Production of low density granular sodium tripolyphosphate

A process for preparing a granular sodium tripolyphosphate product of low frangibility and having a bulk density within the range of from about 0.45 g/cc to about 0.59 g/cc which comprises spraying water in an amount from about 36% to about 130% in excess of the amount stoichiometrically required for formulation of sodium tripolyphosphate hexahydrate, onto finely divided sodium tripolyphosphate feed material having a size distribution of at least 70% by weight -100 mesh and at least 95% by weight -50 mesh, to form an agglomerated product, calcining the agglomerated product at a temperature within the range of from about 320.degree. C. to about 550.degree. C., and recovering said granular sodium tripolyphosphate product.