Preparation of granular sodium tripolyphosphate products from screen undersize sodium tripolyphosphate particles

摘要

Screen undersize sodium tripolyphosphate (STPP) particles are compacted, milled and moisturized by adding a sufficient amount of water thereon to produce a material containing on the average between about 15% and about 35% by weight moisture. The moisturized material is calcined to a temperature within the range of from about 300 DEG to about 600 DEG C., to produce a granular STPP product having a low friability, high absorptivity, and a bulk density within the range of from about 0.65 to about 0.87 g/cc.