Cement quality in thermochemical clinker activation

Abstract

Improving the quality of cement while reducing the energy costs of its production is one of the most important tasks of the cement industry. Cement properties are determined by the hydration activity of clinker minerals. In turn, the activity of clinker minerals is determined by the degree of disorderliness of the crystal cell. The disorder of the crystal cell depends on the chemical composition of minerals, the type and concentration of modifying additives. It also depends on the modes of clinker synthesis, both during firing and cooling. An effective way of activating clinker minerals is intensive firing of the components of the raw mixture. This method can be carried out by thermal activation of calcium oxide, as well as by bilateral introduction in different zones of the rotary kiln of polycomponent waste of chemical and metallurgical industries The composition and morphology of the main mineral of Portland cement clinker, alite, have been studied by methods of physical and chemical analysis. It was found that the crystals being formed are characterized by a nonstoichiometric composition. Their rapid growth is accompanied by intensive introduction of impurity elements into the crystal cell of the mineral. The hydration activity of clinkers of conventional and intensive firing has been determined. An increase in the rate of hydration of intensive firing clinkers has been established, which leads to an increase in the strength characteristics of cement by 7-10 MPa.