The invention regards to a device for comminuting ore and/or slag, which comprises an ore feed unit for feeding ore to be comminuted to a first comminuting means. The first comminuting means being composed of at least two comminuting elements that can be moved relative to each other, which elements form at least one comminuting space for the ore to be comminuted with each other such that, by a relative movement in the form of a rotation around the rotational axis of at least one of the two comminuting elements. The ore to be comminuted is pulverised in that one or more accelerating elements, in particular protrusions, are provided on at least one of the comminuting elements. The accelerating elements being arranged in particular on the end face of one of the two comminuting elements and accelerating and comminuting the ore to be comminuted by the rotation of one of the two comminuting elements. Between the two comminuting elements and/or in at least one of the two comminuting elements, an intermediate space is provided through which during the rotation the pulverised ore can be conveyed away outwards from the centre of the rotation and from the two comminuting elements. An outlet unit for outletting ore comminuted by the first comminuting means is provided which is connected to the intermediate space. The outlet unit is connected with a separating means, by means of which the comminuted ore is separated into two portions. A first portion of the comminuted ore comprises a particle size, which is essentially larger as a predefined particle size of a second portion of comminuted ore. The first portion of the comminuted ore is guided to the first comminuting means or to a second comminuting means and the second portion of the comminuted ore is guided to a floation means.