Abstract: A method for recycling metals from waste molybdic catalysts, comprises steps of leaching, by soaking a waste molybdic catalyst into a highly oxidized acid and conducting a reaction between sulfur in the waste molybdic catalyst and the acid to obtain sulfide and vaporizer, wherein metals in the waste molybdic catalyst are dissolved and oxidized by the acid to obtain a first solution and dregs; and refining, by further dissolving metals in the dregs into a second solution, and extracting metals in the waste molybdic catalyst from the first and second solution; wherein, the vaporizer obtained from the step of leaching is converted into highly oxidized acid and recycled in the step of leaching.

Abstract: A method for recycling metals from waste tungsten catalysts comprises steps of: leaching, by soaking a waste tungsten catalysts into a highly oxidized acid and conducting a reaction between sulfur of the waste tungsten catalysts and the acid to obtain sulfide and oxidized acidic groups, wherein metals in the waste tungsten catalysts are dissolved and oxidized by the acid to obtain a first solution and dregs; and refining, by extracting metals of the waste tungsten catalysts from the first solution; wherein, the oxidized acidic groups obtained from the step of leaching is converted into highly oxidized acid, which is capable of being recycled.