Abstract: Wet process phosphoric acid contains many impurities，and purification can broaden its use.With methyl isobutyl ketone as solvent，the purification of wet process phosphoric acid by solvent extraction was studied.The influences of phase ratio，extraction time，stirring speed，and effect of stripping agent amount on the distribution coefficient of P2O5 and selectivity of F- and SO42- were researched.Results showed that phase ratio had obvious effects on the distribution coefficient of P2O5，but the selectivity had no significant effects on SO42-；the extraction time and stirring speed had no obvious influence on the distribution coefficient of P2O5；MIBK had great selectivity on F- and SO42-.When the phase ratio（volume ratio of organic phase to water phase） was 4∶1，the extraction time was 10 min，the stirring speed was 200 r/min，and stripping agent addition as the 15% of extractant volume，purification effect was better.

Key words: wet process phosphoric acid, solvent extraction, methyl isobutyl ketone, purification