A method for recovering coating of a reduction furnace bell, an auxiliary device for recovery, and a circulating system of a dissolving solution for recovery

Abstract

The application discloses a kind of reduction furnace bell cover layer recovery method, recovery auxiliary device and recovery dissolving liquid circulation system, it is related to polysilicon production field, specifically includes the following steps: to the reduction furnace bell cover layer of dissolving solution that dissolves reduction furnace bell inner wall is sent, dissolving solution is dissolved to the coating of reduction furnace bell inner wall, coating metal salt solution, gas and H2O generated after dissolving are sent out reduction furnace bell cover;To the coating metal salt solution generated is pyrolyzed, and metal and gas are generated after coating metal salt solution pyrolysis.The dissolving solution of the application is dissolved to the coating of reduction furnace bell inner wall, finally generates coating metal salt solution, gas and H2O, and to the coating metal salt solution generated is pyrolyzed, so that metal and gas are obtained, i.e.recovery to coating material is realized, waste to metal material is avoided, and enterprise production cost is reduced.

Description

Technical Field

[0001] This invention relates to the field of polycrystalline silicon production, and more specifically, to a method for recovering the coating of a reduction furnace bell jar, an auxiliary device for recovery, and a recycling system for the solvent. Background Technology

[0002] Polycrystalline silicon is a fundamental material in the photovoltaic and microelectronics industries, and the modified Siemens process is currently the mainstream method for producing polycrystalline silicon. The modified Siemens process is characterized by the following: in a bell-type chemical vapor deposition (CVD) reactor (industry term: polycrystalline silicon reduction furnace), a fine silicon core, electrically heated to 950℃-1150℃, serves as the deposition carrier. Trichlorosilane is introduced into the polycrystalline silicon reduction furnace, where it undergoes a hydrogen reduction reaction with hydrogen gas on the surface of the heated silicon core. The reduced silicon is deposited on the surface of the silicon core. As the hydrogen reduction reaction proceeds, the diameter of the silicon core gradually increases until it reaches the specified size, and is finally extracted in the form of a polycrystalline silicon rod.

[0003] The main material of the polysilicon reduction furnace is stainless steel. To prevent creep failure of the stainless steel due to excessively high internal wall temperature during operation, low-temperature water is typically circulated in the jacket between the outer and inner walls of the polysilicon reduction furnace for cooling, keeping the internal wall temperature below 300℃. During operation, the silicon rod surface emits a large amount of near-infrared electromagnetic waves. Most of these near-infrared electromagnetic waves reaching the inner wall are absorbed by the low-reflectivity stainless steel inner wall and converted into internal heat energy, which is then conducted to the high-heat-capacity low-temperature cooling water. Statistics show that the heat removed by the jacket cooling water accounts for more than 60% of the total input energy of the polysilicon reduction furnace.

[0004] To reduce heat loss carried away by the water in the bell jar of the reduction furnace and the precipitation of stainless steel impurities on the inner wall of the polycrystalline silicon reduction furnace, a high near-infrared electromagnetic wave reflective coating is usually applied to the inner wall of the reduction furnace to achieve energy saving and anti-fouling purposes in the production process. Such coatings are made of gold, silver, copper, etc. This coating has a certain service life. When the service life is reached, the old coating needs to be removed and a new coating needs to be prepared. However, metals such as gold, silver, and copper are expensive.

[0005] Therefore, there is an urgent need to develop a method for recovering the coating of a reduction furnace bell jar, auxiliary devices for recovery, and a recycling system for the solution used for recovery. Summary of the Invention

[0006] The purpose of this invention is to provide an auxiliary device, a recycling system, and a recycling solution circulation system for recycling the coating of a reduction furnace bell jar, which can effectively realize the recycling of the coating material on the inner wall of the reduction furnace bell jar.

[0007] To achieve the objective of this invention, the technical solution adopted is as follows:

[0008] A method for recovering the coating of a reduction furnace bell jar specifically includes the following steps:

[0009] A dissolving solution for dissolving the coating on the inner wall of the reduction furnace bell is introduced into the bell jar. The dissolving solution dissolves the coating on the inner wall of the reduction furnace bell jar, and the resulting coating metal salt solution, gas and H2O are sent out of the reduction furnace bell jar.

[0010] The generated coating metal salt solution is evaporated and crystallized, and then pyrolyzed. The coating metal salt is pyrolyzed to produce metal and gas.

[0011] Furthermore, the gas generated by pyrolysis is recovered and dissolved in water to prepare a solution.

[0012] Furthermore, the pyrolysis temperature of the coating metal salt is 400℃~1200℃.

[0013] Furthermore, the bell jar of the reduction furnace can be placed according to the requirements of the recycling method, such as horizontal or vertical placement.

[0014] Furthermore, during the process of dissolving the coating on the inner wall of the reduction furnace bell jar, the bell jar rotates synchronously.

[0015] Furthermore, the solution is one or more of hydrochloric acid and nitric acid.

[0016] Furthermore, the concentration of the solution is 1 wt% to 70 wt%.

[0017] Furthermore, the volume of the dissolving liquid fed into the bell jar of the reduction furnace shall not exceed half the internal volume of the bell jar.

[0018] Furthermore, the volume of the dissolving liquid fed into the bell jar of the reduction furnace is 1 / 4 to 1 / 2 of the internal volume of the bell jar.

[0019] Furthermore, the dissolving solution heats the inside of the reduction furnace bell jar while dissolving the coating on the inner wall of the bell jar.

[0020] Furthermore, the heating temperature inside the bell jar of the reduction furnace is 30℃~200℃, and the nitrogen pressure inside the bell jar of the reduction furnace is maintained at 0.1MPa~1MPa.

[0021] An auxiliary device for recovering the coating of a bell jar in a reduction furnace includes a horizontal frame and a drive mechanism for rotating the horizontal frame. The horizontal frame includes a rotating base for fixing the bell jar flange and a lifting ring connector for fixing the bell jar lifting ring. Multiple support rods are supported between the rotating base and the lifting ring connector. The rotating base also has a through hole and a feed pipe.

[0022] Furthermore, a heater is provided on the feed pipe.

[0023] Furthermore, the drive mechanism includes an active drive structure and a driven drive structure, which are located at both ends of the horizontal frame, respectively.

[0024] Furthermore, the rotating base is circular, and the active drive structure includes a fixed component and a drive component. There are two drive components, both of which are rotatably supported on the fixed component. The rotating base is supported on the two drive components together, and the fixed component is also equipped with a drive motor with adjustable speed that can drive the drive components to rotate.

[0025] Furthermore, both the driving component and the rotating base are provided with meshing teeth, and the meshing teeth on the driving component mesh with the meshing teeth on the rotating base.

[0026] Furthermore, the support rod is a telescopic structure.

[0027] Furthermore, the lifting ring connector is annular, and the driven structure includes a movable member that can reciprocate along the length of the support rod. The movable member supports two rotatable driven wheels, and the lifting ring connector is supported on the two driven wheels.

[0028] Furthermore, the driven structure also includes a guide rail, and the moving component is a slider that slides back and forth on the guide rail.

[0029] Furthermore, the rotating base and the lifting ring connector are provided with multiple sets of mounting holes, which are arranged at intervals along the radial direction of the rotating base, and each set of mounting holes includes mounting holes arranged at intervals around the circumference of the center of the rotating base.

[0030] A solution circulation system for recovering the coating of a reduction furnace bell jar includes the auxiliary device as described in any of the above, and further includes a solution container connected to a feed pipe and a coating metal salt collector connected to a through hole.

[0031] Furthermore, the outlet end of the coated metal salt collector is also connected to a pyrolysis reactor, and the outlet end of the pyrolysis reactor is also connected to a gas collector for collecting the gas after pyrolysis.

[0032] Furthermore, the gas collector is also connected to a first delivery pipeline for delivering gas to the solution container.

[0033] Furthermore, a second conveying pipe for conveying the gas generated during the coating dissolution process is connected between the coating metal salt collector and the gas collector.

[0034] Furthermore, the solution container is also connected to a displacement gas container for displacing the gas inside it.

[0035] The beneficial effects of this invention are:

[0036] This invention involves supplying a dissolving solution into the bell jar of a reduction furnace. The dissolving solution dissolves the coating on the inner wall of the bell jar, ultimately generating a coating metal salt solution, gas, and H2O. The coating metal salt obtained after evaporating and crystallizing the generated coating metal salt solution is then pyrolyzed to obtain metal and gas. This process achieves the recovery of the coating material, avoids waste of metal materials, and reduces the production cost for enterprises.

[0037] In this invention, by setting up a gas collector and connecting the gas collector to a solution container, a new solution can be obtained after the gas dissolves in water, thus realizing the whole-process recycling and reuse of the solution.

[0038] In this invention, by providing an auxiliary device, the coated metal on the inner wall of the bell jar can not only be installed horizontally when it needs to be recycled, but also rotated after horizontal installation, so as to ensure the integrity of the bell jar. This eliminates the need for disassembly and assembly of the bell jar itself when recycling the coated metal, thus improving recycling efficiency. Attached Figure Description

[0039] The accompanying drawings illustrate exemplary embodiments of the invention and, together with the description thereof, serve to explain the principles of the invention. These drawings are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification.

[0040] Figure 1 This is a schematic diagram of the auxiliary device for recycling the coating of the reduction furnace bell jar provided in Embodiment 3 of the present invention;

[0041] Figure 2 yes Figure 1 Schematic diagram of the bell jar structure of the reduction furnace;

[0042] Figure 3 yes Figure 1 Schematic diagram of a horizontal frame;

[0043] Figure 4 This is a schematic diagram of the structure of the rotating base and the driving component working together;

[0044] Figure 5 This is a schematic diagram of the structure of the bell jar's lifting ring and the driven wheel in operation;

[0045] Figure 6 This is a schematic diagram of the structure of the solvent circulation system for recycling the coating of the reduction furnace bell jar provided in Embodiment 4 of the present invention.

[0046] The attached diagram shows the markings and corresponding component names:

[0047] 1. Reduction furnace bell jar, 2. Horizontal frame, 3. Drive mechanism, 4. Dissolved liquid container, 5. Coated metal salt collector, 6. Pyrolysis reactor, 7. Gas collector, 8. Replacement gas container;

[0048] 101. Bell flange; 102. Bell lifting ring;

[0049] 201. Rotating base; 202. Support rod; 203. Lifting ring connector; 204. Engaging teeth; 205. Through hole; 206. Feed pipe; 207. Heater; 208. Mounting hole.

[0050] 301. Fixing component; 302. Driving component; 303. Guide rail; 304. Moving component; 305. Driven wheel. Detailed Implementation

[0051] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be noted that, for ease of description, only the parts relevant to the present invention are shown in the accompanying drawings.

[0052] It should be noted that, unless otherwise specified, the embodiments and features described in this invention can be combined with each other. The invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0053] Example 1

[0054] The present invention provides a method for recovering the coating of a reduction furnace bell jar, which specifically includes the following steps:

[0055] The bell jar 1 of the reduction furnace is sealed, forming a closed space inside. A dissolving solution for the coating on the inner wall of the bell jar 1 is then introduced into the bell jar 1. While ensuring the dissolving solution can dissolve the coating on the inner wall of the bell jar 1, different materials can be selected for the dissolving solution depending on the material of the coating, since the inner wall coating may contain metals such as gold, silver, and copper. The dissolution principle is as follows:

[0056] Coating metal + solution → Coating metal salt solution + gas + H2O

[0057] That is, after the dissolving solution dissolves the coating on the inner wall of the bell jar 1 of the reduction furnace, a coating metal salt solution, gas and H2O are obtained. It should be noted that the coating metal salt solution here refers to a salt solution containing coating metal ions. For example, if the coating on the inner wall of the bell jar 1 of the reduction furnace has a high near-infrared electromagnetic wave reflective coating such as gold, silver, or copper, then the formed coating metal salt solution is a salt solution containing gold ions, a salt solution containing silver ions, a salt solution containing copper ions, etc.

[0058] The resulting coating metal salt solution, gas, and H2O are discharged from the bell jar 1 of the reduction furnace. The obtained coating metal salt solution is then evaporated and crystallized before undergoing a pyrolysis reaction. The principle of the pyrolysis reaction is as follows:

[0059] Coating with metal salt → Metal + Gas

[0060] That is, after the coating metal salt is pyrolyzed, metal and gas are obtained. The metal here is the coating metal material, which realizes the recycling of coating materials, avoids the waste of metal materials, and reduces the production cost of enterprises.

[0061] As a further improvement of this embodiment, after the coating metal salt is pyrolyzed, the obtained gas is collected and dissolved in water. After the gas and water are dissolved, a new solution is obtained. This solution can be collected and used to dissolve the coating on the inner wall of the bell jar 1 of the reduction furnace, thus realizing the recycling and closed-loop utilization of the solution and greatly reducing the recycling cost of the coating metal.

[0062] As a further improvement to this embodiment, the pyrolysis temperature of the coated metal salt is 400℃~1200℃, which makes the pyrolysis efficiency of the coated metal salt higher, and the optimal pyrolysis temperature of the coated metal salt can be selected according to the actual situation.

[0063] As a further improvement in this embodiment, the reduction furnace bell jar 1 is placed horizontally, so that the dissolving liquid can dissolve the coating on the inner wall of the entire height of the reduction furnace bell jar 1 at one time, which increases the contact area between the dissolving liquid and the coating. This not only facilitates the dissolution of the coating, but also greatly reduces the amount of dissolving liquid used, thereby greatly improving the dissolution efficiency of the coating.

[0064] As a further improvement to this embodiment, in order to ensure that all the coatings on the inner wall of the reduction furnace bell jar 1 can be dissolved with a small amount of solution during the process of dissolving the coatings, the reduction furnace bell jar 1 can be rotated. The rotation speed of the reduction furnace bell jar 1 is between 1 r / h and 1 r / s. When the reduction furnace bell jar 1 is rotating, the solution fed into the reduction furnace bell jar 1 dissolves all the coatings on the inner wall of the reduction furnace bell jar 1 along with the rotation of the reduction furnace bell jar 1, so that all the coatings on the inner wall of the reduction furnace bell jar 1 can be recovered.

[0065] As a further improvement to this embodiment, the dissolving solution is one or more of hydrochloric acid and nitric acid. When the dissolving solution is both hydrochloric acid and nitrate, the hydrochloric acid and nitrate can be mixed in a certain proportion. In actual operation, the specific type of dissolving solution used can be selected according to the type of coating material, so as to ensure the dissolution efficiency of the coating without damaging its essence.

[0066] As a further improvement to this embodiment, the concentration of the solution is 1wt% to 70wt%. The specific selection of the solution concentration can be determined according to the type of coating material, the thickness of the coating, etc. The concentration of the solution can be arbitrarily selected while ensuring the dissolution efficiency.

[0067] As a further improvement to this embodiment, in order to facilitate the discharge of the dissolving solution from the reduction furnace bell jar 1 after dissolving the coating, the reduction furnace bell jar 1 must have a through hole 205 for discharging the coating metal salt solution. In order to prevent the dissolving solution from leaking from the through hole 205 during the dissolution of the coating, the volume of the dissolving solution fed into the reduction furnace bell jar 1 is not greater than half of the internal volume of the reduction furnace bell jar 1, so that the coating area dissolved by the dissolving solution at one time is not greater than half of the inner wall of the reduction furnace bell jar 1. While avoiding leakage of the dissolving solution from the reduction furnace bell jar 1, the coating area dissolved by the dissolving solution at one time is maximized. In this invention, without considering the amount of dissolving solution used or leakage, the reduction furnace bell jar 1 can be placed vertically, and the reduction furnace bell jar 1 does not need to be rotated. The volume of the dissolving solution can also be greater than half of the internal volume of the reduction furnace bell jar 1, or even the volume of the dissolving solution can be directly the internal volume of the reduction furnace bell jar 1. At the same time, when the reduction furnace bell jar 1 is placed vertically, in order to reduce the amount of dissolving solution used, the dissolving solution can also be sprayed onto the inner wall of the reduction furnace bell jar 1, so that the dissolving solution can contact the metal coating on the inner wall of the reduction furnace bell jar 1 and achieve dissolution.

[0068] As a further improvement of this embodiment, the volume of the dissolving liquid fed into the bell jar 1 of the reduction furnace is 1 / 4 to 1 / 2 of the internal volume of the bell jar 1 of the reduction furnace. This ensures the dissolving efficiency while preventing the dissolving liquid from leaking out of the bell jar 1 of the reduction furnace. The volume of the dissolving liquid can be selected arbitrarily.

[0069] As a further improvement to this embodiment, during the process of dissolving the coating on the inner wall of the reduction furnace bell jar 1, the solution heats the inside of the reduction furnace bell jar 1 to increase the temperature of the solution, thereby greatly improving the dissolution efficiency of the solution.

[0070] As a further improvement to this embodiment, the heating temperature inside the reduction furnace bell jar 1 is 30℃~200℃. The heating temperature inside the reduction furnace bell jar 1 can be selected arbitrarily without damaging the dissolution quality of the solution. At the same time, to prevent other gases from entering the reduction furnace bell jar 1 during the dissolution of the coating and affecting the dissolution, nitrogen gas is also filled into the reduction furnace bell jar 1 for pressure maintenance, so that the pressure inside the reduction furnace bell jar 1 is maintained at 0.1MPa~1MPa.

[0071] Example 2

[0072] The inner wall coating of the reduction furnace bell jar is silver. The specific steps for recycling the reduction furnace bell jar coating are as follows:

[0073] The bell jar 1 of the reduction furnace is sealed, forming a closed space inside. HNO3, a dissolving agent for the silver coating on the inner wall of the bell jar 1, is then introduced into the bell jar 1. The dissolution principle of HNO3 on the silver coating on the inner wall of the bell jar 1 is as follows:

[0074] Ag + HNO3 → AgNO3 + NO x +H2O

[0075] That is, after the dissolving solution dissolves the coating on the inner wall of the bell jar 1 of the reduction furnace, AgNO3 solution and gaseous NO are obtained. x and H2O.

[0076] The AgNO3 solution and NO gas generated after dissolution x H2O is discharged from the bell jar 1 of the reduction furnace, and the resulting AgNO3 solution is evaporated and crystallized before undergoing a pyrolysis reaction. The principle of the pyrolysis reaction is as follows:

[0077] 2AgNO3→2Ag+2NO2+O2

[0078] That is, AgNO3 is pyrolyzed to obtain Ag and NO2 gas, which realizes the recycling of coating materials, avoids the waste of silver materials, and reduces the production cost of enterprises.

[0079] As a further improvement to this embodiment, after the pyrolysis of AgNO3, the resulting gas NO2 and the gas NO obtained from dissolving Ag are treated separately. X The collected NO gas was collected and then... X When dissolved in water, its reaction is as follows:

[0080] NO X +O2 +H2O → HNO3

[0081] NO X After being dissolved in water, a new solution of HNO3 is obtained. This HNO3 solution can be collected and used to dissolve the silver coating on the inner wall of the bell jar 1 of the reduction furnace, thus realizing the recovery and closed-loop utilization of the HNO3 solution and greatly reducing the recovery cost of the silver coating.

[0082] As a further improvement to this embodiment, the pyrolysis temperature of AgNO3 is 400℃~1200℃, which makes the pyrolysis efficiency of AgNO3 higher, and the optimal pyrolysis temperature of AgNO3 can be selected according to the actual situation.

[0083] As a further improvement in this embodiment, the reduction furnace bell jar 1 is placed horizontally, so that the dissolving solution HNO3 can dissolve the silver coating of the entire height of the reduction furnace bell jar 1 at one time, and the contact area between the dissolving solution HNO3 and the silver coating is larger. This not only facilitates the dissolution of silver, but also greatly reduces the amount of dissolving solution HNO3 used, thereby greatly improving the dissolution efficiency of the silver coating.

[0084] As a further improvement to this embodiment, in order to ensure that all the silver coating on the inner wall of the reduction furnace bell jar 1 can be dissolved with a small amount of HNO3 during the process of dissolving the silver coating on the inner wall of the reduction furnace bell jar 1, the reduction furnace bell jar 1 can be rotated. The rotation speed of the reduction furnace bell jar 1 is between 1 r / h and 1 r / s. When the reduction furnace bell jar 1 is rotating, the HNO3 solution fed into the reduction furnace bell jar 1 dissolves all the silver coating on the inner wall of the reduction furnace bell jar 1 along with the rotation of the reduction furnace bell jar 1, so that all the silver coating on the inner wall of the reduction furnace bell jar 1 can be recovered.

[0085] As a further improvement to this embodiment, the concentration of HNO3 in the dissolving solution is 1wt% to 70wt%. The specific selection of the concentration of HNO3 in the dissolving solution can be determined according to the thickness of the silver coating, etc. While ensuring dissolution efficiency, the concentration of HNO3 in the dissolving solution can be selected arbitrarily.

[0086] As a further improvement to this embodiment, in order to facilitate the discharge of the dissolving solution HNO3 from the reduction furnace bell jar 1 after dissolving the silver coating, the reduction furnace bell jar 1 must have a through hole 205 for discharging the AgNO3 solution. In order to prevent the dissolving solution HNO3 from leaking from the through hole 205 during the dissolution of the silver coating, the volume of the dissolving solution fed into the reduction furnace bell jar 1 is no more than half of the internal volume of the reduction furnace bell jar 1, so that the area of ​​the silver coating dissolved by the dissolving solution in one go is no more than half of the inner wall of the reduction furnace bell jar 1. While avoiding the leakage of the dissolving solution HNO3 from the reduction furnace bell jar 1, the area of ​​the coating dissolved by the dissolving solution HNO3 in one go is maximized. In this invention, without considering the amount of HNO3 used in the dissolving solution and HNO3 leakage, the reduction furnace bell jar 1 can be placed vertically, and the reduction furnace bell jar 1 does not need to be rotated. The volume of the dissolving solution can also be greater than half of the internal volume of the reduction furnace bell jar 1, or even the volume of the dissolving solution can be directly the internal volume of the reduction furnace bell jar 1. At the same time, when the reduction furnace bell jar 1 is placed vertically, in order to reduce the amount of dissolving solution used, the dissolving solution can also be sprayed onto the inner wall of the reduction furnace bell jar 1, so that the dissolving solution can come into contact with the metal coating on the inner wall of the reduction furnace bell jar 1 and dissolve it.

[0087] As a further improvement of this embodiment, the volume of the HNO3 solution fed into the bell jar 1 of the reduction furnace is 1 / 4 to 1 / 2 of the internal volume of the bell jar 1 of the reduction furnace. This ensures the dissolution efficiency while preventing the HNO3 solution from leaking out of the bell jar 1 of the reduction furnace. The volume of the HNO3 solution can be selected arbitrarily.

[0088] As a further improvement to this embodiment, during the process of dissolving the coating on the inner wall of the reduction furnace bell jar 1, the solution heats the inside of the reduction furnace bell jar 1 to increase the temperature of the solution, thereby greatly improving the dissolution efficiency of the solution.

[0089] As a further improvement to this embodiment, the heating temperature inside the bell jar 1 of the reduction furnace is 30℃~200℃. The heating temperature inside the bell jar 1 of the reduction furnace can be selected arbitrarily without damaging the dissolution quality of the HNO3 solution. At the same time, to prevent other gases from entering the bell jar 1 of the reduction furnace during the dissolution of the silver coating by the HNO3 solution and affecting the dissolution, nitrogen gas is also filled into the bell jar 1 of the reduction furnace for pressure maintenance, so that the pressure inside the bell jar 1 of the reduction furnace is maintained at 0.1MPa~1MPa.

[0090] Example 3

[0091] In this embodiment, to implement the recycling method in Example 1, Example 3 also provides an auxiliary device for recycling the coating of a reduction furnace bell jar. This auxiliary device is used to fix and install the reduction furnace bell jar 1. Specifically, the auxiliary device includes a horizontal frame 2 and a drive mechanism 3. The horizontal frame 2 is a frame placed horizontally, with its axis extending horizontally. The drive mechanism 3 can drive the horizontal frame 2 to rotate. The horizontal frame 2 includes a rotating base 201 and a lifting ring connector 203. There is a certain distance between the rotating base 201 and the lifting ring connector. Since the lower end of the reduction furnace bell jar 1 has a bell jar flange 101 and the upper end of the reduction furnace bell jar 1 has a bell jar lifting ring 102, and... The bell flange 101 is annular, and there are multiple bell lifting rings 102. The multiple bell lifting rings 102 are evenly spaced along the circumference of the outer wall of the reduction furnace bell 1. The rotating base 201 on the horizontal frame 2 is used to fix the bell flange 101, and the lifting ring connector 203 is used to fix the bell lifting rings 102. In order to ensure the connection between the lifting ring connector 203 and the rotating base 201, a support rod 202 is also provided between the rotating base 201 and the lifting ring connector 203. At the same time, in order to maintain the stability between the rotating base 201 and the lifting ring connector 203, there are at least two support rods 202. The multiple support rods 202 are evenly spaced along the central circumference of the lifting ring connector 203.

[0092] In actual use, the bell flange 101 at the lower end of the reduction furnace bell jar 1 is fixed to the rotating base 201. At this time, the rotating base 201 seals the lower end of the reduction furnace bell jar 1, forming a sealed chamber inside the reduction furnace bell jar 1. In order to send the solution into or out of the reduction furnace bell jar 1, the rotating base 201 is also provided with a through hole 205 for sending the solution out of the reduction furnace bell jar 1. In order to prevent the solution from overflowing from the through hole 205 when the solution in the reduction furnace bell jar 1 is less than half full, the through hole 205 can be preferably set in the center of the rotating base 201 so that the highest liquid level of the solution in the reduction furnace bell jar 1 can reach the difference between the inner radius of the reduction furnace bell jar 1 and the radius of the through hole 205. At the same time, the rotating base 201 is also provided with a feed pipe 206 extending into the reduction furnace bell jar 1, so that the solution can be added into the reduction furnace bell jar 1 through the feed pipe 206.

[0093] In this invention, to prevent the feed pipe 206 from being thrown during the rotation of the reduction furnace bell jar 1 due to its eccentric installation on the rotating base 201, the diameter of the through hole 205 can be enlarged. The feed pipe 206 is installed inside the through hole 205. Furthermore, to prevent the feed pipe 206 from blocking the through hole 205, the outer diameter of the feed pipe 206 is smaller than the diameter of the through hole 205, creating a gap between the outer wall of the feed pipe 206 and the wall of the through hole 205. This gap allows the dissolved liquid inside the reduction furnace bell jar 1 to drain out. In this invention, since the feed pipe 206 cannot block the through hole 205 while being installed inside it, multiple reinforcing rods pointing towards the center of the through hole 205 can be fixed inside the through hole 205 during installation. The feed pipe 206 is then fixed together on these reinforcing rods, thus achieving a fixed installation of the feed pipe 206.

[0094] When it is necessary to recycle the coating on the inner wall of the reduction furnace bell jar 1, the horizontal frame 2 can be placed vertically first, and the reduction furnace bell jar 1 can be vertically lifted using hoisting equipment. During the hoisting process, the bell jar flange 101 at the lower end of the reduction furnace bell jar 1 passes through the lifting ring connector 203, so that the reduction furnace bell jar 1 is placed on the rotating base 201, and the bell jar lifting ring 102 is supported on the lifting ring connector 203. At the same time as the reduction furnace bell jar 1 is placed on the rotating base 201, the feed pipe 206 extends into the reduction furnace bell jar 1. Finally, the bell jar flange 101 is fixed to the rotating base 201 with screws, and the bell jar lifting ring 102 is fixed to the lifting ring connector 203 with screws, so that the reduction furnace bell jar 1 is fixed on the horizontal frame 2.

[0095] The horizontal frame 2 with the reduction furnace bell jar 1 installed is hoisted so that the horizontal frame 2 with the reduction furnace bell jar 1 installed is placed horizontally and driven by the drive mechanism 3. This not only realizes the horizontal installation of the reduction furnace bell jar 1, but also realizes the drive of the reduction furnace bell jar 1, so that the reduction furnace bell jar 1 can rotate in the horizontal state, thereby meeting the requirements for the recycling of the inner wall coating of the reduction furnace bell jar 1.

[0096] As a further improvement to this embodiment, a heater 207 is provided on the feed pipe 206. The heater 207 can be an electric heater. The heater 207 can not only heat the solution fed through the feed pipe 206, but also heat the internal environment of the reduction furnace bell jar 1, so that the solution has a higher dissolution efficiency when dissolving the coating material.

[0097] As a further improvement to this embodiment, the drive mechanism 3 includes an active drive structure and a driven drive structure. The active drive structure actively drives the horizontal frame 2, and the driven drive structure is driven by the active drive structure to drive the horizontal frame 2. The active drive structure and the driven drive structure are located at opposite ends of the horizontal frame 2, so that one end of the horizontal frame 2 is driven by the active drive structure, and the other end of the horizontal frame 2 rotates passively with the drive of the active drive structure, making the rotation of the horizontal frame 2 more stable. It should be noted that in this embodiment, there can also be multiple driven drive structures. In this case, multiple driven drive structures and the active drive structure are evenly spaced along the axial direction of the horizontal frame 2, which not only provides sufficient support for the horizontal frame 2, but also ensures that the horizontal frame 2 rotates more smoothly.

[0098] As a further improvement to this embodiment, the rotating base 201 is circular, and the through hole 205 is located at the center of the rotating base 201. After the reduction furnace bell jar 1 is installed, the maximum liquid level of the dissolving liquid that can be injected into the reduction furnace bell jar 1 is the inner wall radius of the reduction furnace bell jar 1 minus the radius of the through hole 205. This allows the maximum amount of dissolving liquid to be injected into the reduction furnace bell jar 1, thereby increasing the range of options for the amount of dissolving liquid injected into the reduction furnace bell jar 1 and allowing the use of the minimum amount of dissolving liquid while ensuring dissolution efficiency. The active drive structure includes a fixing component 301 and a driving component 302. The fixing frame can be directly fixed on the ground or a base. The axis of the driving component 302 extends horizontally, and there are two driving components 302 with a certain distance between them. When the horizontal frame 2 is placed in a horizontal position, the outer circular surface of the rotating base 201 is supported by the two driving components 302. Through the cooperation between the driving component 302 and the outer circular surface of the rotating base 201, the rotation of the rotating base 201 and the driving component 302 is not affected while supporting the rotating base 201.

[0099] To drive the rotating base 201 to rotate, a drive motor (not shown in the figure) for driving the drive component 302 to rotate is also installed on the fixing component 301. There is only one drive motor, and the drive motor can drive any one of the drive components 302 to rotate. At the same time, the output end of the drive motor can be directly connected to the axle of the drive component 302 through a coupling. In order to reduce the speed of the drive component 302, a speed reducer can also be set, so that the output end of the drive motor is connected to the input end of the speed reducer, and the output end of the speed reducer is connected to the axle of the drive component 302. Of course, if a speed reducer is not set, the drive motor can also be a variable frequency motor, and the speed of the drive motor can be adjusted by adjusting the frequency of the drive motor, thereby adjusting the speed of the drive component 302.

[0100] As a further improvement to this embodiment, both the driving component 302 and the rotating base 201 are provided with meshing teeth 204, that is, the driving component 302 is a small gear and the rotating base 201 is a large gear, and the meshing teeth 204 on the driving component 302 and the meshing teeth 204 on the rotating base 201 mesh with each other, effectively preventing slippage between the driving component 302 and the rotating base 201, making the mutual rotation between the driving component 302 and the rotating base 201 more stable, avoiding vibration of the reduction furnace bell jar 1 installed on the horizontal frame 2 during the coating recovery process, and ensuring the dissolution of the coating by the solvent.

[0101] As a further improvement to this embodiment, the support rod 202 is a telescopic structure. The support rod 202 can be directly made of hydraulic rods, cylinders or electronic telescopic components and other automatic telescopic elements. By telescoping the support rod 202, the distance between the rotating base 201 and the lifting ring connector 203 can be adjusted, thereby meeting the installation requirements of the reduction furnace bell jar 1 of different heights and making the auxiliary device more widely applicable.

[0102] As a further improvement to this embodiment, the lifting ring connector 203 is annular, and the inner diameter of the lifting ring connector 203 is larger than the diameter of the bell flange 101 on the bell jar 1 of the reduction furnace, ensuring that the bell flange 101 of the reduction furnace bell jar 1 can pass through the lifting ring connector 203 and abut against the rotating base 201 when the bell jar 1 is installed on the horizontal frame 2; at the same time, since the inner diameter of the lifting ring connector 203 is larger than the diameter of the bell flange 101, the length of the bell jar lifting ring 102 on the bell jar 1 of the reduction furnace needs to be greater than the width of the bell flange 101. Preferably, the extended end of the bell jar lifting ring 102 is flush with the outer circular surface of the lifting ring connector 203. The driven structure includes a movable component 304 that can reciprocate along the length of the support rod 202. The moving direction of the movable component 304 is consistent with the extension and retraction direction of the support rod 202. When the reduction furnace bell jar 1 is installed, the moving direction and moving distance of the movable component 304 are the same as the extension and retraction direction and extension and retraction distance of the support rod 202. The movable component 304 also supports two driven wheels 305. With the center of the lifting ring connector 203 as the center, the two driven wheels 305 are located on the ring formed with the center, so that the wheel surface of the two driven wheels 305 is engaged with the outer circular surface of the lifting ring connector 203. When the horizontal frame 2 is placed in a horizontal position, the outer circular surface of the lifting ring connector 203 is supported by the two driven wheels 305. Through the engagement between the outer circular surface of the driven wheels 305 and the outer circular surface of the lifting ring connector 203, the rotation of the driven wheels 305 and the lifting ring connector 203 is not affected while supporting the lifting ring connector 203.

[0103] The drive motor drives the drive component 302 to rotate, and the outer surface of the drive component 302 engages with the rotating base 201, so that the drive component 302 drives the rotating base 201 to rotate at the same time. Since the lifting ring connector 203 is connected to the rotating base 201 through the support rod 202, and the lifting ring connector 203 cooperates with the driven wheel 305, the lifting ring connector 203 and the drive component 302 rotate relative to each other while the rotating base 201 rotates, so that the horizontal frame 2 and the reduction furnace bell jar 1 installed on the horizontal frame 2 rotate synchronously, so that the dissolving liquid injected into the reduction furnace bell jar 1 dissolves the coating.

[0104] As a further improvement to this embodiment, the driven structure further includes a guide rail 303. The length direction of the guide rail 303 is consistent with the axial direction of the support rod 202, and the guide rail 303 has a groove. The cross-section of the groove is rectangular or U-shaped. The moving part 304 is a slider that can reciprocate within the groove. The cross-section of the moving part 304 is T-shaped. The moving part 304 can reciprocate along the groove. In order to prevent the moving part 304 from continuing to slide after sliding to the fixed position of the groove, a screw can also be provided on the moving part 304. When the moving part 304 slides to the fixed position, the screw is tightened so that the screw abuts against the guide rail 303. When the moving part 304 needs to slide, the screw can be loosened. In this embodiment, the cross-section of the guide rail 303 can also be "I" shaped. In this case, a T-slot can be opened on the lower surface of the moving part 304, and the moving part 304 can be slidably locked on the guide rail 303 through the T-slot. At the same time, in order to prevent the moving part 304 from falling off the guide rail 303, blocks that restrict the moving part 304 can also be provided at both ends of the guide rail 303.

[0105] As a further improvement to this embodiment, the rotating base 201 and the lifting ring connector 203 are also provided with multiple sets of mounting holes. These sets of mounting holes on the rotating base 201 are spaced apart along the radial direction of the rotating base 201. Each set of mounting holes on the rotating base 201 includes mounting holes 208 spaced apart circumferentially around the center circumference of the rotating base 201. Similarly, the multiple sets of mounting holes on the lifting ring connector 203 are spaced apart along the radial direction of the lifting ring connector 203. Each set of mounting holes on the lifting ring connector 203 includes mounting holes 208 spaced apart circumferentially around the center circumference of the lifting ring connector 203. Through the cooperation of the mounting holes 208 on the rotating base 201 and the lifting ring connector 203, reduction furnace bell jars 1 of different sizes can be installed on the horizontal frame 2.

[0106] To prevent the large-sized reduction furnace bell jar 1 from being installed on the auxiliary device, where the diameter of the bell jar flange 101 on the bell jar 1 is larger than the diameter of the circle formed by the mounting hole group near the center of the rotating base 201, causing the dissolving liquid fed into the reduction furnace bell jar 1 to flow directly out through the mounting hole group near the center of the rotating base 201 after the reduction furnace bell jar 1 is installed on the auxiliary device, wooden or rubber plugs can be used to block the remaining mounting holes 208 on the rotating base 201. Alternatively, all mounting holes 208 on the rotating base 201 can be blocked with wooden or rubber plugs before the reduction furnace bell jar 1 is installed on the auxiliary device. When the reduction furnace bell jar 1 needs to be installed, the wooden or rubber plugs in the mounting holes 208 corresponding to the bolt holes on the bell jar flange 101 can be removed. Therefore, by opening multiple mounting hole groups on the rotating base 201 and arranging the multiple mounting hole groups at intervals along the radial direction of the rotating base, the dissolution of the metal coating on the inner wall of the reducing furnace bell jar 1 by the dissolving liquid is not affected while satisfying the installation of bell jars 1 of different sizes.

[0107] Before the coating on the inner wall of the reduction furnace bell jar 1 needs to be recycled, the reduction furnace bell jar 1 can be rotated while in a horizontal position. In this case, the reduction furnace bell jar 1 can be installed with an auxiliary device to rotate the reduction furnace bell jar 1 in a horizontal position, as follows:

[0108] The horizontal frame 2 is hoisted using hoisting tools, detaching it from the drive mechanism 3 and placing it vertically. Then, the telescopic rod retracts, causing the lifting ring connector 203 to move closer to the rotating base 201. The reduction furnace bell jar 1 is then lifted using hoisting tools. During the lifting process, the lower end of the bell jar 1 passes through the lifting ring connector 203 and is placed downwards onto the rotating base 201, ensuring that the central axis of the reduction furnace bell jar 1 is aligned with the center of the rotating base 201. While the reduction furnace bell jar 1 is placed on the rotating base 201, the feed pipe 206 installed in the through hole 205 extends into the inside of the reduction furnace bell jar 1. Then, the bell jar flange 101 is fixed to the rotating base 201 with screws. The telescopic rod extends, and the telescopic rod drives the lifting ring connector 203 to approach the bell jar lifting ring 102. When the lifting ring connector 203 and the bell jar lifting ring 102 come into contact, the telescopic rod stops extending. The bell jar lifting ring 102 and the lifting ring connector 203 are fixed with screws, so that the reduction furnace bell jar 1 is fixed on the horizontal frame 2.

[0109] Loosen the moving part 304 and manually push it to slide along the track. When the distance between the driven wheel 305 on the moving part 304 and the driving part 302 on the fixed part 301 is equal to the distance between the rotating base 201 and the lifting ring connector 203, fix the moving part 304 to the guide rail 303. Lay the horizontal frame 2 with the reduction furnace bell jar 1 installed on it horizontally using a lifting tool, and lift the horizontal frame 2 with the lifting tool. During the lifting process, place the rotating base 201 on the two driving parts 302 and place the lifting ring connector 203 on the two driven wheels 305, so that the horizontal frame 2 with the reduction furnace bell jar 1 fixed on it is placed on the drive mechanism 3.

[0110] The dissolving solution is fed into the reduction furnace bell jar 1 through the feed pipe 206. After the dissolving solution for dissolving the coating is fed into the reduction furnace bell jar 1 through the feed pipe 206, the drive motor is started. The drive motor drives one of the drive components 302 to rotate. Through the engagement of the drive component 302 with the rotating base 201, the drive component 302 drives the rotating base 201 to rotate. Through the cooperation of the lifting ring connector 203 and the driven wheel 305, the horizontal frame 2 and the reduction furnace bell jar 1 mounted on the horizontal frame 2 rotate synchronously, so that the reduction furnace bell jar 1 rotates in a horizontal state. Through the rotation of the reduction furnace bell jar 1, the dissolving solution comes into contact with the coating, and the dissolving solution dissolves the coating, realizing the recovery of the coating. During the process of dissolving solution transportation and dissolving coating, the heater 207 heats the dissolving solution and the internal environment of the reduction furnace bell jar 1.

[0111] When the solution dissolves the coating and needs to be discharged from the reduction furnace bell jar 1, the hoisting tool lifts the horizontal frame 2 and places it in a vertical position. At this time, the coating metal salt solution generated in the reduction furnace bell jar 1 can be discharged through the gap between the wall of the through hole 205 and the feed pipe 206, and the heater 207 stops heating.

[0112] In this embodiment, to simplify the operation, a tilting frame can be set up, and the fixing component 301 and the track are installed on the tilting frame. In order to prevent the rotating base 201 from disengaging from the driving component 302 and the lifting ring connector 203 from the driven wheel 305 during the tilting process of the horizontal frame 2, a binding structure for easy binding and unbinding of the horizontal frame 2 can be fixed on the tilting frame. The binding structure can bind the horizontal frame 2 to the tilting frame during the tilting process, so that when the reduction furnace bell jar 1 needs to be installed on the horizontal frame 2, or when the reduction furnace bell jar 1 needs to be removed from the horizontal frame 2, or when the coating metal salt solution in the reduction furnace bell jar 1 needs to be discharged, the tilting frame can tilt the horizontal frame 2 to make it stand upright. Thus, during the installation or removal of the reduction furnace bell jar 1, it is not necessary to lift the horizontal frame 2 from the driving mechanism 3, making the installation and removal of the reduction furnace bell jar 1 more convenient.

[0113] Example 4

[0114] Based on the recycling method in Example 1 and the auxiliary device in Example 2, in order to recycle the dissolving liquid fed into the reduction furnace bell jar 1, this Example 3 also provides a dissolving liquid recycling system for the reduction furnace bell jar coating. In addition to the auxiliary device as described in Example 2, it also includes a dissolving liquid container 4 and a coating metal salt collector 5. The dissolving liquid container 4 is used to store the dissolving liquid for dissolving the coating, and the coating metal salt collector 5 is used to collect the coating metal salt solution formed after the coating is dissolved. Specifically, the outlet end of the dissolving liquid container 4 is connected to the inlet end of the feed pipe 206. Since the reduction furnace bell jar 1 needs to be rotated after being installed on the horizontal frame 2, in order to avoid the pipe connecting the feed pipe 206 and the dissolving liquid container 4 from getting tangled during the rotation of the reduction furnace bell jar 1 by the horizontal frame 2, the outlet end of the pipe is connected to the inlet end of the feed pipe 206 through a rotary joint. Similarly, in order to avoid the pipe connecting the through hole 205 and the coating metal salt collector 5 from getting tangled during the rotation of the reduction furnace bell jar 1 by the horizontal frame 2, the inlet end of the pipe is also connected to the through hole 205 through a rotary joint.

[0115] When the reduction furnace bell jar 1 is installed on the horizontal frame 2 and the coating needs to be dissolved, the dissolving liquid in the dissolving liquid container 4 is fed into the reduction furnace bell jar 1 through the feed pipe 206. When the amount of dissolving liquid fed into the reduction furnace bell jar 1 reaches the required level, the feeding of dissolving liquid into the reduction furnace bell jar 1 is stopped. The drive motor is started, and the drive motor drives one of the drive components 302 to rotate. The drive component 302 meshes with the rotating base 201, so that the drive component 302 drives the rotating base 201 to rotate when it rotates. Through the cooperation of the lifting ring connector 203 and the driven wheel 305, the horizontal frame 2 and the reduction furnace bell jar 1 installed on the horizontal frame 2 rotate synchronously, so that the reduction furnace bell jar 1 rotates in a horizontal state. Through the rotation of the reduction furnace bell jar 1, the dissolving liquid comes into contact with the coating and dissolves the coating.

[0116] When the dissolving solution and coating completely dissolve to form a coating metal salt solution, the hoisting tool lifts the horizontal frame 2 to a vertical position. At this time, the coating metal salt solution generated in the reduction furnace bell jar 1 can be discharged through the gap between the wall of the through hole 205 and the feed pipe 206 and sent into the coating metal salt collector 5, thus completing the recovery of the coating.

[0117] As a further improvement to this embodiment, the outlet end of the coated metal salt collector 5 is also connected to a pyrolysis reactor 6. The pyrolysis reactor 6 is used to evaporate and crystallize the collected coated metal salt solution, and then perform a pyrolysis reaction after crystallization to reduce it to metal and gas. The outlet end of the pyrolysis reactor 6 is also connected to a gas collector 7, which is used to collect the gas generated during the pyrolysis reaction. By collecting the gas and metal separately, the gas can be recycled and reused, and the metal can be used to continue preparing the coating on the inner wall of the polycrystalline silicon reduction furnace bell jar 1, thus realizing the recycling and closed-loop utilization of the coating.

[0118] As a further improvement to this embodiment, the gas collector 7 is also connected to a first delivery pipeline that delivers the gas generated by pyrolysis to the solution container 4, so that the gas obtained later can be dissolved in the solution and used for coating recovery, thereby realizing the recovery and closed-loop utilization of the solution.

[0119] As a further improvement to this embodiment, since gas is generated in addition to coating metal salt solution during the reaction between coating and solvent, a second conveying pipe (not shown in the figure) is connected between coating metal salt collector 5 and gas collector 7. The second conveying pipe can directly transport the gas generated during coating dissolution from coating metal salt collector 5 to gas collector 7.

[0120] As a further improvement to this embodiment, since the solution and the coating metal need to maintain pressure inside the reduction furnace bell jar 1 during the reaction process, a displacement gas container 8 is also connected to the solution container 4. The displacement gas container 8 is filled with nitrogen gas for maintaining pressure inside the reduction furnace bell jar 1. By connecting it in parallel to the outlet end of the solution container 4, the nitrogen gas in the displacement gas container 8 is sent into the reduction furnace bell jar 1 through the feed pipe 206. The gas generated by the solution and the coating metal in the reduction furnace bell jar 1 during the reaction process is sent into the metal salt collector 5 and the gas collector 7 through the through hole 205 in sequence, and finally displaced into the gas collector 7.

[0121] When this system is used in conjunction with auxiliary devices, its specific working principle is as follows:

[0122] When it is necessary to recycle the coating on the inner wall of the reduction furnace bell jar 1, the reduction furnace bell jar 1 should be installed first. The installation method of the reduction furnace bell jar 1 is as follows:

[0123] The horizontal frame 2 is hoisted using hoisting tools, detaching it from the drive mechanism 3 and placing it vertically. Then, the telescopic rod retracts, causing the lifting ring connector 203 to move closer to the rotating base 201. The reduction furnace bell jar 1 is then lifted using hoisting tools. During the lifting process, the lower end of the bell jar 1 passes through the lifting ring connector 203 and is placed downwards onto the rotating base 201, ensuring that the central axis of the reduction furnace bell jar 1 is aligned with the center of the rotating base 201. While the reduction furnace bell jar 1 is placed on the rotating base 201, the feed pipe 206 installed in the through hole 205 extends into the inside of the reduction furnace bell jar 1. Then, the bell jar flange 101 is fixed to the rotating base 201 with screws. The telescopic rod extends, and the telescopic rod drives the lifting ring connector 203 to approach the bell jar lifting ring 102. When the lifting ring connector 203 and the bell jar lifting ring 102 come into contact, the telescopic rod stops extending. The bell jar lifting ring 102 and the lifting ring connector 203 are fixed with screws, so that the reduction furnace bell jar 1 is fixed on the horizontal frame 2.

[0124] Loosen the moving part 304 and manually push it to slide along the track. When the distance between the driven wheel 305 on the moving part 304 and the driving part 302 on the fixed part 301 is equal to the distance between the rotating base 201 and the lifting ring connector 203, fix the moving part 304 to the guide rail 303. Lay the horizontal frame 2 with the reduction furnace bell jar 1 installed on it horizontally using a lifting tool, and lift the horizontal frame 2 with the lifting tool. During the lifting process, place the rotating base 201 on the two driving parts 302 and place the lifting ring connector 203 on the two driven wheels 305, so that the horizontal frame 2 with the reduction furnace bell jar 1 fixed on it is placed on the drive mechanism 3.

[0125] Next, the coating on the inner wall of the original furnace bell jar was dissolved and recycled. The dissolution and recycling methods are as follows:

[0126] The outlet end of the solution container 4 is connected to the inlet end of the feed pipe 206 via a rotary joint and a pipe, and the through hole 205 is connected to the inlet end of the coating metal salt collector 5 via a rotary joint and a pipe. The solution in the solution container 4 is fed into the reduction furnace bell jar 1 through the feed pipe 206. When the amount of solution fed into the reduction furnace bell jar 1 reaches the required level, the feeding of solution into the reduction furnace bell jar 1 is stopped. The drive motor is started, and the drive motor drives one of the drive components 302 to rotate. Through the engagement of the drive component 302 with the rotating base 201, the drive component 302 drives the rotating base 201 to rotate. Through the cooperation of the lifting ring connector 203 and the driven wheel 305, the horizontal frame 2 and the reduction furnace bell jar 1 mounted on the horizontal frame 2 rotate synchronously, so that the reduction furnace bell jar 1 rotates in a horizontal state. Through the rotation of the reduction furnace bell jar 1, the solution comes into contact with the coating, and the solution dissolves the coating.

[0127] Next, the replacement gas container 8 is opened, and the nitrogen gas in the replacement gas container 8 is sent into the bell jar 1 of the reduction furnace through the feed pipe 206. This causes the gas generated by the solution during the dissolution of the coating metal to be discharged through the through hole 205 and enter the coating metal salt collector 5. The gas entering the coating metal salt collector 5 is sent into the gas collector 7 through the second conveying pipe, so that the gas generated by the solution during the dissolution of the coating metal is replaced by the gas collector 7.

[0128] When the solution and coating completely dissolve to form a coating metal salt solution, the hoisting tool lifts the horizontal frame 2, making it vertical. At this time, the coating metal salt solution and gas generated in the reduction furnace bell jar 1 can be discharged through the gap between the wall of the through hole 205 and the feed pipe 206 and sent into the coating metal salt collector 5. The gas entering the coating metal salt collector 5 is directly sent into the gas collector 7 through the conveying pipe, while the coating metal salt solution entering the coating metal salt collector 5 is sent into the pyrolysis reactor 6 for pyrolysis. The coating metal salt solution is pyrolyzed to generate metal and gas. The generated metal is directly sent out of the pyrolysis reactor 6, and the generated gas is sent into the gas collector 7. The gas collected in the gas collector 7 is sent into the solution container 4. The solution in the solution container 4 absorbs the gas to obtain a new solution for the next coating recovery.

[0129] In the description of this specification, the references to terms such as "one embodiment / mode," "some embodiments / modes," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment / mode or example is included in at least one embodiment / mode or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment / mode or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments / modes or examples. Furthermore, without contradiction, those skilled in the art can combine and integrate the different embodiments / modes or examples described in this specification, as well as the features of different embodiments / modes or examples.

[0130] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0131] Those skilled in the art should understand that the above embodiments are merely for illustrating the present invention and are not intended to limit the scope of the invention. Those skilled in the art can make other changes or modifications based on the above disclosure, and these changes or modifications still fall within the scope of the present invention.

Claims

1. A solvent circulation system for recovering the coating of a reduction furnace bell jar, characterized in that, The invention includes an auxiliary device for recovering the coating of a bell jar in a reduction furnace. The auxiliary device for recovering the coating of a bell jar in a reduction furnace includes a horizontal frame (2) and a drive mechanism (3) for rotating the horizontal frame (2). The horizontal frame (2) includes a rotating base (201) for fixing the bell jar flange (101) and a lifting ring connector (203) for fixing the bell jar lifting ring (102). Multiple support rods (202) are supported between the rotating base (201) and the lifting ring connector (203). A through hole (205) is also provided on the rotating base (201), and a feed pipe (206) is also provided on the rotating base (201). It also includes a solution container (4) connected to the feed pipe (206) and a coating metal salt collector (5) connected to the through hole (205); the outlet end of the coating metal salt collector (5) is also connected to a pyrolysis reactor (6), and the outlet end of the pyrolysis reactor (6) is also connected to a gas collector (7) for collecting the gas generated by pyrolysis; the gas collector (7) is also connected to a first conveying pipeline for conveying the gas generated by pyrolysis to the solution container (4); the coating metal salt collector (5) and the gas collector (7) are also connected to a second conveying pipeline for conveying the gas generated during the coating dissolution process.

2. The solvent circulation system for recovering the coating of the reduction furnace bell jar according to claim 1, characterized in that, A heater (207) is provided on the feed pipe (206).

3. The solvent circulation system for recovering the coating of the reduction furnace bell jar according to claim 1, characterized in that, The drive mechanism (3) includes an active drive structure and a driven drive structure, which are located at both ends of the horizontal frame (2).

4. The solvent circulation system for recovering the coating of the reduction furnace bell jar according to claim 3, characterized in that, The rotating base (201) is circular. The active drive structure includes a fixed part (301) and a drive part (302). There are two drive parts (302). Both drive parts (302) are rotatably supported on the fixed part (301). The rotating base (201) is supported on the two drive parts (302). A drive motor for driving any drive part (302) to rotate is also installed on the fixed part (301).

5. The solvent circulation system for recovering the coating of the reduction furnace bell jar according to claim 1, characterized in that, The support rod (202) is a telescopic structure.

6. The solvent circulation system for recovering the coating of the reduction furnace bell jar according to claim 5, characterized in that, The lifting ring connector (203) is ring-shaped. The driven structure includes a movable part (304) that can reciprocate along the length of the support rod (202). The movable part (304) is supported by two rotatable driven wheels (305). The lifting ring connector (203) is supported on the two driven wheels (305).

7. The solvent circulation system for recovering the coating of the reduction furnace bell jar according to claim 6, characterized in that, The driven structure further includes a guide rail (303) and a moving part (304) which is a slider that slides back and forth on the guide rail (303).

8. The solvent circulation system for recovering the coating of the reduction furnace bell jar according to claim 1, characterized in that, The rotating base (201) and the lifting ring connector (203) are also provided with multiple sets of mounting holes. The multiple sets of mounting holes are arranged at intervals along the radial direction of the rotating base (201), and each set of mounting holes includes mounting holes (208) arranged at intervals around the circumference of the center of the rotating base (201).

9. A method for recovering the coating of a reduction furnace bell jar based on a solution circulation system for recovering the coating of a reduction furnace bell jar as described in any one of claims 1 to 8, characterized in that, Specifically, the steps include the following: A dissolving solution for dissolving the coating on the inner wall of the bell jar (1) is delivered into the bell jar (1) of the reduction furnace. The dissolving solution dissolves the coating on the inner wall of the bell jar (1). The resulting coating metal salt solution, gas and H2O are sent out of the bell jar (1). The generated coating metal salt solution is evaporated and crystallized, and then pyrolyzed. The coating metal salt is pyrolyzed to produce metal and gas.

10. The method for recovering the coating of the reduction furnace bell jar according to claim 9, characterized in that, The gas generated by pyrolysis is recovered and dissolved in water to prepare a solution.

11. The method for recovering the coating of the bell jar in a reduction furnace according to claim 9, characterized in that, The pyrolysis temperature of the coating metal salt is 400℃~1200℃.

12. The method for recovering the coating of the reduction furnace bell jar according to claim 9, characterized in that, The bell jar (1) of the reduction furnace is placed horizontally.

13. The method for recovering the coating of the reduction furnace bell jar according to claim 12, characterized in that, During the process of dissolving the coating on the inner wall of the reduction furnace bell jar (1), the reduction furnace bell jar (1) rotates synchronously.

14. The method for recovering the coating of the reduction furnace bell jar according to claim 9, characterized in that, The solution is one or more of hydrochloric acid and nitric acid.

15. The method for recovering the coating of the reduction furnace bell jar according to claim 9 or 14, characterized in that, The concentration of the solution is 1 wt% to 70 wt%.

16. The method for recovering the coating of the reduction furnace bell jar according to claim 9, characterized in that, The volume of the dissolving liquid fed into the bell jar (1) of the reduction furnace shall not exceed half the internal volume of the bell jar (1).

17. The method for recovering the coating of the reduction furnace bell jar according to claim 16, characterized in that, The volume of the dissolving liquid fed into the bell jar (1) of the reduction furnace is 1 / 4 to 1 / 2 of the internal volume of the bell jar (1).

18. The method for recovering the coating of the reduction furnace bell jar according to claim 9, characterized in that, The solution heats the inside of the bell jar (1) of the reduction furnace during the process of dissolving the coating on the inner wall of the bell jar (1).

19. The method for recovering the coating of the reduction furnace bell jar according to claim 18, characterized in that, The heating temperature inside the bell jar (1) of the reduction furnace is 30℃~200℃, and the nitrogen pressure inside the bell jar (1) of the reduction furnace is 0.1MPa~1MPa.

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