The work is devoted to the actual problem of corrosion of the gas-collecting bell of the Soderberg electrolysis cell, which operates in close proximity to the molten electrolyte. Due to gas corrosion during the operation of the electrolysis cell, the cast-iron sections are destroyed and the release of anode gases into the atmosphere of the housing occurs. Iron-containing corrosion products falling into the melt of primary aluminum reduce its quality and grade. In order to prevent this phenomenon, the effectiveness of their protection with a dry mixture for obtaining a protective oxide-ceramic coating of cast-iron surfaces of gas-collecting bell is studied. The results obtained proved the effectiveness of the proposed coating: the service life of the gas-collecting bell sections increased by 4 times. After applying the protective coating for A85 grade aluminum, it increased from 2 to 24%, and the share of A7 grade aluminum decreased from 25 to 18 %.