Method for preparing rare earth alloy by molten salt electrolysis

Abstract

Provided in the present invention are a rare earth metal and a rare earth metal alloy and a method for the preparation of these by molten salt electrolysis. In the method for the preparation of the rare earth metal alloy by molten salt electrolysis, the electrolyte is an alkali metal or the chloride-fused salt of an alkaline earth metal, the positive electrode is an inert electrode or graphite, the negative electrode is composed of a rare-earth metal oxide and the oxides of other alloy components and / or metal powders, and electrolysis is induced by the passage of a direct current. During the electrolytic process, the temperature of electrolysis is higher than the melting point of the rare earth metal alloy produced and lower than the melting point of the negative electrode; the surface layer of the positive electrode is in the first stage electrolyzed to a liquid metal film which accumulates to a certain volume before falling to the crucible at the bottom. The current density of the negative electrode is sufficient to separate out from said negative electrode the components of the rare earth metal alloy. The electrolysis voltage is lower than the decomposition potential of the electrolyte and higher than the decomposition potential of the oxides corresponding to each component of the rare earth metal alloy. A crucible is used to collect the rare earth metal and the alloy obtained through the present method. The present method is technically simple and environmentally-friendly, while featuring low energy consumption, high current efficiency, and low costs.

Description

technical field [0001] The invention relates to a method for preparing rare earth metal alloys by molten salt electrolysis, in particular to a method for directly preparing rare earth metal alloys by molten salt electrolysis, which belongs to the field of rare earth metal alloy preparation. Background technique [0002] Rare earth metal alloys play a pivotal role in the field of new materials, and are rare earth permanent magnet materials, rare earth hydrogen storage materials, rare earth nuclear materials, giant magnetostrictive materials, magnetic refrigeration materials, etc. Alloys are important basic raw materials for new functional materials as main components or additives. Rare earth metal alloys are not only widely used in metallurgy, petrochemical and other traditional industries, but also indispensable in the fields of materials such as magnetism, optical fiber communication, hydrogen storage energy, superconductivity, etc., directly affecting optical instruments, ...

AI Technical Summary

Problems solved by technology

The disadvantage of this fluoride salt system oxide co-deposition method is that the rare earth fluoride is used as the main body of the electrolyte system, the oxide is used as the raw material, and the alloy is obtained by dissolving the oxide in the rare earth fluoride first, and then precipitated at the cathode. Due to the high solubility of rare earth metals in their corresponding fluoride electrolyte systems, the dissolution loss is large, and the current efficiency is only 41%.

Although the process is controlled so that the cathode product is precipitated in liquid form, the electrolyte system commonly used at present uses rare earth fluoride as the main component of the electrolyte, so the dissolution loss is large and the yield is low. At the same time, for samarium, europium, etc. The secondary reaction is violent, and the efficiency and rare earth content in the product are lower than expected