Investigation on a novel mixed collector for carbon recovery from coal gasification fine slag: Experimental insight and macro molecular simulations

Abstract

The effectiveness of flotation for decarbonizing fine slag from coal gasification depends on the selection of appropriate collectors or surfactants. This study explored the synergistic effect of kerosene combined with cationic surfactants, including dodecyl trimethylammonium chloride, dodecylamine, and dodecylamine hydrochloride, on recovering residual carbonaceous material from coal gasification fine slag, using both MD and experimental simulations. The Scanning electron microscopy and X-ray spectroscopy revealed that the water molecules and oxygen-rich silicon glass beads dominated the slag surface, while the XPS analysis demonstrated that the functional groups containing oxygen on the residual carbon surface promote hydrogen bonding with water molecules in the flotation solution. The results suggested that the highest yield, along with optimal Loss on Ignition (LOI) and combustible recovery, was achieved at the 10⁻⁵ mol/L surfactant concentration. The MD simulations demonstrated that dodecylamine had the highest diffusion coefficient and adsorption capacity, explaining its superior interaction with residual carbon surfaces and its effectiveness in the decarbonization process. This approach contributed to the valorization and reuse of carbon generated by the waste of coal gasification fine slag.