【摘要】 以白云石为原料,以铝粉为还原剂在真空条件下提取金属镁,研究影响还原工艺的因素。结果表明,温度、时间和压样成型压力对还原反应的影响顺序为温度>成型压力>时间,还原反应受扩散步骤控制,金属镁蒸气的蒸气压对反应的进行起主要作用。最佳还原工艺条件为还原温度1300℃、反应时间1h、成型压力300MPa,镁还原率为9299%。真空度对结晶镁的形态产生影响,真空度高于2×104Pa时,结晶镁形态为树枝状或针状,真空度低于35×104Pa时,形成块状金属镁。更多还原

【Abstract】 The magnesium is prepared from dolomite by aluminothermic process,and the influence factors of vacuum aluminothermic reduction are investigated.The results show that the prime factor is the reaction temperature,the next is pelletizing pressure,and the last is reaction time.The reduction is controlled by the diffusing step,the vapor pressure of magnesium plays a key role in the reaction.The optimal condition of reduction is temperature 1300℃,reduction time 1h,and the pelletizing pressure 300MPa.At this condition,the recovery of magnesium can reach 92.99%.The pattern of the crystallographic magnesium is influenced by the vacuum degree,when vacuum degree is higher than 2 × 104Pa,the dendritical or acicular magnesium is produced,while the vacuum degree is lower than 3.5 × 104Pa,the lumpish magnesium is obtained.更多还原