Method for forming a quickly hardening, inorganic foam

The invention relates to a method for forming a quickly hardening, inorganic foam on the basis of the reaction of two components: a) a solid component in the form of a reactive powder, which simultaneously has both framework-forming properties and pore-forming properties, and b) a liquid component in the form of an alkali metal silicate (water glass), wherein the reactive powder contains 45-65 wt% of aluminum oxide, 10-20 wt% of aluminum nitride, and 5-15 wt% of metal aluminum as essential constituents, the alkali metal silicate has a molar ratio of silicon oxide to metal oxide of 1.0-2.2, and the two components are mixed at a weight ratio of powder to liquid component of 0.5-2 to form a paste, from which a foam body having a bulk density less than 0.7 g/cm3 is then formed in an exothermic reaction in less than 10 minutes.