磷酸盐矿选矿废水的分次加药及加砂絮凝沉降

根据美国佛罗里达州某磷酸盐矿选矿废水含有超细胶体悬浮物的特性，选用美国Ciba化学品工业公司生产的阴子型高分子絮凝剂DPW-1355，在絮凝剂质量分数为0．05％，加药总剂量分别为18mL、25mL和40mL条件下对该废水进行分次加药及加砂絮凝沉降实验研究。结果表明：在相同的加药总剂量下，絮凝沉降速度均随着加药总次数的增加而提高，上清液浊度均随着加药总次数的增加而降低；在加药总剂量和加药总次数相同时，加质量分数为5％的砂与不加砂相比，絮凝沉降速度快得多，上清液浊度明显低。对分次加药及加砂改善絮凝沉降效果的机理进行了分析。实验结果对佛罗里达现有磷酸盐矿选矿废水和类似废水的絮凝沉降研究及其工业化应用具有一定的指导意义。

Flocculation and Settling of Phosphate Ore''''s Beneficiation Wastewater by Staged Addition of Flocculant and Sands

In light of the characteristic of a Florida phosphate beneficiation waste water that contained ultra-fine colloidal particles,an anionic macromolecule flocculant DPW-1355 produced by Ciba Speciality Chemicals,USA was used in the experimental research on its flocculation and settling by staged addition of the flocculant and sands,with the mass fraction of flocculant being 0.05% and the total dosage of flocculant being 18 mL,25 mL and 40 mL respectively.The results showed that,under the same total flocculant dosage,the flocculation and settling speed was raised with the increase in the stage number of flocculant addition while the turbidity of the supernatant was reduced accordingly.At the same total dosage and the same stage number of flocculant addition,when 5% sands(mass fraction) were added,the flocculation and settling speed was much higher and the turbidity of supernatant much lower,compared to that without sand addition.The mechanism of improving the flocculation and settling by staged addition of flocculant and sands was analyzed.The experiment results are of certain guidance significance to the research and industrial application of the flocculation and settling of the existing phosphate ore beneficiation wastewater and similar wastewater in Florida.