Improving flotation performance of intruded coal using heavy oil as a collector

This investigation is to compare the flotation performance of intruded coal using heavy oil and kerosene as the collector, respectively. The effect of impeller speed during the conditioning process is also discussed. Fourier transform infrared (FTIR) spectroscopy was used to indicate the properties of heavy oil, kerosene, and intruded coal surface. Scanning electron microscopy (SEM) was used to indicate the surface morphology of intruded coal. Induction time measurement was used to indicate the induction time between coal surface and bubble. FTIR results show that the intruded coal surface is not hydrophobic and heavy oil contains more unsaturated hydrocarbon and oxygen containing groups than kerosene. Therefore, heavy oil can adsorb on intruded coal surface more effectively as unsaturated hydrocarbon and oxygen containing groups can bond with coal surface through hydrogen bonding and π-bonding. SEM results indicate the surface of intruded coal can be covered by many ultrafine coal particles after the conditioning with heavy oil and kerosene. More fines cover intruded coal surface after heavy oil conditioning, compared to kerosene conditioning. The flotation recovery of intruded coal using heavy oil as a collector is higher than that using kerosene. With the increasing impeller speed, the flotation recovery of intruded coal is firstly increased and then has a little decrease. Exorbitant conditioning may have a negative effect in the adsorption of fine coal particles on the pores and surfaces of intruded coal