摘要
风化壳淋积型稀土矿原地浸出时通常采用(NH_(4))_(2)SO_(4)作为浸取剂,存在稀土浸取传质效率低、浸取剂消耗多和浸矿工期长等难题。为解决上述难题,本文将表面活性剂聚乙烯亚胺(PEI)与2.0%(质量分数)的(NH_(4))_(2)SO_(4)进行复配组成复合浸取剂,借助色谱塔板理论探讨风化壳淋积型稀土矿柱式浸取时浸取剂流速、PEI浓度、温度和pH对稀土和铝的浸取传质过程的影响规律。结果表明:复合浸取剂对稀土和铝的浸取传质过程符合Van Deemter方程,PEI的加入能强化(NH_(4))_(2)SO_(4)对稀土和铝的传质过程。随着浸取液温度和pH的增加,稀土和铝浸出时的理论塔板数增大,理论塔板高度(HETP)减小,浸出传质效率增加。考虑到黏土矿物具有较好的pH缓冲性,稀土矿浸取作业时不需要调节浸取液的pH。复合浸取剂浸取稀土和铝的优化传质条件是:(NH_(4))_(2)SO_(4)浓度为2.0%,PEI浓度为0.4%,流速为0.5 mL·min^(-1),夏季作业时可强化稀土浸取的传质效果。
Ammonium sulfate is the common leaching agent used for in-situ leaching of weathered crust elution deposited rare earth ore,which is characterized by low mass transfer efficiency,high leaching agent consumption,and long leaching period.In order to solve the above problems,a surfactant material-polyethyleneimine(PEI)was compounded with 2.0%(mass fraction)ammonium sulfate to form a composite leaching agent,and the effects of flow rate of leaching agent,PEI concentration,temperature,and pH on the mass transfer processes of rare earths and aluminum during column leaching of weathered crust elution-deposited rare earth ore were investigated by applying the chromatographic plate theory.The results show that the mass transfer processes of the composite leaching agent for leaching rare earths and aluminum are in accordance with the Van Deemter equation,and the addition of PEI canstrengthen the mass transfer process of ammonium sulfate for rare earths and aluminum.With the increase of leaching solution temperature and pH,the theoretical plate numbers increase,the HETP decreases and the leaching mass transfer efficiency increasesfor the leaching of rare earths and aluminum.Considering that clay minerals have better pH buffering capacity,pH adjustment is not needed during the rare earth ore leaching operations.The optimal mass transfer conditions for leaching rare earths and aluminum with composite leaching agent are ammonium sulfate concentration of 2.0%(mass fraction),PEI concentration of 0.4%(mass fraction)and flow rate of 0.5 mL·min^(-1),and the mass transfer effects of rare earth leaching during summer operation can be enhanced.
作者
阳慧芳
沙傲阳
徐志高
何正艳
吴晨捷
池汝安
Yang Huifang;Sha Aoyang;Xu Zhigao;He Zhengyan;Wu Chenjie;Chi Ru’an(Key Laboratory for Green Chemical Process of Ministry of Education,School of Resources&Safety Engineering,Wuhan Institute of Technology,Wuhan 430073,China;Key Laboratory of Resources Conversion and Pollution Control of the State Ethnic Affairs Commission,College of Resources and Environmental Science,South-Central Minzu University,Wuhan 430074,China)
出处
《中国稀土学报》
EI
CAS
CSCD
北大核心
2024年第6期1204-1213,I0005,共11页
Journal of the Chinese Society of Rare Earths
基金
国家自然科学基金项目(U2002215)资助。
关键词
风化壳淋积型稀土矿
聚乙烯亚胺
复合浸取剂
浸取
传质
weathered crust elution-deposited rare earth ore
polyethyleneimine
composite leaching agent
leaching
mass transfer
