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Engineering Controls Database

Best Practices for Dust Control in Coal Mining – Continuous Mining Operations – Feeder-Breakers and Shuttle Cars

Respirable dust exposure has long been known to be a serious health threat to workers in many industries. In coal mining, overexposure to respirable coal mine dust can lead to coal workers’ pneumoconiosis (CWP). CWP is a lung disease that can be disabling and fatal in its most severe form. In addition, miners can be exposed to high levels of respirable silica dust, which can cause silicosis, another disabling and/or fatal lung disease. Exposure to coal mine dust may also increases a miner’s risk of developing chronic bronchitis, chronic obstructive pulmonary disease, and pathologic emphysema.

Once contracted, there is no cure for CWP or silicosis. The goal, therefore, is to limit worker exposure to respirable dust to prevent development of these diseases.
CWP contributed to the deaths of 10,406 U.S. miners during 1995–2004 [NIOSH 2008]. Pneumoconiosis continues to be a very serious health threat to underground coal mine workers.

The greatest source of respirable dust at continuous mining operations is the continuous mining machine. Dust generated by the continuous miner has the potential to expose the miner operator and anyone working downwind of the active mining. Dust measurements show that feeder-breaker operations can also contribute a significant amount of respirable dust exposure to shuttle car operators r, which emphasizes the need for dust controls at this location [Potts and Jankowski 1992]. Outby areas can be placed on a more stringent dust standard due to the presence of respirable silica dust. A study by Organiscak et al. [1990] showed elevated respirable silica dust concentrations at the feeder-breaker and on the shuttle car
Following are some basic controls for these areas:

• MSHA recommends hollow- or full-cone sprays at the feeder-breaker transfer point to wet and knock down coal and silica dust [Ondrey et al. 1994].

• When shuttle cars unload, dust levels can be decreased by using automated sprays at the mouth of the feeder-breaker that activate during dumping to wet coal before it enters the crusher.

• Throat sprays on the continuous miner will wet coal when entering the conveyor and lessen dust when transferred to and from shuttle cars. Redistributing a small portion of the water available on the continuous mining machine to the chain conveyor may be necessary to ensure that the loaded coal is wet enough to minimize dust reentrainment at the section loading point [Ondrey et al. 1994].

• Shuttle cars should not be in a waiting position beneath check curtains.

• Shuttle car operators should not be located in the direct discharge of the dust collector (scrubber) on the continuous miner.

• When blowing ventilation is used, configure shuttle car runs to minimize the amount of time spent in return air.
NIOSH [2010]. Information circular 9517. Best practices for dust control in coal mining. Morgantown, WV: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, DHHS (NIOSH) Publication No. 2010-110.

MSHA [2009]. Standardized Information System: Respirable coal mine quartz dust data. Arlington, VA: U.S. Department of Labor, Mine Safety and Health Administration.

NIOSH [2008]. Work-related lung disease surveillance report, 2007. Morgantown, WV: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, DHHS (NIOSH) Publication No. 2008143a.

Ondrey RS, Haney RA, Tomb TF [1994]. Summary of minimum dust control parameters. In: Proceedings of the Fourth Symposium on Respirable Dust in the Mineral Industries (Pittsburgh, PA, November 8–10, 1994).

Potts JD, Jankowski RA [1992]. Dust considerations when using belt entry air to ventilate work areas. Pittsburgh, PA: U.S. Department of the Interior, Bureau of Mines, RI 9426.
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