GB449751A - Manufacture of articles of ceramic bonded granular material - Google Patents

Abstract

In making abrasive articles, refractory bodies, porous plates, tiles &c., granular material is bonded together by firing in admixture with materials which yield a glassy cementing material containing oxides of phosphorus, aluminium and silicon. The amount of phosphoric oxide may be from 1 to 40 per cent, and alumina is present in proportions greater than necessary to form aluminium phosphate. Boric acid may be present. The phosphoric oxide may be added in the form of phosphoric acid, ammonium, sodium or other salts of phosphoric acid, or natural phosphates such as Wavellite, or Amblygonite. Alumina and silica may be added in the form of clay, feldspar, flint, &c., or may be derived wholly or partly from the granular materials, which may be crystalline alumina, silicon carbide, zirconia, magnesia, garnet, quartz, emery, &c. The bonding materials may be admixed with materials such as plastic clay or sodium silicate to yield a mouldable mass before firing or with temporary binding agents such as alginates, starch paste, dextrin, molasses, lignone, &c.