LAUSR

ABSTRACT A flotation study was conducted to evaluate the separation of coal in the presence of quartz and clay minerals. The interaction energies between coal and quartz, kaolinite, and montmorillonite were analyzed via the Extended Derjaguin-Landau-Verwey-Overbeek (EDLVO) theory. Also, the quartz, kaolinite and montmorillonite coatings were explored using SEM technique. Energy barriers were calculated to exist between coal and quartz, kaolinite, and montmorillonite preventing the change in interaction energy and followed the order: coal-quartz#coal-kaolinite#coal-montmorillonite. Using an SEM technique on the surface topography of coal, it was shown that the energy barrier between coal and montmorillonite rather than quartz and kaolinite was broken by the impeller rotation of 1800 r/min resulting in montmorillonite coating on the coarse coal surface. The coal cumulative yield for a flotation time 5 min was found to decline 2.94%, 5.74% and 47.99% in the presence of quartz, kaolinite, and montmorillonite, respectively, compared to that of only coal.