Pulverent cleansing and rinsing agents containing sodium tripolyphosphate and components customarily used in these agents are prepared by dry-blending the individual components, the sodium tripolyphosphate used containing 0.5 to 22.7% by weight water at the time of blending. The sodium tripolyphosphate preferably contains at least part of said water content as water of crystallization. When the sodium tripolyphosphate has a phase-I content of between 5 and 100%, it should preferably contain 0.5 to 8% water and when it has a phase-II content higher than 95% it should preferably contain 5-15% water. Sodium tripolyphosphate of the desired water content can be prepared from sodium tripolyphosphate containing less than 0.5% water by mixing it with water, e.g. in a fluidized bed, by exposing it to steam or by mixing with a proportion of sodium tripolyphosphate hexahydrate.ALSO:Sodium tripolyphosphate having a water content of 0.5 to 22.7% by weight, including water of crystallization, is prepared from sodium tripolyphosphate having a water content of less than 0.5% by mixing it with water, for example in a fluidized bed, by exposing it to steam, or by adding a proportion of sodium tripolyphosphate hexahydrate. Sodium tripolyphosphate having the aforesaid water content dissolves freely in water without caking.
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