Recycling of thermal power plant bottom ashes

Abstract

Beneficiation of unburned carbon was conducted in order to increase the possibility of the recycling of coal fired power plant bottom ashes. Two stage flotation techniques were used for this study. In the flotation experiments collector, dispersant and frother amount, pulp density and flotation temperature were tested as variables. After first stage flotation experiments, at optimum conditions, the carbon content of the concentrate increased from 14.25 % to 51.54 % at a carbon recovery of 54.54%. At the same conditions, the carbon content was reduced down to 5.36 % at a weight yield of over 80 % in the tailings fraction. This fraction meets the industrial demand and can be utilized as a cement additive. After the cleaner stage flotation experiment the carbon content of the product is enhanced to 64.81 % with a 48.17 % carbon recovery.