A novel approach to the separation of macerals in inertinite-rich coal: Charged micro-nanobubble flotation

The classification and utilization of coal macerals have become a vital focus for the advancement of the modern coal chemical industry and mineral processing. Flotation is a well-established technique for large-scale mineral separation, but as for maceral separation, it is often limited by a low recovery rate and poor selectivity. This study investigates the utilization of charged micro-nanobubble (CMNB) flotation to separate the vitrinite from a typical low-ash and inertinite-rich coal in Xinjiang. Results show that CMNB flotation demonstrated notable index advantages over conventional flotation. Optimal flotation was achieved by the CMNBs produced from a 0.75 mM sodium dodecyl sulfate (SDS) solution, with a yield, concentrate vitrinite content, and vitrinite recovery of 49.58 %, 74.31 %, and 77.28 %, respectively. It was revealed that the CMNBs not only promoted the aggregation of vitrinite particles but also increased the adhesion of vitrinite particles and their aggregates to conventional flotation bubbles, resulting in enhanced flotation performance. [Display omitted] •Developed charged micro-nanobubble flotation-based separation of maceral.•Showed notable index advantages of CMNB flotation over conventional flotation.•Clarified mechanisms for charged micro-nanobubble enhancing maceral flotation.