Method of producing hydrated sodium tripolyphosphate composition

Claim 1

IN THE METHOD OF PRODUCING HYDRATED GRANULAR SODIUM TRIPOLYPHOSPHATE OF LOW BULK DENSITY WHEREIN ANHYDROUS SODIUM TRIPOLYPHOSPHATE FEED MATERIAL, CONTAINING AT LEAST 10 PERCENT BY WEIGHT OF ANHYDROUS SODIUM TRIPOLYPHOSPHATE HAVING A PARTICLE SIZE BELOW 100 MESH, IS HYDRATED WITH NOT IN EXCESS OF 105 PERCENT OF THE THEORETICAL QUANTITY OF WATER NECESSARY TO PRODUCE THE HEXAHYDRATE, AND WHEREIN THE WATER IS DISTRIBUTED UNIFORMLY OVER SAID ANHYDROUS FEED MATERIAL WHILE IT IS BEING AGITATED AT A RATE TO KEEP THE HYDRATING MIXTURE BELOW 80*C AND TO PRODUCE AN AGGLOMERATED HYDRATE BY THE ACTION OF THE WATER, GRINDING THE COARSE, AGGLOMERATED HYDRATE, SEPARATING A PARTICLE SIZE RANGE OF ABOUT :20 TO +60 MESH AS PRODUCT, AND RECYCLING REMAINING HYDRATED SODIUM TRIPOLYPHOSPHATE FINES TO THE FEED MATERIAL THE IMPROVEMENT WHICH COMPRISES ADDING TO SAID ANHYDROUS SODIUM TRIPOLYPHOSPHATE FEED MATERIAL PRIOR TO HYDRATION AT LEAST ABOUT 2 PERCENT BY WEIGHT OF AN AKALI META PYROPHOSPHATE AND RECOVERING A SODIUM TRIPOLYPHOSPHATE HEXAHYDRATE PRODUCT WHOSE BULK DENSITY HAS BEEN REDUCED TO A RANGE OF FROM 0.65 TO 0.71 G/CC.