A method and apparatus for treating flue dust

Abstract

The present application belongs to the field of additive manufacturing, and relates to a smoke dust treatment method and equipment. The smoke dust treatment method is a process of sequentially mixing metal smoke dust to be purified with inert substances in a low-oxygen or oxygen-free environment, so as to promote the contact between the inert substances and metal particles in the metal smoke dust and form a physically combined mixture, and then gradually reduce the concentration of the metal particles in the metal smoke dust to be purified. The metal smoke dust is derived from an additive manufacturing process. The present application provides a smoke dust treatment method and equipment which can improve overall operation safety and facilitate maintenance.

Description

Technical Field

[0001] This invention belongs to the field of additive manufacturing and relates to a method and equipment for treating dust, and more particularly to a method and equipment for treating dust. Background Technology

[0002] In the metal additive manufacturing process, metal fumes containing metal powder particles and / or metal condensates (black slag) generated during the process are often produced. These fumes have a very low minimum ignition energy and are highly flammable, thus requiring specialized dust collection devices for dust removal, collection, transfer, or storage in a safe environment. Conventional dust collection devices primarily use an inert gas atmosphere to prevent dust from reacting with oxygen, thus preventing combustion by isolating oxidizers. However, this type of dust collection device presents challenges in maintenance, including difficulties and hazards. When replacing the dust collection bin containing combustible dust, the dust is highly susceptible to contact with oxygen, potentially leading to combustion or even explosion; similarly, replacing the filter element also carries the risk of explosion due to the filter element coming into contact with oxygen. Conventional dust collection devices employ liquid passivation, filling the dust collection bin / filter box with water or other liquids for passivation before proceeding with other maintenance steps. However, this method requires significant manpower and material resources and is unsuitable for aluminum / aluminum alloy powders. Natural incineration is also a common treatment method, which involves placing the dust collection bin / filter box in a safe area and allowing it to react fully with oxygen to generate low-activity oxide dust. However, this method is highly dangerous, has high site requirements, is not environmentally friendly, and results in the filter / dust collection bin not being reusable or having a reduced lifespan. Summary of the Invention

[0003] In order to solve the above-mentioned technical problems in the background art, the present invention provides a method and equipment for treating smoke and dust that can improve overall operational safety and facilitate maintenance.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] A method for treating fume, characterized in that: the fume treatment method involves physically combining the metal fume to be purified with an inert compound in a time-sequential mixing manner in a low-oxygen or oxygen-free environment, thereby promoting the inert compound to contact with the metal particles of the metal fume and forming a physically combined mixture, thereby gradually reducing the concentration of metal particles in the metal fume to be purified; the metal fume originates from an additive manufacturing process.

[0006] The specific implementation of the above-mentioned fume treatment method is as follows: In a low-oxygen or oxygen-free environment, the metal fume to be purified is placed in a flow process, and a fluid inert material is added sequentially to promote contact between the fluid inert material and the metal particles of the metal fume to be purified. The fluid inert material performs initial physical purification on the metal particles of the metal fume, resulting in a primary purification product. The primary purification product is then introduced into a static inert material along with the circulating metal fume to be purified. This causes the static inert material to simultaneously contact the metal particles of the metal fume that have not undergone physical purification in the primary purification product and the metal particles of the metal fume to be purified, resulting in a second physical bonding and forming a physically bonded mixture. This gradually reduces the concentration of metal particles in the metal fume to be purified. Preferably, the primary purification product includes a mixture that has undergone physical purification, fluid inert material that has not undergone physical purification, and metal fume that has not undergone physical purification. The mixture that has undergone physical purification is a mixture formed by fluid inert material and metal particles in the metal fume.

[0007] The aforementioned fluid-like inert material is a fluid formed directly from an inert material or a fluid formed by attaching an inert material to a flowing carrier; preferably, the flowing carrier is a conveying airflow; the conveying airflow is a clean airflow or metal fumes to be purified.

[0008] The above-mentioned dust treatment method also includes a step of sieving physically bound mixtures; preferably, the sieving method is filtration and / or cyclone separation.

[0009] The above-mentioned fume treatment method further includes a physical separation step; the physical separation step is a step of physically separating the metal fume to be purified before physical bonding and / or a step of physically separating the metal fume with reduced metal particle concentration after sieving the physically bonded mixture; the physical separation method is filtration and / or cyclone separation; preferably, the filtration is a filter element and / or filter screen; the cyclone separation is cyclone separation and / or mechanical labyrinth; the inerting agent is calcium carbonate powder.

[0010] A fume treatment device for implementing the fume treatment method described above, characterized in that: the fume treatment device includes at least a physical bonding device; the physical bonding device includes a reaction chamber; the reaction chamber is located in a low-oxygen or oxygen-free environment; the reaction chamber is provided with a fume inlet and a clean gas outlet; both the material tank and the inside of the reaction chamber are filled with inert material; the material tank is in communication with the fume inlet; the inert material in the material tank is sequentially mixed with the metal fume to be purified and then injected into the reaction chamber, impacting the inert material inside the reaction chamber to achieve physical bonding; the purified metal fume is discharged through the clean gas outlet.

[0011] The aforementioned physical combination device also includes a pneumatic conveying device; the inerting material in the material barrel is sequentially conveyed by the pneumatic conveying device to the flow channel of the metal fumes to be purified and mixed with the metal fumes to be purified; preferably, the pneumatic conveying device includes a fluid channel, a fluid conveying device, and a compressed gas supply device for generating compressed gas; the compressed gas supply device is connected to the flow channel of the metal fumes to be purified through the fluid channel and the fluid conveying device; the inerting material in the material barrel is connected to the fluid channel; preferably, the fluid conveying device is a plunger pump, a gear pump, a Roots vacuum pump, a vacuum generator, or a blower.

[0012] The aforementioned physical bonding device also includes a filtration device placed inside the reaction chamber. The mixture generated after the metal fumes to be purified physically bond with the inert material inside the reaction chamber is intercepted by the filtration device. The purified metal fumes are discharged sequentially through the filtration device and the clean gas outlet. Preferably, the filtration device is a filter screen, a filter element, and / or a cyclone separator.

[0013] The aforementioned physical combination device also includes a material feeding mechanism; the inert material placed in the material bucket is mixed with the metal fumes to be purified in a sequential manner through the material feeding mechanism; preferably, the material feeding mechanism is a rotary valve, butterfly valve, slide gate valve or venturi tube.

[0014] The reaction chamber described above is either an integral structure or a split structure; when the reaction chamber is an integral structure, a slag discharge port is provided at the bottom of the reaction chamber; preferably, the slag discharge port is connected to the material tank; when the reaction chamber is a split structure, the reaction chamber includes a fixing component and a detachable component movably connected to the fixing component; the filtration device is placed in the fixing component.

[0015] The aforementioned dust treatment equipment also includes a physical separation device connected to the physical combination device; the dust purified by the physical combination device is separated by the physical separation device and discharged from the top of the physical separation device; preferably, the bottom of the physical separation device is connected to the dust inlet through a material discharge mechanism; preferably, the physical separation device includes a fan and a separation device; the separation device is connected to the fan; the dust purified by the physical combination device is separated by the separation device and discharged from the top of the separation device; the bottom of the separation device is connected to the dust inlet through a material discharge mechanism; preferably, the separation device is a filter element, a filter screen, a cyclone separator, and / or a mechanical labyrinth.

[0016] The aforementioned fume treatment equipment also includes a feed tank filled with inert material; the feed tank is connected to the fume inlet via a feeding mechanism; the inert material in the feed tank is sequentially mixed with the metal fume to be purified and then injected into the reaction chamber; the feed tank is provided with a pressure replenishing pipe connected to the clean airflow or the purified metal fume; preferably, the feed tank is an integral structure or a replaceable structure; preferably, when the feed tank is an integral structure, the feed tank is provided with an openable feed port.

[0017] The advantages of this invention are:

[0018] This invention provides a method and apparatus for treating fume extraction. The method involves physically combining metal fumes from additive manufacturing processes with an inert compound through a sequential mixing process in a low-oxygen or oxygen-free environment. This process promotes contact between the inert compound and the metal particles in the fume, forming a physically bonded mixture, thereby gradually reducing the concentration of metal particles in the fume. By first sequentially mixing the metal fumes with the inert compound at the fume inlet, and then injecting the mixture into the reaction chamber for thorough mixing with the inert compound inside, the invention transforms the low-ignition-energy metal fumes into a high-ignition-energy mixture. This significantly reduces the reactivity of the metal fumes, greatly improving safety and achieving intrinsic safety; even if the collected dust is placed in air, it will not burn. Furthermore, this invention eliminates the need for additional water injection or ignition treatments, extending the lifespan of the metal fume extraction equipment, reducing maintenance costs, and simplifying maintenance. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the dust treatment equipment (self-blowing type) provided by the present invention;

[0020] Figure 2 This is a schematic diagram of the structure of the dust treatment equipment (airflow compensation type) provided by the present invention;

[0021] Figure 3 This is a schematic diagram of a preferred embodiment of the dust treatment equipment provided by the present invention;

[0022] Figure 4 This is a schematic diagram of the overall structure of the dust treatment equipment provided by the present invention;

[0023] in:

[0024] 1-Fume inlet; 2-Clean gas outlet; 3-Filtration equipment; 4-Fluid channel; 5-Feeding mechanism; 6-Ash bucket; 7-Inertizer; 8-Reaction chamber; 9-Fluid conveying equipment; 10-Feeding bucket; 11-Pressure replenishment pipe; 12-Fan; 13-Separation equipment. Detailed Implementation

[0025] This invention provides a method for treating fume, which involves physically combining metal fumes from additive manufacturing processes with an inert compound in a time-sequential mixing manner in a low-oxygen or oxygen-free environment. This process promotes contact between the inert compound and the metal particles of the fume, forming a physically bonded mixture, thereby gradually reducing the concentration of metal particles in the fume to be purified. Specifically, the dust treatment method provided by this invention is implemented in a low-oxygen or oxygen-free environment, where the metal dust to be purified is placed in a flow process, and a fluid inert material is added sequentially to promote contact between the fluid inert material and the metal particles of the metal dust to be purified. The fluid inert material performs initial physical purification on the metal particles of the metal dust, resulting in an initial purified product. The initial purified product is then introduced into a static inert material along with the circulating metal dust to be purified, causing the static inert material to simultaneously contact the metal particles of the metal dust that have not undergone physical purification in the initial purified product and the metal particles of the metal dust to be purified, resulting in a second physical bonding and forming a physically bonded mixture, thereby gradually reducing the concentration of metal particles in the metal dust to be purified. Preferably, the initial purified product includes a mixture that has undergone physical purification, fluid inert material that has not undergone physical purification, and metal dust that has not undergone physical purification; wherein, the mixture that has undergone physical purification is a mixture formed by fluid inert material and metal particles in the metal dust.

[0026] This invention mixes the inert material with the metal fumes to be purified in a sequential manner before introducing it into the inert material. By mixing them sequentially, the probability of contact between the metal fumes to be purified and the inert material is increased, which can make the metal fumes to be purified fully combined with the inert material. This avoids problems such as insufficient inert material and can directly improve the efficiency of fume treatment, improve the printing quality of parts and printing efficiency.

[0027] The fluid inert material is a fluid formed directly from an inert material or a fluid formed by attaching an inert material to a flowing carrier; preferably, the flowing carrier is a conveying airflow; the conveying airflow is a clean airflow or metal fumes to be purified.

[0028] The fume treatment method also includes a step of sieving physically bound mixtures; for example, the sieving method is filtration and / or cyclone separation, through which the mixture of metal fumes and inert substances can be isolated.

[0029] Furthermore, the fume treatment method provided by the present invention also includes a physical separation step; the physical separation step is a step of physically separating the metal fume to be purified before physical bonding and / or a step of physically separating the metal fume with reduced metal particle concentration after sieving the physically bonded mixture; the physical separation method is filtration and / or cyclone separation; preferably, filtration is a filter element and / or filter screen; cyclone separation is cyclone separation and / or mechanical labyrinth; the inerting agent is calcium carbonate powder.

[0030] The present invention also provides a dust treatment apparatus for implementing the aforementioned dust treatment method, the dust treatment apparatus comprising at least a physical bonding device, exemplarily, see [link to relevant documentation]. Figure 1 The physical bonding device includes a reaction chamber 8; the reaction chamber 8 is located in a low-oxygen or oxygen-free environment; the reaction chamber 8 is equipped with a dust inlet 1 and a clean gas outlet 2; both the material tank 6 and the inside of the reaction chamber 8 are filled with inert material 7; the material tank 6 is connected to the dust inlet 1; the inert material 7 in the material tank 6 is sequentially mixed with the metal dust to be purified and then injected into the reaction chamber 8, impacting the inert material inside the reaction chamber 8 to achieve physical bonding; the purified metal dust is discharged through the clean gas outlet 2. That is, Figure 1 The dust treatment equipment shown relies on the gravity flow of inert material 7 in the material tank 6 to the metal dust to be purified. The metal dust to be purified sequentially picks up and carries away the inert material 7 in the material tank 6, and finally introduces it into the reaction chamber 8. It is fully mixed with the inert material 7 in the reaction chamber 8, which greatly reduces the reactivity of the collected dust and makes it difficult to burn in the air, thereby improving the safety of the dust treatment equipment.

[0031] See Figure 1In practical use, the physical bonding device employed in this invention involves adding inert material 7 into the ash bucket 6 or directly into the reaction chamber 8, and using a valve (such as a butterfly valve or a slide valve) between the ash bucket 6 and the reaction chamber 8 to add it into the ash bucket 6. Before starting the purification of the metal fumes to be purified, the circulating air is activated. The circulating air enters through the fume inlet 1, flows through the fluid channel 4 into the reaction chamber 8, and finally exits through the clean air outlet 2. During the activation of the circulating air, the inert material 7 placed in the ash bucket 6 or the inert material 7 placed in the reaction chamber 8 falls into the fluid channel 4 via the material dropping device 5, and is then blown towards the reaction chamber 8 by the circulating air, covering the surface of the reaction chamber 8 and its internal filter device 3 with the inert material 7. After the reaction chamber 8 and its internal filter 3 are covered with a layer of inert material 7, the purification of the metal fumes to be purified begins. Circulating air carries the metal fumes to be purified into the fluid channel 4 through the fume inlet 1. Simultaneously, the inert material 7 placed in the ash bin 6 or in the reaction chamber 8 falls sequentially into the fluid channel 4 via the discharge device 5, where it is swept up by the flowing metal fumes and simultaneously blown onto the filter 3 in the reaction chamber 8. Under certain conditions (condition a: filter 3 is saturated; condition b: the inert material in the ash bin 6...), the purification process continues. Once the inerting agent 7 is completely consumed, the flow of circulating air from the dust inlet 1 is stopped, the material discharge device 5 is closed, and the sequential descent of the inerting agent 7 placed in the ash bucket 6 or the reaction chamber 8 is stopped. The filter device 3 is then cleaned (by backflushing the filter device 3; for example, the filter can be kept running during backflushing, allowing the deposits on the filter device 3 to fall into the reaction chamber 8; alternatively, methods other than backflushing, such as mechanical scraping or mechanical vibration, can be used), causing the inerting agent and dust on the filter device 3 to fall back into the reaction chamber 8. After the inerting agent and dust on the filter device 3 are cleaned back into the reaction chamber 8, the metal dust to be purified is reintroduced into the dust inlet 1, and the aforementioned steps are repeated until the proportion of dust in the inerting agent reaches a preset ratio. Subsequently, the mixture generated after physical bonding in the reaction chamber 8 is discharged or temporarily stored in an empty ash bucket 6, completing the purification treatment of the metal dust to be purified. When a new round of purification needs to be started, replace the ash bucket 6 or add new pure inert material to the ash bucket 6, and then carry out the purification process as described above.

[0032] To improve the flowability of the inert material 7 within the material container 6, the physical bonding device provided by this invention also includes a pneumatic conveying device. This device sequentially conveys the inert material 7 from the material container 6 to the flow channel of the metal fumes to be purified, where it mixes with the fumes. For example, see... Figure 2The pneumatic conveying equipment includes a fluid channel 4, a fluid conveying device 9, and a compressed gas supply device for generating compressed gas, wherein the compressed gas includes, but is not limited to, argon and nitrogen. That is, the pneumatic conveying equipment used in this invention can be a combination of the fluid channel 4 and the fluid conveying device 9, or a combination of the fluid channel 4 and the compressed gas supply device; or a combination of the fluid channel 4 with both the fluid conveying device 9 and the compressed gas supply device. The compressed gas supply device is connected to the flow channel of the metal fume to be purified through the fluid channel 4 and the fluid conveying device 9; the inerting material 7 in the material tank 6 is connected to the fluid channel 4. For example, the fluid conveying device 9 can be a plunger pump, a gear pump, a Roots vacuum pump, a vacuum generator, or a fan, or it can be a mechanical conveying mechanism, such as a screw conveyor (commonly known as an auger).

[0033] See Figure 2In practical use, the physical bonding device used in this invention adds inert material 7 into the ash bucket 6 or directly into the reaction chamber 8, and uses a valve (such as a butterfly valve or a slide valve) between the ash bucket 6 and the reaction chamber 8 to add it into the ash bucket 6. Before the metal fume to be purified is purified, the inert material 7 placed in the ash bucket 6 or the inert material 7 placed in the reaction chamber 8 is dropped into the fluid channel 4 by the material dropping device 5 through the pneumatic conveying device. Then it is blown towards the reaction chamber 8 by the circulating air, and the inert material 7 covers the surface of the reaction chamber 8 and its internal filter device 3. After the reaction chamber 8 and its internal filter 3 are covered with a layer of inert material 7, the purification process for the metal fumes to be purified begins. The metal fumes are injected into the fume inlet 1, and simultaneously, the inert material 7 placed in the ash bin 6 or the reaction chamber 8 is sequentially drawn into the fluid channel 4 via the material discharge device 5 using pneumatic conveying. This material then merges with the metal fumes and is simultaneously blown onto the filter 3 in the reaction chamber 8. The purification process continues until certain conditions are met (condition a: filter 3 is saturated; condition b: all inert material 7 in the ash bin 6 is consumed). After the desired effect is achieved, the circulating air from the dust inlet 1 is stopped, the material discharge device 5 is closed, and the sequential descent of the inert material 7 placed in the ash bin 6 or the reaction chamber 8 is stopped. The filter device 3 is then cleaned (by backflushing the filter device 3; for example, a strong airflow is used to backflush the filter device 3, causing the deposits on the filter device 3 to fall into the reaction chamber 8; other methods besides backflushing, such as mechanical scraping or mechanical vibration, can also be used; the filter can be shut down during backflushing). This allows the inert material and dust on the filter device 3 to fall back into the reaction chamber 8. After the inert material and dust on the filter device 3 are cleaned back into the reaction chamber 8, the metal dust to be purified is reintroduced into the dust inlet 1, and the aforementioned steps are repeated until the proportion of dust in the inert material reaches the preset ratio. The mixture generated after physical bonding in the reaction chamber 8 is then discharged or temporarily stored in an empty ash bin 6, completing the purification process for the metal dust to be purified. When a new round of purification needs to be started, replace the ash bucket 6 or add new pure inert material to the ash bucket 6, and then carry out the purification process as described above.

[0034] See Figure 1 as well as Figure 2 The physical bonding device used in this invention also includes a filter device 3 placed inside the reaction chamber 8. The mixture generated after the metal fume to be purified physically bonds with the inerting agent 7 inside the reaction chamber 8 is intercepted by the filter device 3. The purified metal fume is then discharged sequentially through the filter device 3 and the clean gas outlet 2. For example, the filter device 3 can be a filter screen, a filter element, and / or a cyclone separator. The filter device 3 can perform physical isolation, which can significantly reduce the concentration of inerting agent 7, metal particles, or the mixture generated after physical bonding in the purified metal fume.

[0035] See also Figure 1 as well as Figure 2 The physical bonding device used in this invention also includes a feeding mechanism 5; the inert material 7 placed in the material bucket 6 is mixed with the metal fumes to be purified in a sequential manner through the feeding mechanism 5. For example, the feeding mechanism 5 can be a rotary valve, a butterfly valve, a slide gate valve, or a venturi tube.

[0036] The reaction chamber 8 used in this invention can be an integral structure or a split structure. When the reaction chamber 8 is an integral structure, a slag discharge port is provided at the bottom of the reaction chamber 8, through which the mixture generated after physical bonding can be discharged, or the slag discharge port can be connected to the material tank 6 (e.g., Figure 1 As shown in the diagram, before physical bonding, material tank 6 is filled with inerting agent 7. As time progresses, the inerting agent 7 in material tank 6 is gradually depleted, forming an empty tank. At this point, it can serve as a temporary storage tank for the mixture generated after physical bonding. This measure is used to temporarily store, transfer, or further process the mixture generated after physical bonding. In other words, the function of material tank 6 is as a transfer station for the circulation of inerting agent 7 and a transfer container for storing and retrieving inerted ash residue, which can better ensure the air pressure balance during the transportation of inerting agent 7. When the reaction chamber 1 is a split structure, the reaction chamber 8 includes a fixed component and a detachable component movably connected to the fixed component; the detachable component is used to temporarily store the mixture generated after physical bonding. The filtration device is placed in the fixed component.

[0037] See Figure 3 as well as Figure 4 The fume treatment equipment provided by this invention also includes a physical separation device connected to the physical bonding device; the fume purified by the physical bonding device is separated by the physical separation device and discharged from the top of the physical separation device. This invention, through the combination of a physical bonding device and a physical separation device, further improves the treatment efficiency of the metal fume to be purified. For example, see... Figure 3 as well as Figure 4 The bottom of the physical separation device is connected to the dust inlet 1 via a material discharge mechanism 5. The physical separation device includes a fan 12 and a separation device 13; the separation device 13 is connected to the fan 12; after purification by the physical separation device, the dust is discharged from the top of the separation device 13; the bottom of the separation device 13 is connected to the dust inlet 1 via the material discharge mechanism 5. Preferably, the separation device 13 is a filter element, filter screen, cyclone separator, and / or mechanical labyrinth; alternatively, the separation device 13 is a filter box of a conventional dust removal device, a sintered plate filter box with a back-blowing device, a filter box with a bag filter element, or a filter box with a cylindrical filter element, as long as it can achieve the expected dust filtration effect. The fan 12 is preferably a centrifugal fan, but other types of fans or air pumps can be selected according to air volume, pressure, or other requirements.

[0038] See Figure 4 To extend the processing capacity of the metal fumes to be purified, the fume treatment equipment provided by this invention also includes a feeding tank 10 filled with inert material 7. The feeding tank 10 replenishes the inert material 7 required during the fume treatment process in a timely manner, avoiding downtime during the purification process. The feeding tank 10 is connected to the fume inlet 1 via a feeding mechanism 5. The inert material 7 in the feeding tank 10 is mixed with the metal fumes to be purified in a timely manner and then injected into the reaction chamber 8. The feeding tank 10 is equipped with a pressure-replenishing pipe 11 that is connected to the clean airflow or the purified metal fumes. The pressure-replenishing pipe 11 provides pressure to the feeding tank 10, ensuring that the inert material 7 in the feeding tank 10 falls smoothly into the feeding mechanism 5, and preventing the inert material 7 from failing to fall due to reduced or insufficient pressure in the feeding tank 10. For example, the feeding tank 10 is an integral or replaceable structure; preferably, when the feeding tank 10 is an integral structure, it is provided with an openable feeding port. For example, opening valves are provided between the physical separation device and the feeding mechanism 5, and between the feeding tank 10 and the feeding mechanism 5. The opening valves are any valves that can control the opening and closing of the pipeline, such as butterfly valves, gate valves, ball valves, pinch valves, rotary valves, and stop valves. Among them, the butterfly valve is the preferred structure of the present invention, but it does not mean that this solution can only use butterfly valves.

Claims

1. A method for treating smoke and dust, characterized in that: The fume treatment method involves physically combining the metal fume to be purified with an inert compound in a time-sequential mixing manner in a low-oxygen or oxygen-free environment. This process promotes the contact between the inert compound and the metal particles of the fume to form a physically combined mixture, thereby gradually reducing the concentration of metal particles in the fume to be purified. The metal fume originates from additive manufacturing.

2. The method for treating smoke and dust according to claim 1, characterized in that: The specific implementation of the fume treatment method is as follows: In a low-oxygen or oxygen-free environment, the metal fume to be purified is placed in a flow process, and a fluid inert material is added sequentially to promote contact between the fluid inert material and the metal particles of the metal fume to be purified. The fluid inert material performs initial physical purification on the metal particles of the metal fume, resulting in an initial purification product. The initial purification product is then introduced into a static inert material along with the circulating metal fume to be purified. This causes the static inert material to simultaneously contact the metal particles of the metal fume that have not undergone physical purification in the initial purification product and the metal particles of the metal fume to be purified, resulting in a second physical bonding and forming a physically bonded mixture. This gradually reduces the concentration of metal particles in the metal fume to be purified. Preferably, the initial purification product includes a mixture that has undergone physical purification, fluid inert material that has not undergone physical purification, and metal fume that has not undergone physical purification. The mixture that has undergone physical purification is a mixture formed by fluid inert material and metal particles in the metal fume.

3. The method for treating smoke and dust according to claim 2, characterized in that: The fluid inert material is a fluid formed directly from an inert material or a fluid formed by attaching an inert material to a flowing carrier; preferably, the flowing carrier is a conveying airflow; the conveying airflow is a clean airflow or metal fumes to be purified.

4. The method for treating smoke and dust according to claim 1, 2, or 3, characterized in that: The dust treatment method further includes a step of sieving physically bound mixtures; preferably, the sieving method is filtration and / or cyclone separation.

5. The method for treating smoke and dust according to claim 4, characterized in that: The fume treatment method further includes a physical separation step; the physical separation step is a step of physically separating the metal fume to be purified before physical bonding and / or a step of physically separating the metal fume with reduced metal particle concentration after sieving the physically bonded mixture; the physical separation method is filtration and / or cyclone separation; preferably, the filtration is a filter element and / or a filter screen; the cyclone separation is cyclone separation and / or a mechanical labyrinth.

6. A dust treatment apparatus for implementing the dust treatment method according to any one of claims 1-5, characterized in that: The fume treatment device includes at least a physical bonding device; the physical bonding device includes a reaction chamber (8); the reaction chamber (8) is in a low-oxygen or oxygen-free environment; the reaction chamber (8) is provided with a fume inlet (1) and a clean gas outlet (2); the material bucket (6) and the reaction chamber (8) are both filled with inert material (7); the material bucket (6) is connected to the fume inlet (1); the inert material (7) in the material bucket (6) is mixed with the metal fume to be purified in sequence and then injected into the reaction chamber (8) and impacts the inert material inside the reaction chamber (8) to achieve physical bonding, and the purified metal fume is discharged through the clean gas outlet (2).

7. The dust treatment equipment according to claim 6, characterized in that: The physical bonding device also includes a pneumatic conveying device; the inerting material (7) in the material barrel (6) is sequentially conveyed to the flow channel of the metal fume to be purified by the pneumatic conveying device and mixed with the metal fume to be purified; preferably, the pneumatic conveying device includes a fluid channel (4), a fluid conveying device (9) and a compressed gas supply device for generating compressed gas; the compressed gas supply device is connected to the flow channel of the metal fume to be purified through the fluid channel (4) and the fluid conveying device (9); the inerting material (7) in the material barrel (6) is connected to the fluid channel (4); preferably, the fluid conveying device (9) is a plunger pump, a gear pump, a Roots vacuum pump, a vacuum generator or a blower.

8. The dust treatment equipment according to claim 7, characterized in that: The physical bonding device also includes a filter device (3) placed inside the reaction chamber (8). The mixture generated after the metal fume to be purified and the inert material (7) inside the reaction chamber (8) are physically bonded is intercepted by the filter device (3). The purified metal fumes are discharged sequentially through the filtration device (3) and the clean gas outlet (2); preferably, the filtration device (3) is a filter screen, a filter element and / or a cyclone separator.

9. The dust treatment equipment according to claim 8, characterized in that: The physical bonding device also includes a material feeding mechanism (5); the inert material (7) placed in the material bucket (6) is mixed with the metal dust to be purified in sequence through the material feeding mechanism (5); preferably, the material feeding mechanism (5) is a rotary valve, butterfly valve, slide gate valve or venturi tube.

10. The dust treatment equipment according to claim 9, characterized in that: The reaction chamber (8) is an integral structure or a split structure; when the reaction chamber (8) is an integral structure, a slag discharge port is provided at the bottom of the reaction chamber (8); preferably, the slag discharge port is connected to the material bucket (6); when the reaction chamber (1) is a split structure, the reaction chamber (8) includes a fixing component and a detachable component that is movably connected to the fixing component; the filter device is placed in the fixing component.

11. The dust treatment equipment according to any one of claims 6-10, characterized in that: The dust treatment equipment also includes a physical separation device connected to the physical combination device; the dust purified by the physical combination device is separated by the physical separation device and discharged from the top of the physical separation device; preferably, the bottom of the physical separation device is connected to the dust inlet (1) through a material dropping mechanism (5); preferably, the physical separation device includes a fan (12) and a separation device (13); the separation device (13) is connected to the fan (12); the dust purified by the physical combination device is separated and discharged from the top of the separation device (13); the bottom of the separation device (13) is connected to the dust inlet (1) through a material dropping mechanism (5); preferably, the separation device (13) is a filter element, a filter screen, a cyclone separator and / or a mechanical labyrinth.

12. The dust treatment equipment according to claim 11, characterized in that: The fume treatment equipment also includes a feeding tank (10) filled with inert material (7); the feeding tank (10) is connected to the fume inlet (1) through a feeding mechanism (5); the inert material (7) in the feeding tank (10) is sequentially mixed with the metal fume to be purified and then injected into the reaction chamber (8); the feeding tank (10) is provided with a pressure replenishing pipe (11) connected to the clean airflow or the purified metal fume; preferably, the feeding tank (10) is an integral structure or a replaceable structure; preferably, when the feeding tank (10) is an integral structure, the feeding tank (10) is provided with an openable feeding port.

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