Abstract: Titanium was recovered from spent SCR catalyst by sodium roasting.The effects of sodium dosage,roasting temperature,roasting time,material particle size and sulfuric acid concentration on titanium leaching rate were studied.From the experimental results,the optimum roasting conditions were selected at the alkali dosage of 1.2 times of the theoretical value,the roasting temperature of 700 ℃,the roasting time of 3 h,and the material particle size of -150 μm.The roasting clinker after washing was leached by sulfuric acid with 45% mass concentration,resulting in more than 89% of the titanium leaching rate.Titanium dioxide was prepared by hydrolysis of the leaching solution,with the titanium precipitation rate and purity of titanium dioxide more than 93% and 93%,respectively.