The use of natural clay-carbonate gypsum in the production of sulfate-containing cements
The purpose of the article is to study the raw materials located in the deposits of Kyrgyzstan and used in the production of sulfate-containing cements. The article aims to identify features of the technological process of clinker formation. An analysis of deposits of gypsum raw materials in Kyrgyzstan was carried out. For the most common raw materials of limestones, their chemical and mineralogical composition was studied using the chemical, derivatographic and X-ray methods. By calculating raw mixtures, a charge was produced for obtaining sulfate-containing cement from limestone of the Tashkumyr deposit, local loams and clay-carbonate gypsum. The temperature regime of the clinker formation of sulfate-containing cements using local clay-carbonate gypsum awas studied. The article analyzes an effect of high temperatures on clay-carbonate gypsum whose chemical and mineralogical composition decreases the decarbonization temperature and causes the partial decomposition of CaSO<sub>4</sub> and the early formation of primary clinker minerals. The use of gypsum rock with a high content of carbonates and clay impurities as a sulfate component in the preparation of sulfoclinkers helps to reduce the decomposition temperature of calcium carbonate and sulfate during burning. The data on the intensification of clinker formation are presented. They depend on the composition of charge components and the burning temperature, which correspond to the low-power technology. The technology can save energy, reduce CO<sub>2</sub> emissions and improve the environmental safety.