中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
Vol. 29 No. 3 March 2019 |
(1. School of Resources and Environmental Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, China;
2. Cooperative Innovation Center of Efficient Development and Application for Ionic Rare Earth Resources, Jiangxi University of Science and Technology, Ganzhou 341000, China;
3. School of Architectural and Surveying and Mapping Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, China;
4. Institute of Applied Chemistry, Jiangxi Academy of Sciences, Nanchang 330029, China)
Abstract:The ion exchange model of the leaching process was determined via batch leaching experiments using the Kerr model, with the selectivity coefficient experimentally determined to be 12.59×10-10 L2/g2. Solute transport laws of ammonium ions (NH4+) and rare earth ions (RE3+) in column leaching were described by the convection-dispersion equation (CDE). The source and sink in the CDE were determined by the Kerr model. The CDE with strong nonlinearity was solved using the sequential non-iterative method. Compared with the breakthrough curve of RE3+, the correlation coefficient between the simulated and experimental curves reached 0.8724. Therefore, this method can simulate the one-dimensional column leaching of weathered crust elution-deposited rare earth ore. Moreover, the effects of different concentrations of ammonium sulfate ((NH4)2SO4) solution on the leaching rate of rare earth were analyzed. The optimal concentration of the (NH4)2SO4 solution had a linear relationship with the rare earth grade.
Key words: weathered crust elution-deposited rare earth ore; column leaching; ion exchange; solute transport