Affiliation:
1. Key Laboratory for Green Chemical Process of Ministry of Education, School of Resources & Safety Engineering, Wuhan Institute of Technology, Wuhan 430073, China
2. Key Laboratory of Resources Conversion and Pollution Control of the State Ethnic Affairs Commission, College of Resources and Environmental Science, South-Central Minzu University, Wuhan 430074, China
Abstract
In the process of the in situ leaching of weathered crust elution-deposited rare earth ores (WCE-DREOs), there are many problems in the conventional leaching agent, such as a slow leaching rate, low leaching yield and long leaching period. In order to solve the above problems, 2.0 wt% ammonium sulfate was mixed with hydroxypropyl methyl cellulose (HPMC). The effects of the HPMC concentration, temperature, pH and flow rate on the leaching kinetics of rare earth (RE) and aluminum (Al) were investigated. The results showed that when the concentration of HPMC was 0.05 wt%, the leaching equilibrium time of RE and Al was about 60% shorter than that of single ammonium sulfate. With an increase in the leaching temperature, the leaching equilibrium time of RE and Al decreased, and the apparent activation energy of RE and Al was 23.13 kJ/mol and 17.31 kJ/mol, respectively. The leaching process was in line with the internal diffusion kinetic control model. When the pH of the leaching agent was 4.02~8.01, the leaching yield of RE and Al was basically the same, but the leaching yield of Al was greatly increased at pH 2.0 due to a large amount of adsorbed hydroxy-Al in the RE ore eluded. The leaching yield reached the maximum when the flow rate was 0.7 mL/min. The leaching time and the leaching cost of RE can be saved by the composite leaching agent. The results provide theoretical guidance for the development and industrial application of the new composite leaching agent.
Funder
National Natural Science Foundation of China
National Key Research and Development Program of China
Subject
Geology,Geotechnical Engineering and Engineering Geology
Reference18 articles.
1. Recent advances in selective separation technologies of rare earth elements: A review;Chen;J. Environ. Chem. Eng.,2021
2. Flotation-magnetic separation for the beneficiation of rare earth ores;Xiong;Miner. Eng.,2018
3. Zeng, X., Zeng, B., Huang, L., Zhong, L., Li, X., and Huang, W. (2022). Adsorption of Y (III) on the Interface of Kaolinite-H2O: A DFT Study. Minerals, 12.
4. Ultrasound-assisted leaching of rare earths from the weathered crust elution-deposited ore using magnesium sulfate without ammonia-nitrogen pollution;Yin;Ultrason. Sonochem.,2018
5. Development of rare earth hydromet-allurgy technology in China;Huang;J. Rare Earths,2005