THERMOGRAPHIC INVESTIGATIONS OF THE MINERAL FRACTION OF COALS OF THE KANSK-ACHINSK BASIN.

The results are given of thermographic investigations of fractions of different densities isolated from the coals of the Nazarovo, Irsha-borodino, and Berezovka deposits of the Kansk-Achinsk brown-coal basin (USSR). The characteristics of the mineral fraction of the coals investigated and its behavior on heating have been determined. It has been demonstrated that the decomposition of the pyrites present in the coals of the Nazarovo, Irsha-Borodino, and Berezovka deposits takes place in stages with the formation of intermediate products of the type of FeS//2//-//x which, in the presence of atmospheric air, oxidize to Fe//2O//3. The greatest amount of FeS//2 is present in the heavy fractions of the Irsha-Borodino coal and the smallest amount in the Berezovka coal. This explains the appearance of iron monosulfide FeS in the products of the heat fractions of the Irsha-Borodino coal, which is not detected in the products of the heated fractions of the Nazarovo and Berezovka coals. The maximum amount of iron carbonates is present in the Nazarovo coal and the smallest amount in the Berezovka coal.