Extraction method for non-ferrous metals
AssigneeChemsep Corporation
InventorSteven Jon Anderson
Life of this patent
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Abstract
Non-ferrous metals are recovered from metal bearing ores or other metal sources in substantially quantitative yields by treating a finely divided metal bearing material with an aqueous inorganic acid to form a slurry and baking the slurry at atmospheric pressure and at a temperature of about 350.degree. to 800.degree.C. or higher under quiescent conditions for a period of time sufficient to convert the non-ferrous metals into soluble salts. The fumes from the baking process are scrubbed with a dilute acid solution to extract volatile metal salts. The residue is leached with an appropriate solution or solutions to recover the soluble metal salts which are then recovered from the solution by conventional techniques.
Claims36
A process for treating mineral deposits to convert the non-ferrous metals contained therein to a recoverable form which comprises
- a. mixing a finely divided mineral deposit with an aqueous solution of an inorganic acid to form a slurry wherein the stoichiometric ratio of inorganic acid to non-ferrous metal is at least 1.5 to 1,
- b. heating said slurry to dryness and baking under quiescent conditions at a temperature of about 350.degree. C. to 800.degree. C. and for a period of time sufficient to convert said non-ferrous metals into recoverable metal salts.
A process for the recovery of non-ferrous metals from mineral deposits comprising the steps of
- a. mixing a finely divided mineral deposit with an aqueous solution of an inorganic acid to form a slurry wherein the stoichiometric ratio or inorganic acid to non-ferrous metal is at least 1.5 to 1,
- b. heating said slurry to dryness under quiescent conditions at a temperature of about 350.degree. C. to 800.degree. C. and for a period of time sufficient to convert said non-ferrous metals into recoverable metal salts,
- c. scrubbing the fumes or gases emanating from heating said slurry with an aqueous solution to remove volatilized non-ferrous metals removed during the heating process,
- d. treating the dried residue obtained from said heating process with one or more aqueous leach solutions to extract from said residue the soluble non-ferrous salts formed during the heating process, and
- e. recovering said non-ferrous metals from said scrubber and leach solutions.
A process for the recovery of precious metals selected from the group consisting of gold, silver and platinum from mineral deposits comprising the steps of
- a. mixing a finely divided mineral deposit with an aqueous solution of an inorganic acid to form a slurry wherein the stoichiometric ratio of inorganic acid to precious metal is at least 10 to 1,
- b. heating said slurry to dryness under quiescent conditions at a temperature of about 350.degree. to 800.degree. C. for a period of time sufficient to cause said precious metals to be released from whatever form they are in in the mineral deposit and be converted to recoverable metal salts,
- c. scrubbing the fumes or gases emanating from heating said slurry with an aqueous solution to remove volatilized precious metals removed during the heating process,
- d. treating the dried residue obtained from said heating process with one or more aqueous leach solutions to extract from said residue the soluble precious metals salt formed during the heating process, and
- e. recovering said precious metal from said scrubber and leach solutions.
Dependencies are inferred from the claim text.