ABSTRACT
In order to increase the possibility of the utilization of coal fired power plant bottom ashes, beneficiation of unburned carbon was conducted. Flotation technique was used for this study. Before flotation experiments, samples were dry sieved and found that an important decrease in carbon content can be obtained using a 0.150 mm screen. At this size 49.88% of the sample was retained on the screen with 5.62% carbon content. This fraction can be used as a cement additive without any further processing. In the flotation experiments particle size distribution, collector and frother type were tested as variables. At optimum conditions, the carbon content of the concentrate increased from 7.88% to 41.65% at a carbon recovery of 68.51%. This fraction can be blended back into the coal feed to the power plant boilers. It was concluded that a further enhancement of the unburned carbon content in the products could be obtained by incorporating a cleaner stage in flotation.
