Study On The Occurrence Of Heavy Rare Earth Elements In Hengjian Uranium Deposit,Xiangshan Uranium Ore Field,Jiangxi Province

The Hengjian uranium deposit is a typical granite porphyry-related uranium deposit in the north of the Xiangshan uranium ore field.The ore is rich in heavy rare earth elements.Studying the geochemical characteristics and occurrence status of rare earth elements in the deposit has important guiding significance for the genesis of the deposit and the comprehensive utilization of rare earth elements.In this paper,the geochemical characteristics of the rare earth elements in the Hengjian uranium deposit are analyzed by means of field geological surveys,sample collection,combined with thin-film identification,scanning electron microscopy analysis,electronic probe analysis,and major and trace element geochemical analysis.And the existence state was studied,and the following conclusions were obtained:(1)The geochemical analysis of the ore and surrounding rock elements of the Hengjian uranium deposit shows that the heavy rare earth elements in the uranium ore are significantly enriched.According to the Pearson correlation test,HREE and U are significantly positively correlated,while LREE and U are not significantly correlated.The total amount of rare earth elements in the ore sample?REE+Y is between 234.56�10^-6?2170.57�10^-6,the rare earth distribution curve is inclined to the left or relatively flat,and the rare earth distribution curve of uranium-rich ore shows heavy rare earth enrichment."Left-tilt"type characteristics,the rare earth distribution curve of the surrounding rock presents"right-tilt"type characteristic of light rare earth enrichment,and the heavy rare earth content in uranium-rich ore is 13.7 times that of the surrounding rock.(2)The Hengjian uranium deposit has obvious surrounding rock alteration zones.From the mineralization center to both sides,it is divided into the mineralization center hydromicatic alteration zone,hematite alteration zone near the mine,and near-mineral chlorite alteration.Zone,far-ore sodium feldspar alteration zone and granite porphyry zone.During hydrothermal alteration,P₂O₅appears to be brought in,Fe O and Mn O appear to migrate out.Rare earth elements are generally migrated out of the near-mine chlorite alteration zone,and other alteration zones are brought in,and the closer to the mineralization center,the richer The higher the degree of concentration,the stronger the incorporation of rare earth elements in the hydromicatic alteration zone of the mineralization center.According to the Pearson correlation test,both LREE and HREE were significantly positively correlated with P₂O₅in the samples.(3)The results of the research on the occurrence status of rare earths in the Hengjian uranium deposit show that the rare earth elements mainly exist in homogeneous isomorphism,and a small amount exist in independent rare earth minerals.The minerals that are similar to the rare earth elements are uranium minerals(mainly uranium,followed by pitch uranium ore,titanium uranium ore),vermiculite,apatite and other minerals.Their LREE/HREE are all less than 1,which is expressed as Enriched with heavy rare earths.Independent rare earth minerals are mainly xenotime,monazite and fluorocarbon perovskite.Their heavy rare earth content is greater than that of similar minerals in the Zoujiashan uranium deposit.