Abstract: A treatment system for solid bulk materials such as limestone or mineral ore is provided having a belt conveyor configured for receiving the solid bulk material upon a transportation surface thereof and for displacing the material from a charging region to a discharging region according to a rectilinear path and a heating chamber, configured to receive a solar radiation conveyed by an external field of heliostats. A length portion of the transportation surface passes within or below the heating chamber so that thermal energy associated with the solar radiation is transferred to the bulk material by direct impingement or by reflection or re-irradiation by internal surfaces or walls of the heating chamber.