Method for reclaiming gold
US4668289A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 22, 1985 |
| Grant date | May 26, 1987 |
| Priority date | — |
| Expiry date | Nov 22, 2005 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P10/20
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A method for reclaiming gold in metallic form from gold-containing scrap, including gold-containing base metal alloys and articles in which base metals are at least partially covered with a layer of gold. The method includes the steps of exposing the gold-containing scrap under an inert atmosphere to a leaching solution. The leaching solution has dissolved therein an oxidizing agent including metal ions capable of assuming at least two oxidation states, a portion of the metal ions being in the higher of the two oxidation states. The leaching solution also contains a complexing agent including halide ions in aqueous solution. By so exposing the gold-containing scrap to the leaching solution, base metal contained therein is dissolved to leave a solid metallic residue enriched in gold. The solid metallic residue then is collected mechanically.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.