Recovery of platinum group metals
AssigneeSouth Dakota School of Mines and Technology
InventorsKenneth N. Han, Peter Nam-soo Kim
Life of this patent
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Abstract
This invention relates to the recovery of platinum group metals and, more particularly, to the recovery of platinum group metals from various sources by roasting the source material with one or more of sulfuric acid, a sulfate and/or a bi-sulfate and with one or more halogen salt. The roasted product is put in contact with a leaching solution to dissolve at least a portion of the platinum group metals, which then may be separated and recovered.
Claims24
A method of recovering a platinum group metal from a source material, comprising the steps of:
- a) mixing a source material comprising a platinum group metal with at least one selected from the group consisting of sulfuric acid, a sulfate and a bi-sulfate, and with at least one halogen salt to form a roasting mixture;
- b) heating the roasting mixture to a temperature in the range of approximately 450° C. to approximately 700° C. to form a roasted product;
- c) contacting the roasted product with a leaching solution to dissolve at least a portion of the platinum group metal into the leaching solution;
- and
- d) recovering at least a portion of the platinum group metal from the leaching solution.
A method of separating a platinum group metal from a source material, comprising the steps of:
- a) combining a source material comprising at least one platinum group metal with a solution comprising water, at least one halogen salt, and at least one selected from the group consisting of sulfuric acid, a sulfate and a bi-sulfate to form a roasting mixture;
- b) heating the roasting mixture to a temperature of approximately 450° C. to approximately 700° C. to form a roasted product;
- c) contacting the roasted product with a leaching solution having a pH of approximately 0.5 to approximately 7;
- and
- d) separating at least a portion of the platinum group metal from the leaching solution.
A method of recovering platinum group metals from a catalyst matrix, comprising the steps of:
- a) crushing a catalyst matrix containing at least one platinum group metal;
- b) mixing the crushed catalyst matrix with one or more selected from the group consisting of sulfuric acid, a sulfate and a bi-sulfate, with at least one halogen salt and with water to form a roasting mixture;
- c) roasting the roasting mixture at a temperature of approximately 450° C. to approximately 700° C. to form a roasted product;
- d)contacting the roasted product with an acidic leaching solution;
- e)separating the non-dissolved solids from the leaching solution;
- and
- f) recovering at least a portion of the platinum group metal from the leaching solution.
Dependencies are inferred from the claim text.