蒙其古尔铀矿床中性地浸中黄铁矿的工艺矿物学变化特征以及对浸出效率的影响  

CHANGES OF PROCESS MINERALOGY OF PYRITE AND THE IMPACT ON IN-SITU NEUTRAL LEACHING EFFICIENCY FROM THE MENGQIGUER URANIUM DEPOSIT

作　　者：许喜凤 宋昊[1,2,3] 范元清 张成江 谭亚辉[4] XU Xifeng;SONG Hao;FAN Yuanqing;ZHANG Chengjiang;TAN Yahui(Chengdu University of Technology,Chengdu,Sichuan 610059,China;State Key Laboratory of Geohazard Prevention and Geoenvironment Protection,Chengdu,Sichuan610059,China;Applied Nuclear Techniques in Geosciences Key Laboratory of Sichuan Province,Chengdu,Sichuan 610059,China;Beijing Research Institute of Chemical Engineering and Metallurgy,Beijing 101149,China)

机构地区：[1]成都理工大学,四川成都610059 [2]地质灾害防治与地质环境保护国家重点实验室,四川成都610059 [3]地学核技术四川省重点实验室,四川成都610059 [4]核工业北京化工冶金研究院,北京101149

出　　处：《矿物岩石》2024年第1期101-108,共8页Mineralogy and Petrology

基　　金：国家自然科学基金项目(批准号:42173072,U1967207);成都理工大学珠峰科学研究计划(项目编号:2021ZF11413)。

摘　　要：黄铁矿是砂岩型铀矿中普遍存在的矿物之一,其在中性CO_(2)+O_(2)浸出前后矿物学变化特征是确定地浸采铀工艺相关参数以及正确评价地浸开发前景的重要依据。本次研究以伊犁盆地蒙其古尔砂岩型铀矿床为研究对象,对矿床中含矿段样品进行中性(CO_(2)+O_(2))浸出加压搅拌试验,并使用TIMA、SEM-EDS对该矿床矿石浸出前后黄铁矿的工艺矿物学变化特征进行研究。原矿石中黄铁矿具有较完整的晶形,与石英、铀石共生,而在浸出反应后,黄铁矿的含量由0.46%减少到0.01%,小于20μm的黄铁矿颗粒的占比由21.77%增加到55.89%,解离度在50%以上的黄铁矿占比由58.54%减少为26.25%,黄铁矿发生溶解仅在石英、长石等矿物颗粒内部的孔隙中有少量的残留。研究表明蒙其古尔铀矿床中存在的黄铁矿对地浸采铀是有利的。但黄铁矿中的负一价硫更容易与氧气发生反应,消耗一定量的氧气导致黄铁矿溶解缓慢,致使铀浸出中氧气消耗量增加。因此,在实际地浸中建议开发可以优先与黄铁矿反应的氧化剂,既可以降低地浸开采成本,也可提高铀的浸出效率。Pyrite is one of the most prevalent minerals in sandstone-type uranium deposits.Investigating the mineralogy of pyrite before and after CO_(2)+O_(2)neutral leaching holds significant importance for determining uranium leaching parameters and evaluating the prospect of uranium leaching exploitation.Focusing on the Mengqiguer sandstone-type uranium deposit in the Yili Basin,this study conducts a neutral(CO_(2)+O_(2))pressure stirring test on ore-bearing samples from the deposit.The technological mineralogy characteristics of pyrite before and after leaching are analyzed using TIMA and SEM-EDS.The findings reveal that pyrite in the raw ore exhibits a relatively complete crystalline form and is associated with quartz and coffinite.Post-leaching,pyrite undergoes dissolution,resulting in a decrease in its content from 0.46%to 0.01%.Furthermore,the proportion of pyrite particles smaller than 20μm increases significantly from 21.77%to 55.89%.The percentage of pyrite with a dissociation degree exceeding 50%decreases from 58.54%to 26.25%,leaving only a small amount of uranium in the pores within quartz,feldspar,and other mineral particles.This indicates that the pyrite present in the Mengqiguer uranium deposit is conducive to in-situ leaching of uranium.However,the divalent sulfur in pyrite is prone to reacting with oxygen,consuming a considerable amount of oxygen,resulting in the sluggish dissolution of pyrite and an increase in oxygen consumption during uranium leaching.Therefore,the development of an oxidizer that can selectively react with pyrite in actual in-situ leaching is crucial to reduce the cost of in-situ leaching and enhance uranium leaching efficiency.

关 键 词：蒙其古尔铀矿床 工艺矿物学 中性浸出 黄铁矿 

分 类 号：TD868[矿业工程—金属矿开采]