The relationship between cement quality and separation cut size

Abstract

Cement is prepared by firing a mixture of raw materials, one of which is mainly composed of calcium carbonate and the other of aluminium silicate. The most familiar materials answering to this description are limestone and clay, both of which occur in nature in a great number of varieties. Marls, which are a mixture of clay and shales, are also common raw materials for cement. The production of cement is an energy-intensive process. The typical energy consumption of a modern cement plant is about 90-120 kWh per ton of produced cement. The service properties of cement such as workability and strength development are affected not only by the chemical and mineralogical composition but also to a great extent by the fineness and particle size distribution of the cement produced; in practice often only the strength development of cement is of primary interest. Yet the effect on workability is just as important. Moreover, the surface area and granulometric parameters may also directly or indirectly affect the frost resistance and other durability-related properties of concrete. There are process engineering options for controlling fineness and particle size distribution of the cement by changing the mode of operation of the mill and the separator. This paper describes a study of the relationship between cement strength and separation cut size (d50). The separation cut size (d50) of air separator products obtained by different days was ascertained by using particle size analysis. It was found that the cement fineness and separation cut size (d50) are very effective on the strength of cement.