Diffusion welded nonconsumable electrode assembly and use thereof for electrolytic production of metals and silicon

• US 4,468,298 A
• Filed: 12/20/1982
• Issued: 08/28/1984
• Est. Priority Date: 12/20/1982
• Status: Expired due to Fees

• Current Assignee: Aluminum Company of Egypt
• Original Assignee: Aluminum Company of Egypt
• Inventors: Vasudevan, Asuri K., Byrne, Stephen C.
• Primary Examiner(s): Williams, Howard S.
• Application Number:
  US06/451,070
• Time in Patent Office: 617 Days
• Field of Search: 204/60, 204/64 R, 204/64 T, 204/66, 204/67, 204/70, 204/286, 204/243 R, 204/290 R, 204/290 F, 204/291, 204/292
• US Class Current: 205/369
• CPC Class Codes: C25C 3/12 Anodes
• CPC Class Codes: C25C 7/025 used in cells for the electrolysis of melts

Abstract

A nonconsumable electrode assembly suitable for use in the production of metal by electrolytic reduction of a metal compound dissolved in a molten salt, the assembly comprising a metal conductor diffusion welded to a portion of a ceramic electrode body having a level of free metal or metal alloy sufficient to effect a metal bond.

Claims

1. A nonconsumable electrode assembly for use in the production of an element selected from the group consisting of aluminum, lead, magnesium, zinc, zirconium, titanium and silicon by electrolytic reduction of a compound comprised of such element dissolved in a molten halide salt, the assembly comprising:

a metal conductor for conveying electrical energy;

a ceramic electrode body having free metal or metal alloy in at least an outer surface portion thereof for making a connection between said metal conductor and said ceramic body; and

a diffusion welded connection between said metal conductor and said portion of said ceramic electrode body, said connection formed by a diffusion of metal particles between a portion of said metal conductor and said portion of said ceramic body.

2. The assembly in accordance with claim 1 wherein said outer surface portion is a chemically reduced portion of said ceramic electrode body.

3. The assembly in accordance with claim 1 wherein said free metal or metal alloy is selected from the group consisting of Fe, Ni, Al, Mg, Ca, Co, Sn, Ti, Cr, Mn, Zr, Cu, Nb, Ta, Li, Y, Pt, Pd and Ir.

4. The assembly in accordance with claim 1 wherein said ceramic electrode body includes at least one metal oxide.

5. The assembly in accordance with claim 4 wherein said outer surface portion is a chemically reduced portion of said ceramic electrode body.

6. The assembly in accordance with claim 1 wherein said ceramic electrode body includes at least one metal compound comprised of at least two metal oxides.

7. The assembly in accordance with claim 6 wherein said outer surface portion is a chemically reduced portion of said ceramic electrode body.

8. A process for producing an element selected from the group consisting of aluminum, lead, magnesium, zinc, zirconium, titanium and silicon by electrolytic reduction of a compound comprised of such element dissolved in a molten salt, said process including providing a nonconsumable anode assembly by the steps of:

providing a metal conductor for conveying electrical energy;

providing a ceramic electrode body having free metal or metal alloy in at least an outer surface portion thereof for making a connection between said metal conductor and said ceramic body; and

connecting said ceramic body to said metal conductor by diffusion welding a portion of said metal conductor and the portion of said ceramic body having the free metal or metal alloy therein, and thereby forming a metal bond between said ceramic body and said metal conductor.

9. A process in accordance with claim 8 wherein said free metal or metal alloy is provided by chemically reducing said outer surface portion of said ceramic body.

10. A process in accordance with claim 8 wherein said free metal or metal alloy is selected from the group consisting of Fe, Ni, Al, Mg, Ca, Co, Sn, Ti, Cr, Mn, Zr, Cu, Nb, Ta, Li, Y, Pt, Pd and Ir.

11. A process in accordance with claim 8 wherein said ceramic electrode body includes at least one metal oxide.

12. A process in accordance with claim 11 wherein said outer surface portion is a chemically reduced portion of said ceramic electrode body.

13. A process in accordance with claim 8 wherein said ceramic electrode body includes at least one metal compound comprised of at least two metal oxides.

14. A process in accordance with claim 13 wherein said outer surface portion is a chemically reduced portion of said ceramic electrode body.