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CN-122012949-A - Method for preparing metal beryllium by taking beryllium oxide as raw material and improving yield

CN122012949ACN 122012949 ACN122012949 ACN 122012949ACN-122012949-A

Abstract

The invention relates to the technical field of metal beryllium manufacturing, in particular to a method for preparing metal beryllium by taking beryllium oxide as a raw material, which improves the yield. The invention provides a preparation method of high-purity metallic beryllium by taking beryllium oxide as a raw material, calcium hydride, silicon carbide and calcium magnesium alloy are taken as a compound reducing agent, calcium fluoride and aluminum oxide are taken as a compound fluxing agent, the metallic beryllium is prepared by reaction at 1300-1400 ℃, and then a beryllium phase and a slag phase are rapidly separated by a melt centrifugation process, so that the separation efficiency is high, and the direct yield of the metallic beryllium is remarkably improved.

Inventors

  • JIANG SHICHENG
  • XIA WEIGUANG
  • XU XIAOFENG
  • LEI ZHEN

Assignees

  • 上海太洋科技有限公司

Dates

Publication Date
20260512
Application Date
20260318

Claims (8)

  1. 1. A method for preparing metallic beryllium by taking beryllium oxide as a raw material with improved yield comprises the following steps: (S1) uniformly mixing beryllium oxide, calcium hydride, calcium magnesium alloy, silicon carbide, aluminum oxide and calcium fluoride to obtain a mixture, filling the mixture into a crucible, heating the crucible to 1300-1400 ℃ in an inert atmosphere, carrying out heat preservation reaction for 10-15h, and vacuumizing after the reaction to ensure that the vacuum degree of the system is 10-100Pa, and carrying out heat preservation for 1-3h at 1100-1250 ℃; (S2) transferring the crucible into a high-temperature centrifuge, and separating the metal beryllium and the slag phase under the molten state through the density difference of the metal beryllium and the slag phase; (S3) sequentially carrying out ultrasonic cleaning, acid washing, water washing and drying on the metal beryllium to obtain a crude product of the metal beryllium; and (S4) refining the crude product of the metal beryllium in vacuum to obtain the high-purity metal beryllium.
  2. 2. The method according to claim 1, wherein in the step (S1), the mass ratio of beryllium oxide, calcium hydride, calcium magnesium alloy, silicon carbide, aluminum oxide, and calcium fluoride is 1:1.1-1.5:0.3-0.5:0.25-0.6:0.05-0.08:0.02-0.04.
  3. 3. The method according to claim 1, wherein in the step (S1), the mass ratio of beryllium oxide, calcium hydride, calcium magnesium alloy, silicon carbide, aluminum oxide, and calcium fluoride is 1:1.2-1.4:0.3-0.5:0.3-0.4:0.05-0.08:0.02-0.04.
  4. 4. The method according to claim 1, wherein in step (S1), mg in the calcium magnesium alloy is 30-40% and Ca is 60-70%.
  5. 5. The method according to claim 1, wherein in the step (S1), the mixture is uniformly mixed by a three-dimensional mixer, and the inert atmosphere is nitrogen and/or argon.
  6. 6. The method according to claim 1, wherein in step (S1), the particle size of silicon carbide, aluminum oxide, calcium fluoride is independently 300-500nm.
  7. 7. The method according to claim 1, wherein in the step (S2), the process parameters of the high temperature centrifugal furnace are 1300-1400 ℃, the supergravity coefficient is 300-400g, and the separation time is 30-60min.
  8. 8. The method according to claim 1, wherein in the step (S4), the crude product of the metal beryllium is placed in a vacuum induction furnace for vacuum pumping to 0.1-10Pa, the temperature is raised to 800-1000 ℃ firstly, smelting is carried out for 1-2h, then the temperature is raised to 1200-1300 ℃ and the smelting time is 2-3h.

Description

Method for preparing metal beryllium by taking beryllium oxide as raw material and improving yield Technical Field The invention relates to the technical field of metal beryllium manufacturing, in particular to a method for preparing metal beryllium by taking beryllium oxide as a raw material, which improves the yield. Background Beryllium is a rare light metal, has a plurality of excellent performances including low density, low thermal neutron absorption section, high scattering section, high melting point, excellent specific heat and heat conductivity, basically has no change in size when the temperature is changed at 200 ℃, shows excellent dimensional stability, has irreplaceable key effects in the fields of aerospace, nuclear energy, electronics, national defense and the like, and is a strategic resource. The current preparation method of the industrial high-purity beryllium mainly comprises a magnesium thermal reduction method and molten beryllium chloride salt bath electrolytic refining. The magnesiothermic reduction process is to prepare coarse beryllium (purity is 95-97%) with beryllium fluoride as material and magnesium metal as reductant through high temperature reaction, and to prepare high purity metal beryllium through vacuum smelting. The method has the advantages that a shell layer is generated in the reaction process, so that the reaction cannot be continuously carried out, the added magnesium is burnt sharply at high temperature, the whole reduction process is deteriorated, the powdery beryllium obtained by reduction cannot be separated from the reduction product, and excessive beryllium fluoride is required to be added as a flux to enable the reduction process to be normally carried out, so that the direct recovery rate of the beryllium is only about 60%. Thus, various countries have been dedicated to research into new methods for preparing metallic beryllium. Beryllium oxide is the most stable and readily available compound in beryllium metallurgy. It has been a research direction in the art to find a short flow process that can directly and efficiently convert beryllium oxide to metallic beryllium. Beryllium oxide is extremely stable in chemical properties and direct reduction is thermodynamically very difficult. The traditional carbon reduction needs to be carried out at extremely high temperature (more than 1800 ℃), which not only puts severe requirements on equipment, but also leads to serious volatilization loss of beryllium and impurity pollution easily caused by high temperature, and high-purity and high-yield metal products are difficult to obtain. The current technology for preparing beryllium by taking beryllium oxide as a raw material is an electrolytic method. For example, U.S. patent No. 6811678B2 discloses a process for preparing metallic beryllium by electrochemical reduction of solid beryllium oxide in an electrolytic cell comprising an anode, a cathode formed at least in part from beryllium oxide, and a molten electrolyte containing a metal capable of chemically reducing the beryllium oxide, the process comprising operating the electrolytic cell at a level above the cathodic deposition potential of the metal cation by which the beryllium oxide is chemically reduced. This process results in carbon transfer from the graphite anode to the electrolyte and to the cathode product beryllium. And carbon impurities can severely affect the performance of metallic beryllium. CN120006090a discloses a method for roasting beryllium-containing material by using mixed fuel, which mixes beryllium-oxide-containing material with biomass to obtain beryllium-containing mixed material, takes hydrogen and combustion-supporting gas as combustible gas, roasting the beryllium-containing mixed material, and reducing BeO by using C and CO of biomass at high temperature to generate partial metallic beryllium in the roasted product. However, the roasting product obtained by the patent only contains a small amount of beryllium, and the preparation needs to be further carried out by a magnesia-thermal method and a fused salt electrolysis method. And the product will contain a significant amount of carbon impurities. It can be seen that although some technologies for preparing metallic beryllium by direct reduction of beryllium oxide are disclosed in the prior art, the yield and purity, and the economic cost cannot meet the requirement of industrialization. The preparation of metallic beryllium by direct reaction with beryllium oxide using lanthanum, yttrium, thorium-magnesium alloys, zirconium-titanium alloys, and hydrides of lanthanum, yttrium and zirconium as reducing agents has been reported in the literature. However, rare earth metals are expensive, and are not suitable for industrial production because they are used in large quantities as a reduction. The patent before the inventor discloses a method for preparing high-purity metallic beryllium by using calcium hydride and nano silicon carbide as