Термодинамический анализ реакций в системе Si – Ca(OH)₂ – H₂O
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Дата
2015
ORCID
DOI
Науковий ступінь
Рівень дисертації
Шифр та назва спеціальності
Рада захисту
Установа захисту
Науковий керівник
Члени комітету
Видавець
НТУ "ХПИ"
Анотація
В статье приведены результаты термодинамического анализа реакций в системе Si – Ca(OH)₂ – H₂O, характерной в технологии производства ячеистых газобетонов. Показана возможность осуществления направленного синтеза минералогического состава продуктов гидратации в изучаемой системе. В качестве одного из продуктов реакции гидратации рассматривались такие гидросиликаты кальция, как тоберморит, фошагит, ксонотлит, гиролит, окенит и гиллебрандит, имеющие наиболее согласованные исходные термодинамические характеристики. Анализ полученных результатов расчетов свидетельствует о том, что наименьшим значениям изменения энергии Гиббса реакций образования гидросиликатов соответствуют стехиометрические соотношения исходных компонентов.
It was presented the results thermodynamic analysis of the reactions in system Si – Ca(OH)₂ – H₂O, that is typical for technology of cellular gas concrete. The possibility of realization of directional synthesis mineralogical composition of hydration product has been revealed in the investigated system. As one of hydration products were considered calcium hydrosilicate as tobermorite, foshagite, xonotlite, girollite, okenite and hillebrandite. They have possessed the most consistent initial thermodynamic characteristics. Analysis of calculation results achieved that the smallest value of Gibbs energy change of formation reactions hydrosilicates are corresponding to the stoichiometric ratio of the initial components. Nature of Gibbs energy change from temperature is ambiguous and depends on the ratio of calcium hydroxide and metal silicon in the hydrated system. Analysis of research results displays that the least stable with increasing pH of solution is girolite, and most sustainable is hillebrandite, solubility occurs almost at the equilibrium pH of saturated solution of calcium hydroxide. Under normal conditions of hydration and lime surplus all previously formed low-basic hydrous directly or sequentially transformed into high-basic: okenite in girolite, girolite in tobermorite, xonotlite in tobermorite, xonotlite in foshagite, foshagite in hillebrandite. Thermodynamic probability of passing of such reactions has been confirmed by negative values of Gibbs energy reactions.
It was presented the results thermodynamic analysis of the reactions in system Si – Ca(OH)₂ – H₂O, that is typical for technology of cellular gas concrete. The possibility of realization of directional synthesis mineralogical composition of hydration product has been revealed in the investigated system. As one of hydration products were considered calcium hydrosilicate as tobermorite, foshagite, xonotlite, girollite, okenite and hillebrandite. They have possessed the most consistent initial thermodynamic characteristics. Analysis of calculation results achieved that the smallest value of Gibbs energy change of formation reactions hydrosilicates are corresponding to the stoichiometric ratio of the initial components. Nature of Gibbs energy change from temperature is ambiguous and depends on the ratio of calcium hydroxide and metal silicon in the hydrated system. Analysis of research results displays that the least stable with increasing pH of solution is girolite, and most sustainable is hillebrandite, solubility occurs almost at the equilibrium pH of saturated solution of calcium hydroxide. Under normal conditions of hydration and lime surplus all previously formed low-basic hydrous directly or sequentially transformed into high-basic: okenite in girolite, girolite in tobermorite, xonotlite in tobermorite, xonotlite in foshagite, foshagite in hillebrandite. Thermodynamic probability of passing of such reactions has been confirmed by negative values of Gibbs energy reactions.
Опис
Ключові слова
газобетон, кремний металлический, известь, гидратация, минералообразование, энергия Гиббса, concrete, metal silicon, lime, hydration, mineralization, Gibbs energy
Бібліографічний опис
Термодинамический анализ реакций в системе Si – Ca(OH)₂ – H₂O / А. А. Салей [и др.] // Вестник Нац. техн. ун-та "ХПИ" : сб. науч. тр. Темат. вып. : Химия, химическая технология и экология. – Харьков : НТУ "ХПИ". – 2015. – № 30 (1139). – С. 85-91.