菱镁矿脱硅中分子结构特征对胺类捕收剂选择性捕收效应的影响研究

Effect of Amine Collectors with Different Structures on the Separation of Magnesite from Quartz

为研究胺类阳离子捕收剂结构特征对菱镁矿反浮选脱除石英效率的影响规律,通过浮选试验对比考察了十二胺、十六胺、十八胺、十六烷基三甲基氯化铵(HTAC)和十八烷基三甲基氯化铵(STAC)等5种不同结构的胺类捕收剂对菱镁矿和石英可浮性的影响。结果表明,不同条件下,菱镁矿与石英可浮性差异大小顺序为:HTAC体系>STAC体系>十二胺体系>十六胺体系>十八胺体系;且在矿浆pH值7.0、HTAC用量30 mg/L时,菱镁矿和石英的可浮性差异最大。Zeta电位、表面接触角和XPS检测得出,不同条件下菱镁矿与石英表面零电点正移量、接触角、结合强度和吸附量的差异顺序为:HTAC>STAC>十二胺>十六胺>十八胺。由此得出,随着碳原子数量的增加,伯胺(R—NH2)和季铵(R—N(CH3)3)阳离子捕收剂在菱镁矿脱硅中的效应逐渐降低;同等烷基条件下,带支链阳离子捕收剂在菱镁矿脱硅中的效应优于无支链阳离子捕收剂。

In order to study the influence of the structural characteristics of amine cationic collector on the efficiency of anti-flotation removal of quartz from magnesite,the effect of five amine collectors with different structures,such as dodecylamine,hexadecylamine,octadecylamine,hexadecyl trimethyl ammonium chloride(HTAC)and octadecyl trimethyl ammonium chloride(STAC),on the floatability of magnesite and quartz were investigated through flotation test.The results show that the order of floatability difference between magnesite and quartz was as follows:HTAC system>STAC system>dodecamine system>hexadecamine system>octamine system under different conditions,and the floatability of magnesite and quartz was quite different when the pulp pH value was 7.0 and the HTAC dosage was 30 mg/L.Zeta potential,contact angle and XPS detected that the order of difference between the positive shift of zero electric point,contact angle,bonding strength and adsorption capacity on the surface of magnesite and quartz under different conditions was as follows:HTAC>STAC>dodecamine>hexadecylamine>octamine.In summary,with the increased of the number of carbon atoms,the selective collection performance of primary amine(R-NH2)and quaternary ammonium(R-N(CH3)3)cationic collectors for magnesite and quartz gradually decreased,and the selective collection performance of branched cationic collectors was better than that of unbranched cationic collectors under the same alkyl conditions.