A device and process for continuous extraction of metallic arsenic in a double shaft furnace structure

Abstract

The application discloses a kind of continuous extraction metal arsenic's double shaft furnace structure's device and process, it is related to metallurgical engineering technical field, including flash furnace system, reduction furnace system, multistage condensing system, arsenic collection system, temperature control system and tail gas treatment system, flash furnace system, reduction furnace system, multistage condensing system, temperature control system and tail gas treatment system are sequentially connected by pipeline, arsenic collection system is set in multistage condensing system inside, multistage condensing system includes primary heat exchanger, secondary heat exchanger and tertiary heat exchanger, the inside of primary heat exchanger, secondary heat exchanger and tertiary heat exchanger is equipped with anti-crystallization system, scraping component and slagging component, slagging component is funnel-shaped and is equipped with electric heating wire inside, avoid metal arsenic solidification cooling, solve the condenser in high temperature extraction arsenic process in condensation settlement process, it is easy to produce crystallization blockage, resulting in the speed of metal arsenic condensation precipitation greatly reduces, the problem of affecting processing efficiency.

Description

Technical Field

[0001] This invention relates to the field of metallurgical engineering technology, specifically to a device and process for the continuous extraction of metallic arsenic using a double vertical furnace structure. Background Technology

[0002] In the smelting process of non-ferrous metals, some ores or materials contain high levels of arsenic. This arsenic will be converted into arsenic trioxide during the smelting process. When recycling, it is necessary to extract the metallic arsenic for reuse, which requires the use of appropriate equipment.

[0003] Chinese invention CN102212706A discloses a two-stage carbon reduction method for extracting metallic arsenic from arsenic trioxide raw materials. The method uses arsenic ash or arsenic trioxide as raw materials and kerosene as a reducing agent, with a raw material:reducing agent molar ratio of 1.0:3.0–5.0. The first stage of carbothermic reduction takes place in a closed DC furnace at 800–1300℃ and 0–20 Pa. The resulting metallic arsenic vapor and other flue gases are introduced into a charcoal-filled reduction device outside the furnace for the second stage of carbothermic reduction at 800–1000℃ and 0–20 Pa. The metallic arsenic vapor generated from the two stages of reduction is introduced into a metallic arsenic condensation and settling chamber at 300–500℃ to obtain blocky metallic arsenic. Incompletely reduced arsenic trioxide condenses and settles in a settling tank. However, during this condensation and settling process, the condenser is prone to crystallization blockage during the high-temperature arsenic extraction, significantly reducing the rate of metallic arsenic condensation and precipitation, thus affecting processing efficiency. Summary of the Invention

[0004] The purpose of this invention is to provide an apparatus and process for the continuous extraction of metallic arsenic using a double vertical furnace structure, in order to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A device with a dual vertical furnace structure for continuous extraction of metallic arsenic includes a flash furnace system, a reduction furnace system, a multi-stage condensation system, an arsenic collection system, a temperature control system, and a tail gas treatment system. The flash furnace system, reduction furnace system, multi-stage condensation system, temperature control system, and tail gas treatment system are connected sequentially via pipelines. The arsenic collection system is located inside the multi-stage condensation system, which includes a primary heat exchanger, a secondary heat exchanger, and a tertiary heat exchanger. Each of the primary, secondary, and tertiary heat exchangers is equipped with an anti-crystallization system, a scraping assembly, and a slag discharge assembly. The condensation areas of each of the primary, secondary, and tertiary heat exchangers are equipped with vibrators or electromagnetic vibration modules. The slag discharge assembly is funnel-shaped and has an internal electric heating wire to maintain the outlet temperature above the freezing point of metallic arsenic and prevent blockage.

[0007] Preferably, the flash furnace system includes a silo and a flash furnace. A chiller unit is installed at the front of the silo. The silo and the flash furnace are connected by a pipeline. Arsenic raw material and nitrogen are introduced into the silo. A slag pan is installed on the lower side of the inner wall of the flash furnace. The reduction furnace system includes a reduction furnace and a gasification shaft furnace. The reduction furnace is located above the gasification shaft furnace. The flash furnace, reduction furnace, and primary heat exchanger are connected by a pipeline. The exhaust gases from the flash furnace and reduction furnace are connected to an exhaust gas pipeline.

[0008] Preferably, the scraping assembly includes a central shaft and a servo motor. A connecting rod is fixedly connected to the side of the central shaft, and a scraper is fixedly connected to the end of the connecting rod away from the central shaft. A screw is fixedly connected to the bottom of the central shaft, and a limit slot is formed at the bottom of the screw. A limit ring is fixedly sleeved at the end of the push rod of the servo motor and rotates to engage the inner wall of the limit slot of the screw. A threaded tube is threaded through the screw, and support rods are fixedly connected to both sides of the outer wall of the threaded tube. A protective shell is fixedly connected through the central shaft and the connecting rod. The end of the support rod away from the threaded tube is fixedly connected to the inner wall of the heat exchanger shell. The scraper slides to connect to the inner wall of the condensation area of ​​the heat exchanger. A protective cover is fixedly connected to the top of the servo motor, and vertical rods are fixedly connected to both sides of the top of the protective cover. The top of the vertical rod is fixedly connected to the bottom of the support rod. Controlled by a PLC system, it has periodic rotation and up-and-down floating motion to achieve automatic descaling function.

[0009] Preferably, the anti-crystallization system uses quartz glass, SiC ceramic lining, silicon nitride or alumina ceramic, with the inner wall surface polished and coated with a nano anti-scaling layer. The connecting pipes between the primary, secondary and tertiary heat exchangers are lined with arsenic-resistant ceramic material. The front of the primary heat exchanger is connected to a variable frequency blower via a pipe. The primary, secondary and tertiary heat exchangers are connected to a chiller unit via a water supply pipe and a water return pipe.

[0010] Preferably, the arsenic collection system includes an arsenic collection hopper located on the lower part of the inner wall of the primary, secondary, and tertiary heat exchangers. The primary, secondary, and tertiary heat exchangers are connected to the exhaust gas pipeline via pipes, and an emergency exhaust chimney is installed on the top of the primary heat exchanger.

[0011] Preferably, the temperature control system includes a combustion furnace and an air cooler. The combustion furnace is connected to a three-stage heat exchanger and an air cooler via a pipeline. The combustion furnace is connected to a variable frequency blower via a gas supply pipe. Natural gas is introduced into the combustion furnace. An ash collection hopper is installed on the lower part of the inner wall of the air cooler. The combustion furnace and the air cooler adopt a PID intelligent control module and support segmented independent temperature adjustment and linkage adaptive adjustment.

[0012] Preferably, the exhaust gas treatment system includes a variable frequency induced draft fan, an alkaline scrubbing tower, and a variable frequency exhaust fan. An arsenate collector is installed at the bottom of the alkaline scrubbing tower. The arsenate collector is connected to a chiller unit via a water supply pipe and is supplied with tap water. The air cooler, variable frequency induced draft fan, alkaline scrubbing tower, and variable frequency exhaust fan are all connected by pipes. The alkaline scrubbing tower is connected to an exhaust gas pipeline via a pipe. The rear of the variable frequency exhaust fan is connected to an exhaust gas emission tower.

[0013] Preferably, the condensation process of the multi-stage condensation system adopts a three-stage temperature control structure, and the temperature range can be selected from 400–500℃, 200–300℃, and 30–80℃.

[0014] A continuous extraction process for metallic arsenic using a dual-vertical furnace structure includes arsenic-containing raw material storage, gasification, reduction, condensation, collection, and tail gas purification. The gasification and reduction processes are continuously completed by two vertical furnaces arranged in series. The arsenic raw material is arsenic trioxide powder or arsenic-containing dust, which is fed after granulation or briquetting. The specific steps are as follows:

[0015] S1: Arsenic-containing raw materials are added to the silo and then blown into the flash furnace with nitrogen to quickly turn them into arsenic trioxide vapor;

[0016] S2: Arsenic trioxide vapor enters the reduction furnace through the tail exhaust fan and pipeline;

[0017] S3: Arsenic trioxide vapor reacts in the multi-layer carbon discs in the primary heat exchanger and is reduced by carbon in a reducing atmosphere to generate metallic arsenic vapor, carbon monoxide, and carbon dioxide.

[0018] S4: Arsenic vapor enters the three-stage condensation system through the tail exhaust fan and pipes, where it is condensed and deposited as metallic arsenic in different temperature zones.

[0019] S5: Condensed arsenic is directionally discharged into the arsenic collection system through the scraping and slag discharge components. The system can weigh and automatically pour out the cooled metallic arsenic.

[0020] S6: The exhaust gas treatment system first enters the combustion furnace, where natural gas combustion converts carbon monoxide into carbon dioxide, which is then cooled by an air cooler before entering the variable frequency induced draft fan.

[0021] S7: The variable frequency induced draft fan of the exhaust gas treatment system sends the exhaust gas into the alkaline scrubbing tower to clean the system exhaust gas and environmental exhaust gas before it is discharged through the variable frequency exhaust fan and exhaust stack.

[0022] Compared with the prior art, the beneficial effects of the present invention are:

[0023] This invention reduces crystal adhesion through the selection of materials by incorporating an anti-crystallization system, a scraping component, and a slag discharge component. It mechanically scrapes away the already crystallized arsenic, heats it during the descent process to a temperature higher than the freezing point of arsenic, and finally collects the arsenic in a funnel-shaped slag discharge component for recycling. This solves the problem that during the condensation and settling process, the condenser is prone to crystallization blockage during high-temperature arsenic extraction, which greatly reduces the rate of metallic arsenic condensation and precipitation, thus affecting processing efficiency.

[0024] This invention incorporates a scraping assembly. A servo motor drives a screw to move up or down along the inner wall of a threaded tube. The servo motor's push rod is connected to a limiting opening at the bottom of the screw via a limiting ring. This, combined with the threaded tube, allows the screw to rotate while moving up and down, thereby driving the scraper to rotate and move up and down simultaneously. This scrapes off the arsenic from the condensed area, expanding the scraping area and improving the scraping effect.

[0025] This invention improves the arsenic precipitation effect by setting up a multi-stage condensation system, including a primary heat exchanger, a secondary heat exchanger and a tertiary heat exchanger, with a temperature range selectable in the ranges of 400–500℃, 200–300℃, and 30–80℃, and setting up multi-stage cooling. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the structure and connection of the flash evaporation, reduction and condensation system of the present invention;

[0027] Figure 2 This is a schematic diagram showing the structural connection between the temperature control system and the exhaust gas treatment system of the present invention;

[0028] Figure 3 This is a schematic diagram of the scraping component structure of the present invention;

[0029] Figure 4 This is a schematic diagram showing the disassembly of the scraping component structure of the present invention;

[0030] In the diagram: 1. Central shaft; 2. Connecting rod; 3. Scraper; 4. Screw; 5. Threaded pipe; 6. Support rod; 7. Servo motor; 8. Limit ring; 9. Protective cover; 10. Protective shell; 11. Vertical rod; 12. Chiller unit; 13. Silo; 14. Flash furnace; 15. Reduction furnace; 16. Primary heat exchanger; 17. Secondary heat exchanger; 18. Tertiary heat exchanger; 19. Combustion furnace; 20. Air cooler; 21. Variable frequency induced draft fan; 22. Alkali washing tower; 23. Variable frequency exhaust fan. Detailed Implementation

[0031] The present invention will be further described in detail below with reference to specific embodiments, but the present invention is not limited thereto.

[0032] like Figures 1-4As shown, the present invention provides a device for continuous extraction of metallic arsenic using a dual vertical furnace structure, comprising a flash furnace system, a reduction furnace system, a multi-stage condensation system, an arsenic collection system, a temperature control system, and a tail gas treatment system. The flash furnace system, reduction furnace system, multi-stage condensation system, temperature control system, and tail gas treatment system are sequentially connected via pipelines. The arsenic collection system is located within the multi-stage condensation system, which includes a primary heat exchanger 16, a secondary heat exchanger 17, and a tertiary heat exchanger 18. The internal components of each heat exchanger 18 are equipped with an anti-crystallization system, a scraping assembly, and a slag discharge assembly. The condensation areas of the primary heat exchanger 16, the secondary heat exchanger 17, and the tertiary heat exchanger 18 are all equipped with vibrators or electromagnetic vibration modules. The slag discharge assembly is funnel-shaped and has an electric heating wire installed inside to maintain the outlet temperature above the freezing point of metallic arsenic and prevent blockage. The material selection reduces crystal adhesion, and the already crystallized arsenic is mechanically scraped off. During the falling process, the arsenic is heated to a temperature above the freezing point of arsenic. Finally, the arsenic is collected in the funnel-shaped slag discharge assembly to complete the recovery.

[0033] Furthermore, the flash furnace system includes a silo 13 and a flash furnace 14. A chiller unit 12 is installed at the front of the silo 13. The silo 13 and the flash furnace 14 are connected by a pipeline. Arsenic raw material and nitrogen are introduced into the silo 13. A slag pan is installed on the lower side of the inner wall of the flash furnace 14. The reduction furnace system includes a reduction furnace 15 and a gasification shaft furnace. The reduction furnace 15 is located above the gasification shaft furnace. The flash furnace 14, the reduction furnace 15 and the primary heat exchanger 16 are connected by a pipeline. The exhaust gas from the flash furnace 14 and the reduction furnace 15 is connected to the exhaust gas pipeline. The silo 13 and the chiller unit 12 are used to store raw material powder and transport chilled water. After the flash furnace 14 and the reduction furnace 15 process the arsenic raw material, the arsenic-containing gas is introduced into the primary heat exchanger 16.

[0034] Furthermore, the scraping assembly includes a central shaft 1 and a servo motor 7. A connecting rod 2 is fixedly connected to the side of the central shaft 1. A scraper 3 is fixedly connected to the end of the connecting rod 2 away from the central shaft 1. A screw 4 is fixedly connected to the bottom of the central shaft 1. A limit slot is opened at the bottom of the screw 4. A limit ring 8 is fixedly sleeved at the end of the push rod of the servo motor 7 and rotates to engage with the inner wall of the limit slot of the screw 4. A threaded tube 5 is threaded through the screw 4. Support rods 6 are fixedly connected to both sides of the outer wall of the threaded tube 5. A protective shell 10 is fixedly connected through the central shaft 1 and the connecting rod 2. The end of the support rod 6 away from the threaded tube 5 is fixedly connected to the inner wall of the heat exchanger shell. The scraper 3 is slidably connected to the inner wall of the condensation area of ​​the heat exchanger. A protective cover 9 is fixedly connected to the top of the servo motor 7. Vertical rods 11 are fixedly connected to both sides of the top of the protective cover 9. The top of the vertical rod 11 is fixedly connected to the bottom of the support rod 6. Controlled by a PLC system, it has periodic rotation and up-and-down floating motion to achieve automatic descaling function.

[0035] The servo motor 7 drives the screw 4 to move up or down along the inner wall of the threaded tube 5. The push rod of the servo motor 7 is connected to the limiting opening at the bottom of the screw 4 through the limiting ring 8. Together with the threaded tube 5, the screw 4 can rotate while moving up and down, thereby driving the scraper 3 to rotate and move up and down at the same time, scraping off the arsenic in the condensation area. The protective shell 10 and the protective cover 9 both play a protective and blocking role, preventing arsenic from falling into the threaded tube 5 or contacting the servo motor 7, thus improving the efficiency of arsenic precipitation.

[0036] Furthermore, the anti-crystallization system uses quartz glass, SiC ceramic lining, silicon nitride or alumina ceramic, with the inner wall surface polished and coated with a nano anti-scaling layer. The connecting pipes between the primary heat exchanger 16, the secondary heat exchanger 17 and the tertiary heat exchanger 18 are lined with arsenic-resistant ceramic material. The front of the primary heat exchanger 16 is connected to the variable frequency blower through a pipe. The primary heat exchanger 16, the secondary heat exchanger 17 and the tertiary heat exchanger 18 are connected to the chiller unit 12 through water supply pipes and return pipes. This system is used to assist the crystallized arsenic blocks to detach from the inner wall surface. Combined with the mechanical scraping of the scraping component, it further improves the slag discharge speed of arsenic crystals.

[0037] Furthermore, the arsenic collection system includes an arsenic collection hopper located on the lower inner wall of the primary heat exchanger 16, the secondary heat exchanger 17, and the tertiary heat exchanger 18. The primary heat exchanger 16, the secondary heat exchanger 17, and the tertiary heat exchanger 18 are connected to the exhaust gas pipeline via pipes. An emergency exhaust chimney is installed on the top of the primary heat exchanger 16 for collecting arsenic crystals and discharging exhaust gas.

[0038] Furthermore, the temperature control system includes a combustion furnace 19 and an air cooler 20. The combustion furnace 19 is connected to the three-stage heat exchanger 18 and the air cooler 20 through pipes. The combustion furnace 19 is connected to a variable frequency blower through a gas supply pipe. Natural gas is introduced into the combustion furnace 19. An ash collection hopper is installed on the lower part of the inner wall of the air cooler 20. The combustion furnace 19 and the air cooler 20 adopt a PID intelligent control module and support segmented independent temperature adjustment and linkage adaptive adjustment.

[0039] Furthermore, the exhaust gas treatment system includes a variable frequency induced draft fan 21, an alkaline scrubbing tower 22, and a variable frequency exhaust fan 23. An arsenate collector is installed at the bottom of the alkaline scrubbing tower 22. The arsenate collector is connected to the chiller unit 12 via a water supply pipe and is supplied with tap water. The air cooler 20, the variable frequency induced draft fan 21, the alkaline scrubbing tower 22, and the variable frequency exhaust fan 23 are all connected by pipes. The alkaline scrubbing tower 22 is connected to the exhaust gas pipe via a pipe. The rear of the variable frequency exhaust fan 23 is connected to the exhaust gas emission tower to treat the exhaust gas in a harmless manner before discharging it.

[0040] Furthermore, the condensation process employs a three-stage temperature control structure, with selectable temperature ranges of 400–500℃, 200–300℃, and 30–80℃, enabling multi-stage cooling and improving precipitation efficiency.

[0041] A continuous extraction process for metallic arsenic using a dual-vertical furnace structure includes arsenic-containing raw material storage, gasification, reduction, condensation, collection, and tail gas purification. The gasification and reduction processes are continuously completed by two vertical furnaces arranged in series. The arsenic raw material is arsenic trioxide powder or arsenic-containing dust, which is fed after granulation or briquetting. The specific steps are as follows:

[0042] S1: Arsenic-containing raw materials are added to the silo 13 and blown into the flash furnace 14 with nitrogen to quickly turn them into arsenic trioxide vapor;

[0043] S2: Arsenic trioxide vapor enters the reduction furnace 15 through the tail exhaust fan and pipeline;

[0044] S3: Arsenic trioxide vapor reacts in the multi-layer carbon disks inside the primary heat exchanger 16, and is reduced by carbon in a reducing atmosphere to generate metallic arsenic vapor, carbon monoxide, and carbon dioxide.

[0045] S4: Arsenic vapor enters the three-stage condensation system through the tail exhaust fan and pipes, where it is condensed and deposited as metallic arsenic in different temperature zones.

[0046] S5: Condensed arsenic is directionally discharged into the arsenic collection system through the scraping and slag discharge components. The system can weigh and automatically pour out the cooled metallic arsenic.

[0047] S6: The exhaust gas treatment system first enters the combustion furnace 19, where carbon monoxide is converted into carbon dioxide through natural gas combustion, and then cooled by the air cooler 20 before entering the variable frequency induced draft fan 21.

[0048] S7: The variable frequency induced draft fan 21 of the exhaust gas treatment system sends the exhaust gas into the alkaline scrubbing tower 22, which cleans the system exhaust gas and environmental exhaust gas before discharging it through the variable frequency exhaust fan 23 and the exhaust stack.

Claims

1. A device for continuous extraction of metallic arsenic using a double vertical furnace structure, characterized in that: The system includes a flash furnace system, a reduction furnace system, a multi-stage condensation system, an arsenic collection system, a temperature control system, and a tail gas treatment system. The flash furnace system, reduction furnace system, multi-stage condensation system, temperature control system, and tail gas treatment system are connected sequentially through pipelines. The arsenic collection system is located inside the multi-stage condensation system. The multi-stage condensation system includes a primary heat exchanger (16), a secondary heat exchanger (17), and a tertiary heat exchanger (18). The primary heat exchanger (16), secondary heat exchanger (17), and tertiary heat exchanger (18) are all equipped with an anti-crystallization system, a scraping component, and a slag discharge component. The condensation areas of the primary heat exchanger (16), secondary heat exchanger (17), and tertiary heat exchanger (18) are all equipped with vibrators or electromagnetic vibration modules. The slag discharge component is funnel-shaped and has an electric heating wire installed inside to maintain the outlet temperature above the solidification point of metallic arsenic and prevent blockage.

2. The apparatus for continuous extraction of metallic arsenic using a double vertical furnace structure according to claim 1, characterized in that: The flash furnace system includes a silo (13) and a flash furnace (14). A chiller unit (12) is installed at the front of the silo (13). The silo (13) and the flash furnace (14) are connected by a pipeline. Arsenic raw material and nitrogen are introduced into the silo (13). A slag pan is installed on the lower side of the inner wall of the flash furnace (14). The reduction furnace system includes a reduction furnace (15) and a gasification vertical furnace. The reduction furnace (15) is located above the gasification vertical furnace. The flash furnace (14), the reduction furnace (15) and the primary heat exchanger (16) are connected by a pipeline. The exhaust gas from the flash furnace (14) and the reduction furnace (15) is connected to the exhaust gas pipeline through a pipeline.

3. The apparatus for continuous extraction of metallic arsenic using a double vertical furnace structure according to claim 1, characterized in that: The scraping assembly includes a central shaft (1) and a servo motor (7). A connecting rod (2) is fixedly connected to the side of the central shaft (1). A scraper (3) is fixedly connected to the end of the connecting rod (2) away from the central shaft (1). A screw (4) is fixedly connected to the bottom of the central shaft (1). A limit slot is provided at the bottom of the screw (4). A limit ring (8) is fixedly sleeved on the end of the push rod of the servo motor (7) and rotates to engage the inner wall of the limit slot of the screw (4). A threaded tube (5) is threaded through the screw (4). Supports are fixedly connected to both sides of the outer wall of the threaded tube (5). The rod (6), the central shaft (1) and the connecting rod (2) are fixedly connected to the protective shell (10), the end of the support rod (6) away from the threaded tube (5) is fixedly connected to the inner wall of the heat exchanger shell, the scraper (3) is slidably connected to the inner wall of the condensation area of ​​the heat exchanger, the top of the servo motor (7) is fixedly connected to the protective cover (9), the top two sides of the protective cover (9) are fixedly connected to the vertical rod (11), the top of the vertical rod (11) is fixedly connected to the bottom of the support rod (6), and it is controlled by the PLC system to have periodic rotation and up and down floating motion to realize automatic descaling function.

4. The apparatus for continuous extraction of metallic arsenic using a double vertical furnace structure according to claim 2, characterized in that: The anti-crystallization system uses quartz glass, SiC ceramic lining, silicon nitride or alumina ceramic, with the inner wall surface polished and coated with a nano anti-scaling layer. The connecting pipes between the primary heat exchanger (16), the secondary heat exchanger (17) and the tertiary heat exchanger (18) are lined with arsenic-resistant ceramic material. The front of the primary heat exchanger (16) is connected to the variable frequency blower through a pipe. The primary heat exchanger (16), the secondary heat exchanger (17) and the tertiary heat exchanger (18) are connected to the chiller unit (12) through the water supply pipe and the water return pipe.

5. The apparatus for continuous extraction of metallic arsenic using a double vertical furnace structure according to claim 4, characterized in that: The arsenic collection system includes an arsenic collection hopper located on the lower inner wall of the primary heat exchanger (16), the secondary heat exchanger (17), and the tertiary heat exchanger (18). The primary heat exchanger (16), the secondary heat exchanger (17), and the tertiary heat exchanger (18) are connected to the exhaust gas pipeline via pipes. An emergency exhaust chimney is installed on the top of the primary heat exchanger (16).

6. The apparatus for continuous extraction of metallic arsenic using a double vertical furnace structure according to claim 4, characterized in that: The temperature control system includes a combustion furnace (19) and an air cooler (20). The combustion furnace (19) is connected to a three-stage heat exchanger (18) and an air cooler (20) through a pipeline. The combustion furnace (19) is connected to a variable frequency blower through a gas pipeline. Natural gas is introduced into the combustion furnace (19). An ash collection hopper is installed on the lower part of the inner wall of the air cooler (20). The combustion furnace (19) and the air cooler (20) adopt a PID intelligent control module and support segmented independent temperature adjustment and linkage adaptive adjustment.

7. The apparatus for continuous extraction of metallic arsenic using a double vertical furnace structure according to claim 6, characterized in that: The exhaust gas treatment system includes a variable frequency induced draft fan (21), an alkaline scrubbing tower (22), and a variable frequency exhaust fan (23). An arsenate collector is installed at the bottom of the alkaline scrubbing tower (22). The arsenate collector is connected to the chiller unit (12) through a water supply pipe and is supplied with tap water. The air cooler (20), the variable frequency induced draft fan (21), the alkaline scrubbing tower (22), and the variable frequency exhaust fan (23) are all connected by pipes. The alkaline scrubbing tower (22) is connected to the exhaust gas pipe through a pipe. The rear of the variable frequency exhaust fan (23) is connected to the exhaust gas emission tower.

8. The apparatus for continuous extraction of metallic arsenic using a double vertical furnace structure according to claim 1, characterized in that: The condensation process of the multi-stage condensation system adopts a three-stage temperature control structure, with a selectable temperature range of 400–500℃, 200–300℃, and 30–80℃.

9. A processing method for continuous extraction of metallic arsenic using a double vertical furnace structure employing the apparatus described in any one of claims 1 to 8, characterized in that, The process includes the storage, gasification, reduction, condensation, collection, and tail gas purification of arsenic-containing raw materials. The gasification and reduction processes are continuously completed by two vertical furnaces arranged in series. The arsenic raw material is arsenic trioxide powder or arsenic-containing dust, which is fed after granulation or briquetting. The specific steps are as follows: S1: Arsenic-containing raw materials are added to the silo (13) and blown into the flash furnace (14) by nitrogen gas, which quickly turns them into arsenic trioxide vapor; S2: Arsenic trioxide vapor enters the reduction furnace (15) through the tail exhaust fan and pipeline. S3: Arsenic trioxide vapor reacts in the multi-layer carbon disks inside the primary heat exchanger (16) and is reduced by carbon in a reducing atmosphere to generate metallic arsenic vapor, carbon monoxide, and carbon dioxide; S4: Arsenic vapor enters the three-stage condensation system through the tail exhaust fan and pipes, where it is condensed and deposited as metallic arsenic in different temperature zones. S5: Condensed arsenic is directionally discharged into the arsenic collection system through the scraping and slag discharge components. The system can weigh and automatically pour out the cooled metallic arsenic. S6: The exhaust gas treatment system first enters the combustion furnace (19), where carbon monoxide is converted into carbon dioxide through natural gas combustion, and then cooled by the air cooler (20) before entering the variable frequency induced draft fan (21). S7: The variable frequency induced draft fan (21) of the exhaust gas treatment system sends the exhaust gas into the alkaline scrubbing tower (22) to clean the system exhaust gas and environmental exhaust gas before discharging it through the variable frequency exhaust fan (23) and exhaust stack.

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