A blast furnace slag micro-powder preparation and hot blast furnace flue gas purification treatment system

Abstract

The application discloses a blast furnace slag powder preparation and hot blast furnace flue gas purification treatment system and relates to the field of resource recycling. The blast furnace slag powder preparation and hot blast furnace flue gas purification treatment system comprises a raw material bin, a belt conveyor for conveying blast furnace water slag to the raw material bin, a vertical grinding mill for grinding the blast furnace water slag, a slag quantitative feeder for conveying materials in the raw material bin to the vertical grinding mill, a hot blast furnace flue gas pipeline for conveying flue gas of a blast furnace hot blast furnace to the vertical grinding mill, a bag-type dust collector for receiving grinding products of the vertical grinding mill, a powder bin, a micro-powder conveying device for conveying micro-powder collected by the bag-type dust collector to the powder bin, a chimney, an exhaust pipe for conveying flue gas purified by the bag-type dust collector to the chimney and an induced draft fan for pressurizing flue gas in the exhaust pipe. The blast furnace slag powder preparation and hot blast furnace flue gas purification treatment system dries slag micro-powder by using blast furnace hot blast furnace flue gas and desulfurizes hot blast furnace flue gas by using the slag micro-powder, thereby saving energy consumption and reducing carbon emission.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of resource recycling, in particular, relates to a blast furnace slag micro-powder preparation and hot blast stove flue gas purification treatment system and method. BACKGROUND

[0002] The blast furnace slag raw material has low added value and can only be stacked in the factory area to occupy land resources. Moreover, the slag will form a large amount of hardening and become waste without utilization value after long-time stacking, and is easy to pollute the environment, which brings great pressure to environmental protection. The slag micro-powder is a kind of superfine powder obtained by grinding the blast furnace water slag, has super-high activity, and can be used as a high-quality admixture of cement and concrete to improve the added value of the slag. The resource utilization of the slag meets the requirements of national resource conservation and environmental protection.

[0003] However, the pulverizing and drying hot air in the slag micro-powder processing is usually provided by a coal-fired or gas-fired heating furnace, which has high energy consumption and large CO2 emission. The secondary flue gas generated by the heating furnace needs to be further treated. Taking a 600,000-ton micro-powder process (coal-fired heating furnace) as an example, the annual coal consumption is 13455t, the energy consumption is huge, the generated CO2 is about 36300t / a, the generated SO2 is about 114t / a, the generated NOx is about 100t / a. x

[0004] The blast furnace hot blast stove flue gas has the characteristics of low pollutant emission concentration. Generally, the SO2 content is about 150mg / Nm 3 , the NO x content is about 130mg / Nm 3 , and the dust is about 10mg / Nm 3 . The regulation stipulates that the ultra-low emission index limit of the blast furnace hot blast stove is: particulate matter ≤10mg / Nm 3 , SO2≤50mg / Nm 3 , and nitrogen oxides ≤200mg / Nm 3 . That is, the SO2 in the domestic hot blast stove flue gas is generally over standard, and needs to be desulfurized. The domestic hot blast stove desulfurization started late, and the technology mainly learns from the treatment methods of coke oven, sintering, ceramic, and cement kiln flue gas. Common treatment processes include SDS dry desulfurization, fixed bed dry desulfurization, and moving bed dry desulfurization technologies. The existing desulfurization technologies mostly have high initial investment and operation cost, large by-product treatment difficulty, and large occupied area, which seriously restricts the popularization and application of the hot blast stove desulfurization technology. SUMMARY

[0005] ​The application aims to provide a blast furnace slag powder preparation and hot blast furnace flue gas purification treatment system, which uses the waste heat of blast furnace hot blast furnace flue gas to replace coal or gas heating furnace as the drying heat source for slag powder preparation, and uses calcium oxide in the slag powder to remove sulfur dioxide in the hot blast furnace flue gas, thereby saving energy consumption and reducing carbon and sulfur emissions.

[0006] The application is implemented in the following manner:

[0007] The application provides a blast furnace slag powder preparation and hot blast furnace flue gas purification treatment system, which comprises a raw material bin for storing blast furnace water slag, a belt conveyor for conveying the blast furnace water slag to the raw material bin, a vertical mill for grinding the blast furnace water slag, a slag dosing feeder for conveying the material in the raw material bin to the vertical mill, a hot blast furnace flue gas pipeline for conveying the flue gas of the blast furnace hot blast furnace to the vertical mill, a bag dust collector for receiving the grinding product of the vertical mill, a powder bin, a micro-powder conveying device for conveying the micro-powder collected by the bag dust collector to the powder bin, a chimney, an exhaust pipe for conveying the purified flue gas of the bag dust collector to the chimney, and an induced draft fan for pressurizing the flue gas in the exhaust pipe.

[0008] In some optional embodiments, a flue gas pre-treater is arranged between the vertical mill and the hot blast furnace flue gas pipeline, and a spraying device is arranged in the flue gas pre-treater.

[0009] In some optional embodiments, a lime bin, a slaked lime reactor for receiving lime in the lime bin, and a screw feeder for conveying the material in the slaked lime reactor to the feed inlet of the vertical mill are further included, and the slaked lime reactor is connected with a stirring device and a water feeding pipe.

[0010] In some optional embodiments, an air chute is connected to the bottom of the bag dust collector through a backflow pipe, the air chute is used for conveying the material in the backflow pipe to the vertical mill, and the backflow pipe is provided with a first shut-off valve.

[0011] In some optional embodiments, a baking soda bin, a baking soda mill for crushing the baking soda, a baking soda dosing feeder for conveying the material in the baking soda bin to the baking soda mill for crushing, and a conveying pipe for conveying the crushed material of the baking soda mill to the bag dust collector are further included.

[0012] In some optional embodiments, a baking soda desulfurization reactor is arranged between the baking soda mill and the conveying pipe, the hot blast furnace flue gas pipeline and the baking soda desulfurization reactor are communicated through a connecting pipe, the connecting pipe is provided with a second shut-off valve for controlling the opening and closing thereof, the flue gas pre-treater and the vertical mill are communicated through a flue gas conveying pipe provided with a third shut-off valve, and the bag dust collector is further communicated with a sodium sulfate powder bin through a recovery conveying device.

[0013] In some alternative embodiments, a coal gas preheater and an air preheater are further included, one end of the coal gas preheater and the air preheater is communicated with the flue gas preprocessor, and the other end is communicated with the blast furnace hot blast stove.

[0014] In some alternative embodiments, a heating furnace and a hot air conveying pipe communicated with the heating furnace and the flue gas conveying pipe are further included.

[0015] The blast furnace slag micro-powder preparation and hot blast stove flue gas purification treatment system provided by the application includes a raw material bin for storing blast furnace water slag, a belt conveyor for conveying the blast furnace water slag to the raw material bin, a vertical mill for grinding the blast furnace water slag, a slag quantitative feeder for conveying the material in the raw material bin to the vertical mill, a hot blast stove flue gas pipeline for conveying the flue gas of the blast furnace hot blast stove to the vertical mill, a bag-type dust collector for receiving the grinding product of the vertical mill, a powder bin, a micro-powder conveying device for conveying the micro-powder collected by the bag-type dust collector to the powder bin, a chimney, an exhaust pipe for conveying the flue gas purified by the bag-type dust collector to the chimney, and an induced draft fan for pressurizing the flue gas in the exhaust pipe. The blast furnace slag micro-powder preparation and hot blast stove flue gas purification treatment system provided by the application uses the waste heat of the blast furnace hot blast stove flue gas to replace the coal-fired or gas-fired heating furnace as the drying heat source for the preparation of the slag micro-powder, and uses the calcium oxide in the slag micro-powder to remove the sulfur dioxide in the hot blast stove flue gas, thereby saving energy consumption and reducing carbon and sulfur emissions. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some of the embodiments of the application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0017] Figure 1 The structure schematic diagram of the blast furnace slag micro-powder preparation and hot blast stove flue gas purification treatment system provided for the embodiment 1 of the application is shown in the figure;

[0018] Figure 2 The structure schematic diagram of the blast furnace slag micro-powder preparation and hot blast stove flue gas purification treatment system provided for the embodiment 2 of the application is shown in the figure;

[0019] Figure 3 The structure schematic diagram of the blast furnace slag micro-powder preparation and hot blast stove flue gas purification treatment system provided for the embodiment 3 of the application is shown in the figure;

[0020] Figure 4 The structure schematic diagram of the blast furnace slag micro-powder preparation and hot blast stove flue gas purification treatment system provided for the embodiment 4 of the application is shown in the figure.

[0021] In the figure: 100, raw material bin; 110, belt conveyor; 120, vertical mill; 130, slag feeder; 140, hot blast furnace flue; 150, bag dust collector; 160, fine ore bin; 170, fine ore conveying device; 180, chimney; 190, exhaust pipe; 200, induced draft fan; 210, flue gas pretreater; 220, spraying device; 230, lime bin; 240, slaked lime reactor; 250, screw feeder; 260, stirring device; 270, water feeding pipe; 280, backflow pipe; 290, air chute; 300, first shut-off valve; 310, baking soda bin; 320, baking soda mill; 330, baking soda feeder; 340, conveying pipe; 350, baking soda desulfurization reactor; 360, connecting pipe; 370, second shut-off valve; 380, flue gas conveying pipe; 390, third shut-off valve; 400, coal gas preheater; 410, air preheater; 420, heating furnace; 430, hot air conveying pipe; 440, recovery conveying device; 450, sodium sulfate powder bin; 500, blast furnace hot blast furnace. DETAILED DESCRIPTION

[0022] In order to make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some but not all of the embodiments of the present application. The components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations.

[0023] Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative labor are within the scope of protection of the present application.

[0024] It should be noted that: similar reference numerals and letters represent similar items in the following drawings, therefore, once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings.

[0025] In the description of the present application, it needs to be explained that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship commonly placed when the product of the application is used, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third" and the like are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0026] In addition, the terms "horizontal", "vertical", "overhanging" and the like do not mean that the components must be absolutely horizontal or overhanging, but can be slightly inclined. For example, "horizontal" only means that it is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0027] In the description of the present application, it also needs to be explained that unless otherwise explicitly specified and limited, the terms "arrangement", "installation", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0028] In the present application, unless otherwise explicitly specified and limited, the first feature "above" or "below" the second feature can include that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the first feature "above", "above" and "above" the second feature includes that the first feature is directly above and obliquely above the second feature, or only means that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "below" and "below" the second feature includes that the first feature is directly below and obliquely below the second feature, or only means that the horizontal height of the first feature is less than that of the second feature.

[0029] The features and performance of the blast furnace slag powder preparation and hot blast furnace flue gas purification treatment system of the present application are further described in detail below in conjunction with the embodiments.

[0030] Example 1

[0031] As Figure 1As shown, the application provides a blast furnace slag powder preparation and hot blast furnace flue gas purification treatment system, which comprises a raw material bin 100 for storing blast furnace water slag, a belt conveyor 110 for conveying the blast furnace water slag to the raw material bin 100, a vertical mill 120 for grinding the received blast furnace water slag, a slag quantitative feeder 130 for conveying the material in the raw material bin 100 to the vertical mill 120, a hot blast furnace flue gas pipeline 140 for conveying the hot blast furnace flue gas discharged by a blast furnace hot blast furnace 500 to the vertical mill 120, a bag dust collector 150 for receiving the grinding product of the vertical mill 120, a powder bin 160, a powder conveying device 170 for conveying the micro powder collected by the bag dust collector 150 to the powder bin 160, a chimney 180, an exhaust pipe 190 for conveying the purified flue gas of the bag dust collector 150 to the chimney 180, and an induced draft fan 200 for pressurizing the flue gas in the exhaust pipe 190. A flue gas pretreater 210 is arranged between the vertical mill 120 and the hot blast furnace flue gas pipeline 140, and a spraying device 220 is arranged in the flue gas pretreater 210. The powder conveying device 170 in the embodiment is a pneumatic conveying device. The top discharge end of the belt conveyor 110 is located above the top opening of the raw material bin 100. The inlet and outlet of the slag quantitative feeder 130 are respectively connected to the bottom outlet of the raw material bin 100 and the top inlet of the vertical mill 120. The two ends of the hot blast furnace flue gas pipeline 140 are respectively connected to the flue gas outlet of the blast furnace hot blast furnace 500 and the bottom inlet of the vertical mill 120. The top inlet of the bag dust collector 150 is connected to the top outlet of the vertical mill 120. The top inlet and the bottom outlet of the powder conveying device 170 are respectively connected to the bottom outlet of the bag dust collector 150 and the top inlet of the powder bin 160. The two ends of the exhaust pipe 190 are respectively connected to the top flue gas outlet of the bag dust collector 150 and the bottom of the chimney 180.

[0032] The working principle of the blast furnace slag powder preparation and hot blast furnace flue gas purification treatment system provided by the embodiment of the application is as follows: the blast furnace water slag with a water content of about 25% after blast furnace treatment is placed and dried in a blast furnace water slag yard and an indoor yard until the water content is reduced to 15-20%, the dried blast furnace water slag is conveyed to a raw material bin 100 by using a belt conveyor 110, the blast furnace water slag in the raw material bin 100 is conveyed to a vertical mill 120 by using a slag quantitative feeder 130 connected at the bottom, the slag is crushed in the vertical mill 120, at the same time, the hot blast furnace flue gas is conveyed into the vertical mill 120 by using a hot blast furnace flue gas pipeline 140 connected with a hot blast furnace 500, the crushed slag powder in the vertical mill 120 is dried by using the hot blast furnace flue gas, so that the water content of the slag powder in the vertical mill 120 is reduced to about 1%, finally, the slag powder with a proper particle size after crushing is discharged from the vertical mill 120 and enters a bag-type dust collector 150 connected with a discharge port of the vertical mill 120, finally, the bag-type dust collector 150 collects the slag powder, and then the slag powder is conveyed to a slag powder bin 160 by using a slag powder conveying device 170 connected with the bottom of the bag-type dust collector 150, at the same time, the flue gas filtered by the bag-type dust collector 150 is pressurized by using an induced draft fan 200 and then is discharged into a chimney 180 through a flue gas discharge pipe 190, and the dust concentration of the discharged flue gas is ≤10 mg / Nm 3 The slag powder conveying device 170 is a pneumatic conveying device.

[0033] In the embodiment, the hot blast furnace flue gas is conveyed to a flue gas pre-treater 210 for spray treatment by using the hot blast furnace flue gas pipeline 140, a spray device 220 is used to spray water mist into the flue gas pre-treater 210, the water mist reacts with SO2 in the hot blast furnace flue gas to generate H2SO3, and then the flue gas is introduced into the vertical mill 120, so that CaO in the slag powder in the vertical mill 120 fully contacts and reacts with H2SO3 in the flue gas to generate CaSO3, thereby achieving the effect of flue gas desulfurization, and ensuring that the SO2 concentration at the outlet of the chimney 180 is ≤35 mg / Nm 3 The temperature of the hot blast furnace flue gas introduced into the vertical mill 120 is 280-300°C, and the temperature of the flue gas discharged from the discharge port of the vertical mill 120 is 85-95°C.

[0034] In the embodiment, the filtering air speed of the bag-type dust collector 150 is ≤0.65 m / min, and the dust concentration of the outlet flue gas is ≤10 mg / Nm 3 , which meets the requirement of ultra-low emission.

[0035] Embodiment 2

[0036] As Figure 2As shown, the embodiment of the present application provides a blast furnace slag micro-powder preparation and hot blast furnace flue gas purification treatment system, which has substantially the same structure as the blast furnace slag micro-powder preparation and hot blast furnace flue gas purification treatment system provided in the embodiment 1, and the difference lies in that, in the embodiment, it further comprises a lime bin 230, a slaked lime reactor 240 for receiving lime in the lime bin 230, and a screw feeder 250 for conveying materials in the slaked lime reactor 240 to the feed inlet of the vertical grinding mill 120, the slaked lime reactor 240 is connected with a stirring device 260 and a water adding pipe 270; the bottom of the bag-type dust collector 150 is connected with an air chute 290 through a reflux pipe 280, the air chute 290 is used for conveying materials in the reflux pipe 280 to the vertical grinding mill 120, and the reflux pipe 280 is provided with a first shut-off valve 300; wherein the slaked lime reactor 240 is arranged below the lime bin 230 to receive lime.

[0037] The embodiment of the present application provides a blast furnace slag micro-powder preparation and hot blast furnace flue gas purification treatment system, which stores lime by arranging a lime bin 230, receives lime stored in the lime bin 230 by arranging a slaked lime reactor 240 below the lime bin 230, adds water into the slaked lime reactor 240 by arranging a water adding pipe 270, stirs and reacts to obtain slaked lime by arranging a stirring device 260, and conveys the slaked lime in the slaked lime reactor 240 into the vertical grinding mill 120 by arranging a screw feeder 250, so that the slaked lime reacts with H2SO3 in the hot blast furnace flue gas to produce CaSO3 in the vertical grinding mill 120 to achieve the effect of flue gas desulfurization, the feeding amount of the screw feeder 250 is adjusted according to the concentration of SO2 discharged from the chimney 180, and the content of SO2 in the flue gas discharged from the chimney 180 is ensured to be ≤35 mg / Nm 3 .

[0038] When the slag micro-powder is not needed to be produced, the slag quantitative feeder 130 can be controlled to stop conveying materials in the raw material bin 100 into the vertical grinding mill 120, and only the slaked lime in the slaked lime reactor 240 is conveyed into the vertical grinding mill 120 by the screw feeder 250, the input amount of the slaked lime is adjusted to ensure that the content of SO2 in the flue gas at the outlet of the chimney 180 is ≤35 mg / Nm 3 , and the dust concentration in the flue gas is ≤10 mg / Nm 3 .

[0039] When the reaction time is limited and the slaked lime cannot be completely reacted, the first shut-off valve 300 is controlled to be opened, so that part of the slaked lime collected at the bottom of the bag-type dust collector 150 is conveyed into the vertical grinding mill 120 through the reflux pipe 280 and the air chute 290 to perform desulfurization reaction, and the other part of the slaked lime is sent into the powder bin 160 by the micro-powder conveying device 170 for storage.

[0040] Embodiment 3

[0041] As Figure 3As shown, the embodiment of the present application provides a blast furnace slag powder preparation and hot blast furnace flue gas purification treatment system, which has substantially the same structure as the blast furnace slag powder preparation and hot blast furnace flue gas purification treatment system provided in embodiment 1, and the difference lies in that, in the present embodiment, it further comprises a baking soda bin 310, a baking soda grinder 320 for grinding the baking soda, a baking soda dosing machine 330 for conveying the material in the baking soda bin 310 to the baking soda grinder 320 for grinding, and a conveying pipe 340 for conveying the ground material of the baking soda grinder 320 to the bag-type dust collector 150, a baking soda desulfurization reactor 350 is arranged between the baking soda grinder 320 and the conveying pipe 340, the hot blast furnace flue gas pipeline 140 and the baking soda desulfurization reactor 350 are communicated through a connecting pipe 360, a second shut-off valve 370 for controlling the opening and closing of the connecting pipe 360 is arranged on the connecting pipe 360, and the flue gas pretreater 210 and the vertical mill 120 are communicated through a flue gas conveying pipe 380 provided with a third shut-off valve 390; the bag-type dust collector 150 is further communicated with a sodium sulfate powder bin 450 through a recycling conveying device 440, in the present embodiment, the recycling conveying device 440 is a pneumatic conveying device; wherein the inlet and outlet of the baking soda dosing machine 330 are connected with the bottom outlet of the baking soda bin 310 and the top inlet of the baking soda grinder 320 respectively, and the two ends of the conveying pipe 340 are connected with the bottom outlet of the baking soda grinder 320 and the top inlet of the bag-type dust collector 150 respectively.

[0042] The blast furnace slag powder preparation and hot blast furnace flue gas purification treatment system provided in the embodiment of the present application can ensure that the emission of the hot blast furnace flue gas meets the standard when the vertical mill 120 fails or is in the state of maintenance and repair, at this time, the third shut-off valve 390 on the flue gas conveying pipe 380 between the flue gas pretreater 210 and the vertical mill 120 is cut off, and the second shut-off valve 370 on the connecting pipe 360 between the hot blast furnace flue gas pipeline 140 and the baking soda desulfurization reactor 350 is communicated, so that the hot blast furnace flue gas conveyed by the hot blast furnace flue gas pipeline 140 does not pass through the flue gas pretreater 210 and the vertical mill 120, but is introduced into the baking soda desulfurization reactor 350 through the connecting pipe 360, and the baking soda dosing machine 330 is used to convey the baking soda in the baking soda bin 310 to the baking soda grinder 320 for grinding, and then to the baking soda desulfurization reactor 350 for mixing reaction with the hot blast furnace flue gas, so that the baking soda and SO2 in the hot blast furnace flue gas react to generate Na2SO4, which is desulfurized, and then is conveyed to the bag-type dust collector 150 through the conveying pipe 340, the Na2SO4 is conveyed to the sodium sulfate powder bin 450 for storage through the recycling conveying device 440 connected with the bag-type dust collector 150, and the dust concentration of the flue gas filtered by the bag-type dust collector 150 is ≤10 mg / Nm 3 , the SO2 content is ≤35 mg / Nm 3 , and the flue gas is discharged by the induced draft fan 200 after being pressurized.

[0043] Embodiment 4

[0044] As Figure 4 shown, the embodiment of the present application provides a blast furnace slag powder preparation and hot blast furnace flue gas purification treatment system, which is substantially the same as the blast furnace slag powder preparation and hot blast furnace flue gas purification treatment system provided in embodiment 2, the difference is that in the present embodiment, it further comprises a coal gas preheater 400, an air preheater 410, a heating furnace 420 and a hot air conveying pipe 430 communicating the heating furnace 420 and the flue gas conveying pipe 380, one end of the coal gas preheater 400 and the air preheater 410 communicates with the flue gas pretreater 210, and the other end communicates with the blast furnace hot blast furnace 500.

[0045] The blast furnace slag powder preparation and hot blast furnace flue gas purification treatment system provided in the embodiment of the present application is provided with a coal gas preheater 400 and an air preheater 410, the hot blast furnace flue gas of 280-320℃ in the blast furnace hot blast furnace 500 is divided into two routes, one route passes through the coal gas preheater 400 to preheat the blast furnace hot blast furnace 500 with blast furnace gas to about 180℃, and the other route passes through the air preheater 410 to preheat the blast furnace hot blast furnace 500 with combustion air to about 180℃, so as to increase the temperature of the blast furnace gas and combustion air entering the blast furnace hot blast furnace 500 to increase the furnace temperature.

[0046] At the same time, the hot blast furnace flue gas reduced to 190-200℃ by the coal gas preheater 400 and the air preheater 410 is conveyed to the flue gas pretreater 210 through the hot blast furnace flue gas pipe 140, and is subjected to spray treatment by the spray device 220, so that the water mist reacts with SO2 in the hot blast furnace flue gas to generate H2SO3; at the same time, the air is heated to 600-800℃ by the heating furnace 420 and is conveyed to the flue gas conveying pipe 380 through the hot air conveying pipe 430, and is mixed with the flue gas at the outlet of the flue gas pretreater 210 to enter the vertical mill 120 to perform turbulent drying on the divided slag, and in the drying process, CaO in the slag powder fully contacts and reacts with H2SO3 in the flue gas to generate CaSO3, which plays a flue gas desulfurization effect, and ensures that the SO2 concentration at the chimney outlet is ≤35mg / Nm 3 .

[0047] In other optional embodiments, the micro-powder conveying device 170 and the recovery conveying device 440 can also be air chute hopper elevators.

[0048] The above-described embodiments are part of the embodiments of the present application, rather than all the embodiments. The detailed description of the embodiments of the present application is not intended to limit the scope of the claimed application, but only represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

Claims

1. A blast furnace slag micro-powder preparation and hot blast furnace flue gas purification treatment system, characterized in that, The application relates to a blast furnace slag powder production system, which comprises a raw material bin for storing blast furnace slag, a belt conveyor for conveying blast furnace slag to the raw material bin, a vertical mill for grinding blast furnace slag, a slag feeder for conveying materials in the raw material bin to the vertical mill, a hot blast furnace flue for conveying flue gas of a blast furnace hot blast furnace to the vertical mill, a bag-type dust collector for receiving grinding products of the vertical mill, a powder bin, a micro-powder conveying device for conveying micro-powder collected by the bag-type dust collector to the powder bin, a chimney, an exhaust pipe for conveying flue gas purified by the bag-type dust collector to the chimney, and a draft fan for pressurizing flue gas in the exhaust pipe, wherein a flue gas pre-treater is arranged between the vertical mill and the hot blast furnace flue, the flue gas pre-treater is provided with a spraying device, the system further comprises a sodium bicarbonate bin, a sodium bicarbonate grinder for grinding sodium bicarbonate, a sodium bicarbonate feeder for conveying materials in the sodium bicarbonate bin to the sodium bicarbonate grinder, and a conveying pipe for conveying grinding materials of the sodium bicarbonate grinder to the bag-type dust collector, a sodium bicarbonate desulfurization reactor is arranged between the sodium bicarbonate grinder and the conveying pipe, the hot blast furnace flue and the sodium bicarbonate desulfurization reactor are communicated through a connecting pipe, the connecting pipe is provided with a second cut-off valve for controlling opening and closing of the connecting pipe, and the flue gas pre-treater and the vertical mill are communicated through a flue gas conveying pipe provided with a third cut-off valve; the bag-type dust collector is further communicated with a sodium sulfate powder bin through a recycling conveying device; the system further comprises a lime bin, a slaked lime reactor for receiving lime in the lime bin, and a screw feeder for conveying materials in the slaked lime reactor to a feeding port of the vertical mill, and the slaked lime reactor is connected with a stirring device and a water feeding pipe.

2. The blast furnace slag micro powder preparation and hot blast furnace flue gas purification treatment system according to claim 1, characterized in that, The bottom of the bag-type dust collector is connected with an air chute through a backflow pipe, the air chute is used for conveying materials in the backflow pipe to the vertical mill, and the backflow pipe is provided with a first cut-off valve.

3. The blast furnace slag micro powder preparation and hot blast furnace flue gas purification treatment system according to claim 1, characterized in that, The system further comprises a coal gas pre-heater and an air pre-heater, one end of the coal gas pre-heater and the air pre-heater is communicated with the flue gas pre-treater, and the other end is communicated with the blast furnace hot blast furnace.

4. The blast furnace slag micro powder preparation and hot blast furnace flue gas purification treatment system according to claim 3, characterized in that, The system further comprises a heating furnace and a hot air conveying pipe communicated between the heating furnace and the flue gas conveying pipe.

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