GB315856A - Improvements in or relating to the manufacture of refractory articles - Google Patents

Abstract

315,856. Hartford-Empire Co., (Assignees of Willetts, P. G.). July 21, 1928,[Convention date]. Refractory substances.-Firebricks and like refractory articles are composed to have substantially the following chemical analysis : 39.9 to 34.89 per cent of SiO2, 61.39 to 56.38 per cent of Al2O3, 1.11 to 0.89 per cent of Fe2 O3, 2.72 to 2.65 per cent of TiO2, 0.28 per cent of CaO, 0.27 to 0.25 per cent of MgO. 0.06 to none of Na2O and loss on ignition from 0.28 to 0.22 per cent. The bricks, &c. are made of white bauxite, Georgian Klondike white kaolin, and a hard fireclay known as Georgian G<1> clay, or of other clays and bauxites having substantially the same analytical composition and properties. In an example, 128 parts of raw white bauxite, 87 parts of Georgian Klondike white kaolin and 21 parts of Georgian G<1> clay are ground to extreme fineness and mixed in the presence of water; this composition is calcined at 2,850‹ F. or higher and broken down to pass an 8 mesh screen; 60 parts of this grog are mixed with 40 parts of raw mixture, and the composition is moulded under a pressure of from 1 to 2¢ tons per sq. in., dried, and fired at 2,850‹ F. or higher. The finished material comprises a glassy phase and a crystalline phase having the properties of mullite and present in minute crystals uniformly distributed.