Adsorption ability of rare earth elements on clay minerals and its practical performance

• Published in: Journal of rare earths Vol. 34; no. 5; pp. 543 - 548
• Main Author: 肖燕飞 黄莉 龙志奇 冯宗玉 王良士
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.05.2016
• Subjects: adsorption ability; column leaching; deposit characteristics; rare earth; 吸附性能; 吸附等温模型; 实用性能; 浸出过程; 离子吸附型; 粘土矿物; 重稀土元素; 饱和吸附容量; rare earth; column leaching; adsorption ability; deposit characteristics
• ISSN: 1002-0721; 2509-4963
• DOI: 10.1016/S1002-0721(16)60060-1

The adsorption behaviors of rare earth elements on clay minerals would have great influence on the mineralization process and the leaching process of the ion-adsorption type rare earths ore.In this work,the adsorption thermodynamics of REEs on kaolin were investigated thoroughly and systematically.The experimental results showed that the adsorption characteristics of La,Nd,Y on kaolin did fit well with the Langmuir isotherm model and their saturated adsorption capacities were 1.731,1.587 and 0.971 mg/g,respectively.The free energy change（ΔG）values were –16.91 kJ/mol（La）,–16.05 kJ/mol（Nd）and –15.58 kJ/mol（Y）,respectively.The negative values of ΔG demonstrated that the adsorption of rare earth on kaolin was a spontaneously physisorption process.The deposit characteristic of the volcanic ion-adsorption type rare earths ore and the behavior of the rare earth in the column leaching process were also developed here.With the increase of the ore body depth,the distribution of the LREEs decreased and the HREEs increased.And the slight differences in the adsorption ability of REEs on clay minerals led to the fractionation effect in the column leaching process.These developed more evidences and better understanding of metallogenic regularity,and provided a theoretical basis and scientific approach to separation of the HREEs and LREEs in the leaching process.