Modes Of Occurrence Of Hazardous Elements In The No. 5 Coal From The Chuancaogedan Mine, Junger Coalfield

Jungar Coalfield, located in the eastern margin of the Ordos Basin, is an important part of the basin. Coal seams include the Benxi Formation, Taiyuan Formation and Shanxi Formation, containing the total thickness of coal and rock series 110 ~ 160 m, coal-bearing strata of the floor for the middle Ordovician limestone overlying strata Shihezi, Shiqianfeng group, Liujiagou groups and other non-coal-bearing strata. Chuancaogedan mine, located in the southeastern part of Jungar Coalfield, the main mining coal seams are No.4, No.5 No.6, No.9 coal.In order to ascertain the geochemistry of trace elements in the No.5 coal, the optical microscope, SEM and the X-ray Diffraction(XRD), XRF, ICP-MS are used. The occurrence of trace elements were analyzed based on statistics. The results show that :(1) The No.5 coal is briquettes and semi-bright penumbra coal, followed by the bright coal, dull coal rare; contents higher semi-vitrinite. Coal quality characteristics is high ash content, volatile matter, low moisture, special low-sulfur.(2) Minerals in the No.5 coal content kaolinite, magnetite, quartz, calcite, pyrite, gypsum et al, the average content of kaolinite is 97.92%; magnetite, followed by the remaining minerals, only can be detected in individual samples.(3) Major elements in coal: Si O2 and Al2O3 content(average of 51.70%, 42.42%) is much higher than others; following by Fe2O3 and Ti O2(average content of 1.99%, 1.67%); the content of Ca O, K2 O, Mg O, Na2 O, P2O5 is much lower.(4) The content of Hg, Be, F, U is very rich in the No.5 coal; the content of As is low. The content of Li, Ni, Se, Zr, Nb, Cd is high while Cr, Sr is low.(5) Analysis by the relationship of harmful elements in coal and coal material composition, the R cluster symbiotic and combination of correlation, Be, As, U are organic affinity elements; F is strong inorganic affinity elements; Hg is significant positive correlation with sulfur content.(6) Depositional environment of coal formation, the water conditions were qualitative analysis by geochemical indicators, includiing w(Sr) / w(Ba), w(V) / w(Ni), w(V) / w(V + Ni), w(Sr) / w(Cu), ΣREE. The results show that, peat bog in the research area is restore strong, high paleosalinity during the late Paleozoic, resulting Li, Be, F, Ni, Se, U,are relatively rich and As, Sr, Sb, Cs are poor in the No.5 coal.