Foundry sand with oxidation promoter
AssigneeGeneral Motors Corporation
InventorsNicholas Edward Sargent, June-Sang Siak, Mei Cai
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Abstract
Coating foundry sand with a thin layer of an oxidation-promoting catalyst. Preferred catalysts comprise ferric and cupric oxides. The catalysts promote the oxidation of any polymeric binder or residues admixed with the sand. The sand is coated by wetting the grains with a solution of a catalyst precursor, drying the sand and baking the sand in air to convert the precursor to the catalyst.
Claims6
Method of preparing reusable foundry sand comprising the steps of (a) coating grains of said sand with a solution of a precursor of an oxidation-promoting catalyst selected from the group consisting of ferric oxide and cupric oxide, (b) drying said sand to deposit said precursor on said grains, and (c) heating said sand sufficiently to convert said precursor to an adherent layer of said catalyst on said grains, said adherent layer serving to promote thermal oxidation of oxidizable polymers mixed with said sand.
Dependencies are inferred from the claim text.