A contribution to the understanding of the processes taking place during the burning of cement clinker

For the formation of calcium silicates during clinker burning it is postulated that the SiO2 migrates to the calcined particles of limestone or marl in the kiln feed during the formation of C2S. The C3S is then formed in two stages, the majority being-produced by solid-state reactions within the particles. The formation of alite is then completed by transfers between the particles, assisted by a melt phase. All processes take place on and in individual particles during which there is hardly any change in size. The sizes of the resulting C2S and C3S crystals are therefore essentially determined by the particle size of the raw meal.