A dry process converter slag treatment system and method

Abstract

The application discloses a full-dry-method converter steel slag treatment system and method, relates to the technical field of slag treatment, and comprises screening equipment, a particle size reformation assembly, a belt conveyor, a scrap steel transfer room, a sintering ore blending room and a vertical mill, the screening equipment is provided with an inlet for receiving converter steel slag, the particle size reformation assembly comprises a water-cooled roller crusher, a water-cooled multi-roller crusher and a particle bed heat exchange boiler arranged in sequence according to procedures, the belt conveyor is connected with a heat exchange material outlet of the particle bed heat exchange boiler, and a classified magnetic separator installed on the belt conveyor is used for classifying and magnetically selecting the passing material to obtain high-quality slag steel, low-quality slag steel and non-magnetic converter tail slag. The application realizes the full-dry-method converter steel slag screening, particle size reformation, heat exchange and classified magnetic selection, achieves the purpose of full-process dry-method treatment and resource utilization of converter steel slag, solves the problems of high fresh water consumption and heat loss caused by water cooling in the high-temperature slag cooling process of the converter, and realizes the recycling of all resources.

Description

Technical Field

[0001] This invention relates to the field of slag treatment technology, and in particular to a completely dry converter steel slag treatment system and method. Background Technology

[0002] With the rapid development of the steel industry, converter slag is being processed for resource utilization through crushing and magnetic separation. Currently, the cooling process for high-temperature converter slag primarily employs water cooling, which suffers from high fresh water consumption and heat waste. This method falls under the category of wet dust removal systems for converter slag. After the converter slag has been running for a period of time through crushing and magnetic separation, scale will form on the nozzles and pipes in the system. The blockage caused by this scaling leads to high chemical dosing costs during system operation and also results in a large amount of manual cleaning.

[0003] How to achieve fully dry treatment of converter steel slag and full resource utilization of tailings are urgent problems to be solved. Summary of the Invention

[0004] To address the aforementioned issues, this application provides a fully dry converter slag treatment system and method.

[0005] This application provides a fully dry converter slag treatment system, including screening equipment, particle size reforming components, belt conveyors, scrap steel transfer room, sintering and ore blending room, and vertical grinding mill. The screening equipment has an inlet for receiving converter slag, a first outlet for outputting oversize material, and a second outlet for outputting undersize material. The particle size reforming components include a water-cooled roller crusher, a water-cooled multi-roller crusher, and a particle bed heat exchange boiler arranged sequentially. The water-cooled roller crusher has an inlet that connects to the second outlet, and the particle bed heat exchange boiler has heat exchange... The material outlet is connected to the heat exchange material outlet via a belt conveyor. The belt conveyor is equipped with a grading magnetic separator, which is used to grade and magnetically separate the passing material to obtain high-quality slag steel, low-quality slag steel, and non-magnetic converter tailings. The scrap steel transfer room is connected to the first outlet and to the outlet of the grading magnetic separator corresponding to high-quality slag steel. The sintering and ore blending room is connected to the outlet of the grading magnetic separator corresponding to low-quality slag steel and the outlet of the grading magnetic separator corresponding to non-magnetic converter tailings. The vertical grinding mill is connected to the outlet of the grading magnetic separator corresponding to non-magnetic converter tailings.

[0006] In some implementations, the belt conveyor is equipped with a first transfer bin, a second transfer bin, and a third transfer bin. The first, second, and third transfer bins correspond to the outlets of the grading magnetic separator for high-quality slag steel, low-quality slag steel, and non-magnetic converter tail slag, respectively. The scrap steel transfer room is connected to the first transfer bin, the sintering and ore blending room is connected to the second transfer bin, the sintering and ore blending room is also connected to the third transfer bin, and the vertical grinding mill is connected to the third transfer bin.

[0007] In some embodiments, the screening equipment is equipped with an electromagnet sorting mechanism, which is arranged between the first outlet of the screening equipment and the scrap steel transfer room. The electromagnet sorting mechanism is used to separate scrap steel from the material on the screen plate.

[0008] In some implementations, the screening particle size of the screening equipment is 500mm ± 20mm; the outlet output particle size of the water-cooled roller crusher is controlled to be below 380mm; and the outlet output particle size of the water-cooled multi-roller crusher is controlled to be below 10mm.

[0009] In some implementations, an infrared thermometer is installed above the material discharge point at the tail end of the belt conveyor.

[0010] In some implementations, the belt conveyor is equipped with fire detectors and dry powder fire extinguishing devices along the conveyor belt, and both the fire detectors and dry powder fire extinguishing devices are connected to the controller signal.

[0011] In some implementations, a crosscar is arranged between the inlet of the converter and the screening equipment for outputting converter slag.

[0012] A fully dry converter slag treatment method, employing the aforementioned fully dry converter slag treatment system, includes: sending converter slag to a screening device; the undersize material from the screening device is sequentially processed by a water-cooled roller crusher and a water-cooled multi-roller crusher before being sent to a granular bed heat exchange boiler; the granular bed heat exchange boiler cools the received material to below 100°C; a belt conveyor receives the material from the granular bed heat exchange boiler and sends it to a grading magnetic separator for grading and magnetic separation to obtain high-quality slag steel, low-quality slag steel, and non-magnetic converter tailings.

[0013] In some implementations, the high-quality slag steel obtained by the graded magnetic separator has a total iron content of more than 65%, the low-quality slag steel has a total iron content of 23%-65%, and the non-magnetic converter tail slag has a total iron content of less than 23% and a metallic iron content of less than 2%.

[0014] In some implementations, the oversize material and high-quality slag steel from the screening equipment are sent to the scrap steel transfer room, while the low-quality slag steel is sent to the sintering and blending room. The non-magnetic converter tailings are sent to the sintering and blending room for use as sintering and blending materials and are also sent to a vertical grinding mill for fine grinding to produce steel slag cementitious materials.

[0015] The beneficial effects of this application are as follows: It provides a fully dry converter slag treatment system, including screening equipment, particle size reforming components, belt conveyors, scrap steel transfer room, sintering and ore blending room, and vertical grinding mill. The particle size reforming components include a water-cooled roller crusher, a water-cooled multi-roller crusher, and a particle bed heat exchange boiler arranged sequentially in the process. The converter slag from the converter is a mixed solid material of slag and steel. The converter slag is fed into the screening equipment for preliminary screening. The larger particles of converter slag are sent to the scrap steel transfer room and returned to the steelmaking converter as scrap steel, while the smaller particles of converter slag are sent to the particle size reforming room. The components undergo fully dry reforming. A water-cooled roller crusher crushes and mixes the converter slag to obtain solid converter slag with a particle size smaller than a first preset value. This solid slag then passes through a water-cooled multi-roller crusher to obtain high-temperature solid converter slag particles with a particle size smaller than a second preset value. These high-temperature solid converter slag particles are then cooled by a particle bed heat exchanger. The cooled converter slag is conveyed by a belt conveyor and subjected to classification and magnetic separation by a grading magnetic separator to obtain high-quality slag steel, low-quality slag steel, and non-magnetic converter tailings. The high-quality slag steel is sent to the scrap steel transfer room for use as converter feedstock. Low-quality slag steel is sent to the sintering blending room for subsequent sinter preparation. Non-magnetic converter tailings are finely ground in a vertical mill to produce steel slag cementitious materials. Some non-magnetic converter tailings can also be sent to the sintering blending room for subsequent use as sintering blending materials. The fully dry converter steel slag treatment system provided in this application uses a fully dry method for converter steel slag screening, particle size reforming, heat exchange, and graded magnetic separation to achieve the goal of dry treatment and resource utilization of converter steel slag throughout the entire process. This fundamentally solves the problem of new water loss caused by the use of water cooling in the high-temperature slag cooling process of the converter. The high consumption and heat loss issues can be effectively avoided by wet dust removal systems during converter slag treatment, where scaling and clogging of nozzles and pipes leads to high chemical dosing costs and large manual cleaning workloads. Meanwhile, this application utilizes high-temperature converter slag for heat exchange, and after graded magnetic separation, the resulting high-quality slag steel, low-quality slag steel, and non-magnetic converter tailings are all used as resources to supply the converter, as sintering ore blending materials, and to manufacture cementitious materials, respectively. This achieves the recycling of all resources, giving this application the advantage of extremely high resource utilization. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention.

[0017] Figure 1 This is a schematic diagram of a fully dry converter slag treatment system provided in this application.

[0018] Attached diagram labels: 100-screening equipment, 110-transfer vehicle, 120-electromagnetic disk sorting mechanism, 210-water-cooled roller crusher, 220-water-cooled multi-roller crusher, 230-granular bed heat exchange boiler, 300-belt conveyor, 310-grading magnetic separator, 320-infrared thermometer, 330-fire detector, 400-scrap steel transfer room, 410-first transfer warehouse, 500-sintering and ore blending room, 510-second transfer warehouse, 600-vertical grinding mill, 610-third transfer warehouse, 20-converter. Detailed Implementation

[0019] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0020] Furthermore, reference numerals and / or reference letters may be repeated in different examples in this application. Such repetition is for simplification and clarity purposes and does not in itself indicate a relationship between the various embodiments and / or settings discussed. In addition, this application provides examples of various specific processes and materials; however, those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0021] Please refer to Figure 1 This application provides a fully dry converter slag treatment system, including screening equipment, particle size reforming components, belt conveyors, scrap steel transfer room, sintering and ore blending room and vertical grinding mill. The particle size reforming components include a water-cooled roller crusher, a water-cooled multi-roller crusher and a particle bed heat exchange boiler. The belt conveyor is equipped with a grading magnetic separator.

[0022] like Figure 1 As shown, the converter slag is sent to a screening device for screening. The converter slag is a solid mixture of slag and steel. A transfer car can be arranged between the converter and the inlet of the screening device to transfer the converter slag. The screening device is equipped with an inlet for receiving converter slag. After screening, the converter slag effectively removes the slag-steel mixture with particle sizes larger than the preset value. The metallic material on the screen after natural cooling is sent to the scrap steel transfer room as one of the sources of scrap steel and returned to the steelmaking converter.

[0023] The screening equipment has a first outlet and a second outlet. The first outlet is used to output the oversize material, and the second outlet is used to output the undersize material. Material with a particle size smaller than the preset value is sent from the second outlet to the particle size reforming unit for fully dry reforming. In the particle size reforming unit, a water-cooled roller crusher, a water-cooled multi-roller crusher, and a particle bed heat exchange boiler are arranged sequentially according to the process. The water-cooled roller crusher has an inlet that connects to the second outlet, and the particle bed heat exchange boiler has a heat exchange material outlet.

[0024] A water-cooled roller crusher crushes and mixes converter slag to obtain solid converter slag with a particle size smaller than a first preset value. This solid slag then passes through a water-cooled multi-roller crusher to obtain high-temperature solid converter slag particles with a particle size smaller than a second preset value. These high-temperature solid converter slag particles are then cooled by a particle bed heat exchanger. A belt conveyor connects to the heat exchange material outlet of the particle bed heat exchanger, and the converter slag after heat exchange continues to be conveyed via the belt conveyor. The belt conveyor is equipped with a grading magnetic separator, which performs grading and magnetic separation on the material, separating it into high-quality slag steel, low-quality slag steel, and non-magnetic converter tailings.

[0025] Please refer to Figure 1 The all-dry converter slag treatment system also includes a scrap steel transfer room, a sintering and blending room, and a vertical grinding mill. The scrap steel transfer room is connected to the first outlet of the screening equipment and also to the outlet of the high-quality slag steel corresponding to the grading magnetic separator. The sintering and blending room is connected to the outlet of the grading magnetic separator corresponding to the low-quality slag steel and the outlet of the non-magnetic converter tailings. The vertical grinding mill is connected to the outlet of the grading magnetic separator corresponding to the non-magnetic converter tailings. After obtaining high-quality slag steel, low-quality slag steel, and non-magnetic converter tailings through grading magnetic separation, the high-quality slag steel is sent to the scrap steel transfer room for use as converter feedstock, the low-quality slag steel is sent to the sintering and blending room for subsequent sintering preparation, and the non-magnetic converter tailings are finely ground by the vertical grinding mill to produce steel slag cementitious materials. Some of the non-magnetic converter tailings can also be sent to the sintering and blending room for subsequent use as sintering blending materials.

[0026] The dry converter slag treatment system provided in this application achieves the goal of dry treatment and resource utilization of converter slag throughout the entire process by using a dry method for converter slag screening, particle size reforming, heat exchange, and graded magnetic separation. It fundamentally solves the problems of high fresh water consumption and heat loss caused by water cooling during the high-temperature slag cooling process in converters. It can also effectively avoid the problems of high chemical dosing costs and large manual cleaning workload caused by scale buildup and blockage of nozzles and pipes during the operation of wet dust removal systems in converter slag treatment.

[0027] Meanwhile, this application utilizes high-temperature converter slag for heat exchange, and after graded magnetic separation, obtains high-quality slag steel, low-quality slag steel, and non-magnetic converter tailings, which will all be used as resources to supply converters, as sintering ore blending materials, and to manufacture cementitious materials, thus realizing the recycling of all resources and giving this application the advantage of extremely high resource utilization.

[0028] It should be noted that the proposed solution is for the treatment of converter steel slag. Since converter steel slag has a high temperature, all equipment must be heat-resistant. For example, the screening equipment is a high-temperature resistant screen, and the belt conveyor is a fully sealed high-temperature resistant belt conveyor.

[0029] This application specifically involves the control of particle size in multiple aspects. In some embodiments, the screening particle size of the screening equipment is 500mm ± 20mm, the outlet output particle size of the water-cooled roller crusher is controlled to be below 380mm, and the outlet output particle size of the water-cooled multi-roller crusher is controlled to be below 10mm. For example, high-temperature screening equipment can effectively remove slag-steel mixtures with a particle size greater than 500mm from converter steel slag; the water-cooled roller crusher can crush and mix high-temperature converter steel slag with a particle size less than 500mm to obtain solid converter slag with a particle size less than 380mm; the solid converter slag with a particle size less than 380mm is then processed by the water-cooled multi-roller crusher to obtain high-grade solid converter slag particles with a particle size less than 10mm.

[0030] In connection with the aforementioned scrap steel transfer station, sintering and ore blending station, and vertical grinding mill, please refer to the following in some embodiments: Figure 1 The belt conveyor is equipped with a first, second, and third transfer bin. The first transfer bin corresponds to the outlet of the high-quality slag steel via a grading magnetic separator; the second transfer bin corresponds to the outlet of the low-quality slag steel via the same separator; and the third transfer bin corresponds to the outlet of the non-magnetic converter tailings via the same separator. The scrap steel transfer room connects to the first transfer bin, the sintering and ore blending room connects to the second and third transfer bins, and the vertical grinding mill connects to the third transfer bin. The first, second, and third transfer bins temporarily store the high-quality slag steel, low-quality slag steel, and non-magnetic converter tailings separated from the belt conveyor, respectively, before being sent to the scrap steel transfer room, sintering and ore blending room, and vertical grinding mill for further processing.

[0031] In some embodiments, the screening equipment is equipped with an electromagnet sorting mechanism, which is arranged between the first outlet of the screening equipment and the scrap steel transfer room. The electromagnet sorting mechanism sorts the oversize material on the screen plate, separates the scrap steel from the oversize material, and then sends it to the scrap steel transfer room for subsequent return to the converter.

[0032] Regarding belt conveyors, due to the high temperature of the materials during material transfer, belt conveyors require certain safety measures. In some implementations, an infrared thermometer is installed above the material discharge point at the tail end of the conveyor to monitor the temperature of the high-temperature point of the material on the belt in real time during the feeding process. When the material temperature exceeds the heat resistance temperature of the belt, the belt automatically interlocks and stops, alerting personnel to conduct on-site inspection and handling, effectively preventing large-scale burning of the high-temperature resistant belt.

[0033] In some implementations, the belt conveyor is equipped with fire detectors and dry powder fire extinguishing devices along the conveyor belt. Both the fire detectors and the dry powder fire extinguishing devices are connected to the controller. Multi-frequency infrared flame detectors and resettable cable linear constant temperature detectors are used for fire detection. Dry powder fire extinguishing devices are laid out. After a fire occurs, the controller automatically activates the dry powder fire extinguishing devices to quickly extinguish initial fires and can also simultaneously trigger an automatic fire alarm.

[0034] Based on the above-mentioned dry converter slag treatment system, this application also provides a dry converter slag treatment method, which specifically includes: using a crosscar to transport converter slag to a screening device; the undersize material from the screening device is sequentially processed by a water-cooled roller crusher and a water-cooled multi-roller crusher before being sent to a granular bed heat exchange boiler; the granular bed heat exchange boiler cools the received material to below 100°C; a belt conveyor receives the material from the granular bed heat exchange boiler and sends it to a grading magnetic separator for grading and magnetic separation to obtain high-quality slag steel, low-quality slag steel, and non-magnetic converter tailings.

[0035] High-temperature solid converter slag particles are cooled by a belt conveyor and then separated by a grading magnetic separator to obtain high-quality slag steel, low-quality slag steel, and non-magnetic converter tailings. The high-quality slag steel obtained by the grading magnetic separator has a total iron content of more than 65%, the low-quality slag steel has a total iron content of 23%-65%, and the non-magnetic converter tailings have a total iron content of less than 23% and a metallic iron content of less than 2%.

[0036] After the oversize material and high-quality slag steel from the screening equipment are sent to the scrap steel transfer room, the scrap steel can be returned to the converter for use as cooling scrap during converter steelmaking. Low-quality slag steel is sent to the sintering blending room for subsequent use as sintering ore. Some non-magnetic converter tailings can also be sent to the sintering blending room for use as sintering ore. Some non-magnetic converter tailings need to be sent to a vertical grinding mill for fine grinding, which produces steel slag cementitious materials, thus realizing the resource utilization of non-magnetic converter tailings.

[0037] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0038] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0039] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A fully dry converter slag treatment system, characterized in that, include: The screening equipment is equipped with an inlet for receiving converter slag, a first outlet for outputting oversize material, and a second outlet for outputting undersize material. The particle size reforming assembly includes a water-cooled roller crusher, a water-cooled multi-roller crusher, and a particle bed heat exchange boiler arranged in sequence. The water-cooled roller crusher is provided with an inlet that connects to the second outlet, and the particle bed heat exchange boiler is provided with a heat exchange material outlet. A belt conveyor is connected to the heat exchange material outlet. The belt conveyor is equipped with a grading magnetic separator, which is used to grade and magnetically separate the passing material to obtain high-quality slag steel, low-quality slag steel and non-magnetic converter tail slag. The scrap steel transfer room is connected to the first outlet and to the outlet of the grading magnetic separator corresponding to the high-quality slag steel. The sintering and ore blending room is connected to the outlet of the grading magnetic separator corresponding to the low-quality slag steel and the outlet corresponding to the non-magnetic converter tail slag; and The vertical grinding mill is connected to the outlet of the non-magnetic converter tailings corresponding to the grading magnetic separator.

2. The all-dry converter slag treatment system as described in claim 1, characterized in that, The belt conveyor is equipped with a first transfer bin, a second transfer bin, and a third transfer bin. The first transfer bin, the second transfer bin, and the third transfer bin correspond to the outlets of the grading magnetic separator for high-quality slag steel, low-quality slag steel, and non-magnetic converter tail slag, respectively. The scrap steel transfer room is connected to the first transfer warehouse, the sintering and ore blending room is connected to the second transfer warehouse, the sintering and ore blending room is also connected to the third transfer warehouse, and the vertical grinding mill is connected to the third transfer warehouse.

3. The all-dry converter slag treatment system as described in claim 1, characterized in that, The screening equipment is equipped with an electromagnet sorting mechanism, which is arranged between the first outlet of the screening equipment and the scrap steel transfer room. The electromagnet sorting mechanism is used to separate scrap steel from the material on the screen plate.

4. The all-dry converter slag treatment system as described in claim 3, characterized in that, The screening equipment has a screening particle size of 500mm ± 20mm; The outlet output material of the water-cooled roller crusher is controlled to have a particle size of less than 380 mm; The output particle size of the water-cooled multi-roll crusher is controlled to be below 10mm.

5. The all-dry converter slag treatment system as described in claim 1, characterized in that, An infrared thermometer is installed above the material discharge point at the tail end of the belt conveyor.

6. The all-dry converter slag treatment system as described in claim 5, characterized in that, The belt conveyor is equipped with fire detectors and dry powder fire extinguishing devices along the conveyor belt, and both the fire detectors and dry powder fire extinguishing devices are connected to the controller signal.

7. The all-dry converter slag treatment system as described in claim 1, characterized in that, An overpass car is arranged between the converter for outputting the converter slag and the inlet of the screening equipment.

8. A completely dry method for treating converter steel slag, characterized in that, The dry converter slag treatment system as described in any one of claims 1-7, wherein the dry converter slag treatment method comprises: The converter slag is fed to the screening equipment; The undersize material from the screening equipment is sequentially processed by the water-cooled roller crusher and the water-cooled multi-roller crusher before being sent to the granular bed heat exchange boiler. The granular bed heat exchange boiler cools the received material to below 100°C; The belt conveyor receives material from the granular bed heat exchange boiler and sends it to the grading magnetic separator for grading and magnetic separation to obtain high-quality slag steel, low-quality slag steel and non-magnetic converter tail slag.

9. The dry converter slag treatment method as described in claim 8, characterized in that, The high-quality slag steel obtained by the graded magnetic separator has a total iron content of more than 65%, the low-quality slag steel has a total iron content of 23%-65%, and the non-magnetic converter tail slag has a total iron content of less than 23% and a metallic iron content of less than 2%.

10. The dry converter slag treatment method as described in claim 9, characterized in that, The oversize material from the screening equipment and the high-quality slag steel are sent to the scrap steel transfer room, the low-quality slag steel is sent to the sintering and blending room, and the non-magnetic converter tailings are sent to the sintering and blending room for use as sintering and blending and sent to the vertical grinding mill for fine grinding to produce steel slag cementitious materials.

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