The separation of magnesite and quartz using flotation is complicated because of their hydrophilicity. In this study, N, N-Dimethyloctadecylamine (NDOA) was used as a collector for the first time to selective enhance the magnesite and quartz surfaces' hydrophobicity and efficiently separate magnesite from quartz. The micro-flotation study showed that NDOA had a selective-collection influence on quartz and that magnesite separation from quartz could be accomplished at pH 5.0 and 60 mg/L NDOA. In contact-angle tests, NDOA showed selectively enhancement in the contact angle of quartz, leading to enhanced surface hydrophobicity of the quartz, but not magnesite. As revealed by field emission scanning electron microscopy (FESEM) with an energy dispersive X-ray spectrometer (EDS) detecting, NDOA predominantly adsorbed onto quartz surface and transformed its surface from smooth to rough and oily, rather than magnesite. NDOA adsorption on the quartz surface through hydrogen bonding and electrostatic interaction was identified through FTIR spectroscopy. According to X-ray photoelectron spectroscopy (XPS), the preferential adsorption of NDOA on the surface of quartz is due to NDOA's interaction with the O sites of quartz. On the basis of these findings, a potential model for the flotation separation process was suggested.

由于菱镁矿和石英的亲水性，使用浮选分离菱镁矿和石英是复杂的。本研究首次采用N,N-二甲基十八胺（NDOA）作为捕收剂，选择性增强菱镁矿和石英表面的疏水性，有效分离菱镁矿和石英。微浮选研究表明，NDOA 对石英具有选择性捕收作用，在 pH 5.0 和 60 mg/L NDOA 条件下，菱镁矿与石英的分离可以实现。在接触角测试中，NDOA 显示出选择性地提高了石英的接触角，导致石英的表面疏水性增强，但菱镁矿没有。正如具有能量色散 X 射线光谱仪 (EDS) 检测的场发射扫描电子显微镜 (FESEM) 所揭示的，NDOA 主要吸附在石英表面并将其表面从光滑转变为粗糙和油性，而不是菱镁矿。通过 FTIR 光谱确定石英表面通过氢键和静电相互作用吸附 NDOA。根据 X 射线光电子能谱 (XPS)，NDOA 在石英表面的优先吸附是由于 NDOA 与石英的 O 位点的相互作用。在这些发现的基础上，提出了浮选分离过程的潜在模型。NDOA 在石英表面的优先吸附是由于 NDOA 与石英的 O 位点的相互作用。在这些发现的基础上，提出了浮选分离过程的潜在模型。NDOA 在石英表面的优先吸附是由于 NDOA 与石英的 O 位点的相互作用。在这些发现的基础上，提出了浮选分离过程的潜在模型。