Aluminum cell cathode coating method
AssigneeMartin Marietta Corporation
InventorsLarry G. Boxall, William M. Buchta, Arthur V. Cooke, Dennis C. Nagle, Douglas W. Townsend
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Abstract
This invention relates to a method for the application of a coating composition containing Refractory Hard Material to a cathode substrate to prepare an aluminum wettable cathode surface. A mixture of Refractory Hard Material and carbon system is applied to a cathode substrate, cured and carbonized to a non-graphitized carbon matrix containing Refractory Hard Material, characterized by strong bonding of said matrix to said substrate and an ablation rate of said carbon matrix similar to the combined rate of wear and dissolution of the Refractory Hard Material.
Claims23
A method for producing an aluminum wettable cathode surface for an aluminum reduction cell, which method comprises applying to a cathode substrate a coating composition comprised of Refractory Hard Material, a thermosetting binder comprising a single resin selected from the group consisting of phenolic, furane, polyphenylene, heterocyclic, epoxy, silicone, alkyd, and polyimide resins, a mix liquid, carbonaceous filler, and carbonaceous additive, curing said coating composition to produce a relatively hard, adherent surface layer, and carbonizing said layer to produce an adherent aluminum wettable surface layer consisting of Refractory Hard Material in a carbonaceous matrix bonded by amorphous carbon, said surface layer characterized by a percentage of expansion between 800.degree. C. and 1000.degree. C. which differs from the percentage of expansion of said cathode substrate by less than 0.2.
Dependencies are inferred from the claim text.