Investigation on the flotation of a mixed collector and its mechanism for enhancing low-rank coal flotation: Effect of micro adsorption and its interaction with gangue particle

The flotation effect of the association formed by dodecyl trimethyl ammonium bromide (DTAB) and dodecyl alcohol polyoxyethylene ether sodium sulfate (AES), and nonpolar kerosene mixed collectors on low-rank coal (LRC) was investigated. The results show that the combustible matter recovery was significantly improved compared with a single kerosene from 49.88% to 74.97% when the the mixed collector was used, while concentrate ash content decreased from 9.76% to 8.57% simultaneously. The utilization of the mixed collector not only enhanced the surface hydrophobicity of organic particles but also facilitated the intercoalescence among them, thereby reducing the ash content of concentrate during flotation. The molecular dynamics simulation (MDS) results show that the effect of the mixed collector on the surface of LRC is mainly the electrostatic interaction and hydrogen bonding between the collector molecules and the surface molecules of LRC, which makes the polar molecules in the collector closely adsorbed on the surface of LRC.