The Lehmann Pre-refiner is equipped with a buffer on top, ready to take the complete batch of chocolate discharged from the mixer. First refining and calibrating of the crystal sugar particles is done by means of the two rolls, discharging the product further on towards the conveyor and to the five roll refiners downstream. High wear resistant rolls together with proven components on hydraulic controls drive technology and gap adjustment provide consistant and reliable production of pre-ground chocolate, ready for further refining.