Grinding comminution efficiency

CHARACTERISTICS OF COMMINUTED PRODUCTS. The objective of crushing and grinding is to produce small particles from larger ones. Smaller particles are desired either because of their large surface or because of their shape, size, and number. One measure of the efficiency of the operation is based on the energy required to create new surface, for as shown in Chap. 28, the surface area of a unit mass of particles increases greatly as the particle size is reduced. 

The term particle (or grain) size refers to the structural make-up of such substances as granulates, powders, dusts, granular mixes, and suspensions. Knowledge of the particle size, in conjunction with the comminution process, determines such details as grinding efficiency and ultimate product fineness. To establish particle sizes and their distribution within powdered systems, the user can have recourse to a number of different measuring processes designed to indicate, with appropriate particle definition, details of the probable equivalent diameter of a particle. 

In a mineral process plant, the process of comminution is one of the least efficient and highest consumers of power. A number of equations are used to define the process of dry grinding. These are described by Elliott (1991). 

---