The Trace Elements In NO.9 Coal Seam From Gequan Mine,Xingtai Coalfield

China is,and will continue to be one of the largest coal producers and users in the world.In some specific geological conditions,some trace elements can be enriched in coal and even formed ore deposit associated with coal.And the harmful trace elements will be released during coal utilized.So it is very important to study the content,distribution,occurrence and enri'chment of trace elements.This paper discussed many aspects of the No.9 coal of Taiyuan Formation Carboniferous in Gequan Mine which included the lithotype,mineral,coal-forming environment,coal plant;the content,enrichment,distribution of trace elements of the No.9 coal and the contrasted with the average concentrations of trace elements in coals of Carboniferous-Permian of North China,China,USA and the World,the characteristic of harmful elements and REEs,the source and enrichment factors.The samples were examined by using coal analysis,fluorescence microscope(MVP-?),scan electronic microscope(SEM),inductively coupled plasma mass spectrometry(ICP-MS),gas chromatography(GC).It concluded that No.9 coal was formed in the formed in forest and swamp facies sedimentary environment.Lithotypes is semi-bright coal,and the class of No.9 coal is high rank.Most of the minerals are clay in the coal.The correlation analysis shows that most trace elements are concerned with the mineral,and the others are closely related with the organic components.Compared with the coals of Carboniferous-Permian of the North China,the concentrations of most trace elements are higher.The contents of Li?Ga?Sr?Mo?Cd?In?Sb?Pb?Bi?U and Zr are higher than the clark value.The content of harmful elements are normal,which are harmless to the environment.The geochemical characteristics of REEs show that the REEs of No.9 coal were mainly terrigenous.Enrichment factors show that the trace elements of No.9 coal were mainly terrigenous and groundwater leaching played an important role in the enrichment of trace elements.