煤中有害微量元素的洗选迁移特性

Migration characteristics of hazardous trace elements in coal in the process of flotation

应用浮沉试验和分步释放浮选试验对贵州省水城煤业集团大河边矿原煤进行了洗选分离,采用电感耦合等离子体质谱(ICP-MS)测定了原煤和11个洗选产品中As,Se,Cd,Pb,Be,Cr,Co,Mo,Cu,Zn,Ni,V,Sb,Mn,Th,U等潜在有害微量元素的含量,应用等离子体低温灰化分离出原煤和洗选产品中的无机矿物质。结果表明,原煤中微量元素的总体含量水平中等;在浮沉试验中密度越高的洗选产品中微量元素的含量越高;在分步释放浮选试验中,精煤中微量元素的含量最低,尾煤中微量元素的含量最高,在中间产品中呈过渡关系;绝大多数微量元素与矿物质总量之间都存在极高的相关性,表明微量元素在煤中主要以无机态赋存,其迁移特性主要受控于煤中的矿物质。

Float-sink analysis and coal flotation test by progressive release were conducted on a raw coal collected from Dahebian coal mine,Guizhou Province.The concentration of As,Se,Cd,Pb,Be,Cr,Co,Mo,Cu,Zn,Ni,V,Sb,Mn,Th,U,and mineral matter in raw coal and float products were determined by inductively coupled plasma mass spectrometry（ICP-MS） and low temperature asher（LTA）.The results indicate that the concentration of trace elements in Dahebian coal is medium;the concentration of trace elements tend to increase with increasing specific gravity in float-sink analysis;the concentration of trace elements is highest in the tailings,lowest in clean coal,and medium in other washing products in flotation test.Linear regression of trace element and mineral matter content shows that the majority of the trace elements are associated with the mineral matter in coal,so they have strong associations with the mineral matter,and their migration characteristics is also controlled by the minerals in coal.