For all dry grinding applications, cement production is certainly the most important. The estimate for the world energy consumption for cement production is 18.7 TWh which is approximately 0.02% of total world energy consumption per year. The world consumption of cement was about 1.72 billion tones in 2002 and it is increasing at about 1% per annum.
For most of the twentieth century, the dry grinding circuits for the production of finished cement from cement clinker consist of two-compartment tube mills and the air separators. It is not uncommon to produce the cement in an open circuit. Advances in cement grinding technology is slow and these advances are limited to more developed countries.Approximately 95% of the feed to the cement grinding circuit are clinker and the rest of the feed are “additives” which includes grinding aids. The quality of cement is measured by the surface area or the Blane index. The unit of the Blane index is m2/kg, and this index is determined by the Blane air permeability test. The surface area of the cement powder depends on size distribution of cement particles; smaller particles have larger surface area. If the particle size distribution is known, the Blane index can be successfully predicted
To optimise cement grinding, standard Bond grinding calculations can be used as well as modelling and simulation techniques based on population balance model (PBM). Mill power draw prediction can be carried out using Morrell’s power model for tumbling mills