REFRACTORY LININGS CAPABLE OF RESISTING SODIUM AND SODIUM SALTS

摘要

: Refractory materials suitable for use in containers (e.g. cells and furnaces) which contact sodium or sodium salts at high temperature are disclosed. The refractory materials which come into contact with the sodium or sodium salts at temperatures above 700.degree.C should be aluminosilicate refractories having alumina:silica ratios of 0.85 or more. Such refractories having porosities of 25% or less are useful as protective layers to prevent penetration of the corrosive materials into other lining layers. Such refractories having porosities of 25-50% can be used as intermediate layers to provide some penetration resistance and some thermal insulation. The preferred refractories are aggregates prepared by calcining red mud (the byproduct of the extraction of alumina from bauxite by the Bayer process) at temperatures up to 1350.degree.C. These materials have the desired alumina:silica ratio and can also be made selfdensifiable (if desired) when contacted with sodium salts at temperatures above 830.degree.C.