Cyclic leach-precipitation process for recovering copper values from bodies of ore material containing copper minerals

Abstract

Abstract As part of a cyclic, copper leaching-precipitation process, an aqueous solution containing reducing ions selected from the group consisting of sulfite ion and bisulfite ion is injected into a body of copper ore material at a location or locations adjacent the emergence from such body of an applied acidic leach solution containing ferric ions and pregnant with copper values, for reducing ferric ions in such leach solution to ferrous ions so consumption of metallic iron in the precipitation stage is minimized. The injection site or sites are removed from access of atmospheric air, and injection is carried out in the absence of oxygen to prevent auto-oxidation of the reducing agent. Such agent acts as a bacteriacide to eliminate anaerobic, hydrogenaseproducing strains of bacteria normally present, which bacteria would otherwise reduce sulfates and produce hydrogen sulfide to thereby effect precipitation of soluble copper into insoluble copper sulfide. Additionally, the reducing agent inhibits the action of autotrophic aerobic bacteria normally present in areas penetrated by atmospheric air and thereby minimizes oxidation of ferrous ions to ferric.

Inventors

• 👤 Henry Rush Spedden
• 👤 Emil Edward Malouf

Bibliographic Details