ABSTRACT
Thus, in the early 1980s, the coal industry was expected to supply additional, primary sources of energy. However, in reality, coal output, coal quality and methods of coal combustion, together with the above-mentioned trends, were affected by the increasingly pressing need to solve environmental problems. In addition to the increasing technical difficulties associated with coal mining, the need for environmentally sound methods of coal utilization (mainly for power generation) became even more urgent [8].
