Recovery of metal values from spent catalysts
AssigneeUnion Oil Company of California
InventorGeorge L. Tilley
Life of this patent
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Abstract
Spent catalysts from hydrocarbon refining processes, comprising transition metal compounds on aluminum oxide-containing supports, are subjected to an oxidative roasting and are treated with sulfuric acid in a counter-current digester to dissolve metals. Following operations to separate compounds of the various transition metals, a solution containing approximately stoichiometric equivalents of aluminum and sulfate is obtained.
Claims29
A method for the recovery of valuable components from a particulate catalyst material which contains compounds of metals on a support comprising aluminum oxide, which method comprises:
- (a) roasting the catalyst in the presence of oxygen;
- (b) reacting the roasted catalyst with sulfuric acid, in a single counter current digester, to produce a solution comprising aluminum and other metal ions;
- (c) separating other metals from aluminum;
- and
- (d) recovering a solution containing sulfate at approximately 1.5 times the molarity of aluminum.
A method for producing metal compounds from a particulate spent aluminum oxide-containing hydrocarbon refining catalyst, which comprises the steps of:
- (a) roasting the catalyst in an oxygen-containing atmosphere, at a temperature sufficient to substantially remove carbon from the catalyst;
- (b) reacting the roasted catalyst with sulfuric acid in a single counter-current digester to produce a solution having a pH above about 2;
- (c) separating other metal compounds from aluminum in the solution;
- and
- (d) recovering a solution which contains sulfate at approximately 1.5 times the molarity of aluminum.
A method for producing metal compounds from a particulate spent hydrocarbon refining catalyst comprising compounds of metals selected from the group consisting of molybdenum, cobalt, nickel, vanadium, or mixtures thereof, on a porous aluminum oxide support, which method comprises the steps of:
- (a) roasting the catalyst in an oxygen-containing atmosphere at a temperature between about 500.degree. C. and about 650.degree. C.;
- (b) reacting the roasted catalyst with sulfuric acid in a single counter-current digester to essentially completely dissolve the aluminum oxide and produce a solution having a pH between about 2.5 and about 3.2;
- (c) separating vanadium, if present, from the solution by extraction with a liquid extractant comprising an organophosphorus compound in a water-immiscible hydrocarbon solvent;
- (d) separating molybdenum, if present, from the solution by extraction with a liquid extractant comprising a tertiary amine in a water-immiscible hydrocarbon solvent;
- (e) separating cobalt and nickel, if present, from the solution by precipitating with a material selected from the group consisting of hydrogen sulfide, water soluble sulfides, water soluble poysulfides, and mixtures thereof,and removing formed precipitate;
- and
- (f) recovering a solution which contains sulfate at approximately 1.5 times the molarity of aluminum.
A method for the recovery of valuable components from a particulate catalyst material which contains compounds of metals on a support comprising aluminum oxide, which method comprises:
- (a) roasting the catalyst in the presence of oxygen;
- (b) feeding the roasted catalyst into the top of a single digester,
- (c) passing sulfuric acid into said digester from a point near the bottom of said digester,
- (d) reacting said roasted catalyst and said sulfuric acid to produce a solution comprising aluminum and other metal ions and a sludge,
- (e) establishing a liquid level in said digester by controlling the removal of said solution from said digester, at a point below the top of said digester,
- (f) removing said sludge from the bottom of said digester, and
- (g) recovering a solution having a very low undissolved solids content and containing sulfate at approximately 1.5 times the molarity of aluminum.
A method for the recovery of valuable components from a particulate catalyst material which contains compounds of metals on a support comprising aluminum oxide, which catalyst has been roasted in the presence of oxygen;
- which method comprises reacting said roasted catalyst and sulfuric acid to produce a solution comprising aluminum and other metal ions, by passing sulfuric acid into a single countercurrent digester, at a point near the bottom thereof, and allowing said sulfuric acid to rise through particles of said roasted catalyst;
- and recovering said solution containing sulfate at approximately 1.5 times the molarity of aluminum and having a very low undissolved solids content, by passing said solution through a filtration medium comprising a bed of larger particles of said roasted catalyst in the uppermost area of said digester.
Dependencies are inferred from the claim text.