Method for preparing metal beryllium by taking beryllium oxide as raw material and improving yield

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 and improving the yield. According to the preparation method of the high-purity metal beryllium with the beryllium oxide as the raw material, calcium hydride, silicon carbide and calcium-magnesium alloy serve as compound reducing agents, calcium fluoride and aluminum oxide serve as compound fluxing agents, the metal beryllium is prepared through a reaction at the temperature of 1300-1400 DEG C, then the beryllium phase and the slag phase are rapidly separated through the melting centrifugal technology, the separation efficiency is high, and the purity is high. And the direct yield of the metal beryllium is obviously improved.

Description

Technical Field

[0001] This invention relates to the field of beryllium metal manufacturing technology, and more specifically to a method for preparing beryllium metal from beryllium oxide as a raw material with improved yield. Background Technology

[0002] Beryllium is a rare light metal with many excellent properties, including low density, low thermal neutron absorption cross section, high scattering cross section, high melting point, and excellent specific heat and thermal conductivity. When the temperature changes by up to 200℃, the dimensions of beryllium products remain essentially unchanged, exhibiting excellent dimensional stability. It plays an irreplaceable and crucial role in aerospace, nuclear energy, electronics, and defense fields, making it a strategic resource. Currently, the main industrial methods for preparing high-purity beryllium are the magnesothermic reduction method and molten beryllium chloride salt bath electrolytic refining.

[0003] The magnesothermic reduction method uses beryllium fluoride as a raw material and metallic magnesium (or other highly reducing metals such as sodium, potassium, or barium) as a reducing agent to produce crude beryllium (typically with a purity of 95-97%) under high-temperature conditions. High-purity metallic beryllium is then produced through processes such as vacuum melting. During the reaction, a shell layer forms, preventing the reaction from proceeding continuously. Furthermore, the added magnesium burns rapidly at high temperatures, worsening the entire reduction process. The resulting powdered beryllium cannot be separated from the reduction products, requiring the addition of excess beryllium fluoride as a flux to allow the reduction process to continue normally. Therefore, the direct recovery rate of beryllium is only about 60%. Consequently, various countries have dedicated themselves to researching new methods for preparing metallic beryllium.

[0004] Beryllium oxide is the most stable and readily available compound in beryllium metallurgy. Finding a direct and efficient short-process method to convert beryllium oxide into metallic beryllium has been a long-standing research focus in this field. Beryllium oxide is chemically extremely stable, making direct reduction thermodynamically very difficult. Traditional carbon reduction requires extremely high temperatures (above 1800°C), which not only places stringent demands on equipment but also leads to significant volatilization losses and impurity contamination of beryllium, making it difficult to obtain high-purity, high-yield metallic products. Currently, the electrolytic method is the primary technique for preparing beryllium from beryllium oxide. For example, US Patent 6811678B2 discloses a method for preparing metallic beryllium by electrochemical reduction of solid beryllium oxide. This patent involves reducing solid beryllium oxide in an electrolytic cell, which includes an anode, a cathode at least partially composed of beryllium oxide, and a molten electrolyte containing a metal capable of chemically reducing beryllium oxide. The core process of this method is to operate the electrolytic cell at a condition higher than the deposition potential of the metal cation cathode, thereby chemically reducing beryllium oxide. This method causes carbon to transfer from the graphite anode to the electrolyte and then to the cathode product, beryllium. Carbon impurities severely affect the performance of metallic beryllium. CN120006090A discloses a method for roasting beryllium-containing materials using mixed fuels. The beryllium-containing mixture is obtained by mixing beryllium oxide-containing materials with biomass, and hydrogen and combustion-supporting gases are used as combustible gases to roast the beryllium-containing mixture. The C and CO of the biomass reduce BeO at high temperature, resulting in the production of some metallic beryllium in the roasting product. However, the calcined product obtained by this patent contains only a small amount of beryllium, which needs to be further processed using the magnesothermic method and molten salt electrolysis. Moreover, the product contains a large amount of carbon impurities. It is evident that although some existing technologies disclose techniques for the direct reduction of beryllium oxide to prepare metallic beryllium, the yield, purity, and economic cost still do not meet the requirements for industrialization.

[0005] Literature reports the use of lanthanum, yttrium, thorium, thorium-magnesium alloys, zirconium-titanium alloys, and lanthanum, yttrium, and zirconium hydrides as reducing agents to directly react with beryllium oxide to prepare metallic beryllium. However, rare earth metals are expensive, require large quantities for reduction, and are not suitable for industrial production.

[0006] The inventor's previous patent disclosed a method for preparing high-purity metallic beryllium using calcium hydride and nano-silicon carbide as a composite reducing agent at 1300-1500℃, with a yield of up to 80%. Although this is an improvement over the magnesothermic reduction method, further improvements in yield are still desired. Summary of the Invention

[0007] Given that existing methods for directly reducing beryllium oxide to prepare high-purity metallic beryllium are not suitable for industrial application and suffer from shortcomings in yield, purity, and economic cost, this invention proposes a method for preparing metallic beryllium using beryllium oxide as a raw material. This invention improves the reduction system formulation by adding calcium-magnesium alloy and calcium fluoride, lowering the melting point of the slag phase and improving its fluidity. This facilitates subsequent separation of metallic beryllium from the slag phase via melt centrifugation, thereby increasing the yield and significantly shortening the separation time, making it more suitable for industrial production. Specifically, this invention provides the following technical solutions to achieve the above objectives:

[0008] A method for preparing metallic beryllium from beryllium oxide with improved yield includes the following steps:

[0009] (S1) Beryllium oxide, calcium hydride, calcium-magnesium alloy, silicon carbide, aluminum oxide, and calcium fluoride are mixed evenly to obtain a mixture. The mixture is placed in a crucible and heated to 1300-1400℃ under an inert atmosphere, and the reaction is maintained at this temperature for 10-15 hours. After the reaction, the system is evacuated to a vacuum of 10-100 Pa and held at 1100-1250℃ for 1-3 hours.

[0010] (S2) Transfer the crucible to a high-temperature centrifuge and separate the beryllium metal and the slag phase in the molten state by the density difference between the beryllium metal and the slag phase;

[0011] (S3) Beryllium metal is sequentially subjected to ultrasonic cleaning, acid washing, water washing, and drying to obtain crude beryllium metal;

[0012] (S4) Crude beryllium metal is refined under vacuum to obtain high-purity beryllium metal.

[0013] The reducing agents of this invention are calcium hydride and silicon carbide, with the addition of a certain amount of calcium-magnesium alloy. This alloy is molten at the reaction temperature, which enhances interfacial mass transfer and prevents poor contact between the solid reducing agent and beryllium oxide. The reduction product MgO, at low content, can improve the slag fluidity, thus synergistically improving the yield of metallic beryllium. Another improvement of this invention is the addition of a small amount of calcium fluoride, which reacts with alumina, silicon dioxide, magnesium oxide, and other components at high temperatures to form a low-melting-point eutectic phase. This phase has good fluidity and easily separates from metallic beryllium, further optimizing the slag structure and promoting the aggregation and sedimentation of metallic beryllium droplets. Calcium fluoride may also optimize the surface tension of the slag system, reducing the wettability between the product metallic beryllium and the slag phase, promoting beryllium aggregation, reducing the slag's coating of metallic beryllium, and improving the direct yield of metallic beryllium. The silicon carbide in the raw materials of this invention will generate CH4 and be discharged from the system at high temperature. Even if there is a small amount of elemental carbon, the wettability of carbon with the silicate slag phase is much better than that with metallic beryllium. Therefore, elemental carbon will not enter the beryllium phase. Subsequently, through melt centrifugation, elemental carbon and slag phase are separated to the lower layer, and there is basically no carbon residue in the upper layer of metallic beryllium.

[0014] Further, in step (S1), the mass ratio of beryllium oxide, calcium hydride, calcium-magnesium alloy, silicon carbide, alumina, 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; even further, Mg accounts for 30-40% and Ca accounts for 60-70% in the calcium-magnesium alloy. The reduction product MgO can adjust the phase composition of the slag system, forming a multi-component eutectic system with CaO, Al2O3, and SiO2. Within the optimized ratio range, it can improve the fluidity and interfacial properties of the slag system, and promote the aggregation and sedimentation of metallic beryllium droplets. However, the MgO content cannot be too high and needs to be strictly controlled, as excessive MgO content will lead to an increase in the melting point of the slag phase.

[0015] Furthermore, in step (S1), the purity of all materials is ≥99.9%.

[0016] Further, in step (S1), the uniform mixing is achieved using a three-dimensional mixer, a high-speed stirrer, or a ball mill. Preferably, a three-dimensional mixer is used. In this invention, uniform mixing is achieved under an inert atmosphere using a three-dimensional mixer. The inert atmosphere is nitrogen and / or argon, the spindle speed of the three-dimensional mixer is 20-30 rpm, and the mixing time is 30-60 min.

[0017] Furthermore, in step (S1), the particle sizes of silicon carbide, alumina, and calcium fluoride are independently 300-500 nm. The inventors discovered that the particle sizes of silicon carbide, alumina, and calcium fluoride affect the reaction results. The aforementioned particle size of 300-500 nm allows the reaction to proceed smoothly with high beryllium yield and high purity. The nanoscale particle size of these substances ensures a large specific surface area, allowing them to fully participate in the reaction. However, the particle size cannot be too small, otherwise agglomeration is likely.

[0018] Furthermore, in step (S2), the process parameters of the high-temperature centrifuge are 1300-1400℃, the hypergravity coefficient is 300-400g, and the separation time is 30-60min. This invention, through reasonable optimization of the formula, further lowers the melting point of the slag phase, placing it within a temperature range higher than the melting point of metallic beryllium but lower than the 1500℃ required for beryllium volatilization. This utilizes the density difference between the beryllium phase and the slag phase in the molten state to completely solve the slag phase encapsulation problem through melt centrifugation. This significantly improves the direct yield of metallic beryllium, with a preferred embodiment achieving over 90%. Moreover, the melt centrifugation method offers high phase separation efficiency and short processing time. Although energy consumption and cost are higher, the substantial increase in production efficiency makes it more suitable for industrialization.

[0019] Further, in step (S3), ball milling reduces the beryllium particle size to 1-2 mm at a milling speed of 200-300 rpm and a ball-to-material ratio of 10-20:1; ultrasonic cleaning involves placing the beryllium particles into a horizontal cleaning machine, adding water, and cleaning under ultrasonic conditions; preferably, the ultrasonic frequency is 40-100 kHz. Ultrasonic cleaning cleans the coarse beryllium particles through mechanical collision and vibration, removing slag from the surface and removing deposits from the surface and crevices of the coarse beryllium particles; acid washing involves soaking the water-washed beryllium particles in 5-10 wt% nitric acid to remove impurities such as metal oxides from the surface; water washing involves washing with deionized water until neutral (pH value approximately 7). Drying is performed under vacuum or an inert atmosphere to reduce the moisture content to below 0.1%.

[0020] Further, in step (S4), vacuum refining involves placing crude beryllium metal into a vacuum induction furnace, evacuating it to 0.1-10 Pa, first heating it to 800-1000℃ and melting it for 1-2 hours, then heating it to 1200-1300℃ and melting it for 2-3 hours.

[0021] The present invention has achieved the following beneficial effects:

[0022] This invention uses beryllium oxide as a raw material and, through a compound reducing agent, achieves a one-step direct reduction of beryllium oxide to prepare metallic beryllium. By rationally optimizing the formulation of the compound reducing agent and flux, and by adding a certain amount of calcium-magnesium alloy and calcium fluoride, the slag structure is optimized, promoting the aggregation and sedimentation of metallic beryllium droplets; a highly fluid slag is formed, which facilitates the separation of metallic beryllium and the slag through melting and centrifugation. The combined effect of these factors significantly improves the direct yield of metallic beryllium, greatly enhancing production efficiency. The metallic beryllium obtained by this invention has a purity of over 99%, and the direct yield (based on beryllium content) is over 90%. Detailed Implementation

[0023] The technical solution of the present invention will be further explained and described below with reference to specific embodiments.

[0024] The beryllium oxide is from Shanghai Taiyang Technology Co., Ltd., with a purity of ≥99.9%.

[0025] Calcium hydride, silicon carbide, calcium fluoride, and alumina are all commercially available and have a purity of ≥99.9%. The calcium-magnesium alloy contains 61.74% Ca, 38.15% Mg, and ≤50ppm C impurities.

[0026] Example 1

[0027] (S1) Beryllium oxide, calcium hydride, calcium-magnesium alloy, nano-silicon carbide (particle size approximately 300 nm), nano-alumina (particle size approximately 500 nm), and nano-calcium fluoride (particle size approximately 300 nm) were added in a mass ratio of 1:1.3:0.4:0.34:0.06:0.03 and mixed uniformly using a three-dimensional mixer (spindle speed 20 rpm, mixing time 60 min) to obtain a mixture. The mixture was then placed in a crucible and placed in a high-temperature furnace. Under an argon atmosphere, the temperature was increased to 1350℃ at a heating rate of 5℃ / min and held for 15 h. After the reaction, the system was evacuated to a vacuum of 50 Pa and held at 1250℃ for 2 h.

[0028] (S2) Transfer the crucible to a high-temperature centrifuge and separate the metallic beryllium and slag phases by melting and centrifuging at 1300℃, a hypergravity coefficient of 300g, and a separation time of 30min.

[0029] (S3) Beryllium metal was ball-milled at a speed of 200 rpm and a ball-to-material ratio of 10:1 to make the beryllium metal particles about 2 mm in diameter. The beryllium metal particles were placed in a horizontal cleaning machine, tap water was added, and the cleaning was carried out at an ultrasonic frequency of 60 kHz for 10 h. After that, it was acid-washed with 10% dilute nitric acid and finally washed with deionized water until neutral. Under a nitrogen atmosphere, it was dried in an oven at 80 ℃ until the moisture content was ≤0.1% to obtain crude beryllium metal.

[0030] (S4) The crude beryllium metal was placed in a vacuum melting furnace, the furnace cover was closed, the vacuum valve was opened, and the vacuum was evacuated to 0.1 Pa. The temperature was first raised to 850°C and melted for 1 hour, and then the temperature was raised to 1250°C and melted for 2 hours. After the beryllium was completely melted, it was directly cast in the furnace. After the casting was complete, the furnace body was cooled to room temperature with water to obtain high-purity beryllium metal with a purity of 99.3% and a carbon impurity content of 32 ppm. The direct yield of beryllium metal was 91.5%.

[0031] Example 2

[0032] (S1) Beryllium oxide, calcium hydride, calcium-magnesium alloy, nano-silicon carbide (particle size approximately 500 nm), nano-alumina (particle size approximately 300 nm), and nano-calcium fluoride (particle size approximately 500 nm) were added in a mass ratio of 1:1.2:0.5:0.4:0.08:0.02 and mixed uniformly using a three-dimensional mixer (spindle speed 20 rpm, mixing time 60 min) to obtain a mixture. The mixture was then placed in a crucible and placed in a high-temperature furnace. Under an argon atmosphere, the temperature was increased to 1400℃ at a heating rate of 5℃ / min and held for 12 h. After the reaction, the system was evacuated to a vacuum of 50 Pa and held at 1150℃ for 2 h.

[0033] (S2) Transfer the crucible to a high-temperature centrifuge and separate the metallic beryllium and slag phases by melting and centrifuging at 1350℃, a hypergravity coefficient of 400g, and a separation time of 30min.

[0034] (S3) Beryllium metal was ball-milled at a speed of 200 rpm and a ball-to-material ratio of 10:1 to make the beryllium metal particles about 2 mm in diameter. The beryllium metal particles were placed in a horizontal cleaning machine, tap water was added, and the cleaning was carried out at an ultrasonic frequency of 60 kHz for 10 h. After that, it was acid-washed with 10% dilute nitric acid and finally washed with deionized water until neutral. Under a nitrogen atmosphere, it was dried in an oven at 80 ℃ until the moisture content was ≤0.1% to obtain crude beryllium metal.

[0035] (S4) The crude beryllium metal was placed in a vacuum melting furnace, the furnace cover was closed, the vacuum valve was opened, and the vacuum was evacuated to 0.1 Pa. The temperature was first raised to 800°C and melted for 2 hours, and then the temperature was raised to 1300°C and melted for 2 hours. After the beryllium was completely melted, it was directly cast in the furnace. After the casting was complete, the furnace body was cooled to room temperature with water to obtain high-purity beryllium metal with a purity of 99.2% and a carbon impurity content of 47 ppm. The direct yield of beryllium metal was 90.7%.

[0036] Example 3

[0037] (S1) Beryllium oxide, calcium hydride, calcium-magnesium alloy, nano-silicon carbide (particle size approximately 300 nm), nano-alumina (particle size approximately 500 nm), and nano-calcium fluoride (particle size approximately 300 nm) were added in a mass ratio of 1:1.4:0.3:0.3:0.05:0.04 and mixed uniformly using a three-dimensional mixer (spindle speed 20 rpm, mixing time 60 min) to obtain a mixture. The mixture was then placed in a crucible and placed in a high-temperature furnace. Under an argon atmosphere, the temperature was increased to 1360℃ at a heating rate of 5℃ / min and held for 15 h. After the reaction, the system was evacuated to a vacuum of 50 Pa and held at 1100℃ for 2 h.

[0038] (S2) Transfer the crucible to a high-temperature centrifuge and separate the metallic beryllium and slag phases by melting and centrifuging at 1350℃, a hypergravity coefficient of 300g, and a separation time of 30min.

[0039] (S3) Beryllium metal was ball-milled at a speed of 200 rpm and a ball-to-material ratio of 10:1 to make the beryllium metal particles about 2 mm in diameter. The beryllium metal particles were placed in a horizontal cleaning machine, tap water was added, and the cleaning was carried out at an ultrasonic frequency of 60 kHz for 10 h. After that, it was acid-washed with 10% dilute nitric acid and finally washed with deionized water until neutral. Under a nitrogen atmosphere, it was dried in an oven at 80 ℃ until the moisture content was ≤0.1% to obtain crude beryllium metal.

[0040] (S4) The crude beryllium metal was placed in a vacuum melting furnace, the furnace cover was closed, the vacuum valve was opened, and the vacuum was evacuated to 0.1 Pa. The temperature was first raised to 1000℃ and melted for 1 hour, and then the temperature was raised to 1300℃ and melted for 2 hours. After the beryllium was completely melted, it was directly cast in the furnace. After the casting was complete, the furnace body was cooled to room temperature with water to obtain high-purity beryllium metal with a purity of 99.3% and a carbon impurity content of 36 ppm. The direct yield of beryllium metal was 91.0%.

[0041] Example 4

[0042] (S1) Beryllium oxide, calcium hydride, calcium-magnesium alloy, nano-silicon carbide (particle size approximately 300 nm), nano-alumina (particle size approximately 500 nm), and nano-calcium fluoride (particle size approximately 300 nm) were added in a mass ratio of 1:1.3:0.6:0.3:0.06:0.03 and mixed uniformly using a three-dimensional mixer (spindle speed 20 rpm, mixing time 60 min) to obtain a mixture. The mixture was then placed in a crucible and placed in a high-temperature furnace. Under an argon atmosphere, the temperature was increased to 1360℃ at a heating rate of 5℃ / min and held for 15 h. After the reaction, the system was evacuated to a vacuum of 50 Pa and held at 1250℃ for 2 h.

[0043] (S2) Transfer the crucible to a high-temperature centrifuge and separate the metallic beryllium and slag phases by melting and centrifuging at 1300℃, a hypergravity coefficient of 300g, and a separation time of 30min.

[0044] (S3) Beryllium metal was ball-milled at a speed of 200 rpm and a ball-to-material ratio of 10:1 to make the beryllium metal particles about 2 mm in diameter. The beryllium metal particles were placed in a horizontal cleaning machine, tap water was added, and the cleaning was carried out at an ultrasonic frequency of 60 kHz for 10 h. After that, it was acid-washed with 10% dilute nitric acid and finally washed with deionized water until neutral. Under a nitrogen atmosphere, it was dried in an oven at 80 ℃ until the moisture content was ≤0.1% to obtain crude beryllium metal.

[0045] (S4) The crude beryllium metal was placed in a vacuum melting furnace, the furnace cover was closed, the vacuum valve was opened, and the vacuum was evacuated to 0.1 Pa. The temperature was first raised to 900°C and melted for 1 hour, and then the temperature was raised to 1250°C and melted for 2 hours. After the beryllium was completely melted, it was directly cast in the furnace. After the casting was complete, the furnace body was cooled to room temperature with water to obtain high-purity beryllium metal with a purity of 99.3% and a carbon impurity content of 44 ppm. The direct yield of beryllium metal was 88.7%.

[0046] Example 5

[0047] (S1) Beryllium oxide, calcium hydride, calcium-magnesium alloy, nano-silicon carbide (particle size approximately 300 nm), nano-alumina (particle size approximately 500 nm), and nano-calcium fluoride (particle size approximately 300 nm) were added in a mass ratio of 1:1.3:0.25:0.3:0.06:0.03 and mixed uniformly using a three-dimensional mixer (spindle speed 20 rpm, mixing time 60 min) to obtain a mixture. The mixture was then placed in a crucible and placed in a high-temperature furnace. Under an argon atmosphere, the temperature was increased to 1360℃ at a heating rate of 5℃ / min and held for 15 h. After the reaction, the system was evacuated to a vacuum of 50 Pa and held at 1250℃ for 2 h.

[0048] (S2) Transfer the crucible to a high-temperature centrifuge and separate the metallic beryllium and slag phases by melting and centrifuging at 1300℃, a hypergravity coefficient of 300g, and a separation time of 30min.

[0049] (S3) Beryllium metal was ball-milled at a speed of 200 rpm and a ball-to-material ratio of 10:1 to make the beryllium metal particles about 2 mm in diameter. The beryllium metal particles were placed in a horizontal cleaning machine, tap water was added, and the cleaning was carried out at an ultrasonic frequency of 60 kHz for 10 h. After that, it was acid-washed with 10% dilute nitric acid and finally washed with deionized water until neutral. Under a nitrogen atmosphere, it was dried in an oven at 80 ℃ until the moisture content was ≤0.1% to obtain crude beryllium metal.

[0050] (S4) The crude beryllium metal was placed in a vacuum melting furnace, the furnace cover was closed, the vacuum valve was opened, and the vacuum was evacuated to 0.1 Pa. The temperature was first raised to 900°C and melted for 1 hour, and then the temperature was raised to 1250°C and melted for 2 hours. After the beryllium was completely melted, it was directly cast in the furnace. After the casting was complete, the furnace body was cooled to room temperature with water to obtain high-purity beryllium metal with a purity of 99.1% and a carbon impurity content of 39 ppm. The direct yield of beryllium metal was 89.2%.

[0051] Comparative Example 1

[0052] (S1) High-purity beryllium oxide, calcium hydride, nano-silicon carbide (particle size approximately 300 nm), and nano-alumina (particle size approximately 500 nm) were mixed uniformly in an argon atmosphere using a three-dimensional mixer (spindle speed 20 rpm, mixing time 60 min) to obtain a mixture. The mixture was placed in a high-temperature furnace and heated to 1400℃ at a heating rate of 5℃ / min under an argon atmosphere and held for 12 h.

[0053] (S2) After the reaction, the system was vacuumed to a vacuum of 70 Pa, kept at 1400℃ for 2 hours, and cooled to room temperature at 20℃ / min. The blocky product in the furnace was broken into about 10 mm, boiled in water at 100℃ for 2 hours in an enamel container, and the metallic beryllium and slag were separated by gravity separation.

[0054] (S3) Ball milling reduces the beryllium particle size to 1-2 mm. The beryllium particles are then placed in a horizontal cleaning machine with tap water added. The machine is cleaned for 10 hours at a 60 kHz ultrasonic frequency to thoroughly remove the adhering substances on the surface and in the depressions of the coarse beryllium. After that, it is acid-washed with 10% dilute nitric acid and finally washed with deionized water until neutral. The product is then dried in an oven at 80°C under a nitrogen atmosphere until the moisture content is ≤0.1%, thus obtaining crude beryllium.

[0055] (S4) The crude beryllium metal was placed in a vacuum melting furnace, the furnace cover was closed, the vacuum valve was opened, the vacuum was drawn to 0.1 Pa, the temperature was raised to 1350℃, and vacuum refining was carried out. After the beryllium was completely melted, it was directly cast in the furnace. After casting was completed, the furnace body was cooled to room temperature with water to obtain high-purity beryllium metal with a purity of 99.3% and a yield of 81.7% based on Be.

Claims

1. A method for preparing metallic beryllium from beryllium oxide as a raw material with improved yield, comprising the following steps: (S1) Beryllium oxide, calcium hydride, calcium-magnesium alloy, silicon carbide, aluminum oxide, and calcium fluoride are mixed evenly to obtain a mixture. The mixture is placed in a crucible and heated to 1300-1400℃ under an inert atmosphere, and the reaction is maintained at this temperature for 10-15 hours. After the reaction, the system is evacuated to a vacuum of 10-100 Pa and held at 1100-1250℃ for 1-3 hours. (S2) Transfer the crucible to a high-temperature centrifuge and separate the beryllium metal and the slag phase in the molten state by the density difference between the beryllium metal and the slag phase; (S3) Beryllium metal is sequentially subjected to ultrasonic cleaning, acid washing, water washing, and drying to obtain crude beryllium metal; (S4) Crude beryllium metal is refined under vacuum to obtain high-purity beryllium metal.

2. The method according to claim 1, characterized in that, In 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. The method according to claim 1, characterized in that, In 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. The method according to claim 1, characterized in that, In step (S1), Mg accounts for 30-40% and Ca accounts for 60-70% in the calcium-magnesium alloy.

5. The method according to claim 1, characterized in that, In step (S1), the mixing is carried out using a three-dimensional mixer; the inert atmosphere is nitrogen and / or argon.

6. The method according to claim 1, characterized in that, In step (S1), the particle size of silicon carbide, alumina, and calcium fluoride is independently 300-500 nm.

7. The method according to claim 1, characterized in that, In step (S2), the process parameters of the high-temperature centrifuge are 1300-1400℃, the hypergravity coefficient is 300-400g, and the separation time is 30-60min.

8. The method according to claim 1, characterized in that, In step (S4), vacuum refining involves placing crude beryllium metal into a vacuum induction furnace, evacuating it to 0.1-10 Pa, first heating it to 800-1000℃ and melting it for 1-2 hours, then heating it to 1200-1300℃ and melting it for 2-3 hours.