A molten high-temperature steel slag purification treatment system and method

Abstract

The present invention relates to a system and method for purifying molten high-temperature steel slag, and relates to the field of steel slag treatment, including a cooling and crushing device, a water treatment device, a normal pressure cooling device, and a steam collection and purification device; wherein the water treatment device includes a nozzle and a sewage purification device respectively arranged in the cooling and crushing device and the normal pressure cooling device; the cooling and crushing device includes a granulation and crushing device for crushing the high-temperature steel slag, and the nozzle located in the cooling and crushing device is used for intermittent water spraying and cooling the steel slag in the granulation and crushing device; the normal pressure cooling device includes a cooling gas collection hood, and the nozzle located in the normal pressure cooling device is used for spraying water and cooling the crushed steel slag transported to the cooling gas collection hood; the steam collection and purification device is used to purify and discharge dust-containing steam. The present invention can quickly, efficiently and cleanly complete the treatment of molten high-temperature electric furnace steel slag.

Description

Technical Field

[0001] The present invention relates to the field of steel slag treatment, and in particular to a system and method for cleaning molten high-temperature steel slag. Background Art

[0002] In recent years, influenced by the national environmental protection policies such as energy conservation and emission reduction, the annual output of scrap steel in my country has also increased year by year. Under the above circumstances, short-process steelmaking processes such as electric furnace steelmaking are gradually replacing traditional converter steelmaking processes. As one of the solid wastes of steel slag, the main components of electric furnace slag are similar to those of converter slag, mainly containing dicalcium silicate, tricalcium silicate and a small amount of metallic iron. However, since the main raw materials of electric furnace steelmaking are scrap steel and a small amount of sponge iron, the slag production is small, so there is no need to add too much calcium oxide and other slag-forming agents during the steelmaking process, so that the content of free calcium oxide in electric furnace slag is low, generally not exceeding 3%. Therefore, the molten electric furnace slag does not need to be cooled by methods such as hot stuffing. At present, my country's electric furnace slag is mostly treated by extensive methods such as hot pouring. The treatment process is extensive, and a large amount of dust-containing steam generated during the treatment process is unorganized and discharged, which seriously pollutes the environment. Summary of the invention

[0003] Technical issues

[0004] In view of this, the technical problem to be solved by the present invention is how to provide a system and method for purifying molten high-temperature steel slag, so that the discharge and treatment of the steel slag can be more controllable and orderly.

[0005] Solution

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0007] The present invention provides a molten high-temperature steel slag purification system, comprising a cooling and crushing device, a water treatment device, a normal pressure cooling device and a steam collection and purification device; wherein:

[0008] The water treatment device comprises a nozzle and a sewage purification device respectively arranged in the cooling and crushing device and the normal pressure cooling device; the sewage purification device is used to process and recycle the muddy return water generated by the water spraying for recycling;

[0009] The cooling and crushing device includes a granulation and crushing device for crushing high-temperature steel slag, and a nozzle located in the cooling and crushing device is used to intermittently spray water to cool the steel slag in the granulation and crushing device;

[0010] The atmospheric pressure cooling device comprises a cooling gas collecting hood, and the nozzle located in the atmospheric pressure cooling device is used to spray water to cool the crushed steel slag transported to the cooling gas collecting hood;

[0011] The steam collecting and purifying device is respectively connected with the cooling and crushing device and the cooling and gas collecting hood through steam pipelines; the steam collecting and purifying device is used for purifying and discharging dust-containing steam.

[0012] The high temperature steel slag in the present invention may be high temperature molten electric furnace steel slag.

[0013] Furthermore, the cooling and crushing device also includes a tilting device, a slag receiving container and a slag receiving and transporting device for transporting the slag receiving container;

[0014] The tipping device is used to pour the steel slag to be processed into the granulation and crushing device;

[0015] The slag receiving container is used to receive the steel slag crushed by the granulation and crushing equipment;

[0016] The slag receiving and transferring equipment is used to transfer the slag receiving container to the atmospheric pressure cooling device.

[0017] Furthermore, the granulation and crushing equipment comprises a crushing mechanism and a traveling mechanism for driving the crushing mechanism to travel; optionally, the crushing mechanism comprises a plurality of crushing teeth.

[0018] Furthermore, the atmospheric pressure cooling device also includes a mobile transfer trolley for transporting the slag receiving container into the cooling gas collecting hood.

[0019] Furthermore, it also includes a track for the equipment to travel.

[0020] Furthermore, the sewage purification device includes a water suction well, a pump house, a sludge sedimentation facility, a sludge dewatering facility and a return well;

[0021] The return water well is used to receive muddy return water generated by the cooling and crushing device and / or the normal pressure cooling device flowing in through the pipeline;

[0022] The pump house is used to pump the muddy return water in the return well into the sludge sedimentation facility;

[0023] The sludge sedimentation facility is used for sedimentation treatment of sludge-containing return water;

[0024] The sludge dewatering facility is used to dewater the fine steel slag sludge in the water system.

[0025] The water suction well is used to suck the supernatant in the sludge sedimentation facility and realize water reuse through the pump room.

[0026] Further, the steam collection and purification device includes a dust removal fan, a primary purification device, a secondary purification device and an exhaust chimney;

[0027] The dust removal fan is used to generate negative pressure to allow dust-containing steam to enter the primary purification device and the secondary purification device.

[0028] Furthermore, the primary purification device includes a washing tower and a plurality of nozzles arranged in the washing tower, which are used to wash away the dust particles by spraying water into the dust-containing flue gas.

[0029] Furthermore, the secondary purification device includes a high-voltage electric field and a positive electrode plate. The high-voltage electric field is used to ionize dust particles in the steam to make it negatively charged, and the positive electrode plate is used to adsorb the ionized dust particles with negative charges.

[0030] On the other hand, a method for cleaning molten high-temperature steel slag is provided, comprising the following steps:

[0031] The high-temperature slag is poured into the cooling and crushing device for crushing and water spray cooling; the temperature is reduced by 500-900°C; the maximum particle size is controlled below 300mm; optionally, the dust-containing steam generated during the cooling and granulation process can be organized through the steam pipeline to enter the supporting steam collection and purification device for purification;

[0032] The steel slag crushed by the cooling and crushing device is transferred to the cooling gas collecting hood;

[0033] Spray water to cool the steel slag in the cooling gas collecting hood; optionally, the water spraying time is 1.5 to 3 hours;

[0034] The dusty steam generated in the cooling hood enters the steam collection and purification device from the top for purification; optionally, the dust concentration of the exhaust steam is much less than 10mg / m 3 .

[0035] Furthermore, the treatment method adopts the molten high-temperature steel slag purification treatment system for treatment.

[0036] Furthermore, in the cooling and crushing device, the water spray cooling operation is performed by interspersing multiple water sprays.

[0037] Preferably, the water spraying cycle is 20 to 40 minutes per cycle.

[0038] Preferably, in each cycle, the water spraying time is 8 to 20 minutes, and the water spraying volume is 25 to 45 m 3 / h.

[0039] Beneficial Effects

[0040] According to the characteristics of electric furnace steelmaking and electric furnace slag of electric power plants, and taking into account the low content of unstable substances in electric furnace slag such as free oxidation and reformation, the present invention does not need to adopt the existing relatively complicated pressure treatment process and equipment for hot stuffy stabilization treatment. Through the optimization, adjustment and reorganization of the process scheme and the use of a set of special equipment suitable for electric furnace slag treatment, the molten high-temperature electric furnace slag can be treated quickly, efficiently and cleanly, and the slag and iron in the electric furnace slag can be effectively separated, which makes the treatment process safe and reliable, and also reduces the construction and operation costs, creating certain conditions for the rapid promotion of short-process steelmaking processes such as electric furnace steelmaking and hydrogen-based smelting.

[0041] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, and to make the above and other purposes, technical features and advantages of the present invention easier to understand, one or more preferred embodiments are listed below and described in detail with the accompanying drawings as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] One or more embodiments are exemplarily described by pictures in the corresponding drawings, and these exemplified descriptions do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings represent similar elements, and unless otherwise stated, the figures in the drawings do not constitute proportional limitations.

[0043] Figure 1 This is a process plan layout diagram of an embodiment of a molten high-temperature slag purification treatment system of the present invention.

[0044] Figure 2 It is a cross-sectional view of an embodiment of the atmospheric pressure cooling device of the present invention.

[0045] Description of main reference numerals:

[0046] 1 Cooling and crushing device, 1-1 tipping equipment, 1-2 granulation and crushing equipment, 1-3 slag receiving and transferring equipment, 1-4 slag receiving container, 2 atmospheric pressure cooling device, 2-1 mobile transfer trolley, 2-2 cooling gas collecting hood, 2-3 steam pipeline, 3 water treatment device, 3-1 water suction well, 3-2 pump room, 3-3 sludge sedimentation facility, 3-4 sludge dewatering facility, 3-5 return water well, 4 steam collecting and purification device, 4-1 dust removal fan, 4-2 primary dust removal device, 4-3 secondary dust removal device, 4-4 exhaust chimney. DETAILED DESCRIPTION

[0047] The specific implementation modes of the present invention are described in detail below in conjunction with the accompanying drawings, but it should be understood that the protection scope of the present invention is not limited by the specific implementation modes.

[0048] Unless explicitly stated otherwise, throughout the specification and claims, the term “comprise” or variations such as “include” or “comprising”, etc., will be understood to include the stated elements or components but not to exclude other elements or components.

[0049] In this document, for the convenience of description, spatial relative terms such as "below", "below", "down", "above", "above", "upper", etc. may be used to describe the relationship between one element or feature and another element or feature in the accompanying drawings. It should be understood that the spatial relative terms are intended to include different orientations of the object in use or operation in addition to the orientation depicted in the figure. For example, if the object in the figure is turned over, the element described as being "below" or "below" other elements or features will be oriented "above" the element or feature. Therefore, the exemplary term "below" can include both below and above. Objects may also have other orientations (rotated 90 degrees or other orientations) and the spatial relative terms used in this document should be interpreted accordingly.

[0050] In this document, the terms "first", "second", etc. are used to distinguish two different elements or parts, and are not used to limit a specific position or relative relationship. In other words, in some embodiments, the terms "first", "second", etc. can also be interchangeable.

[0051] like Figure 1 to Figure 2 As shown, the present invention provides a molten high-temperature steel slag purification treatment system, comprising a cooling and crushing device 1, a water treatment device 3, a normal pressure cooling device 2 and a steam collecting and purifying device 4; wherein the water treatment device comprises a nozzle and a sewage purification device respectively arranged in the cooling and crushing device 1 and the normal pressure cooling device 2; the sewage purification device is used to treat and recycle the mud-containing return water generated by water spraying for recycling; the cooling and crushing device 1 comprises a granulation and crushing equipment 1-2, which is used to crush the high-temperature steel slag, and the nozzle located in the cooling and crushing device 1 is used to intermittently spray water to cool the steel slag in the granulation and crushing equipment 1-2; the normal pressure cooling device 2 comprises a cooling gas collecting hood 2-2, and the nozzle located in the normal pressure cooling device 2 is used to spray water to cool the crushed steel slag transported to the cooling gas collecting hood 2-1, and the steam collecting and purifying device 4 is respectively connected to the cooling and crushing device 1 and the cooling gas collecting hood 2-2 with a steam pipe 2-3; the steam collecting and purifying device 4 is used to purify and discharge dust-containing steam.

[0052] The high temperature steel slag in the present invention may be high temperature molten electric furnace steel slag.

[0053] When the present invention is in use, the high-temperature molten electric furnace steel slag produced by electric furnace steelmaking is transported to the processing system of the present invention through the transfer equipment, and the molten high-temperature electric furnace steel slag is first dumped through the tipping device in the cooling and crushing device, and then it is crushed several times by the granulation and crushing equipment. During the crushing process, the supporting water treatment device is interspersed with multiple water spray cooling operations, and the mud-containing return water in the treatment process is purified and recycled. Afterwards, when the electric furnace steel slag is cooled and granulated to a certain extent, the granulation and crushing device is used to push the slag and discharge it into the slag receiving container on the slag receiving and transporting equipment, and then the slag receiving container filled with electric furnace slag is successively hoisted and placed on the multi-station mobile transfer trolley in the secondary normal pressure cooling treatment device by the driving crane. After the mobile transfer trolley is loaded with the slag receiving container, it can be successively moved along the track to the cooling gas collection hood for water spray cooling treatment. The dust-containing steam generated during the treatment process can be organized to enter the supporting steam collection and purification device through the steam pipe on the top for purification and then discharged.

[0054] Furthermore, the cooling and crushing device 1 also includes a tipping device 1-1, a slag receiving container 1-4 and a slag receiving and transferring device 1-3 for transferring the slag receiving container 1-4; the tipping device 1-1 is used to pour the steel slag to be processed into the granulation and crushing device 1-2, and the molten high-temperature electric furnace steel slag at about 1300°C is treated by the cooling granulation and crushing device for about 30 minutes (time is adjustable), and the temperature can be reduced to about 500°C (temperature is adjustable), and the maximum particle size can be controlled below 300mm (particle size is adjustable). In this process, the dust-containing steam generated during the cooling and granulation treatment process can be organized through the steam pipeline to enter the matching steam collection and purification device for purification treatment to ensure the cleanliness of the treatment process. The slag receiving container 1-4 is used to receive the steel slag crushed by the cooling granulation and crushing device 1-2; the slag receiving and transferring device 1-3 (which can be a transfer trolley) is used to transfer the slag receiving container 1-4 to the atmospheric pressure cooling device 2.

[0055] Further, the granulation and crushing equipment 1-2 comprises a crushing mechanism and a traveling mechanism for driving the crushing mechanism to travel. Optionally, the crushing mechanism comprises a plurality of crushing teeth.

[0056] The traveling mechanism can make the crushing mechanism move back and forth on the track, thus solving the problem of uneven crushing caused by the liquid slag spreading in the entire crushing tank. The crushing of slag in an area of ​​10 meters can be achieved.

[0057] Furthermore, the atmospheric pressure cooling device 2 also includes a mobile transfer trolley 2-1 for transporting the slag receiving container 1-4 into the cooling gas collecting hood 2-2.

[0058] Furthermore, it also includes a track for the equipment to travel.

[0059] In the atmospheric cooling device, the mobile transfer trolley 2-1 can move along the track. According to the production and operation requirements, 1 to 3 slag receiving containers 1-4 can be placed on the vehicle body. A water spraying pipe and a nozzle are arranged on the top of the cooling gas collecting hood 2-2. At the same time, a gas collecting port is opened, which is connected to the steam collecting and purifying device 4 through the steam pipe 2-3. During the production process, after the slag receiving container 1-4 is placed, the mobile transfer trolley 2-1 moves along the track into the cooling gas collecting hood 2-2. The nozzle on the top of the cooling gas collecting hood 2-2 starts to spray water to perform secondary cooling on the electric furnace slag for about 1.5 to 3 hours. At the same time, the steam collecting and purifying device (4) is also operated, and the dust-containing steam in the process is collected and purified through the steam pipe 2-3 to ensure the cleanliness of the processing process.

[0060] Furthermore, the sewage purification device includes a water suction well 3-1, a pump room 3-2, a sludge sedimentation facility 3-3, a sludge dewatering facility 3-4 and a return water well 3-5; the return water well 3-1 is used to receive the sludge return water generated by the cooling and crushing device 1 and / or the atmospheric cooling device 2 flowing in through the pipeline; the pump room 3-2 is used to pump the sludge return water in the return water well into the sludge sedimentation facility 3-3; the sludge sedimentation facility 3-3 is used to precipitate the sludge return water; the sludge dewatering facility 3-4 is used to dewater the fine-grained steel slag sludge in the water system. The water suction well 3-1 is used to suck the supernatant in the sludge sedimentation facility and realize water reuse through the pump room.

[0061] During the production process, the return water generated by the cooling and crushing device 1 and the secondary atmospheric cooling device 2 flows into the return well 3-5 through the pipeline, and is then pumped into the sludge sedimentation facility 3-4 for sedimentation treatment by a slurry pump. The treated supernatant water flows into the suction well 3-1 and is reused by the pump group in the pump room, thereby realizing the recycling and efficient use of production water in the production process without discharging wastewater.

[0062] Further, the steam collection and purification device 4 includes a dust removal fan 4-1, a primary purification device 4-2, a secondary purification device 4-3 and an exhaust chimney 4-4;

[0063] The dust removal fan 4-1 is used to generate negative pressure to allow the dust-containing steam to enter the primary purification device 4-2 and the secondary purification device 4-3.

[0064] Furthermore, the primary purification device 4-2 includes a washing tower and a plurality of nozzles arranged in the washing tower, which are used to wash the dust particles by spraying water to the dusty flue gas. The nozzles can be set to 6, with a total water volume of about 200m 3 / h, the dust-laden flue gas is in the opposite direction to the water spraying direction. During the circulation process, the dust particles are washed down by a large amount of water, thus achieving rough purification of the dust-laden flue gas.

[0065] Furthermore, the secondary purification device 4-3 includes a high-voltage electric field and a positive plate, wherein the high-voltage electric field is used to ionize dust particles in the steam to make it negatively charged, and the positive plate is used to adsorb the ionized dust particles with negative charges. In the secondary purification device, dust particles in the steam are ionized by the high-voltage electric field to make them negatively charged, and then adsorbed onto the positive plate during circulation to be removed, thereby achieving fine dust removal of dust-containing steam.

[0066] On the other hand, a method for cleaning molten high-temperature steel slag is provided, comprising the following steps:

[0067] Pour the high-temperature slag into the cooling and crushing device for crushing and water spray cooling; the temperature is reduced by 500-900℃; the maximum particle size is controlled below 300mm;

[0068] The steel slag crushed by the cooling and crushing device is transferred to the cooling gas collecting hood; optionally, the dust-containing steam generated during the cooling and granulation process can be organized to enter the supporting steam collection and purification device through the steam pipeline for purification;

[0069] Spray water to cool the steel slag in the cooling gas collecting hood; optionally, the water spraying time is 1.5 to 3 hours;

[0070] The dusty steam generated in the cooling hood enters the steam collection and purification device from the top for purification; optionally, the dust concentration of the exhaust steam is much less than 10mg / m 3 .

[0071] Furthermore, the treatment method adopts a molten high-temperature steel slag purification treatment system for treatment.

[0072] Furthermore, in the cooling and crushing device, the water spray cooling operation is performed by interspersing multiple water sprays.

[0073] Preferably, the water spraying cycle is 20 to 40 minutes per cycle.

[0074] Preferably, in each cycle, the water spraying time is 8 to 20 minutes, and the water spraying volume is 25 to 45 m 3 / h.

[0075] According to the characteristics of electric furnace steelmaking and electric furnace slag of electric power plants, and taking into account the low content of unstable substances in electric furnace slag such as free oxidation and reformation, the present invention does not need to adopt the existing relatively complicated pressure treatment process and equipment for hot stuffy stabilization treatment. Through the optimization, adjustment and reorganization of the process scheme and the use of a set of special equipment suitable for electric furnace slag treatment, the molten high-temperature electric furnace slag can be treated quickly, efficiently and cleanly, and the slag and iron in the electric furnace slag can be effectively separated, which makes the treatment process safe and reliable, and also reduces the construction and operation costs, creating certain conditions for the rapid promotion of short-process steelmaking processes such as electric furnace steelmaking and hydrogen-based smelting.

[0076] The foregoing description of specific exemplary embodiments of the present invention is for the purpose of illustration and demonstration. These descriptions are not intended to limit the present invention to the precise form disclosed, and it is clear that many changes and variations can be made based on the above teachings. The purpose of selecting and describing the exemplary embodiments is to explain the specific principles of the present invention and its practical application, so that those skilled in the art can realize and utilize various different exemplary embodiments of the present invention and various different selections and changes. Any simple modifications, equivalent changes and modifications made to the above exemplary embodiments should fall within the scope of protection of the present invention.

Claims

1. A molten high-temperature steel slag purification treatment system, characterized in that: It includes a cooling and crushing device, a water treatment device, a normal pressure cooling device and a steam collection and purification device; wherein, The water treatment device comprises a nozzle and a sewage purification device respectively arranged in the cooling and crushing device and the normal pressure cooling device; the sewage purification device is used to process and recycle the mud-containing return water generated by the water spraying for recycling; the sewage purification device comprises a water absorption well, a pump room, a sludge sedimentation facility, a sludge dehydration facility and a return water well; The cooling and crushing device includes a granulation and crushing device for crushing high-temperature steel slag, and a nozzle located in the cooling and crushing device is used to intermittently spray water to cool the steel slag in the granulation and crushing device; The atmospheric pressure cooling device comprises a cooling gas collecting hood, and the nozzle located in the atmospheric pressure cooling device is used to spray water to cool the crushed steel slag transported to the cooling gas collecting hood; The steam collecting and purifying device is respectively connected with the cooling and crushing device and the cooling gas collecting hood by steam pipelines; the steam collecting and purifying device is used to purify and discharge the dust-containing steam; The steam collection and purification device includes a dust removal fan, a primary purification device, a secondary purification device and an exhaust chimney; The dust removal fan is used to generate negative pressure to allow dust-laden steam to enter the primary purification device and the secondary purification device; The primary purification device comprises a washing tower and a plurality of nozzles arranged in the washing tower, which are used to wash the dust particles by spraying water on the dusty flue gas; The secondary purification device comprises a high-voltage electric field and a positive plate. The high-voltage electric field is used to ionize dust particles in the steam to make it negatively charged, and the positive plate is used to adsorb the ionized dust particles with negative charges.

2. The molten high-temperature steel slag purification treatment system according to claim 1, characterized in that: The cooling and crushing device also includes a tilting device, a slag receiving container and a slag receiving and transferring device for transferring the slag receiving container; The tipping device is used to pour the steel slag to be processed into the granulation and crushing device; The slag receiving container is used to receive the steel slag crushed by the granulation and crushing equipment; The slag receiving and transferring equipment is used to transfer the slag receiving container to the atmospheric pressure cooling device.

3. The molten high-temperature steel slag purification treatment system according to claim 2, characterized in that: The granulation and crushing equipment comprises a crushing mechanism and a traveling mechanism for driving the crushing mechanism to travel.

4. The molten high-temperature steel slag purification treatment system according to claim 3, characterized in that: The crushing mechanism comprises a plurality of crushing teeth.

5. The molten high-temperature steel slag purification treatment system according to claim 2, characterized in that: The atmospheric pressure cooling device also includes a mobile transfer trolley for transporting the slag receiving container into the cooling gas collecting hood.

6. The molten high-temperature steel slag purification treatment system according to any one of claims 2 to 5, characterized in that: Also includes tracks for the equipment to travel on.

7. The molten high-temperature steel slag purification treatment system according to any one of claims 1 to 4, characterized in that: The return water well is used to receive muddy return water generated by flowing into the cooling and crushing device and / or the normal pressure cooling device through the pipeline; The pump house is used to pump the muddy return water in the return well into the sludge sedimentation facility; The sludge sedimentation facility is used for sedimentation treatment of sludge-containing return water; The sludge dewatering facility is used to dewater the fine-grained steel slag sludge in the water system; The water suction well is used to suck the supernatant in the sludge sedimentation facility and realize water reuse through the pump room.

8. A method for cleaning molten high-temperature steel slag, characterized in that: The steps include: Pour the high-temperature slag into the cooling and crushing device for crushing and water spray cooling; the temperature is reduced by 500~900℃; the maximum particle size is controlled below 300mm; The steel slag crushed by the cooling and crushing device is transferred to the cooling gas collecting hood; the dusty steam generated during the cooling and granulation process is organized into the supporting steam collection and purification device through the steam pipeline for purification; Spray water to cool the steel slag in the cooling gas collecting hood; The dusty steam generated in the cooling hood enters the steam collection and purification device from the top for purification; The treatment method adopts the molten high-temperature steel slag purification treatment system described in any one of claims 1 to 7 for treatment.

9. The processing method according to claim 8, characterized in that: When the steel slag in the cooling gas collecting hood is cooled by spraying water, the spraying time is 1.5~3h.

10. The processing method according to claim 8 or 9, characterized in that: In the cooling and crushing device, the water spray cooling operation is to intersperse multiple water sprays.

11. The processing method according to claim 8 or 9, characterized in that: The water spraying cycle is 20~40min / cycle.

12. The processing method according to claim 8 or 9, characterized in that: In each cycle, the water spraying time is 8~20min, and the water spraying volume is 25~45 m³ / h.

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