Recycling of waste plastic combustion soot and diesel oil mixing to prepare a new collector to improve the performance of low-rank coal flotation

Clean utilization of soot pollution and low-rank coal has received extensive attention worldwide. In this study, soot from plastic combustion was mixed with diesel oil as a new collector (SPC-DO) to enhance the low-rank coal flotation. The flotation results showed that SPC-DO improved the flotation of low-rank coal more effectively than diesel oil, with a higher yield of fine coal and lower ash content. In addition, the results of the scanning electron microscope, contact angle, X-ray photoelectron spectrometer, and Fourier transform infrared spectroscopy measurements showed that the soot from plastic combustion has superhydrophobicity, and the oxygen-containing functional groups on its surface can interact with the hydroxyl groups on the low-rank coal surface to form hydrogen bonds, which in turn cover the hydrophilic sites. When applying SPC-DO as the collector, the soot from plastic combustion not only increased the hydrophobic sites on the LRC surface but also enhanced the adsorption effect of diesel oil on the low-rank coal surface.