Study on feasibility of lignite flotation using shale oil based on results of experiments and molecular simulation

In order to explore the feasibility of making lignite flotation with shale oil as collector, the chemical composition of shale oil, and the effects of lignite flotation behavior and preconditioning of lignite with shale oil and kerosene on functional groups on coal surface, as well as the characteristics of molecular-level configuration of coal-oil-water system are investigated photoelectron sepectroscopic analysis and molecular simulation.Results of analysis and experiments show alkane and olefin are the main chemical components of shale oil, which are mostly in a long-chain form with a carbon number of 12-22; the shale oil can cover up the hydrophilic oxygen-containing functional groups on lignite surface, leading consequently to the increase of relative contents of C—C/C—H; and with the use of shale oil as collector at any concentration, the effect of flotation of lignite is noticeably better than the case of using kerosene.It is revealed that adsorption of shale oil can cover part of the voids on lignite surface, causing the reduction of roughness of lignite surface and restraining as a result the molecular diffusion of water.It proves that shale oil is a high-efficiency collector for lignite flotation.