稀土浸出液氧化钙沉淀-氢氧化钠搅洗工艺  

Calcium oxide precipitation and sodium hydroxide stirring washing process of rare earth leaching liquor

作　　者：陈昕 彭彬 谭传满 徐志磊 肖燕飞[1,2,3] CHEN Xin;PENG Bin;TAN Chuan-man;XU Zhi-lei;XIAO Yan-fei(Faculty of Materials Metallurgy and Chemistry,Jiangxi University of Science and Technology,Ganzhou 341000,China;Ganzhou Engineering Technology Research Center of Green Metallurgy and Process Intensification,Jiangxi University of Science and Technology,Ganzhou 341000,China;Key Laboratory of Ionic Rare Earth Resources and Environment,Ministry of Natural Resources,Jiangxi University of Science and Technology,Ganzhou 341000,China)

机构地区：[1]江西理工大学材料冶金化学学部,赣州341000 [2]江西理工大学、赣州市绿色冶金与过程强化工程技术研究中心,赣州341000 [3]江西理工大学、自然资源部离子型稀土资源与环境重点实验室,赣州341000

出　　处：《中国有色金属学报》2023年第9期3023-3032,共10页The Chinese Journal of Nonferrous Metals

基　　金：国家重点研发计划资助项目(2021YFC2902202,2020YFC1909002);国家自然科学基金资助项目(52274351,51964018);江西省“双千计划”科技创新高端人才(青年)项目(JXSQ2019201116);江西省青年井冈学者奖励计划项目(QNJG2019056);江西省离子型稀土资源绿色开发与高值利用国家重点实验室培育计划资助项目(20194AFD44003)。

摘　　要：为解决稀土浸出液除杂过程稀土损失大和氧化钙沉淀所得稀土沉淀产物中硫酸根含量高的问题,本文提出了稀土浸出液氧化钙沉淀-氢氧化钠搅洗新工艺,即采用氧化钙直接沉淀稀土浸出液获得稀土沉淀产物,避免了除杂过程稀土损失;再采用氢氧化钠对沉淀产物进行搅洗,可有效去除稀土沉淀产物中的硫酸根和铝杂质。结果表明:在氧化钙沉淀稀土浸出液的过程中,碱式硫酸稀土和氢氧化铝的生成使混合稀土氧化物中SO_(4)^(2-)以及Al_(2)O_(3)含量分别高达21.68%和13.99%(质量分数)。在最佳条件下搅洗可获得稀土纯度为95.70%,氧化铝和硫酸根含量分别为2.04%和0.18%的混合稀土氧化物。此外,氢氧化钠搅洗滤液可以循环使用;而滤液中的铝元素可通过二氧化碳碳化法进行回收,最终得到的氧化铝呈颗粒状,纯度达到99%以上。In order to solve the problems of big rare earth loss in the impurity removal process from rare earth leaching liquor and high sulfate content in the rare earth precipitates obtained by calcium oxide precipitation,the calcium oxide precipitation and sodium hydroxide stirring washing process of rare earth leaching liquor was proposed.In the new process,calcium oxide was used to directly precipitate the rare earth leaching liquor to obtain rare earth precipitates,which avoids the loss of rare earth in the impurity removal process.And then sodium hydroxide was used to stirring washing the precipitates,which can effectively remove sulfate and aluminum impurities,and avoid the loss of rare earth.The results show that the content of SO_(4)^(2-) and Al_(2)O_(3) in the mixed rare earth oxide are as high as 21.68%and 13.99%,respectively,due to the formation of basic rare earth sulfate and aluminum hydroxide during the precipitation of rare earth leaching liquor with calcium oxide.Under the optimum stirring washing conditions,the mixed rare earth oxides with the purity of 95.70%can be obtained,and the content of alumina and sulfate are 2.04%and 0.18%,respectively.In addition,the washing filtrate of sodium hydroxide can be recycled.The aluminum element in the washing filtrate is recovered by carbon dioxide carbonization method,and the obtained Al_(2)O_(3) is in granular form with a purity of more than 99%.

关 键 词：稀土浸出液 氧化钙沉淀 氢氧化钠搅洗 碱式硫酸稀土 铝酸钠 

分 类 号：TF845[冶金工程—有色金属冶金]