半水法湿法磷酸萃取条件对P_2O_5回收率的影响

Effect of Extraction Conditions of Wet-process Phosphoric Acid by Hemihydrate Process on P_2O_5 Recovery Rate

采用连续投料方式模拟半水法湿法磷酸生产工艺,研究了料浆液固比、搅拌速度、过量硫酸含量、液相P2O5浓度及反应温度对P2O5回收率的影响。结果表明,随着料浆液固比、反应温度的增大,P2O5回收率逐渐增大,随着搅拌速度、过量硫酸含量、液相P2O5浓度的增大,P2O5回收率先增大后减小。通过正交试验优化得到最优萃取工艺条件为:液固比3.0∶1、搅拌速度165 r/min、过量硫酸含量12%、液相P2O5浓度46%、反应温度95℃,此时P2O5回收率可达98.16%。

The production of Wet-process Phosphoric Acid by hemihydrate process under continuous feeding operation was simulated. The effects of several influence factors （liquid-solid ratio, stirring rate, content of excess sulfuric acid, P2O5 concentration and temperature） on P2O5 recovery rate were studied. The results showed that with the increase of liquid-solid ratio and temperature, P2O5 recovery rate was increased; while P2O5 recovery rate first increased and then decreased with the increase of stirring rate, content of excess sulfuric acid and P2O5 concentration. The best process condition was obtained through orthogonal experiment： liquid-solid ratio was 3.0 ： 1, stirring rate was 165 r/min, the content of excess sulfuric acid was 12 %, P2O5 concentration was 46 % and 95 ℃. In such conditions, the recovery of P2O5 reached 98.16 %.