Process for recovering metals from coal liquefaction residue containing spent catalysts

A method of recovering metals from a spent coal liquefaction catalyst, the method comprising:

• (a) withdrawing a coal liquefaction residue from a coal liquefaction process wherein the coal liquefaction residue contains a spent catalyst;
• (b) classifying the coal liquefaction residue to a particle size sufficient to pass a 200-mesh sieve to form a spent catalyst residue;
• (c) contacting the spent catalyst residue with a weak acid solution to dissolve alkaline earth metal compounds and form a first slurry containing the spent catalyst, ash, insoluble organic matter and dissolved alkaline earth metal complexes;
• (d) separating and removing the dissolved alkaline earth metal complexes from the slurry to form a metals bearing materials containing the spent catalyst;
• (e) leaching the metals bearing materials containing the spent catalyst with an ammonia solution in the presence of air, at a sufficient temperature and pressure to form a pressure leach slurry containing at least a Group VIB soluble metal complex. insoluble organic matter and ash;
• (f) separating and removing the metals bearing materials from the pressure leach slurry to form a pressure leach solution;
• (g) precipitating from the pressure leach solution at least a portion of the Group VIB metal, wherein the precipitation is carried out at a first pre-selected pH to precipitate as insoluble metal complexes at least a portion of the Group VIB metal.