采用HF和HClO_4从铀尾矿中浸出铀的试验研究  

Extraction of uranium from uranium tailings by acid leaching with HF and HClO_4

作　　者：李密[1,2] 黄婧[1] 戴士祥 张晓文[1,2] 张彪[1] 丁德馨[3] 

机构地区：[1]南华大学环境保护与安全工程学院,湖南衡阳421001 [2]南华大学放射性三废处理与处置重点实验室,湖南衡阳421001 [3]南华大学铀矿冶生物技术国防重点学科实验室,湖南衡阳421001

出　　处：《中国矿业大学学报》2016年第3期639-645,共7页Journal of China University of Mining & Technology

基　　金：国家自然科学基金项目(51404141);湖南省科技计划项目(2015RS4039);中国博士后科学基金项目(2015M572255);衡阳市科学技术发展计划项目(2014KS32)

摘　　要：为了从低品位铀尾矿中回收铀资源,在详细分析了铀尾矿工艺矿物学性质的基础上,提出了以硫酸为浸出剂,HF和HClO_4为强化剂的氧化强化浸铀工艺,研究了工艺参数对铀浸出的影响,并通过X射线衍射仪、激光粒度仪及扫描电镜等手段分析铀尾矿浸出过程中的物相、粒度及形貌特征变化,揭示了HF和HClO_4对铀尾矿浸出的强化作用机理.研究结果表明:HF可分解硅酸盐类矿物结构,而HClO_4可对脉石颗粒表面造成"溶蚀",二者均可促进脉石颗粒与铀的解离,但HClO_4的作用效果低于HF.当浸出温度为50℃,硫酸浓度为1.5mol/L,浸出时间为80min,液固质量比为12时,HF和HClO4对铀的浸出率分别为96%和78%.Based on the fric acid with HF and process mineralogy of uranium tailings, extraction of uranium using sul- HClO4 as oxidant agents were proposed to recover uranium resources from uranium tailings. Technological parameters affecting the extraction rate were investiga- ted. Besides, the strengthening mechanism of HF and HClO4 during leaching process were re- vealed by analyzing the variety of phase transformation, particle size distribution and morphol- ogy features in residues through X-ray difraction, laser particle analyzer and scanning electron microscrope. Results indicate that both HF and HC104 have positive effect on improving disso- ciation between gangue and uranium. The uranium extraction rate by HF is higher than that of HClO4. Specifically, HF can decompose silicate minerals structure and reduce the particle size, while HClO4 can cause significant corrosion at the surface of gangue particles. Uranium extrac- tion rate of 96% and 780/oo were obtained by HF and HClO4 respectively with temperature of 50℃ , H2SO4 concentration of 1.5 mol/L, leaching time of 80 min and liquid/solid ratio of 12.

关 键 词：铀尾矿 浸出 强化机理 脉石 

分 类 号：TD983[矿业工程—选矿]