Method of producing light insulating and building elements from amorphous silica obtained upon the production of ferrosilicon

摘要

A method of producing light insulating and building elements from amorphous silica obtained upon the production of ferrosilicon is proposed, in which amorphous silica having an SiO2 content of 82 to 95 % by weight and a specific surface area of 20 to 30 m<2>/g, which is obtained in the production of ferrosilicon, is homogenised in the dry state with calcium hydroxide in a CaO/SiO2 ratio of 0.8 to 1.0, an amount of water 10 to 20 times the weight is stirred in and heated at 180 DEG to 200 DEG C at constant volume for 2 to 4 hours with agitation, whereupon 3 to 5 % by weight of reinforcement fibres are added to the suspension, the mass is shaped, and the shaped parts are dried for 5 to 10 hours at a temperature of 50 DEG to 105 DEG C. The elements obtained are characterised by a low weight per unit volume and a high insulating capacity.