Study On Some Sensitive Trace Elements And Their Environmental Significance In Coal From The Jibei Coalfield

Occurrence of environmental sensitive trace elements in coal have been paied attention to by many researchers in resent years, and the research of this aspect has great significance on controlling release of environmental sensitive trace elements and protecting human health. The distribution, modes of occurrence, and environmental behavior of sensitive trace elements in the Jibei Coalfield were investigated using instrument analysis, chemical experiments in the present study, and the results indicate as follows.(1) Compared to the average values of sensitive trace elements in coals from China, trace elements such as B, Cd, Cr, Mn, Ni, Se, As in the Jibei Coalfield enriched; and the average values of B, Cd, Cr, Mn, Ni, and As are also higher than in coals from North China;(2) The contents of sensitive trace elements vary in different coal mines, different coal seams in the Jibei Coalfield, for example, the average values of As, B, Hg, and Se in the Tangkou coal mine from south Jibei Coalfield are higher than in the other three coal mines, and the average B value in coal seam 16 is obvious higher than in coal seam 3. But in biforked coal seams (upper 3 coal seam and under 3 coal seam), the average values of sensitive trace elements are similar;(3) As, B, Cr, Hg, Mn and Ni have strong affinity with inorganic material in coal, and As, Hg, Mn, and Se have obvious positive correlation with pyrite-sulfur, and sulphide may be the carrier of these trace elements in coals. The average values of B, Cr, and Ni have positive correlations with organic-sulfur in coals, and this indicate that these trace elements have strong affinity with organic sulfur in coal;(4) The sensitive trace elements in soils and water bodies are positive to that in coals, and the accumulation of coal and dirt in the coal mine may be the main factors that results in pollution of environmental sensitive trace elements As and Se in water bodies in coal mines;(5) Leaching experiment indicates migration of sensitive trace elements in coal varies with conditions of times and pH values. The concentrations of As, Hg, and Se release are obviously higher in acidic environments and in intial stage, and with the increase of leaching experiment time, the concentrations of As, Hg, and Se release increase.