真空蒸馏分离铝镁合金的研究

首先采用MIVM计算了Al-Mg合金组元的活度,平均相对偏差和平均绝对偏差分别小于±2.231%、±0.035,表明采用MIVM计算Al-Mg合金组元的活度是可靠的。在此基础上,结合气-液平衡(VLE)理论,计算了Al-Mg合金体系的气-液平衡,并绘制了VLE相图,结果表明：蒸馏过程中铝、镁分别在液相和气相富集,二者能实现较好分离。开展了Al-Mg合金真空蒸馏实验,获得了VLE实验数据,并考察了蒸馏温度、保温时间对镁挥发的影响。结果表明：VLE计算值与实验值吻合,表明本研究建立的VLE计算模型是可靠的。另外,在蒸馏温度1373K、系统压强10~15Pa、保温时间120min条件下,镁的挥发率高达99.98%,直收率达到98.65%；残余物中Mg含量降至0.0017%。本研究为真空蒸馏回收铝镁合金废料奠定了理论及实践基础。

Study on separation of aluminum-magnesium alloy by vacuum distillation

First, MIVM is used to calculate the activity of Al-Mg alloy components. The average relative deviation and average absolute deviation are less than ±2.231% and ±0.035, respectively, indicating that the calculation of the activity of Al-Mg alloy components by MIVM is reliable. On this basis, combined with the gas-liquid equilibrium (VLE) theory, the gas-liquid equilibrium of the Al-Mg alloy system is calculated, and the VLE phase diagram is drawn. The results show that aluminum and magnesium are in the liquid and gas phases during the distillation process. Enrichment, the two can achieve better separation. Carried out Al-Mg alloy vacuum distillation experiment, obtained VLE experimental data, and investigated the influence of distillation temperature and holding time on magnesium volatilization. The results show that the calculated value of VLE is consistent with the experimental value, indicating that the VLE calculation model established in this study is reliable. In addition, under the conditions of distillation temperature of 1373K, system pressure of 10~15Pa, and holding time of 120min, the volatilization rate of magnesium is as high as 99.98%, and the direct yield rate reaches 98.65%; the Mg content in the residue drops to 0.0017%. This research lays a theoretical and practical foundation for the recovery of aluminum-magnesium alloy waste by vacuum distillation.