Preparation method of metal beryllium ball or beryllium alloy ball

Abstract

The invention discloses a preparation method of a metal beryllium ball or a beryllium alloy ball, and belongs to the technical field of beryllium metallurgy. The preparation method comprises the following steps: placing beryllium or beryllium alloy in a crucible in an induction coil in an intermediate frequency furnace, closing a furnace door, vacuumizing a smelting area and a settling tower, and smelting to obtain a beryllium metal solution or a beryllium alloy solution; the tundish and the drainage pipe are heated, and inert gas is filled into the smelting area and the settling tower till the pressure in the smelting area and the pressure in the settling tower are at least one standard atmospheric pressure; the method comprises the following steps: pouring a beryllium metal solution or a beryllium alloy solution into a tundish, introducing the beryllium metal solution or the beryllium alloy solution into a sedimentation tower filled with inert gas through a drainage pipe, and sequentially performing rotary crushing by a rotary roller, throwing out from the rotary roller and falling down for cooling to form a metal beryllium ball or a beryllium alloy ball. According to the method, the metal beryllium balls or beryllium alloy balls with high ball compactness, low product impurity content and high purity can be prepared, the technological process is short, the production cost is low, operability is achieved, and the method is suitable for industrial production.

Description

Technical Field

[0001] The invention belongs to the technical field of beryllium metallurgy, and in particular relates to a method for preparing a metal beryllium pellet or a beryllium alloy pellet. Background Art

[0002] Beryllium (Be) is considered a "nuclear age metal." Its low atomic weight, low neutron absorption cross section (0.009 bar), high neutron scattering cross section (6.1 bar), and neutron multiplication capacity are unique to other metals. Beryllium also possesses excellent X-ray penetration. A polished beryllium surface reflects 55% of ultraviolet light and 98% of infrared light. In certain applications, beryllium is the only suitable or preferred material, playing an irreplaceable role in the national economy.

[0003] At present, metal beryllium pellets or beryllium alloy pellets are generally selected internationally as neutron multiplication materials for solid tritium breeder blankets. The performance requirements for metal beryllium pellets or beryllium alloy pellets are high sphericity, good fluidity and density, and the particle size is required to be around 1 mm.

[0004] Currently, the main technologies for preparing beryllium metal pellets or beryllium alloy pellets include rotating electrode plasma centrifugal atomization (REP) and molten gas atomization. While REP produces beryllium metal pellets or beryllium alloy pellets with high sphericity and uniform particle size, this method requires the pre-preparation of suitable electrode rods, is lengthy and complex, and requires high equipment requirements. Drainage is difficult, operability is poor, and operational complexity is high, leading to high production costs and a high impurity content. Summary of the Invention

[0005] In view of the above problems, the present invention proposes a method for preparing metal beryllium balls or beryllium alloy balls. The preparation method can produce metal beryllium balls or beryllium alloy balls with high ball density, low product impurity content and high purity, and the process flow is short, the production cost is low, the process is operational, and it is suitable for industrial production.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A method for preparing a metal beryllium pellet or a beryllium alloy pellet, the method comprising the following steps:

[0008] Step S1, placing beryllium or a beryllium alloy in a crucible inside an induction coil in a medium frequency furnace, closing the furnace door, evacuating the smelting area and the settling tower, and then smelting to obtain a beryllium metal solution or a beryllium alloy solution;

[0009] Step S2, heating the tundish and the draft tube to 900-1100° C., and filling the vacuum smelting zone and the settling tower with inert gas until the pressure in the smelting zone and the settling tower is at least 1 standard atmosphere;

[0010] Step S3: After pouring the beryllium metal solution or the beryllium alloy solution into the tundish, the beryllium metal solution or the beryllium alloy solution is introduced into a settling tower filled with inert gas through a drainage pipe, and then the beryllium metal solution or the beryllium alloy solution is successively subjected to rotary roller crushing, thrown out from the rotary roller, and dropped to cool, thereby forming metal beryllium pellets or beryllium alloy pellets.

[0011] Furthermore, in step S1, the vacuum degree in the smelting zone and the settling tower after evacuation is less than 67 Pa.

[0012] Furthermore, in step S1, the vacuum degree in the smelting zone and the settling tower after evacuation is 55-60 Pa.

[0013] Furthermore, in the step S1, the smelting temperature is 1400-1550° C., and the smelting time is 60-110 minutes.

[0014] Furthermore, in step S2, the inert gas is one of argon and helium.

[0015] Furthermore, in step S2, the temperature of the tundish and the draft tube are both 960-1040°C.

[0016] Furthermore, in step S3, the temperature of the beryllium metal solution or the beryllium alloy solution when poured into the tundish is 80-100° C. higher than the melting point of beryllium or the beryllium alloy.

[0017] Furthermore, in step S3, the rotation speed of the rotating roller is 3000-10000 rpm;

[0018] The distance between the rotating roller and the drainage tube is 5 to 10 mm;

[0019] The diameter of the drainage tube is 3 to 6 mm.

[0020] Furthermore, in the step S3, the material of the rotating roller is one of tantalum, niobium, tungsten and titanium.

[0021] Furthermore, in step S3, the average particle size of the metal beryllium pellets or beryllium alloy pellets is 0.2 to 2 mm.

[0022] In summary, the solution proposed in the present invention has the following technical effects:

[0023] The present invention places beryllium or a beryllium alloy in a crucible inside an induction coil in a medium frequency furnace and smelts it in a vacuum, thereby reducing the probability of beryllium or a beryllium alloy being contaminated, preventing oxidation of the beryllium metal solution or the beryllium alloy solution, and improving the performance of the beryllium metal solution or the beryllium alloy solution. The present invention introduces a protective gas into a settling tower to prevent product oxidation and improve cooling efficiency. The present invention forms spheres with uniform particles, high density, and high sphericity through roller granulation. The process of the present invention has huge production capacity, safe production, simple operation, low production cost, and strong product controllability. The metal beryllium pellets or the beryllium alloy pellets of the present invention have an average particle size of 0.2 to 2 mm, a wide particle size adjustment range, and strong process adaptability. DETAILED DESCRIPTION

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention are clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0025] This embodiment discloses a method for preparing a metal beryllium pellet or a beryllium alloy pellet, which comprises the following steps:

[0026] Step S1: placing beryllium or beryllium alloy in a crucible inside an induction coil in a medium frequency furnace, closing the furnace door, evacuating the smelting area and the settling tower, and then smelting to obtain a beryllium metal solution or a beryllium alloy solution.

[0027] In this embodiment, the smelting zone and settling tower are evacuated to ensure that the smelting process is carried out in a vacuum, thereby reducing the chance of raw material contamination, preventing product oxidation, and improving product performance. In this embodiment, the vacuum degree in the smelting zone and settling tower after evacuation is less than 67 Pa, preferably 55-60 Pa.

[0028] In order to ensure that beryllium or beryllium alloy is fully dissolved and to minimize volatile impurities in beryllium or beryllium alloy, thereby ensuring product quality, the smelting temperature in this embodiment is 1400-1550° C. and the smelting time is 60-110 minutes.

[0029] Step S2: heating the tundish and the draft tube to 900-1100° C., and filling the vacuum smelting zone and the settling tower with inert gas until the pressure in the smelting zone and the settling tower is at least 1 standard atmosphere.

[0030] In this embodiment, the tundish and the draft tube are heated to 900-1100° C., preferably 960-1040° C., in order to ensure the atmosphere in the tundish and the draft tube and maintain the fluidity of the beryllium metal melt or the beryllium alloy melt.

[0031] The inert gas in this embodiment is one of argon and helium.

[0032] Step S3: After pouring the beryllium metal solution or the beryllium alloy solution into the tundish, the beryllium metal solution or the beryllium alloy solution is introduced into a settling tower filled with inert gas through a drainage pipe, and then the beryllium metal solution or the beryllium alloy solution is successively subjected to rotary roller crushing, thrown out from the rotary roller, and dropped to cool, thereby forming metal beryllium pellets or beryllium alloy pellets.

[0033] In this embodiment, the temperature of the beryllium metal solution or beryllium alloy solution when poured into the tundish is controlled to be 80-100° C. higher than the melting point of beryllium or beryllium alloy, which can maximize the flow of the metal melt and beryllium alloy melt into the drainage tube and the roller, thereby improving production efficiency and ensuring product quality.

[0034] In this embodiment, the rotation speed of the roller is controlled to be 3000-10000 rpm, thereby ensuring that the average particle size of the metal beryllium pellets or beryllium alloy pellets is between 0.2 and 2 μm.

[0035] To control the average particle size distribution and sphericity of the product and improve product yield, this embodiment controls the spacing between the roller and the drainage tube, as well as the diameter of the drainage tube. The spacing between the roller and the drainage tube is generally 5 to 10 mm, and the diameter of the drainage tube is generally 3 to 6 mm. The roller in this embodiment is made of one of tantalum, niobium, tungsten, and titanium.

[0036] The technical solution of the above embodiment is described below with specific examples:

[0037] Example 1:

[0038] Step S1: Place a metal beryllium block in a crucible inside an induction coil in a medium frequency furnace, close the furnace door, evacuate the smelting area and the settling tower to 55 Pa, power the induction coil, and smelt at a temperature of 1400°C for 60 minutes to obtain a beryllium metal solution.

[0039] Step S2: Simultaneously start the tundish and draft tube heating systems, heat the tundish and the 6 mm diameter draft tube to 900°C, adjust the temperature to the casting temperature after the beryllium melts, 80°C higher than the melting point of beryllium, and fill argon into the vacuum melting zone and settling tower until the pressure in the melting zone and settling tower reaches 1 standard atmosphere.

[0040] Step S3: After pouring the beryllium metal solution into the tundish, the beryllium metal solution is introduced into a settling tower filled with argon through a drainage tube. The tantalum roller motor is then turned on. The beryllium metal solution is then subjected to a series of processes, including rotational crushing by the tantalum roller, ejection from the tantalum roller, and cooling by falling, to obtain beryllium metal pellets. The tantalum roller rotates at 3500 rpm, and the distance between the tantalum roller and the drainage tube is 5 mm.

[0041] The average particle size of the metal beryllium pellets in this embodiment is 2.0 mm, and the purity is 98.3%.

[0042] Example 2:

[0043] Step S1: Place the beryllium block and the titanium block in the crucible inside the induction coil in the medium frequency furnace, close the furnace door, evacuate the melting area and the settling tower to 60 Pa, power the induction coil, and smelt at a temperature of 1550°C for 110 minutes to obtain a beryllium-titanium alloy solution.

[0044] Step S2: Simultaneously start the tundish and draft tube heating systems, heat the tundish and the 3 mm diameter draft tube to 1100°C, and adjust the casting temperature to 100°C higher than the melting point of the beryllium titanium alloy after the beryllium titanium alloy is melted. Fill helium (argon and helium) into the vacuum melting zone and settling tower until the pressure in the melting zone and settling tower reaches 2 standard atmospheres.

[0045] Step S3: After pouring the beryllium-titanium alloy solution into the tundish, the solution is introduced into a helium-filled settling tower through a drainage tube. The niobium roller motor is then turned on. The solution undergoes a series of processes, including rotational crushing by the niobium roller, ejection from the roller, and cooling by falling, to produce beryllium-titanium alloy pellets. The niobium roller rotates at a speed of 10,000 rpm, and the distance between the niobium roller and the drainage tube is 10 mm.

[0046] The average particle size of the beryllium-titanium alloy balls in this embodiment is 0.2 mm, and the purity is 98.2%.

[0047] Example 3:

[0048] Step S1: Place the beryllium block and the vanadium block in the crucible inside the induction coil in the medium frequency furnace, close the furnace door, evacuate the melting area and the settling tower to 65 Pa, power the induction coil, and smelt at a temperature of 1475°C for 80 minutes to obtain a beryllium-vanadium alloy solution.

[0049] Step S2: Simultaneously start the tundish and draft tube heating systems, heat the tundish and the 5 mm diameter draft tube to 1040° C., adjust the temperature to the casting temperature after the beryllium vanadium alloy melts, which is 90° C. higher than the melting point of the beryllium vanadium alloy, and fill helium into the vacuum melting zone and settling tower until the pressure in the melting zone and settling tower reaches 3 standard atmospheres.

[0050] Step S3: After pouring the beryllium-vanadium alloy solution into the tundish, the solution is introduced into a helium-filled settling tower through a draft tube. The tungsten roller motor is then turned on. The solution undergoes a series of processes, including rotational crushing by the tungsten roller, ejection from the roller, and cooling by falling, to produce beryllium-vanadium alloy pellets. The tungsten roller rotates at 3000 rpm, and the distance between the tungsten roller and the draft tube is 7 mm.

[0051] The beryllium-vanadium alloy pellets in this embodiment have an average particle size of 1.1 mm and a purity of 98.1%.

[0052] The above embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art could make various modifications and improvements without departing from the spirit of the present application, all of which fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. A method for preparing a metal beryllium pellet or a beryllium alloy pellet, characterized in that: The preparation method comprises the following steps: Step S1, placing beryllium or a beryllium alloy in a crucible inside an induction coil in a medium frequency furnace, closing the furnace door, evacuating the smelting area and the settling tower, and then smelting to obtain a beryllium metal solution or a beryllium alloy solution; Step S2, heating the tundish and the draft tube to 900-1100° C., and filling the vacuum smelting zone and the settling tower with inert gas until the pressure in the smelting zone and the settling tower is at least 1 standard atmosphere; Step S3: After pouring the beryllium metal solution or the beryllium alloy solution into the tundish, the beryllium metal solution or the beryllium alloy solution is introduced into a settling tower filled with inert gas through a drainage pipe, and then the beryllium metal solution or the beryllium alloy solution is successively subjected to rotary roller crushing, thrown out from the rotary roller, and dropped to cool, thereby forming metal beryllium pellets or beryllium alloy pellets.

2. The preparation method according to claim 1, characterized in that In the step S1, the vacuum degree in the smelting zone and the settling tower after evacuation is less than 67 Pa.

3. The preparation method according to claim 2, characterized in that In the step S1, the vacuum degree in the smelting zone and the settling tower after evacuation is 55-60 Pa.

4. The preparation method according to claim 3, characterized in that In the step S1, the smelting temperature is 1400-1550° C. and the smelting time is 60-110 minutes.

5. The preparation method according to any one of claims 1 to 4, characterized in that In step S2, the inert gas is one of argon and helium.

6. The preparation method according to claim 5, characterized in that In step S2, the temperature of the tundish and the draft tube are both 960-1040°C.

7. The preparation method according to claim 6, characterized in that In step S3, the temperature of the beryllium metal solution or the beryllium alloy solution when poured into the tundish is 80-100° C. higher than the melting point of beryllium or the beryllium alloy.

8. The preparation method according to claim 7, characterized in that In step S3, the rotation speed of the roller is 3000-10000 rpm; The distance between the rotating roller and the drainage tube is 5 to 10 mm; The diameter of the drainage tube is 3 to 6 mm.

9. The preparation method according to claim 8, characterized in that In the step S3, the material of the rotating roller is one of tantalum, niobium, tungsten and titanium.

10. The preparation method according to claim 9, characterized in that In step S3, the average particle size of the metal beryllium pellets or beryllium alloy pellets is 0.2 to 2 mm.