Granted Patent B2

US 8,211,278 · App. 12/845,540 · Granted Jul 3, 2012

Abstract

Claims (38)

1. An electrode for use in an aluminum electrolysis cell, the electrode comprising:

0.01 to 0.75 wt. % metal additives, wherein the metal additives are selected from the group consisting of Fe, Ni, Co, and W, and combinations thereof;

the balance being TiB 2 and unavoidable impurities, wherein the unavoidable impurities make up less than 2 wt. % of the electrode;

wherein the electrode has a density of at least about 85% of its theoretical density.

2. The electrode of claim 1 , wherein the electrode includes not greater than 0.65 wt. % metal additives.

3. The electrode of claim 1 , wherein the electrode includes not greater than 0.50 wt. % metal additives.

4. The electrode of claim 3 , wherein the electrode includes at least about 0.05 wt. % metal additives.

5. The electrode of claim 4 , wherein the metal additive is selected from the group consisting of Fe, Ni and Co.

6. The electrode of claim 5 , wherein the metal additive is Fe.

7. The electrode of claim 5 , wherein the metal additive is Ni.

8. The electrode of claim 5 , wherein the metal additive is Co.

9. The electrode of claim 1 , comprising:

0.01 to 0.14 wt. % Fe;

0.01 to 0.14 wt. % Ni;

0.01 to 0.14 wt. % Co; and

0.01 to 0.45 wt. % W.

10. The electrode of claim 9 , comprising not greater than 0.10 wt. % each of Fe, Ni, and Co.

11. The electrode of claim 9 , comprising not greater than 0.07 wt. % each of Fe, Ni, and Co.

12. The electrode of claim 9 , comprising not greater than 0.05 wt. % each of Fe, Ni, and Co.

13. The electrode of claim 10 , comprising not greater than 0.30 wt. % W.

14. The electrode of claims 12 , comprising not greater than 0.20 wt. % W.

15. An aluminum electrolysis cell comprising the electrode of claim 1 .

16. A method comprising:

(a) producing a blended TiB 2 composition, the producing step comprising:

(i) selecting a metal additive selected from the group consisting of Fe, Ni, and Co, and combinations thereof;

(ii) selecting a density of an electrode to be produced;

(iii) selecting an amount of the metal additive to achieve the selected density; and

(iv) blending the selected amount of metal additive with a TiB 2 powder to produce a blended powder composition;

(b) producing an electrode from the blended TiB 2 composition, wherein the electrode realizes an actual density that is substantially similar to the selected density.

17. The method of claim 16 , wherein the selected density is in the range of from about 4.068 g/cc to about 4.430 g/cc, and wherein the amount of selected metal additive is in the range of 0.01 to 0.75 wt. %.

18. The method of claim 16 , comprising:

using the electrode as one of a cathode and an anode in an aluminum electrolysis cell, wherein the using comprises:

passing electricity through the electrode while the electrode is in communication with a molten salt bath of the aluminum electrolysis cell; and

in response to the passing step, reducing Al 2 O 3 of the molten salt bath to aluminum metal.

19. The method of claim 18 , wherein, during the using step, the electrode remains whole and absent of delamination and cracking for at least 120 days of continuous use.

20. A composition consisting essentially of TiB 2 and metal additives, wherein the composition includes 0.01 to 0.75 wt. % metal additives, the balance being the TiB 2 and unavoidable impurities, wherein the unavoidable impurities make up less than 2 wt. % of the electrode;

wherein the metal additives are selected from the group consisting of Fe, Ni, Co, and W, and combinations thereof; and

wherein the electrode has a density of from about 85% to about 99% of its theoretical density.

Assignments (6)