磨矿强化浮选粉煤灰中未燃尽炭试验研究

为了高效利用贵州某高炭粉煤灰中的未燃尽炭,进行了浮选试验研究,采用正交试验和单因素试验考察了捕收剂用量、起泡剂用量、矿浆浓度、充气量和磨矿细度对浮选效果的影响。结果表明:在捕收剂WZ用量1 800 g/t、起泡剂YC用量200 g/t、矿浆浓度25%和充气量0.3 m³/min条件下,在浮选前增加磨矿,磨矿细度从未磨矿时原灰-0.075 mm粒级占42.20%提升到-0.075 mm粒级占97.40%时,浮选完善指标从35.84%提高到45.69%。采用一粗两精一扫、中矿再选试验流程,可获得可燃物含量60.87%、可燃物回收率77.64%的精炭,以及烧失量分别为4.57%和9.55%的两种尾灰。磨矿不仅能够使颗粒变细,还可使未燃尽炭内部新鲜表面暴露,提高其疏水性,强化浮选。

Efficient Use of Unburned Carbon in Fly Ash by Grinding-Flotation

In order to make an efficient use of unburned carbon in a high-carbon fly ash from Guizhou Province, after a flotation test, an orthogonal test and single factor test were then performed to investigate effects of the amount of collector, the amount of foaming agent, the concentration of pulp, aeration volume and grinding fineness on the flotation result. It is shown that with the collector WZ at an amount of 1 800 g/t, frothing agent YC at an amount of 200 g/t, pulp concentration at 25% and aeration volume of 0.3 m³/min, the index for flotation improvement is increased from 35.84% to 45.69% by adding a grinding stage before the flotation. It is shown that the grinding size is increased from the fineness of -0.075 mm 42.20% (raw fly ash before grinding) to -0.075 mm 97.40%. Then, the test by adopting the circuit consisting of one rougher, two cleaner and one scavenger, followed by redressing of the middlings yields the concentrated carbon with the content of combustibles of 60.87% at 77.64% recovery. It is found that the grinding process can not only make the particles finer, but also make the fresh surface inside the unburned carbon exposed to the air, leading to an increased hydrophobicity and improved flotation effect.