Flue gas and solid waste collaborative treatment system and method

Abstract

The present invention is a flue gas and solid waste coordinated treatment system and method, which includes a grinding device, a first dust removal device, a preheating and desorption device, a rotary kiln and a preheating device, wherein the outlet of the grinding device is connected to the flue gas duct of the electric furnace, the inlet of the first dust removal device is connected to the outlet of the grinding device and the electric furnace, the dust ash inlet of the preheating and desorption device is connected to the ash discharge port of the first dust removal device, the rotary kiln is connected to the desorption gas interface and hot air return port of the preheating and desorption device, and the outlet of the preheating device and the dust ash outlet of the preheating and desorption device are respectively connected to the rotary kiln. The present invention can use the coke and / or charcoal produced by activated carbon desulfurization and denitrification to completely remove dioxins in the flue gas of the electric furnace. The removed dioxins will not be resynthesized to cause secondary pollution. At the same time, they can react with solid waste materials and dust ash to recover valuable elements in the solid waste materials and dust ash, thereby realizing the coordinated resource utilization of multiple wastes.

Description

Technical Field

[0001] The present invention relates to the technical field of flue gas purification and solid waste treatment, and further to a system and method for the coordinated treatment of flue gas and solid waste, and in particular to a system and method for removing dioxins from waste active substances generated by activated carbon desulfurization and denitrification, and for the coordinated treatment of carbon- and dioxin-containing dust ash with iron- and zinc-containing dust sludge. Background Art

[0002] In the steel industry, electric furnace steelmaking and sintering processes are the primary sources of dioxin emissions. The mechanism of dioxin formation during electric furnace smelting is as follows: during the initial melting phase / preheating of scrap steel, organic substances such as oils, grease, and paint react with heat to form "precursors," which then form dioxins through organic chemical reactions. Dioxins are completely decomposed during high-temperature periods, but are regenerated during cooling. Specifically, when the ambient temperature reaches 280°C to 450°C, hydrocarbons and organic chlorides react to form dioxins. When the ambient temperature exceeds 980°C, dioxins completely decompose, and when the ambient temperature drops to 470°C, dioxins are regenerated.

[0003] At present, the dioxin removal treatment of flue gas produced by electric furnaces has not been carried out. The dioxin content is 5-12ngTEQ / Nm 3 , which is higher than the dioxin emission limit of sintering flue gas (0.5ngTEQ / N m 3 According to statistics, dioxin emissions are approximately 10.2 kg TEQ per year, of which 4.59 kg TEQ is emitted from steel smelting, accounting for 45% of the total, and dioxin emissions from the electric furnace process account for approximately 50% of this.

[0004] In addition, activated carbon desulfurization and denitrification is one of the common desulfurization and denitrification processes in sintering and coking processes. Due to the wear and pulverization of activated carbon during the circulation process, a large amount of broken carbon and carbon powder are discharged from the system, which greatly increases the operating cost of the system and causes waste of activated carbon. The steel industry will produce dust and mud containing iron and / or zinc elements to varying degrees in various processes, some of which will be reused. The reuse cycle will lead to zinc enrichment, which will lead to system deterioration. Therefore, dezincification or takeaway treatment is necessary.

[0005] The most mature process for removing dioxins from flue gas from electric furnaces is to use activated carbon powder injection for removal. However, the problem that comes with this is that the activated carbon that adsorbs dioxins is transferred to the dust ash, and whether it is a hazardous waste requires testing and determination. In addition, the introduction of dioxins and activated carbon will make the dust ash from the electric furnace unusable. If the conventional heating reuse method is used, as mentioned above, it will cause the dioxins to desorb and escape, causing secondary pollution.

[0006] Therefore, the inventors, relying on their many years of experience and practice in related industries, have proposed a flue gas and solid waste coordinated treatment system and method to overcome the shortcomings of the existing technology. Summary of the Invention

[0007] The object of the present invention is to provide a flue gas and solid waste coordinated treatment system and method, which uses waste active substances generated by pulverized activated carbon desulfurization and denitrification to remove dioxins from flue gas, realizes the resource utilization of dust ash containing dioxins, and recovers valuable elements such as Zn and Fe. In the treatment process, dioxins can be completely decomposed and removed without transfer, avoiding the secondary generation of dioxins after cooling; at the same time, other zinc- and iron-containing dust sludge can also be coordinated to treat, realizing the coordinated resource utilization of dust ash.

[0008] The purpose of the present invention can be achieved by adopting the following scheme:

[0009] The present invention provides a flue gas and solid waste coordinated treatment system, comprising:

[0010] A grinding device for grinding waste active substances generated by activated carbon desulfurization and denitrification, and for adsorbing dioxins in the flue gas of the electric furnace through the ground waste active substances, wherein the outlet of the grinding device is connected to the flue gas duct of the electric furnace;

[0011] a first dust removal device for separating dust and the waste active material adsorbing the dioxins from the flue gas, wherein the inlet of the first dust removal device is connected to the outlet of the grinding device and the electric furnace respectively;

[0012] a preheating and desorption device for desorbing the dioxins adsorbed on the waste active material and preheating the dust, the preheating and desorption device having at least a dust removal inlet, a dust removal outlet, a desorption gas interface, a hot air inlet, and a hot air return port, the dust removal inlet being connected to the dust discharge port of the first dust removal device;

[0013] A rotary kiln, which is used to perform high-temperature decomposition of the desorbed dioxins and treat the dust sludge, and the rotary kiln is respectively connected to the desorption gas interface and the hot air return port of the preheating desorption device;

[0014] A preheating device is used to preheat the added solid waste material. The outlet of the preheating device and the dust removal ash outlet of the preheating and desorption device are respectively connected to the rotary kiln, so that the solid waste material and the dust removal ash react in the rotary kiln to generate recyclable materials, and the hot air generated during the recovery process is cooled and allowed to enter the preheating and desorption device through the hot air inlet of the preheating and desorption device; at least part of the flue gas generated by the rotary kiln enters the preheating and desorption device as a desorption carrier gas.

[0015] In a preferred embodiment of the present invention, the waste active material is waste active crushed coke and / or crushed char.

[0016] In a preferred embodiment of the present invention, the solid waste material is dust and mud containing zinc and / or iron, and waste activated coke and / or carbon produced by activated carbon desulfurization and denitrification;

[0017] The recyclable material is the iron-containing material and / or zinc-containing material obtained after the high-temperature reduction reaction of the solid waste material and / or dust ash.

[0018] In a preferred embodiment of the present invention, the flue gas and solid waste coordinated treatment system includes a material bin for storing the waste active substances generated by activated carbon desulfurization and denitrification. The material bin has at least a first discharge port and a second discharge port, and the first discharge port and the second discharge port are respectively connected to the inlet of the grinding device and the feed port of the preheating device.

[0019] In a preferred embodiment of the present invention, the inlet of the first dust removal device is connected to the flue gas outlet of the electric furnace through a pre-dust removal flue, and the outlet of the grinding device is connected to the pre-dust removal flue through an activated carbon output pipeline, and the ground waste active material adsorbs the dioxins in the pre-dust removal flue.

[0020] In a preferred embodiment of the present invention, an injection device is provided on the activated carbon output pipeline to inject the ground waste active material into the flue before dust removal.

[0021] In a preferred embodiment of the present invention, the rotary kiln has at least a kiln head and a kiln tail, and the rotary kiln is tilted downward from the kiln tail to the kiln head. A burner is provided in the rotary kiln near the kiln head, and the desorption gas interface and the hot air return port of the preheating and desorption device are connected to the kiln head. A feeding cavity is provided between the kiln tail and the discharge port of the preheating device, and the dust removal ash outlet of the preheating and desorption device is connected to the feeding cavity.

[0022] In a preferred embodiment of the present invention, the hot air return port of the preheating desorption device is connected to the kiln head position through a hot air return pipeline, a second fan is provided on the hot air return pipeline, and the desorption gas interface of the preheating desorption device is connected to the hot air return pipeline through a desorption gas pipeline, and a third fan is provided on the desorption gas pipeline.

[0023] In a preferred embodiment of the present invention, an inner cavity is formed inside the preheating desorption device, and the dust removal ash inlet, the dust removal ash outlet, the desorption gas interface, the hot air inlet and the hot air return port are respectively connected to the inner cavity, and a first airtight valve is provided on the dust removal inlet or on the pipeline connected to the dust removal inlet, and a second airtight valve is provided on the dust removal outlet or on the pipeline connected to the dust removal outlet.

[0024] In a preferred embodiment of the present invention, a plurality of dust removal ash passage pipes are provided inside the preheating and desorption device, and the ends of the plurality of dust removal ash passage pipes are respectively connected to the dust removal ash inlet and the dust removal ash outlet, and the dust removal ash and the desorbed dioxins pass through the plurality of dust removal ash passage pipes;

[0025] A plurality of baffles are provided inside the preheating and desorption device and between the hot air inlet and the hot air return port. The plurality of baffles are used to increase the flow of the hot air in the preheating and desorption device. The hot air flows in opposite directions to the dust ash. The hot air flows through the outside of the dust ash passage pipeline to heat the dust ash in the dust ash passage pipeline, thereby achieving thermal desorption of dioxins in the dust ash.

[0026] In a preferred embodiment of the present invention, sealing plates for isolating the dust from hot air are respectively provided at the upper and lower parts of the dust removal ash passing pipeline, and the dust removal ash passing pipeline passes through the sealing plates.

[0027] In a preferred embodiment of the present invention, the plurality of baffles are arranged at intervals from the hot air inlet and the hot air return port, one end of the plurality of baffles is fixed on the inner wall of the preheating desorption device, and an overflow gap is left between the other opposite end of the plurality of baffles and the inner wall of the preheating desorption device, and the overflow gaps corresponding to two adjacent baffles are staggered.

[0028] In a preferred embodiment of the present invention, the interior of the preheating and desorption device adopts a shell-and-tube heat exchange structure or a partition wall heat exchange structure.

[0029] In a preferred embodiment of the present invention, the flue gas and solid waste coordinated treatment system further includes a second dust removal device, which is used to recover the zinc-containing material obtained after the solid waste material and / or dust removal ash undergoes a reduction reaction, the inlet of the second dust removal device is connected to the preheating device through a flue gas pipeline, and the outlet of the second dust removal device is connected to a second chimney through a clean flue gas pipeline, and a fourth fan is provided on the clean flue gas pipeline;

[0030] A desorption carrier gas inlet is provided at the dust removal ash outlet of the preheating desorption device, and the desorption carrier gas inlet is connected to the clean flue gas pipeline through a desorption carrier gas pipeline.

[0031] In a preferred embodiment of the present invention, the flue gas and solid waste coordinated treatment system also includes a cooling device, which is used to cool the iron-containing material obtained after the solid waste material and / or dust ash undergoes a reduction reaction. The cooling device has at least a cold air inlet, a material outlet, a material inlet and a hot air outlet. The material inlet is connected to the rotary kiln, and the hot air outlet is connected to the hot air inlet of the preheating desorption device.

[0032] In a preferred embodiment of the present invention, a fifth fan is provided at the cold air inlet of the cooling device or on a second air duct connected to the cold air inlet.

[0033] The present invention provides a flue gas and solid waste collaborative treatment method, which uses the above-mentioned flue gas and solid waste collaborative treatment system to collaboratively treat the flue gas generated by the electric furnace and the added solid waste materials. The method includes the following steps:

[0034] Step S1: Grinding the waste active substances generated by activated carbon desulfurization and denitrification into powder;

[0035] Step S2: using the ground spent active material to adsorb dioxins in the flue gas of the electric furnace;

[0036] Step S3: separating dust and the waste active material adsorbing the dioxins from the flue gas of the electric furnace;

[0037] Step S4: desorbing the dioxins adsorbed on the waste active material and preheating the dust removal ash;

[0038] Step S5: decomposing the desorbed dioxins at high temperature in a rotary kiln;

[0039] Step S6: preheating the added solid waste material, and subjecting the preheated solid waste material and the desorbed dust to a high-temperature reduction reaction in the rotary kiln;

[0040] Step S7: Processing the solid waste and recyclable materials generated by high-temperature reduction of dust ash.

[0041] In a preferred embodiment of the present invention, in step S1, the waste active material produced by desulfurization and denitrification of activated carbon with a particle size of less than 2 mm is ground into a particle size greater than or equal to 1000 m 2 / g of carbon powder, wherein the particle size of the carbon powder is less than or equal to 250 meshes.

[0042] In a preferred embodiment of the present invention, in step S4, the temperature is raised to 450° C. to 600° C. to decompose or desorb dioxins.

[0043] In a preferred embodiment of the present invention, a burner is provided at the kiln head of the rotary kiln. The temperature of the high-temperature flue gas generated by the burner is greater than 1100° C., so that dioxins are fully decomposed.

[0044] In a preferred embodiment of the present invention, in step S6, at a temperature of 900° C. to 1200° C., the zinc element in the solid waste and / or the dust ash is reduced and volatilized by the activated carbon to form zinc vapor.

[0045] And / or, the iron elements in the solid waste and dust ash are reduced by the activated carbon to form iron-rich substances.

[0046] In a preferred embodiment of the present invention, the rotary kiln cools and discharges the iron-rich material in step S7 and generates hot air for desorption of dioxins in step S4 and for combustion air in step S5.

[0047] In a preferred embodiment of the present invention, a small portion of the hot flue gas generated in step S6 is returned to the desorption device after being cooled and dust-removed, and is used as a hot carrier gas to carry away the desorbed dioxin gas;

[0048] In step S7, the coarse zinc powder product formed by condensation of zinc vapor is collected by the second dust collector.

[0049] As described above, the characteristics and advantages of the flue gas and solid waste coordinated treatment system and method of the present invention are: the waste active material generated by the desulfurization and denitrification of the ground activated carbon adsorbs dioxins in the flue gas of the electric furnace, the dust and the waste active material adsorbed with dioxins are separated from the flue gas by the first dust removal device, the dust removal ash inlet of the preheating and desorption device is connected to the ash discharge port of the first dust removal device, the waste active material adsorbed with dioxins and the dust are transported to the preheating and desorption device, and the dioxins adsorbed on the waste active material are removed by the preheating and desorption device. Desorption is carried out, and the desorbed dioxins enter the rotary kiln and are fully decomposed in a high-temperature environment. There are no precursors such as hydrocarbons and organic chlorides in the decomposed flue gas. Even if the flue gas is cooled, dioxins will not be synthesized again, thereby achieving complete and harmless removal of dioxins in the flue gas of the electric furnace. In addition, the added solid waste materials and the dust ash obtained after dioxin desorption undergo high-temperature reduction reaction in the rotary kiln to generate recyclable materials, thereby realizing the synergistic resource utilization of by-products and solid waste materials produced by flue gas purification. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] The following drawings are only intended to illustrate and explain the present invention, and are not intended to limit the scope of the present invention.

[0051] in:

[0052] Figure 1 : It is a structural diagram of the flue gas and solid waste coordinated treatment system of the present invention.

[0053] Figure 2 : It is a structural schematic diagram of the preheating and desorption device in the flue gas and solid waste coordinated treatment system of the present invention.

[0054] Figure 3 : It is a structural schematic diagram of the cooling device in the flue gas and solid waste coordinated treatment system of the present invention.

[0055] Figure 4 : This is a flow chart of the flue gas and solid waste collaborative treatment method of the present invention.

[0056] The accompanying drawings in the present invention are:

[0057] 1. Electric furnace; 2. Grinding device; 3. First dust removal device; 4. Preheating and desorption device; 401. Inner cavity; 402. Dust ash passage; 403. Baffle; 404. Dust ash inlet; 405. Dust ash outlet; 406. Desorption gas interface; 407. Hot air inlet; 408. Hot air return port; 5. Preheating device; 6. Feeding cavity; 7. Rotary kiln; 701. Kiln tail; 702. Kiln head; 703. Burner; 8. Cooling device; 801. Cold air inlet; 802. Material outlet; 803. Hot air outlet; 804. Material inlet; 9. , the fifth fan; 10. The second fan; 11. The second dust removal device; 12. The fourth fan; 13. The second chimney; 14. The third fan; 15. The material bin; 16. The flue before dust removal; 17. The activated carbon output pipeline; 18. The fixed carbon batching pipeline; 19. The first fan; 20. The first chimney; 21. The dust removal ash conveying pipeline; 22. The first airtight valve; 23. The second airtight valve; 24. The desorption carrier gas pipeline; 25. The desorption gas pipeline; 26. The flue gas pipeline; 27. The second air duct; 28. The first air duct; 29. ​​The hot air return pipeline; 30. The clean flue gas pipeline. DETAILED DESCRIPTION

[0058] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described with reference to the accompanying drawings.

[0059] Implementation Method 1

[0060] like Figures 1 to 3As shown, the present invention provides a flue gas and solid waste coordinated treatment system, which includes a grinding device 2, a first dust removal device 3, a preheating and desorption device 4, a rotary kiln 7 and a preheating device 5. The grinding device 2 is used to grind the waste active material generated by activated carbon desulfurization and denitrification, and adsorb dioxins in the flue gas of the electric furnace through the ground waste active material. The outlet of the grinding device 2 is connected to the flue gas duct of the electric furnace 1 (that is, the pre-dust removal flue 16); the first dust removal device 3 is used to separate dust and waste active material adsorbed with dioxins from the flue gas, and the inlet of the first dust removal device 3 is connected to the outlet of the grinding device 2 and the electric furnace 1 respectively; the preheating and desorption device 4 is used to desorb dioxins adsorbed on the waste active material and preheat the dust, and the preheating and desorption device 4 has at least a dust removal inlet 404, dust removal ash outlet 405, desorption gas interface 406, hot air inlet 407 and hot air return port 408, the dust removal ash inlet 404 is connected to the ash discharge port of the first dust removal device 3; the rotary kiln 7 is used to decompose the desorbed dioxins at high temperature and treat the dust mud, and the rotary kiln 7 is respectively connected to the desorption gas interface 406 and the hot air return port 408 of the preheating desorption device 4; the preheating device 5 is used to preheat the added solid waste material (zinc-containing, iron-containing dust mud, activated carbon), and the outlet of the preheating device 5 and the dust removal ash outlet 405 of the preheating desorption device 4 are respectively connected to the rotary kiln 7, so that the solid waste material and dust removal ash react in the rotary kiln 7 and generate recyclable materials. During the recovery process, cooling generates hot air, and the hot air enters the preheating desorption device 4 through the hot air inlet 407 of the preheating desorption device 4. The hot flue gas generated by burner 703 in rotary kiln 7 preheats preheating device 5. After cooling, the hot flue gas enters second dust removal device 11 to recover zinc. The resulting clean flue gas is discharged through second chimney 13. Part of the clean flue gas is sent to preheating and desorption device 4 for use as a desorption carrier gas. Hot air generated by cooling device 8 is sent to preheating and desorption device 4 for desorption of dioxins and preheating of dust ash.

[0061] In the present invention, waste active matter generated by desulfurization and denitrification of ground activated carbon adsorbs toxic substances in the flue gas of the electric furnace. Dust and waste active matter adsorbed with dioxins are separated from the flue gas by the first dust removal device 3. The dust removal ash inlet 404 of the preheating and desorption device 4 is connected to the ash discharge port of the first dust removal device 3. The waste active matter adsorbed with dioxins and dust are transported to the preheating and desorption device 4. The preheating and desorption device 4 desorbs the dioxins adsorbed on the waste active matter. The desorbed toxic dioxins enter the rotary kiln 7 and are fully decomposed in a high-temperature environment. The decomposed flue gas is free of precursors such as hydrocarbons and organic chlorides. Even after the flue gas is cooled, dioxins will not be resynthesized, thereby achieving complete and harmless removal of dioxins in the flue gas of the electric furnace. In addition, the added solid waste and the dust removal ash obtained after dioxin desorption undergo a high-temperature reduction reaction in the rotary kiln to generate recyclable materials, thereby achieving synergistic resource utilization of by-products and solid waste generated by flue gas purification.

[0062] Furthermore, the grinding device 2 may be, but is not limited to, a grinder that can grind the activated carbon desulfurization and denitrification products with a diameter less than 2 mm removed by the vibrating screen into products with a specific surface area greater than or equal to 1000 m 2 / g of carbon powder, the particle size of the carbon powder is less than or equal to 250 mesh.

[0063] Furthermore, the waste active material is waste active coke and / or char.

[0064] Furthermore, the added solid waste materials include dust and mud containing zinc and / or iron, and waste activated coke and / or charcoal produced by activated carbon desulfurization and denitrification. The recyclable materials include zinc-containing and / or iron-containing materials obtained by high-temperature reduction reaction of solid waste materials and / or dust ash.

[0065] In an optional embodiment of the present invention, Figure 1 As shown, the flue gas and solid waste coordinated treatment system includes a material bin 15, which is used to store waste active substances generated by activated carbon desulfurization and denitrification. A feed port is provided at the top of the material bin 15, and at least a first discharge port and a second discharge port are provided at the bottom of the material bin 15. The first discharge port is connected to the inlet of the grinding device 2, and is used to add waste active substances generated by activated carbon desulfurization and denitrification to the grinding device 2; the second discharge port is connected to the feed port of the preheating device 5 through a fixed carbon feed pipeline 18, and is used to add activated carbon into the preheating device 5.

[0066] In an optional embodiment of the present invention, Figure 1As shown, the inlet of the first dust removal device 3 is connected to the flue gas outlet of the electric furnace 1 through the pre-dust removal flue 16, and the outlet of the grinding device 2 is connected to the pre-dust removal flue 16 through the activated carbon output pipeline 17. The ground activated carbon enters the pre-dust removal flue 16 through the activated carbon output pipeline 17, and the ground waste active material adsorbs dioxins in the pre-dust removal flue 16.

[0067] In this embodiment, an injection device (not shown) is provided on the activated carbon output pipeline 17, through which the ground waste active material can be injected into the pre-dust removal flue 16. The injection amount of the waste active material can be, but is not limited to, 0 to 1200 mg / Nm 3 Of course, it can also be adjusted according to the actual dioxin emission concentration. The injection amount of waste active substances can be greater than 1200mg / Nm 3 , ensuring the thorough adsorption of dioxins, and the amount of waste active substances injected will not affect the resource utilization effect of the present invention.

[0068] Further, such as Figure 1 As shown, the outlet of the first dust removal device 3 is connected to the first chimney 20, and a first fan 19 is provided between the outlet of the first dust removal device 3 and the first chimney 20 to discharge the clean flue gas in the first dust removal device 3 to the outside.

[0069] In an optional embodiment of the present invention, Figure 1 As shown, the rotary kiln 7 has at least a kiln head 702 and a kiln tail 701. The rotary kiln 7 is tilted downward from the kiln tail 701 to the kiln head 702. A burner 703 is provided in the rotary kiln 7 near the kiln head 702, and the desorption gas interface 406 and the hot air return port 408 of the preheating and desorption device 4 are respectively connected to the kiln head 702. A feeding cavity 6 is provided between the kiln tail 701 and the discharge port of the preheating device 5, and the dust removal ash outlet 405 of the preheating and desorption device 4 is connected to the feeding cavity 6.

[0070] Further, if Figure 1 As shown, the preheating device 5 can be but is not limited to a rotary kiln preheater. The rotary kiln preheater is a vertical structure. A plurality of material inlets are provided on the top of the rotary kiln preheater, and solid waste materials and activated carbon can be added into the rotary kiln preheater respectively. A discharge port is provided at the bottom of the rotary kiln preheater.

[0071] Furthermore, the rotary kiln 7 is inclined downward by 2.5% to 8% from the kiln tail 701 to the kiln head 702 .

[0072] Further, such as Figure 1As shown, the hot air return port 408 of the preheating and desorption device 4 is connected to the kiln head 702 via a hot air return pipeline 29. A second fan 10 is provided on the hot air return pipeline 29. The desorption gas interface 406 of the preheating and desorption device 4 is connected to the hot air return pipeline 29 via a desorption gas pipeline 25. A third fan 14 is provided on the desorption gas pipeline 25. The second fan 10 is a hot air fan, and the third fan 14 is a carrier gas fan. The hot air from the preheating and desorption device 4 can be transported by the second and third fans 10, 14 to the burner 703 located at the kiln head 702 of the rotary kiln 7 for use as combustion-supporting air for the burner 703.

[0073] In an optional embodiment of the present invention, Figure 1 、 Figure 2 As shown, the preheating and desorption device 4 is arranged vertically, and an inner cavity 401 is formed inside the preheating and desorption device 4. The dust inlet 404, the dust outlet 405, the desorption gas interface 406, the hot air inlet 407 and the hot air return port 408 are respectively connected to the inner cavity 401. The dust inlet 404 and the desorption gas interface 406 are respectively located at the top of the preheating and desorption device 4, and the dust outlet 405 is located at the bottom of the preheating and desorption device 4. The hot air inlet 407 and the hot air return port 408 are both located on the side wall of the preheating and desorption device 4, and the height of the hot air inlet 407 is less than the height of the hot air return port 408, so that the hot air passing through the preheating and desorption device 4 and the dust ash (containing waste active substances adsorbed with dioxins) are in relative flow directions, so as to desorb dioxins and preheat the dust ash.

[0074] Further, such as Figure 1 As shown, a first airtight valve 22 is provided on the dust removal ash inlet 404 or the pipeline connected to the dust removal ash inlet 404 (dust removal ash conveying pipeline 21), and a second airtight valve 23 is provided on the dust removal ash outlet 405 or the pipeline connected to the dust removal ash outlet 405, which can prevent the preheating and desorption device 4 from cross-gasing with upstream and / or downstream equipment, and at the same time prevent the desorbed dioxins from overflowing into the upstream and / or downstream equipment, and maintain a slightly negative pressure environment in the preheating and desorption device 4 to ensure work safety.

[0075] Specifically, such as Figure 2As shown, a plurality of dust removal ash passing pipes 402 are vertically arranged inside the preheating desorption device 4, one end of the plurality of dust removal ash passing pipes 402 are connected to the dust removal ash inlet 404 and the desorption gas interface 406, and the other end of the plurality of dust removal ash passing pipes 402 are connected to the dust removal ash outlet 405, and the dust removal ash and the desorbed dioxins pass through the plurality of dust removal ash passing pipes 402; a plurality of baffles 403 are arranged inside the preheating desorption device 4 and between the hot air inlet 407 and the hot air return port 408. The baffles 403 are plate-shaped structures arranged in the horizontal direction, and the plurality of baffles 403 are formed by the hot air inlet 407 and the hot air return port 408. The air inlet 407 and the hot air return port 408 are spaced apart. One end of the multiple baffles 403 is fixed to the inner wall of the preheating and desorption device 4. A flow gap is left between the other opposite ends of the baffles 403 and the inner wall of the desorption device 4. The flow gaps corresponding to adjacent baffles 403 are staggered. The multiple baffles 403 increase the flow of hot air within the preheating and desorption device 4. The hot air and dust ash flow in opposite directions, passing through the outside of the dust ash passage duct 402 to heat the dust ash within the dust ash passage duct 402 and thermally desorb dioxins adsorbed by the dust ash. During operation, the dust ash flows through the tube side, while the hot air flows through the shell side, preventing direct contact between the dust ash and the hot air.

[0076] Further, such as Figure 2 As shown, the dust removal ash passes through the pipeline and is respectively provided with sealing plates for isolating the dust removal ash from the hot air. The sealing plates are respectively located in the preheating and desorption device 4 and close to its top and bottom. The dust removal ash passes through the pipeline and passes through the sealing plates.

[0077] In the present invention, the interior of the preheating and desorption device may adopt a shell-and-tube heat exchange structure or a partition-wall heat exchange structure.

[0078] In an optional embodiment of the present invention, Figure 1 As shown, the flue gas and solid waste coordinated treatment system also includes a second dust removal device 11, which is used to recover the zinc-containing substance obtained after the solid waste material and / or dust ash undergoes a reduction reaction. The inlet of the second dust removal device 11 is connected to the preheating device 5 through a flue gas pipeline 26, and the outlet of the second dust removal device 11 is connected to the second chimney 13 through a clean flue gas pipeline 30, and a fourth fan 12 is provided on the clean flue gas pipeline 30; a desorption carrier gas inlet is also provided at the dust ash outlet 405 of the preheating desorption device 4, and the desorption carrier gas inlet is connected to the clean flue gas pipeline 30 through a desorption carrier gas pipeline 24.

[0079] Furthermore, the second dust removal device 11 may be, but is not limited to, a bag dust collector.

[0080] In an optional embodiment of the present invention, Figure 1As shown, the flue gas and solid waste coordinated treatment system also includes a cooling device 8, which is used to recover the iron-containing substances obtained after the solid waste material and / or dust removal ash undergoes a reduction reaction. The cooling device 8 has at least a cold air inlet 801, a material outlet 802, a hot air outlet 803 and a material inlet 804. The material inlet 804 is connected to the rotary kiln 7, and the hot air outlet 803 is connected to the hot air inlet 407 of the preheating and desorption device 4.

[0081] Further, such as Figure 1 As shown, a fifth fan 9 is provided at the cold air inlet 801 of the cooling device 8 or on the second air duct 27 connected to the cold air inlet 801. The fifth fan 9 is a cold air fan that delivers external cold air into the cooling device 8, thereby cooling the high-temperature iron-containing material, and the cooled iron-containing material is discharged and collected.

[0082] During the actual engineering process of the plant, if there is no waste activated carbon for desulfurization and denitrification in the plant, activated carbon powder can be purchased from outside to be used for adsorption of dioxins, and coking coal can be purchased from outside to be used for carbonization of solid waste materials.

[0083] The characteristics and advantages of the flue gas and solid waste coordinated treatment system of the present invention are:

[0084] 1. The flue gas and solid waste coordinated treatment system uses the waste active material generated by ground activated carbon desulfurization and denitrification to adsorb dioxins in the flue gas of the electric furnace. The first dust removal device 3 separates dust and the waste active material adsorbed with dioxins from the flue gas, and transports the dust ash (containing the waste active material adsorbed with dioxins) to the preheating and desorption device 4. The preheating and desorption device 4 desorbs the dioxins adsorbed on the waste active material. The desorbed dioxins enter the rotary kiln 7 and are fully decomposed in a high-temperature environment. The decomposed flue gas does not contain precursors such as hydrocarbons and organic chlorides. Even after the flue gas is cooled, dioxins will not be resynthesized, thereby achieving complete and harmless removal of dioxins in the flue gas of the electric furnace. In addition, the added solid waste and the dust ash obtained after dioxin desorption undergo a high-temperature reduction reaction in the rotary kiln to generate recyclable materials, thereby achieving coordinated resource utilization of by-products and solid waste generated by flue gas purification.

[0085] 2. In the flue gas and solid waste coordinated treatment system, a burner 703 is provided at the kiln head 702 of the rotary kiln 7, and the kiln tail 701 is connected to the preheating and desorption device 4 and the preheating device 5 through the feeding cavity 6. The hot air in the cooling device 8 can enter the preheating and desorption device 4 and complete the desorption of dioxins before being used as secondary air for the rotary kiln 7. The dioxins directly enter the high-temperature section of the rotary kiln 7 for incineration and decomposition, which can ensure the full decomposition of the dioxins without the need for a slow heating process, avoid the production of a large number of dioxin intermediates or precursors, and avoid the re-synthesis of dioxins after cooling.

[0086] 3. In the flue gas and solid waste coordinated treatment system, the hot air between the hot air inlet 407 and the hot air return port 408 and the desorption carrier gas transported through the desorption carrier gas pipeline 24 are respectively sent to different flow channels. The desorption carrier gas flow rate is small and the flow velocity is low. The hot air does not contact the dust removal ash, thereby significantly reducing the dust content in the desorption carrier gas and the hot air, avoiding problems such as pipe and fan wear and pipe blockage.

[0087] Implementation Method 2

[0088] like Figure 4 As shown, the present invention provides a flue gas and solid waste collaborative treatment method, which uses the above-mentioned flue gas and solid waste collaborative treatment system to collaboratively treat the flue gas generated by the electric furnace 1 and the added solid waste materials. The flue gas and solid waste collaborative treatment method includes the following steps:

[0089] Step S1: Grinding the waste active substances generated by activated carbon desulfurization and denitrification into powder;

[0090] Step S2: using the ground spent active material to adsorb dioxins in the flue gas of the electric furnace;

[0091] Step S3: separating dust and waste active substances adsorbing the dioxins from the flue gas of the electric furnace;

[0092] Step S4: desorbing the dioxins adsorbed on the waste active material and preheating the dust removal ash;

[0093] Step S5: decomposing the desorbed dioxins at high temperature in the rotary kiln 7;

[0094] Step S6: preheating the added solid waste material, and subjecting the preheated solid waste material and the desorbed dust to a high-temperature reduction reaction in the rotary kiln 7;

[0095] Step S7: Processing the solid waste and recyclable materials generated by high-temperature reduction of dust ash.

[0096] In an optional embodiment of the present invention, in step S1, the waste active substances produced by desulfurization and denitrification with a particle size of less than 2 mm are ground into particles with a specific surface area greater than or equal to 1000 m 2 / g of carbon powder, the particle size of the carbon powder is less than or equal to 250 mesh.

[0097] In an optional embodiment of the present invention, in step S4, the temperature is increased to 450°C to 600°C to decompose or desorb dioxins.

[0098] In an optional embodiment of the present invention, in step S5, a burner 703 is provided at the kiln head 702 of the rotary kiln 7. The temperature of the high-temperature flue gas generated by the burner 703 is greater than 1100° C., so that dioxins are fully decomposed.

[0099] In an optional embodiment of the present invention, in step S6, zinc in the solid waste and / or dust ash is reduced and volatilized by activated carbon at a temperature of 900° C. to 1200° C. to form zinc vapor. Iron in the solid waste and / or dust ash is also reduced by activated carbon to form iron-rich material.

[0100] In an optional embodiment of the present invention, the hot flue gas generated by combustion in step S6 enters preheating device 5, where it is used to preheat the solid waste and cool the hot flue gas. Zinc is recovered from the cooled flue gas, and a small amount of the resulting clean flue gas is then used as a desorption carrier gas and fed into preheating and desorption device 4 to remove the desorbed dioxins. The hot air generated in step S7 first enters preheating and desorption device 4 to heat the dust and desorb dioxins, and is then fed into kiln head 702 of rotary kiln 7 as combustion air.

[0101] Due to wear and tear, the activated carbon desulfurization and denitrification fragments in the plant are pulverized. To maintain the air permeability of the system, a vibrating screen is used to screen out the activated carbon fragments with a diameter of less than 2mm and burn them directly as fuel. Due to the high cost of activated carbon and its low value when burned directly as fuel, in order to maximize its value, the activated carbon powder in the present invention can be used to remove dioxins from electric furnace flue gas. The specific process flow of the present invention is as follows:

[0102] The coke and / or carbon fragments produced by desulfurization and denitrification of activated carbon can be transported by car and loaded into the material bin 15. The partially desulfurized and denitrified carbon fragments in the material bin 15 are fed into the grinding device 2 to grind the activated carbon desulfurization and denitrification carbon fragments with a particle size of less than 2 mm into particles with a specific surface area (BET) ≥ 1000 m 2 / g, activated carbon powder with a particle size of 250 mesh, and then the activated carbon powder is sprayed into the flue 16 before dust removal. The activated carbon powder adsorbs dioxins in the flue gas discharged from the electric furnace 1 in the flue 16 before dust removal. Then, the flue gas carries the activated carbon powder adsorbed with dioxins into the first dust removal device 3, and the activated carbon powder adsorbed with dioxins is captured by the filter bag of the first dust removal device 3. After cleaning, it falls into the ash hopper at the bottom of the first dust removal device 3, thereby achieving the removal of dioxins in the flue gas of the electric furnace; the clean flue gas at the outlet of the first dust removal device 3 is discharged to the outside through the first chimney 20.

[0103] In addition, due to the high total iron content in the electric furnace dust ash, it is generally considered to be reused. However, after being mixed with activated carbon containing dioxins, the carbon powder is not easy to remove, and heating and re-smelting will cause the adsorbed dioxins to desorb and re-enter the atmospheric environment, causing secondary pollution. Therefore, it is necessary to treat the electric furnace dust ash harmlessly and as a resource. After the present invention performs the above-mentioned treatment of dioxins in the flue gas of the electric furnace, the dust ash (containing activated carbon powder) in the bottom ash hopper of the first dust removal device 3 can be transported to the preheating desorption device 4 through the dust ash conveying pipeline 21. The dust ash slowly flows from top to bottom through the entire pipe process of the dust ash through the pipeline 402, and the hot air in the preheating desorption device 4 flows from bottom to top through the interior of the preheating desorption device 4 in a deflected manner. The hot air will pass the dust ash through the pipeline 402. The dust is preheated and heated to 450°C to 600°C, decomposing and fully desorbing the dioxins adsorbed on the dust. Simultaneously, a desorption carrier gas line 24 slowly introduces hot carrier gas from the bottom of the preheating and desorption device 4, blowing away the dioxins desorbed and desorbed within the preheating and desorption device 4. The entrained dioxins are then fed into the hot air return line 29 via the desorption gas line 25 and the third fan 14. The dioxins are then fed into the rotary kiln 7 by the second fan 10 for high-temperature decomposition. The first and second airtight valves 22 and 23 prevent the escape of dioxins, while the suction effect of the third fan 14 maintains a slightly negative pressure within the preheating and desorption device 4 to facilitate dioxin removal. The dust ash, preheated and de-dioxined within the preheating and desorption device 4, is discharged into the rotary kiln 7 via the feeding chamber 6.

[0104] The solid waste materials (other zinc- and iron-containing dust and mud, such as blast furnace gas ash, converter ash, iron oxide scale, steel rolling dust and mud, electric furnace ash, etc.) can be mixed with the waste active materials produced by the activated carbon desulfurization and denitrification transported to the preheating device 5 by the fixed carbon feed pipeline 18, and are countercurrently contacted with the hot flue gas of 600°C to 900°C from the rotary kiln 7 for preheating and temperature increase. After that, the solid waste materials (including activated carbon) are discharged into the rotary kiln 7. Since the rotary kiln 7 is tilted along its axial direction and rotates slowly along its circumference, the materials in the rotary kiln 7 (i.e., solid waste, activated carbon, and dust) roll and turn along the circumference of the rotary kiln 7, and at the same time slide along the axial direction of the rotary kiln 7 from the kiln tail 701 to the kiln head 702. After being heated by the burner 703 located near the kiln head 702, a high-temperature section (temperature of 900°C to 1200°C) is formed in the rotary kiln 7. When the materials slide to the high-temperature section of the rotary kiln, the zinc in the solid waste and dust is reduced by the activated carbon powder and volatilized to form zinc vapor, which is discharged along the hot flue gas. The zinc vapor is condensed in the second dust removal device 11 and oxidized into secondary zinc oxide due to the low temperature in the second dust removal device 11. The secondary zinc oxide is collected and processed in the second dust removal device 11 to obtain a coarse zinc powder product. The hot flue gas after treatment and dezincification passes through the clean flue gas pipeline 30 and the fourth fan 12 in turn. Most of it is discharged through the second chimney 13. A small part of the hot flue gas is sent to the bottom of the preheating and desorption device 4 and used as a desorption hot carrier gas to bring dioxins into the rotary kiln 7 for desorption. Decomposition; solid waste and iron oxides in dust ash react with activated carbon to generate iron-rich slag, which is discharged from a position near the kiln head 702 into the cooling device 8. In the cooling device 8, the high-temperature iron-rich slag contacts the cooling air sent in through the second air duct 27. The iron-rich slag is discharged after cooling (it can be used for sintering and blast furnace batching). The hot air generated by the high-temperature iron-rich slag during the cooling process is introduced into the hot air inlet 407 of the preheating and desorption device 4 by the first air duct 28, and enters the preheating and desorption device 4 for the desorption of dioxins. Afterwards, the hot air and the desorption carrier The dioxins carried in the flue gas are delivered by the second blower 10 to a position near the kiln head 702 in the rotary kiln 7. The hot air can serve as high-temperature combustion-supporting air (i.e., secondary air) to the incoming fuel gas, and the temperature of the heated rotary kiln 7 is greater than 1100°C. The generated hot flue gas stays in this high-temperature area for more than 2 seconds, which ensures that the dioxins contained in the flue gas are completely decomposed. Since the hot flue gas after decomposition does not contain precursors such as hydrocarbons and organic chlorides, dioxins will not be synthesized even after the temperature of the hot flue gas drops, thereby achieving the complete removal and harmlessness of dioxins in the flue gas of the electric furnace.

[0105] The characteristics and advantages of the flue gas and solid waste collaborative treatment method of the present invention are:

[0106] 1. This flue gas and solid waste coordinated treatment method can achieve high-value utilization of waste activated carbon generated by the activated carbon desulfurization and denitrification system (rather than directly using it as fuel). The high activity of the pulverized desulfurization and denitrification activated carbon can be used to remove dioxins from the flue gas of the electric furnace, saving the high cost of purchasing activated carbon powder. At the same time, the crushed activated carbon powder from desulfurization and denitrification can be directly used as the ingredient of the rotary kiln 7 and used as a reducing agent.

[0107] 2. This method of coordinated treatment of flue gas and solid waste can realize the resource utilization of electric furnace dust containing dioxins, recover valuable elements such as zinc and iron, and completely decompose and remove dioxins during the treatment process without transfer, thereby avoiding the secondary synthesis of dioxins after cooling. At the same time, it can also coordinate the treatment of zinc- and iron-containing dust and mud, and waste active substances (i.e., solid waste substances) generated by desulfurization and denitrification, thereby realizing the coordinated resource utilization of dust ash.

[0108] 3. In this flue gas and solid waste coordinated treatment method, the dust removal ash adsorbed with dioxins and the zinc and iron-containing dust sludge are separated for preheating treatment, which reduces the treatment difficulty, improves the treatment efficiency, and realizes the harmless disposal and resource utilization of the dust removal ash containing dioxins.

[0109] 4. In the flue gas and solid waste coordinated treatment method, the clean flue gas of the rotary kiln 7 can be used as the desorption carrier gas. Since the oxygen content in the clean flue gas is low (can be as low as 1%), it is used together with the hot air in the preheating desorption device 4 as the secondary air of the rotary kiln 7, thereby lengthening the flame length of the burner 703 in the rotary kiln 7 and improving the heating uniformity of the rotary kiln 7. At the same time, it also has the effect of low-nitrogen combustion, reducing the generation of pollutants (such as NOx).

[0110] Two comparative examples are provided below to illustrate the effects of the flue gas and solid waste coordinated treatment system and method of the present invention.

[0111] Example:

[0112] A steel company has a 120t electric furnace. The dioxin content in the primary flue gas of the furnace is 10ngTEQ / Nm 3 , need to be removed. The company currently has 360m 2 A sintering machine is used to purify the flue gas from the machine head by using the activated carbon desulfurization and denitrification process. 300 kg / h of waste activated carbon with a particle size of less than 2 mm is produced. The waste activated carbon is packed in tons of bags, transported and loaded into the material bin 15 of the present invention. A part of the activated carbon is discharged into the grinding device 2, and the waste activated carbon with a particle size of less than 2 mm is ground into activated carbon powder with a size of less than 200 mesh. The activated carbon powder is sprayed into the flue 16 before the dust removal through metering feeding. The injection amount of the activated carbon powder is 0 to 200 mg / Nm 3The amount of activated carbon powder used is about 50kg / h. The activated carbon powder in the flue 16 before dust removal absorbs and removes dioxins in the flue gas of the electric furnace, and then the activated carbon powder adsorbed with dioxins enters the first dust removal device 13. The first dust removal device 13 uses a coated filter material or an ultra-fine surface filter material to make the filtration wind speed less than 0.8m / min, so that dust and activated carbon powder can be removed. After backblowing and cleaning, the activated carbon powder adsorbed with dioxins and dust ash fall into the ash hopper.

[0113] The electric furnace dust (including activated carbon powder) in the ash hopper is pneumatically conveyed to the preheating and desorption device 4. The electric furnace dust (including activated carbon powder) with dioxins adsorbed in the preheating and desorption device 4 flows through the pipe process. Its flow direction is countercurrently heat exchanged with the 450°C to 800°C hot air in the preheating and desorption device 4 and outside the dust ash passage pipe 402. The dioxins are desorbed and partially decomposed, and are carried away by the desorption carrier gas entering from the bottom of the preheating and desorption device 4 and sent to the rotary kiln 7.

[0114] The company's blast furnace gas ash, converter secondary ash, and other medium- and high-zinc sludge (greater than 1%) are mixed with waste activated carbon (particle size less than 2 mm) from the aforementioned material bin 15, adjusting the total activated carbon mass to at least 35% of the sludge. After mixing, the mixture is then fed into the preheating device 5. According to Table 1 (ingredients), the principle of mixing is that the sum of the carbon in the sludge and the added desulfurization and denitrification waste carbon reaches 15% to 30% of the total.

[0115] Dust type TFe FeO <![CDATA[SiO2]]> CaO MgO <![CDATA[Al2O3]]> C Zn Blast furnace gas ash 55.20 8.00 8.21 6.67 1.12 4.49 17 3.49 Converter secondary ash ～51 - 2～4 ～9 ～3 - 3～5 2～4 Electric furnace ash 45.23 8.31 2.06 2.92 1.38 0.56 4.12 2.61

[0116] Table 1

[0117] In the preheating device 5 , the high-temperature flue gas from the rotary kiln 7 can reach 650°C to 1000°C. The mixture of dust sludge and waste activated carbon can be preheated to 650°C to 800°C in the preheating device 5 , and then enters the feeding cavity 6 , and is then mixed with the dust ash after dioxin desorption in the preheating desorption device 4 and enters the rotary kiln 7 .

[0118] The rotary kiln 7 is tilted 4% to 8% from the kiln tail 701 to the kiln head 702. During the kiln's rotation (0 to 1 r / min), the material inside the kiln 7 slides toward the kiln head 702. A burner 703 is located near the kiln head 702. The incoming fuel gas and hot air from the preheating and desorption device 4 combust in contact, raising the temperature of the kiln 7. The low oxygen content in the desorbed gas mixed with the hot air facilitates the elongation of the combustion flame, ensuring uniform heating of the kiln 7. Dioxins carried by the hot air and desorbed gas are decomposed in the combustion flame. A high-temperature zone of 1100°C to 1200°C forms near the ignition of the fuel gas. Under these conditions, unburned dioxins can be further decomposed, achieving complete dioxin removal. Due to the complete combustion, dioxin precursors are also decomposed, preventing dioxin re-synthesis after the hot flue gas cools.

[0119] Inside the rotary kiln 7, the material residence time is controlled to be at least 1.5 hours. The dust and sludge material is gradually heated to a temperature above 900°C. The zinc in the dust and sludge is reduced by the activated carbon powder, precipitating zinc vapor and volatilizing. As the temperature continues to rise, the activated carbon powder also reduces metal oxides such as iron, producing iron-rich slag. The zinc oxide content in the iron-rich slag is less than 1%, which can be discharged into the cooling device 8. Within the cooling device 8, the iron-rich slag contacts the incoming cooling air, cooling it. The iron-rich slag product can then be discharged and reused in ironmaking and steelmaking processes, achieving iron recovery. Simultaneously, the cooling air absorbs heat within the cooling device 8, raising its temperature to 450°C to 800°C before being delivered to the preheating desorption device 4 for dioxin desorption.

[0120] Zinc vapor, along with the high-temperature flue gas flow from the rotary kiln 7, passes through the feeding chamber 6 and preheating device 5, where its temperature drops to below 240°C. The zinc vapor then enters the second dust removal device 11, where it is reoxidized into solid zinc oxide. This is then collected in the flue and bags of the second dust removal device 11, resulting in the secondary zinc oxide powder product. A small portion of the purified flue gas from the second dust removal device 11 is fed into the preheating and desorption device 4, serving as a desorption carrier gas to carry away dioxins. The majority of the flue gas is discharged through the second chimney 13.

[0121] Comparative Example:

[0122] A steel conglomerate used activated carbon to remove dioxin from a 120t electric furnace flue gas. Because the furnace raw materials contained a lot of oil and plastic, the dioxin concentration fluctuated greatly. After dioxin removal, the resulting dioxin-containing electric furnace dust was tested for hazardous waste. The maximum dioxin concentration reached 4μgTEQ / kg, while the normal concentration was 0.38μgTEQ / kg. Dioxin-removed electric furnace ash is mixed with other dust, sludge, and charcoal powder and fed into the rotary kiln's vertical preheater via a conveyor belt. The preheater's feed temperature is 230°C, and the discharge temperature is 600°C to 800°C. As the mixture descends and heats up, dioxins adsorbed on the activated carbon decompose and volatilize. After the dioxins decompose, hydrocarbons and organic chlorides react at temperatures between 280°C and 450°C to reconstitute dioxins. These volatilized and reconstituted dioxins enter the flue gas treatment system along with the rotary kiln flue gas. Therefore, the addition of a dedicated dioxin removal device is necessary to achieve dioxin removal. As can be seen from the comparative example, the dioxins in the electric furnace flue gas are not rendered harmless; they are simply transferred to the rotary kiln flue gas, requiring secondary removal.

[0123] The above description is only an illustrative embodiment of the present invention and is not intended to limit the scope of the present invention. Any equivalent changes and modifications made by those skilled in the art without departing from the concept and principle of the present invention shall fall within the scope of protection of the present invention.

Claims

1. A flue gas and solid waste collaborative treatment system, characterized in that: include: A grinding device for grinding waste active substances generated by activated carbon desulfurization and denitrification, and for adsorbing dioxins in the flue gas of the electric furnace through the ground waste active substances, wherein the outlet of the grinding device is connected to the flue gas duct of the electric furnace; a first dust removal device for separating dust and the waste active material adsorbing the dioxins from the flue gas, wherein the inlet of the first dust removal device is connected to the outlet of the grinding device and the electric furnace respectively; a preheating and desorption device for desorbing the dioxins adsorbed on the waste active material and preheating the dust, the preheating and desorption device having at least a dust removal inlet, a dust removal outlet, a desorption gas interface, a hot air inlet, and a hot air return port, the dust removal inlet being connected to the dust discharge port of the first dust removal device; A rotary kiln, which is used to perform high-temperature decomposition of the desorbed dioxins and treat the dust sludge, and the rotary kiln is respectively connected to the desorption gas interface and the hot air return port of the preheating desorption device; A preheating device for preheating added solid waste, wherein the outlet of the preheating device and the dust removal ash outlet of the preheating and desorption device are respectively connected to the rotary kiln, so that the solid waste and the dust removal ash react in the rotary kiln to generate recyclable materials, and the hot air generated during the recovery process is cooled and enters the preheating and desorption device through the hot air inlet of the preheating and desorption device; at least a portion of the flue gas generated by the rotary kiln enters the preheating and desorption device as a desorption carrier gas; The inlet of the first dust removal device is connected to the flue gas outlet of the electric furnace through a pre-dust removal flue, and the outlet of the grinding device is connected to the pre-dust removal flue through an activated carbon output pipeline, and the ground waste active material adsorbs the dioxins in the pre-dust removal flue; The rotary kiln has at least a kiln head and a kiln tail. The rotary kiln is tilted downward from the kiln tail to the kiln head. A burner is provided in the rotary kiln near the kiln head, and the desorption gas interface and the hot air return port of the preheating and desorption device are connected to the kiln head. A feeding cavity is provided between the kiln tail and the discharge port of the preheating device, and the dust removal ash outlet of the preheating and desorption device is connected to the feeding cavity.

2. The flue gas and solid waste coordinated treatment system according to claim 1, characterized in that: The waste active material is waste active coke and / or char.

3. The flue gas and solid waste coordinated treatment system according to claim 1 or 2, characterized in that: The solid waste materials are dust and mud containing zinc and / or iron, and waste activated coke and / or carbon produced by activated carbon desulfurization and denitrification; The recyclable material is the iron-containing material and / or zinc-containing material obtained after the high-temperature reduction reaction of the solid waste material and / or dust ash.

4. The flue gas and solid waste coordinated treatment system according to claim 1, characterized in that: The flue gas and solid waste coordinated treatment system includes a material bin, which is used to store the waste active substances generated by activated carbon desulfurization and denitrification. The material bin has at least a first discharge port and a second discharge port, and the first discharge port and the second discharge port are respectively connected to the inlet of the grinding device and the feed port of the preheating device.

5. The flue gas and solid waste coordinated treatment system according to claim 1, characterized in that: An injection device is provided on the activated carbon output pipeline to inject the ground waste active matter into the flue before dust removal.

6. The flue gas and solid waste coordinated treatment system according to claim 1, characterized in that: The hot air return port of the preheating and desorption device is connected to the kiln head position through a hot air return pipeline, and a second fan is provided on the hot air return pipeline. The desorption gas interface of the preheating and desorption device is connected to the hot air return pipeline through a desorption gas pipeline, and a third fan is provided on the desorption gas pipeline.

7. The flue gas and solid waste coordinated treatment system according to claim 1, characterized in that: An inner cavity is formed inside the preheating and desorption device, and the dust removal ash inlet, the dust removal ash outlet, the desorption gas interface, the hot air inlet and the hot air return port are respectively connected to the inner cavity. A first airtight valve is provided on the dust removal inlet or on the pipeline connected to the dust removal inlet, and a second airtight valve is provided on the dust removal outlet or on the pipeline connected to the dust removal outlet.

8. The flue gas and solid waste coordinated treatment system according to claim 1 or 7, characterized in that: The preheating and desorption device is provided with a plurality of dust removal ash passing pipes, the ends of the plurality of dust removal ash passing pipes are respectively connected to the dust removal ash inlet and the dust removal ash outlet, and the dust removal ash and the desorbed dioxins pass through the plurality of dust removal ash passing pipes; A plurality of baffles are provided inside the preheating and desorption device and between the hot air inlet and the hot air return port. The plurality of baffles are used to increase the flow of the hot air in the preheating and desorption device. The hot air flows in opposite directions to the dust ash. The hot air flows through the outside of the dust ash passage pipeline to heat the dust ash in the dust ash passage pipeline, thereby achieving thermal desorption of dioxins in the dust ash.

9. The flue gas and solid waste coordinated treatment system according to claim 8, characterized in that: The upper and lower parts of the dust removal ash passing pipeline are respectively provided with sealing plates for isolating the dust removal ash from the hot air, and the dust removal ash passing pipeline passes through the sealing plates.

10. The flue gas and solid waste coordinated treatment system according to claim 8, characterized in that: The multiple baffles are arranged at intervals in the direction of the hot air inlet and the hot air return port, one end of the multiple baffles is fixed on the inner wall of the preheating and desorption device, and an overflow gap is left between the other opposite end of the multiple baffles and the inner wall of the preheating and desorption device, and the overflow gaps corresponding to two adjacent baffles are staggered.

11. The flue gas and solid waste coordinated treatment system according to claim 8, characterized in that: The interior of the preheating and desorption device adopts a shell-and-tube heat exchange structure or a partition wall heat exchange structure.

12. The flue gas and solid waste coordinated treatment system according to claim 3, characterized in that: The flue gas and solid waste coordinated treatment system further includes a second dust removal device, which is used to recover the zinc-containing material obtained after the solid waste material and / or dust removal ash undergoes a reduction reaction, the inlet of the second dust removal device is connected to the preheating device through a flue gas pipeline, and the outlet of the second dust removal device is connected to a second chimney through a clean flue gas pipeline, and a fourth fan is provided on the clean flue gas pipeline; A desorption carrier gas inlet is provided at the dust removal ash outlet of the preheating desorption device, and the desorption carrier gas inlet is connected to the clean flue gas pipeline through a desorption carrier gas pipeline.

13. The flue gas and solid waste coordinated treatment system according to claim 3, characterized in that: The flue gas and solid waste coordinated treatment system also includes a cooling device, which is used to cool the iron-containing material obtained after the solid waste material and / or dust ash undergoes a reduction reaction. The cooling device has at least a cold air inlet, a material outlet, a material inlet and a hot air outlet. The material inlet is connected to the rotary kiln, and the hot air outlet is connected to the hot air inlet of the preheating and desorption device.

14. The flue gas and solid waste coordinated treatment system according to claim 13, characterized in that: A fifth fan is provided at the cold air inlet of the cooling device or on a second air duct connected to the cold air inlet.

15. A flue gas and solid waste collaborative treatment method, characterized in that: The flue gas and solid waste collaborative treatment system according to any one of claims 1 to 14 is used to collaboratively treat the flue gas generated by the electric furnace and the added solid waste materials. The method comprises the following steps: Step S1: Grinding the waste active substances generated by activated carbon desulfurization and denitrification into powder; Step S2: using the ground spent active material to adsorb dioxins in the flue gas of the electric furnace; Step S3: separating dust and the waste active material adsorbing the dioxins from the flue gas of the electric furnace; Step S4: desorbing the dioxins adsorbed on the waste active material and preheating the dust removal ash; Step S5: decomposing the desorbed dioxins at high temperature in a rotary kiln; Step S6: preheating the added solid waste material, and subjecting the preheated solid waste material and the desorbed dust to a high-temperature reduction reaction in the rotary kiln; Step S7: Processing the solid waste and recyclable materials generated by high-temperature reduction of dust ash.

16. The flue gas and solid waste coordinated treatment method according to claim 15, characterized in that: In step S1, the waste active material produced by desulfurization and denitrification of activated carbon with a particle size of less than 2 mm is ground into a particle size greater than or equal to 1000 m 2 / g of carbon powder, wherein the particle size of the carbon powder is less than or equal to 250 meshes.

17. The flue gas and solid waste coordinated treatment method according to claim 15, characterized in that: In step S4, the temperature is raised to 450° C. to 600° C. to decompose or desorb dioxins.

18. The flue gas and solid waste coordinated treatment method according to claim 17, characterized in that: A burner is provided at the kiln head of the rotary kiln. The temperature of the high-temperature flue gas generated by the burner is greater than 1100° C., so that dioxins are fully decomposed.

19. The flue gas and solid waste coordinated treatment method according to claim 17, characterized in that: In step S6, at a temperature of 900° C. to 1200° C., the zinc element in the solid waste and / or the dust ash is reduced and volatilized by the activated carbon to form zinc vapor. And / or, the iron elements in the solid waste and dust ash are reduced by the activated carbon to form iron-rich substances.

20. The flue gas and solid waste coordinated treatment method according to claim 19, characterized in that: In step S7, the rotary kiln cools and discharges the iron-rich material, and generates hot air for desorption of dioxins in step S4 and for combustion air in step S5.

21. The flue gas and solid waste coordinated treatment method according to claim 19 or 20, characterized in that: A small portion of the hot flue gas generated in step S6 is returned to the desorption device after being cooled and dust-removed, and is used as a hot carrier gas to carry away the desorbed dioxin gas; In step S7, the coarse zinc powder product formed by condensation of zinc vapor is collected by the second dust collector.

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