Protective coatings for the carrier bars of pre-baked anodes and the emerging part of the anodes

摘要

A coating composition is disclosed for protecting from corrosion and oxidation in the hot condition carrier bars of pre-baked anodes and the emergent carbonaceous part of the anodes for the protection of aluminum in the Hall-Heroult process. The composition consists essentially of dry matter formed by calcium alumnate cement having an alumina content of at least 70% and a low content of impurities, magnesium spinel, and optionally, further alumina, together with water in the amount of 10 to 80% by weight of the total dry matter.