Process for the manufacture of spray dried detergents containing nonionic tensides

In the process of the production of spray dried detergent powders containing at least one nonionic surfaceactive compound of the class of polyoxyalkylene glycol derivatives comprising the steps of spraying an aqueous slurry of the detergent ingredients in a conical pattern into a fall space while passing a large volume of air therethrough at an inlet temperature in excess of 150.degree. and recovering said spray dried detergent powders containing at least one nonionic surface-active compound of the class of an ethoxylation product of an alcohol selected from the group consisting of alkanols having 10 to 20 carbon atoms, alkenols having 10 to 20 carbon atoms, vicinal alkanediols having 10 to 20 carbon atoms and alkylphenols having 10 to 20 carbon atoms in the alkyl, said ethoxylation product containing from 5 to 20 oxyethylene units, and conventional detergent components of the following type:

• anionic surface-active compounds, zwitterionic surface-active compounds, builder salts, soil suspending agents, optical brighteners, neutral salts, magnesium silicate and hydrotropic substances, the improvement consisting of utilizing, as said aqueous slurry, an aqueous slurry containing from 50% to 90% by weight of the total solids of the final spray dried detergent including from 0 to 5% at most, by weight of the total solids, of said at least one nonionic surface-active compounds, said aqueous slurry having a solids content of from 65% to 75% by weight, and injecting into said fall space above said conical spray pattern a free-flowing, water-soluble powder granulate consisting of the remainder of the total solids of the final spray dried detergent selected from the group consisting of alkali metal polymeric phosphates and mixtures of alkali metal polymeric phosphate and alkali metal silicates having an amount of said at least one nonionic surface-active compound of the class of polyoxyalkylene glycol derivatives deposited thereon in such a manner as to form a granulate, having a particle size predominately in the range of from 0.1 to 0.8 mm, where the ratio by weight of solids other than said nonionic surface-active compound to said nonionic surface-active compound in said granulate amounts to 20:1 to 8:1.