| 摘要 |
A heat-insulating material of cellular structure is formed by the thermal reaction of an aqueous mixture of calcium oxide, silica and inorganic fibres together with a hydrophilic colloid which absorbs a large amount of water which on expulsion leaves cells or voids, and which is rendered substantially inert to reabsorption of water by reacting with calcium oxide. In an example, a slurry is formed with 4 parts by weight of lime and 6 1/2 of silica, both preferably ground to pass a 140 mesh inch screen, together with 2 1/4 of uncalcined bentonite and 2 1/4 of graded asbestos in 85 of water and the mixture cooked at a temperature below 212 DEG F. till it attains a viscous consistency. The mixture is then poured, extruded, or otherwise deposited into moulds and subjected to heat, and preferably to steam treatment in an autoclave and finally dried to give a product which may be used up to 1,000 DEG F. |
