Abstract: The invention relates to a process for making sodium tripolyphosphate from wet-processed phosphoric acids which contain organic impurities, are neutralized and concentrated to give an orthophosphate solution or suspension which is sprayed in a spray tower in contact with one or more oxidants. More particularly, sodium tripolyphosphate, which is suitable for use in detergent slurries and causes the temperature determined after 1 and 5 minutes, respectively, in the hydration test (ROH) to be increased by at least 7.degree. C., is made; to this end, the wet-processed phosphoric acids are first admixed with the oxidants and then concentrated.