Energy saving cement production by grain size optimisation of the raw meal

Resumo

The production of cement clinker is an energy consuming process. At about 50% of the energy costs are associated with grinding and milling of the raw meal, that normally is in the range 100% ‹ 200 µm with 90% ‹ 90 µm. Question: is it possible to use coarser components of the raw meal without reducing the clinker quality? With synthetic raw meals of various grain sizes the clinker formation was studied at static (1100 - 1450°C) and dynamic conditions (heating microscope). A routine to adjust the grain size of the components for industrial raw meals is developed . The fine fraction ‹ 90 µm should mainly contain the siliceous and argileous components, whereas the calcitic component can be milled separately to a grain size between 200-500 µm, resulting in lower milling costs. Considering the technical and economical realizability the relation fine/coarse should be roughly 1:1. Milling costs can be reduced significantly, that in addition leads to the preservation of natural energy resources.