A novel method for the desulfurization of medium–high sulfur coking coal

•The desulfurization performances of medium–high sulfur coking coal via combined methods of flotation and oxidation were compared creatively.•The desulfurization mechanism of medium–high sulfur coking coal was analyzed by XPS, SEM, MD simulation, etc in detail.•After combined treatment of flotation and H2O2 oxidation, inorganic sulfur is almost completely removed and its desulfurization performance is perfect.