Influence of the particle size of components of the raw material mixture on the processes of clinker melt formation

Using coarsely ground slurries is one of the reserves to improve the performance indicators of cement production. Conventional division of the raw material mixture into a coarse and a fine part and analysis of physical and chemical processes that occur during heating of the fine (with particle sizes less than 0.08 mm) raw mixes at the Topkinsky (TTSZ) and Krasnoyarsk (KTSZ) cement plants, using the diagram of CaO- SiO2- Al2O3 system status, show that the fine part of raw mixtures containing 32-37% of CaCO3, the whole clay component and corrective additives, produce compositions forming the liquid phase of the clinker in an amount of 43-45% (wt.). In this case, in the TTSZ mixture CS, C2AS and CAS2 may be formed, and in the KTSZ mixtures - CS, C3S2, C2AS, which determine their high reactivity with respect to the lime contained in the coarse fractions of the raw mix with particle sizes 0.08-1.00 mm. The study of capillary impregnation of various limestone fractions with water shows that the velocity of the fluid in the coarse fractions is by an order of magnitude higher than in the fine fractions. It can be expected that a similar pattern will occur at the interaction of the clinker melt with the lime formed from coarse limestone fractions – when this lime interacts with the non-equilibrium melt, the rate of reactions producing clinker minerals will increase.

Author: V.A. Lotov, Y.G. Kozlovsky

Section: Science and production

Keywords: sludges, dispersion, roasting, melt capillary impregnation