相同链长伯铵盐和季铵盐对云母表面润湿性的影响

胺类捕收剂通过吸附在云母表面而改变其亲水性,从而达到浮选的目的。当溶液浓度由1.00×10~(-5)mol/L增加到2.04×10~(-4)mol/L,捕收剂为十二胺时白云母表面接触角由46.71°增大到78.77°,而捕收剂为十二烷基三甲基溴化铵时的白云母表面接触角由25.79°增大到65.31°,说明相同浓度条件下十二胺能更好地改变白云母表面的亲水性,使之具有疏水性。原子力显微镜观察白云母表面捕收剂吸附图也表明,捕收剂浓度为2.04×10~(-4)mol/L,相比十二烷基三甲基溴化铵,白云母表面能吸附更多的十二铵离子。应用Materials Studio 6.1软件,采用PCFF_phyllosilicates分子力场,模拟研究白云母表面的水化作用的变化。结果表明因为伯铵盐能更稳定地吸附在白云母表面,其改善白云母表面亲水性的能力强于季铵盐。从理论和实践上解释了伯铵盐能更好地改变白云母表面的亲水性,使其具有一定的疏水性,从而达到浮选的目的。

The InfluenceSof Same Carbon chain length of Primary AmineSand Quaternary Amine on WettabilitySofSMuscoviteSSurface

Amine collector can alter the hydrophobicity of mica via the adsorption on mineral surface, thus separate the target mica from ores. When the concentration of dodecylamine solution increased from 1.00×10_-5mol/L to 2.04×10_-4mol/L, contact angle on muscovite surface increased from 46.71° to 78.77°, while it changed from 25.79° to 65.31° in the same concentration range for dodecyltrimethylammonium. Compared with dodecyltrimethylammonium bromide, dodecylamine renders a more efficient capacity to change the wettability of mica. Atomic force microscopy (AFM) results showed more dodecylamine molecules were adsorbed on the basal surface of mica than dodecyltrimethylammonium at the same concentration. Furthermore, molecular simulations of hydration phenomenon on muscovite were conducted in Materials Studio 6.1 by using PCFF_phyllosilicates molecular force field. In accordance with the experimental results, simulation results show that primary ammine possesses a better modification effect due to the stronger affinity between dodecylamine and mica than dodecyltrimethylammonium bromide.