鼓泡结晶塔内脱除磷酸中Mg^(2+)的研究

Process of removing Mg^(2+) in bubble column crystallizer

采用鼓泡结晶塔净化磷酸并以较难脱除的Mg^(2+)的分离效果为指标,考察通气速率、晶种加入量、晶种加入温度、降温速率等因素对晶体产率和Mg^(2+)分离效果的影响。研究得到较优的工艺条件为:通气速率50mL/min,晶种加入量0.5%~1%,晶种加入温度295.15K,降温速率0.06K/min。实验证明鼓泡结晶塔净化磷酸是可行的,该法能耗低、污染小,一次结晶可以使原料中Mg^(2+)净化率达60%。本研究成果为鼓泡结晶塔净化工业磷酸进而制备高纯度磷酸生产高纯磷化工产品奠定了基础并对其工业化具有指导意义。

The effects of aeration rate, crystal seed amount, temperature and cooling rate on the crystal yield and Mg2＋ sepa- ration efficiency were investigated using the bubble column crys-tallizer for purifying phosphoric acid and Mg2＋ separation efficien- cy as index. To obtain the better process conditions, the ventila.. Tion＇rate is 50 mL/min, seed amount 0.5% to 1%, seed addition temperature 295.15 K and cooling rate 0.06 K/rain. The experi mental results show that the purification of phosphoric acid is fea- sible. This method has a low energy consumption and little pc, lh tion and can make the purification rate of Mg2＋ in raw materials up to 60%. The research results laid a foundation for purification of industrial phosphoric acid and production of high purity phos- phoric acid and high purity phosphorus chemical products.