关键词: 磷酸二氢钾, 湿法磷酸, 氯化钾, 萃取

Abstract: Potassium dihydrogen phosphate has an important practical value in the current phosphate industry，and it was also applied in many industries，such as industry，agriculture，pharmacy，and foodstuff.To produce higher-quality potassium dihydrogen phosphate with lower cost of raw materials and simpler process is today′s need.Potassium dihydrogen phosphate was prepared by organic solvent extraction process with wet-process phosphoric acid and potassium chloride as raw materials. The study contents included：the influence of amount-of-substance ratio of potassium chloride to phosphoric acid on removal rate of F- during the solution preparation；the influence-of-amount of substance ratio of potassium chloride to phosphoric acid，reaction time，reaction temperature，and extraction phase ratio on extraction rate and impurities removal effect；the influence of different washing phase ratios on washing rate of the high-quality P2O5；relevant back-extracted and potassium dihydrogen phosphate concentrated crystallization processes etc..Optimum conditions for preparing high-quality potassium dihydrogen phosphate were obtained as follows:reaction temperature of 60 ℃，reaction time of 30 min，amount-of-substance ratio of potassium chloride to phosphoric acid of 1.0，and washing phase ratio of 12.Under those conditions the product purity was 97% and the recovery rate of P2O5 reached 96%，which met the first grate requirement of agricultural standard.

Key words: potassium dihydrogen phosphate, wet-process phosphoric acid, potassium chloride, extraction