The Recovery of Rare Earth Concentrate from Spent Cracking Catalyst

One of the wastes from oil refining industry - the spent cracking catalyst (SCC) - contains 1-2 % of rare earth elements (REE), which makes it a promising source for REE recovery. The optimal conditions for the recovery of lanthanum compounds from the fluorinated model mixture of aluminum and lanthanum oxides by leaching with a KOH solution were found: temperature 57 degrees C, concentration of a KOH solution 20 %, and a 1.9-fold excess of KOH with respect to stoichiometry. The concentrate containing 9.1 % La and 1.5 % Ce was recovered under the optimal conditions from the residue after sublimation of fluorinated SCC.