Abstract: Purification of wet phosphoric acid（WPA） was studied by solvent extraction with a mixture of tri-n-butyl phosphate（TBP） and diisopropyl ether（DIPE）.Influences of factors，such as volume fraction of TBP，phase ratio，extraction time，agitator speed，and the adding amount of re-extraction agent on WPA extraction effect were investigated and the process conditions were determined as follows：the volume ratio of TBP and DIPE was 1∶1，volume ratio of organic phase and water phase was 4∶1，extraction time was 25 min，agitator speed was 300 r/min，and the adding amount of re-extraction agent was 20% of the volume of the organic phase.Under those conditions，the TBP and DIPE extraction system had a good separation ability for metal cations and fluoride ions.

Key words: wet-process phosphoric acid, solvent extraction, purification, tri-n-butyl phosphate, iisopropyl ether