Method for preparing refractory active metal or alloy

Abstract

This invention relates to a method for preparation of refractory active metals or alloys, which comprises the following steps: selecting CaCl2 or mixed salt electrolyte mainly including CaCl2 as flux, coining or perfusing refractory active metals to be block-shaped, sintering them to get sintered cake, compounding sintered cake and liquid of conductive cathode group and making them as cathode, making graphite or inert electrode as anode; making electrolyzation voltage no lower than academic decomposition voltage of melted salt, and making electrochemical reduction carryed out on cathode, but not forming compact sedimentary deposit to prevent the touch of compounds and electrolyte, controlling electrolyzation temperature at 500-1000 degrees, controlling the electrolyzation time according to 1-4 times theoretical electrical energy demand, making sure inert atmosphere in electrolytic process; then getting refractory metals or alloys which is electrolyzation product. The invention has short flow of production, low energy consumption, little contamination, and is easy to product continuously.

Description

technical field [0001] The invention relates to a method for electrolytically refining refractory active metals and alloys from refractory active metal compounds, which is particularly suitable for the extraction of heavy rare earth metals and their alloys, and belongs to metallurgy of rare earth metal materials. Background technique [0002] Rare earth metals are important raw materials for magnetic materials, and various new magnetic functional alloys (such as permanent magnets, magnetostrictive, magneto-optical recording materials, etc.) composed of heavy rare earth metals and iron-based metals have been more and more widely used. At present, there are two methods for preparing heavy rare earth metals: metallothermic reduction and reduction-distillation. These methods require the use of pure active metal reducing agents and are carried out in an oxygen-free environment. Usually, the oxides need to be chlorinated or fluorinated in advance. The process is complicated, the p...

AI Technical Summary

Problems solved by technology

However, the difference between the decomposition voltage of heavy rare earth oxides or oxychlorides and the decomposition voltage of calcium oxide is only 20-50mV, and the deposition of calcium will inevitably occur at the same time when electrolytically reducing solid heavy rare earth oxides. Solid heavy rare earth compounds are difficult to reduce to the corresponding metals because the applied electrochemical polarization is too small, so it is considered that heavy rare earth metals can only be extracted through metallothermal reduction.

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