浓缩湿法磷酸中杂质颗粒的沉降特性

Settlement Properties of Impurities in the Concentrated Wet-process Phosphoric Acid

随着磷矿品位的日益下降,浓缩湿法磷酸中的杂质含量高达8%,给磷酸的输送、储存和后续加工带来了诸多困难。为了加快磷酸中杂质颗粒的沉降与净化,采用添加絮凝剂的方法来处理浓磷酸中的杂质,对比了添加絮凝剂前后对浓磷酸中杂质颗粒的沉降特性的影响,考察了温度对自然沉降和絮凝沉降的影响以及絮凝剂用量的变化对絮凝沉降速率的影响。结果表明,当沉降温度为60℃时沉降速率最大;絮凝沉降平均速率是自然沉降的2倍;磷酸浓度及杂质含量的不同导致絮凝剂最佳用量不同。

With the deficiency of high - grade phosphate rock, the amount of impurities reaches eight percent in the concentrated phosphoric acid, which caused much difficulty in transportation, storage and subsequent machining technology. To accelerate the settlement and purification of impurity particles in phosphoric acid, addition of floeculant to treat im- purities was studied, and the effect of temperature on natural settlement and flocculent sedimentation, as well as flocculent dosage on the rate of floeculation were investigated. Result showed that the maximal settlement was at 60℃ , at which the rate of flocculent sedimentation was two times faster than that of natural settlement, and the difference of concentration and content of impurities led to the difference on the optimal usage of flocculent.