阴阳离子捕收剂在长石与石英表面的吸附特性

Adsorption characteristics of feldspar and quartz in anion-cation collector

采用单矿物浮选、ζ-电位和芘荧光探针,研究阳离子捕收剂十二胺(DDA)和阴离子捕收剂十二烷基磺酸钠(SDS)在长石和石英表面的吸附特性。单矿物浮选结果表明:pH=2.0时,相同浓度的单一或混合捕收剂溶液中长石的表面疏水性要强于石英的表面疏水性,混合捕收剂中矿物表面疏水性比单一捕收剂中的强。ζ-电位测定结果表明:在阴/阳离子单一捕收剂中长石和石英ζ-电位分别向负方向和正方向移动;阴阳离子混合捕收剂摩尔比接近1:1时,pH在2.0、2.5和9.0时长石和石英各自ζ-电位相差不大。芘荧光探针分析结果表明:pH=2.0时,捕收剂在低浓度时通过静电作用零星吸附于矿物表面,矿物表面极性与捕收剂浓度呈负相关,当矿物表面形成胶束后,单一捕收剂溶液中矿物表面极性有所增强,而混合捕收剂溶液中矿物表面极性继续降低;在相同条件下的混合捕收剂溶液中矿物表面的疏水性比单一捕收剂强,且在矿物表面形成胶束浓度要比单一捕收剂低;整体而言,相同浓度条件下单一和混合捕收剂溶液中长石表面疏水性比石英的强。

The adsorption characteristics of feldspar and quartz monomineral using dodecyl amine （DDA, cationic collector） and sodium dodecyl sulfonate （ SDS, anionic collector） as collector have been studied through pure minerals flotation, zeta potential and pyrene fluorescence. The results of pure minerals flotation under condition of pH=2.0 show that the hydrophobicity of feldspar is stronger than that of quartz in both single and anion-cation collector at the same concentration, and mixed collector makes them have stronger hydrophobicity than single collector. The zeta potential tests indicate that the potentiodynamic of mineral surface integrally shifts to positive direction in cationic collector, while it moves to negative direction in anionic collector. When the molar ratio of the anion-cation collector close to 1：1, the mineral potentiodynamic has no obvious difference to itself in solution of pH 2.0, 2.5 and 9.0. The pyrene fluorescence results under condition of pH=2.0 show that there is a negative correlation between polarity of mineral surface and dosage of collector in low concentration when using single collector and the layer formed in such a manner is sporadic. The polarity of mineral surface begins to increase after the micelle formed in solution of single collector, while the polarity of mineral continues to decrease in mixed collector. At the same condition, compared with single collector the polarity of mineral surface is stronger and the dosage of forming micelle concentration is much lower in anion-cation collector. In a whole, the polarity of quartz is stronger than feldspar in single and anion-cation collector at the same concentration.