Krakhmal Y. Сalciumsilicate lightweight products obtained by direct solid phase synthesis of raw materials Ukraine.

Object of study: the processes of phase- and structure formation in calciumsilicate lightweight products. Research objective: the development of calciumsilicate lightweight products technology obtained by direct solid phase synthesis of raw materials Ukraine. Methods of investigation: chemical, petrographic, X-ray diffraction, electron microscopic analysis methods and standardized methods for studies of the properties of refractory masses and lightweight products. Theoretical and practical results: compositions, a method for producing calciumsilicate lightweight products based on the use as the primary blowing agent of water, bonded in the structure of samples by means gypsum and removed by heat treatment, and technological parameters of obtaining products were developed. The developed technology of calciumsilicate lightweight products allows to obtain products with a microporous structure, a low thermal conductivity and high resistance to molten aluminum. Scientific novelty: it is determined that in the temperature interval 1220-1420 °C the reaction proceeds with the formation of wollastonite for the compositions with nonstoichiometrically (0,9) and stoichiometrically (1) the ratio of CaO: SiO2, containing chalk, gypsum hemihydrate, and quartz, as well as pure oxides calcium and silicon; it is established that the directed solid-phase synthesis psevdowollastonite (up to 92 vol.%) directly in the products from a mixture of chalk, gypsum and quartz with nonstoichiometrically ratio of CaO: SiO2 (0,9) is provided the use of combined lime contains material from a chalk and gypsum hemihydrate at a ratio of 3:1 in terms of CaO, flows through the formation of intermediate compounds (larnite and betta-wollastonite) and allows to obtain products with a stable phase composition and thermo mechanical characteristics during their service in the thermal aggregates. Degree of implementation: the developed technology is introduced in Ukraine in PJSC "The URIR named after A.S. Berezhnoy". Scope of application: thermal aggregates at temperatures up to 1300 ° C, in particular in contact with molten aluminum, in the metallurgical and mechanical engineering industries, the educational process.