Aluminum cell having aluminum wettable cathode surface
First Claim
1. In a cell for the electrolytic reduction of alumina to aluminum, said cell comprising a receptacle, at least one anodic surface, a cathodic surface, means for providing electrical power, means for the introduction of bath materials and alumina, and means for the removal of product aluminum, the improvement wherein said cathodic surface comprises a Refractory Hard Material in a carbonaceous matrix comprising carbonaceous filler having a particle size less than about 100 mesh and carbonaceous additive having a particle size greater than about 100 mesh, bonded by non-graphitized amorphous carbon, said matrix having a rate of ablation essentially equal to the rate of wear and dissolution of said Refractory Hard Material in the operating environment of said cell.
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Accused Products
Abstract
Aluminum cells may be produced having cathode surfaces which are wetted by aluminum, said surfaces comprising Refractory Hard Materials in a non-graphitized carbon matrix. Such cells may utilize inclined or drained cathodes as well as non-consumable anodes.
30 Citations
18 Claims
- 1. In a cell for the electrolytic reduction of alumina to aluminum, said cell comprising a receptacle, at least one anodic surface, a cathodic surface, means for providing electrical power, means for the introduction of bath materials and alumina, and means for the removal of product aluminum, the improvement wherein said cathodic surface comprises a Refractory Hard Material in a carbonaceous matrix comprising carbonaceous filler having a particle size less than about 100 mesh and carbonaceous additive having a particle size greater than about 100 mesh, bonded by non-graphitized amorphous carbon, said matrix having a rate of ablation essentially equal to the rate of wear and dissolution of said Refractory Hard Material in the operating environment of said cell.
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5. In a cell for the electrolytic reduction of alumina to aluminum, said cell having a cathode comprising a cathode substrate and an aluminum wettable surface layer bonded thereto, the improvement wherein said surface layer comprises a coating composition consisting of Refractory Hard Material, thermosetting resinous binder, mix liquid, carbonaceous filler and carbonaceous additive, which coating after curing and carbonization comprises a Refractory Hard Material in a non-graphitized carbon matrix and exhibits an expansion between 800°
- C. and 1000°
C. of less than 0.2 percent, said matrix having a rate of ablation essentially equal to the combined rate of wear and dissolution of said Refractory Hard Material in the operating environment of said cell. - View Dependent Claims (6, 7, 8, 9, 10, 11, 12, 13)
- C. and 1000°
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14. An aluminum reduction cell having cathode and anode surfaces inclined from the horizontal, wherein said cathode surface comprises Refractory Hard Material in a non-graphitized carbon matrix exhibiting a rate of ablation such that said carbon matrix and said Refractory Hard Material are removed at essentially the same rate, said cathode surface consisting of an aluminum wettable cured and carbonized coating composition comprising titanium diboride refractory hard material, a thermosetting resinous binder system exhibiting a char yield greater than 50 percent, carbonaceous filler, and carbonaceous additive, said coating composition exhibiting a percentage of expansion between 800°
- C. and 1000°
C. less than 0.2 different from the percentage of expansion exhibited by the cathode substrate to which said coating is applied. - View Dependent Claims (15, 16, 17, 18)
- C. and 1000°
Specification