Abstract: Mitigating Environmental Impacts of Coal Use

Robert B. Finkelman

It is widely recognized that coal production and use can create severe environmental problems. Knowledge of coal quality parameters can help in the efforts to mitigate some of these problems. For example, coal combustion may release potentially hazardous air toxics (antimony, arsenic, beryllium, cadmium, chromium, cobalt, lead, manganese, mercury, nickel, selenium, and uranium). Models to predict the vertical and lateral distribution of these elements in coal may help identify deposits that have relatively low concentrations of these elements or develop mine plans to exploit coal in ways that minimize concentrations of these elements. Alternatively, information on the modes of occurrence and textural relations of these elements may provide data to model the behavior of these elements uring coal cleaning and combustion. Thereby helping to minimize environmental impacts.

With knowledge of the modes of occurrence, elements may be more efficiently removed by coal beneficiation. For example, in some coal beds, galena (PbS) may occur as grains attached to large pyrite particles or as relatively large cleat and fracture-filling crystals. In these cases, most of the galena, and the associated Pb, will be removed during coal cleaning. However, in other coal beds, fine-grained galena may be dispersed throughout the organic matrix. In these cases the galena, and the associated Pb, cannot be removed by conventional coal-cleaning methods.

The oxidation and leaching behavior of coal and the minerals in coal varies with the environmental conditions. Therefore, coal quality information also may help in the mitigation of environmental problems resulting from leaching of organic and inorganic matter from exposed coal beds, coal storage piles, and especially, coal waste deposits.

AAPG Search and Discovery Article #90986©1994 AAPG Annual Convention, Denver, Colorado, June 12-15, 1994