Study On Occurrence State And Source Of Uranium In Phosphorus Deposits Of Bahuang,Tongren,Guizhou Province

The radioactive element of Uranium enrich in the phosphorus ore deposit from Bahuang.For a long time,people paid less attention to the research work on the development of phosphate rock type uranium deposit,and the research level is low.Therefore,reserching on the occurrence state and material source of uranium in phosphorus deposits of Bahuang,it is helpful to further study the genetic mechanism of the phosphorite type uranium deposits and summarize the metallogenic regularity.So as to lay a theoretical basis for the comprehensive utilization of resources and realize the optimal allocation.In this paper,the petrology,element geochemistry and ore deposit study of the ore bearing rock series are carried out through rock mineral identification,a-track photography,scanning electron microscopy and energy spectrum analys methods.Studied the geological characteristics and mineral assemblage characteristics of the uranium rich phosphorite systematically,analyzed the occurrence state and material source of uranium.The main achievements are as follows:(1)The thosphorus-uranium deposit is located at the bottom of Niu titang Formation,the direct roof of Ni-Mo-V polymetallic ore,and the underlying strata is siliceous rocks of Laobao Formation in study area.(2)The phosphorus-uranium deposits is mainly composed of apatite and phosphate,uraninite,coffinite,clay minerals,quartz,calcite,pyrite and organic matter etc.,with banded structure,lamellar structure,vein structure and gel structure,recrystallization structure and skeleton crystal structure.The mineral assemblages have two types: apatite-clay minerals-siliceous minerals and colloidal-calcite-clay minerals.(3)In phosphate rock uranium mainly isomorphous exist phosphate minerals,which is attached to the surface of clay minerals,organic matter and pyrite.The uranium in the phosphate rock is also in the form of independent minerals of uraninite and coffinite.(4)The material composition,macro-and micro-structure of the ore bearing strata show that the study area is generally affected by the tectonic metamorphism.Uranium rich phosphorus ore geochemical characteristics of major elements,trace elements contrast values,REE patterns and anomalies,indicating uranium rich phosphate rock for non normal seawater deposition of Bahuang,reflecting the ore bearing provenance mainly come from deep material,which related to basic rocks,mafic and acidic rocks,mainly in hot water deposition,part of the source affected by terrigenous materials.