取代基对十二烷基阳离子表面活性剂捕收铝硅酸盐矿物的影响

Effect of substitution in dodecyl-cationic collectors on flotation of aluminosilicates

以4种连有不同取代基的阳离子表面活性剂为铝硅酸盐矿物捕收剂,研究各药剂对铝硅矿物的浮选能力及浮选特点。运用密度泛函理论(DFT)B3lyp/6-31G(d)方法,对4种捕收剂的阳离子结构进行优化,并计算原子电荷分布等量化参数和几何结构参数。研究结果表明:甲基的取代可增强阳离子的静电作用能力,同时,削弱它与矿物表面之间的氢键作用;苄基的取代不仅增强药剂的静电效应,而且增加氢键的结合能力;理论分析结果与浮选试验结果一致,季铵盐的浮选能力较伯胺与叔胺的强,连有苄基的季铵盐对铝硅酸盐矿物的捕收能力最强,且受pH值影响小。

Flotation behaviors of gangue aluminosilicates was studied with four dodecyl-cationic collectors, which have an N-containing polar group with different substitutions. Density functional theory （DFT） with B3lyp method at 6-31G（d） level was also employed for optimizing the geometries of collector cations and calculating the atomic charges. The results show that methyl group strengthens the electrostatic attractions, but reduces the H-bonds effect, while benzyl group can make both electrostatic and H-bond effects strong. The theoretical results are identical with the results of the collectors flotation tests. Collecting ability of the quaternary amine salts is better than that of dodecylamine and dodecyl bimethyl amine. The quaternary amine salt containing benzyl group performs best, and it is little affected by pH value. Substitution of N-containing polar group in amine collectors can impact the aluminosulicate minerals flotation.