Patent · US Expired

Process for the extraction of precious metals from concentrates thereof

US4397689A · kind A · utility

8Cited by
7References
6Claims
0Family size

Assignee

Inventors

Key dates

Filing dateSep 1, 1981
Grant dateAug 9, 1983
Priority date
Expiry dateSep 1, 2001

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY02P10/20
  • WIPO fieldMaterials, metallurgy
  • WIPO sectorChemistry

Abstract

The process comprises the steps of leaching the concentrate with hot hydrochloric acid and chlorine gas to dissolve most of the gold, platinum and palladium, treating the residue from the leaching step with an excess of an alkaline oxidizing agent to solubilize the ruthenium, slurrying the resulting solids in water, combining the precious metal values from the slurry with the liquor from the leaching step and releaching the resulting slurry with hot hydrochloric acid and chlorine. The leach liquor which is then separated from the remaining solids is a chloride solution which contains substantially all the platinum group metals and gold present in the concentrate.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.