Effect of TiB2 Coating on Evolution of Cathode Lining during the Process of Primary Aluminum Production

A modified Rapoport apparatus for sodium expansion was used to determine the sodium expansion of TiB2-coated carbon cathode samples with different TiB2 contents. It was shown that TiB2 coating played a role in slowing the sodium penetration rate to the carbon cathode lining, which resulted in reduced swelling and cracking of carbon cathode block and then extended the life of aluminum reduction cells. The TiB2 coating was applied to the carbon cathode in 160 kA prebake cells, and the characteristic of evolution of carbon cathode was observed.