Cover for an electrolysis cell for procuding aluminium

Abstract

The invention relates to non-ferrous metallurgy, more particularly to producing aluminium by electrolysis, and even more particularly to a structural element for covering the space above a melt in an electrolysis cell for producing aluminium by the electrolysis of cryolite-alumina melts. In a cover for an electrolysis cell for producing aluminium, which is in contact with a vapour-gas phase when the electrolysis cell is in operation and which is in the form of central and peripheral sections which are movably arranged relative to each other, the central and peripheral sections are made from a corrosion-resistant and erosion-resistant material which comprises 80.0-99.0 wt % of fluorophlogopite and 20.0-1.0 wt % of a refractory filler. The central sections of the cover may be permanently fixed on each anode rod, and the peripheral sections may be configured as convex panels rigidly and removably fixed on the top surface of a cathode and supported by the central section of the cover. Moreover, the refractory filler may be chosen from the following chemical substances: clay, calcium fluoride, rutile, sodium aluminosilicate, fluorapophyllite, nepheline, olivine, magnesium fluoride, and spinel. The end and side joints of the central and peripheral covers may be coated with a sealant layer in the form of a layer of alumina, and the central section of the cover may be provided with apertures. The use of this invention provides for the hermetic sealing of the cover, the reliability and safety of the structure, and a reduction in energy consumption.

1 . A cover for an electrolysis cell for producing aluminium, which is in contact with a vapour-gas phase when the electrolysis cell is in operation and which is in the form of central and peripheral sections which are movably arranged relative to each other, characterized in that the central and peripheral sections are made from a corrosion-resistant and erosion-resistant material which comprises 80.0-99.0 wt % of fluorophlogopite and 20.0-1.0 wt % of a refractory filler. 
     
     
         2 . The cover according to  claim 1 , characterized in that central sections of the cover are permanently fixed on each anode rod. 
     
     
         3 . The cover according to  claim 1 , characterized in that peripheral sections are configured as convex panels rigidly and removably fixed on the top surface of a cathode and supported by the central section of the cover. 
     
     
         4 . The cover according to  claim 1 , characterized in that the refractory filler may be chosen from the following chemical substances: clay, calcium fluoride, rutile, sodium aluminosilicate, fluorapophyllite, nepheline, olivine, magnesium fluoride, and spinel. 
     
     
         5 . The cover according to  claim 1 , characterized in that the end and side joints of the central and peripheral covers are coated with a sealant layer in the form of a layer of alumina. 
     
     
         6 . The cover according to  claim 1 , characterized in that the central section of the cover is provided with apertures.