Method and apparatus for preparing high-purity rare scattered and rare earth metals by means of magnetically controlled zone melting

Abstract

The present invention relates to a method and apparatus for preparing high-purity rare scattered and rare earth metals by means of magnetically controlled zone melting. The apparatus comprises a reaction cavity and a zone melting system. One end of the reaction cavity is provided with a gas input port. The zone melting system comprises a quartz tube arranged in the reaction cavity, a quartz crucible arranged in the quartz tube, a heater used for heating a partial area of a metal material once, and an electromagnetic field generation apparatus used for stirring a melt of the metal material. The heater and the electromagnetic field generation apparatus both can move in the length direction of the reaction cavity. According to the method of the present invention, an external force such as an electromagnetic field is additionally applied to enhance stirring in the zone melting process, thereby reducing the thickness of a diffusion layer, increasing the impurity diffusion coefficient, and achieving deep and efficient removal of impurity elements in the metals. Compared with the prior art, the present invention involves simple operations, and are suitable for horizontal zone melting and vertical zone melting. In addition, the process is low in energy consumption and has no pollution, so that the present invention has good industrial application value.

Description

A method and device for preparing high-purity rare scattered and rare earth metals by magnetron zone melting Technical Field

[0001] The present invention relates to the technical field of metal purification, and in particular to a method and device for preparing high-purity rare and dispersed metals and rare earth metals by magnetron zone melting. Background Art

[0002] With the development of science and technology, especially in the field of cutting-edge science and technology, higher and higher requirements are being placed on the purity of rare and dispersed metals and rare earth metals. The type and amount of impurity elements in rare and dispersed metals have a significant impact on the performance of the materials. Trace or even trace amounts of impurities can also significantly affect the performance of the main metal materials. Ultra-high purification of metals has also become a key link in the preparation of cutting-edge materials. The preparation methods of ultra-high purity metals generally include chemical methods and physical methods: chemical methods usually adopt multi-stage extraction methods, halide methods and electrolytic refining methods, while physical methods include directional solidification, vertical pulling purification, vacuum distillation and zone melting. Among the above methods, the physical method utilizes the difference in physical properties (volatility coefficient, electrical conductivity, magnetic susceptibility and equilibrium distribution coefficient, etc.) between the main metal and the impurity atoms, and no longer undergoes chemical reactions and reduction processes. Therefore, ultra-high purity metals are mostly prepared by physical methods.

[0003] Ultra-high-purity rare and dispersed metals such as gallium, germanium, indium, selenium, tellurium, antimony, bismuth, and rare earth metals have important applications in microelectronics, nuclear detection, communications, energy, transportation, intelligent manufacturing, national defense, and military fields. However, in the preparation of the above-mentioned metals, there are generally many impurity elements with equilibrium distribution coefficients (k0) close to 1. As a result, even if multiple zone melting methods are used, the impurity removal effect is poor, the production efficiency is extremely low, and it is even impossible to produce ultra-high-purity metals above 6N.

[0004] Zone melting (abbreviated as: zone melting) is a deep impurity removal technology for metals. Its essence is to use the difference in solubility of impurities in the solid and molten states of the main metal to achieve directional redistribution of impurities during the alternating solid and liquid states, thereby enriching impurities at the head or tail of the metal rod. Patent CN114293013A discloses a zone melting purification device and method for high-purity metals. It has a high degree of automation, minimizes human interference, and achieves precise and non-fluctuating temperature and driving control. However, this method does not change the conventional zone melting method in terms of improving the efficiency and depth of zone melting. Patent CN101148702A discloses a method and apparatus for purifying metals by zone melting in an electromagnetic composite field. The method combines zone melting with solid-phase electromigration. Under the synergistic action of the magnetic and electric fields, the impurity metal elements migrate toward the cathode, ultimately yielding high-purity metals. However, since the movement of impurity atoms is driven by electron wind in the solid phase, the enormous atomic lattice resistance must be overcome, resulting in an extremely slow migration rate of the impurity atoms. Consequently, the method still suffers from low production efficiency. Furthermore, due to the requirement for a strong current density, the cross-sectional area of ​​the sample is small, limiting the size of the prepared high-purity metal sample. Patent CN111910086A discloses a device for preparing ultrapure indium and a method for preparing it using the device. Through the top self-priming vertical zone melting device and method, it is possible to achieve efficient and stable production of ultrapure indium products of different purity levels of 6N and above. However, the operation of this method is extremely difficult. For many impurity elements in indium with a balanced distribution coefficient K0 close to 1, such as the balanced distribution coefficient of lead in indium is about 1.00-1.07, thallium is about 1.00, magnesium is 1.33-1.70, and tin is 0.73-0.80. The removal efficiency of this zone melting method is very low. In other rare and scattered metals and rare earth metals, there are also many impurity elements with a balanced distribution coefficient K0 close to 1, such as antimony and bismuth are impurities of each other, selenium and tellurium are impurities of each other, and similar element impurities in rare earth metals. The removal effect of multiple zone melting is very low. In vertical zone melting, the upper and lower solid phases rotate in opposite directions, thereby enhancing the transfer coefficient of the liquid phase in the zone, which can improve zone melting efficiency to a certain extent. However, this method is extremely difficult to operate, and the shape of the zone melting section is completely dependent on the surface tension of the melt. The slightest mistake can cause the molten pool to rupture and leak. Therefore, this method still cannot effectively improve the efficiency and separation depth of zone melting. In summary, for many rare and dispersed metals and rare earth metals, there is still a lack of effective means to improve the efficiency of zone melting and prepare ultra-high purity metals.

[0005] Summary of the Invention

[0006] The purpose of the present invention is to overcome the defects of the above-mentioned prior art and provide a method and device for preparing high-purity rare and dispersed rare earth metals by magnetron zone melting.

[0007] The purpose of the present invention can be achieved by the following technical solutions:

[0008] One of the technical solutions of the present invention is to provide a device for preparing high-purity rare and scattered rare earth metals by magnetron zone melting, comprising:

[0009] A reaction chamber, wherein one end of the reaction chamber is provided with a gas input port;

[0010] A zone melting system includes a quartz crucible disposed in the reaction chamber, a metal material disposed in the quartz crucible, a heater for heating a portion of the metal material at a time, and an electromagnetic field generating device for stirring the metal melt, wherein both the heater and the electromagnetic field generating device are movable along the length of the reaction chamber.

[0011] The electromagnetic field generating device generates an alternating magnetic field to generate an induced current in the metal melt. The induced current interacts with the alternating magnetic field to generate Lorentz magnetic force, which stirs the melt.

[0012] Furthermore, the reaction chamber is provided with a quartz tube for placing the quartz crucible, wherein 1 to 5 quartz tubes are provided and arranged along the length of the reaction chamber. The provision of multiple quartz tubes enables simultaneous zone melting purification reaction, thereby improving purification efficiency.

[0013] Furthermore, one to five heaters and five electromagnetic field generators are provided, and the plurality of heaters and electromagnetic field generators are arranged along the length of the reaction chamber. The plurality of heaters and electromagnetic field generators form multiple melting zones, enabling simultaneous zone melting purification reactions, effectively shortening the purification cycle and improving purification efficiency.

[0014] A second technical solution of the present invention is to provide a method for preparing high-purity rare and dispersed rare earth metals by magnetron zone melting. The preparation method is based on the device described in one of the above technical solutions and includes the following steps:

[0015] S1. Place the metal material into a quartz crucible and introduce a protective atmosphere from the gas inlet;

[0016] S2. Move the heater and electromagnetic field generating device outside the quartz tube to one end of the metal material, and turn on the heater and electromagnetic field generating device to perform zone melting and purification on the metal material;

[0017] S3. After the metal material is heated and melted, the heater and the electromagnetic field generating device are moved from one end of the metal material to the other end. At this time, the impurity atoms in the solute boundary layer between the liquid metal material and the solid metal material migrate. This is the first zone melting purification. After repeated zone melting, the impurity atoms are enriched at the end of the metal material.

[0018] S4. Cut off the end of the metal material that contains impurity atoms to obtain high-purity rare and scattered rare earth metals.

[0019] Furthermore, in step S1, the protective atmosphere is selected from hydrogen or argon, and the gas flow rate of the protective atmosphere is 10 to 500 mL / min.

[0020] Furthermore, in step S1, the metal material is selected from any one of rare scattered metals and rare earth metals.

[0021] Furthermore, in step S2, the heating method of zone melting purification is induction heating or resistance heating, the heating temperature of zone melting purification is 200-2000°C, the moving speed of zone melting purification is 1-100 mm / h, and the normalized melting zone width of zone melting, i.e., melting zone width / metal material length, is 0.01-1.

[0022] Furthermore, in step S2, the current in the electromagnetic field generating device is 1 to 1000 A, the frequency in the electromagnetic field generating device is 1 to 1000 Hz, and the electromagnetic field generating device operates in a continuous stirring, intermittent stirring, or alternating stirring mode.

[0023] Furthermore, in step S2, the zone melting purification method is horizontal zone melting or vertical zone melting.

[0024] Furthermore, in step S3, the number of zone melting purification is 1 to 30 times.

[0025] Research shows that the equilibrium distribution coefficient k0 has harsh application conditions and the impurity distribution coefficient in the actual zone melting process is affected by many factors. Therefore, the effective distribution coefficient (k eff ) Modify the equilibrium distribution coefficient k0:

[0026] In the above formula, D is the diffusion coefficient of impurities in the main metal, v is the melting zone movement rate, ξ is the diffusion layer thickness, and k0 is the equilibrium distribution coefficient. For a certain zone melting system, the diffusion coefficient D and the diffusion layer thickness ξ are known. The smaller the melting zone movement rate v, the greater the k eff The closer to the equilibrium distribution coefficient k0, the better the zone melting effect; however, when the melting zone movement velocity v is small, the purification cycle is longer and the efficiency is lower. When the number of zone melting is small, the impurity removal effect of the wide melting zone is good; conversely, the impurity removal effect of the narrow melting zone is better.

[0027] For an uncertain zone melting system, the impurity diffusion coefficient D is mainly affected by temperature. The higher the temperature, the larger the D value. The diffusion layer thickness ξ is mainly affected by the stability of the melting zone. When there is external stirring, the ξ value can be reduced and the D value can be increased, resulting in a better impurity removal effect.

[0028] In addition, maintaining a reducing atmosphere during the zone melting process can effectively improve the removal rate of certain impurities.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] (1) The present invention adds an electromagnetic field generator to a conventional zone melting device, using the force / energy effects of a multi-mode electromagnetic field to control the momentum transfer behavior of impurity atoms at the solid-liquid interface during metal crystallization or zone melting, the thickness of the diffusion boundary layer, the composite phase transition, the field-driven effect, and the effective equilibrium distribution coefficient K0 of the disproportionate impurity components. The present invention utilizes the electromagnetic field force effect to drive the melt flow, thereby reducing the thickness of the diffusion layer at the solidification front and achieving deep and efficient removal of impurity elements in the metal.

[0031] (2) The electromagnetic field induces macro / micro flow in the molten pool, promotes the transport of impurities accumulated in the diffusion layer, and increases the impurity diffusion coefficient D of the impurity atoms, thereby improving the efficiency of zone melting.

[0032] (3) The present invention is simple to operate and is applicable not only to horizontal zone melting but also to vertical zone melting. The electromagnetic field generating device has low energy consumption and is pollution-free during use. Therefore, the method of the present invention has good value for industrial application.

[0033] (4) The present invention has a wide range of applications. It is not only suitable for the zone melting purification of rare and scattered metals and rare earth metals, but also has reference value for the impurity removal processes of all other metals or semi-metals, non-metals, compounds, salts, etc. that are suitable for zone melting, and provides a new idea for the preparation of highly purified materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] FIG1 is a schematic diagram of the structural device of Example 1.

[0035] FIG2 is a schematic diagram of the structural device of Example 2.

[0036] FIG3 is a schematic diagram of the structural device of Comparative Example 1.

[0037] The markings in the figure are as follows: 1 is the reaction chamber, 2 is the quartz crucible, 3 is the quartz tube, 4 is the gas inlet, 5 is the heater, 6 is the electromagnetic field generating device, 7 is the metal material, 8 is the liquid phase at the solidification front of the metal material, 9 is the impurity atom, 10 is the diffusion layer, 11 is the fixing frame, a is the forced flow of the melt, and b is the natural flow of the melt. DETAILED DESCRIPTION

[0038] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0039] In the following examples and comparative examples, unless otherwise specified, raw materials or processing techniques are conventional commercially available raw materials or conventional processing techniques in the art. Furthermore, unless otherwise specified, functional components or structures are conventional components or structures used in the art to achieve the corresponding functions.

[0040] Example 1:

[0041] As shown in Figure 1, the device for preparing high-purity rare and dispersed rare earth metals by magnetic zone melting in this embodiment includes: a horizontally placed reaction chamber 1, a zone melting system arranged in the reaction chamber 1, and a gas inlet 4 arranged at one end of the reaction chamber 1. The zone melting system includes a quartz tube 3 arranged in the reaction chamber 1, a quartz crucible 2 arranged in the quartz tube 3, a heater 5 arranged in the outer ring of the reaction chamber 1 and surrounding the quartz crucible 2, and an electromagnetic field generating device 6 arranged outside the heater 5. Both the heater 5 and the electromagnetic field generating device 6 can move along the length direction of the reaction chamber 1. The quartz crucible 2 is a high-purity quartz crucible, the quartz tube 3 is a high-purity quartz tube, the heater 5 is a heating coil, and the electromagnetic field generating device 6 is an induction coil. The stirring intensity is adjusted by changing the current size and frequency connected to the induction coil.

[0042] Based on this device, a method for preparing high-purity metallic indium by magnetron zone melting includes the following steps:

[0043] S1. Place metallic indium (purity 4N) into a high-purity quartz crucible 2, and introduce a protective atmosphere - high-purity argon gas - from a gas inlet 4 at a flow rate of 100 mL / min.

[0044] S2. Move the heater 5 and electromagnetic field generator 6 outside the high-purity quartz tube 3 to the leading end of the metal indium. Apply direct current to the heater 5 to begin heating and melting the metal indium. Then turn on the electromagnetic field generator 6, set the current of the electromagnetic field generator 6 to 30A, set the frequency of the electromagnetic field generator 6 to 25Hz, and set the stirring mode of the electromagnetic field generator 6 to continuous stirring. Move the heater 5 and electromagnetic field generator 6 from the leading end to the trailing end of the metal indium at a speed of 10mm / h (i.e., the zone melting speed) to perform zone melting purification. The zone melting purification temperature is set to 300°C, and the normalized melting zone width (melting zone width / metal indium ingot length) of the zone melting purification is 0.1. During the movement, ensure that the electromagnetic field generator 6 always acts on the liquid phase 8 at the solidification front of the metal indium. The electromagnetic field generator 6 induces forced flow a of the melt in the liquid phase 8 at the solidification front of the metal indium to reduce the thickness of the diffusion layer 10, thereby promoting the directional migration of impurity atoms 9. After one zone melting purification is completed, the heater 5 and the electromagnetic field generating device 6 are returned to the head end of the metal indium. After the metal indium cools down, the zone melting is repeated 10 times.

[0045] S3. Detect the distribution of impurity atoms 10 at the head, middle, and tail ends of the metallic indium by GD-MS or ICP-MS, and cut off the end containing impurity atoms 9 enriched on the metallic indium to obtain high-purity metallic indium with a purity of 7N.

[0046] This embodiment purifies metallic indium by horizontal zone melting. By selectively adjusting parameters such as the protective atmosphere, zone melting rate, number of zone melting cycles, and zone length, an optimal horizontal zone melting process is explored. During the zone melting process, the distribution of impurity atoms 9 in the main metal is primarily determined by the impurity content in the diffusion layer 10. Therefore, the thickness of the diffusion layer 10 has a significant impact on the distribution of impurity atoms 9 during the zone melting process. A thin diffusion layer 10 facilitates the migration of impurity atoms 9. During the zone melting process, the thickness of the diffusion layer 10 can be reduced by enhancing stirring through external forces such as an electromagnetic field. When the melt only experiences thermal convection, the thickness of the diffusion layer 10 is typically approximately 1.0 mm, which can be reduced to 0.1 mm after stirring, and to 0.01 mm with enhanced stirring. This embodiment utilizes the force / energy effect of a multi-mode electromagnetic field to regulate the momentum transfer behavior of impurity atoms 9 at the solid-liquid interface during the zone melting process of metallic indium, the thickness of the diffusion layer 10, the complex phase transition, the field-driven effect, and the equilibrium distribution coefficient K0 of the disproportionate impurity atoms 9, thereby achieving efficient impurity removal.

[0047] Example 2:

[0048] As shown in Figure 2, the device for preparing high-purity rare and dispersed rare earth metals by magnetic zone melting in this embodiment includes: a vertically placed reaction chamber 1, a zone melting system arranged in the reaction chamber 1, a gas inlet 4 arranged at one end of the reaction chamber 1, and a fixed frame 11 for supporting the reaction chamber. The zone melting system includes a quartz tube 3 arranged in the reaction chamber 1, a quartz crucible 2 arranged in the quartz tube 3, a heater 5 arranged in the outer ring of the reaction chamber 1 and surrounding the quartz crucible 2, and an electromagnetic field generating device 6 arranged outside the heater 5. Both the heater 5 and the electromagnetic field generating device 6 can move along the length direction of the reaction chamber 1. The quartz crucible 2 is a high-purity quartz crucible, the quartz tube 3 is a high-purity quartz tube, the heater 5 is a heating coil, and the electromagnetic field generating device 6 is an induction coil. The stirring intensity is adjusted by changing the current size and frequency connected to the induction coil.

[0049] Based on this device, a method for preparing high-purity metallic indium by magnetron zone melting includes the following steps:

[0050] S1. Place metallic indium (purity 4N) into a high-purity quartz crucible 2, and input a protective atmosphere - high-purity argon gas - from a gas inlet 4 at a flow rate of 100 mL / min.

[0051] S2. Move the heater 5 and electromagnetic field generator 6 outside the high-purity quartz tube 3 to the leading end of the metal indium. Apply direct current to the heater 5 to begin heating and melting the metal indium. Then turn on the electromagnetic field generator 6, set the current of the electromagnetic field generator 6 to 30A, set the frequency of the electromagnetic field generator 6 to 25Hz, and set the stirring mode of the electromagnetic field generator 6 to continuous stirring. Move the heater 5 and electromagnetic field generator 6 from the leading end to the trailing end of the metal indium at a speed (i.e., zone melting speed) of 10mm / h to perform zone melting purification. The temperature of the zone melting purification is set to 300°C, and the normalized melting zone width of the zone melting purification (melting zone width / metal indium ingot length) is 0.1. During the movement, ensure that the electromagnetic field generator 6 always acts on the liquid phase 8 at the solidification front of the metal indium. The electromagnetic field generator 6 induces forced flow a of the melt in the liquid phase 8 at the solidification front of the metal indium to reduce the thickness of the diffusion layer 10, thereby promoting the directional migration of impurity atoms 9. After one zone melting purification is completed, the heater 5 and the electromagnetic field generating device 6 are returned to the head end of the metal indium. After the metal indium cools down, the zone melting is repeated 10 times.

[0052] S3. Detect the distribution of impurity atoms 10 at the head, middle, and tail ends of the metallic indium by GD-MS or ICP-MS, and cut off the end containing impurity atoms 9 enriched on the metallic indium to obtain high-purity metallic indium with a purity of 7N.

[0053] Comparative Example 1:

[0054] Compared with embodiment 1, most of the parts are the same except that the electromagnetic field generating device 6 is omitted.

[0055] As shown in FIG3 , the apparatus for preparing high-purity rare and dispersed metals and rare earth metals by non-magnetron zone melting in this embodiment includes: a horizontally placed reaction chamber 1, a zone melting system disposed in the reaction chamber 1, and a gas inlet 4 disposed at one end of the reaction chamber 1. The zone melting system includes a quartz tube 3 disposed in the reaction chamber 1, a quartz crucible 2 disposed in the quartz tube 3, and a heater 5 disposed on the outer ring of the reaction chamber 1 and surrounding the quartz crucible 2. The heater 5 can move along the length direction of the reaction chamber 1. The quartz crucible 2 is a high-purity quartz crucible, and the quartz tube 3 is a high-purity quartz tube.

[0056] Based on this device, a method for preparing high-purity metallic indium by non-magnetic zone melting includes the following steps:

[0057] S1. Place metallic indium (purity 4N) into a high-purity quartz crucible 2, and input a protective atmosphere - high-purity argon gas - from a gas inlet 4 at a flow rate of 100 mL / min.

[0058] S2. Move the heater 5 outside the high-purity quartz tube 3 to the leading end of the metal indium. Apply direct current to the heater 5 to begin heating and melting the metal indium. Move the heater 5 from the leading end to the trailing end of the metal indium at a speed (i.e., zone melting speed) of 10 mm / h to perform zone melting purification. The zone melting purification temperature is set to 300°C. The normalized zone width of the zone melting purification melt (zone width / metal indium ingot length) is 0.1. The melt naturally flows b in the liquid phase 8 at the solidification front of the metal indium. After one zone melting purification is completed, return the heater 5 to the leading end of the metal indium. After the metal indium cools, repeat the zone melting cycle 10 times.

[0059] S3. Detect the distribution of impurity atoms 10 at the head, middle, and tail ends of the metallic indium by GD-MS or ICP-MS, and cut off the end containing impurity atoms 9 enriched on the metallic indium to obtain metallic indium with a purity of 5N.

[0060] Compared with Example 1, the purity of metallic indium after zone melting purification without magnetron conditions is lower.

[0061] This comparative example is about the purification of metallic indium without magnetron zone melting in the horizontal direction. Since the greater the deviation of the equilibrium distribution coefficient k0 from 1, the better the removal effect of the impurity atom 9 by the zone melting process; the closer the equilibrium distribution coefficient k0 is to 1, the more difficult it is to remove the impurity atom 9, so it is necessary to increase the number of zone melting times to improve the impurity removal rate.

[0062] The above description of the embodiments is intended to facilitate understanding and use of the invention by those skilled in the art. It will be apparent that those skilled in the art can readily make various modifications to these embodiments and apply the general principles described herein to other embodiments without requiring inventive effort. Therefore, the present invention is not limited to the above-described embodiments. Improvements and modifications made by those skilled in the art based on the disclosure of the present invention, without departing from the scope of the present invention, should be within the scope of protection of the present invention.

Claims

1. A device for preparing high-purity rare and scattered rare earth metals by magnetron zone melting, It is characterized in that include: A reaction chamber (1), wherein a gas inlet (4) is provided at one end of the reaction chamber (1); A zone melting system, the zone melting system comprising a quartz crucible (2) arranged in the reaction chamber (1), a metal material (7) arranged in the quartz crucible (2), a heater (5) for heating a partial area of ​​the metal material (7) at one time, and an electromagnetic field generating device (6) for stirring the melt of the metal material (7), wherein the heater (5) and the electromagnetic field generating device (6) are both movable along the length direction of the reaction chamber (1).

2. The device according to claim 1, It is characterized in that A quartz tube (3) for placing the quartz crucible (2) is also provided in the reaction chamber (1), and 1 to 5 quartz tubes (3) are provided, and a plurality of the quartz tubes (3) are arranged along the length direction of the reaction chamber (1).

3. The device according to claim 1, It is characterized in that The heater (5) and the electromagnetic field generating device (6) are each provided with 1 to 5, and the plurality of heaters (5) and the plurality of electromagnetic field generating devices (6) are arranged along the length direction of the reaction chamber (1).

4. A method for preparing high-purity rare and scattered rare earth metals by magnetron zone melting, It is characterized in that Based on the device as described in any one of claims 1 to 3, the preparation method comprises the following steps: S1, placing a metal material (7) into a quartz crucible (2), and introducing a protective atmosphere from a gas inlet (4); S2, moving the heater (5) and the electromagnetic field generating device (6) outside the quartz tube (3) to one end of the metal material (7), and turning on the heater (5) and the electromagnetic field generating device (6) to perform zone melting and purification on the metal material (7); S3. After the metal material (7) is heated and melted, the heater (5) and the electromagnetic field generating device (6) are moved so that the heater (5) and the electromagnetic field generating device (6) are moved from one end of the metal material (7) to the other end. At this time, the impurity atoms (9) in the diffusion layer (10) between the liquid metal material and the solid metal material (7) migrate. This is the first zone melting purification. After repeated zone melting for multiple times, the impurity atoms (9) are enriched at the end of the metal material (7); S4. Cut off one end of the metal material (7) containing impurity atoms (9), thereby obtaining high-purity rare and dispersed rare earth metals.

5. A method for preparing high-purity rare and scattered rare earth metals by magnetron zone melting according to claim 4, It is characterized in that In step S1, the protective atmosphere is selected from hydrogen or argon, and the gas flow rate of the protective atmosphere is 10 to 500 mL / min.

6. A method for preparing high-purity rare and scattered rare earth metals by magnetron zone melting according to claim 4, It is characterized in that In step S1, the metal material (1) is selected from any one of rare scattered metals and rare earth metals.

7. A method for preparing high-purity rare and scattered rare earth metals by magnetron zone melting according to claim 4, It is characterized in that In step S2, the heating method of zone melting purification is induction heating or resistance heating, the heating temperature of zone melting purification is 200-2000°C, the moving speed of zone melting purification is 1-100 mm / h, and the normalized melting zone width of zone melting, i.e., the melting zone width / the length of the metal material (1) is 0.01-1.

8. The method for preparing high-purity rare and scattered rare earth metals by magnetron zone melting according to claim 4, It is characterized in that In step S2, the current in the electromagnetic field generating device (6) is 1 to 1000A, the frequency in the electromagnetic field generating device (6) is 1 to 1000Hz, and the electromagnetic field generating device (6) acts in a continuous stirring, intermittent stirring or alternating stirring manner.

9. A method for preparing high-purity rare and scattered rare earth metals by magnetron zone melting according to claim 4, It is characterized in that In step S2, the zone melting purification method is horizontal zone melting or vertical zone melting.

10. The method for preparing high-purity rare scattered and rare earth metals by magnetron zone melting according to claim 4, It is characterized in that In step S3, the number of zone melting purification is 1 to 30 times.

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