Patent ID: 7976688

Claim:
Method for manufacturing anodes used for the production of aluminum by fused bath electrolysis, the anodes comprising an anode stem made of a conducting metal and at least one anode block made of carbonaceous material, comprising the steps of: a) obtaining an anode stem; b) obtaining at least one anode block having an upper surface, and constructed and arranged to be fixed to the anode stem, the at least one anode block having never previously been inserted into an electrolytic cell; c) fixing one end of the anode stem onto the at least one anode block, so as to provide good mechanical attachment and good electrical connection between said stem and said at least one anode block; and d) before, during or after said fixing, and before placement of said anode in the electrolytic cell, depositing onto at least a portion of the upper surface of the at least one anode block, a protective layer of controlled thickness between 5 and 25 cm, the protective layer comprising a material resistant to temperature and corrosion by a medium above the electrolytic bath, and forming thereby a substantially solid protective coating comprising a solid annular zone peripherally around the upper surface of the at least one anode block.