PRODUCTION OF ALUMINUM POLYPHOSPHATE

摘要

PRODUCTION OF ALUMINUM POLYPHOSPHATE Aluminum polyphosphate is made. To this end, solid aluminum hydroxide and polyphosphoric acid which are used in proportions corresponding to an Al : P molar ratio of 1 : 2.5 to 1 : 3.5, are introduced separately from, but concurrently with, one another into a reaction zone kept at 150 to 200.degree.C. A moist friable consistency of the starting materials is maintained in the reaction zone by continuously mixing, kneading and comminuting them over substantially the entire period during which they are introduced into the reaction zone. The reaction is continued until a dry sandy powder is formed; and the powder is annealed at 400 to 600.degree.C over a period sufficient to yield a product undergoing a 0.5 to 1 % weight loss on ignition..