捕收剂CTAB对一水硬铝石与高岭石的浮选差异及其分子动力学模拟

为了研究季铵盐类捕收剂对铝土矿反浮选的影响，以十二胺（DDA）为参照捕收剂，考察了十六烷基三甲基溴化铵（CTAB）对一水硬铝石和高岭石浮选回收率的影响，并通过FTIR分析、Zeta电位检测、吸 附量测定以及分子动力学模拟对作用机理进行了系统的分析。浮选试验结果表明，CTAB浮选分离效果优于DDA，在pH=4、CTAB浓度为2×10-4 mol/L时，纯矿物浮选试验一水硬铝石和高岭石浮选回收率相差51.70个百分 点，人工混合矿试验获得了Al2O3品位71.73%、回收率71.26%、SiO2含量9.43%的精矿，铝硅比A/S达到7.60。机理分析结果表明，捕收剂CTAB在一水硬铝石和高岭石表面均有吸附，在高岭石表面的吸附量大于在一水硬 铝石表面的吸附量，且均为物理吸附；分子动力学模拟计算结果表明捕收剂CTAB与高岭石总相互作用能为与一水硬铝石总相互作用能的2.29倍，因此CTAB分子优先吸附于高岭石的表面，具有较高的选择性，有利于反 浮选的进行。

Flotation Difference between Diaspore and Kaolinite with Collector CTAB and Its Molecular Dynamics Simulation

In order to study the effect of quaternary ammonium collectors on the reverse flotation of bauxite， the effects of cetyl trimethylammonium bromide （CTAB） on the flotation recovery of diasphalite and kaolinite were investigated using dodecyl amine （DDA） as reference collector.The mechanism of action was systematically analyzed by FTIR analysis， Zeta potential detection， adsorption capacity measurement and molecular dynamics simulation.The flotation test results showed that CTAB showed the better flotation separation effect compared with DDA. Under the condition of pH of 4 and CTAB concentration of 2×10-4 mol/L， the flotation recovery rate difference of diaspore and kaolinite in the flotation test of pure minerals is up to 51.70 percentage.A concentrate with Al2O3 grade of 71.73%， recovery rate of 71.26% and SiO2 contents of 9.43% was obtained by artificial ore mixing test. The Al/Si ratio reached to 7.60.The results of mechanism analysis showed that the collector CTAB adsorbs on both diaspore and kaolinite， and the adsorption amount on the surface of kaolinite is greater than that on the surface of diaspore， which both are physical adsorption.The results of molecular dynamics simulation showed that the total interaction energy between collector CTAB and kaolinite is 2.29 times that of collector CTAB on diaspore. Therefore， CTAB molecules are adsorbed on the surface of kaolinite firstly， which has high selectivity and is beneficial to reverse flotation.