2012 Volume 66 Issue 1 Pages 217-222
Cement industry is one of the energy-intensive industries. Though Japanese cement industry has achieved top-class energy efficiency in the world, the development of the further energy saving technology is needed from the view point of global environmental protection such as the reduction of carbon dioxide and fossil fuel consumption. In this study, we investigated the potential of the burning temperature reduction by adjusting major mineral composition of clinker determined by Bogue equation. First, we prepared nineteen kinds of clinkers by changing major mineral composition of clinker. As a result of free lime and porosity, it became clear that C4AF contributed the most to sintering clinker among the four major elements. In summary, the contribution order to clinker burnability is that C4AF＞C3A＞C2S＞C3S. It seemed that compressive strength decreased in case C4AF was increased, but we found that the decrease of strength development was minimized by reducing C2S instead of increasing C4AF. On the basis of these results, we investigated the clinker burnability and cement strength in detail by using industrial raw materials, in case of increasing C4AF and decrease C2S instead. As a result of free limes and porosity, it became clear that by increasing C4AF 7％, the sintering degree of clinker was equal even if it was burned at 1,350 degrees, which was 100 degrees lower than the actual case. As a result of compressive strength, it also became clear that by increasing C4AF 7～9％, the strength development of cement was kept even if the clinker was burned at 1,350 degrees. From the above-mentioned result, we found the possibility that the burning temperature of clinker could be lowered 100 degrees by adjusting major mineral composition.
