摘要
以内蒙某砂岩铀矿床为研究对象,通过不同酸度梯度及有无氧化剂的酸法搅拌浸铀试验,系统分析了铀浸出特征、动力学作用及杂质元素浸出特征,旨在为后续现场试验的工艺选择提供数据支撑。研究结果表明:铀浸出过程呈现显著的阶段性特征,即浸出液铀浓度与铀浸出速率随浸出时间推进,先进入快速上升阶段,随后上升趋势放缓并逐渐趋于稳定;特定范围内提高浸出剂酸度或添加氧化剂可显著提升铀浸出效率,且酸度随浸出时间的延长而降低,表明矿石中碱性物质与铀的浸出消耗了大量硫酸;铀浸出动力学过程符合收缩未反应核模型,主要受固体或产物层扩散控制,酸度与氧化剂是影响铀浸出动力学作用的关键因素。矿石中钾、钙、钠、镁、铁、硅等矿物溶解,导致浸出液中相应杂质含量大幅升高。总铁是浸出液中浓度最高的杂质组分,最高浓度达1312.91 mg/L;钙镁离子最高浓度分别为840.48、428.10 mg/L。在10 g/L酸度且添加氧化剂的条件下,渣计铀浸出率为91.90%,吨铀酸耗为186.00 t,浸出效果达最优水平,可作为现场试验推荐酸度。但因矿石钙镁含量较高,含矿层可能因石膏沉淀堵塞。
This study focused on a sandstone uranium mine situated in Inner Mongolia,China.In order to systematically characterize uranium leaching,a series of leaching experiments were conducted using acid solutions with different acidity gradients,under two experimental conditions:in the presence and absence of oxidants.Additionally,the study elucidates the intrinsic kinetic mechanisms governing the leaching process and examines the leaching behavior of impurity elements involved.The objective is to provide comprehensive data support for the selection of processes in upcoming field trials at this uranium deposit.The results show that the uranium leaching process demonstrates distinct stage characteristics,marked by the evolution of uranium concentration in the leaching solution and the uranium leaching rate over time.Initially,a phase of rapid increase is observed,which is subsequently followed by a gradual deceleration in the upward trend that ultimately culminated in stabilization.Moreover,either increasing the acidity of the leaching agent or incorporating oxidants within a specific range could significantly enhance the uranium extraction efficiency.Throughout the leaching process,the acidity exhibites a gradual decline over time,which indicates that the alkaline components in the ore and uranium leaching consumes a substantial amount of sulfuric acid during the uranium extraction procedure.Kinetic analysis reveales that the uranium leaching process conforms to the shrinking core model,and its reaction rate is primarily controlled by the diffusion through the solid matrix or the formed product layer.The acidity and oxidants are critical factors influencing the kinetic mechanisms of uranium leaching.Furthermore,the dissolution of minerals containing elements such as potassium(K),calcium(Ca),sodium(Na),magnesium(Mg),iron(Fe),and silicon(Si)in the ore lead to a significant increase in the concentrations of the corresponding impurities in the leaching solution.The total iron is identified as the impurity component with the highest concentration in the leaching solution,reaching a peak concentration of 1312.91 mg/L.The maximum concentrations of calcium and magnesium ions are recorded at 840.48 mg/L and 428.10 mg/L,respectively.Under the conditions of 10 g/L acidity and oxidant addition,the uranium leaching rate from the residue is 91.90%,accompanied by a sulfuric acid consumption of 186.00 tons per ton of extracted uranium.Therefore,the leaching performance reaches optimal levels,establishing it as a recommended acidity for field trials.Nevertheless,given the high calcium and magnesium content in the ore,there is a potential risk that gypsum precipitation may lead to blockages in the mineralized layer.
作者
王健
林泳钊
申怡梦
段和军
徐广明
荣建锋
孙占学
黎广荣
徐玲玲
柯平超
周义朋
WANG Jian;LIN Yongzhao;SHEN Yimeng;DUAN Hejun;XU Guangming;RONG Jianfeng;SUN Zhanxue;LI Guangrong;XU Lingling;KE Pingchao;ZHOU Yipeng(National Key Laboratory of Uranium Resources Exploration-Mining and Nuclear Remote Sensing,East China University of Technology,Nanchang 330013,China;Jiangxi Provincial Key Laboratory of Genesis and Remediation of Groundwater Pollution,Nanchang 330013,China;School of Water Resources and Environment Engineering,East China University of Technology,Nanchang 330013,China;CGNPC Uranium Resources Co.,Ltd.,Beijing 100048,China;China National Nuclear Corporation Inner Mongolia Energy Co.,Ltd.,Huhhot 014010,China)
出处
《有色金属(冶炼部分)》
北大核心
2025年第12期109-122,共14页
Nonferrous Metals(Extractive Metallurgy)
基金
铀资源探采与核遥感全国重点实验室(东华理工大学)自主部署项目(2024QZ-TD-22)
国家自然科学基金重点项目(42430716)
国家自然科学基金面上项目(42272307)
国家核设施退役及放射性废物治理科研项目(1276)
江西省重点研发计划项目(20232BBG70007)
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(2023NRE-LH-15,2023NRE-LH-19)。
关键词
砂岩铀矿床
酸法浸铀
铀浸出率
动力学特征
杂质元素
sandstone uranium deposit
uranium acid leaching
uranium leaching rate
dynamic characteristics
impurity elements
