System and method for quality-divided treatment of dedusting ash in large flue of sintering machine based on air bellow flue gas temperature shunting

Abstract

The invention relates to the technical field of ferrous metallurgy sintering flue gas purification and resource recovery, and discloses a sintering machine large flue dedusting ash quality-divided treatment system and method based on air bellow flue gas temperature shunting. The system comprises a sintering machine body, a plurality of large flue bellows, a temperature monitoring device, a flow dividing control unit, a pneumatic flow dividing valve, a low-temperature flue gas collecting branch pipe, a high-temperature flue gas collecting branch pipe, a low-temperature dust remover, a high-temperature dust remover, a collecting flue and a desulfurization and denitrification system. The method has the advantages that the safe internal circulation of clean dust is realized, the iron material cost is saved, the dust enriched with pollutants is converted into artificial rich ore which can be sold, waste is turned into wealth, benefits are created, the internal treatment cost is thoroughly eliminated, vicious cycle accumulation of chlorine salt and heavy metal in an ironmaking system is fundamentally blocked, and the economic benefit is increased. And the overall smelting environment and technical and economic indexes are improved.

Description

Technical Field

[0001] This invention relates to the field of sintering flue gas purification and resource recovery technology in iron and steel metallurgy, specifically to a dust removal and ash separation treatment system and method for the main flue gas duct of a sintering machine based on flue gas temperature diversion in a wind box. Background Technology

[0002] In the sintering production process of the iron and steel metallurgy industry, the sintering machine is the core equipment. During its operation, it generates a large amount of dust-laden flue gas. This flue gas needs to be treated for dust removal after being collected through the main flue to meet environmental emission requirements.

[0003] Current processes typically involve mixing the flue gas from all the air boxes before it enters a main dust collector for centralized dust removal. However, the sintering process exhibits significant temperature and composition gradients along the length of the sintering trolley. The middle air box corresponds to the sintering combustion zone, where the flue gas temperature is high (often exceeding 150°C), carrying a large amount of pollutants such as alkali metals (K, Na), heavy metals (Zn, Pb), and chlorides that volatilize due to the high temperature. In contrast, the flue gas temperature in the head and tail air boxes is lower (usually below 150°C), resulting in relatively lower pollutant content. The existing mixed treatment mode results in complex composition of the collected flue dust. Among them, the dust collected by the final stage of the electrostatic precipitator is often classified as hazardous waste due to its high enrichment of harmful components, requiring expensive external disposal. Meanwhile, the dust from the front stage of the electrostatic precipitator is barely returned to the batching. This not only wastes valuable resources such as iron and carbon and incurs huge disposal costs, but more seriously, returning the dust containing chloride salts and heavy metals to the batching will cause these harmful elements to circulate and accumulate in the sintering-blast furnace system, deteriorating the quality of sinter and pellets, restricting the smooth operation and longevity of the blast furnace, and increasing the cost of subsequent environmental treatment. It is difficult to meet the current requirements of efficient and environmentally friendly production. Therefore, a sintering machine flue dust separation treatment system and method based on the temperature diversion of the flue gas in the blast box is proposed to solve the above-mentioned problems. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a sintering machine flue dust separation and treatment system and method based on flue gas temperature diversion in a bellows. This system features safe internal circulation of clean dust, saves iron material costs, transforms pollutant-rich dust into marketable "artificial rich ore," turning waste into treasure, generating revenue, and completely eliminating internal disposal costs. It fundamentally blocks the vicious cycle of chloride and heavy metal accumulation in the ironmaking system, improves the overall smelting environment and technical and economic indicators, and solves the problem of complex composition of collected flue dust caused by existing mixed treatment methods. Specifically, electrostatic precipitation... Dust collected by the final stage electric field of the dust collector is often classified as hazardous waste due to its high concentration of harmful components, requiring expensive external disposal. Dust from the preceding electric field is barely returned to the batching process. This not only wastes valuable resources such as iron and carbon and incurs huge disposal costs, but more seriously, returning some of the dust containing chloride salts and heavy metals to the batching process causes these harmful elements to accumulate in the sintering-blast furnace system, deteriorating the quality of sinter and pellets, restricting the smooth operation and longevity of the blast furnace, and increasing the cost of subsequent environmental treatment. This makes it difficult to meet the current requirements for efficient and environmentally friendly production.

[0005] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: A dust removal and ash separation treatment system for a sintering machine large flue based on flue gas temperature diversion, including a sintering machine trolley, several large flue boxes, a temperature monitoring device, a diversion control unit, a pneumatic diversion valve, a low-temperature flue gas collecting branch pipe, a high-temperature flue gas collecting branch pipe, a low-temperature dust collector, a high-temperature dust collector, a collection flue, as well as a desulfurization and denitrification system, a feeding system, and a cooling system; Several large flue boxes are respectively installed below the sintering machine trolley. Each large flue box is independently equipped with a temperature monitoring device and a pneumatic diversion valve at its outlet. The diversion control unit is electrically connected to all temperature monitoring devices and pneumatic diversion valves. It is used to independently control the corresponding pneumatic diversion valve to switch to connect with the low-temperature flue gas collection branch or the high-temperature flue gas collection branch according to the real-time flue gas temperature signal of each large flue box. The outlet of the pneumatic diversion valve is selectively connected to the low-temperature flue gas collection branch or the high-temperature flue gas collection branch. The inlet of the low-temperature flue gas collecting branch pipe is connected to the outlet of each corresponding pneumatic diverter valve, and the outlet of the low-temperature flue gas collecting branch pipe is connected to the inlet of the low-temperature dust collector; the inlet of the high-temperature flue gas collecting branch pipe is connected to the outlet of each corresponding pneumatic diverter valve, and the outlet of the high-temperature flue gas collecting branch pipe is connected to the inlet of the high-temperature dust collector. The clean gas outlets of the low-temperature dust collector and the high-temperature dust collector are both connected to the inlet of the combined flue, and the outlet of the combined flue is connected to the inlet of the desulfurization and denitrification system.

[0006] Based on the above technical solution, the present invention can be further improved as follows.

[0007] Furthermore, the preset temperature shunting threshold of the shunting control unit is 140-160℃.

[0008] Furthermore, a first ash silo is provided below the low-temperature dust collector. The first ash silo is used to collect first dust with low heavy metal and low chloride salt content, and the first ash silo is connected to the sintering batching system through a conveying device.

[0009] Furthermore, the high-temperature dust collector is an electrostatic precipitator, and a second ash bin is provided below the high-temperature dust collector. The second ash bin is used to collect second dust containing dust collected by the final stage electric field. The dust collected by the final stage electric field of the high-temperature dust collector, which is rich in heavy metals and chloride salts, is used to be sold as a man-made rich mineral product.

[0010] Furthermore, the temperature monitoring device is a wear-resistant thermocouple sensor, and the shunt control unit is a PLC controller.

[0011] Furthermore, a dust removal and ash separation treatment system and method for sintering machine flue gas based on flue gas temperature diversion includes the following steps: S1: The temperature data of the flue gas discharged from the large flue box is collected in real time by a temperature monitoring device installed at the outlet of the large flue box. S2: The diversion control unit receives temperature data transmitted by each temperature monitoring device, judges the flue gas temperature of the large flue box, and independently controls the switching path of the pneumatic diversion valve at the outlet of the corresponding large flue box. S3: The flue gas collected through the low-temperature flue gas collecting branch pipe enters the low-temperature dust collector for dust removal treatment, and the first dust is collected; the flue gas collected through the high-temperature flue gas collecting branch pipe enters the high-temperature dust collector for dust removal treatment, and the second dust is collected. S4: The two clean flue gases after dust removal in step S3 are combined in the combined flue and then sent to the desulfurization and denitrification system for deep purification. S5: The first dust collected in step S3 is transported to the sintering batching process for recycling; the portion of the second dust collected in step S3 that is enriched with heavy metals and chloride salts is sold as an artificial rich mineral product.

[0012] Furthermore, the preset threshold in step S2 is 150°C. When the flue gas temperature of a certain large flue box is ≤150°C, the corresponding pneumatic diversion valve is controlled to guide the flue gas into the low-temperature flue gas collection branch pipe; when the flue gas temperature is >150°C, the corresponding pneumatic diversion valve is controlled to guide the flue gas into the high-temperature flue gas collection branch pipe.

[0013] Furthermore, in step S3, the contents of heavy metal elements such as potassium, sodium, zinc, and lead, as well as chloride ions in the first dust collector are lower than the contents of the corresponding elements in the second dust collector from the final stage electric field of the high-temperature dust collector, so the second dust collector generated by the final stage electric field of the high-temperature dust collector is preferentially separated and collected.

[0014] Furthermore, the dust enriched with heavy metals and chlorides described in step S5 is used as an alternative raw material in the non-ferrous metallurgical industry.

[0015] The beneficial effects of this invention are: 1) The sintering machine flue dust removal and ash separation treatment system and method based on flue gas temperature diversion in the wind box has the advantages of precise source separation and maximum benefits: independent diversion is carried out at each wind box outlet, realizing the accurate classification and collection of flue gas with different properties, and can completely separate the dust with highly enriched harmful elements from the circulation system, turning it from "disposal cost" into "sales revenue", with significant economic benefits.

[0016] 2) The dust removal and ash treatment system and method for the sintering machine flue based on the temperature diversion of the flue gas in the wind box has the advantages of completely breaking the harmful cycle and improving the process: it fundamentally eliminates the return of dust rich in chloride salts and heavy metals to the batching, greatly improves the quality of sintered ore, creates conditions for the stable operation and extended service life of the blast furnace, and allows for the use of a wider range of low-priced raw materials, with huge potential benefits.

[0017] 3) The sintering machine flue dust removal and ash separation treatment system and method based on flue gas temperature diversion has the advantages of strong technical implementation, convenient modification: the system is modular and can be modified on the basis of existing flue and dust removal systems without interfering with the main process, and the investment payback period is short. Attached Figure Description

[0018] Figure 1 This is a structural system diagram of the present invention; Figure 2 This is a flowchart of the structural method of the present invention.

[0019] In the diagram: 1. Main flue gas duct; 2. Temperature monitoring device; 3. Diversion control unit; 4. Pneumatic diversion valve; 5. Low-temperature flue gas collection branch pipe; 6. High-temperature flue gas collection branch pipe; 7. Low-temperature dust collector; 8. High-temperature dust collector; 9. Main flue; 10. Desulfurization and denitrification system; 71. First ash silo; 81. Second ash silo. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] In the embodiments, by Figure 1 The present invention provides a dust removal and ash separation system for a sintering machine flue based on flue gas temperature diversion. The system includes a sintering machine trolley, several large flue boxes 1, a temperature monitoring device 2, a diversion control unit 3, a pneumatic diversion valve 4, a low-temperature flue gas collecting branch pipe 5, a high-temperature flue gas collecting branch pipe 6, a low-temperature dust collector 7, a high-temperature dust collector 8, a collection flue 9, and a desulfurization and denitrification system 10. Several large flue boxes 1 are correspondingly set under the sintering machine trolley. Each large flue box 1 is independently equipped with a temperature monitoring device 2 and a pneumatic diversion valve 4 at its outlet. The diversion control unit 3 is electrically connected to all temperature monitoring devices 2 and pneumatic diversion valves 4. It is used to independently control the corresponding pneumatic diversion valve 4 to switch to connect with the low temperature flue gas collection branch pipe 5 or the high temperature flue gas collection branch pipe 6 according to the real-time flue gas temperature signal of each large flue box 1. The outlet of the pneumatic diversion valve 4 is selectively connected to the low temperature flue gas collection branch pipe 5 or the high temperature flue gas collection branch pipe 6. The inlet of the low-temperature flue gas collecting branch pipe 5 is connected to the outlet of each corresponding pneumatic diverter valve 4, and the outlet of the low-temperature flue gas collecting branch pipe 5 is connected to the inlet of the low-temperature dust collector 7; the inlet of the high-temperature flue gas collecting branch pipe 6 is connected to the outlet of each corresponding pneumatic diverter valve 4, and the outlet of the high-temperature flue gas collecting branch pipe 6 is connected to the inlet of the high-temperature dust collector 8. The clean gas outlets of both the low-temperature dust collector 7 and the high-temperature dust collector 8 are connected to the inlet of the combined flue duct 9, and the outlet of the combined flue duct 9 is connected to the inlet of the desulfurization and denitrification system 10.

[0022] This application achieves precise diversion of flue gas by independently installing temperature monitoring devices 2 and pneumatic diversion valves 4 at the outlets of each flue gas duct 1, in conjunction with diversion control units 3. Then, the flue gas is connected to low-temperature dust collectors 7 and high-temperature dust collectors 8 through low-temperature flue gas collection branch pipes 5 and 6 respectively to complete the separate dust removal. Finally, the flue gas is collected through the main flue duct 9 and leads to the desulfurization and denitrification system 10, thus constructing a complete system of "diversion-separate dust removal-unified purification". This system effectively separates flue gas at different temperatures from the source, provides core equipment support for dust removal and ash separation treatment, ensures the accuracy and feasibility of separation treatment, and guarantees that the final emission of flue gas meets the standards.

[0023] In this embodiment, a main pipe can also be connected below the large flue box 1. The bottom end of the main pipe is equipped with two connecting pipes through a pneumatic diversion valve 4. The two connecting pipes are respectively connected to the low-temperature flue gas pipe and the high-temperature flue gas pipe. The low-temperature flue gas pipe and the high-temperature flue gas pipe are respectively connected to the low-temperature flue gas collecting branch pipe 5 and the high-temperature flue gas collecting branch pipe 6. Thus, all the low-temperature flue gas generated by the large flue box 1 will be collected in the low-temperature flue gas pipe and then discharged through the low-temperature flue gas collecting branch pipe 5; all the high-temperature flue gas generated by the large flue box 1 will be collected in the high-temperature flue gas pipe and then discharged through the high-temperature flue gas collecting branch pipe 6, thereby improving the overall flue gas discharge efficiency.

[0024] The application also includes a sintering batching system for adding material to the inside of the sintering machine trolley, and a cooling system for cooling the entire system. The outlet of the desulfurization and denitrification system 10 is connected to the chimney through the main exhaust fan, so that the exhaust gas from the desulfurization and denitrification system 10 can be discharged through the chimney.

[0025] In this embodiment, the preset temperature shunting threshold of the shunting control unit 3 is 140-160℃, preferably 150℃; In the diversion control unit 3, 150°C is preset as the temperature diversion threshold. This threshold is determined based on the correspondence between flue gas temperature and pollutant content during the sintering process. When the diversion control unit 3 receives the real-time flue gas temperature signal from each temperature monitoring device 2, it compares the temperature value corresponding to each signal with the 150°C threshold. Based on the comparison result, it independently controls the opening of the corresponding pneumatic diversion valve 4 to achieve accurate introduction of flue gas into the low-temperature flue gas collection branch pipe 5 or the high-temperature flue gas collection branch pipe 6. When the flue gas temperature of a certain large flue box 1 is ≤150℃, the corresponding pneumatic diversion valve 4 is controlled to guide the flue gas into the low temperature flue gas collecting branch pipe 5; when the flue gas temperature is >150℃, the corresponding pneumatic diversion valve 4 is controlled to guide the flue gas into the high temperature flue gas collecting branch pipe 6.

[0026] In this embodiment, after the low-temperature dust collector 7 removes dust from the low-temperature flue gas transported from the low-temperature flue gas collection branch pipe 5, the separated low-heavy metal and low-chloride dust falls into the first ash bin 71 below under the action of gravity for storage. The first ash bin 71 is connected to the sintering batching system through a preset conveying device. The stored dust is stably transported to the sintering batching system through the conveying device to participate in the subsequent sintering batching process. Meanwhile, during the dust removal process, the low-temperature dust collector 7 can also collect the first dust in the first collection box through the double-layer ash discharge valve, and then transport it to the first ash silo 71 for storage through the bucket elevator.

[0027] The high-temperature dust collector 8 is an electrostatic precipitator. After receiving the high-temperature flue gas from the high-temperature flue gas collection branch pipe 6, it removes dust from the flue gas through the action of an electric field. The dust separated by each stage of the electric field falls into the second ash bin 81 below. The dust collected by the final stage of the electric field is highly enriched with heavy metals and chloride salts, so it is stored separately in the second ash bin 81. After being packaged, it is sold as a "man-made rich mineral" product. Meanwhile, during the dust removal process, the high-temperature dust collector 8 can also collect the second dust in the second collection box through the double-layer ash discharge valve, and then transport it to the second ash silo 81 for storage through the bucket elevator. The discharge of the second dust is controlled by the star-shaped ash discharge valve, and finally the second dust is transported out by truck.

[0028] The temperature monitoring device 2 uses a wear-resistant thermocouple sensor, which is fixedly installed at the outlet of the large flue box 1, so that its sensing end is in direct contact with the flue gas, and can withstand the high temperature environment of sintering flue gas and dust wear, ensuring the stability and service life of temperature detection. The diversion control unit 3 uses a PLC controller, which electrically connects the signal output terminals of all wear-resistant thermocouple sensors to the signal input terminals of the PLC controller, and electrically connects the control terminals of all pneumatic diversion valves 4 to the signal output terminals of the PLC controller. By writing control programs in the PLC controller, the automated operation of temperature signal reception, judgment and pneumatic diversion valve switching control is realized.

[0029] Additionally, this application can add a main exhaust fan inside the low-temperature flue gas collecting branch pipe 5 and the high-temperature flue gas collecting branch pipe 6, which can accelerate the conveying of flue gas from the low-temperature flue gas collecting branch pipe 5 and the high-temperature flue gas collecting branch pipe 6 to the main flue duct 9. Furthermore, a silencer can be added inside the low-temperature flue gas collecting branch pipe 5 and the high-temperature flue gas collecting branch pipe 6 to reduce the noise generated during the conveying process.

[0030] Example 2, by Figure 2 A dust removal and ash separation system and method for sintering machine flue gas based on flue gas temperature diversion is provided, including the following steps: S1: The temperature data of the flue gas discharged from the large flue box 1 is collected in real time by the temperature monitoring device 2 installed at the outlet of the large flue box 1. S2: The diversion control unit 3 receives the temperature data transmitted by each temperature monitoring device 2, judges the flue gas temperature of the large flue box 1, and independently controls the pneumatic diversion valve 4 at the outlet of the corresponding large flue box 1 to switch the path. S3: The flue gas collected by the low-temperature flue gas collecting branch pipe 5 enters the low-temperature dust collector 7 for dust removal treatment, and the first dust is collected; the flue gas collected by the high-temperature flue gas collecting branch pipe 6 enters the high-temperature dust collector 8 for dust removal treatment, and the second dust is collected. S4: The two clean flue gases after dust removal in step S3 are combined in the converging flue duct 9 and then transported to the desulfurization and denitrification system 10 for deep purification treatment. S5: The first dust collected in step S3 is transported to the sintering batching process for recycling; the portion of the second dust collected in step S3 that is enriched with heavy metals and chloride salts is sold as an artificial rich mineral product.

[0031] This method fully utilizes the diversion function of temperature monitoring device 2, diversion control unit 3, and pneumatic diversion valve 4. It achieves separate dust removal for flue gases of different properties by using low-temperature flue gas collecting branch pipe 5, high-temperature flue gas collecting branch pipe 6, low-temperature dust collector 7, and high-temperature dust collector 8. The combined flue duct 9 and desulfurization and denitrification system 10 ensure that the flue gas meets emission standards. Ultimately, it realizes the recycling of the first dust removal ash and the resource-based sale of the enriched part of the second dust removal ash, completely breaking the cycle accumulation of heavy metals and chloride salts in the ironmaking system. It has significant environmental protection value, process improvement value, and economic benefits.

[0032] In this embodiment, a temperature threshold range of 140-160℃ is preset in the diversion control unit 3. This range is determined based on the actual distribution law of flue gas temperature in different air boxes during the sintering process. In actual application, the optimal threshold can be selected within this range according to factors such as the type of sintering raw materials and the adjustment of sintering conditions. Preferably, 150℃ is used as the standard preset threshold. The diversion control unit 3 judges the flue gas temperature of each flue air box 1 according to the selected threshold, and then controls the pneumatic diversion valve 4 to complete the flue gas diversion.

[0033] The first dust collected by the low-temperature dust collector 7 has significantly lower content of heavy metals such as potassium, sodium, zinc, and lead, as well as chloride ions, than the corresponding component content of the second dust collected by the final stage electric field of the high-temperature dust collector 8. Based on this component difference, the first dust meets the quality requirements for recycling sintering materials. The second dust collected by the final stage electric field of the high-temperature dust collector 8, due to its enrichment of heavy metals and chloride salts, has the resource value to be sold as an "artificial rich mine".

[0034] The dust collected by the final electric field of the high-temperature dust collector, which is rich in heavy metals and chloride salts, is collected separately, packaged, and then sold as a substitute raw material to enterprises in the non-ferrous metallurgical industry for use as a supplementary raw material in the non-ferrous metallurgical production process.

[0035] Example 3: This example combines Example 1 and Example 2, taking two 460m² sintering machines in a steel plant as an example.

[0036] Original process conditions: Of the dust collected by the original large flue electrostatic precipitator, only about 6,000 tons / year of dust collected by the final stage electric field, which has serious excessive levels of heavy metals and chlorides, needs to be handed over to an external unit for disposal as hazardous waste, with a disposal cost of about 400 yuan / ton.

[0037] The annual disposal cost is: 6000 tons × 400 yuan / ton = 2.4 million yuan. The recycling of the remaining dust leads to the accumulation of harmful elements within the system.

[0038] After applying this invention: The dust collected by the high-temperature flue gas electrostatic precipitator in the final stage of the system achieves targeted and efficient enrichment of harmful elements, transforming "hazardous waste" into valuable "man-made rich minerals." This enriched dust volume is approximately 6,000 tons / year, which can be sold as a product to non-ferrous metallurgical enterprises at a price of 400 yuan / ton.

[0039] Annual sales revenue is: 6,000 tons × 400 yuan / ton = 2.4 million yuan.

[0040] Meanwhile, the low-temperature dust collected by the system of this invention has a low content of harmful elements and can be safely and harmlessly recycled, fundamentally cutting off the internal circulation path of harmful elements.

[0041] Economic benefit calculation: • Savings in original disposal costs: 2.4 million yuan / year. (No longer payable) • New sales revenue from enriched ash: RMB 2.4 million / year.

[0042] The direct comprehensive economic benefits generated are: cost savings + sales revenue = 240 + 240 = 4.8 million yuan / year.

[0043] Furthermore, the environmental benefits and potential process benefits brought about by this invention are even more significant: 1. Completely break the cycle: avoids the return of tens of thousands of tons of dust containing chloride salts and heavy metals to the batching, greatly improves the quality of sinter and pellets, and is conducive to the long-term stable operation of the blast furnace.

[0044] 2. Expanding the range of ore blending: It reduces the restrictions on harmful elements in raw materials, making it possible to use more low-priced ores, which can further reduce ironmaking costs.

[0045] 3. Green and low-carbon: It realizes the high-value resource utilization of solid waste, which is in line with the development direction of circular economy and green manufacturing.

[0046] In summary, this invention not only directly generates significant economic benefits, but its indirect benefits and optimization of the overall production system also hold strategic value. After deducting system investment and operating costs, the investment payback period is short, and its application prospects are broad.

[0047] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0048] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A dust removal and ash separation system for sintering machine flue gas based on flue gas temperature diversion, characterized in that: It includes a sintering machine trolley, several large flue boxes (1), a temperature monitoring device (2), a diversion control unit (3), a pneumatic diversion valve (4), a low-temperature flue gas collection branch pipe (5), a high-temperature flue gas collection branch pipe (6), a low-temperature dust collector (7), a high-temperature dust collector (8), a collection flue (9), and a desulfurization and denitrification system (10). Several large flue boxes (1) are respectively set below the sintering machine trolley. Each large flue box (1) is independently equipped with a temperature monitoring device (2) and a pneumatic diversion valve (4) at its outlet. The diversion control unit (3) is electrically connected to all temperature monitoring devices (2) and pneumatic diversion valves (4) and is used to independently control the corresponding pneumatic diversion valve (4) to switch to connect with the low temperature flue gas collection branch pipe (5) or the high temperature flue gas collection branch pipe (6) according to the real-time flue gas temperature signal of each large flue box (1). The outlet of the pneumatic diversion valve (4) is selectively connected to the low temperature flue gas collection branch pipe (5) or the high temperature flue gas collection branch pipe (6). The inlet of the low-temperature flue gas collecting branch pipe (5) is connected to the outlet of each corresponding pneumatic diverter valve (4), and the outlet of the low-temperature flue gas collecting branch pipe (5) is connected to the inlet of the low-temperature dust collector (7); the inlet of the high-temperature flue gas collecting branch pipe (6) is connected to the outlet of each corresponding pneumatic diverter valve (4), and the outlet of the high-temperature flue gas collecting branch pipe (6) is connected to the inlet of the high-temperature dust collector (8). The clean gas outlet of the low-temperature dust collector (7) and the clean gas outlet of the high-temperature dust collector (8) are both connected to the inlet of the combined flue (9), and the outlet of the combined flue (9) is connected to the inlet of the desulfurization and denitrification system (10).

2. The sintering machine flue dust removal and ash separation treatment system based on flue gas temperature diversion in a wind tunnel according to claim 1, characterized in that: The preset temperature shunting threshold of the shunting control unit (3) is 140-160℃.

3. The sintering machine flue dust removal and ash separation treatment system based on flue gas temperature diversion in a wind tunnel according to claim 1, characterized in that: The low-temperature dust collector (7) is provided with a first ash bin (71) below it. The first ash bin (71) is used to collect the first dust with low heavy metal and low chloride salt content. The first ash bin (71) is connected to the sintering batching system through a conveying device.

4. The sintering machine flue dust removal and ash separation treatment system based on flue gas temperature diversion in a wind tunnel according to claim 3, characterized in that: The high-temperature dust collector (8) is an electrostatic precipitator. A second ash bin (81) is provided below the high-temperature dust collector (8). The second ash bin (81) is used to collect second dust containing dust collected by the final stage electric field. The dust collected by the final stage electric field of the high-temperature dust collector (8), which is rich in heavy metals and chloride salts, is used to sell as artificial rich mineral products.

5. The sintering machine flue gas dust removal and ash separation treatment system based on flue gas temperature diversion in a wind tunnel according to claim 1, characterized in that: The temperature monitoring device (2) is a wear-resistant thermocouple sensor, and the shunt control unit (3) is a PLC controller.

6. A method for dust removal and ash separation treatment of a sintering machine's main flue based on flue gas temperature diversion according to any one of claims 1-5, characterized in that: Includes the following steps: S1: The temperature data of the flue gas discharged from the large flue box (1) is collected in real time by the temperature monitoring device (2) installed at the outlet of the large flue box (1); S2: The diversion control unit (3) receives the temperature data transmitted by each temperature monitoring device (2), judges the flue gas temperature of the large flue box (1), and independently controls the pneumatic diversion valve (4) at the outlet of the corresponding large flue box (1) to switch the path. S3: The flue gas collected by the low-temperature flue gas collection branch pipe (5) enters the low-temperature dust collector (7) for dust removal treatment and the first dust is collected. The flue gas collected by the high-temperature flue gas collection branch pipe (6) enters the high-temperature dust collector (8) for dust removal treatment and the second dust is collected. S4: The two clean flue gases after dust removal in step S3 are combined in the combined flue (9) and then transported to the desulfurization and denitrification system (10) for deep purification. S5: The first dust collected in step S3 is transported to the sintering batching process for recycling; the portion of the second dust collected in step S3 that is enriched with heavy metals and chloride salts is sold as an artificial rich mineral product.

7. The method for dust removal and ash separation treatment of sintering machine flue gas based on flue gas temperature diversion according to claim 6, characterized in that: In step S3, the contents of potassium, sodium, zinc, lead and chloride ions in the first dust are lower than the contents of the corresponding elements in the second dust from the final electric field of the high-temperature dust collector (8).

8. The method for dust removal and ash separation treatment of sintering machine flue gas based on flue gas temperature diversion according to claim 7, characterized in that: The dust collected from heavy metals and chloride salts, which is sold externally in step S5, is used as an alternative raw material in the non-ferrous metallurgical industry.

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