J. Donėlienė “The hydrothermal synthesis, properties and application of functional xCaO·y(Al2O3, SiO2)·zH2O compounds” doctoral thesis defence

Author, Institution: Jolanta Donėlienė, Kaunas University of Technology,

Science area, field of science: Technological Sciences, Chemical Engineering – 05T

Summary of doctoral thesis: Summary

Scientific supervisor:
Doc. Dr. Anatolijus Eisinas (2014–2017, Kaunas University of Technology, Technological Sciences, Chemical Engineering, 05T);
Prof. Dr. Danutė Vaičiukynienė (2010–2014, Kaunas University of Technology, Technological Sciences, Civil Engineering, 02T).

Scientific Advisor:
Prof. Dr. Danutė Vaičiukynienė (2014–2017 m., Kaunas University of Technology, Technological Sciences, Chemical Engineering, 05T).

Dissertation Defence Board of Chemical Engineering Science Field:
Prof. Dr. Raimundas Šiaučiūnas (Kaunas University of Technology, Technological Sciences, Chemical Engineering, 05T) – chairman;
Dr. Valentin Antonovič (Vilnius Gediminas Technical University, Technological Sciences, Materials Engineering, 08T);
Prof. Dr. Rimvydas Kaminskas (Kaunas University of Technology, Technological Sciences, Chemical Engineering, 05T);
Prof. Dr. Saulius Kitrys (Kaunas University of Technology, Technological Sciences, Chemical Engineering, 05T);
Prof. Dr. Martin-Tchingnabé Palou (Slovak University of Technology, Technological Sciences, Materials Engineering, 08T).

The doctoral dissertation is available on the internet and at the library of Kaunas University of Technology (K. Donelaičio str. 20, Kaunas).

Annotation:

Hydrothermal synthesis of xCaO·y(Al₂O₃, SiO₂)·zH₂O compounds in the CaO-Al₂O₃-SiO₂-H₂O system is a complex process. The formation of compounds in this system are determined by the duration of isothermal treatment, temperature and composition of the initial mixture. Therefore, it is important to examine the influence of synthesis conditions on the formation and properties of functional xCaO·y(Al₂O₃, SiO₂)·zH₂O compounds.
In this work it was determined that hydrogranates which usually form during hydrothermal synthesis in CaO, SiO₂ and Al₂O₃ suspensions may not be obtained in this system, and only calcium hydroaluminates and calcium hydroalumosilicates may dominate in the products. It was revealed that the synthetic calcium hydroalumosilicate additive changes the hydration of cement samples and accelerates the curing process: it shortens the induction period, stimulates the hydration of C₃S and increases the total amount of heat released. It was determined that synthetic mayenite additive, which stabilizes the natural CaO chemosorbent in the cyclic CO₂ adsorption/desorption process, can be obtained at 350°C temperature by burning hydrothermally treated calcium hydroalumosilicate. According to the obtained results, conclusions, recommendations and the rational application areas of the above mentioned synthetic calcium hydroalumosilicate additive were proposed