Experimental and molecular dynamics simulation study on the enhancement of low rank coal flotation by mixed collector

• Published in: Fuel (Guildford) 2020-04, Vol.266, p.117046, Article 117046
• Main Authors: Zhang, Lei, Sun, Xiaole, Li, Bao, Xie, Zhixuan, Guo, Jianying, Liu, Shengyu
• Format: Article
• Language: English
• Subjects: Adsorption; Dodecane; Emulsification; Flammability; Flotation; Hydrogen bonding; Low rank coal; Mixed collector; Molecular dynamics; Molecular dynamics simulation; Simulation
• ISSN: 0016-2361; 1873-7153
• DOI: 10.1016/j.fuel.2020.117046

[Display omitted] •Flotation response of LRC is improved by mixed collector markedly.•The adsorption characteristics of mixed collector on LRC were investigated by MD.•Adsorption of mixed collector on LRC is driven by electrostatic and hydrogen bonding. Flotation collectors have a significant effect on the flotation performance and efficiency of fine low rank coal (LRC) particles. In this study, a mixed collector consisting of a nonpolar collector (dodecane) and a polar collector (C12EO4, tetraethylene glycol monododecyl ether) was used to improve the flotation performance of LRC. The results show that flotation behavior can be enhanced with the addition of C12EO4 in dodecane. The yield, combustible matter recovery, and flotation efficiency index increase with a larger volume ratio of C12EO4 in the mixed collector. A molecular dynamics simulation (MD) approach was applied to explore the microscopic strengthening mechanism of the mixed collector. The simulation demonstrated that the interaction strength and spreading ability of the mixed collector on the LRC surface increased due to electrostatic attraction and hydrogen bonding between the mixed collector and the LRC surface (as indicated by interaction energy and contact surface area), thereby enhancing flotation performance of the LRC. The effect of C12EO4 on the emulsification and dispersibility of dodecane is also discussed.