Improvements in processes for the manufacture of ceramic products, the products resulting from the same and their applications

摘要

Non-plastic substances such as silica, alumina, and magnesia are made into a mouldable mixture by the addition as a binder of a mono-or diphosphate of an earth or alkaline earth which is obtained by reducing a triphosphate with a mono- or bibasic acid other than phosphoric acid, the proportions being such that there is no excess of free acid. As an example, 100 kgs. of non-plastic material are mixed with a binder prepared from 1 to 10 kgs. tricalcic phosphate, 1 to 12 litres hydrochloric acid, and 5 to 10 litres water. The meta, pyro, or orthophosphates may be used. A small quantity of fluorides, fluoro-borates, or fluorophosphates may be added, as well as aluminium silicate and earthy carbonates or oxides. As a further example, 5 to 10 litres of the binder prepared as above are mixed with 100 kgs. sand, 0 to 20 kgs. carbonate of lime, magnesia, or dolomite, and 0 to 10 kgs. of oxide such as lime or magnesia. After moulding and drying, the products are baked at 1100 to 1500 DEG C. The material is suitable for bricks and mortar for furnace construction.