| 摘要 |
A refractory material capable of air setting at room temperatures to form a composition having high strength which is maintained up to firing temperature comprises a refractory clay such as Kaolin calcined kyanite, or ball clay, a refractory filler such as ceramic grog, and a water-soluble, colloidal aluminium phosphate, ranging from mono to di-aluminium phosphate, serving as a binder. The aluminium phosphates used may be prepared as described in Specification 597,169, [Group III], and have an Al:PO4 ratio of 1-2 : 6. The material may contain 15-25 per cent high-grade refractory clay and 2 1/2 -10 per cent binder on a dry basis. With phosphates of high alumina content, aluminium or ammonium chloride, sulphate, or nitrate may be added to reduce the effect of hydrolysis and to increase the rate of solution; phosphoric acid solutions of proteins, carbohydrates, polyethylene amines, and like compounds may also be added. The compositions may be formed in wet or dry form, and, in the atter case, the grog particles may be coated with the phosphate binder. Approximately 0.25 per cent of a wetting agent such as a sodium alkyl naphthalene sulphonate may be incorporated. The material may be used as a ramming-mixture for patching, as a lining, or for forming crucibles saggers and small furnaces. Specification 462,781, and U.S. Specification 1,949,038 also are referred to. |
