TRANSFORMATION OF MERCURY AND ITS COMPOUNDS UPON COAL PROCESSING

摘要

The information on the mercury content in various coals of several countries is analyzed. Based on the data on the correlations between the mercury content, the total and sulfide sulfur and also the distribution of mercury both in fractions of the coal substance of various density and in coal beneficiation products it has been shown that pyrite (marcasite) is the principal concentrator of mercury in coals. However, in many cases the mercury bearer are concentrates rather than the beneficiation wastes. Equations are proposed for calculations of the extent of extraction of mercury in the industrial beneficiation of coals. It is shown that upon combustion (gasification or carbonization) mercury passes into the gaseous phase in the form of Hg~O and also as HG(Ⅱ) compounds and, probably, Hg(Ⅰ) compounds, the ratio of which in the gas phase determines, in many respects, the possible methods of mercury recovery.