Magnesium Alloy Scrap Vacuum Gasification—Directional Condensation to Purify Magnesium

Abstract

Magnesium alloys, known as a “21st-century green engineering material”, are widely used in many fields, including during the production and consumption of magnesium alloys die-casting products such as AZ91D, AM50, and AM60B. In addition, a large amount of waste is generated, which not only pollutes the environment but also wastes secondary resources. Hereby, we reported the vacuum gasification—directional condensation method, calculated the vapor pressure separation coefficient parameters, and drew the gas-liquid phase equilibrium diagram depending on the distillation temperature, condensation temperature, and system pressure for the magnesium volatilization process. The results showed that under the following conditions (distillation temperature: 1073 K, system pressure: 100 Pa, condensation temperature: 873 K, and condensation duration: 30 min), the magnesium volatilization yield could approach 93.76%, and the purity of magnesium could reach 99.98%. This research is a good theoretical and practical basis for the recovery of magnesium alloy waste using the vacuum gasification method.