Processes for recovering precious metals
US5238662A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 11, 1992 |
| Grant date | Aug 24, 1993 |
| Priority date | — |
| Expiry date | May 11, 2012 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P10/20
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Disclosed is a process for recovering precious metals using a combination of smelting and an effective utilization of molten salt chlorination. More specifically, disclosed is a process including the steps of (i) contacting, for example, a matte with a chloride salt containing at least one of potassium, cesium or rubidium, but not sodium or lithium to form a matte/salt solids mixture, (ii) introducing the solids mixture into a chloride melt having a temperature ranging from 300.degree. C. to 650.degree. C., said melt containing at least one of potassium, cesium, rubidium, sodium or lithium, (iii) introducing a chlorine containing gas into the melt, and (iv) maintaining the salt ratio in the matte/salt mixture at a stoichiometrically equivalent amount with the precious metals and base metals contained in the matte. Also disclosed is a selective dissolution technique which involves multiple dissolution stages wherein each stage the oxidation potential is maintained at a certain level and an alkali metal chloride is added such that platinum and palladium can be separately recovered.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.