Journal of Chemical Engineering of Japan, Vol.53, No.7, 351-358, 2020
Recovery of Rare Metals from Spent Denitrification Catalysts in Coal-Fired Power Plants
A process for selectively recovering titanium, vanadium, and tungsten from spent denitrification catalysts generated in coal-fired power plants was developed in this study. Carbon was added as a reducing agent and the chloride volatilization behavior of rare metals under a chlorine gas flow was subsequently tracked. This demonstrated that the chloride volatilization reaction is promoted by the addition of carbon. In addition, if the spent catalyst is heat-treated in methanol vapor to deposit solid carbon on the catalyst surface, the chloride volatilization promotion is particularly high. After carbon was added by this method, heating to 400 degrees C under a chlorine gas flow selectively released rare metals without releasing coexisting elements such as iron and aluminum. In addition, the released rare metals were converted into chlorides upon cooling and were completely recovered in solid or liquid form.