GB1217490A - Refractory heat-insulating composite products - Google Patents

Abstract

1,217,490. Flat tops and mould risers. FOSECO TRADING A.G. 13 Dec., 1967 [30 Dec., 1966], No. 58391/66. Heading B3F. [Also in Divisions B5 and D2] A heat-insulating refractory product comprises a first layer of fibrous material, granular refractory material and a synthetic-resin binder, and a second layer of a bonded or unbonded mass of fibrous refractory material or a felted organic material, the fibre content of the second layer being 30-80% by weight. The product may be a slab or sleeve for lining hot-tops and risers when casting metals, the first layer being on the side in contact with the metal. The first layer may be thinner and denser than the second. The fibrous material of the first layer may be organic or refractory or a mixture of the two. The refractory filler of the first layer may be silica flour, zircon or olivine flour, magnesia or a refractory silicate, and the binder phenolformaldehyde or urea-formaldehyde. The second layer may contain both organic and inorganic fibres, binder and refractory filler. Either layer or both may contain a sintering agent, e.g. sodium silicofluoride or sodium nitrate. The two layers may be formed by successive deposition from aqueous slurries on a former, or by forming the two layers separately and then sticking them together. In examples, the fibre of the first layer is : (1) amosite asbestos and paper pulp; (2) asbestos; (3)" Kaowool" (Trade Mark); (4) paper; (5 and 6) slag wool and paper; (7 and 8) calcium aluminium silicate fibres and paper; in each case the binder is phenol-formaldehyde and the granular refractory silica flour. In further examples: (9-14) the second layer comprises calcium silicate fibres, paper, phenol-formaldehyde and silica flour and is used with the first layer of Example 1 or 4; (15-17) the second layer is similar but has a sodium silicate binder (instead of phenol-formaldehyde) and is used with the first layer of Example 1; (18-20) the second layer is similar to those of Examples 9-14 but has amosite instead of calcium silicate fibres and is used with the first layer of Example 1, 2 or 3. In yet further examples, second layers used with the first layer of Example 1 comprise calcium silicate fibres, paper and: (21-23) phenol-formaldehyde and flyash; (24-26) sodium silicate and flyash; (27) phenolformaldehyde and silica flour; (28) phenolformaldehyde, silica flour and flyash; and (29) phenolformaldehyde, silica flour, flyash and coal dust.