Low-density inorganic moulding and process for producing it

摘要

The description relates to a process for producing light, at least largely inorganic mouldings with a density < 400 kg/m<3>. To this end a light microporous filler with a powder density < 150 kg/m<3> is bonded with a geopolymer. The fillers used are, in particular, blown perlite and vermiculite. The geopolymer is produced by a stone-forming component, especially an oxide mixture containing silicon and aluminium oxides and an alkaline silicate solution as the hardener. The moulding compound consisting of the stone-forming component, the microporous filler and the hardener is poured into a possibly heated mould, pressed with a reduction in volume and removed from the mould after less than 3 min. The mouldings obtained contain a continuous phase of geopolymer with a dispersed phase of the light, microporous fillers. The mouldings have excellent resistance to temperature variations, a high temperature resistance, light weight and low heat conductivity.