Geochemical Characteristics And Inorganic-organic Interaction Of Trace Element And Rare Rarth Elementin Yimin Coal And Its Humic Acid

Using XRF,ICP-MS,the content of major element,trace element and rare earth element in humic acid series extracted from Yinmin raw coal and demineralized coal was analyzed.Based on industrial analysis and element analysis on chemical composition in humic acid series extracted from Yinmin raw coal and demineralized coal,the content of ash and C,H,0 elements in raw coal and demineralized coal was gotten.By the analysis on the correlation of macroelement,ash,trace element and rare earth element,the inorganic occurrence characteristics of trace element and rare earth element were gotten.Using FT-IR,for humic acid series extracted from Yinmin raw coal and demineralized coal,the organic structure characteristics of chemical composition were analyzed.Combined with the content of trace element and rare earth element in different coal composition,and the correlation analysis of rare earth element,trace element and organic structure in coal,interaction and occurrence of trace element,rare earth element and different composition in coal were studied in detail.Main conclusions are represented below.(1)For raw coal,except Sb,the other trace elements have less content than clarke value,and trace element doesn' t gathered in Yimin lignite.According to the correlation analysis between major element and trace element,most of trace elements occur in silicate,quartz,sodium aluminosilicate and minerals containing Ti.In contrast,trace element has less content in these minerals mainly containing Fe?Mg?Na?Ca?K?Mn,such as pyrite,gypsum,carbonate,sulfate,phosphate.(2)The occurrence of trace element in demineralized coal was analyzed,using acid removal rate.Except Th,Ta,the other inorganic affinity elements occur stably in the minerals of coal.Except Li?Ba?Zn,the other organic affinity elements occur mainly in demineralized coal.Because they combine with oxygen-containing functional group(-COOH?-OH)in lignite,they can be removed when these ionic bonds are broken during acid treating.(3)Trace elements,V?Ni?Cu?Zr?Mo?Cd?In?Sb?Ta?W?Th,can form stable organic compounds with humic acid,and V?Ni?Sb?Ta can also form stable organic compounds with the macromolecule in coal.(4)The correlation analysis between rare earth element and ash of raw coal and demineralized coal,and major element in raw coal,tells that rare earth element in Yimin lignite mainly occurs clay mineral and titanium—bearing mineral.Minerals,such as pyrite,carbonate,sulfate,have less rare earth element,which has attenuation function.Geochemistry parameters analysis on rare earth element in coal and humic acid shows that,for organic material,heavy rare earth element mainly occurs in humic acid,and light rare earth element mainly occurs in organic structure of coal.(5)The combination of the trace element,the rare earth element and organic structure of coal can be classified as following.? ones with aromatic structures trisubstituted substituted by hydrogen,?ones with ether,carboxylic acid,phenolic hydroxyl group,?ones with aromatic hydrocarbons C=C,?ones with aromatic structures highly substituted by aliphatic side chains,? ones with hydroxyl hydrogen bond.(6)When the combination of rare earth element and aromatic structures substituted by hydrogen is influenced by the shrinking effect of lanthanum,it will increase or decrease with the increasing of atom sequence number,And some rear earth elements will show abnormal feature.When the combination of rare earth element and organic structure not only is influenced by the shrinking effect of lanthanum,but also is influence by valence state of element,the combination rule will get complex,including V type,inverted V type,and saw tooth type.