Environmental impacts at coal waste disposal sites-efficiency of desulphurization technologies

During beneficiation of coal at the coal mining area of Tula, Russia, huge volumes of coal wastes with
considerable residual pyrite content are produced. These wastes that are usually disposed of without
specific care in the environment are active sources of coal mine drainage generation which severely
contaminates soils, surface- and groundwater and endangers the ecosystems of the area.
In the present paper a complete environmental characterization research is carried out in order to
determine the characteristics of the wastes, establish their acid generation potential, the leachability
and bio-availability of several hazardous constituents and predict the environmental impacts at the disposal
sites. Based on this data as well as on process parameters and disposal practices, an evaluation of
desulphurization technologies is carried out.
Experimental studies reveal that these wastes are considered as permanent sources of coal mine
drainage generation and therefore cause extensive contamination at the disposal sites. In addition, due
to several technological constraints of the desulphurization technologies and the characteristics of the
wastes, the potential of in situ desulphurization is considered low. Desulphurization technologies present
a higher potential only if applied in the framework of an integrated waste management scheme.