Geochemical Characteristics Of Rare Earth Elements In Coal In Weibei Coalfield And Qinshui Basin

The unique geochemical characteristics of rare earth elements can not only be used to judge the source of coal-forming materials and the geological origin of coal,but also the rare earth element-rich integrated ore can greatly alleviate the scarcity pressure of rare earth elements.Therefore,the research on rare earth elements has very important theories and Practical meaning.In this paper,the characteristics of coal quality,content distribution,distribution mode and occurrence state of rare earth elements in coal from Weibei coalfield and Qinshui Basin were studied by coal industry analysis,X-ray diffraction,X-ray fluorescence spectrum,optical microscope and inductively coupled plasma mass spectrometry.The results are as follows:The Carboniferous-Permian coal in the Weibei Coalfield is a low-water,low-ash,low-volatile,medium-high-sulfur coal,a coking coal or lean coal with a moderate degree of metamorphism.The Taiyuan Group No.11 coal is a high-ash,high-sulfur coal,and the rest are low-ash coals.,Low-sulfur coal.The Carboniferous-Permian coals in the Qinshui Basin are mainly low-water,low-ash,and low-volatile medium-sulfur coals,high metamorphic anthracite coals,Taiyuan coals are medium-high sulfur coals,and sulfur content is mainly organic sulfur and pyrite sulfur,While the Shanxi coal is ultra-low-sulfur coal,and the sulfur content is mainly organic sulfur.The content of rare earth elements in the coal of Weibei Coalfield(99.17?g/g)is slightly higher than the content of rare earth elements in the coal of Qinshui Basin(95.60?g/g).The distribution characteristics of rare earth element content in the two places are consistent: The rare earth elements in the coal of Shanxi group are slightly less than those of Taiyuan group.The content of light rare earth,medium rare earth and heavy rare earth elements shows the largest content of light rare earth elements,followed by medium rare earth elements and finally heavy rare earth elements;The enrichment coefficients relative to the average value of rare earth elements in Chinese coal are 0.73 and 0.71,respectively.Although they belong to the normal enrichment range,many samples show a loss of rare earth elements.The coals in the Weibei Coalfield and the Qinshui Basin are both rich in light rare earth elements.The average values of ?Eu are 0.91 and 0.97,and the average values of ?Ce are 0.91 and0.95,respectively.Both places show weak Eu and Ce negative anomalies.It shows that the rare earth elements in coal mainly come from terrigenous debris,the seawater intrusion did not cause the loss of Ce,and it also shows that the sedimentary environment is a weak oxidation-weak reduction environment.There is an obvious positive correlation between rare earth elements and ash in Weibei coal field.The inorganic affinity of light rare earths,medium rare earths and heavy rare earth elements are in order of heavy rare earths,light rare earths and medium rare earths.At the same time,through correlation with major elements and cluster analysis,it is inferred that the rare earth elements in Weibei coal field coal are mainly found in clay minerals,followed by phosphorus-containing minerals such as apatite and carbonate minerals.The inorganic affinity of rare earth elements in coal in the Qinshui Basin is relatively weak.Through correlation and cluster analysis,it is inferred that rare earth elements have a certain correlation with clay minerals,but a considerable part of them are contained in organic matter.