杂质铝对磷酸酯混合萃取剂从铵盐浸出液中萃取稀土的影响  

Effect of Aluminum Impurity on Extraction of Rare Earth From Ammonium Salt Leaching Solution with Phosphate Ester Mixed Extractant

作　　者：马驰远 徐珊 徐源来[1] 周芳[1] 池汝安[1] MA Chiyuan;XU Shan;XU Yuanlai;ZHOU Fang;CHI Ru’an(Key of Laboratory for Green Chemical Process of Ministry of Education,School of Chemical Engineering&Pharmacy,Wuhan Institute of Technology,Wuhan 430073,Hubei,China)

机构地区：[1]武汉工程大学化工与制药学院绿色化工过程教育部重点试验室,湖北武汉430073

出　　处：《矿产保护与利用》2020年第2期130-138,共9页Conservation and Utilization of Mineral Resources

基　　金：国家自然科学基金面上基金(51874212);国家自然科学基金重点基金(51734001);国家自然科学基金云南联合基金(U1802252)。

摘　　要：风化壳淋积型稀土矿是我国重要的战略性资源,使用原地浸出开采工艺得到的稀土浸出液中铝含量较高,是主要的杂质离子。为了从该浸出液中一步法分离富集稀土,探讨了一种磷酸酯混合——萃取剂P0261(2-乙基己基磷酸酯,单酯和二酯1GA6FA1混合)在NH4Cl、(NH4)2SO4、NH4NO3三种模拟浸出液中对稀土La3+、Nd3+的萃取行为,并分析杂质铝离子对稀土萃取行为的影响。试验结果表明:在三种铵盐溶液中,萃取剂均能够有效萃取分离稀土离子La3+、Nd3+;加入Al3+后,稀土萃取率E会随Al3+浓度增大而减小。但当Al3+浓度在300 mg·dm-3以内时,E降幅缓慢,最大下降值为14.68%。通过分析负载有机相,Al3+比RE3+更易与P=O形成配位键,且铵根离子浓度变化会影响P=O→RE配位键的形成,从而影响萃取行为。因此,将浸出液中的杂质铝离子浓度控制在300 mg·dm-3以内,则可以使用萃取剂P0261一步法萃取分离稀土。The weathered shell leaching type rare earth ore is an important strategic resource in China.The rare earth leaching solution obtained by in situ leaching process has high content of Al3+and is the main impurity ion.In order to separation rare earth ions from leaching solution by one-step way,the extraction behavior of a phosphate ester extractant,P0261(2-ethylhexyl phosphate,1GA6FA1 mixture of mono ester and diester),was investigated for rare earth ions La3+、Nd3+in three simulated leaching solutions of NH4Cl,(NH4)2SO4 and NH4NO3,and the effect of impurity Al3+on the extraction behavior of rare earth was also analyzed.The results show that the extractant P0261 has good extraction affinity towards rare earth ions La3+and Nd3+in the three kinds of ammonium salts solution.With the addition of Al3+,the extraction rate E of rare earth ions decreases with the increase of Al3+concentration.E declines slowly when C(Al3+)at 0~300 mg·dm-3,while the maximum reduction of E is 14.68%.By analyzed the load organic phase,Al3+was easier to coordination bonds with P=O than RE3+,and the change of NH4+concentration has novel effect on the formation of P=O→RE coordination bonds,which was one of the reasons caused the change of rare earth extraction behavior.From experimental results,control the C(Al3+)below 300 mg·dm-3 in in-situ leaching solution,the effect of impurity ion on selective extraction and separation rare earths by one-step way using extractant P0261 is accepted.

关 键 词：稀土 铝 酸性膦萃取剂 萃取 铵盐 

分 类 号：TF804.2[冶金工程—有色金属冶金]