Study On Trace Elements Of No.2 Coal Seam In Ningdong Coalfield Central

The study on abundance,distribution,occurrence state of trace elements in the coal,is help to discuss the origin and the formation of coal.It has important significance for the development of new energy in coal and preventing the pollution of the harmful elements to the environment in coal combustion process.Content level,occurrence state,enrichment mechanism,coal petrology and organic matter characteristics of the No.2 coal seam from Ningdong Coalfield Central have been researched,using the knowledge of coal petrology,mineralogy,organic geochemistry,sedimentology,coal geology.Coal facies and sediment source have been inferred by the characteristics of trace elements.The methods used respectively are microscope observation,inductively coupled plasma mass spectrometry(ICP-MS)testing,organic extraction experiment,LTA-XRD and gas chromatography,etc.The results indicate that the enrichment coefficients of Cd,Ga,In,Tl and B are greater than 1 in No.2 coal mine.However,by comparing with the average value of China,the America and world,the content of latent toxic trace elements Cd are higher in the samples,with enrichment coefficient large than 7.0,obviously riched.Vitrinite and inertinite are the dominant microscopic macerals,and less liptinite in No.2 coal seam;Minerals in the majority with carbonate mineral,the second are clay mineral,sulphide,oxide minerals;Soluble organic matter has low in saturated hydrocarbon,high in aromatic hydrocarbons,and lower ratio of saturate features.Through the analysis of maceral group and organic matter in coal,the author concludes that coal-forming plant most are higher plant,but also have lower plants and aquatic organisms.The dominant peat bog type is fen,and the damp forest swamp is complementary transition type.The relationship of trace elements and minerals,and macerals,and organic extraction has been researched.The trace element in microscopic component is less likely to occur,and close to the minerals.Pb?Bi?Li?Cr?In?REE and Ni usually occur in clay minerals;Ga?Ba and Mn may mainly occur in carbonate minerals;Rb?Cs?Co and Cu occur in sulphide minerals.Mn?Pb?Cr may mainly occur in Oxide minerals.Trace elements associated with vitrinite Mn and Tl;Trace elements associated with inertinite Mn,Li,Co,Ni,Ga,Rb,Cd,In,Ba,REE and Be;Trace elements relate to exinite Co,Sr,Tl.