Affiliation:
1. School of Rare Earths, University of Science and Technology of China, Hefei 230026, China
2. Ganjiang Innovation Academy, Chinese Academy of Sciences, Ganzhou 341000, China
3. Jiangxi Province Key Laboratory of Cleaner Production of Rare Earths, Ganzhou 341000, China
Abstract
Due to the coexistence of Al3+ and RE3+ and their similar properties, the separation of aluminum from rare earths is difficult. In this study, selective precipitation was used to separate aluminum from rare earth chloride solution via electrochemical regulated hydrolysis. By controlling the current density and electrolytic time, the rate of hydroxyl ion production was regulated, and the selective separation of rare earth and aluminum was realized according to the different precipitation sequences. By altering the temperature, current density, pH value, and other parameters, the separation performance of aluminum from rare earth in mixed rare earth chloride systems was systematically investigated. The removal rate of aluminum reached 88.35%, and the loss rate of rare earth was only 5.99% under optimized conditions. Compared with traditional neutralization hydrolysis, the new process showed higher efficiency and lower rare earth loss rate. Furthermore, a kinetic analysis of aluminum precipitation revealed that the reaction adhered to pseudo-first order kinetics. Additionally, the precipitate obtained via separation and filtration was amorphous alumina hydroxide with a small amount of rare earth attached. No reagent was consumed for the new process, which was more efficient and cleaner, providing a new idea for removing aluminum impurities from rare earth solutions.
Funder
Natural Science Youth Foundation of Jiangxi Province
General Project of the Key Research and development Program of Ganzhou
Double Thousand Plan of Jiangxi Province
National Natural Science Foundation of China
National Key Research and Development Program of China
Research Projects of Jiangxi Institute of Rare Earths, Chinese Academy of Sciences