Aiming for a tighter raw material specification may not necessarily be the best option for a cement plant looking to improve the economics or quality of its final product. Drawing up such a specification is a balancing act where changes in one raw material can lead to further changes to other parts of the raw mix.
At most cement plants where the author has had some responsibility for the raw materials there are regular discussions on the specification of the raw materials supplied to the plant. Usually these are the result of a request to tighten up the specifications so that consistency of the raw feed can be maintained.
Under stable circumstances the request appears not just reasonable but essential – the more consistent the raw materials the better the quality through the whole process.1
