Acid leaching of lanthanum from spent cracking catalyst

Fundamental aspects were studied of the acid leaching of lanthanum from a spent cracking catalyst, a composite material constituted by an amorphous aluminosilicate matrix and a lanthanum-promoted zeolite. It was demonstrated that the degree of lanthanum leaching depends on the nature and concentration of the leaching agent, temperature, and process duration. It was found that the acid leaching of lanthanum is accompanied by dealuminization of the matrix and zeolite, which leads to activation of the sorption processes of the solid residue.