Flotation and adsorption of muscovite using mixed cationic-nonionic surfactants as collector
Flotation and adsorption of muscovite using mixed cationic-nonionic surfactants as collector
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DOI：
10.1016/j.powtec.2015.02.019
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发表时间：
2015-05-01
影响因子：
5.2
通讯作者：
Sun, Wei
中科院分区：
文献类型：
--
作者：
Wang, Li;Hu, Yuehua;Sun, Wei
通过浮选试验研究了氯化十二胺（DDA）/辛醇（OCT）混合表面活性剂对白云母浮选的性能，并通过接触角测量、表面张力和分子动力学（MD）模拟阐明了它们在白云母和空气/水界面上的吸附机制。浮选结果表明，在仅存在 DDA 的情况下，当 pH 值升高时，白云母的回收率迅速下降，而在比例为 2/1 的混合 DDA/OCT 表面活性剂存在下，在较宽的 pH 范围内，白云母的回收率较高（>77%）。接触角测量进一步证实该混合物显示出比 DDA 更强的捕收能力，并且是白云母浮选的优异捕收剂。 DDA、OCT及其混合物的表面张力表明，该混合物在降低空气-水界面张力方面比DDA更有效，并且表现出更好的表面活性。 MD模拟表明，混合物与白云母的相互作用主要通过静电吸引和氢键作用。 DDA 离子在混合物与白云母之间的相互作用中起主导作用。 OCT 分子通过氢键相互作用和与 DDA 离子的疏水缔合而共吸附到白云母上。与DDA相比，在混合表面活性剂存在下，白云母表面形成了致密的单分子层，表明白云母具有更强的疏水特性。 (C) 2015 Elsevier B.V. 保留所有权利。
The performance of the mixed dodecylamine chloride (DDA)/octanol (OCT) surfactants on muscovite flotation was investigated using flotation tests, and their adsorption mechanisms on muscovite and air/water interface were clarified using contact angle measurement, surface tension and molecular dynamics (MD) simulations. The flotation results indicate that the recovery of muscovite rapidly decreases when the pH increases in the presence of only DDA, whereas the recovery of muscovite is high (>77%) over a wide range of pH in the presence of the mixed DDA/OCT surfactants with a ratio of 2/1. Contact angle measurements further confirm that the mixture displays a stronger collecting power than DDA and is a superior collector for the muscovite flotation. The surface tensions of DDA, OCT and their mixture indicate that the mixture is more efficient than DDA at decreasing the air-water interfacial tension and exhibits much better surface activities. MD simulations show that the mixture interacts with the muscovite mainly through electrostatic attraction and hydrogen-bonding. DDA ion is dominant in the interaction between the mixture and muscovite. OCT molecules are co-adsorbed onto the muscovite through the hydrogen-bond interaction and hydrophobic association with DDA ions. Compared with DDA, a well-compacted monolayer is formed on the muscovite surface in the presence of mixed surfactants, indicating a much stronger hydrophobic character of muscovite. (C) 2015 Elsevier B.V. All rights reserved.