A method for the production of lining plates from warmth insulating ends masses for molds or warmth hoods

摘要

1,266,054. Heat-insulating slabs. FOSECO TRADING A.G. 3 March, 1970 [14 March, 1969], No. 13653/69. Addition to 1,080,647. Heading C3N. [Also in Division D2] A slab of heat insulating composition comprises, by weight, 1-20% cellulosic fibre, 1-20% of a difficultly water-soluble powdered alkali metal silicate which at 17‹ C. has a solubility in water, in one hour, of at most 10% by weight, preferably at most 5%, 0À5-5% of an alkali metal carbonate and a remainder consisting wholly or substantially wholly of granular or a mixture of granular and fibrous refractory, the said fibrous refractory constituting at most 10% by weight of the refractory mixture. The preferred difficultly water-soluble alkali metal silicate is sodium silicate having a ratio of SiO 2 to Na 2 O greater than 2 : 1, e.g. 3À375 : 1. The alkali metal carbonate is preferably sodium carbonate. The composition preferably comprises 4-20% by weight of cellulosic fibre and 4-20 % by weight of the difficultly water-soluble powdered alkali metal silicate. The slabs may be formed by vacuum dewatering through a fine mesh former an aqueous slurry of the solid constituents and thereafter drying the damp slabs. Since the bulk of the slurry liquid is expressed from the solid constituents, it is necessary to employ a relatively high proportion of alkali metal carbonate, e.g. 10-30% by weight, in order to provide in the final slab the required amount of alkali metal carbonate. Specific refractory materials are silica sand, silica flour and amosite asbestos. The cellulosic fibrous material may be waste paper. The slabs may be in the form of a hot top lining slab or a casting riser sleeve.