A high-purity tellurium high-efficiency zone melting method and device

Abstract

The present invention relates to the technical field of high-purity material preparation, and discloses a high-purity tellurium high-efficiency zone melting method and device, including a heat exhaust vent, an outer cavity of the device, an inner cavity of the device, a zone melting tube, a zone melting boat, a heating plate, a heating row, an intelligent control system and a servo transmission system. The heat exhaust vent acts to adjust the temperature in the outer cavity. The outer cavity of the device acts to maintain the constant temperature of the inner cavity and reduce the temperature of the outer shell; the inner cavity of the device wraps the heating row, which acts on the cavity wall to keep it warm and insulate, so as to reduce heat loss; the heating row is a plurality of groups of heating rows, each group has an adjustable spacing, and each group has two layers of 8 heating plates in total; the side of the heating plate is equipped with a temperature-controlled thermocouple for controlling the temperature of the heating plate; the servo transmission system is composed of a servo motor and a ball screw, the heating row is connected to the servo transmission system, and the heating plate is driven by the servo motor to move. The device has an intelligent control system, which can realize automatic operation after feeding. At the same time, the production cycle is short, the efficiency is high, the energy consumption is low, and the quality is stable.

Description

Technical Field

[0001] The invention patent relates to the technical field of high-purity material preparation, and in particular to a high-purity tellurium high-efficiency zone melting method and device. Background Art

[0002] 7N (99.99999%) high-purity tellurium is the basic raw material for the preparation of compound semiconductor materials such as mercury cadmium telluride and cadmium zinc telluride. Mercury cadmium telluride and cadmium zinc telluride are very important infrared optoelectronic materials and key materials for high-performance refrigerated infrared detectors. They have mature applications in both military and civilian fields, such as infrared detection, infrared guidance, infrared imaging, satellite remote sensing, etc. Due to the smoke-penetrating and temperature-measuring properties of infrared imaging, infrared thermal imagers can be used in fire rescue and detection equipment for firefighting. In addition, cadmium zinc telluride crystals can convert X-ray and gamma-ray photons into electrons at room temperature, and cadmium zinc telluride detectors have high resolution and low radiation. The application of cadmium zinc telluride crystals as X-ray and gamma-ray detectors in the field of medical examinations has gradually matured. The purity of high-purity tellurium materials is an important factor that directly affects the performance of the above materials.

[0003] The zone melting process is an effective and indispensable process in the purification of high-purity tellurium. At present, the relevant zone melting devices have been greatly improved. For example, the invention patent ZL 201110221111 adopts a vertically suspended zone melting device, which has the advantage of avoiding pollution caused by material contact with the container; the invention patent ZL200710304284 designs the zone melting device into a "C" shape, and adopts a rotary heating coil and a tray to form a zone melting device, which has the advantages of stable operation and small space occupied in production; the invention patent ZL200710047496 combines zone melting with solid phase electromigration, and under the synergistic effect of the magnetic field and the electric field, the impurity metal elements migrate toward the cathode direction, and finally obtain high-purity metal; the invention patent ZL201720457716 adopts multiple high-frequency electric furnace tubes to be flexibly connected to the quartz tube to form multiple melting zones, which improves the zone melting efficiency.

[0004] However, there are still the following problems: 1. When the heating coil used in the existing equipment for zone melting of high-purity materials is wound, the axial width and gap of each turn of the coil are wide, making it difficult to control the width of the melting zone during the zone melting process. At the same time, the existence of the coil gap will lead to unsatisfactory zone melting heating effect. 2. The old-fashioned resistive heating coil is matched with an alumina shell, and the heating coil is loosely structured in the shell. After long-term heating, the heating coil softens and forms a local short circuit and fuses. When it fuses, it often causes damage to the alumina furnace plate, the heating coil has a short life, and the heating furnace plate needs to be replaced frequently. 3. The high-frequency or medium-frequency circuit tube has high energy consumption as a heater, and there is electromagnetic interference, which has certain safety hazards. 4. The heater in the zone melting process needs to travel from the head to the tail of the zone melting boat, and the required travel is long, which leads to a large volume of the zone melting device. 5. There are few melting zones, long zone melting cycles, and low efficiency. 6. After the heater returns to the head each time, it needs to stay for a long time to re-form the melting zone and then start driving, and the zone melting efficiency is low. 7. The traditional zone melting device does not have an insulating inner cavity, and the temperature difference during the zone melting process is large. The tellurium ingot and the quartz zone melting boat expand and contract greatly. The material in the tail impurity enrichment zone is easy to flow back to the purified tellurium ingot area, affecting the quality of the product. At the same time, the quartz zone melting boat is easy to explode and needs to be stopped for cooling before replacement, affecting production efficiency and cost. The lack of an insulating inner cavity leads to large heat loss and high energy consumption. Summary of the invention

[0005] The present invention mainly solves the technical problems existing in the above-mentioned zone melting purification and provides a high-purity tellurium high-efficiency zone melting method and device.

[0006] In order to achieve the above purpose, the present invention adopts the following technical scheme, including a heat exhaust port, an outer cavity of the device, an inner cavity of the device, a zone melting tube, a zone melting boat, a heating plate, a heating row, an intelligent control system and a servo transmission system. The heat exhaust port is located at the top center of the device and is connected to the external exhaust system to exhaust excess heat from the outer cavity of the device and maintain a constant temperature of the outer cavity.

[0007] The outer cavity of the device is located between the inner cavity of the device and the outer shell, and the heat in the outer cavity is discharged from the heat exhaust port to maintain a constant temperature of the inner cavity and reduce the temperature of the outer shell.

[0008] The inner cavity of the device is wrapped with a heating row, and the inner cavity wall is provided with a heat-insulating layer, which is used to maintain a constant temperature of the inner cavity, reduce heat loss of the inner cavity during zone melting operation, improve thermal energy utilization, and reduce energy consumption.

[0009] The heating rows are multiple groups of heating rows, and the spacing between each group can be adjusted as needed. The heating rows are used to fix the heating discs and thermocouples, and are connected to the servo drive system to move the heating discs during the zone melting process; each group of heating rows is provided with two layers of upper and lower heating discs, with 4 discs on each layer. The first group of heating rows is the preheating row, which reduces the time of stopping and melting materials during the zone melting process, and the zone melting efficiency is high.

[0010] Preferably, the servo transmission system consists of a servo motor and a ball screw, and the heating row is mounted on the ball screw to control the moving direction and speed of the heating row.

[0011] Preferably, the heating plate is fixed on a heating row, and a group of heating rows fixes multiple heating plates. The characteristic is that the heating plate is made of high-temperature resistant material and is cast and calcined integrally with the heating furnace wire. The spacing between the furnace wires is uniform and tight, which greatly extends the service life. The heating plate is equipped with a thermocouple, and the temperature of the heating plate and the heating rate are controlled by an intelligent temperature control system.

[0012] Preferably, the thermocouple is installed on the side of the heating plate to detect the temperature of the heating plate in real time and feed the result back to the intelligent temperature control system, thereby controlling the temperature of the heating plate.

[0013] Preferably, the zone melting tube is made of high-purity quartz material, and the device is provided with upper and lower double rows of quartz tubes, with 4 tubes in each row, each tube passes through the heating plate and is aligned with the center of the heating plate, the two ends of the tube body are fixed on the inner cavity, the head cover plate has a protective gas inlet pipe, and the tail cover plate has an exhaust gas exhaust pipe; a zone melting boat is installed in the zone melting tube.

[0014] Preferably, the exhaust pipe is connected to an exhaust processor to cool and wash the exhaust gas, collect tellurium powder in the exhaust gas, and prevent the tellurium powder from entering the terminal exhaust gas treatment system, thereby achieving the purpose of reducing losses and protecting the environment.

[0015] Preferably, the head of the quartz zone melting boat is aligned with the second group of heating rows, the spacing between each group of heating rows is fixed and consistent, and the stroke of each group of heating rows is just the distance between the two groups of heating rows. During the zone melting process, when the eighth group of heating rows moves to the tail of the zone melting boat (the tail of the ingot), the first group of heating rows has formed a melting zone at the head of the zone melting boat (the head of the ingot); then the servo transmission system drives the heating rows to automatically and quickly return to the fixed stroke, and the second group of heaters returns to the melting zone at the head of the ingot, so as to carry out zone melting production in a reciprocating relay. In this method, the zone melting stroke is fixed to one heating row spacing, the stroke is short, and the melting zone at the head of the zone melting boat has been formed before returning, so there is no need to stop the machine for melting, and the efficiency is high. At the same time, during the zone melting process, the tellurium ingot always maintains multiple melting zones, and the inner cavity temperature fluctuates in a small range until the parking procedure is entered, which effectively prevents the backflow of the melting zone caused by thermal expansion and contraction, and improves the stability of product quality.

[0016] Preferably, the intelligent control system consists of a touch screen, a PLC, a control program, etc. All control interfaces and parameter settings are displayed and set through the touch screen, and the control and automated production of the equipment are realized through the control program and PLC. After setting the zone melting process parameters, automatic production and data recording can be carried out.

[0017] A method for preparing high-purity tellurium comprises the following steps:

[0018] S1: ReferenceFigure 1 As shown, the device outer cavity 1, the device inner cavity 14, the heating row 13, the heating plate 12, the servo motor 10 and the ball screw 9 are installed in sequence.

[0019] S2: Pass the zone melt tube 6 horizontally through the heating row 13 and align it with the center of the heating row. Leave a gap between the heating plate 12 and the tube body to prevent the tube from being scratched during driving. Both ends of the tube body are fixed on the inner cavity of the device; cover the left end of the tube body with a sealing cover plate 5 and connect the protective gas inlet 15; put 5N tellurium material into the zone melt boat 7, and put the zone melt boat horizontally into the zone melt tube. The left side of the zone melt boat head is aligned with the left end of the second heating row to ensure that 7 melting zones are formed after 2-7 groups of heat discharge materials; cover the right end of the zone melt tube with a sealing cover plate and connect the exhaust gas evolver 8.

[0020] S3: The protective gas inlet 15 of the device is connected to the external gas supply system. The external gas supply is switched to the argon gas supply valve, and argon is introduced. The argon flow rate is controlled at 0.5-2L / min. The zone melting tube is ventilated for 30-60min to replace the air in the zone melting tube body; when the external gas supply is switched to the hydrogen gas supply valve, hydrogen is introduced, and the hydrogen flow rate is controlled at 0.5-2L / min. Hydrogen is passed into the zone melting tube for 150-180min. Its function is to make the heated tellurium material not easily oxidized. The oxidized material at high temperature is reduced by hydrogen. At the same time, trace impurities such as Se and S react with H2 at 230-500℃ to generate H2Se and H2S, which are carried away by the tail gas in gaseous state.

[0021] S4: Turn on the power of the heating plate, control the temperature of the heating plate to 650℃±100℃, and start heating to melt the material for the first time; after the tellurium material is melted, adjust the temperature of the heating plate in time, control the width of the melting zone to 50-70mm, and prevent the melting zone from sticking; start the servo motor, control the overall movement speed of the heating row to 40±10mm / h, and the heating row automatically moves to the right at a uniform speed as a whole to start the zone melting operation; during the zone melting process, the temperature of the inner cavity 14 of the device is constant at 300±50℃; there is a heat exhaust vent 2 above the outer cavity 1 of the device, and the heat exhaust vent is connected to the external exhaust system to discharge the heat in the outer cavity in time, reduce the temperature of the outer cavity and the outer shell, and ensure that the temperature of the inner cavity is constant.

[0022] S5: Figure 3 As shown, when the eighth group of heating rows begins to pass through the tail of the ingot on the right side of the zone melting, the first group of heating rows moves to the head of the ingot, and a new melting zone is formed at the head of the ingot. Then the servo transmission system drives the heating rows to automatically and quickly return to the fixed stroke to the initial position, and the second group of heaters returns to the melting zone at the head of the ingot to start a new round of zone melting. In this reciprocating relay, zone melting production is carried out. After 15-20 times of driving, 5N tellurium material can be purified to 6N.

[0023] S6: When the number of returns reaches the set number, the machine will stop automatically. After the driving is completed, the external hydrogen supply is switched to the argon supply valve, and the gas is ventilated for 30-60 minutes to replace the hydrogen in the zone melting tube, and the zone melting boat ingot is taken out, and 18%-25% of the head and tail are removed. The middle section is the 6N tellurium with stable quality.

[0024] S7: Use the above 6N tellurium as raw material to reload the car, and re-zone melt according to the above process. Control the moving speed of the heating row to 30±10mm / h, the melting zone width to 40-60mm, drive 12-18 times, remove 15%-20% of the head and tail, and obtain a 7N high-purity tellurium product with stable quality.

[0025] Beneficial Effects

[0026] The present invention provides a high-purity tellurium high-efficiency zone melting method and device, which has the following beneficial effects:

[0027] (1) In this method and device for high-purity tellurium high-efficiency zone melting, the heating plate is made of high-temperature resistant material and is integrally cast and calcined with the heating wire. The spacing between the wires is uniform and tight, and the thermal field is stable, which greatly extends the service life of the heating plate and the heating wire. At the same time, a step-down transformer is used in the control of the heating wire, which can reach the melting temperature while reducing the operating energy consumption.

[0028] (2) A high-purity tellurium high-efficiency zone melting method and device, wherein the entire zone melting process in the device is carried out under a high-purity hydrogen atmosphere, and during the zone melting process, the tellurium ingot and the molten tellurium liquid are not oxidized and do not cause product contamination, thereby improving product quality.

[0029] (3) This high-purity tellurium high-efficiency zone melting method and device is equipped with multiple groups of heating rows. Multiple melting zones can be formed on the same zone melting ingot at the same time. The first row of heaters assists in forming the first melting zone of the ingot. A reciprocating relay zone melting method is adopted. After returning to the machine, there is no need to stop the machine to melt the material to form the melting zone. Compared with the traditional zone melting device, the same heating row has a small moving stroke, the device size is small, there is no backflow in the melting zone, the zone melting efficiency is high, and the product quality is stable.

[0030] (4) This high-purity tellurium high-efficiency zone melting method and device has an internal heat-insulating inner cavity. The temperature of the inner cavity can be kept relatively constant during the zone melting process. The temperature difference of the material during the zone melting process is small, the stress accumulation caused by thermal expansion and contraction deformation is small, and the zone melting boat is not easy to break.

[0031] (5) This high-purity tellurium high-efficiency zone melting method and device is equipped with an intelligent control system. After the parameters are set, it can realize one-key automatic start, automatic operation, automatic recording, automatic parking, automatic alarm, etc. No human intervention is required during the zone melting process. It has a high degree of automation, high safety, and stable product quality.

[0032] (6) A high-purity tellurium high-efficiency zone melting method and device. Using this method and device to produce high-purity tellurium materials by zone melting, the method and device have low energy consumption per unit product, high production efficiency, and high product purity, and can be used to stably prepare 6N-7N5 high-purity tellurium.

[0033] (7) The high-purity tellurium high-efficiency zone melting method and device can also be applied to the production and purification of other high-purity materials, such as 6N-7N high-purity zinc, tin, lead, antimony, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the implementation of the present invention or the technical solution in the prior art, the following briefly introduces the drawings required for the implementation or the description of the prior art. Obviously, the drawings in the following description are only exemplary, and for ordinary technicians in this field, other implementation drawings can be derived from the provided drawings without creative work.

[0035] The structures, proportions, sizes, etc. illustrated in this specification are only used to match the contents disclosed in the specification so as to facilitate understanding and reading by persons familiar with the technology. They are not used to limit the conditions under which the present invention can be implemented, and therefore have no substantial technical significance. Any structural modification, change in proportion or adjustment of size shall still fall within the scope of the technical contents disclosed in the present invention without affecting the effects and purposes that the present invention can produce.

[0036] Figure 1 Device structure diagram

[0037] Figure 2 Heater schematic diagram

[0038] Figure 3 Heating row schematic diagram

[0039] Legend:

[0040] 1. Device outer cavity; 2. Heat exhaust vent; 3. Exhaust exhaust vent; 4. Insulation layer; 5. Sealing cover plate; 6. Zone melting tube; 7. Zone melting boat; 8. Exhaust purifier; 9. Ball screw; 10. Servo motor; 11. Thermocouple; 12. Heating plate (12a, heating furnace wire, 12b, heating plate shell, 12c, heating furnace wire joint, 12d, thermocouple mounting hole); 13. Heating row; 14. Device inner cavity; 15. Protective gas inlet. DETAILED DESCRIPTION

[0041] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0042] Example

[0043] The quality of the 6N high-purity tellurium product prepared according to the steps of the high-purity tellurium preparation method is shown in Table 1. Table 1 is a comparison of the 6N high-purity tellurium produced by the method of the present invention by glow discharge mass spectrometer (GDMS) analysis and test results with the standard "High Purity Tellurium" YS / T 817-2012, and all indicators are better than the standard requirements of 6N high-purity tellurium.

[0044] Table 1 6N high purity tellurium glow discharge mass spectrometer (GDMS) analysis results

[0045]

[0046]

[0047] In the embodiment, the above 6N tellurium is used as raw material for reloading, and zone melting is performed again according to the above preparation steps. The moving speed of the heating row is controlled to be 20 mm / h, the melting zone width is 40±5 mm, and the moving is performed 15 times. After removing 18% of the head and tail, a 7N high-purity tellurium product with stable quality can be obtained.

[0048] Table 2 is a comparison of the analysis and test results of 7N high-purity tellurium produced by the method of the present invention using a glow discharge mass spectrometer (GDMS) and the standard "Ultra-High Purity Tellurium" YS / T 1192-2017, and the indicators are better than the standard requirements of 7N ultra-high purity tellurium.

[0049] Table 2 7N high purity tellurium glow discharge mass spectrometer (GDMS) analysis results

[0050]

[0051] It can be seen from the above table that the impurity content and purity of the 6N and 7N high-purity tellurium materials prepared by the method of the present invention are better than the YS / T 817-2012 high-purity tellurium (6N) and YS / T1192-2017 ultra-high-purity tellurium (7N) standards.

[0052] Working principle of the present invention:

[0053] During the zone melting process, the heat of the outer cavity 1 of the device is discharged from the hot exhaust port 2 to reduce the temperature of the outer cavity and the shell; the protective gas inlet 15 is connected to the external gas supply system to provide argon or hydrogen for the zone melting process; the exhaust gas purifier 8 is connected to the sealing cover plate 5, and the exhaust gas generated during the zone melting process is treated by the purifier for dust reduction, and then connected to the external exhaust system through the exhaust gas exhaust port 3 to discharge the purified exhaust gas; a heating plate 12 is installed on the heating row 13, and the spacing between each group of heating rows is constant and fixed on the ball screw 9. The ball screw is connected to the servo motor 10 to form a servo transmission system to control the moving speed and direction of the heating row during the zone melting process; the heating plate 12 is fixed on the heating row; the zone melting tube 6 passes horizontally through the heating plate, and a gap is reserved between the tube wall and the heating plate to prevent the tube from being scratched during driving. Both ends of the zone melting tube are fixed on the inner cavity; the zone melting boat 7 is loaded with tellurium raw materials and placed horizontally in the zone melting tube, and the left end of the boat is flush with the left side of the second group of heating rows. During melting, one zone melting boat can form 7 melting zones; the first group of heaters is for auxiliary melting function, and zone melting purification is carried out in a reciprocating relay manner; the sealing cover plate 5 seals both ends of the zone melting tube, and the left cover plate is connected to the protective gas inlet 15, through which protective gas can be introduced into the zone melting tube, and the right cover plate is connected to the exhaust gas purifier 8; the device is equipped with an intelligent control system. After setting the zone melting parameters, it can automatically drive and record with one button, and no manual intervention is required during the zone melting process.

[0054] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the invention, the present invention may have various changes and improvements (including but not limited to the increase or decrease of the number of heating rows), and these changes and improvements fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A high-purity tellurium high-efficiency zone melting device, characterized in that: It comprises a heat exhaust port (2), an outer chamber (1) of the device, an inner chamber (14) of the device, a zone melting tube (6), a zone melting boat (7), a heating plate (12), a heating row (13), an intelligent control system and a servo drive system; The heat exhaust port (2) is located at the top center of the device and is connected to an external exhaust system to exhaust excess heat in the outer cavity (1) of the device and maintain a constant temperature of the outer cavity; The device outer cavity (1) is located between the device inner cavity (14) and the device housing, and the heat of the device outer cavity (1) is discharged from the heat exhaust port to maintain a constant temperature of the inner cavity and reduce the temperature of the housing; The inner cavity (14) of the device wraps around the heating row (13), and the inner cavity wall has a heat-insulating layer (4) for maintaining a constant inner cavity temperature, reducing heat loss in the inner cavity during zone melting operation, improving thermal energy utilization, and reducing energy consumption; The heating row (13) is a plurality of groups of heating rows (13) used to fix the heating disks (12) and the thermocouples (11), and each group of heating rows (13) is provided with two layers of heating disks, one above the other, with four heating disks on each layer; The servo transmission system is composed of a servo motor (10) and a ball screw (9), and the heating row (13) is installed on the ball screw (9) to control the moving direction and moving speed of the heating row; The intelligent control system is composed of a touch screen, a PLC, and a control program. All control interfaces and parameter settings are displayed and set through the touch screen, and the control program and PLC are used to control the equipment and realize automatic production. After the zone melting process parameters are set, automatic production and data recording can be carried out. The heating rows (13) include eight groups, each group has a fixed spacing, and each group of heating rows (13) has a travel distance that is just the distance between two groups of heating rows; in the initial state, the left end of the zone melting boat (7) is flush with the left side of the second group of heating rows (13), and when the eighth group of heating rows moves to the tail of the zone melting boat, the first group of heating rows has formed a melting zone at the head of the zone melting boat; The heating disc (12) is annular in shape and is fixed on a heating row (13). A group of heating rows fixes a plurality of heating discs (12). The heating disc (12) is made of a high-temperature resistant material and is integrally cast and calcined with a heating furnace wire (12a). The furnace wires are spaced evenly and tightly together, thereby greatly extending the service life. The heating disc (12) is equipped with a thermocouple (11). The temperature and heating rate of the heating disc (12) are controlled by an intelligent temperature control system. The thermocouple (11) is installed on the side of the heating disc (12) and is used to detect the temperature of the heating disc in real time and feed the result back to the intelligent temperature control system, thereby controlling the temperature of the heating disc. The zone melting tube (6) passes through the heating plate (12) horizontally, and the zone melting boat (7) loaded with tellurium raw materials is placed horizontally in the zone melting tube (6) to isolate the external environment and ensure that the zone melting process is carried out in a stable and clean environment; The two ends of the zone melting pipe (6) are sealed by a sealing cover plate (5), a protective gas inlet (15) is connected to the left cover plate to form a closed environment for the zone melting pipe, and a protective gas is introduced into the zone melting pipe (6), and a tail gas purifier (8) is connected to the right cover plate, and the zone melting tail gas is discharged through the tail gas exhaust port after being processed by the purifier (8); The inner cavity (14) of the device wraps around the heating row (13); the cavity wall has a heat-insulating layer (4), which ensures that the temperature of the inner cavity is fixed within a required range during the zone melting process, maintains a constant temperature of the inner cavity, reduces heat loss in the inner cavity during the zone melting process, improves thermal energy utilization, reduces energy consumption, and reduces the temperature variation range of the inner cavity, thereby reducing the influence of thermal expansion and contraction during the zone melting process on the quartz zone melting boat (7), thereby achieving the purpose of protecting the quartz zone melting boat (7).

2. A high-purity tellurium high-efficiency zone melting device according to claim 1, characterized in that: When the eighth group of heating rows moves to the tail of the zone melting boat, the first group of heating rows has formed a melting zone at the head of the zone melting boat; then the servo drive system drives the heating rows (13) to automatically and quickly return to the fixed stroke, and the second group of heating rows returns to the melting zone at the head of the ingot, thereby carrying out zone melting production in a reciprocating relay; during the zone melting process, there is no need to stop the material for melting, which can improve the zone melting efficiency. At the same time, during the zone melting process, the tellurium ingot always maintains multiple melting zones, and the inner cavity temperature fluctuates in a smaller range until the parking program is entered, effectively preventing the melting zone backflow caused by thermal expansion and contraction, thereby improving the quality of the product.

3. A high-purity tellurium high-efficiency zone melting device according to claim 2, characterized in that: A heating plate (12) is installed on the heating row (13), and each group of heating rows (13) is fixed on a ball screw (9). The ball screw (9) is connected to a servo motor (10) to form a servo transmission system, which is used to control the moving speed and moving direction of the heating row (13) during the zone melting process.

4. A high-purity tellurium high-efficiency zone melting device according to claim 3, characterized in that: The zone melting boat (7) is made of high-purity quartz and is used to hold tellurium materials during the zone melting process. The head of the zone melting boat (7) is flush with the second group of heating rows. The heating plate (12) is used to form a plurality of melting zones and solidification zones for the tellurium materials in the zone melting boat (7). The servo transmission system drives the heating rows (13) to move to realize the movement of the tellurium melting zones, thereby purifying the tellurium ingot.

5. A high-purity tellurium high-efficiency zone melting device according to claim 4, characterized in that: The protective gas inlet (15) is connected to an external gas supply system to provide high-purity argon or high-purity hydrogen for the zone melting process. The high-purity argon is used to replace the air in the quartz tube before starting and to replace the hydrogen in the quartz tube after stopping, thereby ensuring production safety. The high-purity hydrogen is used as a protective gas to ensure that the heated tellurium material is not easily oxidized. At the same time, trace Se and S impurities react with H2 at 230-500°C to generate H2Se and H2S and are taken away by the tail gas in a gaseous state, thereby achieving the purpose of removing Se and S impurities in the tellurium material.

6. A high-purity tellurium high-efficiency zone melting device according to claim 5, characterized in that: The exhaust gas purifier (8) is connected to the sealing cover plate (5), and the exhaust gas generated in the zone melting process is subjected to dust reduction treatment by the purifier (8), and tellurium dust in the exhaust gas is collected. After being washed with water, the exhaust gas is discharged into the exhaust gas exhaust port; the exhaust gas exhaust port (3) is connected to an external exhaust system for discharging the purified exhaust gas, and also serves the purpose of reducing the loss of tellurium material.

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