Study Of Physicochemical Property On Hydrating Processes Of Partially Hydrated Magnesium Chloride

The purpose of this paper is to provide theoretical parameter for the engineering of the dehydration of bischofite using hydrogen chloride as the protective gas. According to the characteristic of the engineering, the water content and the hydrogen chloride content in the rare gas must be determined and the protective gas should be recycled. Many Physicochemical parameters were obtained through the tentative efforts in the experimentation, which the water was absorbed by partially hydrated magnesium chloride and the protective gas was recycled in the engineering of dehydration of bischofite.1 A method to determine the water content and the hydrogen chloride content in the rear gas from the dehydration of bischofite using hydrogen chloride as the protective gas was be established.The water was absorbed by phosphorus pentoxide and weighted directly. The hydrogen chloride gas was absorbed by sodium hydroxide solution. The chloride ion is titrated with hydrargyrum nitrate standard solution. The systemic error was eliminated by using correction factor. So, the method to determine the water content and the hydrogen chloride content in the rear gas from the dehydration of bischofite using hydrogen chloride as the protective atmosphere was be established.2 Standard partially hydrated magnesium chloride was obtained in laboratory.By TG-DTG, DTA to MgCl₂ · 6H₂O, the suitable temperature to preparation partially hydrated magnesium chloride was obtained. And the production, which was determined by the analyses of chemical titration and Kaer-feixiu titration, was coincident with the standard of crystallogeny. The result was confirmed by X-ray diffraction.3 The thermodynamic calculation of water vapor pressure in hydrating processes of partially hydrated magnesium chloride.The mechanism of hydrating processes of partially hydrated magnesium chloride was discussed and predicted in this paper. The balance pressure of water vapor during hydrating processes of partially magnesium chloride was calculated.4 The study on kinetics to hydrating processes of partially hydrated magnesium chloride was calculation.By special apparatus, the temperature and the humidity were controlled. Under the condition of suitable temperature and humidity, the datum, apparent activation energy, apparent preexponential factor and so on, of kinetics in hydrating processes of partially hydrated magnesium chloride was obtained by the methods of X-ray diffraction and chemical analysis.It is showed, from the kinetic date of hydration processes of partially hydrated magnesium chloride in this paper, that it is kinetic possibility to use partially hydrated magnesium chloride as a absorbance to clean the water, which from the dehydration of bischofite using hydrogen chloride as the protective gas, and the protective gas was recycled in the engineering of dehydration of bischofite...