Preparation of anhydrous magnesium chloride in a gas-solid reaction with ammonium carnallite

• 来源期刊: 中国高等学校学术文摘·化学
• 关键词: ammonium carnallite gas-solid reaction anhydrous magnesium chloride
• 年，卷（期）: 2006,（4）
• 页码范围: 384-388
• 页数: 5页
• 语种: 英文

摘要

Dehydrated ammonium carnallite was synthesized with bischofite from salt lake and ammonium chloride solution in a 1:1 molar ratio of MgCl2:NH4Cl,dehydrated at 160℃ for about 4 h.The yield was above 85%.The product was then mixed with solid-state ammonium chloride with a 1:4 mass ratio for the further dehydration at 410℃.The decomposition of NH4Cl made a pressure of NH3 at 30.5 kPa to prevent the hydrolysis of ammonium carnallite.The anhydration of magnesium chloride was achieved at 700℃.The results showed that anhydrous magnesium chloride contains magnesium oxide in an amount that was less than 0.1% by weight.XRD pattern and SEM micrograph showed a good dispersion of ammonium carnallite and anhydrous magnesium chloride crystals with well-distributed big grains,just enough to meet the need for the production of magnesium metal in the electrolysis process.