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Control of Airborne Respirable Dust Hazards: A Training Program for Underground Coal Miners. Penn State. The Penn State Miner Training Program University Park, PA 16802 Raja V. Ramani, Ph.D., P.E, C.M.S.P. Mark C. Radomsky, Ph.D. MPA, C.M.S.P. Joseph P. Flick, M.S., C.M.S.P.
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Control of Airborne Respirable Dust Hazards:A Training Program for Underground Coal Miners Penn State The Penn State Miner Training Program University Park, PA 16802 Raja V. Ramani, Ph.D., P.E, C.M.S.P. Mark C. Radomsky, Ph.D. MPA, C.M.S.P. Joseph P. Flick, M.S., C.M.S.P. March 31, 2003
CENTERS FOR DISEASECONTROL AND PREVENTION NATIONAL INSTITUTE FOR OCUPATIONAL SAFETY AND HEALTH GENERIC MINERAL TECHNOLOGY CENTER ON RESPIRABLE DUST PENNSYLVANIA BUREAU OF DEEP MINE SAFETY
RESPIRABLE DUST TRAINING PROGRAM Section 7 UNDERGROUND MINING METHODS AND SOURCES OF DUST
The working environment in underground coal mining is completely enclosed by the geological medium consisting of the coal seam, and the strata above and below the coal seam. Mining process consists of two kinds of operations: Unit operations Auxiliary operations Mining Process and Environment
Mining Process and Environment • Unit operations are repeated in a cycle to extract coal, and develop the mine and mine the coal seam • Unit Operations – cutting, drilling, blasting, loading, hauling and roof bolting • Unit operations are repeated in the face areas and all unit operations produce dust
Mining Process and Environment • Auxiliary operations provide the support services necessary for the unit operations to function effectively. • Auxiliary Operations – ventilation, ground control, drainage, power, main haulage, communications and lighting. • Auxiliary operations can produce dust. Ventilation is a major dust control auxiliary operation.
Underground Coal Mining Methods There are two major U.S. underground coal mining methods with several sub-classes: • Room and Pillar Methods – common methods • Conventional Mining Method • Continuous Mining Method • Longwall Methods – common methods • Longwall Retreating Method with Shearers • Longwall Retreating Method with Ploughs
Projection of a Hypothetical Mine Showing the First Two Years of Development
Distribution of Broken Material by Respirable, Airborne and Large Particle Size
Mining Sequence in 7-Entry Development for a Conventional Mining Section
Sources of Dust in Mines Conventional Mining Section • Kerf Cutting by the Coal Cutter • Drilling of the Blast Holes in the Face • Blasting of the Coal • Loading of Coal to Shuttle Cars • Drilling for Roof Bolt Holes • Feeder Breaker at the Dump Point • Panel Conveyor • Contamination of Intake Airways
Mining Sequence in 5-Entry Development for a Continuous Mining Section
Sources of Dust in MinesContinuous Mining Section • Coal/Rock Cutting by Continuous Miner [CM] • Coal/Rock Falling to the Ground • Gathering and Loading of the Coal by CM • Loading the Coal on to Shuttle Cars • Drilling for Roof Bolting • Feeder Breaker at the Dump Point • Panel Belt Conveyor • Contamination of Intake Air
Typical Longwall Section Stage loader Roof supports Shearer Conveyor Gob
Sources of Dust in MinesLongwall Mining Section • Coal/Rock Cutting by Longwall Shearer • Advance of the Shield Supports • Breaking of Coal at Stageloader/Crusher • Panel Belt Conveyor • Contamination of Intake Air
Sources of Dusts in Mines • Primary Sources– These are sources in which the dust produced primarily from breaking the coal or rock from the seam or strata. Examples include: continuous miners, longwall shearers, roof bolting machines, and blasting. • Secondary Sources – These are sources in which the dust is produced from secondary breaking arising from loading, transferring and transporting the coal. Examples include loading machines, stageloader/crusher, conveyor, and reentrainment of settled dust.
Sources of Dusts in Mines • The above two sources can be further broken down into major, minor and negligible sources on the basis of their contribution to the overall dust load in the mines. • Major sources include continuous miner, longwall shearer, and roof bolting machines • Minor sources include loaders and roof bolters • Negligible sources include conveyors, and reentrainment
Proceed to Section 8 Longwall Dust Control Methods