Abstract: The coke fines or charcoal fines are mixed with a liquid binding agent at an elevated temperature in a mixing chamber sealed from an attached mold and are then abruptly rushed into the mold after opening the disclosure to the mixing chamber and causing a vacuum to form in the mold. This results in an implosion action. Thereafter the mold is again sealed against the mixing chamber and the excess binding agent is removed by suction from the mold. The mold is provided at its inner surface with ridges causing lines of thinned cross section to form in the mass of coke or coal fines. The mass is then poured into an adjoining collecting vessel and is simultaneously caused to break up into individual lump pieces along the said thin cross sectional lines.