Abstract: A ceramic foam filter, particularly for filtering molten iron, is formed from a composition comprising silicon carbide, alumina, silica derived from colloidal silica sol and alumino-silicate fibres, which has been fired at such a temperature that the filter has a ceramic matrix in which the alumino-silicate fibres are substantially dissolved. The filter is fired at a minimum of 1150.degree. C. and preferably within the range from 1200.degree. to 1300.degree. C. Preferably the filter is formed from an aqueous slurry having a solids content comprising by weight 20-50% silicon alumina, 20-50% alumina, 1.5-5.0% silica derived from colloidal silica sol and 1-3% alumino-silicate fibres.