Extraction of Lanthanum Oxide from Different Spent Fluid Catalytic Cracking Catalysts by Nitric Acid Leaching and Cyanex 923 Solvent Extraction Methods

A laboratory-scale procedure was developed to obtain lanthanum oxide from spent fluid catalytic cracking catalyst, commonly used in the heavy crude oil process. Two different solids, consisting mainly of silica, alumina, and a certain amount rare earth elements, were leached under several conditions recover earths. Nitric acid leaching lead highest recovery lanthanum, reaching percentage greater than 95% when 1.5 M concentration used. Subsequently, liquid phases subjected liquid–liquid extraction process using Cyanex 923 diluted Solvesso 100, quantitatively extracted. Lanthanum also stripped oxalic corresponding oxalates, as revealed by X-ray diffraction (XRD), thermogravimetric analysis (TGA), differential thermal (DTA), Fourier transform infrared (FTIR) techniques. After treatment at 1200 °C for 2 h, these solids yielded oxide.