A process for preparing detergent raw materials

The invention concerns a process for preparing solid raw materials for washing agents by simultaneously drying and granulating aqueous pastes of anionic and/or amphoteric surfactants in a horizontal thin film evaporator or drier with rotating fittings, the drying process being carried out at a temperature ranging from 120 to 130 DEG C. Hydrolysis-free, light-coloured, pourable products are obtained which have a uniform grain spectrum and high bulk density.