Process for making granulated condensed phosphates

A process for converting pulverulent, water-soluble, condensed phosphates of the following general formula (I)

• M.sub.2 O(MPO.sub.3).sub.n
• in which M stands for sodium, potassium or ammonium and n stands for a number between 4 and about 100, to a granulate, wherein the pulverulent, water-soluble, condensed phosphate is thoroughly agitated and granulated in the presence of water and of a phosphate salt other than the condensed phosphate, which comprises:
• thoroughly agitating and granulating a condonsed phosphate of the general formula (I) or a mixture of the phosphate with an anhydrous or partially hydrated alkali metal phosphate in the presence of water and aiding the formation of a granulate from the pulverulent material with a granulating aid comprising an ammonium polyphosphate of the following general formula (II)
• H.sub.(n-m)+2 (NH.sub.4).sub.m P.sub.n O.sub.3n+1
• in which n stands for an integral average value of 3 to 1000, m stands for a whole number of up to n+2, and the m/n-ratio is between about 1.0 and 1.67, the water being used in a proportion of about 0.05 to 5.0 weight %, the ammonium polyphosphate of general formula (II) being used in a granulation-assisting proportion of about 0.003 to 1 weight %- and the alkali metal phosphate being used in a proportion of up to about 40 weight %, the percentages being all based on the quantity of the condensed phosphate of general formula (I).