Abstract: A method and apparatus for grinding brittle stock such as cement clinker to form finished cement, passing the grinding stock through a first roller press having pressure and nip capabilities to do product bed comminution which is unique in self particle destruction causing incipient cracks in the inside of the product particles which are delivered from the press in agglomerations or scabs, the agglomerated scabs are delivered to a second roller press of larger capacity, which also does product bed comminution, de-agglomerating the scabs after the second roller press, classifying the de-agglomerated product and recirculating the coarse fraction back to the second roller press and possibly also to the intake of the first roller press.