• Comminution is the oldest mechanical unit operation for size reduction of solid materials and an important step in many processes where raw materials are converted into intermediate or final products.

  • The purposes of comminution are to reduce the size, to increase the surface area, and to free the useful materials from their matrices, and recently it has been involved in modification of the surface of solids, preparation of the composite materials, and recycling of useful components from industrial wastes.

  • The energy efficiency of comminution is very low, and the energy required for comminution increases with a decrease in feed or produced particle size.