Recovery of rare earth elements from spent fluid catalytic cracking catalyst using hydrogen peroxide as a reductant

Abstract A hydrochloric leaching process was applied to recover rare earth elements (REEs, mainly La and Ce) from spent fluid catalytic cracking (FCC) catalysts using H2O2. The Ce of CeO2 in FCC catalyst is firstly reduced to Ce3+ ions with H2O2, and then it is easily leached out by HCl acid. Followed by ion exchange extraction with octyl phosphate, precipitation with ethanedioic acid and calcination at high temperature, high recovery of REEs (93.0%) is achieved. The leached REEs were extracted with P507 in kerosene diluent extracting 94.5% of the REEs at 40 °C for 30 min at 1:1 distribution. Then, 98.1% of the loaded REEs was stripped under the conditions of 1.8 mol/L HCl at the temperature of 30 °C for 20 min. This reduction and leaching process provides a high efficiency method for valuable metal elements from spent catalyst.