Process for making copper metal powder, copper oxides and copper foil

Abstract

This invention is directed to a process for making copper metal powder from copper-bearing material, comprising: (A) contacting said copper-bearing material with an effective mount of at least one aqueous leaching solution to dissolve copper ions in said leaching solution and form a copper-rich aqueous leaching solution; (B) contacting said copper-rich aqueous leaching solution with an effective amount of at least one water-insoluble extractant to transfer copper ions from said copper-rich aqueous leaching solution to said extractant to form a copper-rich extractant and a copper-depleted aqueous leaching solution; (C) separating said copper-rich extractant from said copper-depleted aqueous leaching solution; (D) contacting said copper-rich extractant with an effective amount of at least one aqueous stripping solution to transfer copper ions from said extractant to said stripping solution to form a copper-rich stripping solution and a copper-depleted extractant; (E) separating said copper-rich stripping solution from said copper-depleted extractant to form a first electrolyte solution; (F) advancing said first electrolyte solution to an electrolytic cell equipped with at least one first anode and at least one first cathode, and applying an effective amount of voltage across said first anode and said first cathode to deposit copper metal powder on said first cathode; and (G) removing copper metal powder from said first cathode. In one embodiment the first electrolyte solution used in step (F) is characterized by a chloride ion concentration of up to about 5 ppm. In one embodiment the first electrolyte solution used in step (F) contains at least one triazole. In one embodiment the copper metal powder is convened to copper foil. In one embodiment the copper metal powder is converted to cuprous oxide, cupric oxide or a mixture thereof; these copper oxides can be readily dissolved in sulfuric acid and used to make copper foil.