期刊
MINERALS ENGINEERING
卷 182, 期 -, 页码 -出版社
PERGAMON-ELSEVIER SCIENCE LTD
DOI: 10.1016/j.mineng.2022.107564
关键词
Rare earth elements; High temperature reaction; Deep eutectic solvents; Selective extraction; Monazite; Electrodissolution
资金
- NERC Minerals Security of Supply, SoS RARE grants [NE/M011429/1, NE/M011267/1, NE/M01147X/1]
- Tellurium and Selenium Cycling and Supply (TeaSe) grant [NE/M010848/1]
- NERC's Catalyst Grant [NE/L002280/1]
- Ministry of Science, Innovation and University of Spain [BEAGAL18/00079]
- NERC [NE/L002280/1] Funding Source: UKRI
The physico-chemical changes occurring during the high-temperature phase transformation of monazite in the presence of Na2CO3 at 1000 C for 2 h duration at monazite: Na2CO3 ratios between 1.0 and 5.0 were investigated. The formation of sodium lanthanide phosphates was prevalent above a monazite:alkali ratio of 2, however, below this ratio, the dephosphorization of monazite as Na3PO4 and Ce(1-x)Ln(x)O(2-x/2) solid solutions occur offering unique selectivity for rare-earth oxide separation from the mineral matrix. Cyclic voltammetry of pure CeO2, La2O3, Nd(2)O3, and PrO2/Pr2O3 was carried out in the deep eutectic solvent Ethaline (1:2 mixture of choline chloride and ethylene glycol) proving the electrochemical activity of these oxides. Electrodissolution of pure oxides and water-leached monazite after high-temperature reaction with a ratio of 1:1 was carried out in a 0.1 mol/L glucose solution in Ethaline showing a preferential solubility of 23.85% for pure Nd2O3. In contrast, pure oxides of CeO2, La2O3 and PrO2/Pr2O3 were found to be insoluble. We also observed that electrodissolution of the water leached monazite was not possible because of the inert behaviour of Ce(1-x)Ln(x)O(2-x/2) solid solutions. Avoiding cerium oxidation during the high-temperature process will lead to a method for further selectivity for rare-earth oxide processing using staged electro-chemical winning of oxides.
The physico-chemical changes occurring during the high-temperature phase transformation of monazite in the presence of Na2CO3 at 1000 C for 2 h duration at monazite: Na2CO3 ratios between 1.0 and 5.0, were investigated. The formation of sodium lanthanide phosphates was prevalent above a monazite:alkali ratio of 2, however, below this ratio, the dephosphorization of monazite as Na3PO4 and Ce(1-x)Ln(x)O(2-x/2) solid solutions occur offering unique selectivity for rare-earth oxide separation from the mineral matrix. Cyclic voltammetry of pure CeO2, La2O3, Nd(2)O3, and PrO2/Pr2O3 was carried out in the deep eutectic solvent Ethaline (1:2 mixture of choline chloride and ethylene glycol) proving the electrochemical activity of these oxides. Electrodissolution of pure oxides and water-leached monazite after high-temperature reaction with a ratio of 1:1 was carried out in a 0.1 mol/L glucose solution in Ethaline showing a preferential solubility of 23.85% for pure Nd2O3. In contrast, pure oxides of CeO2, La2O3 and PrO2/Pr2O3 were found to be insoluble. We also observed that electrodissolution of the water leached monazite was not possible because of the inert behaviour of Ce(1-x)Ln(x)O(2-x/2) solid solutions. Avoiding cerium oxidation during the high-temperature process will lead to a method for further selectivity for rare-earth oxide processing using staged electro-chemical winning of oxides.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据