The enrichment of rare earth from magnesium salt leaching solution of ion-adsorbed type deposit: A waste-free process for removing impurities

Liqing Li; Chenhao Liu; Hepeng Zhang; Bin Huang; Bing Luo; Chao Bie; Xiaoqi Sun

doi:10.1016/j.jenvman.2022.114743

The enrichment of rare earth from magnesium salt leaching solution of ion-adsorbed type deposit: A waste-free process for removing impurities

J Environ Manage. 2022 May 15:310:114743. doi: 10.1016/j.jenvman.2022.114743. Epub 2022 Feb 22.

Authors

Liqing Li¹, Chenhao Liu², Hepeng Zhang², Bin Huang³, Bing Luo⁴, Chao Bie⁴, Xiaoqi Sun⁵

Affiliations

¹ Faculty of Materials Metallurgy and Chemistry, Jiangxi University of Science and Technology, Ganzhou, 341000, PR China.
² Faculty of Materials Metallurgy and Chemistry, Jiangxi University of Science and Technology, Ganzhou, 341000, PR China; CAS Key Laboratory of Design and Assembly of Functional Nanostructures, Fujian Key Laboratory of Nanomaterials, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, PR China; Xiamen Key Laboratory of Rare Earth Photoelectric Functional Materials, Fujian Research Center for Rare Earth Engineering Technology, Xiamen Institute of Rare Earth Materials, Haixi Institute, Chinese Academy of Sciences, Xiamen, Fujian, 361021, PR China.
³ Faculty of Materials Metallurgy and Chemistry, Jiangxi University of Science and Technology, Ganzhou, 341000, PR China; CAS Key Laboratory of Design and Assembly of Functional Nanostructures, Fujian Key Laboratory of Nanomaterials, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, PR China; Xiamen Key Laboratory of Rare Earth Photoelectric Functional Materials, Fujian Research Center for Rare Earth Engineering Technology, Xiamen Institute of Rare Earth Materials, Haixi Institute, Chinese Academy of Sciences, Xiamen, Fujian, 361021, PR China; Jiangxi Province Key Laboratory of Cleaner Production of Rare Earths, Ganjiang Innovation Academy, Chinese Academy of Sciences, Ganzhou, Jiangxi, 341000, PR China; Ganzhou Rare Earth Group Co., Ltd., China Southern Rare Earth, Ganzhou, 341000, PR China.
⁴ CAS Key Laboratory of Design and Assembly of Functional Nanostructures, Fujian Key Laboratory of Nanomaterials, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, PR China; Xiamen Key Laboratory of Rare Earth Photoelectric Functional Materials, Fujian Research Center for Rare Earth Engineering Technology, Xiamen Institute of Rare Earth Materials, Haixi Institute, Chinese Academy of Sciences, Xiamen, Fujian, 361021, PR China.
⁵ CAS Key Laboratory of Design and Assembly of Functional Nanostructures, Fujian Key Laboratory of Nanomaterials, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, PR China; Xiamen Key Laboratory of Rare Earth Photoelectric Functional Materials, Fujian Research Center for Rare Earth Engineering Technology, Xiamen Institute of Rare Earth Materials, Haixi Institute, Chinese Academy of Sciences, Xiamen, Fujian, 361021, PR China; Jiangxi Province Key Laboratory of Cleaner Production of Rare Earths, Ganjiang Innovation Academy, Chinese Academy of Sciences, Ganzhou, Jiangxi, 341000, PR China. Electronic address: xqsun@fjirsm.ac.cn.

PMID: 35217448
DOI: 10.1016/j.jenvman.2022.114743

Abstract

Due to the complex composition of ion-adsorbed type rare earth ore leaching solution, there are challenges in the process of rare earth (RE) separation, such as large RE loss rate, low product purity, radioactive residue and so on. In this article, 8-hydroxyquinoline modified silica gel (HQ-SiO₂) and 2,2'-(1,4-phenylenebis(oxy)) dioctanoic acid (PPBOA) were used to form an efficient process for impurities removal and RE enrichment. Solid phase extraction successfully intercepted 96.7% of the radioactive element thorium. The concentration of aluminium was reduced to 2.14 ppm by frank chromatography. Rare earth elements were enriched from 336.35 mg/L to 237.75 g/L by extraction-precipitation, that is, the enrichment multiple reached more than 700 and the proportion of RE was increased from 21.85% to 96.62%. The loss rate of RE was controlled below 1.59%. Moreover, the magnesium salt leaching solution could be recycled for the leaching of RE ores. Although some liquid waste need to be treated in the processes of HQ-SiO₂ production and regeneration, the integrated process helps to decrease volatile organic solvent, acid-base consumption, wastewater and waste residue. It is an environment-friendly RE enrichment and impurity removal process, which shows application potential in the production field of ion-adsorbed type rare earth mineral products.

Keywords: Extraction; Leaching solution; Rare earth; Separation; Thorium.

MeSH terms

Magnesium*
Metals, Rare Earth* / analysis
Minerals
Recycling / methods
Silicon Dioxide

Substances

Metals, Rare Earth
Minerals
Silicon Dioxide
Magnesium