磷矿浮选回水中SO_4^(2-)及总硬度去除试验研究

Experimental Study on Removal of SO_4^(2-) and Total Hardness in Circulating Water of Phosphate Rock Flotation

为解决离子在浮选回水中的积累问题,采用混凝沉淀法去除磷矿浮选回水中的SO42-及总硬度。研究结果表明:pH值对混凝效果影响较大。利用石灰乳调节废水pH值至8后,采用Na2CO3、PAC与PAFC联用处理工艺效果较好,Na2CO3、PAC和PAFC的适宜投加量分别为2000mg/L、600mg/L和1400mg/L,在此条件下,SO42-和总硬度去除率分别达到70.15%和85.05%。

To solve the problem of ion accumulation in circulating water of phosphate rock flotation, a coagulation- sedimentation method was introduced to remove total hardness and SO42-. The results show that pH value has crucial effect on coagulation. After using lime milk to adjust pH value of circulating water to around 8, good index can be obtained with a combined usage of Na2CO3, PAC and PAFC with the optimized dosage as 2 000, 600 and 1 400 mg/L, respectively, through which the concentration of SO42- and total hardness can be reduced by 70.15% and 85.05%, respectively.