A method and device for gas-phase magnesium purification based on nickel-based filter material

Abstract

The invention provides a method for purifying magnesium in the vapor phase based on a nickel-based filter material. The method uses a nickel-based filter material to filter magnesium vapor. Under a certain temperature and vacuum degree, the nickel material does not react with the magnesium vapor on the one hand. It will not bring new impurities to the system; on the other hand, the nickel material has a special affinity with the impurities Al and Mn in the magnesium vapor, and can form a stable solid solution; at the same time, the nickel material can also be used as some impurities in the magnesium vapor The nucleation site lowers the nucleation energy barrier and enables some impurities to be deposited in advance to achieve removal. The method provided by the invention can be applied to industrialized large-scale gas-phase magnesium purification, while improving the production efficiency by an order of magnitude, the Mn content in magnesium is reduced to below 10ppm, the Al content is reduced to below 10ppm, and the Si content is below 20ppm. Non-metallic impurity elements such as F, Cl, S, etc. improve product purity, and the purity of the obtained magnesium is above 99.99%.

Description

technical field [0001] The invention belongs to the technical field of metal magnesium purification, in particular to a method and device for gas-phase magnesium purification based on a nickel-based filter material. Background technique [0002] Magnesium alloy has the advantages of low density, strong damping and shock absorption, excellent electromagnetic shielding performance and relatively low recycling cost. Therefore, it is regarded as "21st century green environmental protection engineering structural material" and an important strategic material. At present, in the field of magnesium purification, there are chronic problems such as low overall product purity (only 99.90%), many types of impurity elements (mainly containing Mn, Al, Ca, Si, Fe, Ni, etc.), and large content fluctuations. These chronic problems seriously deteriorate the performance of magnesium alloys, which in turn leads to its practical application far less than expected. [0003] There are two common...

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Problems solved by technology

However, in order to obtain higher purity, the distillation method is generally carried out under vacuum conditions and at an evaporation temperature close to the melting point of Mg (650-700 ° C), so its preparation efficiency is low; the purity of crystalline magnesium in different temperature zones is different, generally only at a suitable temperature The crystalline magnesium is high-purity magnesium, so its high-purity magnesium yield is low; in order to obtain ultra-high-purity magnesium (99.999%-99.9999%), multiple distillations are required, so the cost is very high

Based on the above reasons, the vacuum distillation method cannot meet the needs of industrialized large-scale production.

[0005] In addition, the method of purifying magnesium in the prior art also has the method of using filter material to assist impurity removal by vapor deposition, but generally the filter material uses stainless steel fiber or the method of combining stainless steel fiber with copper fiber, and stainless steel is not suitable for the environment where the vapor pressure of magnesium is too high. Working conditions, suitable for low heating temperature - low temperature sublimation conditions, so the efficiency of magnesium purification is low, and the output of high-purity magnesium is extremely low

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