Process for producing alkali metal polyphosphates

Abstract

A process for producing an alkali metal polyphosphate, comprising heating a solution comprising a solvent, alkali metal ions, phosphate ions, and 3 to 50% by weight of organic matter, wherein the solution contains, in total, 5 to 65% by weight of the alkali metal ions and the phosphate ions, and the ratio M/P is 1.0 to 3.0, wherein M is the number of moles of alkali metal ions in the solution and P is the number of moles of orthophosphate ions in the solution, at a temperature of 800.degree. to 1200.degree. C. in the presence of excess air, optionally after the solution is at least partially dried to solid, to produce the alkali metal polyphosphate.

Dependencies are inferred from the claim text.