Dust Control Handbook for Industrial Minerals Mining and Processing

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soil surface becomes compact and mechanically stable, thus becoming more resistant towind erosion. The soil must have an appropriate amount of fine material in order to bindthe larger materials to form the crust. However, the degree of cementation is hard todetect, making it difficult to measure the amount of cementation required for windresistance, i.e., the number of wet/dry cycles required to prevent erosion (Chepil 1958).The amount of moisture in the soil also affects the erodibility of soil. Basically, as themoisture is increased, the erodibility of the soil decreases [Chepil 1956]. This is importantfor dust control of open areas. However, it has been shown that even soils with highmoisture contents can be susceptible to wind erosion. With loose soil, with a depth of 5cm, the erodibility of a moist soil can be similar to that of a dry soil if the wind speedapplied to the moist soil is 15–20 mph more than that applied to the dry soil [Cowherd andGrelinger 1996]. Therefore, while wetting is a good dust control measure, the area muststill be monitored to maintain the proper amount of moisture to prevent erosion.CoatingsCoatings as a dust control method generally include water or a myriad of chemicalstabilizers in commercial production. The best coatings that prevent wind erosion form acrust on the surface of the material or soil. Additionally, the best coatings are nontoxic toplants, water permeable, and allow the material to be handled easily. The drawbacks tocoatings are that they are expensive, and once the crust created by the coating ispenetrated, erosion readily resumes [Diouf et al. 1990; Armbrust and Dickerson 1971;Lyles et al. 1969].Mixing bentonite clay with soil is a dust control for open areas. Water is applied,allowing the soil-bentonite mixture to form a crust on only the top of the mixture.Beneath the crust the material is unconsolidated, as water is not able to penetrate the crust.Bentonite concentrations that are too high leave easily erodible sand particles (
A current method of stockpile formation for long-term storage is to build the stockpile andcompact it using bulldozers (Figure 10.13). The compaction helps to prevent winderosion. Additionally, coatings or binders can be used to aid in dust control. Waxmixtures (hot-melt formulations) and polyethylene and polypropylene latex emulsionshave been found to be useful in past applications for coal stockpiles and could be adaptedto be applied to other mineral stockpiles. The latex emulsion coatings are thinner andmore water-permeable than the hot-melt formulations. The latex emulsion coatings alsorequire a surface preparation of spreading fines over the entire stockpile prior toapplication. However, all coatings, both latex emulsion and hot-melt formulations, aresignificantly better at dust control over stockpiles with or without compaction (with thecompacted stockpile better at dust control than stockpile without compaction).One disadvantage to latex emulsion coatings for dust control is that this type of coatingmust be applied at temperatures >50°F, whereas hot-melt formulations can be applied inany weather condition [Kromrey et al. 1978]. Acrylic resins or polymers can also be used,but require a three-day curing period to form a crust on the surface of the stockpile. Thesecoatings are very wind resistant to erosion, except if the stockpile surface is disturbedthrough settling or cracking, in which case wind erosion can resume as occurs with anuntreated stockpile [Smitham and Nicol 1991].Figure 10.13. Dozer being used to compact stockpile for long-term storage.Micro-foam is another method for controlling dust from fugitive dust sources, particularlyload-out stockpiles. Typical foams used in firefighting (large 5-mm bubbles) are noteffective at dust control, unlike micro-foam (small
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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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Spills of product material are a co
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epetitive dust leaks should not sim
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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 and 288: Figure 10.9. Self-tarping dump truc
Page 289 and 290: percent [Fryrear and Skidmore 1985]
Page 291: Figure 10.12. The armoring process
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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