鞍山微细赤铁矿的油酸钠诱导剪切疏水絮凝和浮选(英文)

Shear hydrophobic flocculation and flotation of ultrafine Anshan hematite using sodium oleate

讨论搅拌速度、絮凝时间、矿浆pH值和油酸钠浓度等对鞍山微细赤铁矿的油酸钠诱导剪切疏水絮凝和浮选的影响。结果表明:剪切搅拌速度、絮凝时间、矿浆pH和油酸钠浓度对该系统疏水性絮凝均有显著影响;最佳疏水絮凝条件为:剪切搅拌速度1400r/min、剪切搅拌时间20min、矿浆pH=9和油酸钠浓度3.94×10-4mol/L;絮凝浮选回收率比未絮凝浮选的有明显提高。根据扩展DLVO理论,计算出油酸钠诱导疏水微细赤铁矿颗粒的总相互作用势能,证实该系统的疏水絮凝状态主要受颗粒间双电层排斥能和疏水作用势能支配,双电层排斥能使颗粒间的作用存在能垒,机械搅拌使颗粒获得动能克服能垒,随着颗粒的进一步靠近,颗粒间疏水作用势能显著增大,引起颗粒团聚。

Effects of stirring speed and time, pH and sodium oleate concentration on the shear hydrophobic flocculation of ultrafine Anshan hematite with sodium oleate as the surfactant were discussed. The results show that these parameters significantly affect the shear hydrophobic flocculation of ultrafine hematite. The optimum conditions for the flocculation are： stirring speed 1 400 r/min, flocculation time 20 min, pH 9 and sodium oleate concentration 3.94×10-4 mol/L; the flotation recovery of hematite flocs is remarkably high compared with non flocculated ultrafine hematite. According to the extended DLVO theory, the total interaction potential of Anshan ultrafine hematite was determined. The calculation results indicate that the hydrophobic flocculation state of the ultrafine hematite-sodium oleate system is mainly dominated by electric double layer repulsive interaction potential and hydrophobic interaction potential. A mechanical agitation is required to impart particles a kinetic energy to overcome potential barrier between them due to the existence of electric double layer repulsive interaction potential. Those particles further approach to form flocs due to the significant increase of the hydrophobic interaction potential.