Process for recovering valuable metal from waste catalyst

A process for recovering Mo, V, Ni and Co valuable metals from a waste catalyst containing predominantly alumina and containing Mo, V, Ni and Co, comprising the steps of:

• (a) roasting the waste catalyst at a temperature of from 400.degree. C. to 1000.degree. C. to form a roasted product;
• (b) dissolving the roasted product with sulfuric acid in the presence of at least one added metal as dissolution catalyst selected from the group consisting of aluminum, nickel and cobalt to prepare a reducing solution;
• (c) separating and recovering aluminum from the reducing solution, while providing the reducing solution, from which aluminum has been separated, as a residual solution for extracting molybdenum there from;
• (d) extracting molybdenum from the residual solution of step (c) by contact with a solvent extractant selective to Mo and recovering extracted molybdenum, while providing the reducing solution, from which molybdenum was recovered, as a residual solution for extracting vanadium therefrom;
• (e) extracting vanadium from the residual solution of step (d) by contact with a solvent extractant selective to V and recovering extracted vanadium, while providing the reducing solution, from which vanadium has been recovered, as a residual solution for recovering nickel and cobalt therefrom;
• and
• (f) recovering nickel and cobalt from the residual solution of step (e).