Geochemistry Characteristics of Rare Earth Elements in Xishanyao Formation Coal from North Yining Mining Area
Rare earth elements(REEs)in coal play significant roles in geological and environmental indications,and can also serve as a substitute for rare earth resources.Coal samples from four main coal seams of Xishanjiang Formation were collected in the north of Yining mine for coal quality and REEs geochemistry.The results indicate that Xishanyao Formation is characterized by low ash,low sulfur,high volatile matter,and high heat value.The ash component is mainly composed of Si,Al,Ca,and Mg oxides.The REEs content in coal ranges from 4.48µg/g to 36.52µg/g,which is lower than the top of the coal seam(36.68µg/g to 191.35µg/g).Coal seams 7#and 6-2#have low REEs content with a flat type distribution showing a negative Ce anomaly.On the other hand,coal seams 6-1#and 5#exhibit high REEs content with a left-leaning type distribution showing a slight negative Ce anomaly and δEu slightly less than 1.The presence of REEs in coal is related to intermediate-acidic igneous rocks and exists in the form of adsorption by clay minerals.It is concluded that during sedimentation period of Xishanyao Formation was dry and hot with an oxidizing environment,and from 7#to 5#depositional period,the water depth decreased and the influence of terrigenous debris on coal seam increased.
rare earth elementsgeochemistrysedimentary environmentnorth Yining mining area
万方数据
维普
