中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 25 No. 11 November 2015 |
（1. National Engineering Research Center for Rare Earth Materials,
General Research Institute for Nonferrous Metals, Beijing 100088, China;
2. GRIREM Advanced Materials Co., Ltd., Beijing 100088, China;
3. School of Chemical Engineering, China University of Petroleum, Beijing 102200）
Abstract:Magnesium sulfate was proposed to be leaching agent to deal with the ion-adsorption type rare earths ore to reduce or even eliminate ammonia-nitrogen emissions. The effects of temperature, particle size and stirring speed on rare earth leaching process and the leaching behaviors of the single rare earth element were investigated in order to reveal the rare earth leaching characteristics. Besides, the comparison of leaching effects between magnesium sulfate and ammonium sulfate was also studied. The results showed thatthe rare earth leaching process could be well described with inner diffusion control model and the apparent activation energy was 9.48 kJ/mol.The leaching behaviors of the single rare earth element were brought into correspondence with rare earths. Moreover, when the concentration of leaching agent was 0.20 mol/L, the rare earth leaching efficiency could all reach above 95% and the leaching efficiency of aluminum impurities could be restrained by 10% using magnesium sulfate compared with ammonium sulfate.
Key words: rare earth; leaching agent; kinetics;magnesium sulfate; ion-adsorption type rare earths ore
