Method for providing a cathode lining barrier layer in an electrolysis cell and a material for same

A method for providing a cathode lining barrier layer in a Hall-Héroult electrolysis cell for production of aluminum,

• wherein the cell comprises an electrolytic bath having components of NaF, AlF3, and Na3AlF6 in addition to other components,
• wherein the cathode lining comprises a cathode panel of cathode blocks supported by at least one layer of a refractory material, and
• wherein
• during lining of the pot, a mixed material that comprises a mixture of mineral(s) and a chemical compound(s) that effectively lowers the melting temperature of the mineral(s) is arranged between the at least one layer of refractory material and the cathode blocks,
• wherein the mixture of mineral(s) comprises sodium feldspar and/or nepheline syenite, and
• wherein the chemical compound(s) comprise fluorides,
• where during start-up of the cell and as a certain temperature is achieved in the mixed material, and further before penetration of the bath, the mixed material forms a viscous liquid, and
• where the viscous liquid has high viscosity, and a density higher than that of the bath components eligible to penetrate the cathode blocks and forms a barrier that is effectively immiscible with the penetrating bath components.