Method for preparing metal beryllium by electrolyzing beryllium oxide through fluoride molten salt

Abstract

The invention discloses a method for preparing metal beryllium by electrolyzing beryllium oxide through fluoride molten salt, which comprises the following steps: (1) constructing a BeF2-MFn molten salt system, where MFn is one or more of alkali metal fluoride or alkaline earth metal fluoride except beryllium fluoride; (2) adding beryllium oxide into a BeF2-MFn molten salt system in a molten state; and (3) electrolysis is conducted, and solid-state metal beryllium is separated out on the cathode. According to the method, beryllium smelting intermediate product beryllium oxide is adopted as a raw material and dissolved in fused salt, beryllium ions and oxygen ions are dissociated, due to positive and negative phase attraction, the oxygen ions with negative electricity move to an anode and lose electrons, oxygen or carbon-containing gas is obtained, the beryllium ions with positive electricity move to a cathode, and the electrons are reduced into beryllium atoms to be deposited on the surface of the cathode; according to the method, the technological process is greatly shortened, and the direct recovery rate of beryllium is increased; and beryllium oxide is used as a raw material, carbon dioxide and oxygen are generated on the anode, and the method is more environment-friendly.

Description

technical field [0001] The invention relates to a method for preparing metal beryllium by electrolyzing beryllium oxide with fluoride molten salt, belonging to the field of beryllium metallurgy. Background technique [0002] Beryllium is an indispensable material for national defense, aerospace and nuclear industries, especially high-purity beryllium, which is the only choice for the first wall of nuclear energy "artificial sun", space telescopes and space strategic defense device systems. It is a typical "Strategic and key" engineering materials are directly related to the development of national defense cutting-edge technologies and strategic emerging industries. [0003] At present, most enterprises use beryllium fluoride magnesium thermal reduction method to produce metal beryllium, but there are also a small number of enterprises that use beryllium chloride molten salt electrolysis method to produce metal beryllium. Beryllium fluoride magnesium thermal reduction method...

AI Technical Summary

Problems solved by technology

[0006] Chinese patent CN 109295309 B discloses a method for preparing metal beryllium by reducing beryllium chloride. The method utilizes sodium or potassium to reduce beryllium chloride to prepare metal beryllium. The method requires beryllium chloride as a raw material, but as mentioned above, oxidation Chlorination of beryllium is very difficult

However, calcium metal will dissolve in the molten salt, which increases the electronic conductivity of the molten salt, resulting in a decrease in current efficiency. At the same time, the metal beryllium obtained by reduction tends to contain CaBe 13 Impurities

[0008] Chinese patent CN 111235603 A discloses a method for preparing metal beryllium by electrodeoxidation of molten salt. In this method, beryllium oxide is uniformly mixed with a pore-forming agent and a conductive agent to make a cathode sheet. The obtained metal beryllium will be wrapped on the surface of the electrode, which hinders the diffusion of oxygen ions inside the electrode, making it difficult for the oxygen inside the electrode to diffuse out. At the same time, this method requires the purity of beryllium oxide to be above 99%, which is poor in adaptability to raw materials

[0009] Chinese patent CN 112813288 A discloses a method for preparing high-purity beryllium from industrial beryllium. The industrial beryllium is purified by alkali washing, primary filtration, pickling, and precipitation to obtain beryllium hydroxide, which is then melted with sodium hydroxide and electrolyzed. In the preparation of high-purity beryllium, sodium hydroxide is highly corrosive and severely corrodes equipment, and the anode will generate oxygen, and there is a risk of high-purity beryllium being oxidized again