Abstract: Solvent reflux extraction method,which improved the traditional wet-process phosphoric acid and solvent extraction method,was applied to purify wet-process phosphoric acid.In this process,ammonium phosphate was produced by taking advantage of low solubility characteristic of ammonium phosphate in extracting agent,so as to achieve the goal of clean,high efficient,and low energy consumed production.Influences of reaction temperature,extracting agent,and phase ratio (volume ratio of oil phase to water phase) etc.on the yield and purity of ammonium phosphate were investigated.Optimum process conditions were as follows:normal butanol as extracting agent,extraction phase ratio was 2,reflux extraction phase ratio was 2.8,and washing and purifying phase ratio was 0.5.Under those conditions the final yeild of ammonium phosphate was more than 89% and impurity Ca<SUP>2+</SUP>and Cl<SUP>-</SUP> in solid product were less than 10% and 6.5% respectively.Experiment results showed that comparing with traditional ammonium phosphate production technology solvent reflux extration method had the advantages of simple production flow,low energy consumption,less by-products and environment pollution.However,all aspects of study were still in laboratory research stage.