A method for manufacturing a quartz crucible and a quartz crucible

Abstract

This invention provides a method for preparing a quartz crucible and the quartz crucible itself. The method employs a vacuum arc melting process. At the first time point in the arc melting process, a fluxing step is performed while maintaining the arc melting. This fluxing step releases heat through the reaction of the flux, increasing the melting temperature. The beneficial effects of this invention are that the flux releases a large amount of heat in the melting zone. This heat, combined with the heat generated by the flux reaction on top of the heat generated by the arc melting, increases the temperature of the melting zone, raises the upper limit of the temperature inside the vacuum arc melting furnace, reduces the viscosity of the inner surface of the molten quartz sand, and improves the density of the inner surface of the quartz crucible. This reduces the number of microbubbles inside the transparent layer and inhibits the expansion of microbubbles that could damage the inner surface, thus improving the quality of the quartz crucible.

Description

Technical Field

[0001] This invention belongs to the technical field of silicon single crystal production equipment, and in particular relates to a method for preparing a quartz crucible and the quartz crucible itself. Background Technology

[0002] As a core component in the Czochralski method for preparing single-crystal silicon, the content of microbubbles on the inner wall of the quartz crucible directly affects the purity and yield of the silicon single crystal. Microbubbles are prone to rupture under the erosion of high-temperature silicon melt, and the resulting fragments dissolve into the melt, forming impurities and defects that reduce the performance of semiconductor devices. Therefore, reducing the generation and residue of microbubbles during the quartz crucible melting process is crucial for improving crucible quality.

[0003] Existing quartz crucibles mostly employ vacuum arc melting, using graphite electrodes to release a high-temperature electric arc to melt quartz sand raw materials. To reduce microbubbles, the industry typically addresses this from two aspects: raw material purification and process optimization. At the raw material level, methods such as high-temperature chlorination degassing and thermal degassing are used to eliminate gas-liquid inclusions. At the process level, methods such as optimizing electrode placement, controlling vacuum levels, and designing bubble layer structures promote microbubble removal. In existing arc melting processes, simply relying on electrode power to increase temperature results in excessive energy consumption and accelerated electrode wear, with limited room for temperature increases, making it difficult to completely eliminate microbubbles. Summary of the Invention

[0004] In view of the above problems, the present invention provides a method for preparing a quartz crucible and a quartz crucible to solve the above or other problems existing in the prior art.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a method for preparing a quartz crucible, which uses a vacuum arc melting method to prepare the quartz crucible. At the first time point in the arc melting process, while maintaining arc melting, a fluxing step is performed. The fluxing step increases the melting temperature through the exothermic reaction of the flux.

[0006] Furthermore, the fluxing step includes:

[0007] Reaction materials are introduced into the melting zone, and the reaction materials react upon heating to generate flux.

[0008] Monitor the temperature of the melting zone and control the flow rate of the reaction raw materials based on the temperature of the melting zone, so that the temperature of the melting zone is controlled within the target temperature range.

[0009] Furthermore, the flow rate of the reaction raw materials is 0.5-2 L / min.

[0010] Furthermore, when controlling the flow rate of the reactants based on the temperature of the melting zone, the flow rate of the reactants is adjusted based on the comparison between the measured temperature of the melting zone and the target temperature range, including:

[0011] If the temperature of the melting zone is within the target temperature range, the flow rate of the reactants should be kept constant.

[0012] If the temperature in the melting zone is greater than the maximum value of the target temperature, then reduce the flow rate of the reactants.

[0013] If the temperature of the melting zone is less than the minimum target temperature, increase the flow rate of the reactants.

[0014] Furthermore, the target temperature range is 2400℃-2600℃.

[0015] Furthermore, during the fluxing step, the power of the electrode used for arc melting is set as the melting power.

[0016] Furthermore, the reactants are vaporized before being introduced into the melting zone.

[0017] Furthermore, the reaction raw materials are water vapor, and the fluxes are hydrogen and oxygen.

[0018] Furthermore, the first time point is 3-6 minutes before the arc melting stops, and the time for the fluxing step is 1-3 minutes.

[0019] Furthermore, after the fluxing step is completed, a high-temperature holding process is performed, which includes: the power of the electrode used for arc melting is set to maintain a constant melting power for a first time of 1-3 minutes.

[0020] Furthermore, after the high-temperature holding process or the fluxing step is completed, an annealing cooling treatment is performed. The annealing cooling treatment includes: the power of the electrode used for arc melting is set to gradually decrease from the melting power to the minimum power within a second time period of 2-3 minutes.

[0021] A quartz crucible is prepared using the quartz crucible preparation method described above.

[0022] By adopting the above technical solution, the equipment for preparing the quartz crucible is equipped with a reaction material vaporization system. The reaction material vaporization system can vaporize the liquid reaction material into a gaseous reaction material and transport the gaseous reaction material to the vacuum arc melting system. During the arc melting stage, the gaseous reaction material is introduced at an appropriate time. The reaction material is transported to the melting zone and a flux is generated in the melting zone. The flux reacts in the melting zone and releases a large amount of heat. The heat generated by the flux reaction is added to the heat generated by the arc melting, thereby increasing the temperature of the melting zone, increasing the upper limit of the temperature in the vacuum arc melting furnace, reducing the viscosity of the inner surface of the molten quartz sand, and improving the density of the inner surface of the quartz crucible. This can reduce the number of microbubbles inside the transparent layer and inhibit the expansion of microbubbles that damage the inner surface, thus improving the quality of the quartz crucible.

[0023] The gaseous reaction raw material is water vapor, and the flux is hydrogen and oxygen. The hydrogen and oxygen gas generated by the high-temperature decomposition of water vapor enhances combustion efficiency, raising the temperature of the melting zone from 2000-2200℃ to 2400-2600℃ without significantly increasing the electrode power. This increased temperature significantly reduces the viscosity of the molten quartz, promoting the rapid merging, floating, and escape of internal microbubbles. At the same time, the high temperature can eliminate microbubbles, producing a low-microbubble, high-quality quartz crucible. This method breaks through the temperature bottleneck of existing quartz crucible arc melting processes by combining high-temperature decomposition of water vapor with vacuum arc melting to construct a dual heat source system of "arc heating + hydrogen-oxygen combustion supplementary heating," achieving both increased temperature in the melting zone and significant elimination of microbubbles.

[0024] The heat released by the combustion of hydrogen and oxygen supplements the electric arc heating, which can reduce the power of the graphite electrode at the same melting temperature, thereby reducing power consumption and production costs. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of a quartz crucible preparation apparatus according to an embodiment of the present invention;

[0026] Figure 2 This is a schematic diagram of the structure of a vacuum arc melting system according to an embodiment of the present invention;

[0027] Figure 3 This is a schematic diagram of the output pipeline distribution structure according to an embodiment of the present invention.

[0028] In the picture:

[0029] 1. Storage device; 2. Power unit; 3. Shut-off valve; 4. Mass flow meter; 5. Check valve; 6. Vaporization device; 7. Solenoid valve; 8. Output pipeline; 9. Baffle; 10. Graphite mold; 11. Vacuum arc melting furnace; 12. Graphite electrode. Detailed Implementation

[0030] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0031] Figure 1 The diagram shows a structural schematic of an embodiment of the present invention. This embodiment relates to a method for preparing a quartz crucible and a quartz crucible. In the process of preparing a quartz crucible using a vacuum arc melting method, a fluxing step is added to the arc melting stage. The fluxing step is to supplement the arc melting with heat, increase the melting temperature, and improve the density of the inner surface of the quartz crucible. This can reduce the number of microbubbles inside the transparent layer and inhibit the expansion of microbubbles from damaging the inner surface of the quartz crucible.

[0032] An apparatus for preparing a quartz crucible, such as Figure 1-3 As shown, it includes a reaction material vaporization system and a vacuum arc melting system connected to each other. The reaction material vaporization system converts the liquid reaction material into a gaseous state, and the vacuum arc melting system receives the gaseous reaction material. The gaseous reaction material reacts in the vacuum arc melting system to generate a flux. The reaction of the flux generates heat, increases the temperature of the melting zone, accelerates the merging and discharge of microbubbles, and improves the quality of the prepared quartz crucible.

[0033] The reaction material vaporization system provides gaseous reaction materials for the fluxing step within the vacuum arc melting system. This system has an output pipe 8, which directs the reaction material output towards the melting zone of the vacuum arc melting system. This allows the reaction material output from the output pipe 8 to be directly sprayed into the melting zone. The temperature in the melting zone exceeds 2000°C during the arc initiation and termination phases. Under this high-temperature environment, the reaction material decomposes to generate flux. The timing of the reaction material's introduction is controlled to ensure that the reaction material reacts and generates flux in the melting zone. Simultaneously, the flux is exposed to the high-temperature environment of the melting zone... The flux undergoes a combustion reaction under these conditions, releasing a large amount of heat to supplement the heat generated by the arc melting process within the melting zone. This increases the temperature of the melting zone to 2400℃-2600℃, raising the upper temperature limit within the vacuum arc melting furnace 11. It also reduces the viscosity of the inner surface of the molten quartz sand, improving the density of the inner surface of the quartz crucible. This reduces the number of microbubbles inside the transparent layer and inhibits the expansion of microbubbles from damaging the inner surface of the quartz crucible, thus improving the quality of the prepared quartz crucible.

[0034] Specifically, there are multiple output pipes 8, and the number of output pipes 8 is consistent with the number of graphite electrodes 12 in the vacuum arc melting system. The output direction of the reaction material of each output pipe 8 is towards the high-temperature arc zone of the corresponding graphite electrode 12. The reaction material is input from different positions, so that the reaction material enters the melting area quickly and evenly, making full use of the temperature of the high-temperature arc zone of the graphite electrode 12, thereby uniformly increasing the temperature of the melting area.

[0035] The aforementioned vacuum arc melting system uses a vacuum arc melting method to prepare quartz crucibles. Therefore, this system includes a vacuum arc melting furnace 11, a graphite mold 10 disposed within the furnace 11, a graphite electrode 12, and a vacuum system. The graphite electrode 12 generates an electric arc, which melts the quartz sand under negative pressure using a high-temperature arc. With the aid of the graphite mold 10 and vacuum technology, a quartz crucible with a double-layer structure consisting of a transparent layer and a microbubble composite layer is formed in one step. The specific structure of this vacuum arc melting system is existing technology and will not be described in detail here.

[0036] The above-mentioned reaction material vaporization system includes a raw material conveying branch, a gas conveying branch, and a vaporization device 6. Both the raw material conveying branch and the gas conveying branch are connected to the vaporization device 6. The vaporization device 6 is connected to multiple output pipelines 8. The raw material conveying branch and the gas conveying branch respectively convey liquid reaction materials and gas to the vaporization device 6. The liquid reaction materials are vaporized into gaseous reaction materials in the vaporization device 6, and the gaseous reaction materials are output through the output pipelines 8. The raw material conveying branch is designed for the continuous conveying of liquid reactants, thereby enabling the continuous conveying of gaseous reactants via the vaporization device 6. The gas conveying branch continuously supplies gas to the vaporization device 6; this gas acts as a carrier gas, reducing the partial pressure of the liquid reactants during vaporization into gaseous reactants within the vaporization device 6, thus promoting the evaporation of the liquid reactants. The vaporization device 6 is designed to convert the liquid reactants into gaseous reactants, which are then vaporized within the vaporization device 6 to form gaseous reactants, thus providing gaseous reactants for the vacuum arc melting system.

[0037] The aforementioned raw material transport branch includes a storage device 1 and a power unit 2. The power unit 2 is connected to both the storage device 1 and the vaporization device 6 via pipelines. The storage device 1 contains liquid reactants, and the power unit 2 provides power for the flow of the liquid reactants. When the power unit 2 operates, it transports the liquid reactants from the storage device 1 to the vaporization device 6. The storage device 1 is connected to an external source of liquid reactants via pipelines, and the external source continuously supplies liquid reactants to the storage device 1.

[0038] The aforementioned storage device 1 is a box or tank structure with internal space for temporary storage of liquid reaction raw materials. The appropriate storage box / tank can be selected based on actual needs; specific requirements are not specified here.

[0039] The aforementioned power unit 2 is a pump, which can be a positive displacement pump or a vane pump. These are commercially available products. The appropriate type of pump should be selected according to actual needs, and no specific requirements are specified here.

[0040] The liquid reaction raw material mentioned above is deionized water, and the gaseous reaction raw material is water vapor; or, the liquid reaction raw material mentioned above is hydrogen peroxide, and the gaseous reaction raw material is gaseous hydrogen peroxide.

[0041] The aforementioned gas delivery branch includes a delivery pipeline and a shut-off valve 3, a mass flow meter 4, and a check valve 5 installed on the delivery pipeline. The delivery pipeline is connected to the vaporization device 6, and the other end of the delivery pipeline is connected to a gas source, which provides gas. The gas is delivered along the delivery pipeline to the vaporization device 6, achieving continuous gas delivery. Along the direction of gas delivery, the shut-off valve 3, mass flow meter 4, and check valve 5 are sequentially installed on the delivery pipeline. The shut-off valve 3 cuts off and throttles the gas flowing in the delivery pipeline, controlling the opening and closing of the delivery pipeline and controlling whether the gas enters the vaporization device 6. The mass flow meter 4 monitors the mass flow rate of the gas in the delivery pipeline, facilitating the control of the mass of the gas entering the vaporization device 6. The check valve 5 ensures that the gas can only enter the vaporization device 6, and the gaseous reaction raw materials generated in the vaporization device 6 cannot enter the delivery pipeline, thus restricting and controlling the gas flow direction.

[0042] The aforementioned shut-off valve 3, mass flow meter 4, and check valve 5 are all commercially available products. They can be selected and set according to actual needs, and no specific requirements are specified here.

[0043] The gas mentioned above is air.

[0044] The vaporization device 6 mentioned above is an evaporator, which can convert liquid reaction raw materials into gaseous reaction raw materials. It is a commercially available product and can be selected according to actual needs. No specific requirements are made here.

[0045] The aforementioned output pipe 8 is a pipe structure, and there are multiple output pipes 8. Multiple output pipes 8 can be connected to the vaporization device 6 at the same time. The gaseous reaction raw materials output by the vaporization device 6 can enter each output pipe 8 respectively. Alternatively, multiple output pipes 8 can be connected to the vaporization device 6 through a main pipe, and the gaseous reaction raw materials output by the vaporization device 6 can enter each output pipe 8 respectively through the main pipe.

[0046] The output pipeline 8 is equipped with a switch device. The switch device controls the opening and closing of the output pipeline 8, controls whether the gaseous reaction raw material enters the vacuum arc melting system, and controls the flow direction, flow rate, and flow velocity of the gaseous reaction raw material.

[0047] The aforementioned switching device is solenoid valve 7, which is a commercially available product. It can be selected and set according to actual needs, and no specific requirements are specified here.

[0048] According to the working principle of the evaporator, the reaction material output from the output pipe 8 is a mixture of gaseous reaction material and air. That is, what enters the vacuum arc melting system is gaseous reaction material and air. Since there is air in the vacuum arc melting furnace 11, the air that enters the vacuum arc melting furnace 11 with the gaseous reaction material will not affect the quality of the quartz crucible.

[0049] As described above, the structure of the vacuum arc melting system is as follows: In order to enable the output pipe 8 to enter the vacuum arc melting system and directly transport the gaseous reaction raw materials to the melting area, the vacuum arc melting system also includes a baffle 9 and a graphite mold 10. The baffle 9 is located above the graphite mold 10 and has multiple through holes. The output pipe 8 extends through the through holes to the top of the graphite mold 10. The number of through holes is consistent with the number of output pipes 8. Each through hole allows one output pipe 8 to pass through, avoiding interference between the output pipe 8 and the baffle 9. At the same time, it positions and fixes the installation position of the output pipe 8 in the vacuum arc melting furnace 11.

[0050] The aforementioned baffle 9 is a plate structure with a flow channel inside. The baffle 9 is connected to an external coolant supply structure via a cooling pipe. The coolant supply structure provides coolant to the baffle 9, giving it a heat insulation function. This isolates the high temperature of the arc melting zone within the vacuum arc melting furnace 11 to the area below the baffle 9, keeping the temperature above the baffle 9 lower and preventing interference with the normal operation of electrodes and other components located above the baffle 9. Through holes are formed along the thickness direction of the baffle 9, with multiple through holes arranged circumferentially. The shape of these through holes is adapted to the shape of the output pipe 8, allowing the output pipe 8 to pass through the through holes onto the baffle 9. The through holes can be sealed to prevent coolant leakage from the baffle 9.

[0051] To further optimize the design, the vacuum arc melting system also includes a temperature detection device. This device is located on the vacuum arc melting furnace 11 and monitors the temperature of the melting zone. Based on this temperature, the input flow rate of the gaseous reaction materials is controlled, ensuring the temperature of the melting zone remains stable within the target range. This temperature detection device can be an infrared thermometer or an infrared thermal imager, both commercially available products. The selection and configuration are based on actual needs and are not specified here.

[0052] The equipment for preparing the quartz crucible also includes a control device, which is connected to both the reaction material vaporization system and the vacuum arc melting system, controlling their operation. Specifically, the control device is electrically connected to the power unit 2, the shut-off valve 3, the mass flow meter 4, the vaporization device 6, the solenoid valve 7, and the temperature detection device. The control device receives detection signals from the mass flow meter 4 and the temperature detection device, processes and judges these signals, and controls the operation of the power unit 2, the shut-off valve 3, the vaporization device 6, and the solenoid valve 7 to control the flow rate of the gaseous reaction material.

[0053] When using this quartz crucible preparation equipment, the shut-off valve 3 is opened, and the liquid reaction material in the storage device 1 enters the vaporization device 6 under the action of the power device 2. Simultaneously, gas enters the vaporization device 6 through a conveying pipe. The liquid reaction material vaporizes into gaseous reaction material in the vaporization device 6. The gaseous reaction material and gas flow along the output pipe 8 and are output into the vacuum arc melting system, sprayed into the melting area. The gaseous reaction material reacts in the melting area to generate flux. The flux undergoes a melting process, releasing a large amount of heat and raising the temperature of the melting area. During the reaction of the gaseous reaction material in the melting area, the temperature detection device monitors the temperature of the melting area and sends the detected temperature signal to the control device. The control device controls the solenoid valve 7 based on the temperature signal, controlling the flow rate and duration of the gaseous reaction material, thereby regulating the temperature of the melting area.

[0054] A method for preparing a quartz crucible involves using the aforementioned equipment and employing a vacuum arc melting method. During the arc melting process, a fluxing step is performed simultaneously with the arc melting at the first time point. The fluxing step releases heat through the reaction of the flux, increasing the melting temperature based on the heat generated by the arc melting, thus providing additional heat for the arc melting. This reduces the viscosity of the inner surface of the molten quartz sand and improves the density of the inner surface of the quartz crucible. This reduces the number of microbubbles inside the transparent layer and inhibits the expansion of microbubbles from damaging the inner surface of the quartz crucible.

[0055] This vacuum arc melting method includes sequential steps of loading and forming, vacuuming, arc melting, cooling and demolding, and post-processing. The raw material, quartz sand, is prepared into a quartz crucible. This crucible has a transparent layer and a microbubble composite layer disposed outside the transparent layer. During the arc melting stage, the graphite electrode 12 initiates an arc, generating high heat, which melts the quartz sand. During the arc melting stage, the temperature of the graphite electrode 12 can rise to over 2000℃ in both the arc initiation and termination stages, meeting the reaction requirements of the flux. The flux reacts at this temperature, releasing a large amount of heat, further increasing the temperature of the melting zone.

[0056] The first time point mentioned above is 3-6 minutes before the arc melting stops. That is, during the arc melting stage, as the arc melting proceeds, a fluxing step is performed 3-6 minutes before the arc melting ends. The fluxing step is performed at the same time as the arc melting. The heat generated by the two processes is superimposed, thereby increasing the temperature of the melting area.

[0057] When the fluxing step is implemented, the fluxing step lasts for 1-3 minutes. That is, the fluxing step lasts for 1-3 minutes. The duration of the fluxing step can be 1 minute, 2 minutes, 3 minutes, or any time within 1-3 minutes. It can be selected and set according to actual needs. No specific requirements are made here.

[0058] Specifically, the above-mentioned fluxing steps include:

[0059] The reactant is introduced into the melting zone. The reactant reacts upon heating to generate flux. The reactant is gaseous and enters the melting zone directly. Since the gaseous reactant is introduced 3-6 minutes before the arc is stopped, it is in the final stage of the arc melting process. At this time, the temperature of the melting zone is above 2000℃. Therefore, the gaseous reactant decomposes under high temperature and generates flux.

[0060] In some feasible embodiments, the above-mentioned reaction raw material is water vapor. The high temperature conditions above 2000°C meet the conditions for water vapor decomposition. Water vapor decomposes upon heating to generate hydrogen (H2) and oxygen (O2), and the reaction formula is: 2H2O (high temperature 2000°C) = 2H2↑ + O2↑; therefore, the flux is hydrogen and oxygen.

[0061] Hydrogen is flammable, and oxygen is combustion-supporting. The conditions for hydrogen and oxygen to undergo a combustion reaction are 450℃-600℃. Therefore, hydrogen and oxygen undergo a combustion reaction at a high temperature of 2000℃ to produce water. The water produced is pumped to the outside of the vacuum arc melting furnace 11 by the vacuum system of the vacuum arc melting furnace 11. This will not affect the stability of the arc of the graphite electrode 12, nor will it affect the quality of the quartz crucible. Hydrogen and oxygen undergo a combustion reaction, releasing a large amount of heat to supplement the electric arc melting process and increase the temperature of the melting zone. This raises the upper temperature limit within the vacuum electric arc melting furnace 11, allowing the melting zone temperature to reach 2400℃-2600℃. Under this high-temperature environment, the viscosity of the melt formed by the melting of quartz sand on the inner wall of the graphite mold 10 decreases, and the microbubbles encased inside rapidly merge and float to the surface. Simultaneously, the airflow generated by the combustion of hydrogen and oxygen disturbs the surface of the melt, accelerating the escape of microbubbles. In other words, the increase in temperature in the melting zone accelerates the discharge of microbubbles from the transparent layer of the quartz crucible. The microbubbles escape into the negative pressure environment within the vacuum electric arc melting furnace 11 and are then removed by the vacuum system, reducing the number of microbubbles inside the transparent layer. Since the microbubbles escape directly, their expansion and damage to the inner surface are suppressed.

[0062] By adding a fluxing step to the electric arc melting process, the temperature of the melting zone is increased. The electric arc melting and fluxing steps are carried out simultaneously. Therefore, during the fluxing step, the vacuum system in the vacuum arc melting furnace 11 continues to work, and a negative pressure environment is maintained inside the vacuum arc melting furnace 11. This negative pressure environment refers to the negative pressure inside the furnace, which controls the movement of microbubbles in the transparent layer to the bubble composite layer, thereby reducing the number of microbubbles in the transparent layer. Therefore, when the above-mentioned quartz crucible preparation equipment is used to implement this quartz crucible preparation method, the reaction raw materials are vaporized before being introduced into the melting zone, converting the liquid reaction raw materials into gaseous reaction raw materials. The gaseous reaction raw materials directly decompose in the melting zone to generate flux, omitting the endothermic process in the vaporization of liquid reaction raw materials into gaseous reaction raw materials.

[0063] The flow rate of the above-mentioned reaction raw materials is 0.5-2 L / min. This flow rate can be any flow rate value within the range of 0.5-2 L / min, such as 0.5 L / min, 1 L / min, 1.5 L / min, or 2 L / min. It can be selected and set according to actual needs, and no specific requirements are specified here.

[0064] During the fluxing step, gaseous reaction materials are continuously introduced and the melting state is maintained for 1-3 minutes. During this time, the temperature of the melting zone is maintained at 2400℃-2600℃ to ensure that the microbubbles in the transparent layer can be completely expelled.

[0065] During the continuous feeding of gaseous reactants, the temperature of the melting zone is monitored, and the feed rate is controlled based on this temperature to maintain it within the target range of 2400℃-2600℃. Maintaining the temperature within this range effectively reduces the viscosity of the molten quartz sand, improving the density of the crucible's inner surface. This reduces the number of microbubbles within the transparent layer and inhibits their expansion, which can damage the inner surface, thus lowering electrode energy consumption and wear. If the melting zone temperature is below 2400℃, the quartz sand will over-melt, resulting in excessive fluidity and preventing the crucible from holding its shape. Conversely, if the temperature exceeds 2600℃, the quartz sand will not melt completely, leaving impurities unremoved and affecting the crucible's quality, ultimately failing to meet requirements.

[0066] When controlling the flow rate of the reactants based on the temperature of the melting zone, the flow rate is adjusted according to the comparison between the measured temperature of the melting zone and the target temperature range. Specifically, the temperature detection device monitors the temperature of the melting zone in real time, compares the detected temperature with the preset target temperature range, determines the relationship between the detected temperature and the target temperature range, and adjusts the flow rate of the reactants based on this relationship. This includes:

[0067] If the temperature of the melting zone is within the target temperature range, the flow rate of the reactant should be kept constant. That is, when the detected temperature of the melting zone is within the range of 2400℃-2600℃, it means that the temperature of the melting zone meets the reaction requirements of the reactant, the reaction requirements of the flux, and the quality of the quartz crucible can also be guaranteed. The flow rate of the reactant does not need to be adjusted.

[0068] If the temperature of the melting zone is greater than the maximum value of the target temperature, the flow rate of the reactants should be reduced. That is, when the detected temperature of the melting zone is greater than 2600℃, the detected temperature of the melting zone exceeds the target temperature range. At this time, cooling is required to reduce the heat released by the flux reaction, reduce the amount of flux, and reduce the flow rate of the reactants.

[0069] If the temperature of the melting zone is less than the minimum target temperature, the flow rate of the reaction raw materials should be increased. That is, when the detected temperature of the melting zone is less than 2400℃, the detected temperature of the melting zone exceeds the target temperature range. At this time, it is necessary to raise the temperature, increase the heat released by the flux reaction, increase the amount of flux, and increase the flow rate of the reaction raw materials.

[0070] When the flow rate of the reaction raw materials is increased or decreased, the flow rate can be increased or decreased by a flow rate change of 0.1-0.5 L / min. This flow rate change can be any flow rate value within the range of 0.1-0.5 L / min, such as 0.1 L / min, 0.2 L / min, 0.3 L / min, 0.4 L / min, or 0.5 L / min. It can be selected and set according to actual needs, and no specific requirements are specified here.

[0071] During the fluxing process, arc melting is also underway. In this process, the power of the electrode used for arc melting is set as the melting power, which is controlled by the melting current. The melting current is 5000A-6000A, and the magnitude of the melting current can be selected and set according to actual needs. No specific requirements are specified here.

[0072] Before the fluxing step, during the arc melting process, the power of the electrode used for electroplating is set to the melting power. That is, in the melting stage before the fluxing step and in the melting stage that is carried out simultaneously with the fluxing step, the power of the electrode remains unchanged and is the melting power. The heat generated during the arc melting process remains unchanged. The fluxing step effectively increases the temperature of the melting area and allows the temperature of the melting area to be adjusted within the target temperature range, ensuring that the temperature of the melting area is controllable.

[0073] In some feasible embodiments, the reaction raw material described above may also be gaseous hydrogen peroxide.

[0074] Further optimization of the scheme involves a high-temperature holding process after the fluxing step. This process includes: setting the power of the electrode used for arc melting to remain constant for the first time; high-temperature polishing of the inner wall of the quartz crucible; and smoothing the inner surface damaged by microbubble expansion. This ensures that the uniformity of the quartz crucible wall thickness and the smoothness of the inner wall surface meet design requirements, thereby guaranteeing the quality of the quartz crucible. This high-temperature holding process ensures that the arc melting process continues after the fluxing step, with the electrode power being the melting power during this process.

[0075] The first time mentioned above is 1-3 minutes. This first time can be 1 minute, 2 minutes, 3 minutes, or any time within 1-3 minutes. It can be selected and set according to actual needs. No specific requirements are made here.

[0076] To further optimize the process, an annealing and cooling treatment is performed after the high-temperature holding process or the fluxing step to eliminate internal stress in the quartz crucible. This annealing and cooling treatment can be performed after the fluxing step, meaning the arc melting stage ends simultaneously with the fluxing step; or, it can be performed after the high-temperature holding process, meaning that during the arc melting stage, the fluxing step and the high-temperature holding process are performed sequentially and synchronously before the arc melting ends, and the arc melting stage ends simultaneously with the high-temperature holding process, followed by the annealing and cooling treatment. The timing of this annealing and cooling treatment can be selected according to actual needs.

[0077] The aforementioned annealing cooling process includes: the power of the electrode used for arc melting is set to gradually decrease from the melting power to a minimum power within a second time period. The electrode power is controlled by current, and as the electrode power gradually decreases from the melting power to the minimum power, the electrode current gradually decreases from the melting current to the minimum current. Here, the minimum power is 0, and correspondingly, the minimum current is also 0.

[0078] The second time mentioned above is 2-3 minutes. This second time can be selected and set according to actual needs, and no specific requirements are made here.

[0079] When the annealing and cooling process is finished, the temperature inside the vacuum arc melting furnace 11 drops to 1100-1300℃, and the temperature of the quartz crucible is also relatively high. After the temperature of the quartz crucible cools down to room temperature, the quartz crucible is taken out, and the preparation of the quartz crucible is completed.

[0080] A quartz crucible, prepared using the quartz crucible preparation method described above, wherein the density of microbubbles within 1 mm of the transparent layer at the upper edge of the quartz crucible is 0.2-0.9 bubbles / mm. 2 The density of microbubbles within 1 mm of the transparent layer at the bottom of the quartz crucible is 0.1-0.7 per mm. 2 The density of microbubbles within 1 mm of the transparent layer at the radius (R-corner) of the quartz crucible is 0.02-0.3 bubbles / mm. 2 .

[0081] Here, the upper edge refers to the position 4cm above the upper edge of the quartz crucible (the edge of the quartz crucible opening), which is the position of the liquid level line. The lower edge refers to the position 10cm above the upper edge of the quartz crucible. The R angle refers to the position of the arc angle of the quartz crucible.

[0082] The following detailed description uses some specific embodiments.

[0083] Example 1

[0084] A method for preparing a quartz crucible, employing vacuum arc melting and a fluxing step, primarily using vacuum arc melting, supplemented by a fluxing step at appropriate times to increase the temperature of the melting zone, includes the following steps:

[0085] Quartz sand is loaded into the graphite mold 10, and the vacuum arc melting furnace 11 is evacuated to make the inside of the vacuum arc melting furnace 11 a negative pressure state.

[0086] The graphite electrode 12 is used to initiate an arc for arc melting. The power of the graphite electrode 12 is the melting power, and the melting current is 5500A.

[0087] Entering the final stage of arc melting, 6 minutes before the arc is stopped, a fluxing step is performed by introducing steam into the melting area at a flow rate of 0.5 L / min for 60 seconds.

[0088] During the steam introduction process, the temperature of the melting zone is monitored, and the steam flow rate is controlled according to the monitored temperature to keep the temperature of the melting zone between 2400-2600℃.

[0089] During the fluxing step, the power of the graphite electrode is the melting power. After the fluxing step is completed, a high-temperature holding process is performed, during which the power of the graphite electrode is the melting power, and the high-temperature holding process lasts for 60 seconds.

[0090] After the high-temperature holding process is completed, the arc melting process ends, and annealing and cooling treatment is carried out. Within 2 minutes, the power of the graphite electrode is reduced from the melting power to 0.

[0091] After the quartz crucible has cooled to room temperature, remove it to complete the preparation of the quartz crucible.

[0092] The microbubble density of the transparent layer of the quartz crucible was measured at depths of 0.5 mm and 1 mm at the top, 0.5 mm and 1 mm at the bottom, and 0.5 mm and 1 mm at the radius (R-angle). The unit of microbubble density is microbubble count per square millimeter. The measured data are shown in Table 1 below. The comparative example is a quartz crucible prepared using existing technology.

[0093] Table 1

[0094]

[0095] As shown in Table 1, the number of microbubbles in the transparent layer of the quartz crucible prepared by the method of this embodiment is significantly reduced compared with the number of microbubbles in the transparent layer of the quartz crucible prepared by the existing method.

[0096] Example 2

[0097] A method for preparing a quartz crucible, employing vacuum arc melting and a fluxing step, primarily using vacuum arc melting, supplemented by a fluxing step at appropriate times to increase the temperature of the melting zone, includes the following steps:

[0098] Quartz sand is loaded into the graphite mold 10, and the vacuum arc melting furnace 11 is evacuated to make the inside of the vacuum arc melting furnace 11 a negative pressure state.

[0099] The graphite electrode 12 is used to initiate an arc for arc melting. The power of the graphite electrode 12 is the melting power, and the melting current is 5500A.

[0100] Entering the final stage of electric arc melting, 6 minutes before the electric arc is stopped, a fluxing step is performed by introducing steam into the melting area at a flow rate of 1L / min for 120s.

[0101] During the steam introduction process, the temperature of the melting zone is monitored, and the steam flow rate is controlled according to the monitored temperature to keep the temperature of the melting zone between 2400-2600℃.

[0102] During the fluxing step, the power of the graphite electrode is the melting power. After the fluxing step is completed, a high-temperature holding process is performed, during which the power of the graphite electrode is the melting power, and the high-temperature holding process lasts for 120 seconds.

[0103] After the high-temperature holding process is completed, the arc melting process ends, and annealing and cooling treatment is carried out. Within 2 minutes, the power of the graphite electrode is reduced from the melting power to 0.

[0104] After the quartz crucible has cooled to room temperature, remove it to complete the preparation of the quartz crucible.

[0105] The microbubble density of the transparent layer of the quartz crucible was measured at depths of 0.5 mm and 1 mm at the top, 0.5 mm and 1 mm at the bottom, and 0.5 mm and 1 mm at the radius (R-angle). The unit of microbubble density is microbubble count per square millimeter. The measured data are shown in Table 2 below. The comparative example is a quartz crucible prepared using existing technology.

[0106] Table 2

[0107]

[0108] As shown in Table 2, the number of microbubbles in the transparent layer of the quartz crucible prepared by the method of this embodiment is significantly reduced compared with the number of microbubbles in the transparent layer of the quartz crucible prepared by the existing method.

[0109] Example 3

[0110] A method for preparing a quartz crucible, employing vacuum arc melting and a fluxing step, primarily using vacuum arc melting, supplemented by a fluxing step at appropriate times to increase the temperature of the melting zone, includes the following steps:

[0111] Quartz sand is loaded into the graphite mold 10, and the vacuum arc melting furnace 11 is evacuated to make the inside of the vacuum arc melting furnace 11 a negative pressure state.

[0112] The graphite electrode 12 is used to initiate an arc for arc melting. The power of the graphite electrode 12 is the melting power, and the melting current is 5500A.

[0113] Entering the final stage of electric arc melting, 6 minutes before the arc is stopped, a fluxing step is performed by introducing steam into the melting area at a flow rate of 1.5 L / min for 150 seconds.

[0114] During the steam introduction process, the temperature of the melting zone is monitored, and the steam flow rate is controlled according to the monitored temperature to keep the temperature of the melting zone between 2400-2600℃.

[0115] During the fluxing step, the power of the graphite electrode is the melting power. After the fluxing step is completed, a high-temperature holding process is performed, during which the power of the graphite electrode is the melting power, and the high-temperature holding process lasts for 150 seconds.

[0116] After the high-temperature holding process is completed, the arc melting process ends, and annealing and cooling treatment is carried out. Within 2 minutes, the power of the graphite electrode is reduced from the melting power to 0.

[0117] After the quartz crucible has cooled to room temperature, remove it to complete the preparation of the quartz crucible.

[0118] The microbubble density of the transparent layer of the quartz crucible was measured at depths of 0.5 mm and 1 mm at the top, 0.5 mm and 1 mm at the bottom, and 0.5 mm and 1 mm at the radius (R-angle). The unit of microbubble density is microbubble count per square millimeter. The measured data are shown in Table 3 below. The comparative example is a quartz crucible prepared using existing technology.

[0119] Table 3

[0120]

[0121] As shown in Table 3, the number of microbubbles in the transparent layer of the quartz crucible prepared by the method of this embodiment is significantly reduced compared with the number of microbubbles in the transparent layer of the quartz crucible prepared by the existing method.

[0122] Example 4

[0123] A method for preparing a quartz crucible, employing vacuum arc melting and a fluxing step, primarily using vacuum arc melting, supplemented by a fluxing step at appropriate times to increase the temperature of the melting zone, includes the following steps:

[0124] Quartz sand is loaded into the graphite mold 10, and the vacuum arc melting furnace 11 is evacuated to make the inside of the vacuum arc melting furnace 11 a negative pressure state.

[0125] The graphite electrode 12 is used to initiate an arc for arc melting. The power of the graphite electrode 12 is the melting power, and the melting current is 5500A.

[0126] Entering the final stage of arc melting, 6 minutes before the arc melting is stopped, a fluxing step is performed, in which steam is introduced into the melting area at a flow rate of 2L / min for 180s.

[0127] During the steam introduction process, the temperature of the melting zone is monitored, and the steam flow rate is controlled according to the monitored temperature to keep the temperature of the melting zone between 2400-2600℃.

[0128] During the fluxing step, the power of the graphite electrode is the melting power. After the fluxing step is completed, a high-temperature holding process is performed, during which the power of the graphite electrode is the melting power, and the high-temperature holding process lasts for 180 seconds.

[0129] After the high-temperature holding process is completed, the arc melting process ends, and annealing and cooling treatment is carried out. Within 2 minutes, the power of the graphite electrode is reduced from the melting power to 0.

[0130] After the quartz crucible has cooled to room temperature, remove it to complete the preparation of the quartz crucible.

[0131] The microbubble density of the transparent layer of the quartz crucible was measured at depths of 0.5 mm and 1 mm at the top, 0.5 mm and 1 mm at the bottom, and 0.5 mm and 1 mm at the radius (R-angle). The unit of microbubble density is microbubble count per square millimeter. The measured data are shown in Table 4 below. The comparative example is a quartz crucible prepared using existing technology.

[0132] Table 4

[0133]

[0134] As shown in Table 4, the number of microbubbles in the transparent layer of the quartz crucible prepared by the method of this embodiment is significantly reduced compared with the number of microbubbles in the transparent layer of the quartz crucible prepared by the existing method.

[0135] Example 5

[0136] A method for preparing a quartz crucible, employing vacuum arc melting and a fluxing step, primarily using vacuum arc melting, supplemented by a fluxing step at appropriate times to increase the temperature of the melting zone, includes the following steps:

[0137] Quartz sand is loaded into the graphite mold 10, and the vacuum arc melting furnace 11 is evacuated to make the inside of the vacuum arc melting furnace 11 a negative pressure state.

[0138] The graphite electrode 12 is used to initiate an arc for arc melting. The power of the graphite electrode 12 is the melting power, and the melting current is 5500A.

[0139] Entering the final stage of electric arc melting, 6 minutes before the electric arc is stopped, a fluxing step is performed by introducing steam into the melting area at a flow rate of 1L / min for 150s.

[0140] During the steam introduction process, the temperature of the melting zone is monitored, and the steam flow rate is controlled according to the monitored temperature to keep the temperature of the melting zone between 2400-2600℃.

[0141] During the fluxing step, the power of the graphite electrode is the melting power. After the fluxing step is completed, a high-temperature holding process is performed, during which the power of the graphite electrode is the melting power, and the high-temperature holding process lasts for 120 seconds.

[0142] After the high-temperature holding process is completed, the arc melting process ends, and annealing and cooling treatment is carried out. Within 2 minutes, the power of the graphite electrode is reduced from the melting power to 0.

[0143] After the quartz crucible has cooled to room temperature, remove it to complete the preparation of the quartz crucible.

[0144] The microbubble density of the transparent layer of the quartz crucible was measured at depths of 0.5 mm and 1 mm at the top, 0.5 mm and 1 mm at the bottom, and 0.5 mm and 1 mm at the radius (R-angle). The unit of microbubble density is microbubble count per square millimeter. The measured data are shown in Table 5 below. The comparative example is a quartz crucible prepared using existing technology.

[0145] Table 5

[0146]

[0147] As shown in Table 5, the number of microbubbles in the transparent layer of the quartz crucible prepared by the method of this embodiment is significantly reduced compared with the number of microbubbles in the transparent layer of the quartz crucible prepared by the existing method.

[0148] Example 6

[0149] A method for preparing a quartz crucible, employing vacuum arc melting and a fluxing step, primarily using vacuum arc melting, supplemented by a fluxing step at appropriate times to increase the temperature of the melting zone, includes the following steps:

[0150] Quartz sand is loaded into the graphite mold 10, and the vacuum arc melting furnace 11 is evacuated to make the inside of the vacuum arc melting furnace 11 a negative pressure state.

[0151] The graphite electrode 12 is used to initiate an arc for arc melting. The power of the graphite electrode 12 is the melting power, and the melting current is 5500A.

[0152] Entering the final stage of electric arc melting, 6 minutes before the arc is stopped, a fluxing step is performed by introducing steam into the melting area at a flow rate of 0.3 L / min for 40 seconds.

[0153] During the steam introduction process, the temperature of the melting zone is monitored, and the steam flow rate is controlled according to the monitored temperature to keep the temperature of the melting zone between 2400-2600℃.

[0154] During the fluxing step, the power of the graphite electrode is the melting power. After the fluxing step is completed, a high-temperature holding process is performed, during which the power of the graphite electrode is the melting power, and the high-temperature holding process lasts for 40 seconds.

[0155] After the high-temperature holding process is completed, the arc melting process ends, and annealing and cooling treatment is carried out. Within 2 minutes, the power of the graphite electrode is reduced from the melting power to 0.

[0156] After the quartz crucible has cooled to room temperature, remove it to complete the preparation of the quartz crucible.

[0157] The microbubble density of the transparent layer of the quartz crucible was measured at depths of 0.5 mm and 1 mm at the top, 0.5 mm and 1 mm at the bottom, and 0.5 mm and 1 mm at the radius (R-angle). The unit of microbubble density is microbubble count per square millimeter. The measured data are shown in Table 6 below. The comparative example is a quartz crucible prepared using existing technology.

[0158] Table 6

[0159]

[0160] As shown in Table 6, the number of microbubbles in the transparent layer of the quartz crucible prepared by the method of this embodiment is reduced compared with the number of microbubbles in the transparent layer of the quartz crucible prepared by the existing method.

[0161] Example 7

[0162] A method for preparing a quartz crucible, employing vacuum arc melting and a fluxing step, primarily using vacuum arc melting, supplemented by a fluxing step at appropriate times to increase the temperature of the melting zone, includes the following steps:

[0163] Quartz sand is loaded into the graphite mold 10, and the vacuum arc melting furnace 11 is evacuated to make the inside of the vacuum arc melting furnace 11 a negative pressure state.

[0164] The graphite electrode 12 is used to initiate an arc for arc melting. The power of the graphite electrode 12 is the melting power, and the melting current is 5500A.

[0165] Entering the final stage of arc melting, 6 minutes before the arc melting is stopped, a fluxing step is performed by introducing steam into the melting area at a flow rate of 2.3 L / min for 210 seconds.

[0166] During the steam introduction process, the temperature of the melting zone is monitored, and the steam flow rate is controlled according to the monitored temperature to keep the temperature of the melting zone between 2400-2600℃.

[0167] During the fluxing step, the power of the graphite electrode is the melting power. After the fluxing step is completed, a high-temperature holding process is performed, during which the power of the graphite electrode is the melting power, and the high-temperature holding process lasts for 210 seconds.

[0168] After the high-temperature holding process is completed, the arc melting process ends, and annealing and cooling treatment is carried out. Within 2 minutes, the power of the graphite electrode is reduced from the melting power to 0.

[0169] After the quartz crucible has cooled to room temperature, remove it to complete the preparation of the quartz crucible.

[0170] The microbubble density of the transparent layer of the quartz crucible was measured at depths of 0.5 mm and 1 mm at the top, 0.5 mm and 1 mm at the bottom, and 0.5 mm and 1 mm at the radius (R-angle). The unit of microbubble density is microbubble count per square millimeter. The measured data are shown in Table 7 below. The comparative example is a quartz crucible prepared using existing technology.

[0171] Table 7

[0172]

[0173] As shown in Table 7, the number of microbubbles in the transparent layer of the quartz crucible prepared by the method of this embodiment is significantly reduced compared with the number of microbubbles in the transparent layer of the quartz crucible prepared by the existing method.

[0174] The detection data of microbubble density in the transparent layer of the quartz crucibles prepared in the above seven embodiments and the preparation conditions were statistically analyzed, as shown in Table 8 below:

[0175] Table 8.7 Data on the Measurement of Microbubble Density in the Transparent Layer of the Quartz Crucible in Examples

[0176]

[0177] In Tables 1-8 above, the upper edge refers to the position 4 cm above the upper edge of the quartz crucible (the edge of the quartz crucible opening), which is the position of the liquid level line. The lower opening refers to the position 10 cm above the upper edge of the quartz crucible. The R angle refers to the position of the arc angle of the quartz crucible. The measured data is the number of microbubbles per unit area at two depths (0.5 mm and 1 mm) at a point, with the unit being the number of microbubbles per square millimeter.

[0178] The data measurements in Tables 1-8 above were taken using a microbubble detector at room temperature, with a lens area of ​​16.2 square millimeters.

[0179] In Tables 1-8 above, the comparative examples are quartz crucibles prepared using existing processes, which do not include a fluxing step in the preparation of quartz crucibles.

[0180] As shown in Table 8 above, the number of microbubbles in the transparent layer of the quartz crucible prepared by the above-described method is significantly reduced compared to the number of microbubbles in the transparent layer of the quartz crucible prepared by existing methods, thus improving the quality of the quartz crucible. Furthermore, the number of microbubbles gradually decreases with increasing steam flow rate and flow time. Within the same flow time, the number of microbubbles gradually decreases with increasing steam flow rate, and similarly, with the same steam flow rate, the number of microbubbles gradually decreases with increasing flow time.

[0181] The data from experiments 6 and 7 show that when the steam flow rate is less than 0.5 L / min and the flow time is less than 1 min, the number of microbubbles in the quartz crucible is relatively high, exceeding the design requirements. When the steam flow rate is greater than 2 L / min and the flow time is greater than 3 min, the reduction in the number of microbubbles in the quartz crucible is small, which reduces production efficiency. Therefore, during the fluxing step, controlling the steam flow rate between 0.5 and 2 L / min and the flow time between 1 and 3 min satisfies both production efficiency and the design requirements for the number of microbubbles in the prepared quartz crucible, thus improving the quality of the quartz crucible.

[0182] Due to the adoption of the above technical solution, the equipment for preparing the quartz crucible is equipped with a reaction material vaporization system. This system vaporizes liquid reaction materials into gaseous reaction materials and transports them to the vacuum arc melting system. During the arc melting stage, the gaseous reaction materials are introduced at an appropriate time. The reaction materials are transported to the melting zone, where a flux is generated. The flux reacts in the melting zone, releasing a large amount of heat. This heat, combined with the heat generated by the flux reaction, increases the temperature of the melting zone, raising the upper temperature limit of the vacuum arc melting furnace. This reduces the viscosity of the inner surface of the molten quartz sand and improves the density of the inner surface of the quartz crucible. This reduces the number of microbubbles inside the transparent layer and inhibits the expansion of microbubbles that could damage the inner surface, thus improving the quality of the quartz crucible. The gaseous reaction material is water. The process utilizes steam and hydrogen and oxygen as fluxes. The hydrogen and oxygen gases produced by the high-temperature decomposition of steam enhance combustion efficiency, raising the melting zone temperature from 2000-2200℃ to 2400-2600℃ without significantly increasing electrode power. This increased melting zone temperature significantly reduces the viscosity of molten quartz, promoting the rapid merging, floating, and escape of internal microbubbles. Simultaneously, the high temperature eliminates microbubbles, resulting in a low-microbubble, high-quality quartz crucible. This method overcomes the temperature bottleneck of existing quartz crucible arc melting processes by combining high-temperature steam decomposition combustion technology with vacuum arc melting to construct a dual heat source system of "arc heating + hydrogen-oxygen combustion supplementary heating." This achieves both increased melting zone temperature and significant elimination of microbubbles. The heat released from hydrogen-oxygen combustion supplements arc heating, allowing for a reduction in graphite electrode power at the same melting temperature, thus reducing energy consumption and production costs.

[0183] The embodiments of the present invention have been described in detail above, but the content described is only a preferred embodiment of the present invention and should not be considered as limiting the scope of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the patent coverage of the present invention.

Claims

1. A method for preparing a quartz crucible, comprising preparing the quartz crucible using a vacuum arc melting method, characterized in that: At the first time point in the electric arc melting process, while maintaining the electric arc melting, a fluxing step is carried out. The fluxing step increases the melting temperature through the exothermic reaction of the flux.

2. The method for preparing a quartz crucible according to claim 1, characterized in that: The fluxing step includes: A reactive material is introduced into the melting zone, and the reactive material reacts upon heating to generate the flux. The temperature of the melting zone is monitored, and the flow rate of the reaction raw materials is controlled according to the temperature of the melting zone so that the temperature of the melting zone is controlled within the target temperature range.

3. The method for preparing a quartz crucible according to claim 2, characterized in that: The flow rate of the reaction raw materials is 0.5-2 L / min.

4. The method for preparing a quartz crucible according to claim 2 or 3, characterized in that: When controlling the flow rate of the reactants based on the temperature of the melting zone, the flow rate of the reactants is adjusted based on a comparison between the measured temperature of the melting zone and the target temperature range, including: If the temperature of the melting zone is within the target temperature range, the flow rate of the reactant is kept constant. If the temperature of the melting zone is greater than the maximum value of the target temperature, then reduce the flow rate of the reactants. If the temperature of the melting zone is less than the minimum value of the target temperature, then the flow rate of the reactant is increased.

5. The method for preparing a quartz crucible according to claim 4, characterized in that: The target temperature range is 2400℃-2600℃.

6. The method for preparing a quartz crucible according to claim 5, characterized in that: During the fluxing step, the power of the electrode used for arc melting is set to the melting power.

7. The method for preparing a quartz crucible according to claim 2, characterized in that: The reactants are vaporized before being introduced into the melting zone.

8. The method for preparing a quartz crucible according to claim 7, characterized in that: The reaction raw material is water vapor, and the flux is hydrogen and oxygen.

9. The method for preparing a quartz crucible according to any one of claims 1-3 and 5-8, characterized in that: The first time point is 3-6 minutes before the arc melting stops, and the melting process takes 1-3 minutes.

10. The method for preparing a quartz crucible according to claim 9, characterized in that: After the fluxing step is completed, a high-temperature holding process is performed, which includes: the power of the electrode used for arc melting is set to maintain a constant melting power for a first time, which is 1-3 minutes.

11. The method for preparing a quartz crucible according to claim 10, characterized in that: After the high-temperature holding process or the fluxing step is completed, an annealing cooling treatment is performed. The annealing cooling treatment includes: the power of the electrode used for arc melting is set to gradually decrease from the melting power to the minimum power within a second time period, which is 2-3 minutes.

12. A quartz crucible, characterized in that: It is prepared using the quartz crucible preparation method as described in any one of claims 1-11.

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