A study of the intergrinding of clinker and limestone

In this paper the intergrinding of clinker and limestone is studied and the fineness of each material is estimated. Clinker and limestone, which are the main constituents of Portland-limestone cements, have different grindabilities and the cement properties are affected by the particle size distribution of each component. Four clinkerllimestone mixtures, containing 10, 20, 30 and 40% limestone respectively, were ground to 4 different degrees of fineness, and a sedimentation method was used in order to collect samples of different particle size. In each size fraction the limestone content was determined and finally the particle size distribution of clinker and limestone was computed. It is concluded that the presence of the easily ground limestone leads to a wider particle size distribution of the mixture. In addition, limestone is concentrated in the fine fractions (<8μm) while the clinker is concentrated in the coarser fractions. Finally, it is concluded that a limestone content over 30% obstructs the grinding of both clinker and limestone.