Oil agglomeration is an effective technique for recovering and reducing the ash of coal fines. In this study, the effects of some parameters that markedly influence the effectiveness of selective oil agglomeration, such as solids concentration, amount of agglomeration oil and agglomeration time, on the recovery of agglomerate and the ash and the pyritic sulphur content of the agglomerates were investigated. In order to delineate the relation between the formation rate of coal-oil agglomerates and the removal of ash and pyritic sulphur, the rates of agglomeration for Balkaya and Askale lignites were also calculated by using experimental data. It was found that the success of the process in terms of both recovery and selectivity for lignites was highly dependent on the parameters and control of the agglomeration rate.