I am making studies for cement plant and would like to make a following question? Is possible to control the weight in the ball mill (cement or raw mill plus balls) in order to save energy? My view point is if you have any chamber unbalanced in ball mill, the motor drive can be working in a forced way and spent much more energy than the necessary? Is possible to use the balls to correct that balance, because today we have in the cement plant a different weight in each chamber?

The weight of grinding balls in the mill and the power drawn by the mill main motor are directly proportional to one another. Therefore it is possible to reduce the power drawn by the mill by reducing the ball charge. However, this will then result in the output of the mill falling due to less grinding balls being present to grind the clinker and generate surface area. As with all these things there is an optimum ball charge and output which corresponds to the lowest unit energy consumption.

Do you have an idea of each point decreased in the standard deviation of the kiln feed and how it affects to the specific heat consumption? (for example:40 kj/kg of clinker for every additional 0.1 by which the standard deviation is raised in the usual range).

The effect of kiln feed standard deviation on unit energy consumption is complex and is likely to vary from kiln to kiln. For a precalciner kiln each one per cent increase in the standard deviation of the kiln feed lime saturation factor you might expect an increase in the energy consumption by 150 kJ/kg clinker. However, this relationship is unlikely to be linear and will vary around that figure from kiln to kiln.