混合型稀土精矿低温浓硫酸焙烧-水浸过程有价元素的浸出行为  

Leaching Behavior of Valuable Elements in the Low-Temperature Concentrated Sulfuric Acid Roasting-Water Leaching Process of Mixed Rare Earth Concentrates

作　　者：邓永春[1,2,3] 王亮 辛文彬[1,2,3] 沈成 李文博 张小龙 姜银举[1,2,3] 李健飞[1,2,3] 李龙博[1,2,3] DENG Yong-chun;WANG Liang;XIN Wen-bing;SHEN Cheng;LI Wen-bo;ZHANG Xiao-long;JIANG Yin-jun;LI Jian-fei;LI Long-bo(School of Rare Earth Industry(School of Rare Earth Engineering and Technology),Inner Mongolia University of Science and Technology,Baotou 014010,China;Key Laboratory of Green Extraction and Efficient Utilization of Light Rare Earth Resources of Ministry of Education,Inner Mongolia University of Science and Technology,Baotou 014010,China;Clean Extraction and Application of Light Rare Earths Inner Mongolia Autonomous Region Engineering Research Center,Baotou 014010,China;College of Resources and Civil Engineering,Northeast University,Shenyang 110819,China)

机构地区：[1]内蒙古科技大学稀土产业学院(稀土工程技术学院),内蒙古包头014010 [2]内蒙古科技大学轻稀土资源绿色提取与高效利用教育部重点实验室,内蒙古包头014010 [3]轻稀土清洁提取与应用内蒙古自治区工程研究中心,内蒙古包头014010 [4]东北大学资源与土木工程学院,辽宁沈阳110819

出　　处：《稀有金属与硬质合金》2025年第2期1-8,共8页Rare Metals and Cemented Carbides

基　　金：国家重点研发计划项目(2022YFC2905800);一流学科科研专项(YLXKZX-NKD-002,YLXKZX-NKD-008);2023内蒙古自治区直属高校基本科研业务费项目(2023CXPT001);内蒙古自治区自然科学基金项目(2024MS05004,2022QN05017)。

摘　　要：针对高温浓硫酸焙烧工艺处理混合型稀土精矿时存在酸用量大、有酸性气体逸出和放射性渣难处理等问题,开发了低温浓硫酸焙烧-水浸工艺,系统研究了焙烧时间、焙烧温度、酸矿比以及铁磷比对混合型稀土精矿中各元素浸出的影响。结果表明:在焙烧时间60 min、焙烧温度300℃、酸矿比2.0、不调铁磷比的条件下,RE和Th浸出率分别达94.34%、95.05%,显著减少了放射性废渣的生成,但浸出液静置后会有白色沉淀生成,造成浸出液中RE和Th含量下降;通过加入Fe_(2)O_(3)调控焙烧原料中铁磷比至3.0,RE、Th浸出率分别为94.80%、71.20%,有效抑制了浸出液中焦磷酸稀土的析出。结合热力学分析可知,低温(≤300℃)条件下,硫酸与稀土矿物的反应更易进行,且能抑制SO_(2)、SO_(3)酸性气体的排放。相较于高温浓硫酸焙烧法,低温浓硫酸焙烧工艺兼具环境友好性与资源高效性,为混合型稀土精矿绿色提取提供了途径。Aiming at the problems of high acid consumption,acidic gas escape and difficult treatment of radioactive slag in the treatment of mixed rare earth concentrates by high-temperature concentrated sulfuric acid roasting process,a low-temperature concentrated sulfuric acid roasting-water leaching process was developed.The effects of roasting time,roasting temperature,acid-mineral mass ratio and iron-phosphorus mass ratio on the leaching of various elements in the mixed rare earth concentrates were systematically studied.The results show that under the conditions of roasting time of 60 min,roasting temperature of 300℃,acid-mineral mass ratio of 2.0 and without adjusting iron-phosphorus mass ratio,the leaching rates of RE and Th reach 94.34%and 95.05%,respectively,and the formation of radioactive waste residue is significantly reduced.However,white precipitate is generated after the leaching solution stands,resulting in a decrease in the content of RE and Th in the leaching solution.By adding Fe_(2)O_(3) to regulate iron-phospho-rus mass ratio in the roasting raw material to 3.0,the leaching rates of RE and Th are 94.80%and 71.20%,respectively,and the precipitation of rare earth pyrophosphate in the leaching solution is effectively inhibited.According to thermodynamic analysis,under low temperature conditions(≤300℃),the reactions between sulfuric acid and rare earth minerals proceed more readily,and the emission of SO_(2) and SO_(3) acidic gases can be suppressed.Compared with the high-temperature concentrated sulfuric acid roasting method,the low-temperature concentrated sulfuric acid roasting process combines environmental friendliness and resource efficiency,providing a way for the green extraction of mixed rare earth concentrates.

关 键 词：混合稀土精矿 低温浓硫酸焙烧 水浸 铁磷比 钍 

分 类 号：TF845[冶金工程—有色金属冶金]