中文摘要：

用简化的＂布斯自由能函数＂对真空条件下用碳一步还原菱镁矿反应进行热力学分析,得到真空条件下碳酸镁分解和还原反应的起始温度。将菱镁矿和煤混合制团,进行一步还原炼镁试验。结果表明,在真空20Pa下温度600℃,30m in后碳酸镁基本分解完全,温度至1200℃,MgO被还原,冷凝得到条状金属镁,镁条表面纯度达93%,内部纯度可达99.5%以上。

英文摘要：

The process for extracting Mg directly from magnesite by carbothermic reduction under vacuum was thermodynamically analyzed using simplified Gibbs free-energy functions,and the critical temperature of the magnesite decomposition and MgO carbothermic reduction was calculated under vacuum condition.Some experiments for Mg reduction directly from magnesite by carbothermic reduction had been done.It showed that under 20Pa condition,the magnesite was almost completely decomposed at 600℃ after holding 30min,and the reduction reaction began around 1200℃,the fringe crystal of Mg was obtained.The purity of the fringe crystal may reach 93% on the surface,and more than 99.5% inside.