Dust Control Handbook for Industrial Minerals Mining and Processing

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performed. Short-term stockpiles could consist of product or material that is being storedtemporarily until it is used in a process. Surge piles are common short-term stockpiles.Open areas are self-explanatory as they are large barren areas.Dust can be generated from stockpiles and open areas by wind velocities that entrainmaterial into the air. The United States Department of Agriculture states that erosion willtake place when "the surface soil is finely divided, loose, and dry; the surface is smooth9and bare; and the wind is strong." As stated previously, wind speeds as low as 13 mphcan result in entrainment of material for small diameter material (0.10 mm) [Chepil 1958].Conversely, there are several factors that can reduce wind erosion:soil that contains stable aggregates or clods that are large and dense to resist winderosion;soil that is compacted, roughened, or kept moist;vegetated soil or soil covered by vegetative residue (for example, straw); andwhen wind velocity near the ground surface is reduced or eliminated [Chepil1958].These four factors translate to the four dust control measures that can be applied to bothstockpiles and open areas: surface roughness, water, coatings, and wind barriers. Water,coatings, and to some extent wind barriers are generally applicable to stockpiles, while allfour measures can be applied to open areas.Surface RoughnessSurface roughness is important in wind erosion from open areas, but less important forstockpiles. Generally, the rougher the surface the less wind erosion affects it. This is truefor both land plots containing vegetative stubble and bare surface plots. The roughness foreach type of plot is created by the amount and orientation of the stubble for the stubbleplots, and the amount of surface irregularities and large clods for the bare surface plot.The mechanisms for controlling wind erosion are to decrease the force of the wind on thesurface or to trap the eroding material with larger particles. Increasing the magnitude ofthe roughness for each plot can result in a decrease in soil erosion [Zingg 1951]. The bestdust control for open areas is to plant vegetation to cover the entire area. Typically thevegetation is a grass, clover, alfalfa, etc.One control measure for open areas is to roughen the surface by using chisels, such as thatprovided by a chisel-pointed cultivator (Figure 10.10) used in agriculture [Chepil andWoodruff 1955]. The depth of tilling should be 3 to 6 inches. If higher wind speeds areexpected then the depth should be increased to 8 to 14 inches. The objective of this tillingis to expose the rough large cloddy soil particles to the surface (Figure 10.11). The largeclods protect the smaller particle material from wind erosion [Woodruff et al. 1977]. Inorder for the clods to be truly effective, they must cover the majority of the surface. Thistillage also produces ridges and furrows which have the potential to reduce erosion 50–909Chepil, W.S., "Soil Conditions that Influence Wind Erosion." United States Department of AgricultureTechnical Bulletin No. 1195. June 1958. pg. 4.Haul Roads, Stockpiles, and Open Areas 259
percent [Fryrear and Skidmore 1985]. However, this method is considered to be atemporary emergency measure to be used as a last resort in controlling wind erosion inagricultural settings [Chepil 1958]. Additionally, for this method to be most effective, thetilling must be accomplished at right angles to the wind direction and completed slowly toprevent the large clods from disintegrating [Woodruff 1966].Figure 10.10. Chisel plow used for creating large clodsin open areas to reduce wind erosion.260 Haul Roads, Stockpiles, and Open Areas
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Report of Investigations 9689Dust C
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FUNDAMENTALS OF DUSTCOLLECTION SYST
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Minimizing Field Fits and Welds ...
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Recommendations for Proper Wet Dril
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CONTROL TECHNOLOGIES FOR FILLING 50
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Effective Filtration ..............
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ILLUSTRATIONSFigure 1.1. Relationsh
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Figure 3.2. The air and water flow
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Figure 9.5. Problem created by heat
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UNIT OF MEASURE ABBREVIATIONSUSED I
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Robert J. Franta, Quotation Enginee
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silica. Quartz is the most common s
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DUST CONTROL HANDBOOK FOR INDUSTRIA
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CHAPTER 1: FUNDAMENTALS OFDUST COLL
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The shape of particles affects how
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EXHAUST SYSTEMS DESIGNAll exhaust s
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stripping, which allows workers to
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When using the air quantities in Ta
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X = distance in feet from the face
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Checklist for Hood EffectivenessThe
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A major disadvantage of the high-ve
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A common misconception when designi
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Avoiding Mitered Elbows Greater Tha
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Figure 1.13. Depiction of the horiz
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Figure 1.14. Typical design of grav
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Baghouse CollectorsBaghouse dust co
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Table 1.2. Emission factors for cru
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Figure 1.17. Typical design of a me
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Reverse Jet (Pulse Jet) CollectorsR
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Figure 1.20. Cartridge collector wi
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Wet scrubbers are particularly adva
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Electrostatic precipitators normall
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may be related to specific applicat
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times. When considering the depth o
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Figure 1.25. Demonstration of how a
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Figure 1.26. A typical fan performa
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Fan TypesThere are two basic types
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Figure 1.30. Typical centrifugal fa
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Figure 1.32. Typical roof ventilato
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The vast majority of dust particles
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Table 2.1. Particle/droplet size in
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Air Atomizing NozzlesAir atomizing
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Hydraulic Flat Fan NozzlesFigure 2.
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for dust knockdown or suppression,
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Nozzle MaintenanceFigure 2.14. Typi
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Accidental DamageInadvertent harm t
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NDT Educational Resource Center, Io
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78 Wet Spray SystemsDUST CONTROL HA
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contains a piston which delivers ha
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produce an increase in the penetrat
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Dry DrillingDry drilling is accompl
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Circular ShroudIn contrast to the u
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The collector airflow has a more su
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Air-Blocking ShelfThe air-blocking
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dust emissions from mast lowering,
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This simple procedure of creating a
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Figure 3.15. Air ring seal used to
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Figure 3.17. Illustrations showing
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unsubstantiated due to the inconsis
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safety considerations may preclude
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Figure 3.22. A filtration unit, loc
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Miller S, Emerick JC, Vogely WA [19
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USBM [1995]. The reduction of airbo
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110 Drilling and BlastingDUST CONTR
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Wet Control MethodsPREVENTION AND S
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Figure 4.2. Examples of compressive
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Figure 4.5. Illustration of a dry (
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Figure 4.6. Illustration of a dry (
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Wet dust control methods for crushi
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Work Practices to Minimize Dust Exp
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Some specialty grinding operations
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should be frequently inspected for
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Open screen decks slowly to allow i
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CHAPTER 5: CONVEYING AND TRANSPORTT
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Figure 5.3. Basic depiction of mate
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that the material falls before land
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Figure 5.10. Skirtboard used within
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CarrybackMaterial that sticks or cl
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CONVEYOR DESIGN AND MAINTENANCE ISS
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Figure 5.15. Conveyor transfer encl
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High-volume, high-pressure sprays s
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Figure 5.19. Depiction of a bucket
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Figure 5.21. Depiction of two types
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Figure 5.25. Venturi eductor utiliz
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CHAPTER 6: BAGGINGThis chapter disc
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caused during manufacturing, includ
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Overall PerforationsThe use of over
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Figure 6.5. Open-top bag being load
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Bagging operators should be aware t
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Figure 6.8. Exhaust hood to capture
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In the original design, a single no
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The OASIS is a relatively simple de
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Figure 6.13. Bag storage shelves sh
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Figure 6.14. Bag and belt cleaner d
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other industrial application using
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The robotic arm automatic palletize
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For many years, this plastic wrappi
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warehouse location until a later ti
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used successfully to perform this c
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CHAPTER 7: BULK LOADINGDuring the b
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Figure 7.2. Loading spout discharge
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Cascading Loading SpoutFigure 7.5 i
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a seal at the entry and exit points
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REFERENCESBiere G, Swinderman RT, M
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200 Bulk LoadingDUST CONTROL HANDBO
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many years, as well as some new and
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Figure 8.2. Air spray manifold desi
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Figure 8.3. Test subject wearing po
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Page 239 and 240: epetitive dust leaks should not sim
Page 241 and 242: Effective Upward Airflow PatternThe
Page 243 and 244: Figure 8.8. Open-structure design c
Page 245 and 246: manually removing the bags and plac
Page 247 and 248: Figure 8.12. Increase in worker’s
Page 249 and 250: In other cases, an operation may wa
Page 251 and 252: Cecala AB, O'Brien AD, Pollock DE,
Page 253 and 254: 224 Controls for Secondary SourcesD
Page 255 and 256: where C o = outside respirable dust
Page 257 and 258: minimal improvement in the cab's ai
Page 259 and 260: RECOMMENDATIONS FOR FILTRATION/PRES
Page 261 and 262: Effective FiltrationFigure 9.4. Res
Page 263 and 264: average decay times were between 16
Page 265 and 266: Figure 9.6. Filtration unit showing
Page 267 and 268: This table highlights a number of c
Page 269 and 270: NIOSH [2001b]. Technology news 486:
Page 271 and 272: DUST CONTROL HANDBOOK FOR INDUSTRIA
Page 273 and 274: upon the wind velocity (or disturba
Page 275 and 276: Maximum size is the largest particl
Page 277 and 278: Figure 10.4. Use of end-dumping wit
Page 279 and 280: conditions. Performance of each of
Page 281 and 282: A water truck, used to apply water
Page 283 and 284: Surfactants work by reducing the su
Page 285 and 286: which differed for the various site
Page 287: Figure 10.9. Self-tarping dump truc
Page 291 and 292: Figure 10.12. The armoring process
Page 293 and 294: A current method of stockpile forma
Page 295 and 296: Figure 10.15. Demonstration of how
Page 297 and 298: Chekan GJ, Cecala AB, Colinet JF [2
Page 299 and 300: Midwest Research Institute [1981].
Page 302 and 303: DUST CONTROL HANDBOOK FOR INDUSTRIA
Page 304 and 305: GLOSSARYAbrader. An implement used
Page 306 and 307: Carryback. Material that sticks or
Page 308 and 309: End-dumping. A process of spreading
Page 310 and 311: Open structure building design. A p
Page 312 and 313: Table bushing. A bushing used to se
Page 314: Delivering on the Nation’s promis
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