Verfahren zur Herstellung von körnigem Alkalitripolyphosphat hoher Abriebfestigkeit und mit hohem Schüttgewicht

Production of granular alkali metal tripolyphosphate of high abrasion resistance and high apparent density. An alkali metal tripolyphosphate of which between 10 and 40 percent of its particles have a size smaller than 0.03 mm, the balance particles having a size of between 0.03 and 0.4 mm, is granulated by spraying an alkali metal orthophosphate solution thereonto; the resulting granules are dried; undersize and oversize particle fractions are separated from the dried granules; and the remaining fraction of particles is annealed at temperatures of between 300 and 600 DEG C.