Handbook for Methane Control in Mining - AMMSA

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After the shaft was filled, mine gases continued to leak to the surface. Explosive concentrationsof methane were measured at the surface, so air-powered tools were used to dismantle the fans.In addition, elevated carbon dioxide levels and oxygen deficiencies persisted in the fan housingand the structures surrounding the shaft collar. Nevertheless, the project was completed withoutfurther incident.Shaft filling in Germany. Hinderfeld [1995] reported on the methane safety precautions takenduring shaft filling in Germany, where more than 100 shafts had been filled in the previous10 years. When shafts are not under the influence of a fan, the flow of methane is controlled bythe barometric pressure. High flows of methane have been observed when the barometric pressurefalls and the gas-laden mine air expands and fills the shaft from below. In this situation, it isimportant to monitor the barometric pressure.The preferred approach to shaft filling at each mine is to ensure that the shaft being filled isdowncast and ventilated with a fan in another shaft. The last two shafts at the mine are thenclosed off simultaneously and filled as quickly as possible.During filling, the methane concentration is continuously measured at a point 50 m (164 ft)below the surface. If a threshold value—established for that particular shaft—is reached, thenfilling work stops and the shaft is probed to the bottom.When high methane concentrations are recorded, and if these are not diluted during a subsequentbarometric pressure increase, the shaft atmosphere is inerted by adding enough carbon dioxide ornitrogen to reduce the oxygen content below 10%. 10133REFERENCESCFR. Code of federal regulations. Washington DC: U.S. Government Printing Office, Office ofthe Federal Register.Cook AP [1998]. The occurrence, emission, and ignition of combustible strata gases inWitwatersrand gold mines and Bushveld platinum mines, and means of ameliorating relatedignition and explosion hazards. Final project report, project GAP 504. Braamfontein, Republicof South Africa, Safety in Mines Research Advisory Committee (SIMRAC) (www.simrac.co.za).Denk JM, Francart WJ, Baran JN [1987]. Monitoring mine gases during shaft filling operations.In: Proceedings of the Third Mine Ventilation Symposium (University Park, PA, October 12–14,1987).10 When a shaft is under the influence of barometric pressure, adding carbon dioxide or nitrogen can be a betterapproach than diluting methane with compressed air. When compressed air is used, a spike in the methane flow dueto a falling barometer may move the shaft atmosphere into the explosive range. When the shaft is inerted, a spike inthe methane flow may drive the shaft atmosphere at the bottom further into the inert range.
134Hinderfeld G [1995]. Ventilation-technical and gas management measures within closing downof coal mines. In: Proceedings of the 26th International Conference of Safety in Mines ResearchInstitutes (Katowice, Poland, September 4–8, 1995). Vol. 2. Katowice, Poland: Central MiningInstitute, pp. 201–217.Maksimovic SD [1981]. Control of methane by ventilation of shafts during raise drilling. Pittsburgh,PA: U.S. Department of the Interior, Bureau of Mines, IC 8847. NTIS No. PB81234502.Mills B [2003]. Fatal shaft explosion report investigation, McElroy Coal Co., McElroy mine,Permit No. U–83–33, Central Cambria Drilling Co., contractor No. C–618, January 22, 2003.Fairmont, WV: West Virginia Office of Miner’s Health, Safety and Training.Oakes JK, Tortorea JS, Stoltz RT, Stephan CR, Brown VF, Penigar RA, et al. [2003]. Report ofinvestigation, fatal shaft sinking explosion, January 22, 2003. McElroy mine, McElroy CoalCompany (subsidiary of CONSOL Energy Incorporated), Cameron, Marshall County, WestVirginia, ID No. 46–01437. Arlington, VA: U.S. Department of Labor, Mine Safety and HealthAdministration.
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TMIC 9486Information Circular/2006H
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ORDERING INFORMATIONCopies of Natio
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ILLUSTRATIONS—ContinuedPage4-6. U
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HANDBOOK FOR METHANE CONTROL IN MIN
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4Below 5%, called the lower explosi
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6reduced pressure, except at very l
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8Static electricity. Protection aga
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10Figure 1-4.—Estimated methane c
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12LAYERING OF METHANE AT THE MINE R
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14good eyesight. 24methane level.Ot
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16a material balance indicated that
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18As an example, assume that themet
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20Figure 1-10.—Relative frequency
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22Davies AW, Isaac AK, Cook PM [200
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24Margerson SNA, Robinson H, Wilkin
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CHAPTER 2.—SAMPLING FOR METHANE I
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29USING PORTABLE METHANE DETECTORST
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Out-of-range gas concentrations in
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Figure 2-3.—Recorder chart from a
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35Industrial Scientific Corp. [2004
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38peaks, not the overallmethane lev
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40hung on J-hook assemblies, which
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42Methane dilution effectiveness.Th
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44found that effective scrubber ope
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46When the scrubber exhaust is not
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48Methane monitors are usually moun
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50to use radial bits instead of con
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52Mott ML, Chuhta EJ [1991]. Face v
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54Service, Centers for Disease Cont
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56Methane accumulationsaround thesh
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58corner and by 43% at supportNo. 4
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60When using water sprays to reduce
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62Cecala AB, Zimmer JA, Thimons ED
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64DESIGNING BLEEDER SYSTEMSAs part
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66Caved area characteristics. The c
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68then move this gas into the activ
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70perform tests to determine whethe
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72A major purpose of the bleeder sy
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74• Inlets to the pillared area n
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76REFERENCESCFR. Code of federal re
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78Methane is released into each min
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80Figure 6-1.—Gas content of coal
Page 87 and 88: 82Figure 6-3.—Simplified illustra
Page 89 and 90: 842. In-mine inclined or vertical b
Page 91 and 92: 861. Packed cavity method and its v
Page 93 and 94: 88Table 6-3.—Methane capture rati
Page 95 and 96: 90Early experiences with this metho
Page 97 and 98: 9211. At the surface installation (
Page 99 and 100: 94• Estimated cost for moderately
Page 101 and 102: 96Thakur PC [1981]. Methane control
Page 103 and 104: 98Anomalous, unanticipated methane
Page 105 and 106: 100Vertical methane drainage boreho
Page 107 and 108: 102Figure 7-2 shows a mine entry ap
Page 109 and 110: 104obvious solution to this problem
Page 111 and 112: 106Figure 7-8.—Hypothetical gas c
Page 113 and 114: 108Lama and Bodziony [1998] compile
Page 115 and 116: 110In-mine methane drainage systems
Page 117 and 118: 112Iannacchione AT, Ulery JP, Hyman
Page 119 and 120: 114More sophisticated reservoir eng
Page 121 and 122: 116coal lithotype on gas content is
Page 123 and 124: 118FORECASTING REMAINING GAS-IN-PLA
Page 125 and 126: 120⎛ y⎞⎜⎛⎞ ⎛ ⎞= ⎜
Page 127 and 128: 122emissions. The geometry and size
Page 129 and 130: 124Reservoir models require a subst
Page 131 and 132: 126King GR, Ertekin T [1989a]. A su
Page 133 and 134: 128an area of 314 ft 2 would requir
Page 135 and 136: 130In the case of the abovementione
Page 137: 132FILLING SHAFTS AT CLOSED MINESFi
Page 141 and 142: 136To calculate the effectiveinert,
Page 143 and 144: 138exhaust. The remaining diesel ex
Page 145 and 146: 140required only 4 min. As a result
Page 147 and 148: 142Figure 11-1.—Desorption test a
Page 149 and 150: 144enclosed in a tunnel-like struct
Page 151 and 152: 146Kolada RJ [1985]. Investigation
Page 153 and 154: 148air in a 6-ft by 9-ft by 6.5-ft
Page 155 and 156: 150represents flammable mixtures. F
Page 157 and 158: 152• In Eastern Europe, petroleum
Page 159 and 160: 154Category II applies to domal sal
Page 161 and 162: 1562. Monitoring for gas and taking
Page 163 and 164: 158These mines typically have large
Page 165 and 166: 160Dave Graham is the safety and he
Page 167 and 168: 162Figure 13-2.—Examples of metha
Page 169 and 170: 164REFERENCESAndrews JN [1987]. Nob
Page 171 and 172: 166APPENDIX A.—ONTARIO OCCUPATION
Page 174 and 175: 169CHAPTER 14.—PREVENTING METHANE
Page 176 and 177: Ways to confirm the presence of gas
Page 178 and 179: 173The tunnel face is usually venti
Page 180 and 181: 175Figure 14-5.—TBM ventilation s
Page 182 and 183: face. While one of these elements a
Page 184 and 185: 179ELIMINATING IGNITION SOURCESElec
Page 186 and 187: 181INDEXAAbnormally gassy faces....
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183NNatural ventilation, coal silos
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Delivering on the Nation’s Promis
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