COMMINUTION THEORY AND PLANT PRACTICE
which is free to move inside the mill, thus comminuting the ore particles. The grinding medium may be steel rods, or balls, hard rock, or, in some cases, the ore itself. In the grinding process, particles between 5 and 250 nun are reduced in size to between 10 and 300 pin. All ores have an economic optimum mesh of grind which will depend on many