Abstract: This invention relates to a method and apparatus for grinding with two toothed plates operating face to face, one of which plates is fixed and the other of which is rotated by a shaft, with an axial supply of material to be ground and peripheral evacuation of the ground products. Chambers are provided for circulating of cooling water in contact both with the fixed plate and with the rotatable plate. At an intermediate radial point of the plates, a liquid nitrogen injector which enables reduction of the temperature of the product during treatment and making the grinding zone inert is fitted. The invention is applied to the grinding of rubber.