Силікаткальцієві легковагі вироби, що отримані прямим твердофазовим синтезом з сировинних матеріалів України

Abstract

The thesis for a candidate’s degree of technical science on the speciality 05.17.11 – technology of hard-melting nonmetallic materials. – National Technical University "Kharkiv Polytechnic Institute", Kharkiv, 2015. The thesis is devoted to the development of calciumsilicate lightweight products technology, obtained by direct solid phase synthesis of raw materials Ukraine. The ration-al composition and technological parameters has been established, which provide calciumsilicate lightweight products with the apparent density 500 – 1000 kg/m³ and compressive strength limit 1,6–6,0 MPa. Is determined that high yield psevdowollastonite (up to 92 vol.%) formed by the use of combined lime contains material, consisting of chalk and gypsum at a ratio of 3: 1 in terms of CaO. Done thermodynamic analysis and the processes of phase formation during heat treatment in the composition of samples, including chalk, gypsum hemihydrate and quartz and pure calcium oxide and silicon with nonstoichiometrically ratio oxides CaO: SiO₂ (0,9) for the formation of wollastonite are investigated. It was established that the formation psevdowollastonite in a mixture of raw materials flows through the formation of intermediate compounds – larnite and β-wollastonite. Is determined that test samples of lightweight products characterized by a microporous structure. The products recommended for application at temperatures up to 1300 and 1250 °C. It is shown that the immutability the phase composition calciumsilicate lightweight products and exclusion of volume changes at polymorphic transformations wollastonite in psevdowollastonite during their service in the thermal aggregates is ensured by directed synthesis psevdowollastonite in products during their heat treatment. It was established that the thermal conductivity of test samples with microporous structure in the ~ 1,2–2,5 times less compared to macroporous chamotte lightweight products. Is de-termined that the developed products resistant to molten aluminum, and it is expedient recommended instead materials containing asbestos. Calciumsilicate lightweight products technology put into production in PJSC "The URIR named after A. S. Berezhnoy".