A preliminary investigation of microbubble flotation of fine coal

Abstract

Although froth flotation is generally recognized as the most viable means of cleaning fine coal, a loss in recovery rate and selectivity is encountered when attempting to apply the process to clean ultrafine coals. In this work, batch flotation tests were conducted on several Appalachian coals using microbubbles in a cylindro-conical flotation column. Results indicate that this technique shows improvements over the conventional technique using larger bubbles, when the coal is ultrafine. The improvement in recovery rate with the microbubbles is due to improved hydrodynamic conditions which are more conducive to bubble/particle collision, while the improvement in selectivity is due to the absence of turbulent wakes.