从废FCC催化剂中回收稀土的研究

STUDY ON THE RECOVERY OF RARE EARTH FROM WASTE FCC CATALYST

废FCC催化剂(催化裂化催化剂)中含有2%以上的富La或富ce稀土,用盐酸浸取后可得到含有稀土元素和非稀土杂质的氯化稀土溶液,然后通过溶剂萃取的方法可回收稀土元素。本课题研究了浸取过程中酸的浓度、浸取温度和浸取时间等因素对稀土浸出的影响;考察了用P507(2-乙基己基膦酸单-2-乙基己基酯,HEH/EHP)萃取剂从盐酸介质中萃取回收稀土的方法及影响稀土萃取的主要因素。结果表明,增加浸取酸浓度、升高浸取温度和延长浸取时间均有利于稀土的浸取;采用P507-煤油-盐酸体系可有效地萃取回收浸出液中的稀土元素,较好地实现稀土元素和非稀土杂质的分离。

Waste FCC catalyst contains more than 2% rare earth elements rich in lanthanum or cerium, this rare earth can be leached out by hydrochloric acid to form a solution containing rare earth chloride and some non-RE impurities, and then the rare earth can be recovered by solvent extraction. The effects of acid concentration, leaching temperature and leaching time on the leaching out rate of rare earth are investigated. The method to recover rare earth from the acidic solution using P507 （2-ethylhexyl phosphonic acid mono-2- ethylhexyl, HEH/EHP） extraction agent, and the factors affecting extraction and separation of rare earth are studied. Results show that the leaching out rate of rare earth increases with the increase of hydrochloric acid concentration, leaching temperature and leaching time; the leached out rare earth can be recovered by P507- kerosene-HCl extraction system effectively, and the non-RE impurities can be separated during the process.