Verfahren zur Herstellung von Waschmitteln

Solid detergent compositions are produced by drying a solution or slurry containing an alkali metal tripolyphosphate which also contains 0.05-2%, preferably 0.1-0.5%, by weight of the tripolyphosphate of a compound yielding calcium ions, especially calcium hydroxide or a mixture thereof with calcium sulphate di-hydrate. Suitably, the calcium compound is mixed dry with the tripolyphosphate and the mixture then added to the slurry or solution, after which the slurry or solution is heated. Other substances which may be present in the solution or slurry to be dried, e.g. by spray drying, include sodium tetrapropylene benzene sulphonate and alkyl sulphate, sodium sulphate, sodium and magnesium silicate, and methyl cellulose. The effect of the added calcium compound is to reduce the viscosity of the slurry. Specification 817,520 is referred to.