Application and Mechanism of Mixed Anionic/Cationic Collectors on Reverse Flotation of Hematite

Abstract

In order to enhance the reverse flotation effect of hematite, dodecyl trimethyl ammonium chloride (DTAC) and a mixed anionic/cationic collector of DTAC and tall oil were selected for flotation studies on quartz and hematite. Surface tension tests, FT-IR, XPS analysis, and molecular dynamics (MD) simulations were also conducted in order to investigate the interaction mechanism of the mixed collector on the quartz surface. The results revealed that, at a natural pH (approximately 7.0) and 298 K, and with a dosage of 20 mg/L for the mixed collector (mDTAC:mtall oil = 3:1) and 4 mg/L for causticized starch, the recovery rates of quartz and hematite were 94.67% and 8.69%, respectively. Compared to the use of a single DTAC, the mixed DTAC/tail oil collector enhanced the flotation effect under constant variables. Additionally, a comparison of temperature and surface tension for monomineral flotation and artificially mixed ore flotation tests showed that the mixed collector was less influenced by temperature, compared to the single DTAC, and exhibited good resistance and more effective separation of quartz and hematite at lower temperatures. The analysis of FT-IR, XPS, and MD simulations revealed that the single DTAC collector primarily adsorbed onto quartz through physical adsorption and hydrogen bonding, while the combination of tall oil and DTAC enhanced the adsorption of the collector on the quartz surface.