Dry barrier mix in reduction cell cathodes

Abstract

Dry barrier mix (DBM) has been successfully tested as a replacement for barrier bricks in several reduction cell technology types and has been adopted as standard practice in all three of the Chinese cell technologies. DBM reacts with cathodic bath in-situ to form a glass-like barrier which retards the further penetration of bath components, protecting the lighter insulation from contact with the bath. Laboratory “cup tests” and plant trials show that silicate based DBM formulations are more effective than anorthite formulations or conventional refractory aggregates in formation of the glassy barriers. Cell bottom temperatures remain stable over the lifetime of the cell, indicating the barrier formation protects the insulating value. Cell autopsies show partial penetration of the DBM with barrier formation and preservation of the bottom portion of the DBM. Cell lining life is at least equivalent to that of brick barrier cells.