Relative Basic Research On The Compound Alcohol-Ammonia Process Of Preparing Anhydrous Magnesium Chloride

Focusing on development and utilization of Salt Lake bischofite resource, the dissertation researched crystallization process of the ammoniation which is most crucial during the preparation of anhydrous magnesium chloride by ethylene glycol-ammonia process. Three sections were studied, including the solubility of ammonia in ethylene glycol, the ammoniation balance, and studies on conditions which influences the crystallization process of the ammoniation. Specific work and results are as follows.1. The solubility of ammonia in ethylene glycol were measured and the corresponding mathmatical model was established. Five temperature levels were considered, tha is303.15K,308.15K,313.15K,318.15K, and323.15K, and seven pressure levels,30KPa,40KPa,50Pa,60KPa,70KPa,80KPa,90KPa, so a total of35groups of solubility were accomplished. A thermodynamic model which based on the extended Raoult’s law and the extended Henry’s law, was proposed to describe the ammonia solubility under the experimental conditions.2. Based on the equilibrium of the ammoniation reaction, the following researchments were carried out.(1) The effect of temperature and pressure on the concentration of ammonia in the mother liquor was investigated, with the controlled tial of the solubility of ammonia in ethylene glycol;(2) The molar ratio of ammonia to magnesiun in the solid-phase products was studied to find out the condition intervols in which the reaction of the synthesis of hexammoniate magnesiun chloride happens. Simultaneously the boundary equation was arrived at;(3) Reaction Equilibrium Constants of the complete amination under different temperatures were caculated. Furthermore, Van’t Hoff equation was established by Parameter Estimation, and the values of the equation were associated with experimental data, and good results were achieved;(4) The concentration of magnesium chloride and ammonia in the mother liquor was accounted by the calculated values of the equilibrium constant, and the deviation from the experimental ones was analized too.3. Kilogram-grade amplification experiments were executed basing on the above work to determine the best process conditions. Therefore the influences of temperature, feed rate, residence time and the incubating process on the reactive crystallization were discussed.Three temperature levels (318.15K,313.1K and323.15K), four feed rates (5ml/min,10ml/min,15ml/min,20ml/min), and six residence time levels (75min,100min,125min,150min,200min,250min) were arranged.