Process for the preparation, preferably from waste materials, of silicate foam with closed pores, and the product produced by the process

摘要

The process of the invention characterized in that to 100 parts by weight of a silicate powder having 2000-8000 m2/g specific surface, 1-10 parts by weight of gas-forming material with particle size of 10-100 mum and 0.5-15 parts by weight of montmorillonite, 0.5-2 parts by weight of alkali hydrogen phosphate or alkali dihydrogen phosphate or a mixture of alkali metal phosphate and sodium silicate in form of aqueous solution, 0.01-5 parts by weight of rare earth metal oxide or a mixture of such oxides were added, then the mixture obtained is homogenized, pre-dried, coated with 1-5 parts by weight of titanium oxide and/or titanium oxide hydroxide and/or aluminum oxide hydroxide, then subjected to heat treatment at 720-1000° C., and the mixture obtained is molded. The subject of the invention: also the product of the above process.