Abstract: The invention relates to a furnace having an inner wall, an outer wall and a heat insulation arranged in between. The heat insulation is foamed up in situ, and hardened, from a mass which contains,per 100 parts by weight of a reactive solid (stone-forming component),40-250 parts by weight of a water-containing hardener which effects the hardening reaction of the reactive solid (stone-forming component) in the alkaline region,40-250 parts by weight of fillers and a blowing agent.The reactive solid used is preferably a reactive solid from the group comprisingI finely dispersed oxide mixture containing amorphous silica and alumina,II a glassy, amorphous electrostatic precipitator ash,III ground calcined bauxite,IV electrostatic precipitator ash from lignite-fired power stations,V undissolved, amorphous SiO.sub.2, especially from an amorphous, disperse-pulverulent, dehydrated or water-containing silica or from high-temperature processes (silica fume), andVI metakaolin.

Abstract: An inorganic, aqueous molding composition is described which can be hardened at low temperatures into molded parts having a high flexural stress at break.The molding composition is produced from electrostatic precipitator ash of high-temperature coal-burning power plants, this ash containing 45-55% by weight of vitreous SiO.sub.2 in addition to Al.sub.2 O.sub.3, or from calcined bauxite by reaction with an alkaline alkali silicate solution at a low temperature; fillers being optionally present.

Abstract: An exhaust gas catalyst support having hollow channels lined with .gamma.-Al.sub.2 O.sub.3 is formed by preparing an inorganic molding composition which actively hardens at 60.degree.-120.degree. C.; the molding composition containing an alkali silicate solution and a solid component reactive with the alkali silicate solution, which component can consist of an oxide mixture with contents of amorphous SiO.sub.2 and aluminum oxide and/or electrostatic precipitator ash from high-temperature coal-burning power plants and/or calcined ground bauxite and/or metakaolin; the hollow channels contained within the exhaust gas catalyst support are formed by reaction of aluminum rods or wires in the alkali silicate solution, with the simultaneous precipitation of alumina hydrate. In a subsequent heating step, the .gamma.-aluminum oxide lining is formed from the alumina hydrate, the lining serving for anchoring and fixation of a catalyst metal within the catalyst support.

Abstract: Facings for use as building components with a solid molded part constituting the visible side and a foam member of an inorganic and/or organic foam can be produced by shaping and heat curing from inorganic, aqueous molding compositions, wherein the molding composition contains a reactive oxide mixture, an alkali silicate solution, optionally alkali hydroxide, and fillers and auxiliary agents.

Abstract: Molded parts having high flexural strength, based on alkali silicates, can be produced by casting and/or press-molding and curing by heating from aqueous molding compositions which are prepared from an oxide mixture containing amorphous silicic acid and aluminum oxide, as well as, optionally, as an additional component, aqueous, amorphous, disperse-powdery silicic acid, dissolved SiO.sub.2, and alkali from alkali silicate solutions, optionally alkali hydroxide or its aqueous solutions and, if desired, fillers, by means of mixing under agitation. By addition of a blowing agent inorganic foamed products can be obtained.

Abstract: A support or base for low-vibration mounting of machines or the like is made by hardening a molding material in a mold. The base contains a hardened inorganic material with a density of 2.2 to 3.0, particularly 2.5 to 2.7 g/cm.sup.3, is made from(a) 15 to 30 weight % of an aqueous 30 to 65% potassium hydroxide-potassium silicate solution in which the SiO.sub.2 :K.sub.2 O molar ratio is 1.0 to 2.0:1;(b) 15 to 35 weight % of an oxide mixture containing amorphous SiO.sub.2 and aluminum oxide and/or hydrated amorphous silicic acid in the dispersed powder form and/or metakaolin;(c) 45 to 65 weight % of inorganic particulate fillers.The potassium silicate solution can be made by dissolving hydrated amorphous silicic acid in potassium hydroxide or its aqueous solution, and in this case, component (b) can consist entirely or partially of metakaolin.