油酸钠体系下Pb^(2+)对白云母的活化机理研究

The Activation Mechanism Study of Pb^(2+) about Muscovite in Sodium Oleate System

在油酸钠体系下研究了Pb^(2+)对白云母浮选行为的影响,采用浮选溶液化学、Zeta电位、IR、XPS等手段研究了Pb^(2+)活化白云母的机理。结果表明:在p H值为9,油酸钠用量为9.20×10-4 mol/L的条件下,9.06×10-5 mol/L的Pb^(2+)可使白云母的回收率达到95%左右,活化效果明显。溶液中的Pb^(2+)与白云母表面的K+发生置换作用,可使白云母ζ电位正向增大,进而强化油酸根等离子在白云母表面局部正电区的静电吸附作用,还可与溶液中的油酸根等离子反应生成油酸铅沉淀于白云母表面。此外,Pb^(2+)还可破坏白云母表面的水化层,使白云母表面暴露的Al和Si数目增多并提高其与油酸根的反应几率,最终使白云母的可浮性得到明显改善。

A study has been taken on to discuss Pb2＋ how to affect flotation behavior of muscovite in sodium oleate system, and the activation mechanism of Pb2＋ on muscovite was detected by means of flotation solution chemical, Zeta potential, IR and XPS spectra etc. The result showed that muscovite can be activated significantly when the amount of Pb2＋ was 9.06× 10.5 mol/L and sodium oleate was 9.20× 10.4 mol/L in pH=9, then the muscovite recovery rate can reach about 95.00%. That Pb2＋ in solution can replace K＋ on muscovite surface and leads ζ potential of muscovite to increase positively, which can intensify adsorption of oleic ions on muscovite surface in local positive charge by electrostatic adsorption and generate hydrophobic lead oleate which precipitate on muscovite surface. Furthermore, Pb2＋ can increase amount and reaction probability of reactive Al and Si on muscovite surface with oleic acid ions by destroying hydration layer of muscovite surface. So, muscovite floatability can be significantly improved.