A process for removing an agglomerate of accumulated materials including ash concentrate which collects within the first heavy phase withdrawal conduit of a coal deashing system employing solvent at elevated temperatures and pressures near the critical temperature of the solvent. A carrier fluid is introduced into the first heavy phase withdrawal conduit simultaneously with or after pressure reduction of the heavy phase under conditions such that a turbulent flow profile is developed within the withdrawal conduit which results in the removal of at least a substantial portion of any accumulated materials within the withdrawal conduit.