Selective collection and differential adsorption of pentaethoxylated laurylamine for the flotation recovery of magnesite from quartz

Differential sorption behaviors of collectors at mineral/water interface play a crucial role in mineral flotation by selectively strengthening the hydrophobicity of the target minerals. To efficiently recover of magnesite from quartz, pentaethoxylated laurylamine (PEOLA) was introduced as a low-cost and high-selectivity collector to replace conventional collector laurylamine (LA). The collection performance and separation effectiveness of PEOLA were assessed by conducting flotation experiments. Furthermore, a series of surface detection experiments involving surface adsorption tests, zeta-potential characterization and FT-IR analysis, were conducted to uncover the selective collection mechanism of PEOLA toward quartz and magnesite. Flotation results indicated that compared with LA, PEOLA exhibited much better flotation selectivity for quartz against magnesite and could recover magnesite more effectively from quartz through reverse flotation. Therefore, PEOLA accomplished the efficient separation of magnesite and quartz, wherein 96.50% of magnesite was recovered and 95.50% of quartz was removed. Surface analyses demonstrated that a large quantity of PEOLA could be adsorbed onto quartz instead of magnesite, which promoted the efficient collection of quartz using PEOLA. Furthermore, the intense adsorption of PEOLA onto quartz was driven by the combination of electrostatic attraction and hydrogen bonding interactions. Thus, PEOLA can be considered as a high-performance and low-cost collector for efficiently recovering magnesite from quartz.