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

• US 5,520,792 A
• Filed: 03/30/1995
• Issued: 05/28/1996
• Est. Priority Date: 04/19/1993
• Status: Expired due to Term

• Current Assignee: Nikko Materials USA, Inc. (Eternal Materials Co., Ltd.)
• Original Assignee: Electrocopper Products Limited
• Inventors: Peckham, Peter, Burgess, David P., Kohut, Stephen J., Haines, Ronald K., Gort, Wendy M., Jenkins, Jackson G.
• Primary Examiner(s): Niebling, John
• Assistant Examiner(s): Mee, Brendan
• Application Number:
  US08/454,537
• Time in Patent Office: 425 Days
• Field of Search: 204/106, 204/108, 205/74, 205/574, 205/575, 205/580, 205/583, 205/585
• US Class Current: 205/74
• CPC Class Codes: C22B 15/0067 with acids or salts thereof
• CPC Class Codes: C25C 1/12 of copper
• CPC Class Codes: C25C 5/02 from solutions
• CPC Class Codes: C25D 1/04 Wires; Strips; Foils
• CPC Class Codes: Y02P 10/20 Recycling

Abstract

This invention is directed to a process for making copper metal powder from copper-bearing material, comprising: (A) contacting said copper-beating 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 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 copper metal powder is converted 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.

Claims

1. A process for making copper metal powder from a copper-bearing material, said process including sequential steps (A), (B-1), (C-1), (B-2), (C-2), (E), (F) and (G), 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-1) contacting said copper-rich aqueous leaching solution with an effective amount of at least one copper-bearing water-insoluble extractant from step (C-2) to transfer copper ions from said copper-rich aqueous leaching solution to said copper-bearing extractant to form a copper-rich extractant and a first 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-1) separating said copper-rich extractant from said first copper-depleted aqueous leaching solution, advancing said copper-rich extractant to step (D);

(B-2) contacting said first copper-depleted aqueous leaching solution from step (C-1) with an effective amount of at least one copper-depleted extractant from step (E) to transfer copper ions from said first copper-depleted aqueous leaching solution to said copper-depleted extractant to form a copper-bearing extractant and a second copper-depleted aqueous leaching solution;

(C-2) separating said copper-bearing extractant from said second copper-depleted aqueous leaching solution, recirculating said copper-bearing extractant to step (B-1);

(D) contacting said copper-rich extractant from step (C-1) with an effective amount of at least one aqueous stripping solution to transfer copper ions from said copper-rich extractant to said stripping solution to form a first electrolyte solution and a copper-depleted extractant;

(E) separating said first electrolyte solution from said copper-depleted extractant, recirculating said copper-depleted extractant to step (B-2);

(F) advancing said first electrolyte solution to an electrolytic cell equipped with at least one first insoluble anode and at least one first cathode, adding benzotriazole to said first electrolyte solution, and applying an effective amount of voltage across said first anode and said first cathode to deposit copper powder on said first cathode, the amount of benzotriazole added being sufficient to produce as plated copper powder having an apparent density in the range of about 1 to about 4 g/cm³, said first electrolyte solution containing organic impurities carried over from one or more of said contacting steps; and

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

2. A process for making copper metal powder from a copper-bearing material, 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 being selected from the group consisting of betadiketone and 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, adding benzotriazole to said first electrolyte, and applying an effective amount of voltage across said first anode and said first cathode to deposit copper metal powder on said first cathode, the amount of benzotriazole added being sufficient to produce as plated copper powder having an apparent density in the range of about 1 to about 4 g/cm³, said first electrolyte solution containing organic impurities carried over from one or more of said contacting steps; and

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

3. A process for making copper metal powder from a copper-bearing material, 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, adding benzotriazole to said first electrolyte, and applying an effective amount of voltage across said first anode and said first cathode to deposit copper metal powder on said first cathode, the amount of benzotriazole added being sufficient to produce as plated copper powder having an apparent density in the range of about 1 to about 4 g/cm³, said first electrolyte solution containing organic impurities carried over from one or more of said contacting steps; and

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

4. The process of claim 3 with the step of separating said copper-rich aqueous solution formed in step (A) from said copper-beating material.

5. The process of claim 3 wherein said aqueous leaching solution comprises sulfuric acid or ammonia.

6. The process of claim 3 wherein said extractant in step (B) comprises at least one compound represented by the formula ##STR6## wherein R¹, R², R³, R⁴, R⁵, R⁶ and R⁷ are independently hydrogen or hydrocarbyl groups.

7. The process of claim 3 wherein said extractant in step (B) comprises at least one compound represented by the formula ##STR7## wherein R¹ and R² are independently hydrogen or hydrocarbyl groups.

8. The process of claim 3 wherein said extractant in step (B) comprises at least one compound represented by the formula ##STR8## wherein R¹ and R² are independently alkyl groups or aryl groups.

9. The process of claim 3 wherein said ion exchange resin is a copolymer of styrene and divinylbenzene characterized by the presence of at least one functional group selected from -SO₃^-, --COO^-, ##STR9##

10. The process of claim 3 wherein said first electrolyte solution formed in step (E) has a copper ion concentration in the range of about 2 to about 60 grams per liter and a free sulfuric acid concentration in the range of about 70 to about 290 grams per liter.