Reduction leaching of rare earth from ion-adsorption type rare earths ore with ferrous sulfate

• Published in: Journal of rare earths Vol. 34; no. 9; pp. 917 - 923
• Main Author: 肖燕飞 冯宗玉 胡谷华 黄莉 黄小卫 陈迎迎 龙志奇
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.09.2016
• Subjects: ferrous sulfate; rare earth; reduction leaching; the ion-adsorption type rare earths ore; 浸出过程; 环境友好型; 硫酸亚铁; 离子吸附型; 稀土矿石; 稀土铈; 还原浸出; （NH4）2SO4; reduction leaching; ferrous sulfate; rare earth; the ion-adsorption type rare earths ore
• ISSN: 1002-0721; 2509-4963
• DOI: 10.1016/S1002-0721(16)60115-1

The practice ofin-situ leaching of the ion-adsorption type rare earths ore with ammonium sulfate could only leach most of rare earth in ion-exchangeable phase, but not the colloidal sediment phase. Therefore, the reduction leaching of rare earth from the ion-adsorption type rare earths ore with ferrous sulfate was innovatively put forward. The soak leaching process and the column leaching process were investigated in the present study. It was determined that ion-exchangeable phase could be released, and part of colloidal sediment phase rare earth could be reduction leached by the cations with reduction properties. The mechanism of reduction leaching was discussed with the Eh-pH diagram of cerium. Moreover, the stronger reduction of reductive ions, the greater acidity of leaching agent solution, and the higher reductive ion concentration, could result in the higher rare earth efficiency and the bigger ce-rium partition in the leaching liquor. In the ferrous sulfate column leaching process, the rare earth leaching rate and the rare earth effi-ciency were a little higher than with （NH4）2SO4 agent, and the rare earth efficiency and the partitioning of cerium in leaching liquor could be about 102% and 5.31%, respectively. However, the ferrous sulfate leaching process revealed some problems, so compound leaching with magnesium sulfate and a small amount of ferrous sulfate was proposed to an excellent alternative leaching agent for further studies, which may realize efficiency extraction and be environment-friendly.