Recovery of rare earths from spent FCC catalysts by solvent extraction using saponified 2-ethylhexyl phosphoric acid-2-ethylhexyl ester（EHEHPA）
来源期刊：Journal of Rare Earths2017年第7期
论文作者：叶思施 靖宇 王运东 费维扬
文章页码：716 - 722
摘 要：A process to recover rare earth（RE） metals from spent fluid catalytic cracking（FCC） catalysts by solvent extraction was studied, using saponified 2-ethylhexyl phosphoric acid-2-ethylhexyl ester（EHEHPA or P507）. The recovery process involved three steps:（1） leaching REs（mainly lanthanum and cerium）;（2） solvent extraction by applying saponified P507-kerosene system;（3） stripping. Experiments to assure optimal operating conditions were conducted. Results indicated that RE metals could be recovered effectively from spent catalyst with saponified P507-kerosene-HCl system. At room temperature of 25 oC, 10 g spent catalyst with 110 m L of HCl（1 mol/L） could achieve a leaching efficiency of 85%. For extraction, initial pH value of 3.17, organic/aqueous ratio（O/A ratio） of 2:1 with an extractants’ saponification rate of 20% could obtain 100% efficiency. In the stripping process, 1 mol/L HCl with O/A ratio of 1:1 led to a stripping efficiency of 96%. In the present study, RE metals from spent FCC catalysts were effectively recovered, which avoided wasting a large amount of RE resources. It provides a theoretical support for commercial recycling of RE resources.
叶思施，靖宇，王运东，费维扬
The State Key Laboratory of Chemical Engineering, Department of Chemical Engineering, Tsinghua University
摘 要：A process to recover rare earth（RE） metals from spent fluid catalytic cracking（FCC） catalysts by solvent extraction was studied, using saponified 2-ethylhexyl phosphoric acid-2-ethylhexyl ester（EHEHPA or P507）. The recovery process involved three steps:（1） leaching REs（mainly lanthanum and cerium）;（2） solvent extraction by applying saponified P507-kerosene system;（3） stripping. Experiments to assure optimal operating conditions were conducted. Results indicated that RE metals could be recovered effectively from spent catalyst with saponified P507-kerosene-HCl system. At room temperature of 25 oC, 10 g spent catalyst with 110 m L of HCl（1 mol/L） could achieve a leaching efficiency of 85%. For extraction, initial pH value of 3.17, organic/aqueous ratio（O/A ratio） of 2:1 with an extractants’ saponification rate of 20% could obtain 100% efficiency. In the stripping process, 1 mol/L HCl with O/A ratio of 1:1 led to a stripping efficiency of 96%. In the present study, RE metals from spent FCC catalysts were effectively recovered, which avoided wasting a large amount of RE resources. It provides a theoretical support for commercial recycling of RE resources.
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