Method for recovering precious metal
AssigneeHeraeus Deutschland GmbH & Co. KG
InventorMarco Stemmler
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Abstract
A method for recovering precious metal from an acidic aqueous solution containing dissolved precious metal and free chlorine, comprising the following successive steps: (1) combining a salt of a non-precious metal present in a low oxidation state as a solid or as an aqueous solution with the acidic aqueous solution to consume the free chlorine and form an acidic aqueous mixture, and (2) adding non-precious metal to the acidic aqueous mixture formed in step (1) to precipitate elementary precious metal.
Claims17
A method for recovering precious metal from an acidic aqueous solution containing dissolved precious metal and free chlorine, the method comprising the following successive steps:
- (1) providing an acidic aqueous solution containing precious metal and free chlorine;
- (2) combining a salt of a non-precious metal present in a low oxidation state as a solid or as an aqueous solution with the acidic aqueous solution to completely or substantially completely consume the free chlorine and form an acidic aqueous mixture, and
- (3) adding non-precious metal to the acidic aqueous mixture formed in step (2) to precipitate elementary precious metal, wherein
- the acidic aqueous solution is characterized by (i) a fraction of dissolved precious metal in the range of 100 to 500 mg/l, (ii) a pH in the range of −0.8 to +1 and (iii) a content of the free chlorine in the range of 0.1 to 1 g/l, and
- the dissolved precious metal comprises at least one precious metal selected from the group consisting of gold, platinum, palladium, rhodium, iridium, osmium and ruthenium.
A method for recovering precious metal from an acidic aqueous solution containing dissolved precious metal and free chlorine, the method comprising the following successive steps:
- (1) providing an acidic aqueous solution containing precious metal and free chlorine;
- (2) combining a salt of a non-precious metal present in a low oxidation state as a solid or as an aqueous solution with the acidic aqueous solution to completely or substantially completely consume the free chlorine and form an acidic aqueous mixture, and
- (3) adding non-precious metal to the acidic aqueous mixture formed in step (2) to precipitate elementary precious metal, wherein
- the acidic aqueous solution is characterized by (i) a fraction of dissolved precious metal in the range of 100 to 500 mg/l, (ii) a pH in the range of −0.8 to +1 and (iii) a content of free chlorine in the range of 1000 to 10,000 ppm by weight, and
- the dissolved precious metal comprises at least one precious metal selected from the group consisting of gold, platinum, palladium, rhodium, iridium, osmium and ruthenium.
Dependencies are inferred from the claim text.