Method for extracting valuable elements from waste SCR denitration catalyst

The invention discloses a method for extracting valuable elements from a waste SCR denitration catalyst. The method for extracting the valuable elements from the waste SCR denitration catalyst comprises the following steps: mixing catalyst powder and a sodium modifying agent, adding water, conducting uniform stirring and mixing, and then conducting pressing to form a blocky mixture; drying and dehydrating the blocky mixture in a low-temperature area, then roasting the blocky mixture at 700-800 DEG C, cooling the blocky mixture to 150-250 DEG C, mixing the blocky mixture and a second-stage dissolved-out solution, and conducting solid-liquid separation to obtain a first-stage dissolved-out solution and first-stage dissolved-out residues; mixing the first-stage dissolved-out residues and water, and conducting solid-liquid separation to obtain the second-stage dissolved-out solution and second-stage dissolved-out residues; introducing carbon dioxide into the first-stage dissolved-out solution until the pH value i