| 摘要 |
<p>1278473 Fibrous refractory composition FOSECO TRADING AG 5 Jan 1970 [30 Jan 1969] 5257/69 Heading C3N [Also in Division D2] A refractory composition particularly for use in hot topping applications comprises at least two fibrous materials selected from calcium silicate fibres, aluminium silicate fibres and asbestos fibres, and either organic fibre or granular refractory filler or both, the maximum proportions of each ingredient in the composition being, by weight Calcium silicate 35% Aluminium silicate 55% Asbestos 35% Organic fibre 40% Granular refractory filler 50% and a binder. The binder may be colloidal silica, alumina or zirconia sols, aluminium phosphate, phosphoric acid, sodium silicate or an alkyl silicate. The particle size of any sol binder employed is preferably less than 100 Á. The binder is preferably present in an amount 5À55 parts by weight dry binder per 100 parts by weight of the other ingredients. The aluminium silicate fibres should preferably have lengths in the range 12-250 mm., whilst the calcium silicate fibre, which may be synthetic pure calcium silicate fibre or slag wool, should preferably have lengths in the range 12-75 mm. The asbestos should preferably be the amosite type, have a water content of 2-3% by weight and having lengths in the range 9-18 mm. The organic fibre may be pulped newsprint, wood pulp, sawdust, cotton scrap, bagasse and synthetic materials such as rayon, nylon and acrylic fibres of which pulped newsprint is preferred. Mixtures of two or more fibres may be used. The granular refractory material may be fine silica, aluminium silicate, diatomite (preferably calcined), furnace aggregate, vermiculite, perlite, grog, chamotte, alumina, magnesia, silica, coke, olivine or chromite. The composition may be formed into sheets or slabs by conventional vacuum dewatering techniques and the finished article may be damp and flexible so that it conforms to the desired shape in situ in an ingot mould, head box or riser, or a hard dry rigid product.</p> |
