Wang Qingxiang, Huang Tao, Du Jing, Zhou Lulu
School of Safety Engineering, China University of Mining and Technology, Xuzhou 221116, China.
School of Materials Engineering, Changshu Institute of Technology, Suzhou 215500, China.
ACS Omega. 2022 Jul 6;7(28):24574-24586. doi: 10.1021/acsomega.2c02392. eCollection 2022 Jul 19.
The extraction of uranium (U)-related minerals from raw ore sands via a leaching procedure would produce enormous amounts of tailings, not only causing radioactivity contamination to surroundings but also wasting the potential U utilization. Effective recycling of U from U tailings is propitious to the current issues in U mining industries. In this study, the influence of the composite oxidation of Fe(III) and Mn(VII) intensified by microwave (MW) irradiation on the acid leaching of U from tailings was comprehensively explored in sequential and coupling systems. The U leaching activities from the tailing specimens were explicitly enhanced by MW irradiation. The composite oxidation caused by Fe(III) and Mn(VII) further facilitated the leaching of U ions from the tailing under MW irradiation in two systems. Maximum leaching efficiencies of 84.61, 80.56, and 92.95% for U ions were achieved in the Fe(III)-, Mn(VII)-, and Fe(III)-Mn(VII)-participated coupling systems, respectively. The inappropriateness of the shrinking core model (SCM) demonstrated by the linear fittings and analysis of variance (ANOVA) for the two systems explained a reverse increase of solid cores in the later stage of leaching experiments. The internal migration of oxidant ions into the particle cores enhanced by MW accelerated the dissolution of Al, Fe, and Mn constituents under acidic conditions, which further strengthened U extraction from tailing specimens.
通过浸出程序从原矿砂中提取铀（U）相关矿物会产生大量尾矿，不仅会对周围环境造成放射性污染，还会浪费铀的潜在利用价值。从铀尾矿中有效回收铀有利于解决当前铀矿业面临的问题。在本研究中，在顺序和耦合系统中全面探讨了微波（MW）辐照强化Fe（III）和Mn（VII）的复合氧化对尾矿中铀酸浸出的影响。MW辐照显著提高了尾矿样品中铀的浸出活性。在两个系统中，Fe（III）和Mn（VII）引起的复合氧化在MW辐照下进一步促进了尾矿中铀离子的浸出。在Fe（III）、Mn（VII）和Fe（III）-Mn（VII）参与的耦合系统中，铀离子的最大浸出效率分别达到84.61%、80.56%和92.95%。通过对两个系统的线性拟合和方差分析（ANOVA）证明收缩核模型（SCM）不适用，这解释了浸出实验后期固体核的反向增加。MW增强的氧化剂离子向颗粒核内部的迁移加速了酸性条件下Al、Fe和Mn成分的溶解，这进一步加强了从尾矿样品中提取铀。
