Electric furnace dedusting ash microwave treatment method and system

Abstract

The invention relates to the technical field of environmental protection, in particular to an electric furnace fly ash microwave treatment method and system. The method comprises the following steps: uniformly mixing the electric furnace fly ash and a carbon heat reducing agent according to a design ratio to obtain a mixture; the mixture is subjected to microwave heating roasting, heat preservation is conducted for a period of time, and discharging is conducted after cooling; and collecting flue gas generated in the heating and heat preservation process to obtain a zinc-containing material, and collecting the cooled dry material to obtain an iron-containing material. The system comprises a microwave rotary kiln used for disposing electric furnace dedusting ash, and the microwave rotary kiln comprises a feeding system, a transmission system, a kiln body, a microwave heating system and a discharging system and is provided with a cooling system and a dedusting system. According to the invention, the zinc removal rate of 1100-1300 DEG C microwave roasting is greater than or equal to 85% under the high proportion condition that the electric furnace fly ash is greater than or equal to 85%.

Description

Technical Field

[0001] The invention relates to the technical field of environmental protection, and in particular to a microwave treatment method and system for electric furnace dust removal. Background Art

[0002] Compared with traditional blast furnace-converter steelmaking, electric arc furnace steelmaking has a short process and low carbon emission intensity, and is gaining more and more attention. Electric furnace dust is dust collected from flue gas during electric arc furnace steelmaking, and its output accounts for about 1%-2% of the output of electric furnace steelmaking. my country's electric furnace steelmaking capacity is currently about 100 million tons, and the amount of electric furnace ash produced is nearly 2 million tons / year, and it is still increasing. Compared with developed countries, the proportion of electric furnace dust resource utilization in my country is far behind that in developed countries, and it is difficult to dispose of, which has become a major problem facing the sustainable development of the steel industry.

[0003] The composition of electric furnace dust ash is complex, with TFe content of 35-46%, Zn content of 7-25%, and various components such as CaO, MgO, Al2O3, SiO2, S, P, etc. It is a zinc-containing waste. If improperly disposed of, it will not only cause waste of zinc, iron and other resources, but may also cause serious pollution to the soil, water and atmospheric environment, endangering the ecological balance and human health.

[0004] At present, various disposal methods for electric furnace dust have been developed at home and abroad, but they all have certain limitations.

[0005] In pyrometallurgical treatment, electric furnace self-circulation is a simple method, that is, the dust ash is directly returned to the electric furnace for reuse. However, this method has obvious disadvantages. On the one hand, it will increase the cost of electric furnace steelmaking, because the impurities in the dust ash will interfere with the steelmaking process, resulting in increased energy consumption, prolonged smelting time, and thus increased production costs; on the other hand, it will also affect the normal operation of the electric furnace dust removal system, reduce its dust removal efficiency, and increase equipment maintenance costs. Moreover, the ZnO enriched by this method has a low grade, usually less than 50%, and its subsequent utilization value is not high.

[0006] The rotary hearth furnace process is widely used in the treatment of electric furnace dust. It uses the characteristics of rapid heating and reducing atmosphere of the rotary hearth furnace to reduce and volatilize valuable metals such as zinc. However, the electric furnace dust contains a high amount of zinc. During the treatment process, the heat exchanger or boiler is easily blocked by zinc vapor and its oxides, which not only affects the continuous and stable operation of the equipment, but also greatly increases the frequency and cost of equipment maintenance. At the same time, due to the characteristics of the electric furnace dust itself, its addition ratio in the rotary hearth furnace is relatively low, which limits the rotary hearth furnace's ability to handle dust and cannot meet the needs of large-scale disposal.

[0007] The rotary kiln process also faces many problems. The electric furnace dust has a high iron content, and the kiln body is prone to ringing when it is treated at high temperature in the rotary kiln. This will not only hinder the normal movement of materials in the kiln, causing production interruptions, but also reduce the service life of the kiln body and increase the cost of equipment renewal for enterprises. In addition, the proportion of electric furnace dust added to the rotary kiln is also low, making it difficult to achieve efficient disposal of large amounts of dust.

[0008] The wet treatment process aims to separate and recover metals from electric furnace dust through chemical reactions. However, this method is costly and requires a large amount of chemical reagents to be consumed during the treatment process. The procurement, transportation and storage of these reagents require a large amount of capital. In addition, wet treatment will produce a large amount of secondary waste, such as wastewater and waste residue containing heavy metal ions. These secondary wastes are difficult to treat and will cause more serious secondary pollution to the environment if not properly treated.

[0009] With the increasingly stringent environmental protection requirements and the continuous improvement of resource recycling awareness, it is urgent to develop an efficient, environmentally friendly and low-cost electric furnace dust disposal technology. Based on an in-depth study of the existing technology, after preliminary search, a total of two patents closest to this application were retrieved. Among them, the method of microwave hydrogen reduction dezincification of zinc-containing dust with application number 202210251845.2 mixes electric furnace dust, steelmaking ash, converter ash, etc., and although secondary zinc oxide and pellets can be obtained, in order to ensure the C content in the mixed material, the proportion of electric furnace dust must be strictly controlled, thereby reducing the disposal capacity of electric furnace dust. The microwave carbon thermal reduction process of iron-containing dust in steel metallurgy to directly produce sponge iron with application number 200810237006.5 only puts forward requirements for microwave temperature, but lacks detailed design and instructions for the generation of semi-finished coarse sponge iron balls from iron-containing dust in a microwave reduction furnace, and lacks operability in practical applications.

[0010] In summary, the existing electric furnace dust ash disposal technology is difficult to meet the needs of green and sustainable development in the steel industry. In this context, the present invention is committed to developing a new electric furnace dust ash microwave disposal system and method, aiming to break through the bottleneck of existing technologies, achieve high-ratio disposal of electric furnace dust ash, improve zinc removal rate, reduce zinc content of iron-containing materials, and increase resource utilization of iron-containing materials, providing an innovative solution for the steel industry to solve the problem of electric furnace dust ash disposal. Summary of the invention

[0011] In view of the deficiencies in the prior art, the purpose of the present invention is to propose a microwave treatment method and system for electric furnace dust ash, which can increase the treatment capacity of electric furnace dust ash and the high removal rate of zinc in the electric furnace dust ash, and obtain low-zinc iron-containing materials and high-zinc zinc-containing materials.

[0012] To achieve the above object, the present invention adopts the following technical solutions:

[0013] In a first aspect, the present invention provides a microwave treatment method for electric furnace dust removal ash, comprising the following steps:

[0014] According to the designed proportion, the electric furnace dust removal ash and the carbon thermal reducing agent are uniformly mixed to obtain a mixed material;

[0015] The mixed material is subjected to microwave heating and roasting, and kept warm for a period of time, and then discharged after cooling;

[0016] The flue gas generated during the heating and heat preservation process is collected to obtain the zinc-containing material, and the dry material after cooling is collected to obtain the iron-containing material.

[0017] As a further optimization scheme of the present invention, taking the total mass of the electric furnace dust ash and the carbon thermal reducing agent as a benchmark, the mass percentage of the electric furnace dust ash is 85-92%, and the mass percentage of the carbonaceous reducing agent is 8-15%.

[0018] As a further optimization scheme of the present invention, the carbon thermal reducing agent is biomass bamboo charcoal with ash content ≤5%, sulfur ≤0.1%, and fixed carbon ≥90%.

[0019] As a further optimization scheme of the present invention, the temperature of the microwave heating and roasting is 1100-1300°C.

[0020] As a further optimization scheme of the present invention, the iron-containing material contains Zn≤2.42% and TFe≥55%; the zinc-containing material contains ZnO≥60%.

[0021] In the second aspect, the present invention provides a microwave treatment system for electric furnace dust ash, including a microwave rotary kiln for treating electric furnace dust ash, the microwave rotary kiln including a feeding system, a transmission system, a kiln body and a microwave heating system, a discharging system, and is equipped with a cooling system and a dust removal system; a plurality of microwave heating systems are asymmetrically distributed on the kiln body, and the microwave heating system is connected to the cooling system.

[0022] As a further optimization scheme of the present invention, the feeding system includes a feeding hopper, a discharger and a discharge pipe connected in sequence from top to bottom, the discharge pipe is connected to the kiln tube inlet on the kiln body through a first rotating joint, and the kiln tube outlet is connected to the discharge pipe of the discharge system through a second rotating joint.

[0023] As a further optimization scheme of the present invention, the transmission system includes a reducer, a sprocket, a chain and a roller. The reducer is connected to the sprocket through the chain. The sprocket is sleeved and fixed at the inlet of the kiln tube. The reducer can drive the kiln tube to rotate synchronously by driving the sprocket to rotate. The roller is installed at the bottom of the kiln cavity of the kiln body and is used to support the kiln tube.

[0024] As a further optimization scheme of the present invention, the kiln body includes a kiln tube and a kiln cavity, the kiln tube is composed of front and rear end kiln tubes and a middle section kiln tube, the middle section kiln tube and the front and rear end kiln tubes are connected by embedded large and small heads, and are sealed with high temperature resistant sealant after connection; the front and rear end kiln tubes are made of high temperature resistant stainless steel, the middle section kiln tube is made of silicon nitride ceramic, and the kiln tube has a temperature resistance of ≥1300°C; the kiln tube is inclined at an angle of 2-5° through a frame.

[0025] As a further optimization scheme of the present invention, the discharging system includes a discharging pipe, a discharging valve and a receiving bin, and the discharging pipe is connected to the cooling system; the dust removal system includes a dust removal bag and a dust removal barrel, the dust removal bag collects the smoke generated during the heating process, and the dust removal barrel is used to remove dust during the loading and discharging processes.

[0026] The microwave treatment method and system for electric furnace dust removal provided by the present invention realizes efficient treatment of electric furnace dust removal ash through specific process steps, raw material ratios, and equipment structure design, and has significant advantages in increasing the treatment volume, dezincification rate, and resource recycling. The specific beneficial effects are as follows:

[0027] High-ratio disposal of electric furnace dust ash: The present invention takes the total mass of electric furnace dust ash and carbon thermal reducing agent as the benchmark, and the mass percentage of electric furnace dust ash is as high as 85-92%. Compared with the prior art, such as the patent with application number 202210251845.2, the proportion of electric furnace dust ash must be strictly controlled to ensure the C content in the mixed material. The present invention greatly increases the disposal amount of electric furnace dust ash, which is more conducive to large-scale treatment of a large amount of dust ash generated by electric arc furnace steelmaking, meeting the actual needs of the steel industry.

[0028] High zinc removal rate: Under microwave roasting conditions at 1100-1300°C, the present invention can achieve a zinc removal rate of ≥85%. From the data in the examples, after the electric furnace dust ash with different components is treated, ZnO in the zinc-containing material is ≥60%, and Zn in the iron-containing material is ≤2.42%. This achievement effectively solves the problem that the electric furnace dust ash is listed as hazardous waste due to its high zinc content, and reduces the potential pollution risk of zinc to the environment.

[0029] Obtain high-quality iron-containing and zinc-containing materials: The obtained iron-containing materials have TFe≥55%, which can be fully utilized as resources, providing high-quality raw materials for steel production and improving the recycling rate of iron resources; the collected zinc-containing materials have a high ZnO content and have a high subsequent utilization value, realizing the effective recovery of zinc resources and improving the comprehensive recovery level of valuable metals such as zinc and iron in electric furnace dust.

[0030] The equipment has excellent performance and stable operation

[0031] Unique kiln structure: The kiln tube is composed of high-temperature resistant stainless steel kiln tubes at the front and rear ends and a silicon nitride ceramic kiln tube in the middle. It is connected by embedded large and small heads and sealed with high-temperature resistant sealant. It has a temperature resistance of ≥1300℃ and can withstand the high temperature environment of microwave heating while ensuring the stability and sealing of the structure. The kiln tube forms an inclination angle of 2-5° through the frame, which cooperates with the transmission system to facilitate the movement of materials in the kiln and uniform heating.

[0032] Reasonable system configuration: the feeding system, transmission system, discharging system, cooling system and dust removal system work together. The reducer of the transmission system drives the sprocket through the chain, driving the kiln tube to rotate at a speed of 3-18r / min, so that the material can smoothly enter from the feeding system and be discharged from the discharging system after sufficient reaction in the kiln; the cooling system cools the microwave switch power supply, magnetron, discharging pipe, etc. to ensure the normal operation of the equipment; the dust removal system effectively collects the smoke in the heating process and the dust in the feeding and discharging process, reduces dust emissions and protects the environment.

[0033] Significant environmental benefits: It avoids the drawbacks of traditional pyrometallurgical and hydrometallurgical processes. Compared with the pyrometallurgical treatment of electric furnace self-circulation, rotary hearth furnace process, and rotary kiln process, it does not increase steelmaking costs, affect the operation of the dust removal system, equipment blockage, ring formation, and other issues; compared with the hydrometallurgical process, it does not require the consumption of a large amount of chemical reagents, avoids the generation of a large amount of difficult-to-treat secondary waste, reduces secondary pollution to the environment, meets the trend of increasingly stringent environmental protection requirements, and promotes the green and sustainable development of the steel industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 The present invention is a main process flow chart of a microwave treatment method for electric furnace dust removal ash.

[0035] Figure 2 The present invention is a schematic structural diagram of a microwave treatment system for electric furnace dust removal.

[0036] In the figure: 1. feed hopper; 2. discharger; 3. discharge pipe; 4. first rotary joint; 5. sprocket; 6. chain; 7. roller; 8. temperature measuring thermocouple; 9. furnace pressure detection port; 10. protective gas inlet; 11. kiln cavity; 12. kiln tube; 13. microwave heating system; 14. second rotary joint; 15. water jacket; 16. water cooler; 17. water pipe; 18. discharge pipe; 19. discharge valve; 20. receiving bin; 21. dust removal system. DETAILED DESCRIPTION

[0037] In order to enable those skilled in the art to better understand the technical solution of the present invention, the preferred implementation scheme of the present invention is described below in conjunction with specific embodiments, but it should not be understood as limiting the present invention and is only used as an example.

[0038] The experimental methods or test methods described in the following examples are conventional methods unless otherwise specified; the reagents and materials are obtained from conventional commercial channels or prepared by conventional methods unless otherwise specified.

[0039] like Figure 1 As shown, the present invention provides a microwave treatment method for electric furnace dust, comprising the following steps:

[0040] (1) uniformly mixing the electric furnace dust and the carbon thermal reducing agent according to the designed ratio to obtain a mixture;

[0041] (2) subjecting the mixed material to microwave heating and roasting, and keeping the temperature for a period of time, and then discharging the mixed material after cooling;

[0042] (3) Collect the flue gas generated during the heating and heat preservation process to obtain zinc-containing material (i.e., secondary zinc oxide, also known as crude zinc oxide), and collect the dried material after cooling to obtain iron-containing material.

[0043] The total mass of the electric furnace dust removal ash and the carbon thermal reducing agent is used as a benchmark, the mass percentage of the electric furnace dust removal ash is 85-92%, and the mass percentage of the carbon-containing reducing agent is 8-15%. The carbon thermal reducing agent is a biomass bamboo charcoal with an ash content of ≤5%, a sulfur content of ≤0.1%, and a fixed carbon content of ≥90%. The microwave heating and roasting temperature is 1100-1300°C. The iron-containing material contains Zn≤2.42%, TFe≥55%; the zinc-containing material contains ZnO≥60%.

[0044] The main chemical composition of electric furnace dust is shown in Table 1.

[0045] Table 1 Chemical composition of electric furnace dust (wt%)

[0046]

[0047] like Figure 2 As shown, the present invention also provides a microwave treatment system for electric furnace dust, including a microwave rotary kiln for treating electric furnace dust, the microwave rotary kiln includes a feeding system, a transmission system, a kiln body and a microwave heating system 13, a discharging system, and is equipped with a cooling system and a dust removal system 21. The specific structure is as follows:

[0048] The electric furnace dust removal ash mixture enters the feeding system by its own weight. The feeding system includes a feeding hopper 1, a discharger 2 and a discharge pipe 3 connected in sequence from top to bottom. The discharge pipe 3 is L-shaped. The discharge pipe 3 is connected to the inlet of the kiln tube 12 on the kiln body through a first rotary joint 4. The static end of the first rotary joint 4 is connected to the outlet flange of the discharge pipe 3, and its rotating end is connected to the inlet flange of the kiln tube 12. The outlet of the kiln tube 12 is connected to the discharge pipe 18 of the discharge system through a second rotary joint 14. The static end of the second rotary joint 14 is connected to the inlet flange of the discharge pipe 18, and its rotating end is connected to the outlet flange of the kiln tube 12.

[0049] The transmission system includes a reducer, a sprocket 5, a chain 6 and a roller 7. The reducer is connected to the sprocket 5 through the chain 6. The sprocket 5 is fixed at the inlet of the kiln tube 12. The reducer can drive the sprocket 5 to rotate, thereby driving the kiln tube 12 to rotate synchronously. The roller 7 is installed at the bottom of the kiln cavity 11 of the kiln body and is used to support the kiln tube 12. The transmission system is used to rotate the kiln tube 12 at a speed of 3-18r / min, and the material enters the discharge system from the kiln tube 12 through rotation.

[0050] The kiln body includes a kiln tube 12, a kiln cavity 11 and a waveguide port. The kiln tube 12 is composed of front and rear end kiln tubes 12 and a middle section kiln tube 12. The middle section kiln tube 12 is connected to the front and rear end kiln tubes 12 by embedded large and small heads, and is sealed by high temperature resistant sealant after connection. The front and rear end kiln tubes 12 are made of high temperature resistant stainless steel, the middle section kiln tube 12 is made of silicon nitride ceramics, and the kiln tube 12 has a temperature resistance of ≥1300°C. The kiln tube 12 is inclined at an angle of 2-5° through a frame.

[0051] The kiln cavity 11 has an inner diameter of ≤1m and is used to wrap and protect the kiln tube 12. It is equipped with a furnace pressure detection port 9, a protective gas inlet 10, a temperature measuring thermocouple 8 inlet, and fixes the microwave heating system 13. The kiln tube 12 and the kiln cavity 11 are filled with thermal insulation materials, but at the same time, the heating system channel is guaranteed to be smooth.

[0052] A plurality of microwave heating systems 13 are asymmetrically distributed on the kiln cavity 11. The microwave heating system 13 includes a microwave power source, a microwave generator and a microwave deflector. The microwave heating system 13 and the temperature measuring thermocouple 8 are used together to control the microwave heating speed and heating temperature. The microwave generator includes a microwave emitting magnetron and a microwave absorber. The microwave power source, the magnetron and the microwave absorber are connected to the cooling system, and cooling and excess microwave absorption are performed by cooling water. The electric furnace dust removal ash mixture is heated to 1100-1300°C in the microwave rotary kiln and then discharged.

[0053] The cooling system includes circulating water, water chiller 16, water pipe 17, valve and water jacket 15, etc. The cooling water system is used to cool the microwave switch power supply, magnetron, discharge pipe 18, etc. The electric furnace dust removal ash mixture is cooled to ≤30℃ and enters the receiving bin 20. The purpose of cooling is to facilitate storage and avoid high temperature materials that may cause burns to the storage materials and personnel.

[0054] The discharge system includes a discharge pipe 18, a discharge valve 19 and a receiving bin 20. The discharge pipe 18 is covered with a water jacket 15 of a cooling system for cooling the material. The receiving bin 20 collects the electric furnace dust ash mixture after roasting to form an iron-containing material with Zn≤2.42% and TFe≥55%.

[0055] The dust removal system 21 includes a dust removal bag and a dust removal barrel. The dust removal bag collects the flue gas generated during the heating process, and the dust removal barrel is used to remove dust during the feeding and discharging process. The zinc-containing material collected by the dust removal bag contains ZnO≥60%.

[0056] The present invention is further described in detail below with reference to specific embodiments and comparative examples.

[0057] Embodiment 1:

[0058] 1) After the electric furnace dust with a total iron content of 45.26% and a Zn content of 7.88% and the biomass charcoal with a fixed carbon content of 87.55% are uniformly mixed in a ratio of 46:4, the heating system, transmission system, cooling system and dust removal system of the microwave rotary kiln are started, the rotary kiln starts to rotate at a rate of 12r / min, and then the mixer is started to unload the material.

[0059] 2) The electric furnace dust removal ash mixture enters the kiln body through the microwave rotary kiln feeding system. After the temperature reaches 1100℃ and is kept warm for 10 minutes, the discharging system is started. During the discharging process, the material temperature gradually decreases to 30℃ before discharging.

[0060] 3) Iron-containing material with TFe 62.23% and Zn 0.96% is obtained in the receiving bin.

[0061] 4) The ZnO content in the zinc-containing material obtained by the dust removal bag is 62.58%.

[0062] Embodiment 2:

[0063] 1) After the electric furnace dust with a total iron content of 44.96% and a Zn content of 19.13% and the biomass charcoal with a fixed carbon content of 78.07% are evenly mixed in a ratio of 17:3, the microwave rotary kiln heating system, transmission system, cooling system and dust removal system are started, the rotary kiln starts to rotate at a rate of 8r / min, and then the mixer is started to unload the material.

[0064] 2) After the electric furnace dust removal ash mixture enters the microwave rotary kiln body through the microwave rotary kiln feeding system, the temperature reaches 1100℃ and is kept warm for 10 minutes, and then the discharging system is started. During the discharging process, the material temperature gradually drops to 30℃ before discharging.

[0065] 3) Iron-containing material with TFe 60.16% and Zn 1.62% is obtained in the receiving bin.

[0066] 4) The ZnO content in the zinc-containing material obtained by the dust removal bag is 63.24%.

[0067] Embodiment 3:

[0068] 1) After the electric furnace dust removal ash with a total iron content of 36.48% and a Zn content of 23.56% and the biomass charcoal with a fixed carbon content of 90.06% are uniformly mixed in a ratio of 17:3, the microwave rotary kiln heating system, transmission system, cooling system and dust removal system are started, the rotary kiln starts to rotate at a rate of 5r / min, and then the mixer is started to unload the material.

[0069] 2) After the electric furnace dust removal ash mixture enters the microwave rotary kiln body through the microwave rotary kiln feeding system, the temperature reaches 1300℃ and is kept warm for 10 minutes, and then the discharging system is started. During the discharging process, the material temperature gradually drops to 30℃ before discharging.

[0070] 3) Iron-containing material with TFe 55.38% and Zn 0.86% is obtained in the receiving bin.

[0071] 4) The ZnO content in the zinc-containing material obtained by the dust removal bag is 72.02%.

[0072] The above description only provides a specific exemplary description of the present invention. It should be noted that the specific implementation of the present invention is not limited to the above method. As long as various non-substantial improvements are made using the technical concept and technical solution of the present invention, or the technical concept and technical solution of the present invention are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. A microwave treatment method for electric furnace dust removal, characterized in that: The steps include: According to the designed proportion, the electric furnace dust removal ash and the carbon thermal reducing agent are uniformly mixed to obtain a mixed material; The mixed material is heated and roasted by microwave, and kept warm for a period of time, and then discharged after cooling; The flue gas generated during the heating and heat preservation process is collected to obtain the zinc-containing material, and the dry material after cooling is collected to obtain the iron-containing material.

2. The microwave treatment method for electric furnace dust removal according to claim 1 is characterized in that: Taking the total mass of the electric furnace dust and the carbon thermal reducing agent as a reference, the mass percentage of the electric furnace dust is 85-92%, and the mass percentage of the carbonaceous reducing agent is 8-15%.

3. The microwave treatment method for electric furnace dust removal according to claim 1 is characterized in that: The carbon thermal reducing agent is biomass bamboo charcoal with ash content ≤5%, sulfur ≤0.1% and fixed carbon ≥90%.

4. The microwave treatment method for electric furnace dust according to claim 1, characterized in that: The temperature of the microwave heating and roasting is 1100-1300° C., and the insulation time is 10-15 minutes.

5. The microwave treatment method for electric furnace dust removal according to claim 1, characterized in that: The iron-containing material contains Zn≤2.42% and TFe≥55%; the zinc-containing material contains ZnO≥60%.

6. A microwave treatment system for electric furnace dust removal, characterized in that: The invention comprises a microwave rotary kiln for treating electric furnace dust, the microwave rotary kiln comprising a feeding system, a transmission system, a kiln body and a microwave heating system (13), a discharging system, and is equipped with a cooling system and a dust removal system (21); a plurality of microwave heating systems (13) are asymmetrically distributed on the kiln body, and the microwave heating system (13) is connected to the cooling system.

7. The microwave treatment system for electric furnace dust removal according to claim 6 is characterized in that: The feeding system comprises a feeding hopper (1), a discharger (2) and a discharge pipe (3) which are connected in sequence from top to bottom; the discharge pipe (3) is connected to an inlet of a kiln tube (12) on the kiln body via a first rotating joint (4); and the outlet of the kiln tube (12) is connected to a discharge pipe (18) of the discharge system via a second rotating joint (14).

8. The microwave treatment system for electric furnace dust removal according to claim 6, characterized in that: The transmission system comprises a reducer, a sprocket (5), a chain (6) and a roller (7); the reducer is connected to the sprocket (5) through the chain (6); the sprocket (5) is sleeved and fixed at the inlet of the kiln tube (12); the reducer can drive the sprocket (5) to rotate, thereby driving the kiln tube (12) to rotate synchronously; the roller (7) is installed at the bottom of the kiln cavity (11) of the kiln body and is used to support the kiln tube (12).

9. The microwave treatment system for electric furnace dust removal according to claim 6, characterized in that: The kiln body comprises a kiln tube (12) and a kiln cavity (11); the kiln tube (12) comprises front and rear end kiln tubes (12) and a middle section kiln tube (12); the middle section kiln tube (12) and the front and rear end kiln tubes (12) are connected by using a large and small head embedded connection, and are sealed by using a high temperature resistant sealant after connection; the front and rear end kiln tubes (12) are made of high temperature resistant stainless steel, the middle section kiln tube (12) is made of silicon nitride ceramic, and the kiln tube (12) has a temperature resistance of ≥1300°C; the kiln tube (12) is inclined at an angle of 2-5° through a frame.

10. The microwave treatment system for electric furnace dust removal according to claim 6, characterized in that: The discharge system comprises a discharge pipe (18), a discharge valve (19) and a receiving bin (20), wherein the discharge pipe (18) is connected to the cooling system; the dust removal system (21) comprises a dust removal bag and a dust removal barrel, wherein the dust removal bag collects the smoke generated during the heating process, and the dust removal barrel is used for dust removal during the feeding and discharging process.

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