Development and Evaluation of Clay Binders in Fine Coal Cleaning by Froth Flotation

Abstract It has been long known that the clay particles in coal severely impede the froth flotation process. This is mainly due to its tiny size « IfYm in most cases) or huge specific surface area that results in the adsorption of large amounts of reagents such as frother or collector that is added to the pulp to enhance flotation separation. In addition, tiny clay particles are easily carried into the clean coal product through a mechanism referred to as hydraulic entrainment, which further reduces the sharpness of the flotation separation. Use of clay binders is a promising approach for enhancing coal flotation performance by agglomerating clay particles to enlarge their apparent size, reduce their surface area and reagent adsorption, minimize the non-selective hydraulic entrainment. The main goal of the proposed project is to develop and evaluate selective clay binders to enhance fine coal froth flotation process for cleaner coal product and 5-10% higher energy recovery. Use of clay binders is also expected to double or triple clean coal dewatering rate due to reduced clay content and significantly increase waste particle settling rate in the thickener and waste pond as a result of increased particle size.