Hydrometallurgical process for recovering precious metals from anode slime
US4293332A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 20, 1980 |
| Grant date | Oct 6, 1981 |
| Priority date | — |
| Expiry date | Mar 20, 2000 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P10/20
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A hydrometallurgical process for recovering precious metals, such as gold, silver, selenium, and tellurium etc. from anode slime has been developed and tested successfully. The process comprises three major unit operations: leaching, liquid-liquid extraction, and reduction. The decopperized anode slime is first leached with nitric acid at an elevated temperature to obtain a leach solution containing at least about 95% by weight of the silver content, 96% by weight of the selenium content and 76% by weight of the tellurium content of the decopperized anode slime. Silver in the nitric acid leach solution is recovered in the form of silver chloride. Subsequent to the recovery of silver chloride, the selenium, tellurium, copper and other impurities-containing solution is denitrated and chlorinated by a liquid-liquid extraction technique. This selenium, tellurium, copper and other impurities-containing chloride solution is treated to separate tellurium from selenium, copper and other impurities by a liquid-liquid extraction technique. Selenium and tellurium are then recovered individually by passing sulfur dioxide through the selenium-containing and tellurium-containing solutions. The n…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.