Process for extracting metal values from ores
US5169503A · kind A · utility
Inventors
Key dates
| Filing date | Jun 24, 1988 |
| Grant date | Dec 8, 1992 |
| Priority date | — |
| Expiry date | Jun 24, 2008 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P10/20
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Metal values are solubilized from ore by a lixiviant having a pH from 5 to 8, comprising an aqueous solution of a chloride salt and a hypochlorite salt. Cyanuric acid may be added to retard decomposition of the lixiviant. In one alternative embodiment, any remaining hypochlorite ions are then eliminated by adding hydrogen peroxide or a reducing agent to the pregnant lixiviant. Metal values are recovered by reduction using carbon, electrowinning, or other conventional techniques. In an alternative embodiment for extraction of gold or silver, the steps are combined by using finely ground ore containing sulfides or carbonaceous material to both reduce any remaining hypochlorite ions and precipitate the metal values from the lixiviant. The lixiviant can then be regenerated either by electrolysis or addition of hypochlorite salt.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.