Method of making refractory hard metal containing tiles for aluminum cell cathodes
First Claim
1. A method for preparing an aluminum-wettable cathode surface, which method comprises:
- (a) preparing a molding composition of Refractory Hard Material, carbonaceous filler having a particle size less than 100 mesh, and a thermosetting resinous binder system having a char yield greater than 25 percent;
(b) hot-pressing said composition to the surface of a cathode block to form a cured, adherent surface layer thereupon; and
(c) carbonizing said surface layer to a carbonaceous matrix containing Refractory Hard Material, bonded by amorphous carbon.
4 Assignments
0 Petitions
Accused Products
Abstract
This invention relates to electrolytic reduction cells for aluminum production wherein tiles have been placed upon the cathode surfaces to improve the cell operation. These tiles have aluminum-wettable surfaces, which reduce electrical losses and increase cathode life. The tiles are produced from a mixture of refractory hard metal (RHM), a thermosetting resin, carbonaceous fillers and carbonaceous additives. The tiles are physically formed, polymerized and/or cross linked, and carbonized to form a tile which can be inserted into a cell. The tile may have the RHM homogeneously dispersed throughout the tile structure, or it may have the RHM concentrated in layered form.
21 Citations
25 Claims
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1. A method for preparing an aluminum-wettable cathode surface, which method comprises:
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(a) preparing a molding composition of Refractory Hard Material, carbonaceous filler having a particle size less than 100 mesh, and a thermosetting resinous binder system having a char yield greater than 25 percent; (b) hot-pressing said composition to the surface of a cathode block to form a cured, adherent surface layer thereupon; and (c) carbonizing said surface layer to a carbonaceous matrix containing Refractory Hard Material, bonded by amorphous carbon. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method for forming an aluminum-wettable cathode surface, which method comprises:
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(a) preparing a molding composition of Refractory Hard Material, carbonaceous filler having a particle size less than 100 mesh, and a thermosetting resinous binder system having a char yield greater than 25 percent; (b) hot pressing said composition to form a cured, rigid element comprising Refractory Hard Material in a carbonaceous matrix; (c) further heating said element to fully carbonize said matrix without graphitizing the carbon present in the binder system; and (d) adhering the thus carbonized element to a carbon cathode block. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16)
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17. A method for forming an aluminum-wettable cathode surface, which method comprises:
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(a) preparing a molding composition of Refractory Hard Material, carbonaceous filler having a particle size less than 100 mesh, and a thermosetting resinous binder system having a char yield greater than 25 percent; (b) hot pressing said composition to form a cured, rigid element comprising Refractory Hard Material in a carbonaceous matrix; (c) adhering said rigid element to a carbon cathode block; and (d) carbonizing said element in situ to form a carbon block having a surface layer comprising Refractory Hard Material in a carbonaceous matrix bonded by amorphous carbon.
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18. A method for preparing an aluminum-wettable cathode surface, which method comprises:
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(a) preparing a molding composition of Refractory Hard Material, carbonaceous filler, and a thermosetting resinous binder system having a char yield greater than 25 percent; (b) preparing a carbon mixture of carbonaceous filler and thermosetting resinous binder system; (c) hot-pressing and carbonizing a layered structure of said molding composition and said carbon mixture to form a unitary layered element of Refractory Hard Material in a carbonaceous matrix, and carbon; and (d) adhering said element to a carbon cathode block with said Refractory Hard Material containing carbonaceous matrix exposed. - View Dependent Claims (19, 20, 21, 22, 23, 24, 25)
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Specification