Method for the production of foam ceramics and shaped articles thereof

Claim 1

In the known method of producing foamed ceramics by heating an aqueous starting mixture to a temperature between 700° and 1100° to form a sintered porous mass, said aqueous starting mixture containing components which are know to form a viscous, sintered and porous mass upon being heated to said temperature, the improvement which comprises: a. incorporating into said aqueous starting mixture a material selected from the group consisting of blast furnace slag, Portland cement and aluminate cement, b. allowing said admixture of step (a) to set for a sufficient time for said admixture to form a unitary solid mass, c. crushing the solidifed mass of step (b) into granules with a size of 1 - 20 mm, d. subjecting the granules of step (c) to a first stage heating at a temperature below about 700° C in order to effect water removal and primary pore formation, e. subjecting the product resulting from step (d) to a further heating at a temperature within the range of 700° - 1000° C so that the pores formed during the first stage heating are partly destroyed and finer new pores are formed instead, which establishes the structure of the finished foam ceramic.