Patents Assigned to Societe Des Electrodes
  • Patent number: 4787965
    Abstract: The invention concerns a coating for providing protection from corrosion and oxidation in the hot state, which coating is intended for the carrier bars of prebaked anodes and the emergent, or exposed, carbonaceous part of said anodes for Hall-Heroult electrolysis tanks, which elements are formed of a composition of carbonaceous aggregate selected from coke, graphite, semi-graphite and electrode scrap, together with calcium aluminate cement having an alumina content which is at least equal to 70% and a total amount of troublesome impurities (SiO.sub.2, Fe.sub.2 O.sub.3, TiO.sub.2, K.sub.2 O, Cr.sub.2 O.sub.3 and Mn.sub.2 O.sub.3) of less than 5% and preferably less than 2%. The protective coating may further comprise an addition of alumina powder in a proportion which can be up to 50% of the weight of the aggregate and an addition of 0.01% to 5% of metal powder such as passivated aluminium powder of a grain size of less than 0.1 mm. The coating may be used in the form of paste or be applied by spray gun.
    Type: Grant
    Filed: November 6, 1987
    Date of Patent: November 29, 1988
    Assignees: Societe Des Electrodes, Refractaires Savoie (SERS)
    Inventors: Gabriel Audras, Bernard Samanos