Abstract: Vanadium was selectively extracted from the Fe-containing acid leaching solution of waste fluid catalytic cracking (FCC) catalyst by controlled equilibrium time of extraction method using 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester (P507) as the extraction agent. The test results showed that using the co-extraction system composing of 10% of P507, 5% of tributyl phosphate（TBP）, and 85% of sulfonated kerosene,under the conditions of a saponification rate of extraction agent of 50%, an extraction ratio of 1:1 and an extraction equilibrium time of 10 min, the extraction rate of vanadium reached 99.5% after five-stage countercurrent extraction, and the extraction rate of iron was only 5.2%. Under the conditions of a mass concentration of sulfuric acid of 150 g/L, a reverse extraction ratio of 6:1, and an equilibrium time of 15 min, the mass concentration of vanadium in the reverse extraction solution was 18 630 mg/L, the multistage reverse extraction rate of vanadium was 99.5%, and the mass concentration of iron in the reverse extraction solution was only 70 mg/L. The effective enrichment and recovery of vanadium was realized. Vanadium and iron could be separated effectively and vanadium could be enriched and recovered from sulfuric acid leaching solution of FCC waste catalyst by controlling equilibrium time of extraction method.

Key words: catalytic cracking, waste catalyst, 2-ethylhexylphosphoric acid mono-2-ethylhexyl ester, extration, vanadium, iron