摘要
CO_(2)+O_(2)地浸工艺是我国第三代铀矿采冶技术,地浸过程中溶浸液与含矿层矿物反应后,在将铀从矿石中浸出的同时,由于地下水矿化度增高又会产生化学沉淀,导致含矿层堵塞。CaCO_(3)沉淀是CO_(2)+O_(2)地浸采铀过程中含矿层堵塞的重要原因。为探索CaCO_(3)沉淀堵塞条件,根据内蒙古纳岭沟铀矿CO_(2)+O_(2)浸铀过程中浸出液化学成分数据,通过水文地球化学模拟,对含矿层堵塞的水文地球化学条件进行了系统研究。结果表明,CaCO_(3)沉淀是造成CO_(2)+O_(2)地浸中含矿层化学堵塞的重要原因。当溶浸液pH>6.5时,CaCO_(3)将发生沉淀,溶浸液的pH、HCO_(3)^(-)浓度、Ca^(2+)浓度是影响CaCO_(3)沉淀的主要因素,过高的pH与HCO_(3)^(-)浓度、Ca^(2+)浓度都会造成CaCO_(3)沉淀的产生。根据模拟结果获得了不产生CaCO_(3)沉淀条件下pH、HCO_(3)^(-)浓度、Ca^(2+)浓度三者之间的关系,并由此认为,维持溶浸液较低的Ca^(2+)浓度与较低的pH是预防与缓解CaCO_(3)沉淀堵塞的有效途径。
CO_(2)+O_(2)in-situ leaching of uranium process is the third generation of uranium mining and metallurgical technology in China,during the in-situ leaching process,the dissolved liquid reacts with the ore-bearing seam minerals to extract uranium from the ore,at the same time,chemical precipitation will occur due to the increase of groundwater mineralization,resulting in ore-bearing seam blockage.CaCO_(3)precipitation is an important cause of ore layer blockage during in uranium leaching in CO_(2)+O_(2).In order to explore the conditions of CaCO_(3)precipitation and blockage,the hydrogeochemical conditions of ore-bearing seam blockage were systematically studied through hydrogeochemical simulation,according to the chemical composition data of CO_(2)+O_(2)uranium leaching solution from uranium ore in Nalinggou in Inner Mongolia.The results show that CaCO_(3)precipitation is the important cause of chemical blockage of ore-bearing seams in CO_(2)+O_(2)in-situ leaching of uranium.When the pH value of the leaching solution 6.5 above,CaCO_(3)will precipitate,the pH value,concentration of HCO_(3)^(-)and Ca^(^(2+))of the immersion solution are the main factors affecting CaCO_(3)precipitation,and excessive pH value and concentration of HCO_(3)^(-)and Ca^(^(2+))will cause the production of CaCO_(3)precipitation.According to the simulation results,the relationship between pH value,and concentrations of HCO_(3)^(-)and Ca^(^(2+))without CaCO_(3)precipitation is obtained,and it is concluded that maintaining the lower Ca^(^(2+))concentration and lower pH value of the leaching solution is an effective way to prevent and alleviate CaCO_(3)precipitation blockage.
作者
杨诗琪
刘金辉
阳奕汉
李鹏
张传飞
李光辉
徐奇
陈婷
YANG Shi-qi;LIU Jin-hui;YANG Yi-han;LI Peng;ZHANG Chuan-fei;LI Guang-hui;XU Qi;CHEN Ting(School of Water Resources and Environmental Engineering,East China University of Technology,Nanchang 330013,China;CNNC Inner Mongolia Mining Co.,Ltd.,Huhhot 010010,China)
出处
《有色金属（冶炼部分）》
CAS
北大核心
2023年第8期50-59,共10页
Nonferrous Metals（Extractive Metallurgy)
基金
中国铀业有限公司-东华理工大学核资源与环境国家重点实验室联合创新基金项目(NRE2021-17)
国家自然科学基金核技术创新联合基金资助项目(U1967209)。
