A process based upon solvent extraction has been developed for the recovery of phosphoric acid from a leaching liquor obtained by decomposition of phosphate rock with sulfuric acid. Using Di-n-Butyl Sulfoxide (DBSO) as extractant and multistage counter-current extraction and stripping

pure phosphoric acid or potassium dihydro-gen phosphate can be produced on one hand

and precipipated calcium phosphate on the other. The proportion of both products may be economically adjusted in accordance with varying demands. This process will leave an effluent which is less polluting than any existing process.