Sintering machine head flue gas treatment device and method

Abstract

A sintering machine head flue gas treatment device, the device comprises a dust collector (1) and a desulfurization and denitration device (2); the flue gas outlet of the dust collector (1) is connected to the desulfurization and denitration device (2) via an air duct (L1); a fan (3) is arranged on the air duct (L1); the characteristic is that: according to the direction of the flue gas, the dust collector (1) is provided with an electric zone (4), a transition zone (5), and a bag zone (6) in sequence; and a dust collector ash hopper is arranged below the electric zone (4) and the bag zone (6). The use of the present invention can greatly reduce the dust content in the flue gas of the sintering machine head, solve the problem of high dust emission concentration of the existing sintering machine head dust collector, and at the same time can also absorb a small amount of SO2 in the flue gas to reduce the processing load of subsequent flue gas purification facilities, meet the ultra-low emission standard, and have good economic benefits.

Description

Technical Field

[0001] The invention relates to a sintering machine head smoke treatment technology, and in particular to a sintering machine head smoke treatment device and method, belonging to the sintering smoke treatment technical field. Background Art

[0002] With the development of modern industry and the improvement of people's quality of life, the requirements for environmental protection are becoming higher and higher. Safe production and clean production have become the symbols of modern corporate civilization.

[0003] In the sintering production of the steel industry, the dust content of the flue gas from the sintering machine head is high, the flue gas composition is complex, and the moisture content of the flue gas is high. Due to the large fluctuations in the production process operation, there are many uncontrollable factors in the flue gas. In order to achieve ultra-low emissions, high technical requirements must be adopted.

[0004] The sintering machine head flue gas has the following characteristics:

[0005] (1) The sintering flue gas volume is large and fluctuates greatly: the air volume per unit sintering area is about 4000-6000m per hour 3 / ton of sintered ore.

[0006] (2) The sintering flue gas carries a large amount of dust (1-5 g / Nm 3 ).

[0007] (3) Flue gas temperature fluctuates greatly (80-180°C).

[0008] (4) The water vapor content of flue gas is relatively high (8-20%) and the dew point temperature is relatively high (≥60°C).

[0009] (5) The flue gas contains high oxygen content (15% to 18%).

[0010] (6) The flue gas composition is complex: containing SO2, K, Na, Si, Mg, Al, Zn, As, Cl, Fe, Ca, etc.

[0011] (7)SO2 and NO x Concentration: SO2 concentration 300~5000mg / Nm 3 , NO x Concentration: 150~600mg / Nm 3 .

[0012] (8) The particle size of dust in flue gas is: ≥50μm accounts for 25%, 10-50μm accounts for 40%, and ≤10μm accounts for 35%.

[0013] At present, the dust collectors used for the flue gas at the sintering machine head are almost all electrostatic precipitators, which are subsequently equipped with other flue gas purification facilities (desulfurization and denitrification). Figure 1(Existing technology for treating flue gas from the head of sintering machine): The flue gas from the head of sintering machine enters the electrostatic precipitator from the inlet of the electrostatic precipitator, and is discharged from the outlet of the electrostatic precipitator after electrostatic precipitator removal. The flue gas after dust removal is then drawn into the desulfurization and denitrification device through the air duct and the fan for desulfurization and denitrification treatment, and then discharged to the outside; the dust obtained after electrostatic precipitator removal in the electrostatic precipitator falls into the ash hopper of the electrostatic precipitator below the electrostatic precipitator, and is transported away after the ash hopper is full. It is generally directly used as a sintering raw material for batching again. In the existing technology, after the electrostatic precipitator removes dust from the flue gas from the head of the sintering machine, the dust concentration can be reduced to 30-50 mg / Nm 3 . However, due to the uniform electric field strength in the existing electrostatic precipitator, its dust removal efficiency is low. There is still a lot of dust in the flue gas after the electrostatic precipitator. These dusts are fine dusts with high resistivity, which are difficult to capture by the electrostatic precipitator. It is very difficult to rely on the electrostatic precipitator to further reduce the dust emission concentration of the flue gas from the sintering machine head. The dust in the flue gas from the sintering machine head will also have an adverse effect on the subsequent desulfurization and denitrification processes and equipment. Therefore, as environmental protection and emission requirements become more and more stringent, it is necessary to reduce the dust content of the flue gas from the sintering machine head as low as possible. At the same time, since the dust collected by the electrostatic precipitator contains a lot of chlorides, alkali metals, etc., which are all substances that are harmful to sintering, directly using them as sintering raw materials to participate in the batching again will affect the quality of the sintered ore. When these harmful substances accumulate too much in the sintered ore, it will also have an adverse effect on the subsequent blast furnace ironmaking. Summary of the invention

[0014] In view of the problems existing in the above-mentioned prior art, the present invention proposes a sintering machine head flue gas treatment device and method. The device of the present invention comprises a dust collector and a desulfurization and denitrification device, wherein the dust collector is provided with an electric zone, a transition zone and a bag zone. A plurality of electric fields with different intensities are provided in the electric zone, a spraying device is provided in the transition zone, and a plurality of filter bags with different mesh diameters are provided in the bag zone. In the method of the present invention, the sintering machine head flue gas passes through the electric zone, the transition zone and the bag zone in the dust collector in sequence for dust removal treatment, and the flue gas after dust removal treatment is discharged after being treated by the desulfurization and denitrification device. In the present invention, the electric field intensity in the electric zone and the mesh diameter of the filter bag show a trend of change in strength and size, which can effectively capture the dust of each level in the sintering machine head flue gas in a targeted manner, thereby greatly reducing the dust content in the sintering machine head flue gas; a specific additive is sprayed in the transition zone to treat the flue gas, that is, while further improving the dust removal effect, SO2 in the flue gas can also be adsorbed to reduce the processing load of the subsequent flue gas purification facilities, achieve ultra-low emission standards, and have good economic benefits.

[0015] According to a first embodiment of the present invention, a sintering machine head fume treatment device is provided.

[0016] A sintering machine head flue gas treatment device includes a dust collector and a desulfurization and denitration device. The flue gas outlet of the dust collector is connected to the desulfurization and denitration device via an air duct. A fan is provided on the air duct. According to the direction of the flue gas, an electric zone, a transition zone, and a bag zone are sequentially provided in the dust collector. A dust collector ash hopper is provided below the electric zone and the bag zone.

[0017] In the present invention, the dust collector further comprises a dust collector bell mouth arranged at the flue gas inlet. The large opening end of the dust collector bell mouth is connected to the electric zone. Preferably, an air flow distribution plate is arranged in the dust collector bell mouth. Preferably, the number of the air flow distribution plates is multiple. According to the direction of the flue gas, the size of each air flow distribution plate increases successively with the widening of the dust collector bell mouth.

[0018] Preferably, the airflow distribution plate is provided with multiple rows of openings along the height direction of the dust collector, wherein the diameter of each row of openings increases successively from the middle of the airflow distribution plate to the upper and lower sides, and the number of openings in each row decreases successively.

[0019] In the present invention, a spraying device is provided in the transition zone, and the spraying device is arranged at the top and the bottom of the transition zone, and the nozzle of the spraying device faces the center of the transition zone.

[0020] Preferably, the device further comprises an additive chamber and a nitrogen delivery pipeline. The additive chamber is connected to the spraying device via the additive delivery pipeline. The nitrogen delivery pipeline is also connected to the spraying device.

[0021] In the present invention, m electric fields are arranged in the electric zone. The strength of each electric field increases in turn according to the direction of the flue gas. An electric zone ash hopper is arranged under each electric field. Among them, m is 1 to 8, preferably 2 to 4.

[0022] In the present invention, n sub-bag areas are provided in the bag area. Filter bags are provided between adjacent sub-bag areas. The filter bags are provided with evenly distributed mesh holes. According to the direction of the smoke, the diameter of the mesh holes on each filter bag increases successively. Among them, n is 1 to 8, preferably 2 to 4. A bag area ash hopper is provided under each sub-bag area.

[0023] In the present invention, the device further comprises an additive scraper conveyor, a detection and material distribution device, and a mixing device arranged downstream of the bag area ash hopper. The additive scraper conveyor is arranged below the discharge port of the bag area ash hopper. The discharge end of the additive scraper conveyor is connected to the feed port of the detection and material distribution device. The first discharge port of the detection and material distribution device is connected to the additive delivery pipeline via the additive replenishment pipeline. The second discharge port of the detection and material distribution device is connected to the feed port of the mixing device.

[0024] Preferably, the device further comprises a circulation bin and a first crushing device arranged between the additive scraper conveyor and the detection and material distribution device. The discharge end of the additive scraper conveyor is connected to the feed port of the circulation bin. The discharge port of the circulation bin is connected to the feed port of the first crushing device. The discharge port of the first crushing device is connected to the feed port of the detection and material distribution device.

[0025] In the present invention, a sintered ash scraper conveyor is provided below the discharge port of the ash hopper of the power zone, and the discharge end of the sintered ash scraper conveyor is connected to the feed port of the mixing device.

[0026] Preferably, the device further comprises a sintering dust bin and a second crushing device arranged between the sintering ash scraper conveyor and the mixing device. The discharge end of the sintering ash scraper conveyor is connected to the feed port of the sintering dust bin. The discharge port of the sintering dust bin is connected to the feed port of the second crushing device. The discharge port of the second crushing device is connected to the feed port of the mixing device.

[0027] In the present invention, the device further comprises a dissolving and washing device, a filtering device, a drying device, a third crushing device, and a sintering batching system. The discharge port of the mixing device is connected to the feed port of the dissolving and washing device. The discharge port of the dissolving and washing device is connected to the feed port of the filtering device. The solid outlet of the filtering device is connected to the feed port of the drying device. The discharge port of the drying device is connected to the feed port of the third crushing device. The discharge port of the third crushing device is connected to the sintering batching system.

[0028] Preferably, the device further comprises a purification and impurity removal device, an extraction device, and a valuable metal recovery device. The liquid outlet of the filter device is connected to the inlet of the purification and impurity removal device. The outlet of the purification and impurity removal device is connected to the inlet of the extraction device. The outlet of the extraction device is connected to the valuable metal recovery device. Preferably, the liquid outlet of the filter device is connected to the liquid inlet of the washing device.

[0029] In the present invention, a double-layer ash discharge valve is provided below the discharge port of the power zone ash hopper and the bag zone ash hopper. A vibration device is provided at the discharge port of the power zone ash hopper and the bag zone ash hopper. Preferably, a heating device is also provided in the power zone ash hopper and the bag zone ash hopper.

[0030] Preferably, the upper part of the side wall of the power zone ash hopper and the bag zone ash hopper is provided with an upper material level meter, and the lower part of the side wall is provided with a lower material level meter. Preferably, the side wall of the power zone ash hopper and the bag zone ash hopper is also provided with a temperature detection device.

[0031] According to a second embodiment of the present invention, a method for treating flue gas from a sintering machine head is provided.

[0032] A method for treating sintering machine head flue gas or a method for treating sintering machine head flue gas using the device described in the first embodiment, the method comprising the following steps:

[0033] 1) The flue gas from the sintering machine head is connected to the flue gas inlet of the dust collector. The flue gas is first dispersed by the air flow distribution plate arranged at the bell mouth of the dust collector, and then the flue gas enters the electric area evenly and dispersedly.

[0034] 2) The flue gas passes through each electric field in the electric zone in turn. As the electric field strength increases, the large and medium dust particles in the flue gas settle into the ash hopper of the electric zone below each electric field after being charged. The flue gas after removing the medium and large dust particles enters the transition zone.

[0035] 3) In the transition zone, the spraying device sprays additives into the flue gas, and the additives enter the bag area together with the flue gas. The additives form a coating on the filter bags in the bag area. The small dust particles in the flue gas are adsorbed on the surface of the filter bag covered with the additives. As the thickness of the small dust particles covering the filter bag increases, the filter bag begins to be cleaned, and the small dust particles are cleaned and fall into the bag area ash hopper under each sub-bag area.

[0036] 4) The flue gas after dust removal enters the desulfurization and denitrification device under the action of the fan, and the flue gas is discharged after desulfurization and denitrification treatment.

[0037] In the present invention, the method further comprises:

[0038] 5) The medium and large dust particles falling into the ash hopper of the electric zone in step 2) are unloaded into the sintering ash scraper conveyor, and the sintering ash scraper conveyor then conveys the medium and large dust particles to the sintering dust bin. The medium and large dust particles are crushed by the second crushing device and then conveyed to the mixing device.

[0039] 6) The small dust particles falling into the ash hopper of the bag area in step 3) are unloaded into the additive scraper conveyor, and the additive scraper conveyor then transports these small dust particles to the circulation bin. The accumulated small dust particles agglomerate in the circulation bin, and the agglomerated dust is crushed by the first crushing device and then transported to the mixing device.

[0040] 7) The mixing device mixes the dust from the sintering dust bin and the circulating bin, and then passes it into the dissolving and washing device. The dissolving and washing device dissolves and washes the mixed dust. The dissolved and washed dust is filtered in the filtering device to obtain filter cake and filtrate.

[0041] 8) Part of the filtrate is circulated to the dissolution and washing device to continue to participate in the dissolution and washing of dust, and the remaining filtrate is passed into the purification and impurity removal device for purification and impurity removal, and then extracted by the extraction device to obtain valuable metals.

[0042] 9) The filter cake is first dried by a drying device and then crushed by a third crushing device to obtain iron-containing powder; the iron-containing powder is sent to a sintering batching system to complete sintering batching and then sintered.

[0043] Preferably, step 6) further includes the step of detecting and sorting the dust after the first crushing device is crushed, specifically: firstly, the dust after the first crushing device is crushed is transported to the detection and sorting device. The detection and sorting device detects the composition of the dust, and when the content of the additive in the dust exceeds 40% (preferably exceeds 50%), the detection and sorting device transports the dust containing the additive to the spraying device in the transition zone. Otherwise, the detection and sorting device transports the dust to the mixing device.

[0044] In step 3) of the present invention, the additive is calcium carbonate. The particle size of the additive is 1 to 3.5 μm, preferably 1.5 to 2 μm. Preferably, in the transition zone, the additive sprayed by the spraying device reacts with SO2 in the flue gas to form a desulfurization byproduct, which enters the bag zone and falls into the bag zone ash hopper.

[0045] In view of the problem of excessively high dust emission concentration in the dust collector of the sintering machine head in the prior art, the present invention proposes a sintering machine head flue gas treatment device and method. The device of the present invention comprises a dust collector and a desulfurization and denitrification device, wherein the dust collector is provided with an electric zone, a transition zone and a bag zone. A plurality of electric fields with different intensities are provided in the electric zone, a spraying device is provided in the transition zone, and a plurality of filter bags with different mesh diameters are provided in the bag zone. In the method of the present invention, the flue gas of the sintering machine head passes through the electric zone, the transition zone and the bag zone in the dust collector in turn for dust removal treatment, and the flue gas after dust removal treatment is then discharged after being treated by the desulfurization and denitrification device. In the present invention, the electric field intensity in the electric zone and the mesh diameter of the filter bag show a trend of change in strength and size, which can effectively capture the dust of each level in the flue gas of the sintering machine head in a targeted manner, thereby greatly reducing the dust content in the flue gas of the sintering machine head (through experimental research, the use of this application can reduce the dust content of the flue gas of the sintering machine head to 10mg / Nm 3 ); spraying specific additives in the transition zone to treat the flue gas, which can further improve the dust removal effect and absorb SO2 in the flue gas to reduce the processing load of subsequent flue gas purification facilities, achieve ultra-low emission standards, and have good economic benefits.

[0046] In the present invention, the sintering machine head flue gas treatment device includes a dust collector and a desulfurization and denitrification device arranged downstream of the dust collector. According to the direction of the flue gas, an electric zone, a transition zone and a bag zone are provided in the dust collector, and a dust collector ash hopper is provided below the electric zone and the bag zone. In the present application, multiple electric fields are provided in the electric zone of the dust collector. According to the direction of the flue gas, the strength of each electric field is successively enhanced, and an electric zone ash hopper is provided below each electric field. The number of electric fields in the electric zone can be set as needed, for example, the number of electric fields is 1 to 8, preferably 2 to 4. For example, three electric fields are provided in the electric zone, which are the first electric field, the second electric field, and the third electric field in order according to the direction of the flue gas, and an electric zone ash hopper is provided below each electric field. Among them, the strength of the first electric field is less than the strength of the second electric field, and the strength of the third electric field is less than the strength of the third electric field. After the flue gas from the sintering machine head enters the electric zone, since the intensity of the first electric field is the lowest, the large dust particles in the flue gas are charged in this area and fall into the ash hopper of the electric zone below the first electric field; the electric field intensities of the second and third electric fields increase successively, and the medium dust particles in the flue gas are charged in this area successively, and then settle and fall into the ash hopper of the electric zone below the second and third electric fields successively. Therefore, the electric field intensities in the electric zone of the dust collector of the present application show a trend of strong and weak changes, which can effectively capture the dust of each level in the flue gas from the sintering machine head in a targeted manner, improve the dust removal efficiency, and save energy consumption at the same time.

[0047] The present invention provides a plurality of sub-bag areas in the bag area of ​​the dust collector, and a bag area ash hopper is provided under each sub-bag area. Filter bags are provided between adjacent sub-bag areas, and the filter bags are provided with evenly distributed mesh holes. According to the direction of the flue gas, the diameter of the mesh holes of each filter bag increases successively. The number of sub-bag areas in the bag area can be the same as the number of filter bags, or multiple filter bags can be provided in each sub-bag area, in which case the diameters of the mesh holes of the filter bags in each sub-bag area are the same. The number of sub-bag areas in the bag area can be set as required, for example, the number of filter bags is 1 to 8, preferably 2 to 4. For example, three filter bags are provided in the bag area, which are the first filter bag, the second filter bag, and the third filter bag in order according to the direction of the flue gas. Among them, the mesh diameter of the first filter bag is less than the mesh diameter of the second filter bag, which is less than the mesh diameter of the third filter bag. Correspondingly, the three filter bags divide the bag area into three sub-bag areas, which are the first sub-bag area, the second sub-bag area, and the third sub-bag area in order, and a bag area ash hopper is provided under each sub-bag area, such as Figure 2 As shown. After dust removal in the electric zone, the medium and large dust particles in the flue gas from the sintering machine head are removed, and then the flue gas passes through the first sub-bag area, the second sub-bag area, and the third sub-bag area for dust removal in turn, and the content of small dust particles in the flue gas is also greatly reduced. Therefore, the dust collector of the present application sets multiple electric fields with different intensities in the electric zone, and then sets multiple filter bags with different mesh diameters in the bag area, which can greatly improve the dust removal efficiency and solve the problem that small dust particles and fine dust in the flue gas from the sintering machine head in the prior art are difficult to remove and capture, thereby greatly reducing the dust content in the flue gas from the sintering machine head and reaching the ultra-low emission standard.

[0048] In the present invention, the transition zone is arranged between the electric zone and the bag zone in the dust collector, and spraying devices are arranged above and below the transition zone. The spraying device is provided with two inlets, one of which is connected to the additive delivery pipeline, and the input end of the additive delivery pipeline is connected to the additive bin; the other inlet is connected to compressed nitrogen (for protection). A plurality of nozzles are arranged at the outlet of the spraying device, and the plurality of nozzles are arranged toward the center of the transition zone to ensure that the spraying device has no dead angle when spraying in the transition zone, and can spray the additive evenly and dispersedly in the entire transition zone. Among them, the additive can be selected as calcium carbonate. In the present invention, on the one hand, the additive can react with SO2 in the flue gas to form a small amount of desulfurization by-products, thereby reducing the emission concentration of SO2 in the flue gas after dust removal, thereby reducing the processing load of subsequent flue gas purification facilities; at the same time, the remaining additive will enter the bag area together with the flue gas, and the additive will form a wrapping coating on the filter bag in the bag area, covering the surface of the filter bag to protect the filter bag and prevent the sharp dust ions from wearing the filter bag; moreover, in the bag area of ​​the dust collector, small particles of dust with high resistivity and fine particle size that are difficult to remove in the flue gas (these dusts are difficult to charge in the charging area and cannot be captured) are adsorbed on the surface of the filter bag covered with the additive, so that the filter bag can easily clean and capture the dust during the back-blowing cleaning operation, the cleaning of the filter bag becomes more thorough, and the dust removal efficiency is further improved.

[0049] Preferably, the dust collector further comprises a dust collector bell mouth arranged at the flue gas inlet. The small end of the dust collector bell mouth is connected to the flue gas inlet of the dust collector, and the large end (i.e., the large opening end) of the dust collector bell mouth is connected to the electric zone. A plurality of airflow distribution plates are arranged in the dust collector bell mouth, and the size of each airflow distribution plate increases successively with the widening of the dust collector bell mouth, until the airflow distribution plate close to the electric zone is substantially consistent with the size of the dust collector electric zone. Along the height direction of the dust collector, a plurality of rows of openings are arranged on the airflow distribution plate. From the middle of the airflow distribution plate to the upper and lower sides, the diameter of each row of openings increases successively, and the number of each row of openings decreases successively. It should be noted that the opening diameter increases from the middle to the upper and lower sides as described here. It can be that only one row of openings of each size is set, for example, from the middle to the upper and lower sides, a row of small holes, a row of medium holes, a row of medium-large holes, a row of large holes... are set in sequence, that is, a row of openings with the smallest size (i.e., small holes) is set in the middle of the airflow distribution plate, and then the openings of other sizes are symmetrically distributed up and down; it can also be that the openings of the same size are set in several rows, for example Figure 4In the middle of the airflow distribution plate, 5 rows of small holes with the smallest size are set, and then medium holes, medium-large holes, large holes... are set in sequence from the middle to the upper and lower sides. Correspondingly, as the diameter of each row of openings increases, the number of openings in each row decreases successively. According to the flow law of flue gas, this application sets the smallest and largest number of openings in the middle of the airflow distribution plate, and then the size of the openings gradually increases from the middle to the upper and lower sides, and the number of openings gradually decreases. Such a distribution of large and small holes can disperse the flue gas more evenly, and with the subsequent strong and weak electric fields, large particles of dust can be captured efficiently. At the same time, the flue gas flow rate is smooth, the pressure is stable, and the dust removal efficiency is higher.

[0050] In view of the problem that the dust collected by the electrostatic precipitator is directly used as raw material to participate in sintering again in the prior art, which will affect the quality of the sintered ore, the present invention also provides a dust classification and processing device to process the dust collected by the electric zone ash hopper and the bag zone ash hopper of the dust collector. In the present invention, the device also includes an additive scraper conveyor, a detection and material distribution device, and a mixing device arranged in sequence downstream of the bag zone ash hopper. Among them, the additive scraper conveyor is used to transport the small particle dust captured in the bag zone ash hopper to the detection and material distribution device. Since the small particle dust captured in the bag zone ash hopper contains not only dust particles in the flue gas, but also other substances such as additives sprayed in the transition zone, the detection and material distribution device performs component detection on the small particle dust. When it is detected that the content of additives in the dust exceeds 40% (preferably exceeds 50%), the detection and material distribution device transports the dust containing additives to the spraying device in the transition zone through the additive replenishment pipeline and the additive delivery pipeline, wherein the additive replenishment pipeline and the additive delivery pipeline are both provided with a delivery pump. On the contrary, when it is detected that the content of additives in the dust is reduced to a certain extent, the detection and distribution device distributes the dust to the mixing device. In order to facilitate the storage and transfer of small-particle dust, the present invention also sets a circulation bin and a first crushing device between the additive scraper conveyor and the detection and distribution device. At this time, the additive scraper conveyor first transports the small-particle dust captured in the bag area hopper to the circulation bin. Since these dust particles are fine and contain a small amount of moisture, they are easy to agglomerate after being accumulated in the circulation bin for a long time, so a first crushing device is added to crush the agglomerated dust and then transport it to the detection and distribution device. The present invention classifies and processes the small-particle dust according to the component content of each substance in the small-particle dust in the bag area ash hopper, and adds an additive replenishing pipeline on the basis of setting an additive bin, so as to recycle the dust removal ash (i.e., small-particle dust) containing additives collected in the bag area ash hopper, thereby making full use of resources and greatly improving the utilization rate. After multiple cycles, when the content of additives in the dust is reduced to a certain level, the dust in the circulation bin is discharged for circulation and enters other subsequent treatment processes, thereby ensuring the effectiveness of the additives and maximizing the utilization of the dust.

[0051] Similarly, the present invention provides a sintering ash scraper conveyor below the discharge port of the ash hopper of the power zone. The discharge end of the sintering ash scraper conveyor is connected to the feed port of the mixing device. That is, the sintering ash scraper conveyor is used to transport the medium and large particles of dust captured in the ash hopper of the power zone to the mixing device. In order to facilitate the storage and transfer of medium and large particles of dust, the present invention also provides a sintering dust bin and a second crushing device (such as a fine crushing device) between the sintering ash scraper conveyor and the mixing device. At this time, the sintering ash scraper conveyor first transports the medium and large particles of dust captured in the ash hopper of the power zone to the sintering dust bin. Since these dust particles are relatively large, a second crushing device is added to finely crush the medium and large particles of dust, and then transport them to the mixing device. Obviously, after the small particles of dust collected by the bag zone ash hopper are classified and processed through component detection, the present invention finally mixes the dust collected in the power zone, transition zone and bag zone in the dust collector together for processing, which saves costs and improves resource utilization.

[0052] In the present invention, the sintering machine head flue gas treatment device also includes a dissolving and washing device and a filtering device arranged in sequence downstream of the mixing device, and a drying device, a third crushing device, and a sintering batching system arranged in sequence downstream of the solid outlet of the filtering device, as well as a purification and impurity removal device, an extraction device, and a valuable metal recovery device arranged in sequence downstream of the liquid outlet of the filtering device. The medium and large particles of dust from the sintering dust bin and the small particles of dust from the circulation bin are mixed in the mixing device, and then dissolved and washed and filtered to obtain filter cakes and filtrates. Among them, the filtrate is purified, impurities removed, and extracted to obtain valuable metals. In addition, part of the filtrate can be circulated to the dissolving and washing device to participate in the dissolving and washing of dust. The filter cake is dried and crushed to obtain an iron-containing powder with low impurity content and high iron grade, and the iron-containing powder enters the sintering batching system to participate in the sintering batching. The present invention finally mixes the dust collected by the electric zone, transition zone and bag zone of the dust collector for treatment. After classification and grading, not only valuable metals are obtained, but also iron-containing powder with low impurity content and high iron grade is obtained. These powders continue to participate in sintering ingredients and finally go to sintering to improve the quality of sintered ore, solving the problem in the prior art that the dust collected by the dust collector is directly used as raw material to participate in sintering ingredients again, which will affect the quality of sintered ore and reduce the amount of qualified products. In this way, dust at all levels can be maximized, saving costs and greatly improving resource utilization.

[0053] As a preferred embodiment, the present invention provides a double-layer ash unloading valve below the discharge port of the power zone ash hopper and the bag zone ash hopper. An upper level meter is provided on the upper part of the side wall of the power zone ash hopper and the bag zone ash hopper, and a lower level meter is provided on the lower part of the side wall. Among them, the double-layer ash unloading valve controls the unloading and stopping of dust in the dust collector ash hopper (including the power zone ash hopper and the bag zone ash hopper). The upper level meter controls the time node when the double-layer ash unloading valve opens to unload ash, and the lower level meter controls the time node when the double-layer ash unloading valve stops unloading ash, and the ash unloading automation level is high. In addition, in order to prevent dust from blocking the outlet, a vibration device is provided at the discharge port of the power zone ash hopper and the bag zone ash hopper, that is, the vibration device is turned on when the dust is unloaded. A heating device is also provided in the power zone ash hopper and the bag zone ash hopper. A temperature detection device is also provided on the side wall of the power zone ash hopper and the bag zone ash hopper. The temperature detection device detects the dust temperature in the dust collector hopper. When the dust temperature is low (for example, the dust temperature is lower than 55°C), the heating device is turned on to heat the dust to prevent moisture in the dust from condensing and hardening, thereby ensuring that the shape and properties of the dust are more stable.

[0054] Based on the above-mentioned sintering machine head flue gas treatment device, the present invention also proposes a sintering machine head flue gas treatment method. In this method, the sintering machine head flue gas is sequentially passed through the electric zone, transition zone and bag zone in the dust collector for dust removal treatment, and the flue gas after dust removal treatment is then discharged after being treated by the desulfurization and denitrification device, and the dust collected by the electric zone ash hopper and the bag zone ash hopper of the dust collector undergo subsequent classification and grading treatment, which can supplement the required additives in the transition zone on the one hand, and obtain valuable metals and high-grade iron-containing powder at the same time. For example, the number of electric fields in the electric zone of the dust collector is set to 3, and the number of sub-bag zones in the bag zone of the dust collector is also set to 3, that is, the method of the present invention mainly includes the following steps:

[0055] 1) The flue gas from the sintering machine head is connected to the dust collector inlet. The flue gas first enters the dust collector bell mouth at the front end of the dust collector. After the dust collector bell mouth is dispersed by multiple air flow distribution plates, the flue gas can be evenly dispersed and enter the dust collector electrical area.

[0056] 2) The flue gas first enters the first electric field in the electric zone. The electric field strength of the first electric field is the lowest. At this time, large dust particles are charged in this area. At the same time, due to the low wind speed in this area, the dust passes slowly, and large dust particles settle in this area and fall into the ash hopper of the electric zone below. The flue gas then enters the second electric field and the third electric field of the dust collector electric zone in a uniform and dispersed manner. The medium dust particles are charged in this area in turn, and then settle into the ash hopper of the electric zone below.

[0057] 3) After the flue gas passes through the electric zone, medium and large dust particles are captured, and the flue gas after removing the medium and large dust particles enters the transition zone of the dust collector. In the transition zone, the spraying device sprays additives of specific particle size (for example, particles with a diameter of 1 to 3.5 μm, preferably 1.5 to 2 μm) into the flue gas. The additive is preferably CaCO3 with a fine porous structure. The added additive can react with SO2 in the flue gas under the environment where the flue gas contains water vapor to form a small amount of desulfurization by-products, that is, SO2 is adsorbed in the porous structure of CaCO3 and reacts with it to form new compounds and enriched in the pores of CaCO3 or on its surface, and then enters the bag area of ​​the dust collector and falls into the ash hopper of the bag area of ​​the dust collector. The remaining additives enter the bag area of ​​the dust collector together with the flue gas. The additives form a coating on the filter bag in the bag area, covering the surface of the filter bag to protect the filter bag and prevent sharp dust particles from wearing the filter bag. Although the additives are adsorbed on the surface of the filter bags, these additives and the filter bags are not tightly adhered. The small particles of dust with high resistivity and fine particle size in the flue gas are adsorbed on the surface of the filter bags covered with the additives. When the dust covering the filter bags reaches a certain thickness, the filter bags in the bag area of ​​the dust collector begin to be cleaned. In this way, the dust on the filter bags can be easily cleaned off and fall into the ash hopper in the bag area, making the cleaning of the filter bags more thorough.

[0058] 4) Since filter bags are arranged in each sub-bag area, the mesh size of the filter bags in the first sub-bag area is smaller than that in the second sub-bag area, and the mesh size of the filter bags in the second sub-bag area is smaller than that in the third sub-bag area. After the flue gas passes through the first sub-bag area, the second sub-bag area and the third sub-bag area for dust removal in turn, the dust content is greatly reduced, and then the flue gas is discharged from the outlet of the dust collector under the action of the negative pressure of the fan, and then enters the desulfurization and denitrification device through the air duct and the fan for desulfurization and denitrification, and the flue gas that meets the standards is discharged externally.

[0059] 5) When the upper level meter of the ash hopper in the electric zone of the dust collector detects that the dust in the ash hopper is full, the double-layer ash discharge valve under the ash hopper in the electric zone of the dust collector is controlled to discharge the dust into the sintering ash scraper conveyor. At the same time, the vibration device at the bottom outlet of the ash hopper starts to vibrate to prevent the dust from blocking the outlet. The sintering ash scraper conveyor then transports the dust to the sintering dust bin. When the lower level meter of the ash hopper in the electric zone of the dust collector detects that there is insufficient dust in the ash hopper, the double-layer ash discharge valve under the ash hopper in the electric zone of the dust collector is controlled to stop discharging the dust. When the temperature detection device of the ash hopper in the electric zone of the dust collector detects that the temperature in the ash hopper is low (for example, the dust temperature is lower than 55°C), the heating device of the ash hopper in the electric zone of the dust collector starts to heat the dust in the ash hopper to prevent the moisture in the dust from condensing and hardening. Since the dust in the sintering dust bin is medium and large particles, the medium and large particles in the sintering dust bin are further crushed by the fine crushing device (i.e., the second crushing device) and then transported to the mixing device.

[0060] 6) When the upper level meter of the ash hopper in the bag area of ​​the dust collector detects that the dust in the ash hopper is full, the double-layer ash discharge valve under the ash hopper in the bag area of ​​the dust collector is controlled to discharge the dust into the additive ash scraper conveyor. At the same time, the vibration device at the bottom outlet of the ash hopper starts to vibrate to prevent the dust from blocking the outlet. The additive scraper conveyor then transports the dust to the circulation bin. When the lower level meter of the ash hopper in the bag area of ​​the dust collector detects that there is insufficient dust in the ash hopper, the double-layer ash discharge valve under the ash hopper in the bag area of ​​the dust collector is controlled to stop discharging the dust. When the temperature detection device of the ash hopper in the bag area of ​​the dust collector detects that the temperature in the ash hopper is low (for example, the dust temperature is lower than 55°C), the heating device of the ash hopper in the bag area of ​​the dust collector starts to heat the dust in the ash hopper to prevent the moisture in the dust from condensing and hardening. Since the dust in the circulation bin is small-particle dust and contains a small amount of moisture, it is easy to agglomerate after being accumulated for a long time. Therefore, it is crushed by the first crushing device and then transported to the mixing device.

[0061] 7) The mixing device mixes the medium and large dust particles from the sintering dust bin and the small dust particles from the circulation bin, and then passes them into the dissolving and washing device, and dilute hydrochloric acid and water are added to the dissolving and washing device to dissolve the dust. After dissolving and washing, the dust is filtered in the filtering device to obtain filter cake and filtrate.

[0062] 8) Part of the filtrate is returned to continue to participate in the dissolution and washing, and the remaining filtrate is passed into the purification and impurity removal device for purification and impurity removal, and then extracted by the extraction device to obtain valuable metals.

[0063] 9) The filter cake is first dried by a drying device, and then crushed by a third crushing device to obtain iron-containing powder with low impurity content and high iron grade. These powders continue to participate in sintering ingredients, and finally sintered to finally obtain sintered ore.

[0064] As a preferred solution, step 6) also includes the step of detecting and sorting the dust after the first crushing device is crushed, specifically: first, the dust after the first crushing device is crushed is transported to the detection and sorting device. The detection and sorting device detects the dust composition. When it is detected that the content of additives in the dust is high (for example, more than 50%), the detection and sorting device will sort the dust containing additives into the additive replenishing pipeline, and transport it to the spraying device in the transition zone of the dust collector. The spraying device sprays the dust containing additives into the transition zone of the dust collector to react with the flue gas. When the content of additives in the dust is low (for example, less than or equal to 50%) after multiple cycles, the detection and sorting device will then sort the dust into the mixing device. At this time, the new additives are transported from the additive bin to the spraying device in the transition zone of the dust collector through the additive delivery pipeline. The spraying device then sprays the new additives into the transition zone of the dust collector to react with the flue gas, so as to recycle and treat the dust in the flue gas.

[0065] Compared with the prior art, the present invention has the following beneficial technical effects:

[0066] 1. The dust collector of the present invention is provided with an electric zone, a transition zone, and a bag zone in sequence. The electric field strength in the electric zone and the mesh diameter of the filter bag in the bag zone show a trend of strong and weak changes, which can effectively capture the dust of each level in the flue gas of the sintering machine head in a targeted manner, thereby greatly reducing the dust content in the flue gas of the sintering machine head. Through experimental research, the application can reduce the dust content of the flue gas of the sintering machine head to 10mg / Nm 3 ; Specific additives are sprayed in the transition zone to treat the flue gas, which can further improve the dust removal effect and absorb SO2 in the flue gas to reduce the processing load of subsequent flue gas purification facilities, achieve ultra-low emission standards, and have good economic benefits.

[0067] 2. The dust collector of the present invention is provided with an additive adding process in the transition zone, and a new additive adding system and a recycling system. By selecting a specific additive to treat the flue gas from the sintering machine head, the emission concentration of the flue gas dust after purification is much lower than that of the conventional head electrostatic precipitator. The use of additives can also reduce the emission concentration of part of SO2, reduce the wear of the bag filter bag, reduce the maintenance frequency of the bag filter bag, and extend the service life.

[0068] 3. The present invention classifies and processes the small-particle dust according to the component content of each substance in the small-particle dust in the bag area ash hopper, and adds an additive replenishing pipeline on the basis of setting up an additive bin, so as to recycle the dust removal ash (i.e., small-particle dust) containing additives collected in the bag area ash hopper, so as to make full use of resources and greatly improve the utilization rate. After multiple cycles, when the content of additives in the dust is reduced to a certain level, the dust in the circulation bin is discharged and circulated to enter other subsequent processing steps, thereby ensuring the effectiveness of the additives and maximizing the utilization of the dust.

[0069] 4. The present invention finally mixes the dust collected from the electric zone, transition zone and bag zone of the dust collector together for treatment. After classification and grading, not only valuable metals are obtained, but also iron-containing powder with low impurity content and high iron grade is obtained. These powders continue to participate in sintering ingredients and finally go to sintering to improve the quality of sintered ore, solving the problem in the prior art that the dust collected by the dust collector is directly used as raw material to participate in sintering ingredients again, which will affect the quality of sintered ore and reduce the amount of qualified products. In this way, dust at all levels can be maximized, saving costs and greatly improving resource utilization.

[0070] 5. A plurality of air flow distribution plates are arranged in the bell mouth of the dust collector of the present invention, and the sizes of the plurality of air flow distribution plates increase successively with the widening of the bell mouth of the dust collector until they are consistent with the size of the electric field area of ​​the dust collector; moreover, according to the flow law of the flue gas, the present invention arranges the smallest-sized and largest number of openings in the middle of the air flow distribution plate, and then the sizes of the openings gradually increase from the middle to the upper and lower sides, while the number of the openings gradually decreases. Such a distribution of large and small holes can disperse the flue gas more evenly, and cooperate with the subsequent strong and weak electric fields to efficiently capture large particles of dust. At the same time, the flue gas flow rate is smooth, the pressure is stable, and the dust removal efficiency is higher.

[0071] 6. The present invention organically combines and unifies the sintering machine head flue gas treatment and dust classification and treatment to form a complete system. The process is energy-saving and environmentally friendly, with a high resource recovery rate, ultra-low emissions, and excellent engineering economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0072] Figure 1 It is a structural schematic diagram of a sintering machine head flue gas treatment device in the prior art;

[0073] Figure 2 It is a structural schematic diagram of a sintering machine head flue gas treatment device of the present invention;

[0074] Figure 3 The present invention is a schematic diagram of the structure of a flue gas treatment device including a sintering batching system and a valuable metal recovery device;

[0075] Figure 4 It is a structural schematic diagram of the air flow distribution plate in the present invention;

[0076] Figure 5 The present invention is a flow chart of a sintering machine head flue gas treatment method.

[0077] Reference numerals:

[0078] 1: dust collector; 2: desulfurization and denitrification device; 3: fan; 4: electric zone; 401: electric field; 5: transition zone; 501: spraying device; 6: bag zone; 601: sub-bag zone; 602: filter bag; 7: dust collector bell mouth; 701: air flow distribution plate; 702: opening; 8: additive bin; 9: ash hopper in the electric zone; 10: ash hopper in the bag zone; 11: additive scraper conveyor; 12: detection and material distribution device; 13: mixing device; 14: circulation bin; 1501: first crushing device ; 1502: second crushing device; 1503: third crushing device; 16: sintering ash scraper conveyor; 17: sintering dust bin; 18: dissolving and washing device; 19: filtering device; 20: drying device; 21: sintering batching system; 22: purification and impurity removal device; 23: extraction device; 24: valuable metal recovery device; 25: double-layer ash discharge valve; 26: vibration device; 27: heating device; 2801: upper material level meter; 2802: lower material level meter; 29: temperature detection device;

[0079] L1: air duct; L2: nitrogen delivery pipeline; L3: additive delivery pipeline; L4: additive replenishing pipeline. DETAILED DESCRIPTION

[0080] The technical solution of the present invention is illustrated below by way of example, and the scope of protection requested by the present invention includes but is not limited to the following embodiments.

[0081] According to a first embodiment of the present invention, a sintering machine head fume treatment device is provided.

[0082] A sintering machine head flue gas treatment device, the device comprises a dust collector 1 and a desulfurization and denitration device 2. The flue gas outlet of the dust collector 1 is connected to the desulfurization and denitration device 2 via an air duct L1. A fan 3 is provided on the air duct L1. According to the direction of the flue gas, an electric zone 4, a transition zone 5, and a bag zone 6 are sequentially provided in the dust collector 1. A dust collector ash hopper is provided below the electric zone 4 and the bag zone 6.

[0083] In the present invention, the dust collector 1 further comprises a dust collector bell mouth 7 arranged at the flue gas inlet. The large opening end of the dust collector bell mouth 7 is connected to the electric zone 4. Preferably, an airflow distribution plate 701 is arranged in the dust collector bell mouth 7. Preferably, the number of the airflow distribution plates 701 is multiple. According to the direction of the flue gas, the size of each airflow distribution plate 701 increases successively as the dust collector bell mouth 7 widens.

[0084] Preferably, along the height direction of the dust collector 1, the airflow distribution plate 701 is provided with multiple rows of openings 702. Among them, along the middle of the airflow distribution plate 701 to the upper and lower sides, the diameter of each row of openings 702 increases successively, and the number of each row of openings 702 decreases successively.

[0085] In the present invention, a spraying device 501 is provided in the transition zone 5 . The spraying device 501 is arranged at the top and the bottom of the transition zone 5 , and the nozzle of the spraying device 501 faces the center of the transition zone 5 .

[0086] Preferably, the device further comprises an additive tank 8 and a nitrogen delivery pipeline L2. The additive tank 8 is connected to the spraying device 501 via an additive delivery pipeline L3. The nitrogen delivery pipeline L2 is also connected to the spraying device 501.

[0087] In the present invention, m electric fields 401 are provided in the electric zone 4. The strength of each electric field 401 increases in sequence according to the direction of the flue gas. An electric zone ash hopper 9 is provided below each electric field 401. Among them, m is 1 to 8, preferably 2 to 4.

[0088] In the present invention, n sub-bag areas 601 are provided in the bag area 6. Filter bags 602 are provided between adjacent sub-bag areas 601. The filter bags 602 are provided with evenly distributed mesh holes. According to the direction of the smoke, the diameter of the mesh holes on each filter bag 602 increases successively. Among them, n is 1 to 8, preferably 2 to 4. A bag area ash hopper 10 is provided below each sub-bag area 601.

[0089] In the present invention, the device further comprises an additive scraper conveyor 11, a detection and material distribution device 12, and a mixing device 13 arranged downstream of the bag area ash hopper 10. The additive scraper conveyor 11 is arranged below the discharge port of the bag area ash hopper 10. The discharge end of the additive scraper conveyor 11 is connected to the feed port of the detection and material distribution device 12. The first discharge port of the detection and material distribution device 12 is connected to the additive delivery pipeline L3 via the additive replenishment pipeline L4. The second discharge port of the detection and material distribution device 12 is connected to the feed port of the mixing device 13.

[0090] Preferably, the device further comprises a circulation bin 14 and a first crushing device 1501, which are arranged between the additive scraper conveyor 11 and the detection and material distribution device 12. The discharge end of the additive scraper conveyor 11 is connected to the feed port of the circulation bin 14. The discharge port of the circulation bin 14 is connected to the feed port of the first crushing device 1501. The discharge port of the first crushing device 1501 is connected to the feed port of the detection and material distribution device 12.

[0091] In the present invention, a sintered ash scraper conveyor 16 is provided below the discharge port of the electric zone ash hopper 9. The discharge end of the sintered ash scraper conveyor 16 is connected to the feed port of the mixing device 13.

[0092] Preferably, the device further comprises a sintering dust bin 17 and a second crushing device 1502 arranged between the sintering ash scraper conveyor 16 and the mixing device 13. The discharge end of the sintering ash scraper conveyor 16 is connected to the feed port of the sintering dust bin 17. The discharge port of the sintering dust bin 17 is connected to the feed port of the second crushing device 1502. The discharge port of the second crushing device 1502 is connected to the feed port of the mixing device 13.

[0093] In the present invention, the device further comprises a dissolving and washing device 18, a filtering device 19, a drying device 20, a third crushing device 1503, and a sintering batching system 21. The discharge port of the mixing device 13 is connected to the feed port of the dissolving and washing device 18. The discharge port of the dissolving and washing device 18 is connected to the feed port of the filtering device 19. The solid outlet of the filtering device 19 is connected to the feed port of the drying device 20. The discharge port of the drying device 20 is connected to the feed port of the third crushing device 1503. The discharge port of the third crushing device 1503 is connected to the sintering batching system 21.

[0094] Preferably, the device further comprises a purification and impurity removal device 22, an extraction device 23, and a valuable metal recovery device 24. The liquid outlet of the filter device 19 is connected to the inlet of the purification and impurity removal device 22. The outlet of the purification and impurity removal device 22 is connected to the inlet of the extraction device 23. The outlet of the extraction device 23 is connected to the valuable metal recovery device 24. Preferably, the liquid outlet of the filter device 19 is connected to the liquid inlet of the washing device 18.

[0095] In the present invention, a double-layer ash discharge valve 25 is provided below the discharge port of the power zone ash hopper 9 and the bag zone ash hopper 10. A vibration device 26 is provided at the discharge port of the power zone ash hopper 9 and the bag zone ash hopper 10. Preferably, a heating device 27 is also provided in the power zone ash hopper 9 and the bag zone ash hopper 10.

[0096] Preferably, the upper part of the side wall of the power zone ash hopper 9 and the bag zone ash hopper 10 is provided with an upper material level meter 2801, and the lower part of the side wall is provided with a lower material level meter 2802. Preferably, the side wall of the power zone ash hopper 9 and the bag zone ash hopper 10 is also provided with a temperature detection device 29.

[0097] Example 1

[0098] like Figure 2 As shown, a sintering machine head flue gas treatment device includes a dust collector 1 and a desulfurization and denitration device 2. The flue gas outlet of the dust collector 1 is connected to the desulfurization and denitration device 2 via an air duct L1. A fan 3 is provided on the air duct L1. According to the direction of the flue gas, an electric zone 4, a transition zone 5, and a bag zone 6 are sequentially provided in the dust collector 1. A dust collector ash hopper is provided below the electric zone 4 and the bag zone 6.

[0099] Example 2

[0100] Example 1 is repeated, except that the dust collector 1 further comprises a dust collector bell mouth 7 arranged at the flue gas inlet. The large opening end of the dust collector bell mouth 7 is connected to the electric zone 4. A plurality of airflow distribution plates 701 are arranged in the dust collector bell mouth 7. According to the direction of the flue gas, the size of each airflow distribution plate 701 increases successively as the dust collector bell mouth 7 widens.

[0101] Example 3

[0102] like Figure 4 As shown, Example 2 is repeated, except that multiple rows of openings 702 are provided on the airflow distribution plate 701 along the height direction of the dust collector 1. Among them, along the direction from the middle of the airflow distribution plate 701 to the upper and lower sides, the diameter of each row of openings 702 increases successively, and the number of each row of openings 702 decreases successively.

[0103] Example 4

[0104] Example 3 is repeated, except that a spraying device 501 is provided in the transition zone 5. The spraying device 501 is provided at the top and the bottom of the transition zone 5, and the nozzle of the spraying device 501 faces the center of the transition zone 5.

[0105] Example 5

[0106] Example 4 is repeated, except that the device further includes an additive tank 8 and a nitrogen delivery pipeline L2. The additive tank 8 is connected to the spraying device 501 through the additive delivery pipeline L3. The nitrogen delivery pipeline L2 is also connected to the spraying device 501.

[0107] Example 6

[0108] Repeat Example 5, except that three electric fields 401 are provided in the electric zone 4. According to the direction of the flue gas, there are the first electric field, the second electric field, and the third electric field. The intensity of each electric field 401 increases in sequence, that is, the intensity of the first electric field < the intensity of the second electric field < the intensity of the third electric field. An electric zone ash hopper 9 is provided below each electric field 401.

[0109] Example 7

[0110] Repeat Example 6, except that three sub-bag areas 601 are provided in the bag area 6. Filter bags 602 are provided between adjacent sub-bag areas 601. The filter bags 602 are provided with evenly distributed mesh holes. That is, according to the direction of the smoke, the first filter bag, the second filter bag, and the third filter bag are provided in sequence. Among them, the diameter of the mesh holes on each filter bag 602 increases in sequence, that is, the mesh diameter on the first filter bag is less than the mesh diameter on the second filter bag, and the mesh diameter on the third filter bag is less than the mesh diameter on the third filter bag. A bag area ash hopper 10 is provided below each sub-bag area 601.

[0111] Example 8

[0112] like Figure 3As shown, Example 7 is repeated, except that the device also includes an additive scraper conveyor 11, a detection and distribution device 12, and a mixing device 13 arranged downstream of the bag area ash hopper 10. Among them, the additive scraper conveyor 11 is arranged below the discharge port of the bag area ash hopper 10. The discharge end of the additive scraper conveyor 11 is connected to the feed port of the detection and distribution device 12. The first discharge port of the detection and distribution device 12 is connected to the additive conveying pipeline L3 via the additive replenishment pipeline L4. The second discharge port of the detection and distribution device 12 is connected to the feed port of the mixing device 13.

[0113] Example 9

[0114] Example 8 is repeated, except that the device further includes a circulation bin 14 and a first crushing device 1501 disposed between the additive scraper conveyor 11 and the detection and material distribution device 12. The discharge end of the additive scraper conveyor 11 is connected to the feed port of the circulation bin 14. The discharge port of the circulation bin 14 is connected to the feed port of the first crushing device 1501. The discharge port of the first crushing device 1501 is connected to the feed port of the detection and material distribution device 12.

[0115] Example 10

[0116] Example 9 is repeated, except that a sintered ash scraper conveyor 16 is provided below the discharge port of the power zone ash hopper 9. The discharge end of the sintered ash scraper conveyor 16 is connected to the feed port of the mixing device 13.

[0117] Embodiment 11

[0118] Example 10 is repeated, except that the device further includes a sintering dust bin 17 and a second crushing device 1502 disposed between the sintering ash scraper conveyor 16 and the mixing device 13. The discharge end of the sintering ash scraper conveyor 16 is connected to the feed port of the sintering dust bin 17. The discharge port of the sintering dust bin 17 is connected to the feed port of the second crushing device 1502. The discharge port of the second crushing device 1502 is connected to the feed port of the mixing device 13.

[0119] Example 12

[0120] Example 11 is repeated, except that the device further includes a dissolving and washing device 18, a filtering device 19, a drying device 20, a third crushing device 1503, and a sintering batching system 21. The discharge port of the mixing device 13 is connected to the feed port of the dissolving and washing device 18. The discharge port of the dissolving and washing device 18 is connected to the feed port of the filtering device 19. The solid outlet of the filtering device 19 is connected to the feed port of the drying device 20. The discharge port of the drying device 20 is connected to the feed port of the third crushing device 1503. The discharge port of the third crushing device 1503 is connected to the sintering batching system 21.

[0121] Embodiment 13

[0122] Example 12 is repeated, except that the device further comprises a purification and impurity removal device 22, an extraction device 23, and a valuable metal recovery device 24. The liquid outlet of the filtration device 19 is connected to the inlet of the purification and impurity removal device 22. The outlet of the purification and impurity removal device 22 is connected to the inlet of the extraction device 23. The outlet of the extraction device 23 is connected to the valuable metal recovery device 24.

[0123] Embodiment 14

[0124] Example 13 is repeated, except that the liquid outlet of the filtering device 19 is connected to the liquid inlet of the washing device 18.

[0125] Embodiment 15

[0126] Example 14 is repeated, except that a double-layer ash discharge valve 25 is provided below the discharge port of the power zone ash hopper 9 and the bag zone ash hopper 10. A vibration device 26 is provided at the discharge port of the power zone ash hopper 9 and the bag zone ash hopper 10.

[0127] Example 16

[0128] Example 15 is repeated, except that a heating device 27 is further provided in the power zone ash hopper 9 and the bag zone ash hopper 10.

[0129] Embodiment 17

[0130] Example 16 is repeated, except that an upper material level meter 2801 is provided on the upper part of the side wall of the power zone ash hopper 9 and the bag zone ash hopper 10, and a lower material level meter 2802 is provided on the lower part of the side wall.

[0131] Embodiment 18

[0132] Example 17 is repeated, except that a temperature detection device 29 is further provided on the side walls of the power zone ash hopper 9 and the bag zone ash hopper 10.

[0133] Embodiment 19

[0134] A method for treating flue gas from a sintering machine head, using the device described in Example 7, the method comprising the following steps:

[0135] 1) The smoke from the sintering machine head is connected to the smoke inlet of the dust collector 1. The smoke is first dispersed by the airflow distribution plate 701 arranged at the bell mouth 7 of the dust collector, and then the smoke enters the electric zone 4 in a uniform and dispersed manner.

[0136] 2) The flue gas passes through the electric fields 401 in the electric zone 4 in turn. As the electric field strength increases, the large and medium dust particles in the flue gas settle into the electric zone ash hopper 9 below each electric field 401 after being charged. The flue gas after removing the medium and large dust particles enters the transition zone 5.

[0137] 3) In the transition zone 5, the spraying device 501 sprays the additive into the flue gas, and the additive enters the bag zone 6 together with the flue gas. The additive forms a coating on the filter bag 602 of the bag zone 6. The small particles of dust in the flue gas are adsorbed on the surface of the filter bag 602 covered with the additive. As the thickness of the small particles of dust covering the filter bag 602 increases, the filter bag 602 begins to be cleaned, and the small particles of dust are cleaned and fall into the bag zone ash hopper 10 below each sub-bag zone 601.

[0138] 4) The dust-removed flue gas enters the desulfurization and denitrification device 2 under the action of the fan 3, and the flue gas is discharged after being desulfurized and denitrified.

[0139] Embodiment 20

[0140] like Figure 5 As shown, a method for treating flue gas from a sintering machine head, using the device described in Example 18, the method comprises the following steps:

[0141] 1) The smoke from the sintering machine head is connected to the smoke inlet of the dust collector 1. The smoke is first dispersed by the airflow distribution plate 701 arranged at the bell mouth 7 of the dust collector, and then the smoke enters the electric zone 4 in a uniform and dispersed manner.

[0142] 2) The flue gas passes through the electric fields 401 in the electric zone 4 in turn. As the electric field strength increases, the large and medium dust particles in the flue gas settle into the electric zone ash hopper 9 below each electric field 401 after being charged. The flue gas after removing the medium and large dust particles enters the transition zone 5.

[0143] 3) In the transition zone 5, the spraying device 501 sprays the additive into the flue gas, and the additive enters the bag zone 6 together with the flue gas. The additive forms a coating on the filter bag 602 of the bag zone 6. The small particles of dust in the flue gas are adsorbed on the surface of the filter bag 602 covered with the additive. As the thickness of the small particles of dust covered on the filter bag 602 increases, the filter bag 602 begins to be cleaned, and the small particles of dust are cleaned and fall into the bag zone ash hopper 10 below each sub-bag zone 601. The additive is calcium carbonate, and the particle size of the calcium carbonate is 2 μm.

[0144] 4) The dust-removed flue gas enters the desulfurization and denitrification device 2 under the action of the fan 3, and the flue gas is discharged after being desulfurized and denitrified.

[0145] 5) The medium and large dust particles falling into the ash hopper 9 of the electric zone in step 2) are unloaded into the sintering ash scraper conveyor 16, and the sintering ash scraper conveyor 16 then conveys the medium and large dust particles to the sintering dust bin 17. The medium and large dust particles are crushed by the second crushing device 1502 and then conveyed to the mixing device 13.

[0146] 6) The small dust particles falling into the bag area hopper 10 in step 3) are discharged into the additive scraper conveyor 11, and the additive scraper conveyor 11 then conveys the small dust particles to the circulation bin 14. The accumulated small dust particles agglomerate in the circulation bin 14, and the agglomerated dust is crushed by the first crushing device 1501 and then conveyed to the mixing device 13.

[0147] 7) The mixing device 13 mixes the dust from the sintering dust bin 17 and the circulation bin 14, and then passes it into the dissolving and washing device 18. Dilute hydrochloric acid and water are added to the dissolving and washing device 18 to dissolve and wash the mixed dust. The dissolved and washed dust is filtered in the filtering device 19 to obtain a filter cake and a filtrate.

[0148] 8) Part of the filtrate is circulated to the dissolving and washing device 18 to continue to participate in the dissolving and washing of dust, and the remaining filtrate is passed into the purification and impurity removal device 22 for purification and impurity removal, and then extracted by the extraction device 23 to obtain valuable metals.

[0149] 9) The filter cake is first dried by the drying device 20 and then crushed by the third crushing device 1503 to obtain iron-containing powder; the iron-containing powder is sent to the sintering batching system 21 to complete the sintering batching and then sintered.

[0150] Embodiment 21

[0151] Example 20 is repeated, except that step 6) also includes the step of detecting and dividing the dust after the first crushing device 1501 is crushed, specifically: first, the dust after the first crushing device 1501 is crushed is transported to the detection and dividing device 12. The detection and dividing device 12 detects the composition of the dust, and when the content of the additive in the dust exceeds 50%, the detection and dividing device 12 conveys the dust containing the additive to the spraying device 501 of the transition zone 5. On the contrary, when the content of the additive in the dust is less than or equal to 50%, the detection and dividing device 12 conveys the dust to the mixing device 13.

[0152] Embodiment 22

[0153] Example 21 was repeated, except that in step 3), the particle size of the additive calcium carbonate was 1.5 μm.

[0154] Embodiment 23

[0155] Example 21 is repeated, except that in the transition zone 5, the additive calcium carbonate sprayed by the spraying device 4 reacts with SO2 in the flue gas to form desulfurization by-products, which enter the bag area 6 and fall into the bag area ash hopper 10.

Claims

1. A sintering machine head flue gas treatment device, comprising a dust collector (1) and a desulfurization and denitration device (2); the flue gas outlet of the dust collector (1) is connected to the desulfurization and denitration device (2) via an air duct (L1); a fan (3) is provided on the air duct (L1); the characteristics are: According to the direction of the flue gas, the dust collector (1) is provided with an electric zone (4), a transition zone (5), and a bag zone (6) in sequence; and a dust collector ash hopper is provided below the electric zone (4) and the bag zone (6); The electric zone (4) is provided with m electric fields (401); the strength of each electric field (401) increases in sequence according to the direction of the flue gas; an electric zone ash hopper (9) is provided below each electric field (401); wherein m is 3 to 8; n sub-bag zones (601) are provided in the bag zone (6); filter bags (602) are provided between adjacent sub-bag zones (601); the filter bags (602) are provided with evenly distributed mesh holes; according to the direction of the flue gas, the diameter of the mesh holes on each filter bag (602) increases in sequence; wherein n is 2 to 8; a bag zone ash hopper (10) is provided below each sub-bag zone (601); The dust collector (1) further comprises a dust collector bell mouth (7) arranged at the smoke inlet; the large opening end of the dust collector bell mouth (7) is connected to the electric zone (4); an air flow distribution plate (701) is arranged in the dust collector bell mouth (7); along the height direction of the dust collector (1), the air flow distribution plate (701) is provided with a plurality of rows of openings (702); wherein, along the direction from the middle of the air flow distribution plate (701) to the upper and lower sides, the diameters of the rows of openings (702) increase successively, and the number of the rows of openings (702) decreases successively.

2. The device according to claim 1, characterized in that: There are a plurality of airflow distribution plates (701); according to the direction of the flue gas, the size of each airflow distribution plate (701) increases in sequence as the dust collector bell mouth (7) widens.

3. The device according to claim 1, characterized in that: A spraying device (501) is provided in the transition zone (5); the spraying device (501) is arranged at the top and the bottom of the transition zone (5), and the nozzle of the spraying device (501) faces the center of the transition zone (5).

4. The device according to claim 3, characterized in that: The device further comprises an additive bin (8) and a nitrogen delivery pipeline (L2); the additive bin (8) is connected to the spraying device (501) via the additive delivery pipeline (L3); the nitrogen delivery pipeline (L2) is also connected to the spraying device (501).

5. The device according to claim 1, characterized in that: m is 3 to 4; and / or n is 2~4.

6. The device according to claim 1, characterized in that: The device further comprises an additive scraper conveyor (11), a detection and material distribution device (12), and a mixing device (13) arranged downstream of the bag area ash hopper (10); wherein the additive scraper conveyor (11) is arranged below the discharge port of the bag area ash hopper (10); the discharge end of the additive scraper conveyor (11) is connected to the feed port of the detection and material distribution device (12); the first discharge port of the detection and material distribution device (12) is connected to the additive delivery pipe (L3) via an additive replenishment pipe (L4); and the second discharge port of the detection and material distribution device (12) is connected to the feed port of the mixing device (13).

7. The device according to claim 6, characterized in that: The device further comprises a circulation bin (14) and a first crushing device (1501) arranged between the additive scraper conveyor (11) and the detection and material distribution device (12); wherein the discharge end of the additive scraper conveyor (11) is connected to the feed port of the circulation bin (14); the discharge port of the circulation bin (14) is connected to the feed port of the first crushing device (1501); and the discharge port of the first crushing device (1501) is connected to the feed port of the detection and material distribution device (12).

8. The device according to claim 7, characterized in that: A sintered ash scraper conveyor (16) is provided below the discharge port of the power zone ash hopper (9); the discharge end of the sintered ash scraper conveyor (16) is connected to the feed port of the mixing device (13).

9. The device according to claim 8, characterized in that: The device also includes a sintering dust bin (17) and a second crushing device (1502) arranged between the sintering ash scraper conveyor (16) and the mixing device (13); wherein the discharge end of the sintering ash scraper conveyor (16) is connected to the feed port of the sintering dust bin (17); the discharge port of the sintering dust bin (17) is connected to the feed port of the second crushing device (1502); and the discharge port of the second crushing device (1502) is connected to the feed port of the mixing device (13).

10. The device according to claim 9, characterized in that: The device also includes a dissolving and washing device (18), a filtering device (19), a drying device (20), a third crushing device (1503), and a sintering batching system (21); the discharge port of the mixing device (13) is connected to the feed port of the dissolving and washing device (18); the discharge port of the dissolving and washing device (18) is connected to the feed port of the filtering device (19); the solid outlet of the filtering device (19) is connected to the feed port of the drying device (20); the discharge port of the drying device (20) is connected to the feed port of the third crushing device (1503); and the discharge port of the third crushing device (1503) is connected to the sintering batching system (21).

11. The device according to claim 10, characterized in that: The device also includes a purification and impurity removal device (22), an extraction device (23), and a valuable metal recovery device (24); wherein the liquid outlet of the filtering device (19) is connected to the inlet of the purification and impurity removal device (22); the outlet of the purification and impurity removal device (22) is connected to the inlet of the extraction device (23); and the outlet of the extraction device (23) is connected to the valuable metal recovery device (24).

12. The device according to claim 11, characterized in that: The liquid outlet of the filtering device (19) is connected to the liquid inlet of the washing device (18).

13. The device according to any one of claims 1 to 12, characterized in that: A double-layer ash discharge valve (25) is provided below the discharge ports of the power zone ash hopper (9) and the bag zone ash hopper (10); and a vibration device (26) is provided at the discharge ports of the power zone ash hopper (9) and the bag zone ash hopper (10).

14. The device according to claim 13, characterized in that: A heating device (27) is also provided in the electric zone ash hopper (9) and the bag zone ash hopper (10).

15. The device according to claim 13, characterized in that: An upper material level meter (2801) is provided on the upper part of the side wall of the power zone ash hopper (9) and the bag zone ash hopper (10), and a lower material level meter (2802) is provided on the lower part of the side wall.

16. The device according to claim 13, characterized in that: A temperature detection device (29) is also provided on the side walls of the power zone ash hopper (9) and the bag zone ash hopper (10).

17. A method for treating sintering machine head flue gas using the device according to any one of claims 1 to 16, the method comprising the following steps: 1) The flue gas from the sintering machine head is connected to the flue gas inlet of the dust collector (1). The flue gas is first dispersed by the air flow distribution plate (701) arranged at the bell mouth (7) of the dust collector, and then the flue gas enters the electric zone (4) in a uniform and dispersed manner; 2) The flue gas passes through the electric fields (401) in the electric zone (4) in sequence. As the electric field strength increases, the large and medium dust particles in the flue gas settle into the electric zone ash hopper (9) below each electric field (401) after being charged. The flue gas after the large and medium dust particles are removed enters the transition zone (5); 3) In the transition zone (5), the spraying device (501) sprays the additive into the flue gas, and the additive enters the bag zone (6) together with the flue gas; the additive forms a coating on the filter bag (602) in the bag zone (6); Small dust particles in the flue gas are adsorbed on the surface of the filter bag (602) covered with the additive. As the thickness of the small dust particles covering the filter bag (602) increases, the filter bag (602) starts to be cleaned, and the small dust particles are cleaned and fall into the bag area ash hopper (10) below each sub-bag area (601); 4) The dust-removed flue gas enters the desulfurization and denitrification device (2) under the action of the fan (3), and the flue gas is discharged after being desulfurized and denitrified; 5) The medium and large dust particles falling into the ash hopper (9) of the electric zone in step 2) are discharged into the sintering ash scraper conveyor (16), and the sintering ash scraper conveyor (16) then conveys the medium and large dust particles to the sintering dust bin (17); the medium and large dust particles are crushed by the second crushing device (1502) and then conveyed to the mixing device (13); 6) The small dust particles falling into the bag zone ash hopper (10) in step 3) are unloaded into the additive scraper conveyor (11), and the additive scraper conveyor (11) then conveys the small dust particles to the circulation bin (14); the accumulated small dust particles agglomerate in the circulation bin (14), and the agglomerated dust is crushed by the first crushing device (1501), and the dust crushed by the first crushing device (1501) is tested and sorted. The dust crushed by the first crushing device (1501) is first conveyed to the detection and sorting device (12); the detection and sorting device (12) detects the composition of the dust. When the content of the additive in the dust exceeds 40%, the detection and sorting device (12) conveys the dust containing the additive to the spraying device (501) of the transition zone (5); otherwise, the detection and sorting device (12) conveys the dust to the mixing device (13).

18. The method according to claim 17, characterized in that: The method further includes: 7) The mixing device (13) mixes the dust from the sintering dust bin (17) and the circulation bin (14), and then introduces the mixture into the dissolving and washing device (18); the dissolving and washing device (18) dissolves and washes the mixed dust; the dissolved and washed dust is filtered in the filtering device (19) to obtain a filter cake and a filtrate; 8) Part of the filtrate is circulated to the dissolving and washing device (18) to continue to participate in the dissolving and washing of dust, and the remaining filtrate is passed to the purification and impurity removal device (22) for purification and impurity removal, and then extracted by the extraction device (23) to obtain valuable metals; 9) The filter cake is first dried by the drying device (20) and then crushed by the third crushing device (1503) to obtain iron-containing powder; the iron-containing powder is sent to the sintering batching system (21) to complete the sintering batching and then sintered.

19. The method according to claim 17, characterized in that: In step 3), the additive is calcium carbonate; wherein the particle size of the additive is 1-3.5 μm.

20. The method according to claim 19, characterized in that: The detection and distribution device (12) detects the composition of the dust. When the content of the additive in the dust exceeds 50%, the detection and distribution device (12) transports the dust containing the additive to the spraying device (501) of the transition zone (5); otherwise, the detection and distribution device (12) transports the dust to the mixing device (13); and / or The particle size of the additive is 1.5~2μm.

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