Theoretical Capacity of Roll crusher = ( * N * D * W * S * ρ) tons/hr N = Number of revolutions of the rolls, RPM. D = Diameter of the roll, inches = 8" W = Width of a roll, inches = 5" ρ = Density of the crushed ore, gram/cm3 GRINDING: Grinding is the last stage in the process of comminution. In this stage the particles are reduced