Reduction furnace and reduction method for preparing indium tin alloy by continuously reducing waste ITO target

Abstract

The invention discloses a reduction furnace and a reduction method for preparing an indium tin alloy by continuously reducing an ITO waste target. The reduction furnace comprises a furnace body, a reduction cavity is formed in the furnace body, a heating device is arranged between the inner wall of the furnace body and the reduction cavity, a discharging opening is formed in the bottom of the reduction cavity, a feeding opening is formed in the upper portion of the reduction cavity, and a charging bell is arranged at the feeding opening. The charging bell comprises a small bell and a large bell, and the small bell and the large bell are installed on a telescopic rotating mechanism. Through cooperation of the small clock and the large clock, safe and sustainable adding of the reduction mixture is achieved. Then the small clock and the large clock are controlled to move up and down and rotate through the telescopic rotating mechanism, so that the mixture can be uniformly distributed on the large clock hopper in the small clock hopper, the reduction efficiency can be effectively improved, and the problems that an existing reduction furnace cannot realize continuous reduction and segregation is caused by non-uniform reduction are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of reduction furnaces, and more specifically, to a reduction furnace and a reduction method for continuously reducing ITO waste targets to prepare indium tin alloy. Background Art

[0002] ITO (indium tin oxide), as a transparent conductive material, is widely used in modern electronic products such as liquid crystal displays and touch screens. With the popularization of these products, the generation amount of ITO waste targets has also increased. These waste targets contain valuable metal elements such as indium and tin. Therefore, recycling these waste targets not only helps with the recycling of resources but also reduces environmental pollution.

[0003] The carbothermal reduction technology is an effective method for recycling ITO waste targets. This technology uses carbon as a reducing agent to reduce indium oxide and tin oxide in ITO to metallic indium and tin under high-temperature conditions. Through the carbothermal reduction technology, not only can valuable metal resources be recovered, but also the potential harm of waste targets to the environment can be reduced, achieving the sustainable utilization of resources. With the increasing awareness of resource recycling and environmental protection, the application prospect of the carbothermal reduction technology in the field of ITO waste target recycling is broad. However, the recovery rate of indium by carbothermal reduction is low, and raw materials need to be repeatedly added, making it difficult to achieve continuous processing. Therefore, it is necessary to improve the recovery rate of carbothermal reduction of ITO waste targets and achieve continuous production to improve production efficiency. Recycling and reducing indium from waste materials have important economic and environmental significance.

[0004] In CN109762993A, a method for recovering metallic indium from ITO waste targets discloses that the ITO waste targets are pulverized by a ball mill and then mixed evenly with a reducing agent, graphite powder, and a graphite surface wetting agent to prepare particulate materials. The particulate materials are subjected to an oxidation-reduction reaction at high temperature to generate indium tin alloy. The oxidation-reduction reaction is carried out in a reduction furnace. The reduction furnace includes a furnace tube and a furnace partition fixedly arranged in the furnace tube and dividing the furnace tube into a reaction zone and an alloy storage zone. The upper end of the furnace tube is provided with a feeding port for facilitating feeding. The furnace partition is evenly provided with furnace partition holes through which alloy melt can pass but particulate materials cannot pass. A heating device is arranged outside the furnace tube at the lower part of the reaction zone, and a discharge nozzle in the shape of a tea spout is arranged on the side wall at the bottom end of the furnace tube. In this patent, the reduced indium tin alloy flows down through the furnace partition holes, and the unreduced particulate materials are above the furnace partition. And only by continuously adding particulate materials at the upper part can continuous operation be achieved. However, this device adopts the method of direct manual feeding, which has a low safety factor under high-temperature reduction conditions, and needs to be reduced batch by batch, making it difficult to carry out continuous reduction operations, with high energy consumption. At the same time, there is also the problem of uneven reduction caused by segregation of the reducing agent and ITO powder. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a reduction furnace for continuously reducing ITO waste targets to prepare indium tin alloy, aiming at the deficiencies of existing reduction furnaces that are difficult to operate continuously and there are segregation problems between the reducing agent and ITO powder, resulting in uneven reduction.

[0006] The present invention also provides a reduction method based on the reduction furnace for continuously reducing ITO waste targets to prepare indium tin alloy.

[0007] The object of the present invention is achieved by the following technical solutions:

[0008] A reduction furnace for continuously reducing ITO waste targets to prepare indium tin alloy, comprising a furnace body. A reduction chamber is provided inside the furnace body. A heating device is provided between the inner wall of the furnace body and the reduction chamber. An outlet is provided at the bottom of the reduction chamber, and an inlet is provided at the upper part of the reduction chamber. A charging bell is provided at the inlet.

[0009] The charging bell includes a small bell and a large bell. Hoppers are provided on both the small bell and the large bell. The hopper of the large bell is connected to the furnace body. The hopper of the small bell is connected to the hopper of the large bell. A rotating mechanism is provided on the outer wall of the hopper of the small bell, and the rotating mechanism is connected to a driving mechanism. The small bell and the large bell are installed on a telescopic connecting rod, and the connecting rod is connected to a power transmission mechanism.

[0010] Furthermore, a vacuum device is also provided on the furnace body and is connected to the reduction chamber.

[0011] Furthermore, the vacuum device includes a vacuum pump and a suction pipeline connecting the vacuum pump and the reduction chamber.

[0012] Furthermore, the outlet includes an iron notch and a slag notch. The molten metal after heating and reduction flows out from the iron notch, while the lighter non-metallic impurities in the mixture are discharged from the slag notch.

[0013] Furthermore, a filtering device is provided at the iron notch to prevent the mixture and the reduced molten metal from flowing out through the outlet simultaneously.

[0014] Furthermore, the filtering device is a filter screen, and the filter screen is made of a high-temperature resistant alloy.

[0015] Furthermore, the heating device includes a coil surrounding the reduction chamber and a temperature control system connected to the coil.

[0016] Furthermore, a sealing device is provided between the hopper of the small bell and the hopper of the large bell.

[0017] Furthermore, the rotating mechanism includes a gear set that meshes with each other. The driving mechanism controls the rotation of the small hopper by driving the gear set to rotate.

[0018] Furthermore, a pipeline is provided on the wall of the hopper of the large bell, and a pressure equalizing valve and a relief valve are provided on the pipeline.

[0019] A reduction method for continuously reducing ITO waste targets to prepare indium tin alloy, based on the reduction furnace for continuously reducing ITO waste targets to prepare indium tin alloy, the reduction steps include:

[0020] S1. Mix the ITO waste target powder with a reducing agent to obtain a reduction mixture; add the reduction mixture to the small bell hopper, and control the rotation of the small bell hopper through a driving mechanism so that the mixture rotates and mixes evenly in the small bell hopper;

[0021] S2. Control the telescopic movement of the connecting rod through a power transmission mechanism to control the descent of the small bell, open the small bell hopper, and the mixture falls from the small bell hopper into the large bell hopper. When the mixture in the large bell hopper accumulates, close the small bell hopper, and open the large bell hopper to make the mixture fall into the reduction furnace cavity;

[0022] S3. The reduction furnace is heated by a heating device, and the molten metal after heating and reduction flows out from the tapping hole, and the reaction residue flows out from the slag hole.

[0023] Further, the reducing agent includes one or more of graphite, coke, and activated carbon. Preferably, the reducing agent is activated carbon. Compared with graphite, coke, etc., activated carbon has more pores, a larger specific surface area, and a greater surface activity.

[0024] Further, the content of the reducing agent in the reduction mixture is 8-16 wt.%.

[0025] Further, the particle size of the ITO waste target powder is 200-300 mesh.

[0026] Further, the temperature of the heating reduction is 1000-1300 °C, and the time is 1.5-10 h.

[0027] Compared with the prior art, the beneficial effects are:

[0028] In the present invention, through the cooperation of the small bell and the large bell, the reduction mixture can be continuously and safely added. Then, through the telescopic rotation mechanism, the up and down movement and rotation of the small bell and the large bell are controlled, so that the mixture in the small bell hopper can be more evenly distributed on the large bell hopper to improve the reduction efficiency, and at the same time, the temperature stability in the reduction furnace can be ensured, preventing segregation from affecting the reduction effect. And through the control of the large bell and the small bell, the present invention can realize the continuous processing of ITO target reduction and improve the reduction efficiency of ITO waste target powder. Based on this reduction furnace, the present invention can realize continuous reduction, effectively avoid multiple furnace openings for heating and cooling, prevent heat loss, improve the reduction rate and thermal utilization rate, reduce the reduction temperature. The present invention further controls the dosage of ITO waste target powder and the reducing agent, reduces the production cost and energy consumption by reducing at 1000-1300 °C. Description of the Drawings

[0029] Figure 1 Schematic diagram of the reduction furnace structure for continuously reducing ITO waste targets to prepare indium tin alloy;

[0030] Figure 2 Structural diagram of the large bell and small bell;

[0031] Among them, 1 furnace body, 2 coil, 3 temperature control system, 4 taphole, 5 slag hole, 6 suction pipeline, 7 vacuum pump, 8 small bell, 9 large bell, 10 small bell hopper, 11 large bell hopper, 12 flange, 13 large gear, 14 small gear, 15 drive mechanism, 16 equalizing valve, 17 relief valve, 18 connecting rod.

[0032] Figure 3 Flow chart of the reduction for continuously reducing ITO waste targets to prepare indium tin alloy;

[0033] Figure 4 Reduction rate detection chart of the reducing agent dosage;

[0034] Figure 5 Reduction rate detection chart of the ITO waste target powder particle size;

[0035] Figure 6 Reduction rate detection chart of the reduction temperature and time. Detailed implementation manners

[0036] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0037] It should be noted that if there are directional indications (such as up, down, left, right, front, back) involved in the embodiments of the present invention, then the directional indications are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the drawings). If the specific posture changes, the directional indications will also change accordingly. If there are descriptions such as "first", "second", etc. involved in the embodiments of the present invention, then the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features.

[0038] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, terms such as "installation", "provided with", "connection", etc. shall be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0039] In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement them. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0040] Embodiment 1

[0041] This embodiment provides a reduction furnace for continuously reducing ITO waste targets to prepare indium tin alloy. A reduction chamber is provided inside the furnace body 1, and a heating device is provided between the inner wall of the furnace body 1 and the reduction chamber. The heating device includes an induction coil 2 surrounding the reduction chamber and a temperature control system 3 connected to the coil 2. The temperature of the induction coil 2 is regulated through the temperature control system 3 to achieve the adjustment of the reduction temperature and control the reduction speed. A discharge port is provided at the bottom of the reduction chamber. The discharge port includes a taphole 4 and a slag notch 5. The molten metal after heating and reduction flows out from the taphole 4. A filter screen is provided at the taphole 4 to prevent the mixture and the reduced molten metal from flowing out through the discharge port at the same time, while the lighter non-metallic impurities in the mixture are discharged from the slag notch 5. A vacuum suction port is provided in the reduction chamber. The vacuum suction port is connected to a vacuum pump 7 through a suction pipeline 6. A feed port is provided at the upper part of the reduction chamber, and a bell is provided at the feed port.

[0042] The bell includes a small bell 8 and a large bell 9. Hoppers are provided on both the small bell 8 and the large bell 9. The large bell hopper 11 is connected to the furnace body 1. The small bell hopper 10 is connected to the large bell hopper 11. A rotating mechanism is provided on the outer wall of the small bell hopper 10, and the rotating mechanism is connected to a driving mechanism 15. The small bell 8 and the large bell 9 are installed on a telescopic connecting rod 18, and the connecting rod 18 is connected to a power transmission mechanism.

[0043] Embodiment 2

[0044] This embodiment provides a reduction furnace for continuously reducing ITO waste targets to prepare indium tin alloy, as Figure 1, a reduction chamber is provided inside the furnace body 1, and a heating device is provided between the inner wall of the furnace body 1 and the reduction chamber. The heating device includes an induction coil 2 surrounding the reduction chamber and a temperature control system 3 connected to the coil 2. The temperature of the induction coil 2 is regulated by the temperature control system 3 to achieve the adjustment of the reduction temperature and control the reduction speed. A discharge port is provided at the bottom of the reduction chamber. The discharge port includes an iron notch 4 and a slag notch 5. The molten metal after heating and reduction flows out from the iron notch 4. A filter screen is provided at the iron notch 4 to prevent the mixture and the reduced molten metal from flowing out through the discharge port simultaneously, while the lighter non-metallic impurities in the mixture are discharged from the slag notch 5. A vacuum suction port is provided in the reduction chamber. The vacuum suction port is connected to a vacuum pump 7 through a suction pipeline 6. A feed port is provided at the upper part of the reduction chamber, and a bell is provided at the feed port.

[0045] As Figure 2 , the bell includes a small bell 8 and a large bell 9. Hoppers are provided on both the small bell 8 and the large bell 9. The large bell hopper 11 is connected to the furnace body 1 through a flange 12. The small bell hopper 10 is connected to the large bell hopper 11, and a sealing ring is provided between them for sealing. A large gear 13 is provided on the outer wall of the small bell hopper 10. At the same time, a small gear 14 is provided and meshes with the large gear 13. A driving mechanism 15 is connected to the small gear 14. The driving mechanism 15 drives the small gear 14 to rotate, thereby driving the small bell hopper 10 to rotate. The small bell 8 and the large bell 9 are installed on a coaxial telescopic connecting rod 18. The connecting rod 18 is connected to a power transmission mechanism. The power transmission mechanism controls the telescopic movement of the connecting rod 18 to drive the telescopic movement of the large bell hopper 11 and the small bell hopper 10.

[0046] Example 3

[0047] This embodiment provides a reduction furnace for continuously reducing ITO waste targets to prepare indium tin alloy. As Figure 1 , a reduction chamber is provided inside the furnace body 1, and a heating device is provided between the inner wall of the furnace body 1 and the reduction chamber. The heating device includes an induction coil 2 surrounding the reduction chamber and a temperature control system 3 connected to the coil 2. The temperature of the induction coil 2 is regulated by the temperature control system 3 to achieve the adjustment of the reduction temperature and control the reduction speed. A discharge port is provided at the bottom of the reduction chamber. The discharge port includes an iron notch 4 and a slag notch 5. The molten metal after heating and reduction flows out from the iron notch 4. A filter screen is provided at the iron notch 4 to prevent the mixture and the reduced molten metal from flowing out through the discharge port simultaneously, while the lighter non-metallic impurities in the mixture are discharged from the slag notch 5. A vacuum suction port is provided in the reduction chamber. The vacuum suction port is connected to a vacuum pump 7 through a suction pipeline 6. A feed port is provided at the upper part of the reduction chamber, and a bell is provided at the feed port.

[0048] As Figure 2, the bell includes a small bell 8 and a large bell 9. Hoppers are provided on both the small bell 8 and the large bell 9. The large bell hopper 11 is connected to the furnace body 1 through a flange 12. The small bell hopper 10 is connected to the large bell hopper 11, and a sealing ring is provided between them for sealing. A large gear 13 is provided on the outer wall of the small bell hopper 10. At the same time, a small gear 14 is provided and meshes with the large gear 13. The driving mechanism 15 is connected to the small gear 14. The driving mechanism 15 drives the small gear 14 to rotate, thereby driving the small bell hopper 10 to rotate. A pipeline is provided on the wall of the large bell hopper 11, and a pressure equalizing valve 16 and a relief valve 17 are provided on the pipeline. The small bell 8 and the large bell 9 are installed on a coaxial telescopic connecting rod 18. The connecting rod 18 is connected to the power transmission mechanism. The power transmission mechanism controls the telescoping of the connecting rod 18 to drive the telescoping of the large bell hopper 11 and the small bell hopper 10.

[0049] Example 4

[0050] This embodiment provides a reduction method for continuously reducing ITO waste targets to prepare indium tin alloys, as Figure 3 , and the steps include:

[0051] S1. Mix the ITO waste target powder with carbon powder to obtain a reduction mixture; add the reduction mixture to the small bell hopper, and control the rotation of the small bell hopper through the driving mechanism to make the mixture rotate and mix evenly in the small bell hopper;

[0052] S2. Control the telescoping of the connecting rod through the power transmission mechanism, control the small bell to descend, open the small bell hopper, and let the mixture fall from the small bell hopper into the large bell hopper. When the mixture in the large bell hopper reaches 2 / 3 of the large bell hopper, close the small bell hopper, and open the large bell hopper to let the mixture fall into the reduction furnace cavity;

[0053] S3. The reduction furnace is heated through a heating device, and the molten metal after heating and reduction flows out from the tapping hole, and the reaction residue flows out from the slag hole.

[0054] Example 5

[0055] In this embodiment, the reduction temperature is set to 1300 °C and the time is 3 h. The contents of the reducing agent in the reduction mixture are respectively set to 8 wt.%, 10 wt.%, 13 wt.%, and 16 wt.%, and the reduction rate is detected. The detection results are as Figure 4 shown. When the dosage of the reducing agent is 8 wt.%, the reduction rate is only 88.5%. When the dosage of the reducing agent reaches 10 wt.%, the reduction effect reaches the best, which is 96.5%. As the dosage of the reducing agent increases to 13 wt.%, the reduction rate is 95.6%, and there is some residual carbon powder in the porcelain boat. When the dosage of the reducing agent is increased to 16 wt.%, the reduction rate is almost the same as that at 13 wt.%, and there is a large amount of unreacted residual carbon powder in the porcelain boat.

[0056] Example 6

[0057] In this example, ITO waste target powders with particle sizes of 100 mesh - 200 mesh, 200 mesh - 300 mesh, and >300 mesh were selected respectively. At a reduction temperature of 1250 °C, they were kept warm for 2 h and 2.5 h respectively, and the reduction rate was detected. The detection results are as follows Figure 5 shown. When the holding time is set at 2 h, as the particle size increases from 100 - 200 mesh to 200 - 300 mesh, the reduction rate increases from 86% to 96.2%. However, as the particle size further increases to >300 mesh, the reduction rate remains almost unchanged. When the holding time is set at 2.5 h, the reduction rate hardly changes with the increase in particle size. This is because at 1200 °C, 2.5 h of reduction is sufficient for a full reaction, and the influence of particle size is small.

[0058] Example 7

[0059] In this example, target powder with a particle size of 200 - 300 mesh was used as the raw material, and 10 wt.% of carbon powder was used as the reducing agent. The reduction temperatures were set at 1100 °C, 1150 °C, 1200 °C, 1250 °C, and 1300 °C respectively, and the times were set at 1.5 h, 2 h, 2.5 h, 3 h, 3.5 h, 4 h, 4.5 h, 5 h, 6 h, and 7 h respectively, and the reduction rate was detected. The detection results are as follows Figure 6 shown. As the temperature increases, the holding time required to reach the maximum reduction rate becomes shorter and shorter. When the holding temperature is 1300 °C, the maximum reduction rate of 96% is reached after holding for 2 h. As the holding temperature drops to 1250 °C, the time required to reach the maximum reduction rate extends to 2.5 h. When the holding temperature is 1200 °C, the required holding time is 3 h. Almost every time the holding temperature drops by 50 °C, the holding time extends by 0.5 h. However, as the holding temperature further drops to 1150 °C, the required holding time extends to 4 h. When the holding temperature further drops to 1100 °C, the time required to reach the maximum reduction rate rises to 6 h. As the holding temperature decreases, the required holding time doubles.

[0060] In addition, the maximum reduction rate obtained at 1100 °C is less than that at other temperatures. However, as the temperature drops, the maximum reduction rate will increase because the evaporation rate of In slows down. Therefore, it is speculated that at 1100 °C, the amount of CO participating in the reaction decreases, resulting in difficulty for 10 wt.% of carbon powder to completely reduce the ITO target powder. And 11 wt.% of activated carbon powder is required to completely reduce the raw material. At 1050 °C, the reduction time is 8 h, and the amount of activated carbon powder required is 11.5 wt.%. When the temperature drops to 1000 °C, the reduction time is 10 h to complete the reduction. This shows that as the holding temperature increases, the required reduction time becomes longer and longer, and the amount of activated carbon also needs to be gradually increased. This is mainly because as the temperature decreases, the utilization rate of CO as a reducing agent becomes worse and more escapes.

[0061] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, rather than limitations on the implementation manners of the present invention. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to enumerate all implementation manners here. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. A reduction furnace for continuously reducing ITO waste targets to prepare indium tin alloy, characterized in that: It comprises a furnace body, wherein a reduction chamber is arranged in the furnace body, a heating device is arranged between the inner wall of the furnace body and the reduction chamber, a discharge port is arranged at the bottom of the reduction chamber, a feed port is arranged at the upper part of the reduction chamber, and a material bell is arranged at the feed port; The material bell includes a small bell and a large bell, both of which are provided with hoppers, the large bell hopper is connected to the furnace body, the small bell hopper is connected to the large bell hopper, the outer wall of the small bell hopper is provided with a rotating mechanism, the rotating mechanism is connected to the driving mechanism, the small bell and the large bell are installed on a retractable connecting rod, and the connecting rod is connected to the power transmission mechanism.

2. The reduction furnace for continuously reducing ITO waste targets to prepare indium tin alloy according to claim 1, characterized in that: The furnace body is also provided with a vacuum device connected to the reduction chamber, and the vacuum device comprises a vacuum pump and an air intake pipe connecting the vacuum pump and the reduction chamber.

3. The reduction furnace for continuously reducing ITO waste targets to prepare indium tin alloy according to claim 1, characterized in that: The discharge port includes an iron port and a slag port, and the iron port is provided with a filtering device.

4. The reduction furnace for continuously reducing ITO waste targets to prepare indium tin alloy according to claim 1, characterized in that: A sealing device is provided between the small bell hopper and the large bell hopper.

5. The reduction furnace for continuously reducing ITO waste targets to prepare indium tin alloy according to claim 1, characterized in that: The rotating mechanism includes a set of gears meshing with each other.

6. A method for continuously reducing ITO waste targets to prepare indium tin alloys, characterized in that: The reduction furnace for preparing indium tin alloy by continuous reduction of ITO waste targets according to any one of claims 1 to 9, wherein the reduction step comprises: S1. The ITO waste target powder is mixed with a reducing agent to obtain a reduced mixture; the reduced mixture is added to a small bell hopper, and the rotation of the small bell hopper is controlled by a driving mechanism so that the mixture is rotated and mixed in the small bell hopper; S2. The power transmission mechanism controls the extension and retraction of the connecting rod, controls the small bell to descend, opens the small bell hopper, and the mixture falls from the small bell hopper into the large bell hopper. When the mixture in the large bell hopper accumulates, the small bell hopper is closed, and the large bell hopper is opened to allow the mixture to fall into the reduction furnace chamber; S3. The reduction furnace is heated by a heating device, and the heated and reduced molten metal flows out from the iron outlet, and the reaction residue flows out from the slag outlet.

7. The reduction method for preparing indium tin alloy by continuously reducing ITO waste targets according to claim 6, characterized in that: The reducing agent includes one or more of graphite, coke, and activated carbon.

8. The reduction method for preparing indium tin alloy by continuously reducing ITO waste targets according to claim 6, characterized in that: The content of the reducing agent in the reducing mixture is 8-16 wt.%.

9. The reduction method for preparing indium tin alloy by continuously reducing ITO waste targets according to claim 6, characterized in that: The particle size of the ITO waste target powder is 200-300 meshes.

10. The reduction method for preparing indium tin alloy by continuously reducing ITO waste targets according to claim 6, characterized in that: The temperature of the heating reduction is 1000-1300° C., and the time is 1.5-10 hours.

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