energyis directed towards the side oppositeto the protected object. This facthas been determined experimentally.When length of rows in the blastholeblock is reduced, a number of blastholerows are increased to maintain the totaltarget weight of blasted BE and a totalnumber of rows, that leads to decreasein extent of seismic load and concurrentincrease in seismic load duration.The two said factors allow of adjustingflow of seismic energy on protectedgroup of objects so that the shock effecton the nearest object could be minimaland the other nearby objects could bepractically safe.Using the open pit space for miningof ore deposits outside the pit contourenables to implement advantagesof combined open-and-undergroundmining method to the full. At thesame time, conventional approach todesign and operation of deep openpits does not take into considerationchanging mining methods in view ofdevelopment of underground mine.In this regard, researches have beenconducted to determine safe parametersof arch pillar separating openand underground mining operations.In calculations it is deemed that rockis the elastoplastic solid medium. Toensure stability of the arch pillar solidit is required that seismic load doesnot cause irreversible deformations.The condition of maintenance of rockstability is written as follows:U ≤ U o(17)RMZ-M&G 2012, 59

thrмR iλ = 2 λ= 100⋅exp[ −( 3 k ⋅ k+0.01 ⋅0.05)D ] 3i ,% Ah + 2+qR ⋅ CnU = K[ 3 Q / R]p⋅ρ1− µ406 nShemetov, P. A., Bibik, I. P.H U K[ 3уCtg=+ CQb/ R]D =Кk αW W .U0.667 0.5µх1 0λ = =n = 2− ≥ F3 1.05 D ( s )( k +f0.05) KeD+avewhere U – ave µ2+V V1− µ( s)1 0velocity of rock displacementcaused 1−µ by explosion (cm/s); U oRupture (breaking) σn = 2 −adm .= ρstress ⋅ С р⋅Ucan adm. be definedas follows:– 55 safe velocity of rock displacementnU 0.667U0.50.35 admK[ 3.≥ U х4/34K k = Q / R]f= λ = 1based on, + k =⎡⎤1.05+Dconditions of their nUelastic deformationadm(20).≥ UU х K[ (cm/s).31,05+D 3 ⎛ V0⎞ ⎛ V0⎞4 0.1σ= k + 0.05avet( s )3≥ Kt ⋅lg R,c( s )Daveave ( s)Q / R]Dcomave ( s)σ ⎢⎜⎟⎜⎟р= −К − ⎥adm .=µ8ρ ⋅ С р⋅U ⎢⎣⎝ V adm.1 ⎠ ⎝ V1⎠ ⎥6 ⎦0,4n = 2 −Q Velocity σ of rock displacement U dependingon charge 1−1,05where K – coefficient depending onadm0.667.= ρ ⋅ С р⋅U adm.µn =q2( 0.4sin2 10.353.72 ⋅10⋅ Q− −αVµc+ 0.65)( 0.5 − 0.016m)λ = K1+ KBE thr= k =U =properties of massif.1.75µ+ Dsize, distances3Q k + 0.05toV0.01 avet( s )σ3 ≥ K1 + σt ⋅lg R,cD Ah + q2 + σ R ⋅ C3p⋅ ρ0ave ( s)protected object U and elastic impedancet Stress on elementary surface insideof 3≥rock Kt can⋅lgbeR,admc.≥ U хЕ6 0,4U expressed by the follow-formula: уCtgα+ Cadm .≥ U∆ Hхthe rigid body acts on both normal andaing3.72 ⋅10⋅ Qq( 0.4sin2αc+ 0.65b)( 0.5 − 0.016m)U = W1 W0K K=8/3∆ thr= D =1.75σ60,4tangent. The body referred to three perpendicularaxes Q x3.72 ⋅10adm .= ρ ⋅ С⋅ Qр⋅U adm.3 {[ 1−+ ( 1−2≥μF3) ⋅ ε]−1}∆r6m) U = σК0.013f adm(18), Q у, Q zis affected.=K Ah + qR ⋅ Cρ ⋅ С р⋅U σ р = − ⋅ КVp⋅ ρe⋅ 1V0adm.8.351.75[ 1+( 1−2μ)⋅ ε] 4R ⋅ Cnρby at least three stress components s 1,U = K[ 3 Q / R]p⋅5+ave ( s )HQt3 ≥ Kt ⋅lg R,cswhereуCtgα+ CQ –bweight of simultaneously 2, s 3causing 6 more components s ху,a(sd ) = , m 55W1 W04/34D = t sblasted charge (kg); R – distance to уz. s xz, s ухand etc. Action of theseave( s )3≥ Kt ⋅lg R,cqHK U ⋅ С ρf= ,− ≥ Fруvery components of stress causes deformationof volume Vprotected W1 Wµσ =3 ⎡⎛V⎤0⎞ ⎛ V ⎞К30fK 4n = 2 −0.1σVe6 0,41V0σ ⎢com0−objected≥ F 3.72 (m); ⋅10C p⋅ Q r – elastic q⎜⎟⎜⎟р= − ⋅ К − ⎥8)( 0.5 − 0. 016m1) − µ⎢impedance ofUrock = 6 0,4(m/s kg/m 3 ).0⎣to ⎝ V1⎠1during ⎝ V1its ⎠ ⎥⎦V1V 3.72 1.750+ qR⋅10⋅⋅ Q.5 − 0. 016mCp⋅ ρ change from r 0to r 1.1.13 55 Q )VHUq=4/341.758/3q β = Karctgf= =USafe adm .≥velocity U, KBE ,deg Rх of rockree;⋅ Cdisplacement p⋅ ρ12,5 3 ⎡⋅⎛Ср⋅{ [ 1( 1−2μ)⋅εo] −1} ⋅(1+QdcaneγUGiven = σV⎤0Vo1 +⎞σ 2 +⎛σV0⎞4 0.1σσthat⎢30com⎜in whole definesvolumetric strain (relative vol-be determined ⎡ from 4/3 general 4conditions⎤of their 3 Wdeformation.⎛ V1 0⎞ W[ 1⎟+ ( 1−⎜2μ⎟р= − ⋅ К − ⎥48 ⎢0⎢ If⎛in V0the⎞⎣⎝V1⎠ Е ⎝ V1⎠)⋅⎥⎦εo] ⋅( 1− µ )σ = −− ⎥course ofadmdeformation ⎜⎢ of volume ⎟⎜⎟р .= ρ ⋅WКС р⋅U adm.− ≥ FQ8 1oto ⎥ volume ume deformation) (e) of the medium⎣⎝VWV∆=a0K π K⋅γ = −11 ⎠ V≥0 F⎝V1⎠8/3BE ∆d⎦0.2282.28Q 2eV 1the specific − 2V∆c1energy V0of volume V oin-K by some R c final and quite definite s 2under σ action 1380⋅Qof total ⋅3[ 1stress + ( 1−{ [ 12μ+tensor )( 1⋅ε−2]μ)⋅ ε]o (s 1, ⎛1−1}Vqr1 + σ 2 + σ3R = σ р = − ⋅ К ⋅0⋅⎜Н = tcreases , s 3), we obtain:3≥t⋅lg , m,0.856 0.2863for σ21 ⋅ ctg + certain σ 2 α + σ4/34CЕ8{[ ( ) [ 1+] ( } 8 / 1−2 0. μ 57 ) ⋅ ε1 1 2μ εo1 ⎝] ρ + − ⋅14+medium 3 3value ⎡⎛F, V this ⎞ forms ⎛ ⎞ ⎤ p∆ Q0V0necessary aЕ and σ6= sufficient −0,4⋅ ⎢ conditions − ⎥6m) for rupture. 3.72 ⋅10Then, ⋅ Q⎜⎟⎜⎟р ⎡ К4/34K = ad = 3,m⎤U =general 8 ⎛ V ⎞⎢ ⎢0⎣⎝V ⎛ V0⎞U ⋅ С ρ8/3∆σ = − ⋅ equation 1 ⎠−⎝ V 3qH{[ 1+( 1−2μ)⋅рε]−1}∆rof 1⎥⎠⎥⎦(21)energy 1.75⎜⎟⎜⎟р у КσbastbastΣ р ( B=−+P⋅К)σ⋅=σRconditions defining 8/3 potential3 ⋅ C 8{[ 1p+ ⋅ ρ ⎢⎥( 1⎣⎝ V1⎠ ⎝ Vn ntσt1D = 2 2⎠ 8дD−12μ)⋅ ε]−} ⎦= 6,5 [ 1+( 1−q2μ)⋅ ε] 40− +σrupture hrр = − of ⋅ Кmedium hrσ ⋅ can be presented astfollows: 8 σ1 + σnQta1.13[ σ1H2+ + ( 1σq−3 2μ)⋅ ε] 4 where-1,8Е – dynamic modulus of elasticity;8/d= , mU ⋅ Сβ = arctgW W σ1 + σ 2 + Еσ,deg ree;3Lр ρ 12,5 ⋅С⋅STEM{[ 1+( 1−2μ)⋅ε]qHрos 1, s 2, s 3– total stress tensor;negativenу1 0 deγσ = Uo=4−(19)l U ⋅ С≥FЕρqvalues of s рconform∑[ 1+( 1−2μ)⋅εo] ⋅(1опрσVi1=V0to 8/3i=1 3compression stress as in this casel (where W 0and {[ 1+( 1−2μ)⋅ ε]−1}д= − 1.5...5. 0σ) dadhole р W=1−д– energy ⋅ К ⋅ of medium 8/3n1.13Hq π ⋅3γdeformations are positive, and positiveεbefore and 2 after rupture 8 {[ 1+( 1(kg m); [ 1−+2μV( 1)−⋅ ε0and 2]μ)⋅− 1] }σdК48/3β = arctg ,deg ree0.228рe = − ⋅−2;12,5 ⋅Сcр⋅{ [ 1+( 1−2μ)⋅εo⋅values of s 1380рconform ⋅Qto ⋅[ ] −1tensile 1+(} ⋅( 1+μ1−2μ)⋅ε])d4/34V 1– volume ⎡ qН 12,5 = ⋅⎛of medium⋅{ [ 1+( 1−before ⎤2μ)⋅εand 8/33 СV8⎞⎛ ⎞ ]afterrupture (m 3 р−1} stress⋅( 1+μas )deformations are negative0, Vm[ 1+( 1−2μ)⋅ ε] 4oeγUo=R =4[ 1+( 0.856 1−2μ0.286) ⋅εo30σoU = − ⋅ ⎢ ). − ⎥ here.o⎜⎟⎜⎟рКC ρ {[ ] ⋅( 1− µ )1+( 1−2μ)⋅ε]8 /2 ⋅ ctgUαo−⋅ С ρp8 ⎢4⎣⎝σV[ 1 + ⎠ ( 1−⎝2μVрπ ⋅γU=⋅ С ρ1)⎠⋅ε⎥⎦o] ⋅( 1− µ )р0.2282.280.2dσ c=qe− 21380⋅Q⋅[ 1+RMZ-M&G( 1−2μ)⋅ε2012, o]59⎛1−µ ⎞qbastqbast R = Σ(Bn+ Pn)⋅⎜⎟Н =σtσ0.57tσ σ σ 0.2282.280.57= 6,51 + D д 2=+ D,032m0.856 0.2863− 2 + 1 C ρ {[ 1+( 1−2μ)⋅ε] }8 / 18/3o−1⎝ + µp⎠2 ⋅ ctgαU adm≥nμµµ2.21

W 8 ⎣⎢⎣⎝ V 1 ⎠ ⎝ V ⎦1W01 ⎠− ≥ F⎥⎦V1V0Physicotechnical σ substantiation of parameters of blasting operations in deep ...4071 + σ 2 + σ3Е4/34Use of 3 ⎡dependence ⎛ V⎤0⎞ (21) ⎛ V0⎞σis8/3of great process, we take into account the effective(working) stress s рimportance ⎢for practice as 8/3besidesrelated togeneral 3⎜{[ +⎟( 1−2⎜μ)⋅⎟р= − ⋅ К − ⎥8 ⎢ε]−1}σ р = −qualitative ⋅ К⎣⎝ V1⋅⎠ ⎝ V1⎠ ⎥dependences ⎦in determinationof parameters [ 1+( 1−2μ)of ⋅ ε] 4rupture elasticity:the known dependence from theory of8σ1 + σ2 +σ3U ⋅ С р ρσ = Е(22)qthat enables to determine safe 8/33 { 1+1−2μ⋅ ε velocity −1of rock displacement U o:8/312,5}σ р = − ⋅ К ⋅2μ8/312,5 8 ⋅Ср⋅{ 1[ 1++ 1( 1−−2μ2μ⋅ ) ε⋅εo] −1} ⋅( 1+μ)U =(23)σoU ⋅ С=where С р– velocity of P-wave propagation(m/s), 1380qС р = 0.228 4000 cm/s; 2μ m - Poisson2.280.2282.28o1380⋅Q⋅[ 1+( 1−2μ)⋅εratio, m 0.856 = 0.25–0.30; 0.286 e о– admissible 3 rela-8 / o]R =2μotive deformation p 0.8560.2863C ρ {[ 1of + rocks ( 1−2μwithin ) ⋅ε] elastic-for conditions of the mine horizons}8 /o−8/312,5 p ⋅С1р⋅ [ 1+( 1−2μ)⋅εo]Uity,o=4+128 m, +78 m and 1+( ±0 1−value 2μ)⋅e ε оis o acceptedΣ(Bwithin + Pthe ) range of⋅ 1n n0.0003–0.0004.R =L-1,8STEMn6,5= 6,5n1380⋅QnL 0.856STEM C pρр0.286Results of calculation of ceiling thickness,Σ(B pillar (protected pillar) are determinedsubject = 6,5 to seismic explosion ef-n+ Pn)fect of n bulk blasting conducted in theopen -1,8 pit based on BE charge weightLper STEM one retardation and are 50 m forMuruntau open pit (Figure 2).Researches have been made on seismicload of huge blasting to determinecritically admissible deformations andvelocities of displacements for surfaceengineering structures and undergroundmine workings. It is recommendedto set an admissible relativeRMZ-M&G 2012, 59[ ( ) ][ ( ) ] 4[ ( 2μ)o41+1−2μ ⋅ε] ⋅( 1− µ)ρo0.570.57{ −1} ( )[ ] ( − µ )⋅[ 1+( 1−2μ)⋅εo]3[ 1+( 1−2μ)⋅ε]8 /−0.228{ 1}o2.280.57Subject0.57to dependences (17), (18)and (23) 0.57we derive an equation for⎛1−µ⎞determination ⋅⎜of required thickness⎟of ⎝1protective + µ ⎠⋅ 1+μpillar over undergroundmine workings at different values ofBE charge weight (Q) per one retardation:⎛1−µ ⎞⋅⎜⎟⎝1+µ ⎠0.57(24)deformation of rock within the elasticitylimits in accordance with classificationof protective structures by theirresponsibility and lifetime.Development of comprehensive safetysystem in production and use of blastingexplosives in deep open pit mines.It is known that main technologicaland operational properties of emulsionBE (EBE) depend on correct selectionof formulation of oxidant, emulsifier,method of emulsion production, natureof sensibilizing additive and EBE manufacturingequipment.

qLevel of average technical (theoretical)risk for EBE manufacturing plant has{[ ( ) ] } (408 1.13HqShemetov, P. A., Bibik, 8/3 I. P.β = arctg ,deg ree;12,5 ⋅Ср⋅ 1+1−2μ ⋅εo−1⋅ 1+μdeγUo=4[ 1+( 1−2μ)⋅εo] ⋅( 1− µ )It has been established that having a been calculated as a sum of criteria ofnumber of advantages over other types probability (theoretical frequency) ofπ ⋅γ0.2282.282dof industrial BE, EBE composition has occurrence (В) and importance of consequencesR = of undesirable events (Р) in ⋅⎜Н =, m0.856 0.2863e− 2c1380⋅Q⋅[ 1+( 1−2μ)⋅εo] ⎛1−µsome q specific features: there is a numberof critical parameters of external effects,which increasing leads to genera-risk level was:terms C of more { serious [ 1+( 1−ctgevents 2μ)⋅ε2 α(n). ]⋅The } 8 / 0. 57o−1⎝1+µpρtion of initial site (of explosion); EBEdecompositionbastrunsbastΣ(Bσat molecular level n+ Pn)tσt= 6,5 points. (25)D д= D0 and 2 requires − 2 no additional + 1hrhr reagents;σEBE tσnis characterized t by high energy Based on results of the assessment-1,8concentration and velocity of energy Lit STEM can be concluded that the total risknoutput, which, as a rule, ends in explosioni having effect on the environment∑lопi=1д= (equipment, − ( 1.5...5.0) dbuildings adholeдand structures,npersonnel). Therefore, production anduse of EBE require strict regulation asper safety requirements [4] .level during operation of EBE plantunder current conditions is acceptablelike for a hazardous industrial objectsubject to observance of technical andorganizational measures (safety system)aimed at risk mitigation. And atthe same time, a source of uncertaintyof risk assessment is the human factorand equipment failure.Figure 2. Ceiling thickness changing from the level of seismic explosion effect forconditions of Muruntau open pitRMZ-M&G 2012, 59

Physicotechnical substantiation of parameters of blasting operations in deep ...409Based on researches and analysis ofrisk level of EBE plant for the purposeof unconditional provision of safe productionof EBE a comprehensive safetysystem has been developed for safeoperation of the EBE plant (Figure 3).In addition to the active (instrumentation)safety system existing at the EBEplant, in order to maintain safe andsteady operation of processing equipment,it has been recommended to includeinto the modernization programthe following elements: backup emergencystop push button in operator’sroom; staff evacuation audio signal(alarm sirens and beacons) at actuationof emergency shutdown of operation;reducing maximum temperaturesettings on mixers and pumps from150 ° С to 140 ° С; additional installationof protective systems on Netzschstators; Ametist IP type 329-5 01“Flame Announcer” sensors respond-Figure 3. Recommended comprehensive safety operation system of the EBE plantRMZ-M&G 2012, 59

.6670.05=0.35k1,05+D avet( s3≥ Kt ⋅lg R,c410 t D ave ( s)3≥ Kt ⋅lg R,cShemetov, P. A., Bibik, I. P.6 0,43.72 ⋅10⋅ Qc+ 0.65)( 0.5 6 − 0,4ing to 3.72 open ⋅10flame ⋅ Q0.016m)U =1.75U 3emergence with in diameters of blasthole charge, DR –0.01 = Ah + qR ⋅ Cp⋅ ρoutputting1.75R ⋅the Csignal from sensors to wind drift of blasted rock fragments top⋅ ρstaff evacuation audio signal (alarm si-and beacons) should be installed W locity (m/s).leeward side, DR = 5 V; V - wind ve-brens1W0in Wrooms for preparation of oxidizing − ≥ F1W0and −oil solutions, ≥ F packaging, packingV1V0Comparative calculation of maximumandV1cartridgingV0equipment in addition range of blasted rock movement demonstratesthat range of rock movementto fire-control warning system. The developedcomprehensive safety opera-3as ⎡⎛per V the developed ⎤4/340⎞ ⎛ V ⎞ methodology4/340tion system 3 ⎡made ⎛ V it possible to ⎤ σensuresubject ⎢⎜⎟to use ⎜ of ⎟р= − ⋅ К − stemming ⎥ and wind0⎞ ⎛ V0⎞safe σ production ⎢8 ⎢of EBE at the plant and drift ⎣⎝V1is ⎠lower ⎝ V1⎥⎜⎟⎜⎟р= − ⋅ К − ⎥respectively ⎠ ⎦ by 71.5 m8accordingly⎢⎣⎝ V1reduce ⎠ the ⎝ V1existing ⎠ ⎥⎦risk and 46.5 m. Change in routine of bulklevel of the plant from 6.9 points σ to 4.0 blasting in Muruntau deep open pit has1 + σ 2 + σ3points.σmade it possible to enhance effectivenessand safety of blasting operations,1 + σ 2 + σ3ЕIn view Е of the fact that parameters of to reduce downtime of mining transport{[ equipment 1+( 1−2μ)⋅and ε]annual −1}expendi-8/3formula for calculation of range of 38/3rock movement 3 {[ 1+during ( 1−2μ)explosion ⋅ ε]σ− р 1=}− ⋅ К ⋅of tures for blasting operations by USDblastholeσ 8 [ ( ) ] 4р = − ⋅chargesК ⋅1+1−2μ⋅ ε8 at open mining operations,as set forth in effective “Unified105 thousand.[ 1+( 1−2μ)⋅ ε] 4Safety Regulations For Blasting Operations”U ⋅ С р ρU ⋅of Сσ =1992 р ρedition, are relative Conclusionσ =qand nondimensional q values, substantiationqof predictive assessment of blasting,deg operation ree;conducted in proximity 12,5theoretical ⋅СрThus, there have been8/3determined⋅ [ 1+( generalization 1−2μ)⋅εo] −and 1 ⋅ solu-} ⋅( 1+[ of μ)1+scientific ( 1−2μ)⋅εproblem 41+μto γU = 8/3mining 12,5equipment ⋅Сand engineeringр⋅{ [ 1+( 1−2μ)⋅εo] −1tion ] ⋅( 1− of µ ) determinationof regularities of explosiveUofacilitieso=under conditions of 4[ 1+( 1−2μ)⋅εdeepo] ⋅( 1− µ )open pits in terms of damaging action rupture and substantiation of DBO efficient0.228 parameters [ ( suitableof c the blasted rock fragments has been2.281380⋅Q⋅ 1+1−2μ)⋅ε] for the rocko⎛1−µconducted: 0.228 R = 2.280.57to be broken in deep open 0.57 pits ⋅⎜that is, m 1380⋅Q⋅[ 1+( 1−2μ)⋅εo] 0.856 ⎛0.2861−µ ⎞3R0=R mov× K stem+ DR (33) C of ρ great {[ 1+economic ( 1−2μ)⋅εimportance ] }8 / 1o−1and ⎝ + µp ⋅⎜⎟ensures⎝1+reducing0.856 0.2863 0.57where C R 0– maximum {[ 1+( 1−2μ range ) ⋅ε] of rock }8 /o−1µpρ⎠ expenditures for blastingoperations, increasing their effec-movement; R MOV- predictive assessmentof bastσ maximum range of rock Σmove-ment; Σ2( Bn+ КPstem( Bn+ Pntiveness ) subject to application of EBEt= 6,51hr n) - coefficient of stemming with controlled energy using inexpensiveingredients manufactured in thevalue σ = 6,5ninfluence tn on range of rock movement,К stem-1,8= 1/(0.8 + 0.002 L STEM); Republic of Uzbekistan, minimizationof seismic load of blasting on-1,8L STEM- length of stemming expressedthe+)0.4sin2α6m)tg α + C3f51Kσ comуe, m1.13Hde,π ⋅γ− 2q⋅ ctgαbastσt2 − +hrσt{ } ( )⎞⎟⎠0.57− ( 1.5...5.0) d adhole дRMZ-M&G 2012, 59

Physicotechnical substantiation of parameters of blasting operations in deep ...411near-wall rock solid and engineeringstructures, improvement of breakingquality and completeness of extractionof commercial minerals from theearth. A strategy of effective developmentof blasting operations has beendeveloped for mining enterprises thatis aimed at enhancement of safetylevel of blasting operations, technologyof EBE production and blastholescharging.References[1]Tolstov, E. A., Sytenkov, V. N., Phillipov,S. A. (1999): Processes of opencastmining of ore deposits in rockyfiles. The monograph.Publishinghouse «Fan», 276 p., Tashkent.[2]Rubtsov, S. K., Shemetov, P. A. (2011):Management of explosive influenceon a hills at open-cast mining deposits.The monograph.Publishing house«Fan», 400 p., Tashkent.[3]Kucherskiy, N. I. (2007): Modern oftechnology at development of radicaldeposits of gold. The Publishing house«Ore and Metals», 696 p., Moscow.[4]Norov, JU. D., Shemetov, P. A., Bibik,I. P. (2007):Collection of practicalworks in a subject new technologiesand safety at prosecution of explosiveworks. The Publishing house «Bukhara»,166 p., Bukhara.RMZ-M&G 2012, 59

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RMZ – Materials and Geoenvironment, Vol. 59, No. 4, pp. 413–428, 2012413Geophysical and sedimentological studies for reservoircharacterization of some tar sands deposits in southwest NigeriaGeofizikalne in sedimentološke preiskave za opredelitevrezervoarnih lastnosti nekaterih nahajališč naftnega peskav jugozahodni NigerijiAkinmosin, Adewale 1 , Osinowo, O. Olawale 2, * & Osei, M. Martins 31University of Lagos, Geosciences Department, Nigeria2University of Ibadan, Geology Department, Nigeria3Olabisi Onabanjo University, Department of Earth Sciences, Ago-Iwoye, Nigeria*Corresponding author. E-mail: wale.osinowo@mail.ui.edu.ngReceived: April 4, 2012 Accepted: August 16, 2012Abstract: Electrical resistivity tomography for 2-d subsurface imaginghas been integrated with sedimentological and petrophysical analysesfor detailed mapping and reservoir characterization of someNigerian tar sands deposits in southwestern Nigeria with a view togenerate a spatial distribution and reservoir quality description aswell as compare the result with already characterized deposits inother parts of the Nigeria tar sands belt.Electrical resistivity survey delineated a relatively thick (averagethickness of 50 m) high resistivity tar impregnated sand layer withresistivity value range of 1519 Ω m to 5772 Ω m, which is locatedabout 10 m below the ground surface. Granulometric analyses ofeight samples of the tar sands deposit indicate fairly well distributedreservoir sand with grain size distribution range between ф= 0.03–0.55 mm with up to 3 % fines. The reservoir sands is poorto moderately well sorted (ф = 0.94–1.63 mm), the measure ofskewness indicates a strongly coarse to strongly fine skewed (–0.–0.47) reservoir sands. Petrophysical analyses such as porosity andpermeability range from 16–24 % and 143–887 mD, respectively.The tar sands deposit was also analyzed to have between 60–90 %hydrocarbon impregnation, while bitumen saturation of the massfractions 18–30 % was recorded. The viscosity of the impregnatedReview paper

414 Adewale, A., Olawale, O. O., Martins, O. M.heavy oil with API gravity less than 20° and a specific gravityvalue range of 0.95 g/cm 3 to 1.27 g/cm 3 was determined to rangebetween 1.080 Pa s to 1.360 Pa s. The results obtained agreed withborehole information and earlier published geophysical and petrophysicalresults of the tar sands deposits located in other parts ofthe Nigerian tar sands belt.Izvleček: Električna upornostna tomografija s podzemnim 2-d-prikazomv povezavi s sedimentološkimi in petrofizikalnimi analizami je bilauporabljena za detajlno kartiranje in rezervoarno opredelitev nekaterihnahajališč naftnih peskov v jugozahodni Nigeriji z namenomugotoviti prostorski razpored, opredeliti rezervoarne lastnosti in izvestiprimerjavo z že raziskanimi nahajališči v drugih delih nigerijskegapasu naftnih peskov.Z električno upornostjo je bilo mogoče omejiti razmeroma debelo(povprečne debeline 50 m) visoko uporno (v razponu 1519–5772Ω m) plast peska, prepojenega z bitumnom in ležečega okoli 10 mpod površjem. Granulometrična preiskava osmih vzorcev iz nahajališčanaftnega peska nakazuje razmeroma enakomerno porazdelitevrezervoarnega peska z zrnavostjo med ф = 0,03 mm in 0,55 mm inz do 3 % fine frakcije. Rezervoarni pesek je slabo do srednje dobrosortiran (ф = 0.94–1.63 mm), ugotovljena asimetričnost pa nakazujezelo debelozrnato do zelo drobnozrnato asimetrične (–0.58 to 0.47)rezervoarne peske. Rezultati preiskave poroznosti in prepustnosti sov razponih od 16 % do 24 % in ustrezno 143 mD do 887 mD. Stopnjaimpregniranosti z ogljikovodiki se giblje med 60 % in 90 % instopnja nasičenosti z bitumnom med masnima deležima 18 % in 30%. Viskoznost impregnirane težke nafte, ki ima relativno gostotopod 20° API in specifično maso med 0.95 g/cm 3 in 1.27 g/cm 3 , segiblje med 1.080 Pa s in 1.360 Pa s. Dobljeni rezultati ustrezajomeritvam v vrtinah in objavljenim geofizikalnim in petrofizikalnimpodatkom z nahajališč peskov v drugih območjih nigerijskega pasunaftnih peskov.Key words: tomography, reservoir characterization, tar sands, porosity,permeabilityKljučne besede: tomografija, rezervoarna opredelitev, naftni peski, poroznost,prepustnostRMZ-M&G 2012, 59

Geophysical and sedimentological studies for reservoir characterization of ...415IntroductionAsphalt-impregnated sandstones otherwisereferred to as oil sands (tarsands) and active oil-seepages occurin southwestern Nigeria within themarginal pull-apart or margin-sag Dahomey(Benin) basin. The oil sandsoutcrop in an E-W belt, approximately140 km long and 4–6 km wide, extendingfrom Edo, Ondo and Ogun State insouthwest Nigeria. Bituminous sandsare composed of sand, heavy oil andclay that are rich in minerals and water.The heavy oil in the bituminous sand iscommonly called bitumen, which is avery dark coloured, sticky and viscoussubstance. Total reserve of the heavyoil is estimated to exceed 30 billionbarrels (Adegoke et al, 1980).The petroleum habitat is almost exclusivelythe Afowo Formation, a memberof the Abeokuta Group. This litho-unitis of Turonian - Maastrichtian age andconsists of interbeds of coarse-mediumgrained sandstones, siltstones andshale deposited in a transitional to marginalmarine environment (Omatsola& Adegoke, 1981). The oil is found inthe coarse grained clastics within theformation in two discrete bands (the Xand Y horizons), each 30–40 m thickand separated by 6–15 m carbonaceousshales with a thin band of lignite (Akoet al., 1983) and overburden thickness inexcess of 50 m at Agbabu, Ondo State,south western Nigeria (Enu, 1985).This research utilizes electrical resistivitystudies, sedimentological andpetrophysical studies to characterizethe reservoir sands of the tar sand depositsin Gbegude area; a continuum ofthe tar sand belt of North-Eastern Dahomeybasin, South Western Nigeria.The study is aimed at delineating thesubsurface distribution and occurrenceof the deposits as well as determiningthe reservoir characteristics of the tarsand deposits in the study area.Geological settingThe study area is situated in the easternpart of Dahomey basin and locatedwithin longitude 4°22 ’ E to 4° 30 ’ E andlatitude 6° 40 ’ N to 6° 43 ’ N (Figure 1).The Dahomey Basin constitutes partof the system of West African pericratonic(margin sag) basin (Klemme1975; Kingston et al 1983) developedduring the commencement of the riftingand associated with the opening ofthe Gulf of Guinea, in the Late Jurassicto Early Cretaceous (Burke et al,1972; Whiteman, 1982). The crustalseparation, typically preceded by crustalthinning, was accompanied by anextended period of thermally inducedbasin subsidence through the Middle– Upper Cretaceous to Tertiary timesas the South American and the Africanplates entered a drift phase to accommodatethe emerging Atlantic Ocean(Mpanda, 1997).RMZ-M&G 2012, 59

416 Adewale, A., Olawale, O. O., Martins, O. M.Figure 1. Location map of the study area showing sampling and VES points.The basin is bounded in the west by theGhana Ridge which is presumably anoffset extension of the Romanche FractureZone while the Benin hinge line, abasement escarpment which separatesthe Okitipupa Structure from the NigerDelta basin and a continental extensionof the Chain Fracture, bounds it in theeast (Figure 2). The onshore part of thebasin covers a broad arc-shaped profileof about 600 km 2 in extent and attainsa maximum width, along its N-S axis,some 130 km around the Nigerian –Republic of Benin border. The basinnarrows to about 50 km on the easternside where the basement assumes aconvex upwards outline with concomitantthinning of sediments. Along thenortheastern fringe of the basin whereit rims the Okitipupa high is a band oftar (oil) sands and bitumen seepages(Nwachukwu & Ekweozor, 1989).RMZ-M&G 2012, 59

Geophysical and sedimentological studies for reservoir characterization of ...417Figure 2. Generalized geological map of the Eastern Dahomey Basin showing areaextent of the tar sand deposits (Modified after Enu, 1985).Table 1. Regional Stratigraphic Setting of the Eastern Dahomey Basin (After Idowu et al., 1993)RMZ-M&G 2012, 59

418 Adewale, A., Olawale, O. O., Martins, O. M.The lithostratigraphic units of the Cretaceousto Tertiary sedimentary sequenceof eastern margin of Dahomeybasin according to Idowu et al (1993) issummarized in Table 1.Materials and methodsGeophysical, sedimentological andpetrophysical investigation techniqueswere integrated in this study whichrequired both field and laboratorymeasurements. Electrical resistivitydata acquisition involved setting outSchlumberger and Wenner electrodeconfigurations for Vertical ElectricalSoundings (VES) and Electrical ResistivityTomography (ERT), respectively.Zero/low frequency (no inductance)current was injected into the groundvia two current electrodes, the injectedcurrent flow through the earth andgenerates potential difference acrosstwo potential electrodes. The generatedpotential difference was measured withthe aid of ABEM 4000 SAS resistivitymeter. High integrity data (r.m.s. < 5 %)which approximate the apparent resistivityof the subsurface layers were obtainedby integrating the geometric factorof the electrode configuration used.Vertical Electrical Sounding enables1-dimension measurement of variationin subsurface electrical properties withdepth by systematically increasing theseparation between the two currentelectrodes about a symmetrical center.Two dimensional ERT measurementswas performed using Wenner electrodeconfiguration which allows determinationof apparent resistivity values in thehorizontal direction and variation in resistivityvalue with depth by increasingthe electrode spacing. VES and ERTgave insight into the electrical propertydistribution of the earth’s subsurface.Figure 1 presents the location map ofthe study area showing ERT profilesand VES locations.Data ProcessingData processing involved data qualitycheck for spurious and erroneous datawhich may constitute noise. VES datawere plotted on bi-log paper for partialcurve matching using standard twolayer curves and auxiliary CagniardGraph (Koefoed, 1979). This comparesthe observed data curves withtheoretically generated standard curvesand gave some electrical parameterssuch as thickness and resistivity valuesof each layer. The obtained layerparameters served as starting modelfor inversion of the field data usingWinRESIST version 1.0 software. Thishelped to generate sets of earth modelsthat represent the electrical propertiesdistribution of the subsurface. Electricalresistivity subsurface model withhigh geological significance as well asleast misfit between the measured andgenerated data was accepted. ERT datawere also inverted using RES2DINV,version 3.4 developed by Loke, 1999b.RMZ-M&G 2012, 59

Geophysical and sedimentological studies for reservoir characterization of ...419The inversion software is based on theLeast Squared Inversion algorithmwhich performs smoothness constrainedby Least Squared Inversionbased on finite element modeling.Sedimentological and PetrophysicalAnalysesTar sands samples recovered from boreholedrilled to the deposit were analyzedin the laboratory for various granulometricand petrophysical analyses. Mechanicalsieving was carried out usingset of sieve size range from 75 µm to4760 µm. The results of the variousfractions were also employed to determinethe sorting and skewness of thereservoir sands. The effective porosityof the tar sands was determined usinga solid density test (displacement method).The core sample was immersed inwater for ten minutes to allow for initialabsorption in a measuring cylinder.The specimen was then transferred to adisplacement vessel where it displaceda certain volume of liquid (bulk volumeof specimen). The same sampleafter drying to a constant weight waspulverized in mortar and the resultingpowder was carefully transferred into ahalf filled measuring cylinder with liquid.Rodding was then done at interval,to displace any air that may be trappedin it. Afterwards, the reading of the finallevel of the liquid in the cylinder wasnoted. The porosity of the tar sand specimenwas determined using the mathematicalrelation below.Porosity/% = Bulk volume – solid volume/bulkvolume × 100The permeability of the tar sandspecimen was also carried out usingthe Falling Head Permeability Apparatusset. This method measuresthe hydraulic gradient and quantityof water flow into the sample, usinga varying head of water during thetest.Permeability is obtained from the formulaK/(cm/s) = 2.3026 a L/A(lg H 1– lg H 2)/(t 2– t 1)Where K is the coefficient of permeabilityis obtained from the formulaa - cross-sectional area of the standpipeL - length of soil sample in permeameterA - cross-sectional area of the permeameterH 1& H 2- the heads between which thepermeability is determined.t 1- time when water in the standpipeis at H 1t 2- time when water in the standpipeis at H 2The specific gravity and API gravityof the extracted oil was obtainedby measuring displacement in water.The viscosity of tar extract was alsodone using a cone plate viscometer.The tar extraction was done using theSoxhlet extractor. This was achievedby placing the tar sands in the thim-RMZ-M&G 2012, 59

420 Adewale, A., Olawale, O. O., Martins, O. M.ble made from thick filter papersloaded in the main chamber of theapparatus and placed on a flask containingthe extraction solvent. Thesolvent is heated to reflux, releasingits vapour to travel up the distillationarm. A condenser ensures thatthe solvent vapour cools and dripsback into the chamber housing thetar materials. The chamber containingthe solid material is slowly filledwith the warm solvent. When theSoxhlet chamber is almost filled, it isautomatically emptied by siphon sidearm with the solvent running downinto the distillation flask. This cycleis allowed to repeat many times, overhours or days.Results and discussionElectrical resistivity method has foundwide and successful application both insurface and borehole measurements todifferentiate hydrocarbon saturated regionfrom saline water saturated sandon the account of very high resistivitysignature of hydrocarbon pore fluidsthat are incapable of ionic conduction(Winsauer et al, 1952). Representativeresistivity VES curves obtained after1-d inversion of the field data are presentedin figure 3 (a–c). The interpretationof the resistivity layered parameterswas constrained by core and drillcuttings information from a drilledborehole from where samples werea)RMZ-M&G 2012, 59

Geophysical and sedimentological studies for reservoir characterization of ...421b)c)Figure 3. VES Curves obtained from the Study AreaRMZ-M&G 2012, 59

422 Adewale, A., Olawale, O. O., Martins, O. M.recovered for laboratory studies. Thelayer with the highest resistivity valuecorresponds to the section in the boreholewith tar impregnated sand. Thetar sands layers delineated from resistivityinvestigation range in thicknessfrom 17–72 m with resistivity valuesof 1515–5773 Ω m. The obtained resultsindicate a general reduction trendtoward the west, in the tar sands layerthickness and resistivity. High resistivityvalues of the tar impregnated layerFigure 4. Raw data, pseudosection and 2-d resistivity inverted section across GbegudeII profile.RMZ-M&G 2012, 59

Geophysical and sedimentological studies for reservoir characterization of ...423were recorded; this is likely due to thefact that the heavy hydrocarbon oilswhich fill the pore spaces are molecularcompounds which are poor conductorof electricity. However, low resistivitytar sands deposits are also commonlyencountered in the southern part of theNigerian tar sand belt. This is probablybecause the tar sands in this regionare water wet (Adegoke et. al, 1981),where the incorporated/impregnatedsaline water enables ionic conducion.Figure 5. Raw data, pseudosection and 2d resistivity inverted section across Goodluckprofile.RMZ-M&G 2012, 59

424 Adewale, A., Olawale, O. O., Martins, O. M.Figures 4 and 5 present the ERT rawdata, calculated pseudosection and 2-dinverted resistivity data across the fieldalong the E-W profile. The plot alsodelineates the high resistivity layer tobe tar impregnated. This agrees withVES results and borehole information.Sedimentological Analyses ResultsThe mechanical sieve analysis gave anaverage grain size distribution of thereservoir sand to range from ф = 0.03–0.55 mm, which indicates a medium tocoarse sands. The skewness of the reservoirsand was determined to rangesfrom –0.58–0.47, indicating stronglycoarse to strongly fine skewed according(Folk, 1974). This result definesa high energy of deposition at Ebute,Shofini and Bakue, but lower at Gbegude,thus accounting for the 2.5 % offines in its composition. The sortingof the reservoir sands ranges in valuesfrom ф = 0.82 mm (moderately sorted)to ф = 1.63 mm (poorly sorted) accordingto Folks`1974 classification, whilethe percentage of fines collected werecomposed of silt and kaolinitic claysin the range of 1–3 %. The summaryof the granulometric analyses results ispresented in table 2.Depth of occurrence of the tar sanddeposits affects the volume of voidsas well as the precipitation of bitumenduring migration by fines due to geopetalaccumulation (Lomando, 1986and 1992; Dutton & Finley, 1988)which has the tendency to result in areduction of pore throats and porosity.The moderate to high porosity valuesobtained for the reservoir sands, whichrange from 16–24 %, (Cole & Christopher,1992; Wallace & John, 1992, Lomando,1992). The interconnectivity ofpore spaces to transmit fluid is howeverobstructed by the precipitation of finesfrom migrating fluids which reducedthe pore throats. In addition, the degreeof sorting as well as the measure ofskewness also affects the degree of reservoir’spermeability. This is because astrongly coarse skewed reservoir sandsis expected to have larger pore throats,which if interconnected is expected tobe highly permeable. The permeabilitymay be reduced however where thepore throats are blocked by fines in caseof poorly sorted reservoir sands. Mostof the reservoir sands are moderatelysorted, which is a good reservoir quality.Permeability is also dependent onthe effective grain size of the reservoirsand (Schlumberger, 1989). It can bestated from this study that the larger theeffective grain size, the greater the permeabilityas evident in Table 3. Moreso, the presence or abundance of finesin a reservoir reduces the permeabilityof the reservoir. This was observed inthe analyzed samples. It was observedthat the poorly sorted reservoir sand atGbegude with about 2.5 % of fines recordthe lowest permeability value of143 mD. While the reservoir at EbuteRMZ-M&G 2012, 59

Geophysical and sedimentological studies for reservoir characterization of ...425Table 2. Summary of the result of granulometric analyses of the tar sands deposit.SampleMeanф/mmSortingф/mmRemark: Folk,1974 Skewness Remark: Folk, 1974Gbegude 3 0.033 1.5 Poorly sorted 0.34 strongly fine skewedShofini 12 0.55 0.82 Moderately sorted –0.58 strongly coarse skewedShofini 13 0.26 1.63 Poorly sorted 0.47 strongly fine skewedEbute 14 0.53 0.93 Moderately sorted –0.32 strongly coarse skewedBakue 18 0.52 0.94 Moderately sorted –0.43 strongly coarse skewedTable 3. Relationship between Reservoir Grain Size, Porosity and Permeability.Sample D10(mm) Porosity (%) Perm. k. (mD)AB1 0.51 23.08 3053.8B18 0.43 23.72 215.4G1 0.87 20.78 887.53G3 0.35 16.22 143.03E14 0.45 23.36 236.44SH12 0.47 21.9 257.9SH13 0.42 23.32 210M5 0.57 22.37 3826.74Table 4. API gravity values of oil grades(USGS, 2000).Light Oil22.3 021.6 0Heavy Oil10.0 06.5 0Extra Heavy Oil0.1 0and Shofini were moderately sortedwith amount of fines less than 2 % andpermeability values greater than 215mD. Finally, from the study, the permeabilityvalues are found to be moderateto very high (Cole & Christopher,1992).The API gravity values obtained in thearea are all below 20°, this indicatesthat the tar sands are composed ofHeavy and Extra Heavy Oils accordingto the USGS scale of oil grades (USGS,2000), (Table 4). This implies that extractedbitumen is moderately biodegradedand contains good proportionof Asphaltene and Heavy Oil whichare responsible for the high resistivityvalues of the tar sand obtained from theresistivity survey. The bitumen in thisarea is highly viscous with viscosity of1080 cP and 1360 cP in Gbegude andAgo – Alaaye respectively. The bitumencontent of the tar sand samplesanalyzed ranged from mass fractions18 % to 30 %.RMZ-M&G 2012, 59

426 Adewale, A., Olawale, O. O., Martins, O. M.ConclusionThe high porosity and permeabilityvalues obtained and the degree of sortingof the reservoir sands are indicationsof a good reservoir quality in thestudy area. Also, the viscosity and specificgravity values obtained from theanalyses indicate highly viscous andlow specific gravity oil. These, coupledwith high asphaltene content arean indication of severe biodegradation.Moreover, result of API gravity equallyshowed that the deposits belong tothe class of heavy oil. The biodegraded,low viscous low API gravity of thetar which impregnated the sands explainsthe high resistivity value of thetar sands deposit around the study areain addition to the fact that molecularcompounds (hydrocarbons) are incapableof ionic conduction.The reservoir characteristics of the tarsands in Gbegude area are similar tothose earlier studied by other researchers,in that porosity values obtained fallbetween 16–24 %; percentage of finesranges from 1–7 %, and are mainly composedof kaolinitic clay and silt; depthof burial ranges from 0 m to >50 m; tarsand reservoir is about 18–72 m thick.ReferencesAdegoke, O. S., Enu, E. I., Ajayi, T. R.,Ako, B. D., Omatsola, M. E. & Afonja,A. A. (1981): Tarsand, a New EnergyRaw Material in Nigeria. Proc.Symp. On New Energy Raw Material,Karlovy Vary, p. 17–22.Adegoke, O. S., Ako, B. D., Enu, E. I(1980): Geotechnical Investigationsof Ondo State Bituminous Sands. Vol.1. Geology and Reserve Estimate,Report. Geological Consulting Unit,Dept. of Geology, University of Ife,Ile-Ife, pp. 257.Ako, B. D., Alabi, A. O., Adegoke, O. S.& Enu, E. I. (1983): Application of ResistivitySounding in the Explorationfor Nigerian Tar sand. Energy Explorationand Exploitation, Vol. 2, No. 2,p. 155–164.Burke, K. C. B., Dessauvagie, T. F. J.,Whiteman, A. J (1972): The Openingof the Gulf of Guinea and GeologicalHistory of Benue Depression and NigerDelta, Nature, Physical Science,233 (38), p. 12–21.Cole, R. D. & Christopher E. M. (1992):Reservoir Characterization of TensleepSandstone, South Casper Creek Field,Wyoming, and (abs): AAPG Bulletin,Vol. 76, No. 8, p. 1257.Dutton, S. P. & Finley R. J. (1988);Controls on Reservoir Quality inTight Sandstone of the Travis PeakFormation, East Texas: SPE FormationEvaluation, Vol. 3, No. 1, p.97–104.Enu, E. I. (1985): Textural Characteristicsof the Nigerian Tar sand. Sed. Geol.44, pp. 65–81.Folk, R. L. (1974): Petrology of SedimentaryRocks. Hemphill Publ. Co., Austin.Texas. pp. 159.Idowu, J. O., Ajiboye, S. A., Ilesanmi, M.RMZ-M&G 2012, 59

Geophysical and sedimentological studies for reservoir characterization of ...427A. & Tanimola, A. (1993): Origin andignificance of Organic Matter of OshosunFormation, South Western DahomeyBasin, Nigeria. Journal of Miningand Geology. Vol. 29, 9–17.Klemme, H. D. (1975): Geothermal Gradients,Heatflow and Hydrocarbon Recovery.In: A.G. Fischer and S.Judson(Eds), Petroleum and Global Tectonics.Princeton, New Jersey, PrincetonUniv. Press, pp. 251–304.Kingston, D. R., Dishroon, C. P. & Williams,P. A. (1983): Global Basin ClassificationSystem. AAPG. Bull., Vol.67, 2175–2193.Koefoed, O. (1979): Geosounding Principles1: Resistivity Sounding Measurements.Elsevier Science PublishingCompany, Amsterdam, pp: 635.Loke, M. H. (1999): Time lapse resistivityimaging inversion, Proceedings ofthe 5 th Meeting of the EEGS EuropeanSection, Em1.Lomando, A. J. (1986): Solid Hydrocarbon:A Migration of Fines Problemin Carbonate reservoirs (abs): AAPGBulletin, Vol.70, p. 612.Lomando, A. J. (1992): The Influence ofSolid Reservoir Bitumen on ReservoirQuality: AAPG Bulletin, Vol. 76, No.8, pp. 1137–1152.Mpanda, S. (1997): Geological developmentof east African coastal basin ofTanzania. Acta Universities, Stockholmiensis,Vol. 45, p. 121.Nwachukwu, S. O. & Ekweozor, C. M.(1989): Origin of Tar sands In SouthwesternNigeria. Nigeria Associationof Petroleum Exploration. Bulletin 4,p. 82–94.Omotsola, M. E. & Adegoke, O. S. (1981):Tectonic Evolution and CretaceousStratigraphy of the Dahomey Basin.Nig. Jour. Min. and Geol. Vol. 18, p.130–137.Schlumberger (1989): Log Interpretationprinciples; pp. 8–9.United State Geological Survey (2000):Producing Asphaltenic Crude Oils:Problems and Solutions. PetroleumEngineer, June edition, p. 24–31.Wallace, K. J. & John J. H. (1992): AnIntegrated Exploration Effort for MorrowSandstones in Southeast Colorado,(abs): AAPG Bull., Vol. 76, No.8, p. 1270.Whiteman, A. J. (1982): Nigeria: Its PetroleumGeology, Resources and Potential;p. 82–86.Winsauer, W. O., Shearin, H. M., Masson,P. H. & Williams, M. (1952):Resistivity of brine saturated sands inrelation to pore geometry. AAPG Bulletin.36, p. 2.RMZ-M&G 2012, 59

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RMZ – Materials and Geoenvironment, Vol. 59, No. 4, pp. 429–442, 2012429Technological process and equipment selection for excavation ofnatural stone in Lipica quarryIzbira tehnološkega procesa in opreme za pridobivanje naravnegakamna v kamnolomu LipicaAndrej Kos 1, * , Evgen Dervarič 21MARMOR, Sežana, d. d.; Partizanska cesta 73a, SI-6210 Sežana, Slovenia2Univerza v Ljubljani, Naravoslovnotehniška fakulteta, Oddelek za geotehnologijo inrudarstvo, Aškerčeva 12, SI-1000 Ljubljana, Slovenia*Corresponding author. E-mail: kos@marmorsezana.comReceived: November 6, 2012 Accepted: December 12, 2012Abstract: Stone is an important part of nature. When man realised thatstone is useful, they started to think of easiest methods of its exploitation.Through the centuries, there have been numerous researchstudies and development of expertise necessary for selection ofnatural stone, methods of its exploitation and most effective proceduresfor its processing. The development is still continuing today.Improvements in the field of technology have resulted in increasedproduction, safer work procedures and transition from open surfaceto underground excavation methods. The article presents the developmentof quarry equipments, proper selection of the technologicalprocess and introduction of the new chain saw cutting machine inexcavation of natural stone (i.e. limestone) in the quarries of thecompany Marmor, Sežana, d. d.Izvleček: Kamen je pomemben del narave. Ko je človek spoznal, da je kamenuporaben, je začel razmišljati o njegovem najlažjem pridobivanju.Skozi stoletja so tekle mnoge raziskave in razvoj potrebnih znanjs ciljem izbire naravnega kamna, načina njegovega pridobivanja inpostopkov najbolj učinkovite obdelave. Ta razvoj se nadaljuje tudidanes. Izboljšave na področju tehnologije niso omogočile le povečanjaproizvodnje, temveč tudi varnejše delo in prehod s površinskegana podzemni način pridobivanja. V članku je predstavljen razvoj kamnolomskeopreme, pravilna izbira tehnološkega procesa in uvedbaReview paper

430 Kos, A., Dervarič, E.novega verižnega zasekovalnega stroja pri pridobivanju naravnegakamna – apnenca v kamnolomih družbe Marmor, Sežana, d. d.Key words: underground excavation of natural stone, geological studies,mineral raw materials, chain saw machinesKljučne besede: podzemno pridobivanje naravnega kamna, geološkeraziskave, mineralne surovine, verižne žageIntroductionNatural stone used for constructionpurposes are the rocks whose colour,compactness or other properties areappealing to a human eye. They wereused by old civilisations to glorify theirmonarchs or even to make them equalto gods. It is precisely the use of stonethat made it possible for many greatachievements of the past to remain preserveduntil today.A special and distinctive feature of naturalstone is its hardness, stability andits possibility of shaping. Natural stoneis unique and exceptional in itself, asits colours and structure are very differentand dependent of the nature.Beside physical and mechanical propertiesof stone, the excavation methodis also influenced by mining and geologicalconditions as well as technicalconditions of excavation. Judging fromexperience, the most problems in naturalstone excavation are caused by tectonicinfluences, mainly cracking andfragmentation which, together withstratification and karstification, usuallysignificantly reduce the yield or evenprevent further excavation of blocks ofnatural stone.Additionally, the excavation processesand the final yield in a quarry are mostlyinfluenced by the excavation method,the use of suitable equipment andutilisation of natural features of stone.Development of quarry equipmentNatural stone is undoubtedly the materialthat has been used by man throughoutthe entire history. The prehistoricman exploited the stone by collectingit from the ground or breaking and diggingto the depth or size easily liftedand transported. The stone was processedby means of stone and woodentools. After discovery of metals, metaltools were used for stone processing.The man used stone for tools andweapons in the struggle against natureand for construction purposes. Beautifulstone blocks were used for makingmonuments, doorposts, portals, etc.The material was transported by oxen,horses, etc. [5]RMZ-M&G 2012, 59

Izbira tehnološkega procesa in opreme za pridobivanje naravnega kamna ...431Until a few decades ago, the exploitationof stone was based on makinguse of its natural properties, mainlythe cracks which were used for breakingthe stone into smaller pieces. Allworks were done on the surface,manually, with primitive tools suchas mallets, chisels, picks and varioussimple levers. The pieces of stoneappearing on the surface were carvedby picks and mallets until they broke.The work was long-lasting and strenuous.A true revolution in the quarry workwas brought about by boring drills. Thework was still manual. Natural featuresof sites were exploited. In winter, peoplepoured water in cracks. Freezingwater expanded the cracks and madebreaking of stone easier. Hazelnut rodsand oak wedges were also used; theywere hammered into cracks and moistenedwith water. [2]The development of pneumatic drillingtools additionally changed andincreased the production. Using pneumaticdrilling equipment, people drilledunder and around the rock mass whichwas then split into smaller blocks bymeans of wedges and heavy mallets. Inmost cases, they made use of naturalfeatures of the sites (discontinuities,stratification, etc.), but they also usedvarious emulsions, gunpowder anddetonating cord to split the rock massapart. [3]The development of quarry equipmentcontinued with helicoid wireand quartz sand. This method was firstused in the year 1854. In our country,it continued to be used by mid-1980s.At cutting sites, vertical bores with adiameter of 240 mm and 360 mm andhorizontal bores with a diameter of 90mm were first drilled. A 5.8 mm helicoidwire was threaded through thebores and used, together with quartzsand, for cutting of stone. An engineroom with a diesel aggregate was requiredfor the start-up. Water was usedas an additive and a coolant. The cuttingefficiency was low, amounting to1.5 m 2 /h to 2.0 m 2 /h, depending on thehardness of the stone. The length of thewire system line was sometimes up to2.5 km. [2] In the present time, helicoidwire has been replaced by diamondwire.A new revolution in quarry mining wasintroduction of diamond wire saw. Thefirst diamond wire saws came into operationin the 1970s. The cutting processis similar to the preceding technology;i.e. a combined method withpreviously drilled bores (34–90 mm indiameter) and diamond wire saw. Thespeed of cutting ranged from 8 m 2 /h to12 m 2 /h, which meant new possibilitiesin exploitation and processing of naturalstone. In the beginning, diamondwire saws with 30 kW (40 hp) motorswere used, which allowed cuttingof surfaces of up to 150 m 2 . [2] Today,RMZ-M&G 2012, 59

432 Kos, A., Dervarič, E.diamond wire saws with 19–56 kW(25–75 hp) motors are used, allowingcuts of up to 300 m 2 . The use of waterand wet cutting is compulsory, as itextends the service life of the diamondwire. The use of diamonds depends onthe structure, compactness and type ofthe stone.Additional development of quarryequipment was brought about by theintroduction of chain saw cutting machines.The machine’s principle issimilar to that of a power wood saw;however, the machine has larger dimensionsand an additional hydraulicand electrical system. The most importantcomponent of the machine is ablade with a chain. The blades are ofvarious lengths, ranging from 1.5 m to7 m, depending on the use of the machine.Cutting of stone is performedby using a chain blade with “widia”or diamond plates mounted on it. Diamondplates are made of small grainsof polycrystalline diamond introducedin the tungsten carbide base. The platesare mounted, in different directions, inbrackets on the chain. We have an optionof wet or dry cutting.Figure 1. Illustration of exploitation by means of the drilling equipment and diamondwire saw [1]RMZ-M&G 2012, 59

Izbira tehnološkega procesa in opreme za pridobivanje naravnega kamna ...433Figure 2. A track chain saw and cutting elements [6]Figure 3. An old and a new model of the chain saw machine for underground mining.Left: the Fantini G. 70 model on fixing pillars. Right: the new Fantini GU 70/R model. [6]Chain saw cutting machines were first producedfor open-surface exploitation shownin Figure 2. The construction of the machineallowed both horizontal and verticalcuts. In the beginning, machines for undergroundexcavations were designed to havethe cutting machine mounted on fixing pillarswhich allowed raising and lowering ofthe cutting section (Figure 3 - left).Deficiencies of older models encouragedthe development of cutting ma-RMZ-M&G 2012, 59

434 Kos, A., Dervarič, E.chines towards greater mobility. So,presently, chain saw cutting machinesare being used that consist of a singlesegment and have their own mobileunit. Due to their mobility, they can beused for both open-surface and undergroundexploitation.The Fantini G.70 chain saw cuttingmachine has been used by the companyMarmor, Sežana, d. d., since theyear 2002. As evident from the photo,transportation of the machine requiresa high-performance loader. Additionally,the connection to the control unitis done via hydraulic hoses which mustbe disconnected and reconnected forevery movement of the machine. Machinesetting procedures require a lotof time; approximately 2 h are neededfor each cut. An advance section consistsof four horizontal and three verticalcuts.An upgrade to the old Fantini G. 70cutting machine is represented by numerousnew mobile models. At thecompany Marmor, Sežana, d. d., wehave selected the Fantini GU 70/Rmodel. The Fantini GU 70/R modelhas been upgraded with a mobile unit,problems with hydraulic hoses havebeen eliminated, its dimensions andmobility allow cutting of larger widthsand lengths, rotation of the blade inseveral directions allows cutting of therear wall. After finished cutting, themachine automatically corrects the cutin order to avoid the risk of cutting intothe safety pillars. Diamond cutting elementsare used for cutting. An advancesection cut with the new machine consistsof five horizontal and three verticalcuts.Advance effects resulting from the introductionof the new machine com-Table 1. Presentation of properties of both Fantini chain saw cutting machines [6]Chain saw cutting machineFantini G.70Mobile chain saw cutting machineFantini GU 70/RWeight 6 000 kg 26 000 kgWeight of the hydraulic unit 2 000 kg -Total installed power 52.2 kW 60 kWBlade run speed 0–0.07 m/min 0–0.08 m/minHydraulic oil tank capacity 300 l 450 lCut width 38 mm 38 mmBlade length 2 900 mm 3 200 mmMinimum gallery advance 71 m 3 85 m 3Minimum advance section cuttingcycle41 h 47 hMaximum height of cutting 4.5 m 5.4 mRMZ-M&G 2012, 59

Izbira tehnološkega procesa in opreme za pridobivanje naravnega kamna ...435pared to the previous model:• approximately 20 % more materialexcavated from a minimum advancesection,• the time required for setting themachine before operation has beencut in half,• easier movement and faster retreatfrom the cutting location in case ofdanger,• a new blade and electronics preventthe risk of cutting into the safetypillars,• modified geometry of cutting theadvance section (increased distancesbetween cuts).Beside the cutting equipment, naturalstone excavation also requires highperformanceloaders, powerful compressors,lifts, hydraulic rollers andwater cushions with a water pump.The effective cutting depth of the newFantini GU 70/R machine is 3.2 m. Thegeometry of cuts consists of five horizontaland three vertical cuts. If comparedto the previous Fantini G.70 machine,the distribution of horizontal cutsis changed by adding another horizontalcut which increases the height of the undergroundterrain from 4.5 m to 5.2 mor more. The distribution is adapted toFigure 4. Geometry of distribution of cuts in the use of the new Fantini GU 70/R cuttingmachineRMZ-M&G 2012, 59

436 Kos, A., Dervarič, E.the best possible yield of material froman advance section. Lower distancesbetween horizontal cuts have been increasedin order to obtain blocks ofmaximum height dimensions for furtherprocessing. Certain horizontal cuts canbe omitted, but due to the structure andcracking of the site, this might aggravatethe work and increase the exploitationcosts. As excavation at higher levels ismore difficult, the distances betweenhorizontal cuts are increasingly smallerwith height. In the excavation of naturalstone from quarries of Marmor, Sežana,d. d., the cutting geometry as illustratedin Figure 4 is used. Sometimes, a horizontalcut can be omitted, contributingto a better yield from an advance section.Selection of equipmentQuarry equipment requires careful selection,as the use of unsuitable equipmentsignificantly increases excavationcosts.Before selecting the machines, the followingresearch should be done:• geological studies must be made toestablish the geological structure,reserves and quality of the mineralmaterial,• geomechanical studies must bemade to establish the physical andmechanical parameters of the material,strength, abrasiveness, possibilityof swelling, chemical andmineral structure.Before selecting the equipment, an appropriateexcavation method shouldbe selected; i.e. either surface or undergroundexcavation. On the surface,a method of excavation from top tobottom is used; the height of exploitationfloors is usually 3 m to 6 m. Inunderground excavation, the combinedFigure 5. Open surface and underground excavation - Lipica 1 quarry.RMZ-M&G 2012, 59

Izbira tehnološkega procesa in opreme za pridobivanje naravnega kamna ...437chamber-and-pillar method is used. Init of great importance that at the firstlevel the distribution of cuts is preciselydetermined, as it influences the finalyield of material.Selection of the excavation method orthe proper cutting system depends on thetype of the material, compactness, quantityand price of the material. In mostcases, faster and better work requirescombination of various cutting machinesto obtain satisfactory excavation results.Cutting equipment in quarries shouldbe complemented by high performanceloaders, as larger and more powerfulmachines make the excavation processeasier and more economic. In excavationoperations, the use of variousbumper cylinders, water and air cushionsis also required.Cutting performance comparisonThe reasons for underground excavationof natural stone are the following:• geological properties of the site,• selective excavation of naturalstone,• less environmental damage andless environmental noise,• work is possible in any weatherconditions,• possibilities for the use of such undergroundlocations after finishedexcavation works.Because of the transfer to undergroundexploitation, a research is done on theimpact of the underground exploitationmethod that is applied in LipicaII to the surface [8] . The results of theresearch have shown that the methodof underground exploitation applied toLipica II does not have an impact onthe surface. As there is no movement inany direction, there is no deformationand the surface has stayed the same (asif no work is being done below). It hasbeen expected that there will not beany impact to the surface, on the base[9], but because of the specificity of LipicaII, adapted research of [8] researchhad to be done.Demand for natural stone blocks, increasedproduction in the quarries, costreduction in the process of excavationof natural stone and safer work operationsare the main requirements regardingthe excavation which have contributedto the development of a newermodel of chain saw cutting machines.Relocation of production from the surfaceto the underground required thedevelopment of technology suitablefor underground excavation. Initially,chain saw cutting machines with fixatingpillars were used (Figure 3 - left).The Fantini G. 70 machine consistsof two segments: the cutting segmentand the hydraulic control segment. Themachine is transported to and fromthe cutting site by means of a loader.RMZ-M&G 2012, 59

438 Kos, A., Dervarič, E.Before the beginning of each cuttingoperation, it takes the operators approximatelytwo hours to prepare themachines, set the blade in a horizontalposition and to rotate the cutting elements.Before every movement of themachine, it is required to disconnectand arrange the hydraulic hoses. Whenmaking the first sections in a gallery,where fixation of pillars in the ceilingis not possible, stabilisation by meansof chains is required. Problems mayoccur in the event of crumbling of thefront section, with numerous instancesof damage to the pillars.Models of chain saw cutting machinesare very different. Types of machinesdepend on the customers’ requirements.There are several models of chain sawcutting machines. The machines aredistinguished from each other by theirintended use, cutting characteristics,dimensions and their electrical andhydraulic equipment. The newer machineshave certain additional features:• the machine’s mobility,• increased cutting height,• the shape of the blade, an automaticblade levelling function has beenadded,• faster movement in larger cuttingwidths,• possible cutting of the back cut ofan advance section,• elimination of deficiencies of hydrauliccables,• a computer to monitor the cuttingparameters,• remote control of the machine.• the weight of the machines allowseasier start in making the first sectionsin a gallery.With the new Fantini 70 GU/R machine,the deficiencies have been eliminatedand improved. The comparison of theresults between the machines G.70 and70 GU/R is given in the table 1.By introducing a new Fantini GU 70/Rchain saw cutting machine, the companyMarmor, Sežana, d. d., has acquireda machine of high quality and high performance.Compared to the old model,G.70, the minimum advance section(5.6 m × 4.5 m × 2.8 m) has been increasedin height from 4.5 m to 5.2 mand in depth from 2.8 m to 3.0 m, thusharvesting by 20 % more material froma minimum advance section than byusing the old model. Both the old andthe new machine can be used to immediatelystart cutting the maximumwidth of a gallery. With the new chainsaw cutting machine, approximatelyseven working days are required for anadvance section of approximate size of150 m 3 ; with the older G.70 model, atleast nine working days were required.The only problem that occurred wasthe construction of initial crossroads ina gallery, as the length of the new machineprevented its positioning in thedirection of advancement. Therefore,we had to position the machine diago-RMZ-M&G 2012, 59

Izbira tehnološkega procesa in opreme za pridobivanje naravnega kamna ...439Figure 6. Illustration of making a vertical and horizontal cut by using the Fantini GU70/R chain saw cutting machine and the XXL blade [6]Figure 7. Comparison of initial cuts for a gallery with both Fantini machines [4]RMZ-M&G 2012, 59Figure 8. Arrangement of cutting elements in a cut [4]

440 Kos, A., Dervarič, E.nally to the front and begin cutting inthe material.The arrangement of cutting plates onthe chain (shown in Figure 8). Thethickness of the cut is still 38 mm,and the system of the blade with cuttingplates has remained the same. Differentshaped on cutting elements areused: square, trapezoidal, star-shapedand round cross-cut sections of cuttingelements. The shapes depend onthe properties of the materials beingcut as well as on the structure of “widia”plates. In our production, we usesquare-shaped “widia” plates, whichcan be rotated eight times, and roundshapeddiamond cutting elements. Thedifference between the both is in price;the diamond plates are 10 times moreexpensive and more durable.A proper distribution of horizontal andvertical cuts can also affect the yieldof material, but it requires supervisor'sconstant monitoring and control, as thegeological and safety conditions in astone quarry change from one advancesection to another.ConclusionTechnological development in theproduction of natural stone is still anongoing process. In the exploitationindustry, there is an increasing collaborationamong the manufacturersof working equipment and customers,as they together provide developmentof new and better equipment.New modifications to machines usedin quarry work facilitate excavationand processing of the material. Thereare numerous manufacturers of chainsaw cutting machines worldwide.Customers can choose from modelsthat are most suitable for characteristicsof their sites, their excavationpreferences and prices. A great emphasisis on the production of suitabletools and cutting elements fordifferent types of natural stone, aseach material has its own properties.A new technology which is increasinglygaining in importance is the socalledwaterjet technology, i.e. cuttingof material by means of a waterjet. The said technology is currentlyused primarily for processing of materialin workshops.Proper selection of technology requiresprevious elaboration of detailedgeological and laboratory studies (mechanicaland physical parameters ofstone, chemical composition of the material),economic assessment of the siteand consideration of nature protectionconditions.Based on results of the studies, wecan select the optimal technology andtechnological processes of excavationto achieve satisfactory economic andtechnological results.RMZ-M&G 2012, 59

Izbira tehnološkega procesa in opreme za pridobivanje naravnega kamna ...441Despite continuous development of thetechnology, excavation of natural stonestill requires consideration of naturalfeatures of sites and properties of stone,as they were observed in the past.References[1]Čuk, S. (2004): Tunelsko pridobivanjeokrasnega kamna. Diplomsko delo vvišjem strokovnem izobraževalnemprogramu gradbeništvo, str. 80.[2]Jesenko, J., Kortnik, J., Pivk, S.(2009): Podzemno pridobivanje blokovnaravnega kamna v kamnolomuHotavlje I., Posvetovanje rudarskih ingeotehnoloških strokovnjakov ob 41.Skoku čez kožo, str. 70–82.[3]Kortnik, J. (2009): Underground naturalstone excavation technics in Slovenia,RMZ –Materials and Geoenviroment,Vol. 56, No. 2, p. 202–2011.[4]Primavori, P. (2005): Il manuale dellatagliatrice a catena. Fantini Sud s.p.a ,Strada Prov.le 12, no®52 – 03012 Anahni(FR), 127.[5]Vesel, J., Škerlj, J., Čebulj, A.,Grmiščar, A. (1975): Nahajališča naravnegakamna v Sloveniji, Geološkizavod, Ljubljana, Slovensko geološkodruštvo, letnik 18, številka 15.[6]Podjetje Fantini Spa. Dostopno na internetnistrani: http://www.fantinispa.it, 13.3.2012[7]Arhiv strokovne dokumentacije podjetjaMarmor, Sežana, d. d.[8]Rošer, J., Ristović, I., Vulić, M.(2010): Applicability of continuousreal-time monitoring systems in safetyassurance of significant structures.Strojarstvo, kolovoz 2010, god. 52, br.4, str. 449–458.[9]Medved, M., vulić, M. (2010): Continuousmonitoring system in tunnelling.TTEM. Tech. technol. educ. manag.,Vol. 5, No. 4, p. 663–668.RMZ-M&G 2012, 59

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RMZ – Materials and Geoenvironment, Vol. 59, No. 4, pp. 443–468, 2012443Železniška livarna v ŠiškiRailway-foundry in ŠiškaAleš Lajovic *Ilirska 18, SI-1000 Ljubljana, Slovenija*Korespondenčni avtor. E-mail: ales.lajovic@gmail.comReceived: October 26, 2012 Accepted: November 26, 2012Izvleček: Že kmalu po dograditvi Južne železnice med Dunajem in Trstomso v Ljubljani v Šiški postavili zelo dobro opremljene železniške vzdrževalnedelavnice (t. i. Kurilnico) in v njihovem sklopu tudi livarno(leta 1868). Po zatonu parne vleke in drsnih ležajev se je potreba poulitkih iz barvnih kovin zelo zmanjšala, z naraščajočim prometom pamočno povečala poraba zavornih oblog, ki so na železnici navadnoizdelane iz sive litine s specifično kemično sestavo. Postavljena jebila nova livarna, ki se je z leti mehanizirala. Produkcija je rastla in vosemdesetih letih preteklega stoletja dosegla letno proizvodnjo okoli3000 ton – pretežno za železniške potrebe. Po razpadu Jugoslavije seje povpraševanje po ulitkih najprej prepolovilo, kasneje pa, tudi zaradiuvedbe novih vlakov z diskastimi zavorami, še nadalje manjšalo.Livarna je prenehala delo oktobra 2003, delavci pa so bili prerazporejenipo drugih obratih.Abstract: Soon after the Austrian Southern Railway was build betweenVienna and Trieste, well-equipped railway maintenance workshops(so-called Engine-Shed) and a foundry (in year 1868) were set up inŠiška. After the fall in use of steam locomotives and sliding bearings,the need for castings made from non-ferrous metals declined significantly.However, the use of brake pads, for railway use usually madefrom grey cast iron with a specific chemical composition, was on therise due to the increased traffic. A new foundry was built that eventuallybecame mechanized. The production grew and in the 1980s, itreached approximately 3000 tons of iron per year, used mostly forrailway purposes. After the breakup of Yugoslavia, the demand forcastings reduced by two, and later, with the introduction of trains withProfessional paper

444 Lajovic, A.disc brakes, further decreased. The foundry shut down in 2003 and theworkers were redirected to other industrial plants.Ključne besede: železnica, livarna, siva litina, centrifugalni napajalniki,obloge za termitno varjenje tračnicKey words: railway, foundry, gray cast iron, centrifugal feeders, refractorymolds for thermit process casting of railsUvodPestra geološka struktura ljubljanskekotline in pomembne trgovske potiskoznjo so imele med drugim za posledico,da so se njeni prebivalci že vsaj2000 let pred našim štetjem ukvarjalitudi z ulivanjem kovinskih predmetov(kalupi in ulitki najdeni pod kolišči inob njih na Ljubljanskem barju). Znanoje, da je bila na Rebri pod Ljubljanskimgradom v poznem srednjem vekulivarna zvonov in topov, Valvazor paje svoj znameniti kip Marije, ki še danesstoji na stebru pred Šentjakobskocerkvijo v Ljubljani, ulil pred dobrimitristo leti po svojem postopku v livarnimojstra Schlaga pred ljubljanskimiKarlovškimi vrati, kar je tudi bogatodokumentiral (Philosophical Transactions,London in Acta eruditorum, Leipzig).Tradicija livarstva pri nas očitnonikoli ni povsem zamrla, celo več:Slovenija je dandanašnji po proizvodnjiulitkov na prebivalca med prvimideželami na svetu, v Ljubljani pa sedajdeluje ena največjih livarn magnezija vsvetovnem merilu! Drobec v mozaiku– zdaj je to že zgodovina – slovenskegalivarstva je tudi Železniška livarnav Šiški (slika 1), kot se imenuje ta predelLjubljane.Kratka zgodovinaŽe kmalu po dograditvi Južne železnicese je pokazala potreba, da se vzdrževalnimobratom, ki so jih postavilisredi polja nasproti železniške postajev Šiški, priključi tudi livarna. Po nekaterihpodatkih se je to zgodilo letal868, ulivali pa so rdečo kovino (ventile,ohišja …) in skoraj gotovo prelivalidrsne ležaje (po ohranjeni in še vednodelujoči peči sodeč). Po prvi vojni oziromarazpadu Avstro-Ogrske monarhijeso livarno rdeče kovine preseliliv Maribor (ustno K. Rustja). Ker pase je pokazala potreba po sivi livarni(zavorni vložki ali zavornjaki, raznaohišja, rešetke kurišč za parne lokomotiveitd.), so v Šiški postavili kupolkov današnji Kalilnici oziroma Kovačijiin delo začeli leta 1920 (dimnik še stoji)(slika 2 ). Proizvodnja je rasla in jebilo treba misliti na novo stavbo, karse je zgodilo sredi druge vojne, in čeRMZ-M&G 2012, 59

Železniška livarna v Šiški445bi ta trajala še kak mesec dlje, bi Livarnaverjetno imela tudi fasado, pravijo.Sprva je bila v stavbi garaža zaželezniški avtopark in šele leta 1948je v njej stekla proizvodnja. Naslednjimejnik je leto 1978, ko je bila proizvodnjadeloma avtomatizirana. Gostol jedobavil konvejer in avtomatiziral pripravopeska. Ob koncu osemdesetih letpreteklega stoletja je proizvodnja dosegladobrih 3000 t letno (max. 3206t), z osamosvojitvijo pa sprva padla naokoli 1500 t, kasneje pa na dobrih 1000t raznih ulitkov. Dne 10. oktobra 2003je prišlo do težje obratne nesreče, karje bil dokončni povod za zaprtje Livarneteden dni kasneje (sicer so Livarnoskušali zapreti že od leta 1960 naprej),delavci pa so bili prerazporejeni podrugih obratih. Po dostopnih podatkihje Železniška livarna med svojim delovanjemproizvedla okoli sto tisoč tonulitkov iz sive litine (v najboljših časihveč kot 200 000 kosov raznih ulitkovna leto).Stroji in opremaDo modernizacije je delo v livarni potekalopretežno ročno, tako kot še danesv večini majhnih livarn (slika 3).Prvi formarski stroji so bili ročni. Z letise je oprema dopolnjevala, nabavljeniso bili prvi pnevmatski formarski stroji(foromat 10 , kasneje še 20, pnev-Slika 1. Železniška livarna v Šiški – pogled s severovzhodaRMZ-M&G 2012, 59

446 Lajovic, A.Slika 2. Izrez iz Situacijskega načrta Kr. drž. žel. Prve delavnice za stroje v Ljubljani(okoli leta 1920)RMZ-M&G 2012, 59

Železniška livarna v Šiški447matski livarski nabijači itd.). Notranjitransport je potekal na vozičkih po ozkotirnihprogah ob livarni in skozi njona ročni pogon. Na razpolago je bilo leeno mostno dvigalo, izgotovljene formepa so se zlagale v t. i. »štose« in»cvingale«.Do temeljitega preobrata je prišlo zrekonstrukcijo (na osnovi elaboratain pod vodstvom inž. Sergeja Jegliča)(slika 4). Škoda je le, da tedaj niso nabavililinije Disamatic, ki je bila v tistemčasu baje le nekaj dražja od vgrajenegapostrojenja, ki ga je projektiralin dobavil GOSTOL (Goriške strojnetovarne in livarna). Kakor koli že, srcelivarne je bila t. i. linija, sestavljena izšestih foromatov 10 (in nekaj več v rezervioziroma na popravilu), avtomatskepriprave peska, konvejerja in dvehkupolk, ki sta talili izmenoma. Manjšeserije raznih ulitkov se je, če je bilomogoče, formalo na liniji, sicer pa vt. i. ročni formariji, kot smo jo imenovali.Tu smo imeli dva foromata 20 alipa smo forme klasično ročno izdelali.Ulivalo se je na posebni valjčni progi.Slika 3. Železniška livarna pred rekonstrukcijo (1978)RMZ-M&G 2012, 59

448 Lajovic, A.Livne lonce smo na notranji straniizdelali z nabijalno maso (Kremen,Novo mesto), pred ulivanjem pasmo jih sušili in ogrevali s plinskimgorilnikom z odprtim plamenom (2kg plina na uro). Tudi modelne ploščena foromatih smo greli s podobnimi,le precej manjšimi plinskimigrelniki.Čistilnica je imela Gostolov čistilnioziroma peskalni stroj s kovinskoverigo, peskalo pa se je z jeklenimgranulatom povprečne zrnatosti 1mm (Muta), ter več brusilnih strojev.Uporabljali smo bakelitne brusneplošče za sivo litino (Comet, Zreče).Težava je bila le v tem, da je včasihkatero razneslo.Notranji transport kot tudi polnjenječistilnega stroja se je navadno opravilos posebej prirejenim 2,5-tonskimviličarjem.Pod livarno je spadala tudi izdelavakalupov za termitno varjenje tirnic.Za te kalupe (do 15 000 kompletov naleto), pa tudi za izdelavo raznih jederpo CO 2-postopku, smo uporabljalidva pnevmatska strelna stroja (vzhodnonemškiizdelek, tako kot foromati).Livarna je imela centralno odsesovalnonapravo. Ta je bila v bistvuprecej velik vodni sesalnik (60 kW),ki pa nam je delal velike težave zlastipozimi in nikoli ni kaj prida delovalzaradi premajhne kapacitete. Kasnejeje bil zamenjan z vrečastim filtrom,ki za temperaturne razlike sicer nibil bistveno občutljiv, pač pa za dež.Montirali so nam ga namreč pod kap,elektronika za krmiljenje izpihovanjavreč pa v takih razmerah rada odpoveoziroma pride do prebojev. Podobenfilter, le precej manjši (15 kW) in starejši,je bil nameščen ob čistilnici inje odsesaval prah iz čistilnega in brusilnihstrojev. Ta je imel pnevmatskokrmiljenje izpihovanja, ki pa je pozimiprerado zmrznilo.Originalna stresalna rešetka je bilaizjemno glasna. Delavec, ki je delalob njej, pa je bil na velikem prepihu,zato smo jo morali zamenjati z novo,boljše konstrukcije, in jo delno prilagoditinašim potrebam.Staro litino smo pripravljali za pretaljevanjev razbijalnici (okoli desetmetrov visok stolp z vitlom in okolitono težko kroglo) na posebni hidravličnipreši ali pa ročno s težkimikladivi.Pomemben del livarne je bila nekočmodelna mizarna, ki je bila relativnodobro opremljena in je imela zaposlenihveč mizarjev. Z leti so se potrebepo novih modelih tako zmanjšale, daso bila potrebna le še občasna manjšapopravila (kitanje, barvanje) obstoječih.Kovinske modele pa so tako žeod nekdaj izdelovali in vzdrževaliorodjarji, strugarji in rezkalci.RMZ-M&G 2012, 59

Železniška livarna v Šiški449Slika 4. Delo v livarni je bilo po rekonstrukciji v marsičem močno olajšano.Izdelava armatur za zavornjake je prvotnospadala k delavnici za izdelavorezervnih delov za železniška vozila,šele zadnja leta pa pod livarno. Armaturesmo izdelovali na ekscentričnihprešah, krivinski radij pa popravljaliročno na šabloni in s kladivom, sajso imeli materiali praviloma različnovzmetnost. Armature so morale bitipred vlaganjem v forme povsem čiste(brez škaje, maščob ali rje), sicer so sepojavile razne težave. Čistili smo jih vposebnem bobnu, kjer so se trle medseboj, bolj zapletene pa v čistilnemstroju. Prav zadnje leto obratovanjalivarne smo napravili novo petsteznoorodje za rezanje in luknjanje armatur.Za pogon pnevmatskih strojev smoimeli v Šiški centralno kompresorskopostajo s tremi kompresorji, in sicer:• več kot sto let star batni Ingersol--Randt (45 kW),• pol mlajši Spiros (90 kW),• še malo mlajši Fagram (90 kW).Navadno sta zadnja leta komprimiralazrak slednja dva – ali eden ali drugi,RMZ-M&G 2012, 59

450 Lajovic, A.Ingersol pa je bil zlata rezerva. Zrakaje bilo ob polni zasedenosti kapacitetv livarni ravno še dovolj. Po ukinitviproizvodnje v livarni pa so, kot kaže,tudi kompresorji imeli vsega dovoljin so drug za drugim »zaribali« alipa jih je celo razneslo. Na srečo brezhujših posledic.Inštalirana električna moč v livarni(vključno s kompresorsko postajo)je bila okoli 0,5 MW, seveda pa vsistroji navadno niso bili vklopljeniistočasno. Kljub temu pa je porabaelektrike na območju železniškihdelavnic v Šiški vztrajno rasla,kar je bila konec osemdesetih žeresna težava, poleg občasnih izpadovelektrične napetosti, seveda.Za pogon ključnih naprav v livarnise je v takih primerih (podpihkupolk, dvigala, razsvetljava, pripravapeska) uporabljal električniagregat Torpedo z avtomatskimvklopom (l50 kW), ki je bil (oziromaje še) nameščen ob kompresorjih.Za rezanje konic v porabi električneenergije na območju vsehdelavnic v Šiški pa je bil nabavljenračunalniški sistem, ki je v takemprimeru najprej izključil kalilnepeči (80 kW in 45 kW), potem pazaporedoma stružnice za kolesnedvojice (vsaka po 80 kW). No, potempa smo se osvobodili oziromaosamosvojili. Proizvodnja je padala,tozadevne težave pa so postalepreteklost …Delovni časV letih najintenzivnejše proizvodnjeso prvi delavci začeli delo okoli drugeure zjutraj (kurjenje kupolk, zalaganjepeči in priprava taline), ob šestih pa seje navadno že ulivalo. Glavnina je delalado dveh, bolj zagnani pa tudi še popoldne(navadno so ulivali t. i. »strojnolitino«, razkopavali forme, izdelovalikalupe itd.).V tistih letih nas je bilo v livarni zaposlenihdo 60 delavcev (vzdrževalnaskupina je bila posebej, določena delaso delali drugi obrati – armature naprimer), fluktuacija pa velika. Z osamosvojitvijoso se razmere korenitospremenila. Potrebe po naših proizvodihso se v nekaj letih prepolovile. Prilagajalismo se na vse mogoče načine.V začetku devetdesetih let smo najprejspremenili delovni čas tako, da smovsi začeli delati ob šestih, litina pa jebila na žlebu ob deseti uri, sčasoma pasmo morali tudi ta urnik prilagoditi šezmanjšanim naročilom. Leta 2003 jebilo v livarni zaposlenih še 24 delavcev(skupaj z vzdrževalcema), ulivali pasmo vsak drugi delovni dan, dan brezulivanja pa smo porabili za vsa drugadela, ki jih je bilo treba opraviti – npr.pripraviti litino, jedra, forme, armature,očistiti in obrusiti ulitke, popravitistroje itd. Da nam je uspelo z relativnomajhnim številom delavcev vse to postoriti,je bilo mogoče zato, ker nam jez leti uspelo delno mehanizirati notra-RMZ-M&G 2012, 59

Železniška livarna v Šiški451nji transport (posebno prirejen viličarza polnjenje čistilnega stroja), uredititransportne poti (betoniranje, asfaltiranje)in notranji transport zmanjšatina najmanjšo mogočo mero ali ga celoeliminirati (pnevmatsko polnjenje silosovz novim peskom), z uporabo novihmaterialov (termobeton pri obzidavikupolk, keramični filtri idr.), z optimiranjemulivnih sistemov in na splošnoz zmanjšanjem izmeta ter seveda s stalnoskrbjo za mehanizacijo, vključno sskrbjo, da so bili vitalni rezervni delivedno na zalogi. In ne nazadnje – vlivarni smo uvedli skupinski dopust,ker drugače enostavno ni šlo oziromane bi imelo smisla. Za kolikor tolikosinhrono delovanje livarne je bila namrečpotrebna neka minimalna zasedba.Zadnja leta smo zadostno številodelavoljnih delavcev zagotavljali prekBiroja za delo.Beneficirana delovna doba se je z letikrajšala in je bila ob zaprtju livarnedva meseca na dvanajst mesecev za rednozaposlene delavce v proizvodnji.Pečarji, ki so vzdrževali kupolke, sobili zaradi izjemnih delovnih razmerprosti, ko je bilo delo opravljeno. Talilciso v osemdesetih letih delali vsakdrugi delovni dan (imeli so precej podaljšandelavnik zaradi popoldanskegaulivanja, potem pa so morali še pospravitipod pečmi), zadnja leta pa soimeli le še dodatek v urah glede na ure,prebite ob kupolkah. Podoben dodatekso imeli tudi tisti delavci, ki so ulivali,vendar le na ure, prebite pri ulivanju.Prvotno so se nadure izplačevale (vlivarni jih je bilo tudi več kot 10 000na leto), zadnja leta pa so se pravilomalahko le izkoristile.KadriV vseh teh letih so šle skozi livarnostotine delavcev, večinoma brez izobrazboali z njo, livarjev pa je bilorelativno malo. Vzrok je bil verjetnotudi v tem, da so metalurgi prišli vvodstvo Livarne šele konec sedemdesetihlet, in pa splošna miselnost, ki jelivarje, njihovo znanje, delo in znojpodcenjevala. Relativno slabe plačeso seveda na kvaliteto dela posrednoslabo vplivale. Po osamosvojitvi seje položaj korenito spremenil. Mnogodelavcev je odšlo in kljub zmanjšaniproizvodnji smo morali zaposlitinove, vsak delavec pa je moral obvladatipo več delovnih mest. In takose je zgodilo, da je Livarna imela pridobrih tridesetih zaposlenih kar petmetalurških tehnikov. Od teh so trijedelali v proizvodnji, kjer so imeliše vedno višjo plačo kot v prejšnjislužbi. Žal jim nismo mogli ponuditinjihovi izobrazbi primernih delovnihmest, niti plače. Z leti je vseh petpostopoma odšlo. Eden je odšel nasvoje in ima doma sivo livarno (JaniKopač), drugi pa v razne službe, ki sstroko niso imele nič skupnega.RMZ-M&G 2012, 59

452 Lajovic, A.Med delavci, ki so bili zaposleni v našilivarni, ni ravno veliko znanih ljudi, pavendar. Eden med njimi je narodni herojTine Rožanc. Po poklicu je bil čevljar.Dobrih dvajset let je delal v našilivarni, in to je bila tudi njegova prva,edina in zadnja služba. Kot občinskiodbornik v Pirničah, kjer je bil doma,je bil tudi skrbnik osirotelega StanetaRozmana, kasnejšega legendarnegakomandanta.Drugi, Metod Trobec, ima povsem drugačensloves. Njegov tedanji nadrejenije vedel povedati, da je bil to edini delavec,ki se ga ni dalo spraviti v red. Nasrečo v livarni ni bil dolgo …KlimaNaša livarna je imela to srečo, da jebila zgrajena še po starih, preizkušenihvzorih. Prvotno je bila dolga okoli40 m, široka 15 m in visoka dobrih20 metrov. Kasneje je bila podaljšanaproti severu in dodanih je bilo več večjihali manjših prizidkov ter napuščev,tako rekoč okoli in okoli livarne. Zlatavreden je bil nadstrešek z loputamiskoraj čez celo sleme na strehi livarne.Lopute smo poleti odprli, čez zimo paso bile zaprte. Z leti smo odsesavanjein s tem ventilacijo v obratu z raznimivrati, zasloni in podobnim precej dobrouredili, tako da se je le redko zgodilo,da se zaradi dima ali prahu v zrakuni videlo skozi livarno. Dimne plineokoli kupolk, ki so se sproščali zlastipri odtakanju žlindre in so bili precejnadležni ter nikakor ne zdravilni, smoodsesavali kar z ventilatorjem za podpihpeči, ki je bil nameščen v prvemnadstropju ob kupolkah.Izjemno vroča poletja zadnjih let sonas spodbudila k razmišljanju o hlajenjustrehe, o adiabatnem hlajenju livarne(podobno kot je v uporabi na kurjihfarmah) in še čem (na »air condition«tako ni imelo smisla niti pomisliti). Dorealizacije hlajenja ni prišlo, pa smozato tedaj, ko je zunanja temperaturapresegla 27 °C tri dni zapored in se jelivarna dodobra razgrela, začeli deloob četrti uri zjutraj in delali do dvanajsteure, da smo nekako preživeli. Kasneje,ko prometne zveze tega niso večomogočale, pa smo delali od šestih dodvanajstih. Podoben je bil prehod nazajna običajen delovni čas.Huje pa je bilo pozimi. Snovalci odpraševanjaso namreč pozabili na temeljnopravilo ventilacije, pa tudi klimatizacije,namreč, če hočeš iz nekega prostorazrak odsesavati, ga moraš vanj tudidovajati. Tega slednjega pa ni bilo. Intako so nam marsikatera na tračnicahnad podbojem obešena drsna vrata pozimistala postrani, skozi vsako špranjov zidu pa je vleklo. Prvotno prav v osrednjemprostoru livarne ni bilo pravekurjave in zlasti po vikendih, še bolj papo daljših praznikih, ko so se litine nakonvejerju in peči ohladile, smo imeliRMZ-M&G 2012, 59

Železniška livarna v Šiški453z zagonom proizvodnje neizmerne težave.Imeli smo sicer dva termogena(po 6 kg goriva na uro), ki pa v hudemmrazu nista zadoščala, razen tega sta izznanih razlogov bolj ogrevala strehokot pa samo livarno. Hidravlično oljese je zgostilo, forme so primrznile napalete, uteži na forme, voda v ceveh paje zmrznila, včasih je katero tudi razneslo.Zrak oziroma klima v livarni pa jebila odlična, le precej mrzlo je bilo.EkologijaNajvečja težava večine livarn so dimniplini ter prah različnega izvora, in minismo bili nobena izjema. Prah iz proizvodnje(stresalna rešetka, pripravapeska, čistilni stroj itn.) nam je z letiuspelo dobro očistiti z vrečastimi filtri.Težje je bilo ta problem rešiti pri kupolkah.Sprva so se kape na njih samohladile, voda iz vodovoda pa je različnovelike prašne delce spirala v peskolovnejame, od tod pa je tekla v kanalizacijo.Včasih se je je tudi kaj prelilo.Povečane zahteve glede dovoljeneemisije prahu (vse drugo je bilo vdovoljenih mejah) so zahtevale spremembokonstrukcije kap na kupolkah.Namestili smo novo visokotlačno črpalko,na kapah smo namestili vences posebnimi šobami, odpadno vodo panapeljali v 60 kubičnih metrov velikoodsluženo železniško cisterno, ki smojo postavili ob livarni. V njej se je vodaumirila, pepel se je usedel na dno cisterne,očiščena voda pa je šla nazaj včrpalko. Prvotno je k vsej napravi spadalše ciklon in polž za iznašanje usedliniz njega. Zaradi prevelikih težav vzimskem času in zmanjšanja proizvodnjesmo ciklon kasneje opustili in jevoda tekla kar direktno v cisterno. Tosmo morali očistiti nekajkrat na leto. Inso prišle nove zahteve: še manj prahuv dimnih plinih. V tem primeru bi bilverjetno edini izhod ohlajanje dimnihplinov in filtriranje preko vreč, vendarse nam s tem problemom že ni bilo trebaveč ukvarjati, ker so nam livarnoprej zaprli.Razen jeder, izdelanih s CO 2-postopkom,drugih problematičnih materialovzavestno nismo uporabljali, niti jihskušali uvesti v proizvodnjo. Količineodpadnih peskov in prahu iz filtrov paso bile znatne in so tako rekoč dnevnopotovale na deponijo Barje (prvotnopovprečno po en zabojnik na dan, kasnejeustrezno manj).Varstvo pri deluZadnja leta nas je bilo že tako malo, daje večina delavcev v enem delovnemdnevu delala najmanj na dveh delovnihmestih. Zjutraj se je na primer delalo v»štancariji«, potem pa se je pripravljalovložek in zalagalo peč, kar pomenidiametralne klimatske razmere, kar jebilo nevšečno zlasti pozimi. Zato jeRMZ-M&G 2012, 59

454 Lajovic, A.imel vsak delavec najmanj dve delovniobleki, od tega vsaj eno podloženoza zimske razmere, več parov delovnihčevljev, pa tudi škornjev, saj se jemarsikaj dogajalo, kot že omenjeno,ne samo v livarni, pač pa tudi okoli njena prostem, med lužami, snegom in šečim. Zagovarjali smo stališče, da je primernadelovna obleka in obutev mnogocenejša kot kakršna koli bolniška.Res, zgodilo se je celo, da v livarni celmesec ni bil nihče bolan!Nabava takih zaščitnih sredstev je biltežji problem. Vedno se je našel kdo,ki je rad »šparal«, pa naj stane kolikorhoče. Do zadnjega je bilo treba kar naprejprepričevati odgovorne za nabavo,da delovni čevlji s plastičnim podplatomne spadajo v livarno, da morajobiti šivani, usnje kvalitetno, podplat pagumijast z izrazitim profilom, potemše, da delovne bluze, hlače in pajaci tercelo vezalke na čevljih ne smejo bitiizdelani iz plastičnih materialov, da nivseeno, kakšna so zaščitna očala (poškodbeoči so bile v čistilnici oz. pridelu na brusnih strojih relativno pogoste),da večnih težav z zaščitnimi rokavicaminiti ne omenjamo (porabili smojih res veliko).Opeklinam se v livarnah zaradi naravedela ne da izogniti. Na srečo se opekline,ki so posledica brizgov sive litine,nasprotno od aluminija, zdravijo relativnohitro. Večinoma ni bilo hudega,težjih poškodb je bilo le nekaj. Najtežjanesreča je bila brez dvoma tista, ki seje zgodila 10. oktobra 2003 in je posledičnotudi povzročila zaprtje livarne.(Mimogrede – vsa čast in slava reševalcemz Reševalne postaje Ljubljana.Prvi, z motorjem, je bil v Livarni že nekajminut po nesreči, drugi, z avtomobilom,pa le nekaj kasneje). Zanesljivopa do nesreče ne bi prišlo, če bi livnodvigalo tedaj že imelo radijske komande,za kar pa smo si zaman prizadevali.Organizacija proizvodnjeV časih največje proizvodnje v osemdesetihletih so bili v vodstvu Livarnepoleg obratovodje (v tistem času so bilito metalurgi Vilijem Pobežin, RatkoMatić, Jože Golob, Ratimir Branica inzadnjih slabih dvajset let Aleš Lajovic)zaposleni še:• poslovodja talilnice in čistilnice(Anton Bizjan),• poslovodja ročnega in strojnegaformanja (Franc Tomažič),• normirec (Janez Dolničar) in• administratorka (Ivanka Križelj).Skupinovodje so delali v proizvodnji,skupine pa so štele do deset delavcev.Dela in dolžnosti na posameznih delovnihmestih so bile dokaj točno opredeljene,kot je bilo tedaj v navadi, naželeznici pa še posebej. V osemdesetihletih je bila fluktuacija delavcev v neposredniproizvodnji, kot smo takratrekli, izjemno velika. Nemalo delavcevRMZ-M&G 2012, 59

Železniška livarna v Šiški455je vzdržalo v livarni samo po nekaj dni,tako da jih niti spoznati nismo utegnili,kaj šele, da bi si zapomnili njihovaimena in priimke. Tedaj so imeli zaposlenina železnici namreč proste karte,ki so veljale po celi Jugoslaviji, in takoje bilo v livarni zaposlenih kar nekajdelavcev celo iz Negotinske krajine(med sabo so se sporazumevali v romunskemjeziku). Nekateri še danes živijov Ljubljani. Sicer pa je bila livarnaJugoslavija v malem. In ker so delavcipo vikendih prihajali na delo pogosto znočnimi vlaki z nedelje na ponedeljek,so garderobe ob ponedeljkih, bolj kotne, spominjale na Kosovo polje po bitki,proizvodni rezultati pa so bili temuprimerni. In če k navedenemu dodamoše to, da so pravoslavni prazniki okolištirinajst dni kasneje kot katoliški, tempa prištejemo še muslimanske, dobimopopolno sliko dogajanja. Praznovali paso se načeloma vsi in praznovali so vsi.Marsikje je še danes tako.V časih, ko je livarna obratovala vsedelovne dni v letu in še kakšnega zraven(tedaj so bile moderne delovne sobote,pa razne solidarnostne delovnesobote itn.), je bil remont navadno enkratna leto, praviloma junija (kasnejeso imeli gospodje vzdrževalci namrečpoletne počitnice) in je trajal od petkaod 14. ure do naslednjega ponedeljkado 6. ure zjutraj, delalo pa se je vse dnipo 12 ur. Postoriti je bilo treba marsikaj,med drugim tudi podreti talilni delkupolk, jih na novo pozidati itd. Zagonpo remontu je bil navadno mučen inpoln presenečenj, kar je trajalo še nekajnaslednjih delovnih dni.Tako kot vzdrževanje je bila tudi nabavnain skladiščna služba organiziranana nivoju Šiške, kar je bilo v tistihčasih razumljivo, enako tudi prodaja.Imeli smo tudi svojo skupino električarjev,ki so imeli v livarni tiste čase karprecej posla, kasneje pa so se potrebetudi na tem področju toliko spremenile(tudi izboljšale), da smo jih poklicali leše takrat, ko je bilo to potrebno.Proizvodni programPo rekonstrukciji se je velika večinaproizvodnje (več kot 90 %) odvijala naliniji z okvirji s svetlim prerezom 400mm × 500 mm in višino 165 mm. Dimenzijaje bila izbrana glede na potrebeželeznice po t. i. zavornjakih. To so biliizmenljivi torni vložki, navadno na vsakemkolesu po dva, pa tudi več, dolgi sobili od 200 mm do 450 mm, večinomas prerezom 65 mm × 80 mm in so imelizelo različno geometrijo. V okvirjihso bili od enega do štirje ulitki s skupnomaso med 20 kg in 35 kg. Glavninaproizvodnje v osemdesetih letih je bilapet tipov zavornjakov v skupni količiniokoli 200 000 kosov letno (+/–). Priročnem formanju so bile serije bistvenomanjše, letno pa se je v proizvodnji zvrstilookoli 300 pozicij za najrazličnejšapodjetja, ki so se ukvarjala s strojegra-RMZ-M&G 2012, 59

456 Lajovic, A.Slika 5. Izdelki Železniške livarne v Šiški na sejmu v Beogradu (v 80. letih prejšnjegastoletja)dnjo: SCT, Gradis, Itas, Mlinostroj,Elan, IMP, Turboinštitut, Litostroj, Iskraitn. Najtežji ulitki so tehtali do dve toni(kobilice za Elanove barke, pa tudi sicerse je za to tovarno veliko ulivalo – predvsemrazne uteži za dviganje. Zadnjavelika pošiljka – 60 t – je šla v Libijo).Predvsem po zaslugi Litostroja – Tovarnečrpalk pa so naši izdelki raztreseni povsem svetu (slika 5).LitinaOsnovno sestavo litine je določal jugoslovanski,kasneje pa evropski železniški(UIC) standard. Razlika je bila lev tem, da se je količina fosforja z letidvignila z 0,8 % na 1 % (s tem pa tuditorni količnik in posledično vse drugo).Ogljika je bilo okoli 3,3 %, silicija okoli2,0 %, mangana med 0,5 % in 0,8 %,žvepla okoli 0,1 % in bakra približno0,3 %. Povprečna trdota litine je bila180 HB, s povišanjem masnega deležafosforja pa 210 HB. Načeloma smo sedržali v bližini Sc = l. Natezna trdnosttake litine je bila okoli 245 N mm –2 ,kar je tudi za splošno strojegradnjopovsem zadoščalo, pa tudi obdelovalnostje bila praviloma odlična (razen vnekaterih redkih, zelo specifičnih pri-RMZ-M&G 2012, 59

Železniška livarna v Šiški457merih). Ulivali smo tudi zavornjake spovečano količino fosforja (2,5 % in stem višjim tornim koeficientom) za Hrvaškeželeznice. Tam so namreč na nekaterihodsekih začeli voziti z višjimihitrostmi, zaustavna oziroma zavornapot pa je morala ostati enaka.Nekoč so imeli v naši livarni navado,da so ob koncu taljenja pripravili t. i.strojno litino (brez fosforja) in z njoulivali razne izdelke za zunanje naročnike,ostanek pa zlili v forme z zavornjaki.Rezultati pri zaviranju s takimizavornimi vložki niso bili spodbudni(pri prenizkem fosforju namreč zavornjakiradi »zaribajo«, treba je biloponovno stružiti kolesa, njihova trajnostnadoba se je skrajšala itd.), zato seje ta praksa ukinila, naročnike pa obvestilo,da je na voljo le še »železniška«litina. Praktično ni bilo nikogar, ki biga ta sprememba motila iz takih alidrugačnih razlogov. Naj še omenimo,da je »železniška« litina korozijsko relativnodobro obstojna, nepeskana paskoraj povsem.SurovineOsnovni surovini vsake sive livarnesta, ob stari litini seveda, koks in surovoželezo, poleg njiju pa še kvalitetenkremenov pesek ustrezne granulacije inbentonit. Koks smo nekoč dobivali izkoksarne v Lukavcu (z leti je bil vednoboljši), kasneje iz Bakra (uvoz iz Brazilije),na koncu pa smo ga nabavljaliprek podjetja TERMO iz Škofje Loke(v bistvu je bil iz vseh vetrov, vendarkvaliteten). Vmes je bilo nekaj epizods češkim in poljskim koksom. Zlastislednji nam je povzročal silne preglavice,saj žlindra ni in ni hotela iz peči.Je bil pa poceni. Podobno je bilo s poljskimgrodljem, kjer so se pojavljali šenekateri nenavadni dodatni problemi vstrukturi, in sicer pod površino ulitkovin na njej. Navadno smo dobivali grodeljiz Vareša in nekaj iz Štor, občasnokako pošiljko iz Rusije, Češke in šeod drugod. Zadnja leta smo vse surovoželezo kupovali pri že omenjenemTermu, kjer izdelujejo kameno volnoin imajo v bistvu obrnjen proizvodniproces kot v sivih livarnah. Njih zanimažlindra, ki jo predejo in naprej predelujejov izolacijske materiale, surovoželezo pa je za njih odpadek. V našemprimeru je ta odpadek koristen, saj imaprecej fosforja in silicija, tako da smododajali potrebne ferolegure praktičnole za korekcijo kemične sestave. Težavosmo imeli le s tem, da so pol letav Škofji Loki pretaljevali amfibolit(Avstrija), potem pa diabaz (Hrvaška),surovo železo iz obeh talin pa je bilona istem kupu, vendar z zelo različnokemično sestavo.Bentonit nam je desetletja dobavljalaINA, Kutina, (prav tako livarsko črnino– inakol) in na kvaliteto nismo imelipripomb. Vmes je bilo le nekaj kratkihepizod z bentomakom (Makedonija), kiRMZ-M&G 2012, 59

458 Lajovic, A.pa se ni najbolje izkazal (prevelik raztrosin relativno slaba tlačna trdnost).Prvotno so se v naši livarni uporabljalipeski podjetja KREMEN, Novo mesto,s povprečno zrnatostjo 0,16 mm in z,za naše potrebe, ne najboljšo prepustnostjo.Ker je bil povprečen perlitnirob na ulitkih debel okoli 0,2 mm, vprimeru zavornjakov pa je bilo želeno,da elementarni ogljik, ki je izločen vlitini v obliki lističev oziroma rozet, prizaviranju čim prej začne mazati, smoprešli na moravški pesek, in sicer nafrakcijo s povprečno granulacijo 0,25mm, da je bila površina ulitkov primernovalovita. Ko so pri TERMITU vMoravčah dokončno uredili separacijoin je bila mogoča dostava sušenega peskas cisterno, smo se rešili marsikatereskrbi in nadležnega ročnega prekladanja.Tudi pri proizvodnji kalupov zatermitno varjenje tirnic smo prešli namoravški pesek, potem ko je licenčnapogodba s podjetjem Elektrotermit,Essen, potekla (prej smo pesek na njihovozahtevo vozili iz Lipika, Hrvaška).Le oljna jedra za zavornjake smoše naprej izdelovali z novomeškim peskom– delež neizprane gline nam je vtem primeru prišel kar prav. Površinalukenj v ušesih zavornjakov, skozi katerese zabije vzmetna zagozda, ki držizavornjake na nosilcu, in so izdelane stakimi jedri, je zelo gladka, čeprav smojedra, če se je mudilo, v te namene izdelovalitudi po CO 2-postopku in z moravškimpeskom. Z vodnim steklom zata postopek in z raznimi dodatki za razpadjeder po litju so bile ciklične težave,ne glede na to, kje smo ga naročaliin v kakšni embalaži je bil. Včasih smopa tudi sami kaj dodali.Z leti nam je uspelo doseči, da so seizrabljeni zavornjaki vračali v livarno(ti imajo povprečno še tretjino masein so bili za nas optimalen in cenovnonajugodnejši vložek). Potrebno starolitino smo dobivali prek Surovine inDinosa. Ker se njim tedaj to še ni zdelopotrebno, smo jo lomili sami ali vrazbijalnici, ali na posebni hidravličnipreši (zavorne bobne npr.), ali na rokos težkimi kladivi.Ferolegure smo nabavljali večinomav domačih logih in gajih (Eksoterem,Termit), z izjemo ferofosforja, ki smoga dobivali iz Avstrije.CeneTiste čase so se povprečne cene zavornjakov(tudi evropske) navadno gibaleokoli ene nemške marke za kilogram(približno pol današnjega evra). Ulitke,ki smo jih formali ročno, smo prodajalitrikrat draže, pa tudi več, če je bil kosbolj kompliciran (npr. rotorji za centrifugalnečrpalke). Ceno smo določali zavsak ulitek posebej, glede na potrebnovloženo delo, serijo itn.Po zaprtju naše livarne leta 2003 je začelaželeznica kupovati zavornjake vItaliji (Fonderie Pisano, Salerno). Itali-RMZ-M&G 2012, 59

Železniška livarna v Šiški459jani so prej kot v letu dni dosegli povišanjecene približno za petino, kasnejepa še precej več. Kasneje se je cenaumirila na okoli 1,2 EUR/kg. Mi smotak razvoj dogodkov tako ali tako predvideliglede na vse, kar se nam je dogajalov tistih letih. Koliko so se stroškiželeznici z zaprtjem livarne povečali,se da izračunati brez posebnih težav.Letna poraba zavornjakov v Slovenijije okoli dobrih tisoč ton. (Podobno potkot izdelava zavornjakov je šla že predleti izdelava kalupov za termitno varjenjetirnic in še kaj.)Prodaja Livarne je bila v letu 1995 756572 EUR (181 305 000 SIT), od tegazavornjaki 1378 t oz. pribl. 684 500EUR (164 mio. SIT), ročno formanje56 t oz. pribl. 684 360 EUR (15 mio.SIT), obloge za termitno varjenje tirnic4731 parov oz. pribl. 62 593 EUR (2mio. SIT). Zaloga je s 15 t narasla na140 t. Celotna proizvodnja je bila takov tem letu 1580 t.V tem letu nas je bilo v Livarni zaposlenih35 delavcev, dobrega pol leta pasmo imeli še dva zaposlena prek birojaTabela 1. Nabava materialov in drugi stroški Livarne v letu 1995Vrsta blaga oz. storitve Količina Cena/SIT Znesek/SIT Znesek/EURKoks 362 t 29,97 10 862 926 63 900Surovo železo (termo) 170 t 19,90 3 383 000 19 900Surovo železo (uvoz) 21 t 24,40 512 400 3 014Stara litina 470 t 17,31 8 133 040 47 841Zavornjaki (povrat) 608 t 18,84 11 454 720 67 381Masa Natural (poprav. peči) 83 t 13,46 1 117 180 6 572Masa NMG 3 19 t 21,56 415 676 2 445Bentonit 48 t 26,49 1 271 520 7 480Inakol (liv. črnina) 1 t 20,05 20 050 118Ferosilicij 12 t 65,46 785 520 4 621Ferofosfor 6 t 333,92 2 003 520 11 785Visk 12 t 130,77 1 582 317 9 308Armature 13 379 079 78 700Elektrika 400 000 KW 22,82 9 128 000 53 694Odvoz smeti 250 kont. 7000,00 1 750 000 10 294Plače v Livar 40 000 000 235 294Investicije (rešetka) 900 000 5 294Analize 460 8000,00 4 140 000 24 353Mestno zemljišče 1 000 000 5 882Razno 15 000 000 88 235S K U P A J 126 839 027 746 112RMZ-M&G 2012, 59

460 Lajovic, A.za delo. Promet na zaposlenega v Livarnije bil okoli 35 000 EUR.V tabeli 1 je prikazana nabava materialovin drugi stroški Livarne v letu1995.Kontrola kvaliteteKemijske in mehanske lastnosti našihlitin so desetletja preiskovali v litostrojskihlaboratorijih, prav tako metalografijo,in to v skupno zadovoljstvo.Vzorce smo dostavljali v Litostroj enkrattedensko – za vsak delovni dan,ko se je ulivalo po enega. Sprva smožagali naključno izbrane zavornjake, kiso šli v izmet, npr. zaradi porušene geometrije,in na njih opravili vse potrebneraziskave, redno tudi metalografske(zanimala nas je predvsem debelinaperlitne plasti na robu ulitka, razporeditevgrafita itd.). Ko so se pojavilikvantometri, smo na vsak delovni dan,ko se je ulivalo, pripravili po en vzorecza kemično analizo na tej napravi inpo en vzorec (razrezan zavornjak) nateden za druge raziskave. Če je kvalitetazanihala, so bile raziskave sevedapogostejše, kar pa je bilo le redko potrebno.Po potrebi so nam v Litostrojuizdali tudi ateste, saj so bili za to pooblaščeni.Posel je bil dodobra utečen,osebje laboratorijev pa seznanjeno tudiz našo problematiko, in če je bilo treba,so nam šli zelo na roko. Eno takihpodročij je bilo ulivanje zavornjakovs povišanim fosforjem. Zadnja leta ješel razvoj preiskovalnih metod že takodaleč, da smo lahko imeli rezultate kemijskeanalize v obratu že v dobri uripo ulitju (vmes je bilo treba vzorce zakvantometer dostaviti v Litostroj). Razumljivoje, da smo večkrat razmišljalio svojem laboratoriju, vendar se namračun nikakor ni hotel iziti. In smoostali pri storitvah Litostroja – kot žepovedano – v skupno zadovoljstvo.Pač pa smo v livarni izvajali dnevnoobratno kontrolo, tako vizualno kot tuditrdote ulitkov, mehanskih lastnosti zavornjakov(padalno kladivo) in peskov.Laboratorij za peske je imel letnico izdelave1955 in je bil izdelan v Budimpeštipo licenci Georga Fisherja. Prvihtrideset let je srečno prebil v skladišču,ker očitno ni bilo nikogar, ki bi hotel aliznal delati z njim. S prihodom novihmoči v proizvodnjo smo ga aktivirali,izdihnil pa je skupaj z livarno (aparaturaza merjenje tlačne in strižne trdnostilivarskega peska, peč za določitev točkesintranja pa že mnogo prej).V zvezi s problematiko »zaribavanja«železniških koles pri zaviranju je bilonapravljenih več raziskav (prof. I. Kosovinc)brez jasnih odgovorov, ker jihdejansko tudi ni moglo biti. Vzrokovtovrstnih poškodb je namreč lahko več:od povsem subjektivnih (premočnozaviranje ali prehitro speljevanje) dobolj ali manj objektivnih – npr. okvarna avtomatiki pnevmatskih zavornihRMZ-M&G 2012, 59

Železniška livarna v Šiški461naprav itn. Rezultat je bil v večini primerovenak: Kolo se začne v pasu, kjerje najbolj obremenjeno, to je tam, kjerteče po tračnici, topiti (navadno je tapas širok okoli 20 mm), staljen materialpa se odlaga na zavornjaku v tankihlističih, debelih od 0,1 mm do 0,2 mm.Pri nadaljnjem zaviranju prihaja do trenjaenakih materialov, ki nujno preide vtorno taljenje, seveda spet kolesa, ker jenapetostno bistveno bolj obremenjenokot zavornjaki. Problematika je kompleksna,rešitev navadno zapletena, česploh je, in so si na železnici domisliligenialne rešitve: dežurnega krivca. Nenadomaso bili za vse take poškodbekrivi nekvalitetni zavornjaki oziromalivarna. Na srečo so tako rekoč vse ekspertize,ki so bile opravljene v zvezi sto problematiko, ugotavljale, da je z zavornjakivse v najlepšem redu in da jetreba vzroke za navedene poškodbe iskatidrugje. Načeloma pa je treba vsaktak primer obravnavati individualno.Sicer pa so bili atesti uporabljenih materialovin naših izdelkov arhivirani zadesetletja nazaj, vsak zavornjak pa jeimel ulit datum izdelave.TehnologijaNa liniji smo uporabljali enotni peseks povprečno zrnatostjo 0,25 mm, le izjemomatudi bolj finega, modelnega,kadar in če je bilo to potrebno (npr. zapekače!). Večina jeder je bila izdelanaiz oljnega peska (z raznimi dodatki –interna receptura) ter pregreta in ohlajenapred vlaganjem v forme. Jeder, izdelanihpo CO 2-postopku, smo na linijiuporabljali malo ali čim manj iz znanihrazlogov. Drugače je bilo pri ročnemformanju, kjer smo zadnja leta uporabljaliskoraj izključno le CO 2-jedra. Netako daleč nazaj je bila izdelava jederzapleten postopek, ki je zahteval obiloprakse in velike peči, kurjene z drvmiin premogom oz. koksom. V naši livarnismo tak način dela opustili srediosemdesetih let, v pečeh pa smo imeliskladišča modelov in materiala.Z leti je pri ulivnih sistemih prišlo doneprimernih ali celo škodljivih poenostavitev.Marsikdaj se je ulivni kanalopustil, saj je bila tako forma hitreje izdelana(včasih pa tudi prostora ni bilo).Ulivalo se je v takem primeru direktnov napajalnik, ki je bil navadno tudi predimenzioniran.In če livarji tudi nosuponovc niso dobro očistili (uporabljalismo ponovce s sifonom, pred tem panavadne lonce), kar ni bilo tako redko,so bili rezultati pričakovani – prevelikizmet oziroma potrebna popravila. Sprstom se je kazalo drug na drugega inje bilo zato včasih v poslovodski pisarniže kar precej vroče. Eden od razlogovje bil brez dvoma ta, da so bili livarjiglede na druge delavce v podjetjurelativno slabo plačani in precej več somorali delati (interna norma v obratu jebila okoli ene tone premetanega materialana uro dela).RMZ-M&G 2012, 59

462 Lajovic, A.Sredi osemdesetih let je bila situacija vlivarni taka, da se je en mesec delalo,da se je pokril izmet (oziroma je bilakoličina izmeta identična z mesečnoproizvodnjo), zastojev zaradi okvar jebilo tudi za kak mesec, bolniške so biletako posebno poglavje, pritiski za povečanjeproizvodnje pa veliki. Celo vItalijo naj bi začeli izvažati zavornjake.Z Italijo, hvala bogu, ni bilo nič, ker bisi obratovodstvo v tedanjih razmerahs tem poslom zelo verjetno polomilozobe.Zmanjšanja izmeta smo se lotili tako,da smo začeli dnevno kontrolirati livarskepeske (previsoke vlage niso bilenobena redkost) in s postopno zamenjavoulivnih sistemov, in sicer s takimi,ki so onemogočali, da bi žlindrakakor koli prišla v ulitke. Pri ročnemformanju smo izdelali elemente ulivnegasistema (sestavljali smo jih skorajkot lego kocke). Zopet se je ulivaloskozi ulivni kanal, iz njega je litinatangencialno pritekla v napajalnik, kise je v tem primeru rabil kot centrifugaSlika 6. Ulivni sistem s centrifugalnimi napajalniki – za zavornjaka od 2 × 10 kg na kosdo 13 kg na kosRMZ-M&G 2012, 59

Železniška livarna v Šiški463za odstranjevanje žlindre, in se prelilav livno votlino (slika 6). Po končanemlitju se je napajalnik posulo z livarskimpeskom, leta kasneje pa z eksotermnimposipom, kadar je bilo to potrebno alipa se je sploh uporabilo zaprte napajalnike.S pojavom keramičnih filtrovsmo začeli uporabljati tudi te, vendar lepri ročnem formanju. Uporabljali smojih v primeru, ko napajalnik ni bil potrebenin pri zelo zahtevnih ulitkih.Pri velikoserijski proizvodnji smo senajprej lotili tistih modelnih plošč, kjerje bilo največ izmeta, seveda. Navadnoje bilo treba plošče samo poravnati,sicer pa izdelati nove (uliti, žariti, obdelati).Modeli so bili večinoma bronasti,pa tudi naša »železniška« litinase je v te namene odlično obnesla, lenekoliko bolj krhka je bila. Navadnosta bila v formi po dva ulitka zavornjakov(včasih trije – dva vzporedno,tretji prečno). Ulivali smo skozi ulivnikanal, ki je bil na vrhu razširjen, karsmo napravili s t. i. vzmetno glavo,ki se je nasadila na nastavek za ulivnikanal pred formanjem, po njem pa seje izvlekla iz forme. V spodnjem deluforme se je ulivni kanal razcepil na dvadela, vsak kanal pa je litino dovedel vnapajalnik tangencialno. Tu se je litinapri ulivanju zavrtela, nato pa prelila vlivni votlini (od tod pa lahko še v tretjo,če je bila taka razporeditev na plošči).Napajalniki so bili zaprti in konični,saj so se rabili tudi kot kompenzatorza sunke, ki lahko dvignejo zgornji delforme in nastanejo v trenutku, ko selivne votline zapolnijo (ferodinamičnitlaki, ki so lahko seveda bistveno večjiod ferostatičnih). Napajalnik je imelv naši livarni torej trojno vlogo: svojoosnovno, v njem se je litina očistila inkompenziral je sunke, ki nastanejo pripolnjenju forme z litino (avtor podpisani).Seveda do končnih rezultatovnismo prišli takoj. Malo se je računalo,malo žagalo ulitke in ulivne sisteme,pa malo spremenilo ali dopolnilo itn.Vsak ulitek oziroma vsaka konfiguracijana modelni plošči ima namreč svojezahteve. Kjer je bilo mogoče, smotak ulivni sistem uporabili tudi v ročniformariji (namesto filtrov, ki kljub vsemupomenijo strošek).Prvotno se je ulivalo tako, da je zavornjak»ležal« v formi (z ušesom navzdol),kar je bilo ugodno tudi zato, kerse je laže vložilo jedro in armatura (Toje navadno, očiščeno železo, večinomaz dimenzijami 5 mm × 20 mm inpoljubno dolžino, ki preprečuje, da zavornjakob eventualnih udarcih, ki sepojavljajo pri eksploataciji, razpade.Armature so lahko včasih zelo komplicirane,posebno pri visokofosfornihzavornjakih). Težava pa je bila v tem,da so se vse eventualne napake nakopičilev zgornjem delu forme oziroma na»delovni« ploskvi zavornjaka – torejtam, kjer je to v našem primeru najmanjprimerno. To je bil tudi razlog, da smovse zavornjake od tedaj naprej ulivaliz ušesom, jedrom in armaturo v zgor-RMZ-M&G 2012, 59

464 Lajovic, A.njem delu forme. Našo livarno smo sicerzaprli, modelne plošče za izdelavozavornjakov pa prodali, in menda ševedno »laufajo« nekje v Srbiji (baje vUžicu). Sicer pa je bila naša livarna posplošnem mnenju najboljša za izdelavozavornjakov v Jugoslaviji (v naši bivšidržavi se je tedaj letno porabilo med10 in 15 tisoč tonami zavornjakov; mismo jih ulili 3 tisoč).Vzdrževanje in izboljšaveVzdrževanje mehanizacije in razna popravilaso nam vzeli veliko časa, trudain energije, saj praktično ni bilo dneva,da ne bi kje kaj zaškripalo oziromase pokvarilo. Vzroki so bili včasihprav banalni, npr. slaba ali nikakršnahigiena pri vzdrževanju. Zato smo vsestroje, preden so šli v popravilo, najprejtemeljito, oziroma kolikor se je ledalo, oprali. Ležaj na disku za izmetavanjepeska iz mešalnika, na primer,nam je v povprečju vzdržal tri tedne,zamenjava pa ni bila nič kaj prijetnoopravilo. Toliko časa smo se ukvarjali stem problemom, da smo na koncu menjavalisamo še diske, pa še te le zeloredko, rezervni ležaji pa so nabirali rjoin prah v skladišču. Pa sploh niso bilipoceni! Na splošno smo si poskušalisami pomagati, če se je le dalo. Tunam je bil v veliko pomoč tako rekočgenialni str. tehnik Franc Turk, ki jemarsikatero napravo malone sam izumil,pa ne samo v livarni, temveč tudipo drugih obratih tedanjega Podjetja zavzdrževanje voz in strojev v Šiški, kije delovalo v okviru železnice (ŽG).Eden takih dosežkov je konstrukcijapremičnega podvozja na traktorjih, kiomogoča vožnjo tudi po tirih in s tempremik železniških vozil v okviru podjetja,čiščenje snega po tirih itd. Takoopremljenih traktorjev smo v Šiškiizdelali nekaj deset (in se še izdelujejo),svoj delež pa je tu prispevala tudilivarna. Vse te izboljšave so med drugimprivedle do tega, da je bila našemupodjetju podeljena plaketa zlato sonce,ki je bila za časa Jugoslavije najvišjepriznanje za inovativne dosežke. Sevedabrez razumevanja tedanjega vodstvapodjetja za naše eksperimente (ki nisobili vedno uspešni), nam ne bi uspelokaj dosti napraviti; zasluga gre zlastiinž. Ivanu Mediču.Livarna je v tistem času dobila novnadstrešek na južni strani, kjer smoimeli skladišče ulitkov, potem novoskladišče za ferolegure in druge materiale,ki smo jih potrebovali pri vsakdanjemdelu, ter za rezervne dele. Livarnaje tedaj dobila tudi novo kritino, saj jestara že izdatno puščala na vseh koncihin krajih. To je bil tudi edini resnejšigradbeni poseg v samo stavbo livarne vvsej njeni zgodovini. Prekrivali pa smoseveda – le kdaj neki? Sredi decembra,med snežnimi meteži in v hudem mrazu.Ob razkriti strehi je spodaj v livarnitekla proizvodnja, delavci smo kihali,kaj hujšega pa na srečo le ni bilo.RMZ-M&G 2012, 59

Železniška livarna v Šiški465Sicer pa so marsikatera opravila v zveziz livarno tako ali drugače v vsej njenizgodovini potekala pod vedrim nebom,v snegu in dežju, na pripeki alimrazu – tako priprava vložka, ki je bilado zadnjega skoraj povsem ročno opravilo,transport okoli livarne in še marsikaj.Livarna je bila tudi zadnji obratv Šiški, ki je dobil centralno kurjavo,pa še to ne v celoti. Tako rekoč za vsakposamezen radiator se je bilo potrebnoboriti. Vsa prepričevanja, da se z zmrznjenimlivarskim peskom ne da delati,niso kaj dosti zalegla. Podobno je bilos transportnimi potmi. Še sredi osemdesetihlet so bile okoli livarne tako rekočpovsod same jame, luže in blato, patudi v sami livarni tlaki marsikje nisobili urejeni. Dokazovanje in prepričevanje,da je daleč največ transporta vpodjetju v livarni in okoli nje, je dalorezultate šele čez leta. Zadnje površinesmo zabetonirali šele neposredno predzaprtjem, in sicer lastnoročno delavcilivarne. Kaj hočemo. Tako je, žal, bilo.Borili smo se do zadnjega diha … Nekateriv vodstvu železnice pa so se zadovoljilis tem, da so nam z užitkommetali polena pod noge. Čim več, če jele bilo mogoče!EpilogPrav neverjetno je, s čim vse so namgrenili življenje. Na vse mogoče načineso skušali doseči, da se livarna zapre.Eden od teh načinov je bil tudi ta, da jebil objavljen javni razpis za dobavo zavornjakov,in to kljub temu, da je imelaželeznica svojo livarno! Po nekaj poizkusihoziroma razpisih se je končnonašel pravi dobavitelj: Fonderie Pisanoiz Salerna v Italiji. Tja je nemudomaodhitel tedanji direktor železniškegaCentra za nabavo s svojo sodelavko,kasneje pa še najmanj ena veččlanskadelegacija. Obratovodjo Železniškelivarne za vsak primer niso povabili sseboj. Lahko bi se kaj zakompliciralo!Med tem v livarni nismo sedeli križemrok. Čim so nam prišli v roke prvi kosizavornjakov iz Italije, smo jih temeljitopregledali in dali v analizo. Rezultatiso bili tako glede geometrije kot kemijenegativni. Da ne govorimo o tem, kajbi napravili z nami, če bi v našem obratuizdelovali take zavornjake! Tako pavse tiho je bilo. Nesreča v livarni je prišlakot naročena. Livarno smo zaprli inposel teče nemoteno dalje.Na pobudo ravnatelja Železniškegamuzeja Mladena Bogiča smo o deluv livarni posneli okoli štiri ure filmskegamateriala. Nekatere kadre smoposneli samo poskusno, ker pa nas jenesreča prehitela in jih ni bilo mogočeponovno posneti, so bili v filmu uporabljeni.Na digitalno kamero je tedanjedogajanje posnel in potem gradivozmontiral, opremil z glasbo, zvokomin nekaterimi komentarji PrimožOzvald. Avtor je po poklicu strojni inženir,sicer pa velik ljubitelj železnice.RMZ-M&G 2012, 59

466 Lajovic, A.Enourni film je marsikomu zelo všečin je odličen dokument vsakodnevnegautripa v livarni in dogajanja ob njenemzapiranju.Zadnje dni smo v livarni, poleg podpisanega,preživeli:• Franko Barukčić, talilec, livar, brusilec,strojni formar,• Šimo Barukčić, strojni formar, brusilec,kovač, polnilec kupolk,• Jozo Deronja, talilec, livar, voznikviličarja, delavec na čistilnem stroju,brusilec, strojni formar in še kaj,• Gojko Gostimirović, strojni formar,izdelovalec jeder in armatur, pripravljavecpeska,• Marijan Horvat, strojni formar, izdelovalecarmatur, odgovoren tudiza kurjenje in zalaganje kupolk,• Marjan Ihanc, strojni in odličenročni formar (veliki ulitki),• Jožko Jesenovec, delavec pri rešetkiin v čistilnici, nabavljavec malice,• Andrija Jurić, pripravljavec peska,strojni formar, odgovoren tudi zadvig okvirjev na konvejer ter za rešetko,• Ivanka Križelj, administratorka,• Tomo Lapornik, strojni formar, izdelovalecarmatur, odgovoren tudiza zalaganje kupolk, sicer pa po poklicustrugar in strojni tehnik,• Marko Mavec, strojni in ročni formar,• Tone Novak, skupinovodja, strojniformar, jedrar, izdelovalec armatur,• Andrej Obreza, vzdrževalec,• Blaž Perković, talilec, livar, brusilec,• Iztok Petrle, izjemno agilen poslovodja,skladiščnik in nasploh »deklicaza vse«,• Milenko Petrović, livar, voznik viličarja,delavec pri čistilnem stroju,brusilec, zalagalec kupolk,• Nada Pranjić, jedrarka,• Zoran Simić, pečar, livar, strojniformar, brusilec, zalagalec kupolk,• Aleš Skopec, vzdrževalec, orodjar,odgovoren tudi za dvig okvirjev nakonvejer ter za rešetko,• Drago Slijepčević, odgovoren zadvig okvirjev na konvejer, izdelovalecarmatur, strojni formar,• Alojz Štupar, pečar, strojni formar,brusilec, zalagalec kupolk, izdelovalecarmatur,• Pero Tokić, pečar, livar, brusilec,zalagalec kupolk in• Miodrag Zdravković, talilec, livar,brusilec, zalagalec kupolk.In danes ?Stavba Livarne še stoji. Stroje in raznoopremo se je prodalo, če je le bilo mogoče.Konvejer in pripravo peska sorazrezali in prodali na odpad, prav takolivarske formarske stroje (foromate).Pisarne so deloma izropali, pohištvo,kar ga je ostalo, je šlo v Moste, dokumentacijaLivarne skupaj z arhivom pav kontejner.RMZ-M&G 2012, 59

Železniška livarna v Šiški467Pod kupolko, s katero smo talili zadnjidan, smo pustili podložni koks in nažlebu žlindro. Druga kupolka pa je ševedno pripravljena za taljenje, le prižgatijo je treba.Izdelavo raznih ulitkov, ki smo jih nekočizdelovali za potrebe železnice,pa tudi nekaj drugih pozicij je prevzelnekdanji poslovodja v Livarni Jani Kopačin jih sedaj izdeluje v svoji livarniv Vikerčah pod Šmarno goro (ohišja zapritlikave signale, razne rezervne deleza lokomotive, vagone itn.).Za stavbo Livarne se zanima Tehniškimuzej Slovenije, saj naj bi v njejuredil avtomobilski oddelek, enako sezanima tudi za bivšo upravo, da bi tjapreselil svojo. Skupaj z Železniškimmuzejem, ki že domuje v Šiški, in nekaterimiobrati, ki so še v uporabi –recimo kovačijo, bi tako na prostorunekdanjega Podjetja za vzdrževanjevoz in strojev v Šiški lahko dobili lep,zanimiv in zaokrožen muzejski kompleks.Prispevek je posvečen prelitemu znojulivarjev v Železniški livarni v Šiški.ViriArhiv Železniške livarne v ŠiškiLastna opažanja in zapisiReisp, B. (1987): Korespondenca J. V. Valvasorjaz Royal Society, SAZURustja, K.: Članki na temo zgodovine železnice,posebej delavnic v Šiški, objavljeniv več številkah in letnikih revijeNova progaSkupina avtorjev (1972): Metalurški priročnik,TZSSkupina avtorjev: Livarski priročnikStruna, A. (1955): Vodni pogoni na Slovenskem,TMSRMZ-M&G 2012, 59

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RMZ – Materials and Geoenvironment, Vol. 59, No. 4, pp. 469–470, 2012469Društvo alumnov diplomantov Oddelka za materialein metalurgijoTradicija ohranjanja stikov med diplomanti in Oddelkom za materiale inmetalurgijo (OMM) traja že vrsto let in seveda ni namenjeno le obujanjuspominov na študijska leta, temveč tudi zagotavljanju poklicne strokovne inkarierne povezanosti, izmenjavi dobrih praks med diplomanti, študenti in OMM,hkrati pa predstavitev uspešnih posameznikov, ki s svojim delom dvigujejo tudiugled izobraževalne institucije, kjer so pridobili izobrazbo.Na ustanovnem občnem zboru 23. 10. 2012 je bilo ustanovljeno Društvoalumnov OMM – društvo diplomantov Oddelka za materiale in metalurgijoNaravoslovnotehniške fakultete Univerze v Ljubljani.Z ustanovitvijo Društva alumnov OMM želimo stkati trdne vezi med študenti,diplomanti in prijatelji OMM. Njegove dejavnosti bodo:• vzpostaviti in negovati povezanost in komunikacijo kot krepitev vezi meddiplomati vseh generacij;• negovati pripadnost diplomantov šoli;• aktivno sodelovanje pri razvoju metalurške stroke;• promocija dosežkov članov društva;• prispevati k večji prepoznavnosti diplomantov tako doma kot v tujini, vjavnem in zasebnem sektorju;• ustvarjati in spodbujati sodelovanje med člani Društva alumnov OMM ingospodarskimi subjekti ter drugimi družbenimi institucijami;• zagotoviti možnost sodelovanja diplomantov pri razvijanju novihizobraževalnih programov;• prispevati k osebnemu in strokovnemu razvoju posameznikov in organizacij;• aktivno sodelovanje pri razvoju družbe;• diplomantom omogočiti druženje in povezovanje.Delovanje Društva alumnov OMM bo odvisno predvsem od vašega sodelovanja.Mnoge med vami spremlja zgodba o uspehu. Delite jo z drugimi člani klubaali z bodočimi diplomanti in soustvarjajte njihovo karierno pot. V Društvualumnov OMM lahko delujete kot predavatelji, vodite okrogle mize, prispevatečlanek ali novice, pomagate pri organizaciji alumnidogodkov ali sponzoriratealumnidogodke. Vsaka pomoč in ideja bosta dobrodošli. Vaše cenjeneEvent notes

470 Medved, J., Rosina, A., Vončina, M.komentarje, predloge in pobude pošljite na:http://www.ntf.uni-lj.si/omm/index.php?page=static&item=1225.Slika 1. Ustanovni zbor Društva alumnov Oddelka za materiale in metalurgijo Univerzev Ljubljani 23. 10. 2012Članstvo v društvu je prostovoljno.Član društva lahko postane vsak, ki je uspešno končal kateri koli javno veljavniprogram izobraževanja, ki ga izvaja ali ga je izvajal Oddelek za materiale inmetalurgijo Naravoslovnotehniške fakultete Univerze v Ljubljani ali organizacija,ki je pravni prednik te fakultete. Članstvo v društvu se začne s podpisom pristopneizjave, v kateri podpisnik izjavi voljo, da postane član društva in navede letodiplome, magisterija oz. doktorata ter izjavi, da dovoljuje društvu vpogled vevidenco diplomirancev fakultete. Če iz evidence diplomirancev fakultete nirazvidno, kateri javno veljavni program izobraževanja je končal prijavitelj,odloči o članstvu upravni odbor po izvedenem postopku, v katerem se ugotovi,ali prijavitelj izpolnjuje pogoje za pridobitev članstva.Društvo ima redne, častne ter pridružene člane.Člani društva so lahko tudi pravne osebe, ki zaposlujejo diplomante fakultete.Jožef Medved, Andrej Rosina, Maja VončinaRMZ-M&G 2012, 59

Author’s Index471Author`s Index, Vol. 59, No. 4Adagunodo T. A.Adewale AkinmosinAkinola Oluwatoyin O.Bibik I. P.Dervarič EvgenKos AndrejKugler GoranLajovic AlešMartins Osei M.Medved JožefOladejo O. P.Olafisoye E. R.Olawale Osinowo O.Peruš IztokRosina AndrejShemetov P. A.Sunmonu L. A.Talabi Abel O.Terčelj MilanTurk RadoVončina Majataadagunodo@yahoo.comI.Bibik@cru.ngmk.uzevgen.dervaric@ntf.uni-lj.sikos@marmorsezana.comgoran.kugler@omm.ntf.uni-lj.siales.lajovic@gmail.comjozef.medved@omm.ntf.uni-lj.siwale.osinowo@mail.ui.edu.ngsoar_abel@yahoo.commilan.tercelj@omm.ntf.uni-lj.siRado.Turk@ntf.uni-lj.simaja.voncina@omm.ntf.uni-lj.siRMZ-M&G 2012, 59

472 Author’s IndexAuthor`s Index, Vol. 59Adagunodo T. A.Adamović DraganAdewale AkinmosinAkinola Oluwatoyin O.Alijagić JasminkaAndjelov MišoBavec MilošBenedetti LucillaBibik I. P.Car MarjetaCerar SonjaDervarič EvgenDobnikar MetaEszter KalmanGodicelj TomažGosar AndrejGosar MatejaGupta S. K.Jamšek Rupnik PetraKores StanislavKos AndrejKovačič MihaKugler GoranKurbanov Abdirahim AhmedovichLajovic AlešMandić VesnaMartins Osei M.Medved JožefMikuž VasjaMrvar PrimožOladejo O. P.Olafisoye E. R.Olawale Osinowo O.Pavšič Jernejtaadagunodo@yahoo.comjasminka.alijagic@geo-zs.simiso.andjelov@gov.similos.bavec@geo-zs.siI.Bibik@cru.ngmk.uzevgen.dervaric@ntf.uni-lj.simeta.dobnikar@gov.siinfo@canterburyea.commateja.gosar@geo-zs.sipetra.jamsek@geo-zs.sistanislav.kores@ntf.uni-lj.sikos@marmorsezana.commiha.kovacic@store-steel.sigoran.kugler@omm.ntf.uni-lj.sibo_bosh@mail.ruales.lajovic@gmail.commandic@kg.ac.rsjozef.medved@omm.ntf.uni-lj.sivasja.mikuz@ntf.uni-lj.siprimoz.mrvar@omm.ntf.uni-lj.siwale.osinowo@mail.ui.edu.ngjernej.pavsic@ntf.uni-lj.siRMZ-M&G 2012, 59

Author’s Index473Peruš IztokRosina AndrejSharma AshokShemetov P. A.Shields DeborahSrikanth MadhulikaStefanović MilentijeStopar RobertStražar AlešSunmonu L. A.Šajn RobertŠarler BožidarŠebela StankaŠmuc AndrejŠolar SlavkoTalabi Abel O.Terčelj MilanTeršič TamaraTurk RadoUhan JožeUrbanc JankoVončina MajaVrabec MarkoZelič UrškaZupančič NinaŽivković Miroslavashok.mnit12@gmail.comDeborah.Shields@PoliTo.itstefan@kg.ac.rsrobert.sajn@geo-zs.sibozidar.sarler@ung.sisebela@zrc-sazu.siandrej.smuc@geo.ntf.uni-lj.sislavko.solar@geo-zs.sisoar_abel@yahoo.commilan.tercelj@omm.ntf.uni-lj.sitamara.tersic@geo-zs.siRado.Turk@ntf.uni-lj.sijoze.uhan@gov.sijanko.urbanc@geo-zs.simaja.voncina@omm.ntf.uni-lj.simarko.vrabec@geo.ntf.uni-lj.siurska.zelic@alianta.sinina.zupancic@ntf.uni-lj.siRMZ-M&G 2012, 59

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Contents475RMZ MATERIALS AND GEOENVIRONMENTContentsVolume 59, 2012/1, 2, 3, 459/1Particle swarm based batch filling schedulingKovačič, M., Šarler, B. 1Study of process parameters on Al-7.0 % Si-0.45 % Mg alloy casttrough strain induced melt activation techniqueSharma, A., Gupta, S. K., Srikanth, M. 19Investigation of ironing process depending on applied tool materialsand coatingsAdamović, D., Mandić, V., Terčelj, M., Stefanović, M., Živković, M. 27Contribution of Mn content on the pressure dose propertiesMedved, J., Godicelj, T., Kores, S., Mrvar, P., Vončina, M. 41Structural research of Uzbekistan basaltsKurbanov, A. A. 55In-situ determination of the earth pressure at rest in overconsolidatedclayKalman, E. 7159/2/3ForewordBrenčič, M. 99Osemdeset let življenja in dela Dragice StrmoleDobnikar, M. 101RMZ-M&G 2012, 59

Contents476Phase contrast method for asbestos fibres determinationDobnikar, M. 103Osemdeset let življenja in dela profesorja geologije dr. Rajka PavlovcaMikuž, V., Pavšič, J. 109Ostanki peresastih koral iz eocenskih plasti pri Gračišću blizu Pazinav IstriMikuž, V., Pavšič, J. 113Osemdeset let življenja in dela zaslužnega profesorja geologije dr.Simona PircaZupančič, N. 123Regionalna porazdelitev geokemičnih prvin v tleh SlovenijeAndjelov, M. 125Mercury enrichments in soils influenced by Idrija mercury mine,SloveniaGosar, M., Teršič, T. 141Cooperation of GeoZS in geochemical investigation in former YugoslaviaŠajn, R., Alijagić, J. 159Sustainable Aggregates Resource Management: experience learntand shared within South East EuropeŠolar, S., Shields, D., Zelič, U. 181Data-driven modelling of groundwater vulnerability to nitrate pollutionin SloveniaUhan, J. 201RMZ-M&G 2012, 59

Contents477Hydrochemical characteristics of groundwater from theKamniškobistriško polje aquiferUrbanc, J., Cerar, S., Stražar, A. 213The influence of vegetation type on metal content in soilsZupančič, N. 229Sedemdeset let življenja in dela profesorja geologije dr. JožetaČarjaVrabec, M. 245Geophysical evidence of recent activity of the Idrija fault, Kanomlja,NW SloveniaBavec, M., Car, M., Stopar, R., Jamsek, P., Gosar, A. 247Characteristics of the Predjama fault near Postojna, SW SloveniaŠebela, S. 257Middle to Upper Jurassic succession at Mt Kobariški Stol (NWSlovenia)Šmuc, A. 267Evidence of Quaternary faulting in the Idrija fault zone, Učja canyon,NW SloveniaVrabec, M. 285Geomorfni indikatorji kvartarne aktivnosti Savskega preloma medGolnikom in PreddvoromJamšek Rupnik, P., Benedetti, L., Bavec, M., Vrabec, M. 299RMZ-M&G 2012, 59

Contents47859/4Calculation of stress-strain dependence from tensile tests at hightemperatures using final shapes of specimen’s contoursKugler, G., Terčelj, M., Peruš, I., Turk, R. 331Petrochemical characteristics and geotechnical properties of crystallinerocks in the archean-proterozoic terrain of Ijero-Ekiti,Southwestern NigeriaAkinola, O.O., Talabi, A. O. 347The groundwater potential evaluation at industrial estate Ogbomoso,Southwestern NigeriaSunmonu, L. A., Adagunodo, T. A., Olafisoye, E. R., Oladejo, O. P. 363Physicotechnical substantiation of parameters of blasting operationsin deep open pit minesShemetov, P. A., Bibik, I. P. 391Geophysical and sedimentological studies for reservoir characterizationof some tar sands deposits in southwest NigeriaAdewale, A., Olawale, O. O., Martins, O. M. 413Izbira tehnološkega procesa in opreme za pridobivanje naravnegakamna v kamnolomu LipicaKos, A., Dervarič, E. 429Železniška livarna v Šiški 443Lajovic, A.Društvo alumnov diplomantov Oddelka za materiale in metalurgijoMedved, J., Rosina, A., Vončina, M. 469RMZ-M&G 2012, 59

480 Instructions to authors• Preliminary notes represent preliminary research findings, which shouldbe published rapidly.• Professional papers are the result of technological research achievements,application research results and information about achievements inpractice and industry.Short papers (the number of pages is limited to 1 for Discussion of papers and2 pages for Publication note, Event note and In Memoriam). No abstract isrequired for short papers.• Publication notes contain author’s opinion on new published books,monographs, textbooks, or other published material. A figure of coverpage is expected.• Event notes in which descriptions of a scientific or professional eventare given.• Discussion of papers (Comments) where only professionaldisagreements can be discussed. Normally the source author(s) reply theremarks in the same issue.• In memoriam (a photo is expected).Supervision and review of manuscripts. All manuscripts will be supervised.The referees evaluate manuscripts and can ask authors to change particularsegments, and propose to the Editor the acceptability of submitted articles.Authors can suggest the referee but Editor has a right to choose another. Thename of the referee remains anonymous. The technical corrections will bedone too and authors can be asked to correct missing items. The final decisionwhether the manuscript will be published is made by the Editor in Chief.The Form of the ManuscriptThe manuscript should be submitted as a complete hard copy including figures andtables. The figures should also be enclosed separately, both charts and photos inthe original version. In addition, all material should also be provided in electronicform on a diskette or a CD. The necessary information can conveniently also bedelivered by E-mail.RMZ-M&G 2012, 59

Instructions to authors481Composition of manuscript is defined in the attached TemplateThe original file of Template is available on RMZ-Materials and GeoenvironmentHome page address:http://www.rmz-mg.comReferences - can be arranged in two ways:- first possibility: alphabetic arrangement of first authors - in text: (Borgne, 1955),or- second possibility: [1] numerated in the same order as cited in the text: example [1]Format of papers in journals:Le Borgne, E. (1955): Susceptibilite magnetic anomale du sol superficiel.Annales de Geophysique, 11, pp. 399–419.Format of books:Roberts, J. L. (1989): Geological structures, MacMillan, London, 250 p.Text on the hard print copy can be prepared with any text-processor. Theelectronic version on the diskette, CD or E-mail transfer should be in MS Wordor ASCII format.Captions of figures and tables should be enclosed separately.Figures (graphs and photos) and tables should be original and sent separately inaddition to text. They can be prepared on paper or computer designed (MSExcel,Corel, Acad).Format. Electronic figures are recommended to be in CDR, Al, EPS, TIF or JPGformats. Resolution of bitmap graphics (TIF, JPG) should be at least 300 dpi.Text in vector graphics (CDR, Al, EPS) must be in MSWord Times typographyor converted in curves.Color prints. Authors will be charged for color prints of figures and photos.Labeling of the additionally provided material for the manuscript should be veryclear and must contain at least the lead author’s name, address, the beginning ofthe title and the date of delivery of the manuscript. In case of an E-mail transferthe exact message with above asked data must accompany the attachment withthe file containing the manuscript.RMZ-M&G 2012, 59

482 Instructions to authorsInformation about RMZ-M&G:Editor in Chief prof. dr. Peter Fajfar (phone: ++386 1 4250-316) orSecretary Barbara Bohar Bobnar, univ. dipl. ing. geol. (phone: ++386 1 4704-630),Aškerčeva 12, 1000 Ljubljana, Sloveniaor at E-mail addresses:peter.fajfar@ntf.uni-lj.si,barbara.bohar@ntf.uni-lj.siSending of manuscripts. Manuscripts can be sent by mail to the EditorialOffice address:• RMZ-Materials & GeoenvironmentAškerčeva 12,1000 Ljubljana, Sloveniaor delivered to:• Reception of the Faculty of Natural Science and Engineering (for RMZ-M&G)Aškerčeva 12,1000 Ljubljana, Slovenia• E-mail - addresses of Editor and Secretary• You can also contact them on their phone numbers.These instructions are valid from August 2009RMZ-M&G 2012, 59

Instructions to authors483NAVODILA AVTORJEMRMZ-MATERIALS AND GEOENVIRONMENT (RMZ- Materiali ingeookolje) – kratica RMZ-M&G - je revija (ustanovljena kot zbornik 1952 inpreimenovana v revijo RMZ-M&G 1998), ki izhaja vsako leto v štirih zvezkih.V reviji objavljamo prispevke s področja rudarstva, geotehnologije, materialov,metalurgije, geologije in geookolja.RMZ- M&G objavlja izvirne znanstvene, pregledne in strokovne članketer predhodne objave samo v angleškem jeziku. Strokovni članki so lahkoizjemoma napisani v slovenskem jeziku. Kot dodatek so zaželene recenzijedrugih publikacij (knjig, monografij …), nekrologi In Memoriam, predstavitveznanstvenih in strokovnih dogodkov, kratke objave in strokovne replike načlanke objavljene v RMZ-M&G v slovenskem ali angleškem jeziku. Prispevkinaj bodo kratki in jasni.Avtorstvo in izvirnost prispevkov. Avtorji so odgovorni za izvirnost podatkov,idej in sklepov v predloženem prispevku oziroma za pravilno citiranje privzetihpodatkov. Z objavo v RMZ-M&G se tudi obvežejo, da ne bodo nikjer drugjeobjavili enakega prispevka.Vrste prispevkovOptimalno število strani je 7 do 15, za daljše članke je potrebno soglasjeglavnega urednika.Izvirni znanstveni članki opisujejo še neobjavljene rezultate lastnih raziskav.Pregledni članki povzemajo že objavljene znanstvene, raziskovalne alistrokovne dosežke na novem znanstvenem nivoju in lahko vsebujejo tudi druge(citirane) vire, ki niso večinsko rezultat dela avtorjev.Predhodna objava povzema izsledke raziskave, ki je v teku in zahteva hitroobjavo.Strokovni članki vsebujejo rezultate tehnoloških dosežkov, razvojnih projektovin druge informacije iz prakse.Recenzije publikacij zajemajo ocene novih knjig, monografij, učbenikov, razstav…(do dve strani; zaželena slika naslovnice in kratka navedba osnovnih podatkov- izkaznica).RMZ-M&G 2012, 59

484 Instructions to authorsIn memoriam (do dve strani, zaželena slika).Strokovne pripombe na objavljene članke ne smejo presegati ene strani inopozarjajo izključno na strokovne nedoslednosti objavljenih člankov v prejšnjihštevilkah RMZ-M&G. Praviloma že v isti številki avtorji prvotnega člankanapišejo odgovor na pripombe.Poljudni članki, ki povzemajo znanstvene in strokovne dogodke (do dve strani).Recenzije. Vsi prispevki bodo predloženi v recenzijo. Recenzent oceniprimernost prispevka za objavo in lahko predlaga kot pogoj za objavo dopolnilok prispevku. Recenzenta izbere Uredništvo med strokovnjaki, ki so dejavni nasorodnih področjih, kot jih obravnava prispevek. Avtorji lahko sami predlagajorecenzenta, vendar si uredništvo pridržuje pravico, da izbere drugega recenzenta.Recenzent ostane anonimen. Prispevki bodo tudi tehnično ocenjeni in avtorjiso dolžni popraviti pomanjkljivosti. Končno odločitev za objavo da glavni inodgovorni urednik.Oblika prispevkaPrispevek predložite v tiskanem oštevilčenem izvodu (po možnosti z vključenimislikami in tabelami) ter na disketi ali CD, lahko pa ga pošljete tudi prek E-maila.Slike in grafe je možno poslati tudi risane na papirju, fotografije naj bodooriginalne.Razčlenitev prispevka:Predloga za pisanje članka se nahaja na spletni strani:http://www.rmz-mg.com/predloga.htmSeznam literature je lahko urejen na dva načina:-po abecednem zaporedju prvih avtorjev ali-po [1] vrstnem zaporedju citiranosti v prispevku.Oblika je za oba načina enaka:Članki:Le Borgne, E. (1955): Susceptibilite magnetic anomale du sol superficiel.Annales de Geophysique; Vol. 11, pp. 399–419.RMZ-M&G 2012, 59

Instructions to authors485Knjige:Roberts, J. L. (1989): Geological structures, MacMillan, London, 250 p.Tekst izpisanega izvoda je lahko pripravljen v kateremkoli urejevalniku. Nadisketi, CD ali v elektronskem prenosu pa mora biti v MS word ali v ASCIIobliki.Naslovi slik in tabel naj bodo priloženi posebej. Naslove slik, tabel in celotnobesedilo, ki se pojavlja na slikah in tabelah, je potrebno navesti v angleškem inslovenskem jeziku.Slike (ilustracije in fotografije) in tabele morajo biti izvirne in priložene posebej.Njihov položaj v besedilu mora biti jasen iz priloženega kompletnega izvoda.Narejene so lahko na papirju ali pa v računalniški obliki (MS Excel, Corel, Acad).Format elektronskih slik naj bo v EPS, tif ali JPG obliki z ločljivostjo okrog300 dpi. Tekst v grafiki naj bo v Times tipografiji.Barvne slike. Objavo barvnih slik sofinancirajo avtorjiOznačenost poslanega materiala. Izpisan izvod, disketa ali CD morajo bitijasno označeni – vsaj z imenom prvega avtorja, začetkom naslova in datumomizročitve uredništvu RMZ-M&G. Elektronski prenos mora biti pospremljen zjasnim sporočilom in z enakimi podatki kot velja za ostale načine posredovanja.Informacije o RMZ-M&G: urednik prof. dr. Peter Fajfar, univ. dipl. ing. metal.(tel. ++386 1 4250316) ali tajnica Barbara Bohar Bobnar, univ. dipl. ing. geol.(tel. ++386 1 4704630), Aškerčeva 12, 1000 Ljubljanaali na E-mail naslovih:peter.fajfar@ntf.uni-lj.sibarbara.bohar@ntf.uni-lj.siPošiljanje prispevkov. Prispevke pošljite priporočeno na naslov Uredništva:• RMZ-Materials and GeoenvironmentAškerčeva 12,1000 Ljubljana, Slovenijaoziroma jih oddajte v• Recepciji Naravoslovnotehniške fakultete (pritličje) (za RMZ-M&G)Aškerčeva 12,1000 Ljubljana, Slovenija• Možna je tudi oddaja pri uredniku oziroma pri tajnici.Navodila veljajo od avgusta 2009.RMZ-M&G 2012, 59

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Template487TEMPLATEThe title of the manuscript should be written in bold letters(Times New Roman, 14, Center)Naslov članka (Times New Roman, 14, Center)Name Surname 1 , …. , & Name Surname X (Times New Roman, 12, Center)xUniversity of ..., Faculty of ..., Address…, Country ... (Times New Roman, 11,Center)*Corresponding author. E-mail: ... (Times New Roman, 11, Center)Abstract (Times New Roman, Normal, 11): The abstract should beconcise and should present the aim of the work, essential resultsand conclusion. It should be typed in font size 11, single-spaced.Except for the first line, the text should be indented from the leftmargin by 10 mm. The length should not exceed fifteen (15) lines(10 are recommended).Izvleček (Times New Roman, navadno, 11): Kratek izvleček namenačlanka ter ključnih rezultatov in ugotovitev. Razen prve vrstice najbo tekst zamaknjen z levega roba za 10 mm. Dolžina naj ne presegapetnajst (15) vrstic (10 je priporočeno).Key words: a list of up to 5 key words (3 to 5) that will be useful forindexing or searching. Use the same styling as for abstract.Ključne besede: seznam največ 5 ključnih besed (3–5) za pomoč priindeksiranju ali iskanju. Uporabite enako obliko kot za izvleček.Introduction (Times New Roman, Bold, 12)Two lines below the keywords begin the introduction. Use Times New Roman,font size 12, Justify alignment.RMZ-M&G 2012, 59

488 TemplateThere are two (2) admissible methods of citing references in text:1. by stating the first author and the year of publication of the referencein the parenthesis at the appropriate place in the text and arranging thereference list in the alphabetic order of first authors; e.g.:“Detailed information about geohistorical development of this zone canbe found in: Antonijević (1957), Grubić (1962), ...”“… the method was described previously (Hoefs, 1996)”2. by consecutive Arabic numerals in square brackets, superscripted at theappropriate place in the text and arranging the reference list at the end ofthe text in the like manner; e.g.:“... while the portal was made in Zope environment. [3] ”Materials and methods (Times New Roman, Bold, 12)This section describes the available data and procedure of work and thereforeprovides enough information to allow the interpretation of the results, obtainedby the used methods.Results and discussion (Times New Roman, Bold, 12)Tables, figures, pictures, and schemes should be incorporated in the text at theappropriate place and should fit on one page. Break larger schemes and tablesinto smaller parts to prevent extending over more than one page.Conclusions (Times New Roman, Bold, 12)This paragraph summarizes the results and draws conclusions.Acknowledgements (Times New Roman, Bold, 12, Center - optional)This work was supported by the ****.RMZ-M&G 2012, 59

Template489References (Times New Roman, Bold, 12)In regard to the method used in the text, the styling, punctuation and capitalizationshould conform to the following:FIRST Option - in alphabetical orderCasati, P., Jadoul, F., Nicora, A., Marinelli, M., Fantini-Sestini, N. & Fois, E. (1981):Geologia della Valle del’Anisici e dei gruppi M. Popera - Tre Cime di Lavaredo(Dolomiti Orientali). Riv. Ital. Paleont.; Vol. 87, No. 3, pp. 391–400, Milano.Folk, R. L. (1959): Practical petrographic classification of limestones. Amer. Ass.Petrol. Geol. Bull.; Vol. 43, No. 1, pp. 1–38, Tulsa.SECOND Option - in numerical order[1]Trček, B. (2001): Solute transport monitoring in the unsaturated zone of the karstaquifer by natural tracers. Ph. D. Thesis. Ljubljana: University of Ljubljana2001; 125 p.[2]Higashitani, K., Iseri, H., Okuhara, K., Hatade, S. (1995): Magnetic Effects on ZetaPotential and Diffusivity of Nonmagnetic Particles. Journal of Colloid andInterface Science, 172, pp. 383–388.Citing the Internet site:CASREACT-Chemical reactions database [online]. Chemical Abstracts Service, 2000,updated 2. 2. 2000 [cited 3. 2. 2000]. Accessible on Internet: http://www.cas.org/CASFILES/casreact.html.Texts in Slovene (title, abstract and key words) can be written by theauthor(s) or will be provided by the referee or by the Editorial Board.RMZ-M&G 2012, 59

490 TemplatePREDLOGA ZA SLOVENSKE ČLANKENaslov članka (Times New Roman, 14, Na sredino)The title of the manuscript should be written in bold letters(Times New Roman, 14, Center)Ime Priimek 1 , …, Ime Priimek X (Times New Roman, 12, Na sredino)XUniverza…, Fakulteta…, Naslov…, Država… (Times New Roman, 11, Center)*Korespondenčni avtor. E-mail: ... (Times New Roman, 11, Center)Izvleček (Times New Roman, Navadno, 11): Kratek izvleček namenačlanka ter ključnih rezultatov in ugotovitev. Razen prve j bo tekstzamaknjen z levega roba za 10 mm. Dolžina naj ne presega petnajst(15) vrstic (10 je priporočeno).Abstract (Times New Roman, Normal, 11): The abstract should beconcise and should present the aim of the work, essential results andconclusion. It should be typed in font size 11, single-spaced. Exceptfor the first line, the text should be indented from the left marginby 10 mm. The length should not exceed fifteen (15) lines (10 arerecommended).Ključne besede: seznam največ 5 ključnih besed (3–5) za pomoč priindeksiranju ali iskanju. Uporabite enako obliko kot za izvleček.Key words: a list of up to 5 key words (3 to 5) that will be useful forindexing or searching. Use the same styling as for abstract.Uvod (Times New Roman, Krepko, 12)Dve vrstici pod ključnimi besedami se začne Uvod. Uporabite pisavo TimesNew Roman, velikost črk 12, z obojestransko poravnavo. Naslovi slik in tabel(vključno z besedilom v slikah) morajo biti v slovenskem jeziku.Slika (Tabela) X. Pripadajoče besedilo k sliki (tabeli)RMZ-M&G 2012, 59

Template491Obstajata dve sprejemljivi metodi navajanja referenc:1. z navedbo prvega avtorja in letnice objave reference v oklepaju naustreznem mestu v tekstu in z ureditvijo seznama referenc po abecednemzaporedju prvih avtorjev; npr.:“Detailed information about geohistorical development of this zone can befound in: Antonijević (1957), Grubić (1962), ...”“… the method was described previously (Hoefs, 1996)”ali2. z zaporednimi arabskimi številkami v oglatih oklepajih na ustreznemmestu v tekstu in z ureditvijo seznama referenc v številčnem zaporedjunavajanja; npr.;“... while the portal was made in Zope [3] environment.”Materiali in metode (Times New Roman, Krepko, 12)Ta del opisuje razpoložljive podatke, metode in način dela ter omogoča zadostnokoličino informacij, da lahko z opisanimi metodami delo ponovimo.Rezultati in razprava (Times New Roman, Krepko, 12)Tabele, sheme in slike je treba vnesti (z ukazom Insert, ne Paste) v tekst naustreznem mestu. Večje sheme in tabele je po treba ločiti na manjše dele, da nepresegajo ene strani.Sklepi (Times New Roman, Krepko, 12)Povzetek rezultatov in sklepi.RMZ-M&G 2012, 59

492 TemplateZahvale (Times New Roman, Krepko, 12, Na sredino - opcija)Izvedbo tega dela je omogočilo ………Viri (Times New Roman, Krepko, 12)Glede na uporabljeno metodo citiranja referenc v tekstu upoštevajte eno odnaslednjih oblik:PRVA MOŽNOST (priporočena) - v abecednem zaporedjuCasati, P., Jadoul, F., Nicora, A., Marinelli, M., Fantini-Sestini, N. & Fois, E. (1981):Geologia della Valle del’Anisici e dei gruppi M. Popera – Tre Cime di Lavaredo(Dolomiti Orientali). Riv. Ital. Paleont.; Vol. 87, No. 3, pp. 391–400, Milano.Folk, R. L. (1959): Practical petrographic classification of limestones. Amer. Ass. Petrol.Geol. Bull.; Vol. 43, No. 1, pp. 1–38, Tulsa.DRUGA MOŽNOST - v numeričnem zaporedju[1]Trček, B. (2001): Solute transport monitoring in the unsaturated zone of the karstaquifer by natural tracers. Ph. D. Thesis. Ljubljana: University of Ljubljana2001; 125 p.[2]Higashitani, K., Iseri, H., Okuhara, K., Hatade, S. (1995): Magnetic Effects on ZetaPotential and Diffusivity of Nonmagnetic Particles. Journal of Colloid andInterface Science, 172, pp. 383–388.Citiranje spletne strani:CASREACT-Chemical reactions database [online]. Chemical Abstracts Service, 2000,obnovljeno 2. 2. 2000 [citirano 3. 2. 2000]. Dostopno na svetovnem spletu: http://www.cas.org/CASFILES/casreact.html.Znanstveni, pregledni in strokovni članki ter predhodne objave se objavijov angleškem jeziku. Izjemoma se strokovni članek objavi v slovenskemjeziku.RMZ-M&G 2012, 59