Composite Cements with Mineral Additives of Intrusive and Metamorphic Rocks of Central Aldan (Yakutia)

Abstract

The creation of new compositions with mineral additives requires fundamental research of the chemical activity of mineral additives. As an active mineral additive used waste production of chromdiopside and phlogopite –dunite and diopside Aldan region (Yakutia). The use of overburden reduces the cost of production of building materials and improves the environmental situation in the region. The obtained dependence of the strength developed in cements, their composition, preparation of the raw mix, modes of curing and keeping maturing. For the first time, using a set of technological approaches including pre-annealing, mechanical activation and autoclave synthesis, a high-strength composite cement with additives of magnesium silicates exceeding the strength of Portland cement by 56.8% was obtained. In our previous experiments, the introduction of up to 40% diopside in Portland cement did not increase the strength of the cement stone due to the chemical inertness of the additive. Magnesium chloride - MgCl2 was used for mixing in order to activate hydration. It is shown that the high rate of formation of the solid phase during the closure with magnesium chloride leads to the development of stresses and strains leading to a decrease in strength in the later stages of hardening. The optimal technological approach is water mixing and autoclave synthesis. Possible consumers can be cement plants, enterprises for the production of building materials, representatives of medium and small businesses, as well as enterprises of the mining industry interested in the disposal of waste production.