A system for sulfiding tin by recycling SO2 as a sulfiding agent in a fumigation furnace.

Abstract

This utility model discloses a system for recycling SO2 as a sulfiding agent in a fuming furnace to volatilize tin, belonging to the field of tin smelting technology. In this system, an SO2 compressor, an SO2 storage tank, a fuming furnace, a bag filter, and an SO2 treatment device are sequentially connected; the SO2 treatment device consists of an SO2 absorption tower, an SO2 desorption tower, and an SO2 drying tower. Using this method, SO2, which was originally adsorbed, desorbed, and dried from smelting flue gas for acid production, is pressurized by a compressor and stored in a storage tank. Then, during fuming in the furnace, it is mixed with combustion air and injected into the furnace through the fuming furnace nozzle, replacing the conventional sulfiding agent—pyrite—to complete the tin volatilization process. The SO2 is then recovered after entering the flue gas desulfurization system, ultimately achieving recycling. This utility model can significantly reduce the operating cost of tin volatilization in a fuming furnace and greatly improve the economic efficiency of the furnace.

Description

Technical Field

[0001] This utility model relates to the field of tin smelting technology, specifically to a system for using SO2 as a sulfiding agent in a fumigation furnace to sulfide and volatilize tin. Background Technology

[0002] As the grade of tin ore in large tin mines decreases year by year, the amount of difficult-to-process ore gradually increases. In order to improve the tin beneficiation recovery rate, mines must reduce the beneficiation enrichment ratio, resulting in a decrease in tin concentrate grade and an increase in the output of tin middlings (containing 3-5% Sn). At the same time, due to the reduction in high-grade tin concentrate on the market, the grade of tin smelting furnace feed is showing a downward trend, which in turn leads to an increase in the amount of low-tin slag (containing 3-5% Sn). The volume of tin-containing materials that need to be processed in fuming furnaces is showing an upward trend year by year.

[0003] The sulfidation and volatilization process in tin fuming furnaces is the optimal route for processing tin ore and low-tin slag. The average grade of tin-containing dust produced after fuming and volatilization can reach over 50%. Tin fuming furnaces generally use pyrite as the sulfiding agent. After the low-tin material has completed its smelting process in the furnace, it is added back into the furnace, reacting to generate SnS which volatilizes into the flue gas and is oxidized to SnO2 in the rising flue of the furnace, then recovered during the dust collection process. In recent years, changes in the domestic sulfur market supply and demand have led to an increase in sulfur prices, and the price of pyrite, one of the raw materials for sulfur production, has also risen accordingly, increasing the production cost of fuming furnaces.

[0004] Pyrite has been the most commonly used sulfiding agent in tin fuming furnaces for decades, mainly due to its wide availability, ease of transportation and storage, and simple addition method—it can be added directly from the furnace feed during fuming. Furthermore, as a high-sulfur (S>30%) sulfiding agent, its price is relatively low. SO2, on the other hand, presents challenges in storage and transportation, is difficult to add during fuming, and is particularly expensive, limiting its application in the practical application of fuming tin volatilization. Therefore, there has never been any industrial application of SO2 as a sulfiding agent for tin volatilization. In recent years, with increasingly stringent environmental requirements and continuous advancements in flue gas treatment technology in tin smelters, SO2 in tin smelter flue gas can now be purified and recovered separately. As a byproduct of environmental protection facilities, it no longer needs to be purchased and transported from outside the factory, significantly reducing its usage cost and creating favorable conditions for the direct application of SO2 as a sulfiding agent in fuming furnaces.

[0005] Given the increasing volume of low-tin materials and the rising cost of sulfiding agents, developing a high-efficiency, low-cost sulfidation volatilization process is of great practical significance. Many large tin smelters are equipped with flue gas SO2 recovery processes. These processes address SO2-containing flue gas from fluidized bed roasting furnaces, fuming furnaces, rotary kilns, and top-blown smelting furnaces. High-concentration SO2 is obtained through adsorption-desorption using organic amine liquid and then used to produce sulfuric acid. If the plant uses the SO2 recovered from the tail gas system as a sulfiding agent, it can achieve the recycling and self-sufficiency of the sulfiding agent, greatly improving the production efficiency of the fuming furnace and reducing its production costs. Utility Model Content

[0006] This invention aims to at least partially solve one of the aforementioned technical problems in the prior art. This invention uses SO2 recovered from the tail gas treatment system of a tin smelter as a sulfiding agent, directly applied to the sulfidation of low-tin materials in a fuming furnace, forming a novel process for the recycling of the sulfiding agent in the fuming furnace. The system of this invention centrally controls the collection and supply of SO2 through a DCS control system, realizing the recycling of SO2 as a sulfiding agent in a tin fuming furnace.

[0007] Therefore, one objective of this utility model is to provide a system for sulfiding volatile tin by using SO2 as a sulfiding agent in a fuming furnace, including an SO2 compressor, an SO2 storage tank, a fuming furnace, a bag filter dust collector, and an SO2 treatment device.

[0008] The SO2 compressor, SO2 storage tank, fumigation furnace, bag filter dust collector, and SO2 treatment device are connected in sequence.

[0009] The SO2 treatment device consists of an SO2 absorption tower, an SO2 desorption tower, and an SO2 drying tower.

[0010] The SO2 absorption tower is connected to the bag filter dust collector, and the outlet of the SO2 drying tower is connected to the SO2 compressor.

[0011] The SO2 absorption tower, SO2 desorption tower, and SO2 drying tower are connected in sequence.

[0012] Furthermore, the fumigation furnace includes a gas mixing chamber and a molten pool;

[0013] The gas mixing chamber is connected to the SO2 storage tank, and the molten pool is connected to the bag filter dust collection device;

[0014] The gas mixing chamber is equipped with an SO2 pipe, a combustion air pipe, a mixing chamber, and a fuming furnace duct; the SO2 pipe and the combustion air pipe are located on one side of the mixing chamber; the fuming furnace duct is located on the other side of the mixing chamber and is symmetrical to the SO2 pipe.

[0015] The SO2 pipeline is connected to the SO2 storage tank, the combustion air pipeline is connected to the outside air, and the fuming furnace air duct is connected to the molten pool.

[0016] Furthermore, both the SO2 pipeline and the combustion air pipeline are equipped with check valves.

[0017] Furthermore, a first electrically operated shut-off ball valve is provided between the SO2 drying tower and the SO2 compressor;

[0018] A second electrically operated shut-off ball valve is provided between the SO2 compressor and the SO2 storage tank;

[0019] A flow-controlled electric shut-off valve and a flow meter are sequentially installed between the SO2 storage tank and the fuming furnace.

[0020] Furthermore, the system also includes a catalytic conversion acid production device;

[0021] The catalytic conversion acid production device is connected to the outlet of the SO2 drying tower, and a third electric shut-off ball valve is provided between the catalytic conversion acid production device and the SO2 drying tower.

[0022] In the system of this invention, SO2 is used as a direct sulfurizing agent to volatilize tin during the operation of the fuming furnace. The main chemical reactions that may occur are (1), (2), and (3) above. In addition, using SO2 as a sulfurizing agent may also cause reactions (4)-(9), which also contribute to the sulfurizing and volatilization of tin.

[0023] SO2 + Sn + 2CO = SnS + 2CO2 (1)

[0024] SO2 + SnO + 3CO = SnS + 3CO2 (2)

[0025] SO2 + SnO2 + 4CO = SnS + 4CO2 (3)

[0026] SO2 + C = S + CO2 (4)

[0027] SO2 + 2C = COS + CO (5)

[0028] SO2 + 3CO = COS + 2CO2 (6)

[0029] Sn + COS = SnS + CO (7)

[0030] SnO + COS = SnS + CO2 (8)

[0031] SnO2 + 2COS = SnS2 + 2CO2 (9)

[0032] Since the ΔG values ​​of reactions (1)-(3) are much less than zero at the tin fuming temperature (1150-1250℃), it indicates that these three chemical reactions have strong chemical reaction potentials; similarly, the ΔG values ​​of reactions (4)-(9) are also less than zero at the fuming temperature. Based on the above analysis, it is theoretically feasible to use SO2 as a sulfiding agent to sulfide and volatilize tin under a high-temperature, weakly reducing atmosphere. Moreover, from a kinetic perspective, since directly using SO2 as a sulfiding agent eliminates the step of pyrite decomposition and oxidation, its reaction rate is higher.

[0033] This utility model also provides a method for using SO2 as a sulfiding agent in the above-mentioned fumigation furnace to sulfide volatilized tin, including the following steps:

[0034] (1) Close the third electric shut-off ball valve, open the first electric shut-off ball valve and the second electric shut-off ball valve, and at the same time turn on the SO2 compressor. The SO2 obtained after adsorption-desorption-drying in the tin smelting tail gas acid production system is pressurized by the SO2 compressor and then stored in the SO2 storage tank.

[0035] (2) When the SO2 storage tank pressure is 0.5-0.6MPa, close the first electric shut-off ball valve, the SO2 compressor and the second electric shut-off ball valve, and open the third electric shut-off ball valve at the same time;

[0036] (3) Open the flow control electric shut-off valve. After SO2 gas and combustion air of the fuming furnace are mixed in the gas mixing chamber, it is injected into the molten pool of the fuming furnace through the fuming furnace air pipe. At this time, strictly control the air-coal ratio of the fuming furnace to ensure that the pulverized coal injected into the fuming furnace is in an incomplete combustion state and the furnace is in a weak reducing atmosphere.

[0037] (4) SnS generated by fuming and volatilization is oxidized by the air blown into the flue during the flue gas rise, generating SnO2 and SO2, which are separated in the bag dust collection device. SO2 enters the SO2 treatment device, is processed, and then compressed and returned to the SO2 storage tank to complete the recycling of SO2 as a sulfiding agent for sulfiding and volatilizing tin.

[0038] Furthermore, the SO2 compressor pressurization pressure in step (1) is 0.5-0.6 MPa.

[0039] Furthermore, in step (3), the SO2 gas flow rate is 1.1-1.2 times the theoretical sulfur required for tin volatilization in a single furnace, the flow rate is controlled based on the sulfidation time of 0.5-2.5h, and the total oxygen content of SO2 gas and the oxygen content of combustion air are controlled within the range of 0.7-0.9 to meet the excess air coefficient of pulverized coal combustion in the fuming furnace.

[0040] Furthermore, the method described above by this utility model also includes the following steps:

[0041] (5) When the fuming furnace completes the sulfurization and volatilization operation of one batch of material, the sulfur dioxide flow rate is set to zero, the flow control electric shut-off valve is automatically closed, and the supply of SO2 to the fuming furnace is stopped until the next batch enters the sulfurization and volatilization operation process, and then the SO2 supply is set to start again.

[0042] (6) When the SO2 storage tank pressure drops below 0.25 MPa due to the sulfurization operation in the fuming furnace, the control system automatically closes the third electric shut-off ball valve connecting to the sulfuric acid production process and opens the first electric shut-off ball valve connecting to the sulfur dioxide compressor. Subsequently, the SO2 compressor and the second electric shut-off ball valve are simultaneously opened to begin the sulfur dioxide storage tank filling operation. Thus, the fuming furnace achieves recycling of SO2 as a sulfurizing agent. Furthermore, due to minimal losses during the recycling process, when SO2 in the smelting flue dust is not compressed and recovered, the surplus SO2 gas produced by other production sections of the tin smelter is treated according to the original sulfuric acid production process, resulting in the normal production of sulfuric acid as a byproduct.

[0043] (7) Based on the above principle analysis, SO2, as a sulfurizing agent, carries oxygen atoms that eventually react with carbon elements in the pulverized coal fed into the fuming furnace to generate CO2. Therefore, in the actual sulfurization and volatilization operation, the mixing ratio of SO2 and combustion air can be adjusted arbitrarily as needed, so as to achieve arbitrary adjustment of sulfur potential in the fuming furnace without affecting the exothermic reaction of pulverized coal.

[0044] The beneficial effects of this utility model are as follows:

[0045] 1) For tin smelters capable of using flue gas SO2 to produce acid, the adoption of this utility model solution can enable the sulfurizing agent of the fuming furnace to be self-sufficient and recycled, eliminating the need to purchase additional sulfurizing agent, significantly reducing the production cost of the fuming furnace, and demonstrating good economic benefits.

[0046] 2) The system of this utility model can recover SO2 from the fluidized roasting process, smelting process and rotary kiln process of tin smelter. After SO2 is recovered through the tail gas system, it can be used to supplement the sulfur loss in the SO2 sulfidation and volatilization process of the fuming furnace, so that SO2 can be recycled and reused. There is no need to purchase and replenish SO2 separately.

[0047] 3) The fuming furnace uses SO2 as a sulfiding agent, which eliminates the decomposition and oxidation steps of pyrite compared to using pyrite, resulting in higher sulfidation efficiency. Furthermore, the method of directly injecting SO2 gas from the bottom tuyeres of the fuming furnace pool, compared to adding solid pyrite from the top feed inlet of the fuming furnace, allows for more thorough contact between the sulfiding agent and the melt, further improving sulfidation efficiency and shortening the time required for tin volatilization in a single furnace.

[0048] 4) Using SO2 as a sulfiding agent, compared with using solid pyrite as a sulfiding agent, will not occupy the furnace bed capacity of the fuming furnace, nor will it increase the amount of slag discharged. It can improve the processing capacity of the fuming furnace while reducing the amount of tin carried away by the slag in the fuming furnace, thereby further improving the economic benefits of the fuming furnace.

[0049] 5) Since the SO2 gas source has a stable composition, it is easier to add the sulfurizing agent to the fuming furnace in a quantitative manner in a gaseous state. This makes the operation of the fuming furnace more standardized and precise, and further improves the production efficiency of the fuming furnace.

[0050] 6) Since the SO2 supplied to the fuming furnace as a sulfiding agent carries oxygen atoms that eventually react with the carbon elements of the pulverized coal supplied to the fuming furnace to generate CO2, and the high concentration of SO2 also has a high oxygen content, when the fuming furnace is in the sulfidation stage, the addition of combustion air is reduced, the amount of flue gas is reduced, and the sulfur potential of sulfidation volatilization is further increased to accelerate the sulfidation volatilization rate and reduce heat loss. Attached Figure Description

[0051] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0052] Figure 1 This is a schematic diagram of the structure of the fuming furnace of this utility model, which uses SO2 as a sulfiding agent to sulfide and volatilize tin.

[0053] Figure 2 This is a schematic diagram of the gas mixing chamber structure of the fuming furnace in this utility model.

[0054] The structures represented by each number in the attached diagram are listed below: 1-SO2 compressor, 2-SO2 storage tank, 3-fumigation furnace, 4-bag filter dust collector, 5-SO2 absorption tower, 6-SO2 desorption tower, 7-SO2 drying tower, 8-first electric shut-off ball valve, 9-second electric shut-off ball valve, 10-flow control electric shut-off valve, 11-flow meter, 12-catalytic conversion acid production unit, 13-third electric shut-off ball valve, 31-SO2 pipeline, 32-combustion air pipeline, 33-mixing chamber, 34-fumigation furnace duct, 35-check valve. Detailed Implementation

[0055] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model.

[0056] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0057] 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 one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0058] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0059] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0060] Example 1

[0061] A system for sulfiding volatile tin by using SO2 as a sulfiding agent in a fuming furnace is characterized by comprising an SO2 compressor 1, an SO2 storage tank 2, a fuming furnace 3, a bag filter dust collector 4, and an SO2 treatment device.

[0062] The SO2 compressor 1, SO2 storage tank 2, fuming furnace 3, bag dust collection device 4, and SO2 treatment device are connected in sequence.

[0063] The SO2 treatment unit consists of an SO2 absorption tower 5, an SO2 desorption tower 6, and an SO2 drying tower 7.

[0064] SO2 absorption tower 5 is connected to bag dust collector 4, and the outlet of SO2 drying tower 7 is connected to SO2 compressor 1.

[0065] SO2 absorption tower 5, SO2 desorption tower 6 and SO2 drying tower 7 are connected in sequence.

[0066] In some embodiments, the fumigation furnace includes a gas mixing chamber and a molten pool;

[0067] The gas mixing chamber is connected to the SO2 storage tank 2, and the molten pool is connected to the bag dust collection device 4.

[0068] The gas mixing chamber is equipped with an SO2 pipe 31, a combustion air pipe 32, a mixing chamber 33, and a fuming furnace duct 34; the SO2 pipe 31 and the combustion air pipe 32 are located on one side of the mixing chamber 33; the fuming furnace duct 34 is located on the other side of the mixing chamber 33 and is symmetrical to the SO2 pipe 31.

[0069] SO2 pipe 31 is connected to SO2 storage tank 2, combustion air pipe 32 is connected to external air, and fumigation furnace air pipe 34 is connected to molten pool.

[0070] In other embodiments, both the SO2 pipe 31 and the combustion air pipe are equipped with check valves 35.

[0071] In some embodiments, a first electrically operated shut-off ball valve 8 is provided between the SO2 drying tower 7 and the SO2 compressor 1;

[0072] A second electrically operated shut-off ball valve 9 is provided between SO2 compressor 1 and SO2 storage tank 2;

[0073] A flow control electric shut-off valve 10 and a flow meter 11 are sequentially installed between SO2 storage tank 2 and fuming furnace 3.

[0074] In some embodiments, a catalytic conversion acid production device 12 is also included;

[0075] The catalytic conversion acid production unit 12 is connected to the outlet of the SO2 drying tower 7, and a third electric shut-off ball valve 13 is provided between the catalytic conversion acid production unit 12 and the SO2 drying tower 7.

[0076] Example 2

[0077] A large tin smelter equipped with a CANSOLV acid production system has an 8m³ unit. 2 Fume treatment furnace. The plant installed fluoropolymer-lined electrically operated shut-off ball valves on the existing pipeline connecting the high-concentration SO2 (content > 99%) produced by the adsorption tower-desorption tower-drying tower to the catalytic conversion acid production equipment. A new pipeline was added after the drying tower to connect to the SO2 compressor, and fluoropolymer-lined electrically operated shut-off ball valves were also installed on the new pipeline. Two 30m³ / h valves were installed after the compressor. 3 Liquid SO2 storage tanks are installed, and fluoropolymer-lined electric shut-off ball valves are installed between the two storage tanks and the compressor. Fluorine-lined electric shut-off valves are installed at the outlets of the two storage tanks. Flow meters are installed on the SO2 conveying pipeline leading to the fuming furnace. All the above electric valves and flow meters are connected to the DCS control system of the fuming furnace. The SO2 collection and storage modification is completed. In actual production, the two SO2 storage tanks are used alternately. When both pressures are filled to 0.55MPa, the SO2 from the rotary kiln, fluidized bed roasting furnace and top blown furnace flue gas of the tin smelting system starts the acid production process. The excess SO2 is connected to the catalytic conversion acid production equipment (13) for normal acid production.

[0078] The SO2 supplied to the fuming furnace passes through an SO2 pipeline equipped with a check valve. It is mixed with the gas from the combustion air pipeline equipped with a check valve in a corrosion-resistant mixing chamber. The mixture is then sprayed into the molten pool of the fuming furnace through the furnace duct for sulfidation and volatilization. During the process, the weak reducing atmosphere is strictly controlled (excess air coefficient 0.8). The sulfided tin produced by sulfidation and volatilization is oxidized into SnO2 and SO2 in the rising channel of the fuming furnace flue gas. After being collected as SnO2 by the bag filter dust collector, the SO2 enters the recycling process, thus realizing the recycling of SO2.

[0079] After completing the renovation to use SO2 as a sulfiding agent in its fuming furnaces, this large tin smelter no longer purchases pyrite as a sulfiding agent. The plant's 8m... 2 The processing capacity of the fuming furnace has been increased from 30t / furnace to 35t / furnace, and the vulcanization time has been shortened from 75min / furnace to 60min / furnace. 8m 2 The fuming furnace processes 35 tons of low-tin material with an average Sn content of 4.29%, consuming 600 Nm³. 3 SO2 volatilization was completed in 60 minutes, resulting in Sn content in the slag being <0.15%, meaning SO2 was volatilized at a rate of 10 Nm³. 3 The mixed combustion air is evenly injected into the furnace energy melting pool from the tuyeres of the fuming furnace at a speed of / min.

[0080] In terms of economy, an 8m 2The fuming furnace consumes 13,200 tons of pyrite annually. By switching to SO2 as the sulfiding agent, the cost of pyrite (calculated at 600 yuan / ton) can be reduced by 7.92 million yuan per year. Using pyrite as the sulfiding agent also increases the amount of slag disposal by 10,000 tons annually. Assuming the slag contains 0.15% Sn, switching to SO2 as the sulfiding agent can reduce the amount of tin carried away by the slag by 15 tons annually, reducing the economic loss of tin by 3.75 million yuan (based on a refined tin price of 250,000 yuan / ton).

[0081] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0082] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A system for using SO2 as a sulfiding agent in a fuming furnace to sulfide volatilized tin, characterized in that, Includes SO2 compressors, SO2 storage tanks, fumigation furnaces, baghouse dust collection devices, and SO2 treatment devices; The SO2 compressor, SO2 storage tank, fumigation furnace, bag filter dust collector, and SO2 treatment device are connected in sequence. The SO2 treatment device consists of an SO2 absorption tower, an SO2 desorption tower, and an SO2 drying tower. The SO2 absorption tower is connected to the bag filter dust collector, and the outlet of the SO2 drying tower is connected to the SO2 compressor. The SO2 absorption tower, SO2 desorption tower, and SO2 drying tower are connected in sequence.

2. The system for sulfiding and volatilizing tin using SO2 as a sulfiding agent in a fumigation furnace according to claim 1, characterized in that, The fuming furnace includes a gas mixing chamber and a molten pool; The gas mixing chamber is connected to the SO2 storage tank, and the molten pool is connected to the bag filter dust collection device; The gas mixing chamber is equipped with an SO2 pipe, a combustion air pipe, a mixing chamber, and a fuming furnace duct; the SO2 pipe and the combustion air pipe are located on one side of the mixing chamber; the fuming furnace duct is located on the other side of the mixing chamber and is symmetrical to the SO2 pipe. The SO2 pipeline is connected to the SO2 storage tank, the combustion air pipeline is connected to the outside air, and the fuming furnace air duct is connected to the molten pool.

3. The system for sulfiding and volatilizing tin using SO2 as a sulfiding agent in a fumigation furnace according to claim 2, characterized in that, Both the SO2 pipeline and the combustion air pipeline are equipped with check valves.

4. The system for sulfiding and volatilizing tin using SO2 as a sulfiding agent in a fumigation furnace according to claim 1, characterized in that, A first electrically operated shut-off ball valve is provided between the SO2 drying tower and the SO2 compressor; A second electrically operated shut-off ball valve is provided between the SO2 compressor and the SO2 storage tank; A flow-controlled electric shut-off valve and a flow meter are sequentially installed between the SO2 storage tank and the fuming furnace.

5. The system for sulfiding and volatilizing tin using SO2 as a sulfiding agent in a fumigation furnace according to claim 1, characterized in that, It also includes catalytic conversion acid production equipment; The catalytic conversion acid production device is connected to the outlet of the SO2 drying tower, and a third electric shut-off ball valve is provided between the catalytic conversion acid production device and the SO2 drying tower.

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