Preparation of high purity magnesium by vacuum gasification-directional condensation technology

Abstract

As the lightest structural metallic material, magnesium (Mg) is expected to be widely used in many fields to instead of steel and aluminum. However, there are still too many kinds of impurities in Mg ingot which will be transformed to Mg products and damage their performance obviously. In this paper, by analyzing of the source and existence form of the impurities in Mg ingot and calculating the optimal removal temperature, the volatilization and condensation, migration and enrichment processes of different elements in purification process were clarified. Based on the theoretical research, a vacuum gasification-directional condensation technology and a vacuum tubular furnace were proposed, which can remove most impurities in Mg ingot. The key impurities (such as Fe, Co, Ni, Cu) and difficult to remove impurities (such as K, Na, Zn) are all removed effectively, high purity Mg more than 99.999% can be collect in the high temperature condensation region.