铵光卤石气固反应法制备无水氯化镁

铵光卤石气固反应法制备无水氯化镁;ouig

Preparation of Anhydrous Magnesium Chloride via Gas-solid Reaction of Ammonium Carnallite

Ammonium carnallite was synthesized with a >85% yield by a process in which a mixture of (hydrated) magnesium chloride from the salt lake and ammonium chloride solution at a 11 molar ratio was (dehydrated) to some extent at 160 for about 4 h. Dehydrated ammonium carnallite and solid ammonium (chloride) were mixed at a 14 mass ratio, and the ammonium chloride in the mixture was decomposed into NH_3 and HCl, in which the pressure of NH_3 reached 30.5 kPa and dehydrated ammonium carnallite was dehydrated by NH_3 at 410 , and finally the anhydrous magnesium chloride was calcined at 700 . The result shows that (magnesium) oxide in the anhydrous magnesium chloride was less than 0.1% by mass. The XRD pattern and SEM micrograph demonstrate that the ammonium carnallite and the anhydrous magnesium chloride crystals were respectively (homogeneous), the grains of them big and well-distributed. The anhydrous magnesium (chloride) thus produced can be used for the production of magnesium metal through electrolysis.