Analysis of the grinding behaviour of
various Portland cement clinkers
Summary: Relationships between composition and microstructure of nine industrial Portland cement clinkers from Brazil and their behavior during size reduction are analyzed. Detailed analyzes of composition and microstructure have been conducted, whereas their comminution behavior was analyzed using single-particle breakage and Bond ball mill grindability tests. In addition, the porosity has been estimated. It is demonstrated that the behavior of the clinkers varies significantly as a function of fineness of grind, which should translate into very distinct performances at the different stages in grinding. Initial grindability has been found to be determined by porosity, which has progressively less influence as grinding progresses, leading to no apparent influence in finish grinding. Intermediate grindability was found to be predominantly influenced by the alite content, whereas finish grindability is influenced by the aluminate and aluminoferrite contents in the clinker.
1 Introduction
Chemical and physical properties of cement clinker are influenced by many factors including chemical, physical and mineralogical characteristics of the raw materials, the burning and cooling processes, the fuel used and the capacity of the kiln. Grindability and the energy consumption in clinker grinding are influenced by a number of factors as well. If it is defined as the rate of production of fine material for a given energy expenditure, then it is reasonably well accepted that grindability increases with porosity and alite content (3CaO · SiO2 or C3S) [1, 2] and decreases...
