К вопросу о характере связи воды в гидроксиде кальция

Abstract

Проанализированы процессы получения гидроксида кальция двумя способами. Изучены физико-химические свойства получаемого продукта, определен температурный режим на последних стадиях процесса. Рекомендован режим сушки для удаления физически связанной воды в интервале температур 105−120 °С. Доказано, что в гидроксиде кальция, полученном сушкой пасты после ее выделения из известкового молока, кроме физически связанной воды, имеется адсорбционно-связанная вода по типу Ca(OH)₂·nН₂О, удаление которой происходит в интервале температур 120−360 °С.The processes of preparation of the calcium hydroxide in two ways: slaking excess water to the lime milk, separating the calcium hydroxide paste with subsequent drying; slaked lime to calcium hydroxide, bypassing the stage of milk of lime. The physicochemical properties of the resulting product is defined temperature range in the last stages of the process. When playing process in the laboratory revealed that drying in this temperature range does not allow to obtain a product with a high content of Ca(OH)₂, although the amount of undesirable impurities is minimized. It was suggested a different nature due to water Ca(OH)₂ prepared in various ways. In order to test hypotheses, experiments were conducted. Was obtained by the activation energy is very close to the value of heat decomposition of Ca(OH)₂ is equal to 125 kJ/mole. IR calcium hydroxide, confirmed the formation of hydrate forms other than Са(ОН)₂, for example, Са(ОН)м·nН₂О. The results of these studies showed that calcium hydroxide obtained by drying the paste after its discharge from the milk of lime but physically bound water, there is an adsorption-bound water type Са(ОН)₂·nН₂О, removal takes place in the temperature range 120–360 °C.