Process of decomposing phosphate rock with phosphoric acid

Taking phosphate iron rock from the boundary areas of Hebei,Liaoning and Inner Mongolia provinces as the main raw materials,the reaction conditions of pre-decomposing phosphate rock with wet-process phosphoric acid was studied.Based on the orthogonal experiments,single factor experiments were carried out to determine the optimum reaction condition,it was that the reaction temperature was 80 ℃,the ratio of liquid to solid was 3∶1,reaction time was 90 min and mixed speed was 320 r/min.Under the reaction condition,the ratio of CaO/P2O5 was 0.17 in the pre-decomposed phosphoric acid(compared the ratio of CaO/P2O5 was 0.07 in wet-process phosphoric acid),which could save the sulphuric acid by 11% and save lime by 35%.