Abstract:The alkaline roasting-water leaching process was used to extract vanadium and tungsten from the waste SCR denitrification catalyst for the subsequent resource utilization of vanadium and tungsten. The effects of roasting temperature, roasting time, Na2CO3 ratio( Na2CO3 quality : waste catalyst quality ), water leaching temperature and water leaching time on the leaching effect of vanadium and tungsten were investigated. The roasting mechanism was explored by XRD analysis of roasting products. The experimental results show that the suitable alkaline roasting-water leaching conditions for the waste SCR denitrification catalyst are as follows: roasting temperature 875 ℃, roasting time 1.5 h, Na2CO3 ratio 1:1, water leaching temperature 80 ℃, water leaching time 2 h. Under these conditions, the leaching rates of vanadium and tungsten reach 91.33% and 96.34% respectively. According to the results of XRD analysis, vanadium and tungsten are converted to soluble NaV6O15 and Na2WO4 respectively during the alkaline roasting process. After alkaline roasting-water leaching treatment, more than 90 % of vanadium and tungsten entered the water leaching solution, while less than 2 % of titanium entered the water leaching solution.