Abstract:Cerium and lanthanum were extracted from spent automobile catalyst by sulfating roasting-acid leaching. The effects of sulfuric acid consumption, roasting temperature and time, leaching temperature, acid concentration and leaching time on leaching rates of cerium and lanthanum were investigated. The results show that the leaching rate of cerium and lanthanum is 85.80% and 85.01% respectively under the optimum conditions including ratio of acid to material of 0.9, roasting temperature of 150 ℃, roasting time of 3 h, leaching ratio of liquid to solid of 4∶1, acid concentration of 1.0 mol/L, leaching temperature of 60℃, and leaching time of 4 h.