中文摘要：

对真空碳热还原法炼镁过程中氧化镁的行为进行了热力学分析和动力学模拟,热力学分析表明,真空下CO量很少,被CO还原的MgO可以忽略。而MgO自身分解比较难。在此基础上,进行了分子动力学模拟研究,结果表明,高温对于MgO的结构影响并不明显,Mg-O键不会断裂生成Mg蒸气与氧气。此外Mg-O之间并无相互作用。对MgO在1723 K、50 Pa条件下加热过程的动力学模拟计算结果表明,高温并不会使Mg-O键自身发生断裂,MgO结构并未有明显变化。

英文摘要：

The reactions involving MgO,in Mg-smelting by vacuum carbothermic reduction,were mathematically modeled,theoretically calculated in thermodynamics,and numerically simulated in density functional theory（ DFT） with CASTEP module of Material Studio. The calculated results show that the reduction of MgO with CO can be neglected because few CO molecules exist,and that MgO cannot be easily decomposed into Mg and O_2 in vacuum. The impact of the temperature（ 1723 K） and pressure（ 50 Pa） on the bond breaking of MgO and formation of Mg vapor and O_2 was simulated via molecular dynamics calculation. The simulated results show that neither O_2-gas nor Mg-vapor form because the temperature of 1723 K fails to break the highly stable Mg-O bond. The two reactions,MgO（ s） ＋ CO（ g） = Mg（ g） ＋ CO_2（ g） and 2MgO（ s） = 2Mg（ g） ＋ O_2（ g）,were found to be absolutely impossible in vacuum carbothermic reduction.