Composition for making wettable cathode in aluminum smelting
Compositions for making wettable cathodes to be used in aluminum electrolysis cells are disclosed. The compositions generally include titanium diboride (TiB 2 ) and metal additives. The amount of selected metal additives may result in production of electrodes having a tailored density and/or porosity. The electrodes may be durable and used in aluminum electrolysis cells.
1. A component, comprising:
0.01 to not greater than 0.45 wt. % metal additives, the balance being TiB 2 and unavoidable impurities, wherein the unavoidable impurities make up less than 2 wt. % of the component;
wherein the metal additives at least include chromium (Cr), wherein the chromium content of the component is not greater than 0.35 wt. %;
wherein the component is crack-free and has a density of at least 90% to not greater than 98% of its theoretical density, and wherein the component has an apparent porosity of 0.05% to 4%.
2. The component of claim 1 , further wherein the component comprises a geometry selected from the group consisting of: a tube, a plate, a rod.
3. The component of claim 1 , wherein the component is configured as an electrode for use in an aluminum electrolysis cell.
4. The component of claim 1 , wherein the metal additives further include one or more of Fe, Ni, Co, and W.
5. The component of claim 1 , wherein the metal additives further include one or more of Mn, Mo, Pt, and Pd.
6. An electrode for use in an aluminum electrolysis cell, the electrode comprising:
0.01 to less than 0.5 wt. % metal additives, the balance being TiB 2 and unavoidable impurities, wherein the unavoidable impurities make up less than 2 wt. % of the electrode;
wherein the metal additives at least include chromium (Cr), wherein the chromium content of electrode is not greater than 0.35 wt. %;
wherein the electrode is crack-free and has a density of at least 90% to not greater than 98% of its theoretical density, and wherein the component has an apparent porosity of 0.05% to 4%.
7. The electrode of claim 6 , wherein the electrode is configured as a cathode in an aluminum electrolysis cell.
8. A method comprising:
(a) blending a first powder comprising TiB 2 with a second powder comprising a selected amount of metal additives to make a TiB 2 composition, the TiB 2 composition comprising:
from 0.01 to not greater than 0.45 wt. % of the metal additives, the balance being TiB 2 and unavoidable impurities, wherein the unavoidable impurities make up less than 2 wt. % of the electrode, wherein the metal additives at least include chromium (Cr), wherein the chromium content of electrode is not greater than 0.35 wt. %; and
(b) producing a TiB 2 component from the TiB 2 composition;
wherein the TiB 2 component is crack-free and has a density of at least 90% to not greater than 98% of its theoretical density, and wherein the component has an apparent porosity of 0.05% to 4%.
9. The method of claim 8 , wherein the producing step further comprises:
pressing the TiB 2 composition; and
sintering the pressed TiB 2 composition to yield the TiB 2 component.
10. The method of claim 8 , wherein the method comprises forming the TiB 2 component, the TiB 2 component comprising a geometry selected from the group consisting of: a plate, a rod, and a tube.
11. The method of claim 8 , wherein the producing step further comprises:
pressureless sintering the TiB 2 composition to yield the TiB 2 component.
12. The method of claim 8 , wherein the producing step further comprises:
sintering the TiB 2 composition at a temperature of between 1400° C. to 2100° C.
13. The method of claim 12 , wherein the producing step further comprises:
pressing the TiB 2 composition at a pressure from 70 kg/cm 3 to at least 350 kg/cm 3 .
14. The method of claim 8 , wherein the metal additives further include one or more of Mn, Mo, Pt, and Pd.
15. The method of claim 8 , wherein the metal additives further include one or more of Fe, Ni, Co, and W.
16. An electrode, comprising:
0.025 to 0.10 wt. % metal additives, wherein the metal additives at least include Cr;
the balance being TiB 2 and unavoidable impurities,
wherein the unavoidable impurities make up less than 2 wt. % of the component;
wherein the component has a density of 88.9% to 98.5% of its theoretical density, and
wherein the component has an apparent porosity of 0.05% to 4%.
17. The electrode of claim 16 , wherein the metal additives further include one or more of Mn, Mo, Pt, and Pd.
18. The electrode of claim 16 , wherein the metal additives further include one or more of Fe, Ni, Co, and W.