(1. 江西理工大学 冶金与化学工程学院，赣州 341000；
2. 河南省冶金研究所有限责任公司，郑州 450053)
摘 要: 针对离子吸附型稀土矿浸出液中铝元素含量高、对稀土后续分离影响大的问题，本研究以3,5-二硝基水杨酸(DNS)作为有机配体，以硅胶作为基体材料，通过化学合成3,5-二硝基水杨酸化学键合硅胶进行吸附除铝研究。结果表明：当3,5-二硝基水杨酸与Al3+的配位比为1:1、溶液pH=3.5、3,5-二硝基水杨酸改性硅胶用量为2 g时，溶液中Al3+去除率达90%以上，稀土几乎无损失。采用紫外吸收的方法对机理进行研究，结果显示稀土料液中的Al3+通过取代3,5-二硝基水杨酸分子中羟基上的H+与其形成络合物，进而实现稀土与铝的分离。由吸附动力学研究可知，3,5-二硝基水杨酸改性硅胶对Al3+的吸附符合二级吸附动力学模型，其R2为0.98813。
关键字: 稀土；除铝；3,5-二硝基水杨酸；改性硅胶；选择性配位
（1. School of Metallurgy and Chemical Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, China;
2. Henan Institute of Metallurgy Co., Ltd., Zhengzhou 450053, China）
Abstract:In view of the high content of aluminum in leaching solution obtained by ion-adsorption rare earth mining and the great influence on the subsequent separation of rare earths, silica gel as the basic material was modified with 3,5-dinitrosalicylic acid (DNS) as the organic ligand through chemical synthesis, which was used for adsorption and aluminum removal from leaching solution of RE. The results show that when the coordination ratio of 3,5-dinitrosalicylic acid to Al3+ is 1:1 , the solution pH value is 3.5 and the amount of the modified silica gel with DNS is 2 g, the Al3+ removal rate is over 90%, and the RE loss is 0% nearly. The results of UV spectrum analysis show that Al3+ can form a complex through replacing of H+ on the hydroxyl group of the DNS, which achieves the separation of Al3+ and RE3+. According to the study of adsorption kinetics, the adsorption of aluminum ions by modified silica gel with DNS conforms to the second-order adsorption kinetics model, and its R2 is 0.98813.
Key words: rare earth; aluminum removal; 3,5-dinitrosalicylic acid; modified silica gel; selective coordination
