Investigation of collector mixtures on the flotation dynamics of low-rank coal

Here, Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), flotation experiments, and low-rank coal (LRC) particle-bubble attachment measurements (using the particle-bubble attachment index [PBAI]) were employed to explore the effects of collector mixtures on the flotation kinetics of LRC particles. At a flotation dosage of 3.0 kg/t, the greatest flotation recovery (62.51%) for a single collector was achieved using triethanolamine oleic acid monoester (TOAM), compared with using kerosene or 2-ethylhexanol. At the same dosage, the maximum flotation recovery increased to 84.25% when using a mixture of TOAM with kerosene. However, when the collector dosage was more than 2.5 kg/t, the fitting result of the flotation rate constant obtained by mixing TOAM with kerosene was larger than those obtained by mixing 2-ethylhexanol with either kerosene or TOAM. Furthermore, when the attachment time exceeded 100 ms, the greatest PBAI value (0.84) was obtained when mixing kerosene with TOAM, rather than when mixing 2-ethylhexanol with kerosene or TOAM. Thus, this study presented an improved mixture of TOAM and kerosene that can aid the flotation performance of LRC and could be regarded as potential application for LRC flotation industrial.