The invention discloses a method for extracting
tungsten,
titanium and
vanadium from a waste SCR (
selective catalytic reduction) catalyst, which comprises the following steps: crushing the waste SCR catalyst, adding a strongly alkaline solution, and reacting; filtering, separating, then adding strong acid into the
sodium tungstate and
sodium vanadate mixed solution, and reacting to obtain
tungstic acid and a
sodium salt and vanadic acid
mixed solution; regulating the pH value of the
sodium salt and vanadic acid
mixed solution until precipitate is separated out, thus obtaining
ammonium vanadate; then adding
sulfuric acid into the
tungsten-and-
vanadium-removed SCR catalyst, and reacting to obtain a titanyl
sulfate solution and solids such as aluminum
slag and the like; then adding water into the titanyl
sulfate solution, and hydrolyzing to obtain
titanic acid and a waste acid solution; and finally, respectively calcining the obtained
ammonium vanadate,
tungstic acid and
titanic acid to obtain
vanadium pentoxide,
tungsten trioxide and
titanium dioxide. According to the invention, tungsten,
titanium and vanadium can be extracted from the SCR catalyst through the reaction with strong alkali and strong acid at a low temperature, the
equipment requirement is low, the
energy consumption is low, some products having added values can be coproduced, and no secondary
pollution is generated, thereby facilitating popularization and application.