Experimental study on technological conditions for manufacture of high analysis enriched superphosphate by mixed acid process

The experiment is introduced for high analysis enriched superphosphate〔available w (P_2O_5) ～34%〕by sulfuric and phosphoric acid mixture decomposing ground phosphate rock. The influences of mixed acid consumption, concentration, temperature and alternated phosphoric acid amount on acidulated rate of phosphate rock are discussed. The optimum technological parameters are also determined by orthogonal experiments for mixed acid w (H_3PO_4+H_2SO_4)66%～69%,temperature 70～80℃, alternated rate of phosphoric acid 50%～54%, mixed acid consumption 93%～97% theoretical acid consumption. Some factors disturbing slurry solidified and quality controlled are analyzed.