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

  • US 5,458,746 A
  • Filed: 08/09/1994
  • Issued: 10/17/1995
  • Est. Priority Date: 04/19/1993
  • Status: Expired due to Term
First Claim
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1. A process for making copper foil from a copper-bearing material selected from the group consisting of copper ore, smelter flue dust, copper cement and copper-containing waste, said process comprising:

  • (A) contacting said copper-bearing material with an effective amount 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;

    said extractant comprising (i) at least one oxime characterized by a hydrocarbon linkage with at least one --OH group and at least one ═

    NOH group attached to different carbon atoms on said hydrocarbon linkage, (ii) at least one betadiketone, or (iii) at least one ion-exchange resin;

    (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 into an electrolytic cell equipped with at least one first insoluble 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, said first electrolyte solution containing impurities carried over from one or more of said contacting steps;

    (G) removing copper metal powder from said first cathode;

    (H) dissolving said copper powder from step (G) in an aqueous sulfuric acid solution to form a second electrolyte solution;

    (I) flowing said second electrolyte solution in an electroforming cell between a second anode and a second cathode, said second cathode being a rotating cathode, and applying an effective amount of voltage across said second anode and said second cathode to deposit copper foil on said second cathode, said second electrolyte solution being characterized by the addition of one or more of an active-sulfur containing material, a gelatin, molasses, guar gum, a polyalkylene glycol, dithiothreitol, an amino acid, acrylamide, sulfopropyl disulfide, tetraethylthiuram disulfide, benzyl chloride, epichlorohydrin, chlorohydroxylpropyl sulfonate, an alkylene oxide, a sulfonium alkane sulfonate, thiocarbamoyldisulfide, selenic acid, or a mixture of two or more thereof; and

    (J) removing said copper foil from said second cathode.

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