In this study, bottom ash from the Tuncbilek power plant has been characterized by X-ray fluorescence, X-ray diffraction, and infrared analysis. The bottom ash sample is potentially of class C type and has unburned carbon. The unburned carbon was separated from the bottom ash in a laboratory flotation cell. In the flotation experiment, sodium silicate (as a potential dispersant and depressant), butanol (promoter), kerosene oil (collector), and pine oil (frother) were used and the optimization of these flotation reagents were done through statistical modeling using a full two-level factorial design in order to evaluate the main and interaction effects of variables in flotation of unburned carbon; the evaluation of the results was done by Yates' notation. Test results showed that a product with 45.41% combustible grade at 40.0% recovery and 94.86% ash rejection was obtained at 1.98 g/kg sodium silicate, 1.38 g/kg promoter, 4.95 g/kg collector, and 2.41 g/kg frother.