Producing Pure Magnesium Through Silicothermic Under the Atmospheric Pressure

The majority of pure magnesium produced worldwide is made by using silicothermic method (Pidgeon process). However, the Pidgeon process suffers poor efficiency, low industrial concentration, and intermittent production. The main reason is that Pidgeon process requires to keep the reaction chamber in a vacuum state during the entire reduction process. By analyzing the thermodynamic reaction principle, we reveal that it is the low magnesium partial pressure instead of vacuum that is necessary for the silicothermic process. Based on this understanding, we develop a new technique that can produce pure magnesium under the atmospheric pressure by using silicothermic method. Flowing argon is used to carry away the magnesium vapor around the reactants, which reduces the local magnesium partial pressure. The magnesium production efficiency reaches 82.36% that is comparable to the widely used Pidgeon method, and high purity of magnesium with 99.97 wt% after melting is produced directly. The industrialized application of this exciting technique is expected to help the silicothermic to realize high efficiency, automated, and continuous production while at the same time completely change the poor production conditions, and reduce energy consumption and pollution.