Some More Words on Barriers for Electrolyte Penetration

5 Some More Words on Barriers for Electrolyte Penetration 

An alumina silica refractory is far from being the optimal material for a refractory barrier. Although some theoretical considerations on the silica/alu-mina ratio may exist, other variants should be found. 

There is a long history of trials with different barrier materials silica block, silica powder, alumina brick, alumina powder, red constructional brick, mullite brick, various combinations of muUite brick of fireclay brick in the upper and lower layers. 

Chemical considerations suggest that tin oxide, ferric nickel spinel, zinc oxide, and their variations might be good barrier materials however, these compounds don t meet economic considerations. Also, these compounds are not stable to sodium vapor. 

SiC-based refractories look (in the form of preshaped or not previously shaped castables or mortars)like more probable barrier materials. 

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