Effect of pores on the flotation of low-rank coal: An experiment and simulation study

Low rank coal contains a large number of pores and cracks which have an adverse influence on its flotation behavior. Effects of pores on the hydration layer and flotation behavior of low-rank coal were studied by molecular dynamics method and experiments in this paper. A specific surface area/pore analyzer was employed to determine the pore structure. Pore distribution analysis indicated that the pores in the low-rank coal are mainly micropores. Pore volume and average pore diameter in low-rank coal can be reduced by pore compression pretreatment. Coal-bubble attachment experiments were conducted to study the effect of pores on the effect of pores on particle bubble adhesion process. Results showed that coal particles with less pores were more likely to adhere to the surface of the bubble. And a probable mechanism for the effect of pores on the adhesion of coal particles to bubbles was proposed. Molecular dynamics simulation results revealed that the pores on the surface of low-rank coal reduce the mobility of water molecules and form a more stable hydration layer. Flotation results indicated that reducing the pore content in low-rank coal could reduce the collector dosage in flotation process and improve the flotation behavior of low-rank coal.