Mineraiogical And Geochemical Characteristics Of Coal Gangue In Xishan Coalfied,Taiyuan

Coal gangue is a non-metallic mineral resource which is made up of rocks and minerals,and is the solid emissions of coal mining and washing process,and has the comprehensive utilization of attributes.Because of accompanying with coal seam in the process of coal formation,coal gangue have a low rate of carbon content,it has several features,such as low volatile,high ash content,low heating value,hard burnable and so on.Thus its way of utilization is various.At present,except a small amount of coal gangue used in brick or cement,the main part of it is stacked in the open air.Although the little content of trace elements in coal gangue,after weathering and leaching rainwater,because of the large coal mines,there are migrated,transformed and enriched in the ecological system,becoming the important branch of geochemical cycle.And it is also one of the main pollution sources in the coal mining area,damaging to the local ecological environment and having a certain threat to the health of the residents.Strengthening the study of the coal gangue not only can reduce the impact on the environment,but also can solve the problem of storage of gangue.This article selects the Malan and Tunlan coal gangue of Gujiao mining area and Duerping mining area in Xishan coalfield as the object of study.Making use of optical microscope,X-ray diffraction(XRD),scanning electron microscope(SEM)and inductively coupled plasma mass spectrometry(ICP-MS),respectively analysis identification of characteristics to the chariot of Malan and Tunlan coal mine No.2 and No.8 coal gangue rocks of Gujiao mining area and Duerping mining area of Xishan coalfield in Taiyuan,mineral composition,and constants,trace element,and systematically from the aspects of origin,so as to provide theoretical basis for the comprehensive utilization of Xishan coal gangue.The main research contents and conclusions are as follows:(1)Mineralogy and petrology study of coal gangue:By means of optical microscope,scanning electron microscope(SEM),X-ray diffraction(XRD)of Xishan coalfield chariot of Malan and Tunlan No.2 and No.8 coal seam and Duerping coal mine of 16 samples of coal gangue in detail the microscopic identification,it is concluded that No.2 and No.8 coal gangue are composed of kaolinite,quartz,feldspar,mica,pyrite and anatase,etc,which is contained in Malan No.8 coal gangue calcite,content of 58%,No.2 coal waste rock contains a certain amount of illite.Duerping Coal Gangue to clay minerals and quartz,containing a certain amount of dickite and the spontaneous combustion gangue is mainly dominated by ?-quartz.(2)The study about geochemical characteristics of coal gangue:Constant elements contained in the coal gangue are Si,Al,Fe,Ca,Mg,K,Na,P,Ti,Mn,etc.And existing in the form of oxide,among them the content of Si02 and Al2O3 accounted for about 40%to 80%total oxide and Si02 mainly exists in the form of quartz and silicate minerals.No.2 coal gangue of K20,Al2O3 and MgO style and MnO exists in the form of silicate minerals,Ti02 exists in the form of anatase,Fe203-T exist in the form of pyrite,Na20 and CaO take the form of phosphate.Na20 in NO.8 coal gangue,K20,MnO,CaO and MgO style exist in the form of carbonate and phosphate,Al2O3 mainly exists in the form of silicate minerals,Ti02 is mainly exist in the form of anatase and clay mineral,Fe2O3-T mainly exists in the form of pyrite.Trace elements which are composed of it are Li?Be?Sc?V?Cr?Co?Ni?Cu?Zn?Ga?Ge?Rb?Sr?Y?Zr?Nb?Mo?Cs?Ba?Hf?Ta?W,Tl?Pb?Th?U.Most of the trace elements in coal gangue No.8 show the affinity of carbonate and phosphate.The No.2 coal gangues show the affinity of clay minerals and sulfide.The enrichment of W is controlled by the parent rock,while the enrichment of Mo?Pb and U are mainly influenced by seawater,and the enrichment of Zr,Nb,Hf is caused by rock intrusion of a fox suppress a of alkaline complex rock.The formation of No.8 gangues are mainly affected by sea water while the No.2 is influenced by continental environment.(3)Researching on geochemical characteristics of trace elements enriched in coal gangue:Li,V,Zn,Mo,Tl,Pb,U and W gather in the No.8 coal gangue whose forming environment affected by water.While element of Li?Be?Ga?Y?Zr?Nb?Mo?Hf.W?Tl.Pb?Th and U enriched in the No.2 coal gangue whose forming environment affected by continental environmental.The enrichment element of Li,Ga,Zr,Mo,Pb,Th,Hf,W and U are controlled by the parent rock,lithophytes elements Li?Be?Y?Nb?Zr?Mo?Tl?Hf?U?Th and W are affected by alkaline substance,the concentration of V?Mo?U and Pb is accelerated by sea water.