It is important to estimate the distribution of hydrophilic/hydrophobic sites on coal in a coal-cleaning process. The relationship between the distribution of hydrophilic/hydrophobic sites on coal and the carbonaceous materials recovery in a continuous column flotation was investigated. The amount of adsorbed methylene blue was determined to estimate the fraction of hydrophilic surface on coal surface. As a result, it turned out that the hydrophilic nature estimated by using methylene blue adsorption was closely related to the carbonaceous materials recovery.
