Influência da cristalinidade e finura da sílica na estrutura da alita

Abstract

The sustainability today is, doubtlessly, the major concern and pursuit in cement industry all over the world. The gigantic step is necessary towards this aim depends not only on the technical knowledge and use of new technologies in the productive units, but it is also crucial deepening of the scientific knowledge, on the part of all the technical staff involved in the process. According to several studies, part of this pursuit is in the production of alite crystals increasingly smaller and with the maximization of the polymorphic relation M1/M3, which leads to the reduction of electric consumption in the grinding of cement and intensifies the reactivity of the C3S. The phenomenon of formation of the crystals of alite occur on the surface of the silic particles, and they affect their structure. To comprehend this effect, it is necessary to standardize the chemical and physical compositions of the raw mix, as well as their burning and cooling conditions. For this, the techniques of FRX, Lazer Granulometry, Light Optic Microscopy Transmitted and DRX with Rietveld refining are fundamental; and in this study revealed the influence of the dimension of the particles of silicon on the Free Lime and the dimension of the C3S, showing that this effect is due only to its dimension and pureness, and not to its crystallinity. On the other hand, the dimension of the particles of silica and their crystallinity showed much influence on the morphologic relation M1/M3 of the alite. On the other hand, the action known of the SO3 on the stabilization of the morphologic M1, was only observed for the crystalline silica and for crystals C3S coming from the quartz with medium dimension < 50 μm. The results showed that the combination of the dimension of the quartz and the % of SO3 of the clinker are paramount factors in the reduction of the medium dimension of the C3S and in the maximization of the morphologic relation M1/M3.