Extraction of copper from copper sulfides

Abstract

Abstract Copper is recovered from its sulfidic ores by a process wherein the ore is mixed and fused with at least a stoichiometric amount of a sulfide of sodium or potassium which may be prepared in situ by reacting sulfur with potassium or sodium hydroxide. The mixture is heated under vacuum in the absence of water, oxygen and CO 2 to a temperature above the melting point of the selected potassium or sodium sulfide and maintained below the decomposition point of the sulfide for a time sufficient to cause the sodium or potassium sulfide to combine with the sulfur of the copper sulfide to form metallic copper and copper oxides and the higher (sulfur content), sulfides of sodium or potassium, the resulting melt is cooled and leached with cold water to remove the sodium or potassium polysulfides and leaving behind metallic copper and copper oxides. The polysulfides can be recovered and recycled. The preferred unsaturated sulfides are sodium trisulfide and potassium tetrasulfide. This process is applicable to various ore concentrates including bornite, chalcocite, chalcopyrite, covellite, enargite, stromerite, tennanite, and tetramedrite. Other metals present in the copper sulfide containing ores including atimony arsenic, zinc, lead, silver, molybdenum can be removed after isolating the copper and copper oxides.

Inventors

• 👤 Rollan Swanson

Bibliographic Details