Abstract The hydrolysis of magnesium chloride hexahydrate and the countermeasures against hydrolysis were investigated. X-ray diffraction, TG-DSC analysis, and chemical analysis were employed to characterize the hydrolysis process, and then the hydrolysis reactions occurred at different temperatures were determined. After that, the combination of inhibition of hydrolysis and conversion of hydrolysate was adopted to cope with the different hydrolysis reactions. The hydrolysis process of MgCl2·6H2O includes the hydrolysis of dehydrated magnesium chloride below 300 °C with MgOHCl·xH2O as hydrolysate and the hydrolysis of anhydrous MgCl2 over 400 °C with MgO as hydrolysate. The inhibition of hydrolysis by forming dehydrated ammonium carnallite (below 300 °C) and the conversion of hydrolysate (above 400 °C) can effectively resolve the hydrolysis problem occurred at different stages. The dimension of the mixture of MgCl2·6H2O and NH4Cl influences the mass transfer and reaction process. When the ratio of height to diameter of the mixture was over 9:1, the magnesia content in anhydrous MgCl2 reached 0.1 wt.%.

中文翻译：

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MgCl2·6H2O抑制水解转化的脱水反应

摘要 研究了六水氯化镁的水解及水解对策。采用X射线衍射、TG-DSC分析和化学分析对水解过程进行表征，然后测定不同温度下发生的水解反应。之后，采用抑制水解和水解产物转化相结合的方式来应对不同的水解反应。MgCl2·6H2O的水解过程包括以MgOHCl·xH2O为水解产物在300℃以下水解无水氯化镁和以MgO为水解产物在400℃以上水解无水氯化镁。通过形成脱水铵光卤石（300℃以下）抑制水解和水解物转化（400℃以上）可以有效解决不同阶段发生的水解问题。MgCl2·6H2O和NH4Cl混合物的大小影响传质和反应过程。当混合物的高径比超过9:1时，无水MgCl2中氧化镁含量达到0.1wt.%。