Ferromanganese alloy dephosphorization device and method

Abstract

The device comprises a furnace body, the interior of the furnace body is divided into an oxidation dephosphorization section, a standing layering section and a reduction and manganese protection section from top to bottom, the oxidation dephosphorization section is provided with a feeding port and communicates with the standing layering section through a first discharging pipe, the first discharging pipe is connected with a second discharging pipe, and the second discharging pipe is connected with a third discharging pipe. The standing layering section is provided with a first slag discharging opening and is communicated with the reduction and manganese protection section through a third discharging pipe, the reduction and manganese protection section is communicated with a reducing agent feeding opening, the reduction and manganese protection section is provided with a second slag discharging opening and is communicated with a fourth discharging pipe, and the first discharging pipe is communicated with the fourth discharging pipe; and the oxidation dephosphorization section, the standing layering section and the reduction and manganese protection section are respectively and independently wound with intermediate-frequency coils. By adopting the three-section type dephosphorization process of oxidation dephosphorization, standing layering and reduction manganese protection, the problems that in a traditional dephosphorization process, the manganese loss rate is high, phosphorus removal is not thorough, melt composition fluctuation is large, and the occupied area of equipment is large can be effectively solved.

Description

Technical Field

[0001] This invention relates to the field of metallurgical technology, specifically to a dephosphorization device and method for ferromanganese alloys. Background Technology

[0002] Ferromanganese alloys, as indispensable alloying additives and deoxidizers in the steel industry, directly affect the mechanical properties, corrosion resistance, and processing performance of steel. Phosphorus, a common harmful element in steel, can cause cold brittleness and significantly reduce impact toughness and weldability. In recent years, with the continuous development of clean steelmaking technology, the requirements for phosphorus content in steelmaking additives and deoxidizers have become increasingly stringent. Currently, commonly used dephosphorization processes for ferromanganese alloys in industry mainly include pyrometallurgical dephosphorization and wet dephosphorization. Wet dephosphorization processes are lengthy, difficult to treat wastewater, and have low alloy yields, making large-scale industrial application difficult. Pyrometallurgical dephosphorization is mostly a single-stage oxidative dephosphorization structure, requiring a large equipment footprint and having poor separation efficiency, resulting in incomplete phosphorus removal and failing to meet the stringent phosphorus content requirements of high-end steel production. Summary of the Invention

[0003] The main objective of this invention is to overcome the deficiencies of the prior art and provide a dephosphorization device and method for ferromanganese alloys.

[0004] To achieve the above objectives, the present invention proposes a dephosphorization device for ferromanganese alloys, comprising a furnace body. The interior of the furnace body is divided from top to bottom into an oxidation dephosphorization section, a settling and stratification section, and a reduction and manganese preservation section. The top of the oxidation dephosphorization section has a feed inlet, and an oxidation atmosphere pipe is connected within the oxidation dephosphorization section, which is connected to an external oxygen source. The bottom of the oxidation dephosphorization section is connected to the settling and stratification section via a first discharge pipe. A second discharge pipe extending to the outside of the furnace body is connected to the first discharge pipe via a tee. A first slag discharge port is provided on the side wall of the settling and stratification section. The bottom of the static stratification section is connected to the reduction and manganese preservation section via a third discharge pipe. The reduction and manganese preservation section is connected to a reducing agent inlet. A second slag discharge port is opened on the side wall of the reduction and manganese preservation section. A protective atmosphere pipe is connected inside the original manganese preservation section. The protective atmosphere pipe is connected to an external protective gas source. A fourth discharge pipe is connected to the bottom of the reduction and manganese preservation section. The first discharge pipe and the fourth discharge pipe are connected. The outer walls of the oxidation and dephosphorization section, the static stratification section, and the reduction and manganese preservation section are each independently wound with a medium-frequency coil. A water-cooled jacket is fitted around the outside of the medium-frequency coil.

[0005] Furthermore, the first discharge pipe, the third discharge pipe, the second discharge pipe, and the fourth discharge pipe are each equipped with a first proportional valve.

[0006] Furthermore, the interior of the static stratification section is provided with a guide tube, and the interior of the guide tube is provided with a guide cone, with the bottom outlet of the first discharge pipe aligned with the cone apex of the guide cone.

[0007] Furthermore, each of the oxidation dephosphorization section and the settling and stratification section, as well as the settling and stratification section and the reduction and manganese preservation section, is provided with an equipment compartment. The first discharge pipe and the third discharge pipe pass through the corresponding equipment compartments. Hollow rotating shafts are coaxially fitted on the first discharge pipe and the third discharge pipe. The lower ends of the hollow rotating shafts extend into the corresponding settling and stratification sections and the reduction and manganese preservation sections, respectively. A driven gear is provided on the shaft section of the hollow rotating shaft located in the equipment compartment. A drive motor is provided in the equipment compartment. A drive gear is provided at the output end of the drive motor. The drive gear and the driven gear are meshed and connected. A slag scraper is connected to the lower end of the hollow rotating shaft.

[0008] Furthermore, the lower end of the hollow rotating shaft is provided with a spline area, and a lifting slip ring is connected to the spline area. One end of the scraper is connected to the lifting slip ring, and a lifting hydraulic cylinder is connected to the lifting slip ring.

[0009] Furthermore, the slag scraper has an L-shaped structure, and the slag scraper corresponds to the positions of the first slag discharge port and the second slag discharge port, respectively.

[0010] Furthermore, the first slag discharge port and the second slag discharge port are respectively provided with slag guide plates on the inner side of the furnace body, and the first slag discharge port and the second slag discharge port are provided with gate valves on the outer side of the furnace body.

[0011] Furthermore, ultrasonic detection devices are respectively provided above the oxidation dephosphorization section, the static stratification section, and the reduction manganese preservation section.

[0012] Furthermore, a flow divider is connected between the oxidizing atmosphere tube and the protective atmosphere tube, and a second proportional valve is provided on each of the oxidizing atmosphere tube, the protective atmosphere tube, and the flow divider.

[0013] The present invention also proposes a method for dephosphorization using the aforementioned ferromanganese alloy dephosphorization device, comprising the following steps: S1. The molten manganese-iron alloy to be dephosphorized from the smelting furnace is fed into the oxidation dephosphorization section through the feed inlet. The medium frequency coil is turned on to control the temperature of the molten manganese-iron alloy in the oxidation dephosphorization section at 1450±10℃. S2. Add the oxidative dephosphorization slagging agent into the oxidative dephosphorization section through the feed inlet. Stir the oxidative dephosphorization section by introducing argon gas from the bottom through the split pipe and oxidative atmosphere pipe to make the oxidative dephosphorization slagging agent fully mixed with the melt. Then switch to introducing oxygen to rapidly increase the oxygen potential in the oxidative dephosphorization section within 15 minutes. Then switch to introducing oxygen and argon gas simultaneously for the next 15 minutes. S3. When the ultrasonic detection device detects that the slag thickness in the oxidation dephosphorization section reaches more than 150mm, the first proportional valve on the second discharge pipe is opened to discharge the high manganese melt at the bottom of the oxidation dephosphorization section. After the melt is discharged, the first proportional valve on the first discharge pipe is opened and the first proportional valve on the second discharge pipe is closed. The molten phosphorus-rich and manganese-rich oxidized slag in the oxidation dephosphorization section enters the static stratification section without disturbance through the first discharge pipe, the guide cone, and the guide cylinder. S4. The temperature of the molten phosphorus-rich and manganese-rich oxide slag in the static stratification section is controlled at 1420±2℃. After standing for 15 minutes, the less dense phosphorus-rich slag floats upward to form the upper slag layer, and the denser manganese-rich slag sinks downward to form the lower slag layer. When the ultrasonic detection device detects that the thickness of the upper slag layer in the static stratification section reaches more than 50mm, the gate valve of the first slag discharge port is opened, and the drive motor is started to drive the scraper to rotate and scrape the upper slag layer from the first slag discharge port. When scraping the slag, the scraper drives the lifting slip ring to descend through the lifting hydraulic cylinder, thereby driving the scraper to descend and extend into the upper slag layer. Each time, a 5mm thick layer of phosphorus-rich slag is scraped off. S5. When the ultrasonic testing device detects that the thickness of the phosphorus-rich slag layer has decreased to below 5mm, stop scraping the slag, open the first proportional valve on the third discharge pipe, and discharge the bottom layer of manganese-rich slag in the static layering section into the reduction and manganese preservation section through the third discharge pipe. Then, turn on the corresponding medium frequency coil to control the temperature of the manganese-rich slag in the reduction and manganese preservation section at 1550±10℃, and add the reducing agent through the reducing agent inlet. Then, argon gas is introduced from the bottom of the reduction and manganese preservation section through the protective atmosphere pipe to establish a protective atmosphere to reduce MnO to metallic manganese and generate a low-phosphorus reduction melt. When the ultrasonic testing device detects that the thickness of the low-phosphorus reduction slag in the reduction and manganese preservation section no longer increases, start the drive motor to drive the slag scraper located in the reduction and manganese preservation section to rotate and scrape the upper layer of low-phosphorus reduction slag from the second slag outlet. Then, open the first proportional valve on the fourth discharge pipe to discharge the reduced high-manganese low-phosphorus melt and mix it with the high-manganese melt discharged from the oxidation and dephosphorization section in proportion, and cast it into a low-phosphorus manganese ferroalloy product.

[0014] The beneficial effects of this invention include: By integrating three processes—oxidative dephosphorization, static stratification, and reduction-manganese retention—into the same furnace body, this invention employs a three-stage dephosphorization process. First, oxidative dephosphorization oxidizes phosphorus to P2O5, which enters the slag phase. Then, the static stratification stage separates the phosphorus-rich slag from the manganese-rich slag. Finally, the reduction-manganese retention stage reduces the manganese oxide in the manganese-rich slag to metallic manganese, achieving manganese recovery and deep phosphorus removal. Finally, the melts from the oxidative dephosphorization and reduction-manganese retention stages are mixed in proportion, eliminating differences in composition and temperature. This effectively solves the problems of high manganese loss rate, incomplete phosphorus removal, large fluctuations in melt composition, and large equipment footprint in traditional dephosphorization processes. Attached Figure Description

[0015] Figure 1 This is an overall schematic diagram of the manganese-iron alloy dephosphorization device in an embodiment of the present invention.

[0016] Figure 2 This is a schematic diagram of the interior of the furnace body after it has been cut open in an embodiment of the present invention.

[0017] Figure 3 This is a schematic diagram of the installation of the first discharge pipe, hollow rotating shaft, guide tube, and guide cone in an embodiment of the present invention.

[0018] Figure 4 This is a schematic diagram of the first slag discharge port in an embodiment of the present invention.

[0019] Figure reference numerals: 1 Furnace body; 101 Oxidation and dephosphorization section; 102 Static stratification section; 103 Reduction and manganese preservation section; 104 Feed inlet; 105 First discharge pipe; 106 Second discharge pipe; 107 First slag discharge port; 108 Third discharge pipe; 109 Reducing agent inlet; 110 Second slag discharge port; 111 Fourth discharge pipe; 112 First proportional valve; 113 Slag guide plate; 114 Gate valve; 115 Stratification ring; 2 Oxidation atmosphere pipe; 3 Protective atmosphere pipe; 4 Medium frequency coil; 5 Water cooling jacket; 6 Guide cylinder; 7 Guide cone; 8 Equipment compartment; 9 Hollow rotating shaft; 10 Driven gear; 11 Drive motor; 12 Drive gear; 13 Slag scraper; 14 Splined area; 15 Lifting slip ring; 16 Lifting hydraulic cylinder; 17 Ultrasonic detection device; 18 Diverter pipe; 19 Second proportional valve; 20 Divider plate. Detailed Implementation

[0020] To make the technical problems, technical solutions, and beneficial effects of the embodiments of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0021] It should be noted that when a component is referred to as "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as "connected to" another component, it can be directly connected to or indirectly connected to that other component. Furthermore, a connection can be for both fixing and circuit connection purposes.

[0022] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention.

[0023] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of embodiments of the present invention, "a plurality of" means two or more, unless otherwise explicitly specified. Example 1

[0024] Please see Figures 1 to 4The dephosphorization device for ferromanganese alloy disclosed in this invention includes a furnace body 1. The furnace body 1 is divided into an oxidation dephosphorization section 101, a settling and stratification section 102, and a reduction and manganese preservation section 103, from top to bottom. An inlet 104 is provided at the top of the oxidation dephosphorization section 101. An oxidation atmosphere pipe 2 is connected to the bottom of the oxidation dephosphorization section 101 and is connected to an external oxygen source. The bottom of the oxidation dephosphorization section 101 is connected to the settling and stratification section 102 via a first discharge pipe 105. A second discharge pipe 106 extending to the outside of the furnace body 1 is connected to the first discharge pipe 105 via a tee. A first slag discharge port 107 is provided on the side wall of the settling and stratification section 102. The bottom of the settling and stratification section 102 is connected to the reduction and manganese preservation section 103 via a third discharge pipe 108. 3. The reduction and manganese preservation section 103 is connected to a reducing agent inlet 109. A second slag discharge port 110 is opened on the side wall of the reduction and manganese preservation section 103. A protective atmosphere pipe 3 is connected to the bottom of the original manganese preservation section. The protective atmosphere pipe 3 is connected to an external protective gas source, which is an argon gas source. A fourth discharge pipe 111 is connected to the bottom of the reduction and manganese preservation section 103. The first discharge pipe 105 and the fourth discharge pipe 111 are connected to each other and connected to the next production process. Medium frequency coils 4 are independently wound on the outer walls of the oxidation and dephosphorization section 101, the static stratification section 102 and the reduction and manganese preservation section 103. The medium frequency coils 4 are all electrically connected to a heating power source (not shown in the figure). A water-cooling jacket 5 is fitted on the outside of the medium frequency coils 4. The water-cooling jacket 5 is used to cool the medium frequency coils 4. Specifically, the bottoms of the oxidation dephosphorization section 101, the static stratification section 102, and the reduction manganese preservation section 103 are all designed with a conical bottom structure. One end of the first discharge pipe 105, the third discharge pipe 108, and the fourth discharge pipe 111 are all connected to the lowest end of the conical bottom structure. The first discharge pipe 105, the third discharge pipe 108, the second discharge pipe 106, and the fourth discharge pipe 111 are all ceramic iron outlet pipes. The first discharge pipe 105, the third discharge pipe 108, the second discharge pipe 106, and the fourth discharge pipe 111 are respectively equipped with a first proportional valve 112, which is used to control the conduction of the corresponding discharge pipe and adjust the flow rate of the fluid. Of course, the first discharge pipe 105 and the third discharge pipe 108 can also directly use a shut-off valve, while the second discharge pipe 106 and the fourth discharge pipe 111 need to use a proportional valve because they need to mix the two high-manganese melts in a certain proportion.In this embodiment, the molten manganese-iron alloy to be dephosphorized is fed into the oxidation dephosphorization section 101 through the feed inlet 104. The target temperature in this section is maintained by an independent intermediate frequency coil 4. Then, the desulfurization slag-forming agent is heated and oxygen is injected from the bottom to increase the oxygen potential and promote phosphorus oxidation, causing phosphorus to be oxidized to P2O5 and enter the slag. The low-phosphorus melt is separated for deep dephosphorization. Inevitably, some manganese is also oxidized at the same time to form manganese oxide, which enters the slag phase, forming a phosphorus-rich and manganese-rich oxide slag. The phosphorus-rich and manganese-rich oxide slag floats to the top, while the low-phosphorus melt sinks to the bottom. The low-phosphorus melt at the bottom is discharged to the outside through the second discharge pipe 106. The phosphorus-rich and manganese-rich oxide slag, along with a small amount of entrained low-phosphorus melt, enters the settling and stratification section 102 through the first discharge pipe 105 for settling and stratification. Similarly, the settling and stratification section 102 maintains the target temperature within this section through an independent intermediate frequency coil 4 to ensure the fluidity of the phosphorus-rich and manganese-rich oxide slag. Because the manganese-rich slag contains a large amount of manganese oxide, its density is significantly higher than that of the phosphorus-rich slag, which is mainly composed of calcium silicate; the difference in molten density between the two can reach 0.9-1.2. During the heat preservation and settling process, a significant stratification phenomenon occurs: the manganese-rich slag sinks, while the phosphorus-rich slag floats and is discharged through the first slag discharge port 107. The bottom manganese-rich slag enters the reduction and manganese preservation section 103, and the reducing agent is added through the reducing agent inlet 109 to reduce the manganese oxide in the manganese-rich slag to metallic manganese, generating a low-phosphorus reduced melt. During the reduction process, a reducing atmosphere is established by bottom blowing argon gas through the protective atmosphere pipe 3 to prevent secondary oxidation of the melt and the re-dissolution of phosphorus. After the reduction is completed, the low-phosphorus reduced slag is discharged through the second slag discharge port 110, and the high-manganese, low-phosphorus melt is discharged through the fourth discharge pipe 111 and mixed with the low-phosphorus melt in the oxidation and dephosphorization section 101 before entering the next process to eliminate differences in composition and temperature and ensure the composition of the finished product. Uniform and stable; This invention integrates three processes—oxidative dephosphorization, static stratification, and reduction for manganese preservation—into the same furnace body 1. It adopts a three-stage dephosphorization process: first, oxidative dephosphorization oxidizes phosphorus to P2O5, which enters the slag phase; then, static stratification 102 separates the phosphorus-rich slag from the manganese-rich slag; finally, reduction for manganese preservation 103 reduces the manganese oxide in the manganese-rich slag to metallic manganese, achieving manganese recovery and deep phosphorus removal. Finally, the melts from the oxidative dephosphorization and reduction for manganese preservation stages are mixed in proportion, eliminating differences in composition and temperature, effectively solving the problems of high manganese loss rate, incomplete phosphorus removal, large fluctuations in melt composition, and large equipment footprint in traditional dephosphorization processes.

[0025] In a preferred embodiment, a guide cylinder 6 is provided inside the static stratification section 102, and a guide cone 7 is provided inside the guide cylinder 6. The bottom outlet of the first discharge pipe 105 is aligned with the apex of the guide cone 7. Specifically, the top of the guide cylinder 6 is higher than the liquid level in the static stratification section 102. When the phosphorus-rich and manganese-rich oxide slag in the dephosphorization section 101 enters the static stratification section 102, it falls onto the guide cone 7, transforming the vertically downward high-speed impact flow into a radially low-speed flow that diffuses uniformly along the cone surface at 360° within the guide cylinder 6. This avoids impacting the melt in the static stratification section 102 and disrupting the stratification interface. The phosphorus-rich and manganese-rich oxide slag flows axially downward along the inner wall of the guide cylinder 6 until it reaches the bottom of the guide cylinder 6, after which it floats up and finally completes stratification in the static area outside the guide cylinder 6.

[0026] In a preferred embodiment, equipment compartments 8 are provided between the oxidation dephosphorization section 101 and the settling and stratification section 102, and between the settling and stratification section 102 and the reduction and manganese preservation section 103. The first discharge pipe 105 and the third discharge pipe 108 pass through the corresponding equipment compartments 8. Hollow rotating shafts 9 are coaxially sleeved on the first discharge pipe 105 and the third discharge pipe 108, respectively. The hollow rotating shafts 9 can rotate around the first discharge pipe 105 or the third discharge pipe 108. The lower end of the hollow rotating shafts 9 extends to the top of the corresponding settling and stratification section 102 and the reduction and manganese preservation section 103, respectively. A driven gear 10 is provided on the shaft section of the hollow rotating shaft 9 located in the equipment compartment 8. A drive motor 11 is provided in the equipment compartment 8. The output end of the drive motor 11 is provided with a drive gear 12. The drive gear 12 and the driven gear 10 are meshed and connected. A scraper plate 13 is connected to the lower end of the hollow rotating shaft 9. Specifically, the equipment compartment 8 is composed of the side wall of the furnace body 1, the bottom wall of the oxidative dephosphorization section 101 and the static layering section 102, and the partition plate 20. The side wall of the furnace body 1 does not need to be wound with the intermediate frequency coil 4 at the location corresponding to the equipment compartment. The spacing between the intermediate frequency coils 4 is increased to avoid mutual interference between them. The hollow rotating shaft 9 is driven by the drive motor 11 to rotate and drive the slag scraper 13 to rotate and scrape off the slag layer.

[0027] In a preferred embodiment, a splined area 14 is provided at the lower end of the hollow rotating shaft 9. A lifting slip ring 15 is connected to the splined area 14. The lifting slip ring 15 can slide and rise on the splined area 14 but cannot rotate. One end of the scraper plate 13 is connected to the lifting slip ring 15, and a lifting hydraulic cylinder 16 is connected to the lifting slip ring 15. Specifically, the scraper plate 13 has an L-shaped structure, and the scraper plate 13 corresponds to the positions of the first slag discharge port 107 and the second slag discharge port 110. A guide plate 113 is provided on the inner side of the first slag discharge port 107 and the second slag discharge port 110, respectively. The guide plate 113 is vertically inclined towards the slag discharge port. When the scraper plate 13 rotates to the corresponding slag discharge port position, the guide plate 113 can guide the slag into the interior of the slag discharge port. A gate valve 114 is provided on the side of the first slag discharge port 107 and the second slag discharge port 110 outside the furnace body 1. The lifting hydraulic cylinder 16 is a servo hydraulic cylinder, which can adjust the lifting stroke. The lifting hydraulic cylinder 16 drives the lifting slip ring 15 to move up and down on the spline area 14 of the hollow rotating shaft 9 to adjust the depth of the scraper 13 into the slag layer. A layering ring 115 is protruding on the inner wall of the static layering section 102. The vertical cross section of the layering ring 115 is a right trapezoid. The layering ring 115 is located at the lowest point of the first slag discharge port 107. The inner diameter of the layering ring 115 is 1 / 4 of the inner diameter of the static layering section 102. The height of the layering ring 115 in the static layering section 102 is the preset thickness of the manganese-rich slag layer. The layering ring 115 is above the thickness of the phosphorus-rich slag layer, which further improves the stability of the interface during slag scraping.

[0028] In a specific embodiment, ultrasonic testing devices 17 are respectively installed above the oxidation dephosphorization section 101, the settling and stratification section 102, and the reduction manganese preservation section 103. The ultrasonic testing devices 17 are used to detect the thickness of the slag layer, and the ultrasonic testing devices 17 adopt existing commercially available equipment.

[0029] In a preferred embodiment, a diversion pipe 18 is connected between the oxidizing atmosphere pipe 2 and the protective atmosphere pipe 3. The oxidizing atmosphere pipe 2, the protective atmosphere pipe 3 and the diversion pipe 18 are respectively provided with a second proportional valve 19. The second proportional valve 19 is preferably an electric or pneumatic proportional regulating valve. The protective atmosphere (argon) can be delivered to the oxidation and dephosphorization section 101 through the diversion pipe 18. The second proportional valve 19 can control the atmosphere flow rate. Example 2

[0030] Please continue reading. Figures 1 to 4The present invention also proposes a method for dephosphorizing using the above-mentioned ferromanganese alloy dephosphorization device, comprising the following steps: S1. The ferromanganese alloy melt to be dephosphorized obtained from the smelting furnace is fed into the oxidation dephosphorization section 101 through the feed inlet 104, and the intermediate frequency coil 4 is turned on to control the temperature of the ferromanganese alloy melt in the oxidation dephosphorization section 101 at 1450±10℃; S2. An oxidation dephosphorization slagging agent is added into the oxidation dephosphorization section 101 through the feed inlet 104. The oxidation dephosphorization slagging agent is a lime-fluorite-iron ore composite slagging agent, or a red mud-based oxidation dephosphorization slagging agent (modified red mud 55% + quicklime 25% + fluorite 15%). Argon gas (3% magnesium powder + 2% sodium carbonate) is introduced from the bottom of the dephosphorization section 101 through the split pipe 18 and the oxidation atmosphere pipe 2 for stirring. No oxygen is introduced during the stirring process to control the low initial oxygen potential in the dephosphorization section 101. After the dephosphorization slag-forming agent is fully mixed with the melt, oxygen is introduced. Within 15 minutes, the oxygen potential in the dephosphorization section 101 is rapidly increased, avoiding competitive oxidation of manganese caused by a slow increase in oxygen potential, and ensuring that most of the phosphorus oxidation reaction is completed in a short time. In the following 15 minutes, oxygen and argon are introduced simultaneously at a volume ratio of 1:2. While maintaining the oxygen potential, a gentle stirring action is continued to be provided to promote the mass transfer process of the dephosphorization reaction and ensure that the phosphorus in the slag phase is evenly distributed.S3. When the ultrasonic testing device 17 detects that the slag thickness in the dephosphorization section 101 reaches more than 150 mm, the first proportional valve 112 on the second discharge pipe 106 is opened to discharge the high-manganese melt at the bottom of the dephosphorization section 101. After the melt is discharged, the first proportional valve 112 on the first discharge pipe 105 is opened and the first proportional valve 112 on the second discharge pipe 106 is closed. The molten phosphorus-rich and manganese-rich oxide slag in the dephosphorization section 101 enters the settling and stratification section 102 without disturbance through the first discharge pipe 105, the guide cone 7, and the guide cylinder 6, avoiding slag-metal mixing and improving subsequent stratification efficiency. S4. The temperature of the molten phosphorus-rich and manganese-rich oxide slag in the settling and stratification section 102 is controlled at 1420±2℃. After settling for 15 minutes, the less dense phosphorus-rich slag floats upward to form the upper slag layer, and the more dense manganese-rich slag sinks downward to form the lower slag layer. When the ultrasonic testing device 17 detects that the slag thickness of the upper slag layer in the settling and stratification section 102 reaches more than 50 mm, Open the gate valve 114 of the first slag discharge port 107, start the drive motor 11 to drive the scraper 13 to rotate and scrape the upper slag layer from the first slag discharge port 107. When scraping slag, the scraper 13 drives the lifting slip ring 15 to descend through the lifting hydraulic cylinder 16, thereby driving the scraper 13 to descend and extend into the upper slag layer, scraping off a 5mm thick layer of phosphorus-rich slag each time, avoiding the entrainment of manganese-rich slag caused by scraping too deeply, and effectively reducing the manganese loss rate; S5. When the ultrasonic detection device 17 detects the rich phosphorus slag... When the thickness of the phosphorus slag layer decreases to below 5mm, stop scraping the slag, open the first proportional valve 112 on the third discharge pipe 108, and discharge the manganese-rich slag at the bottom of the static stratification section 102 into the reduction and manganese preservation section 103 through the third discharge pipe 108. Then, turn on the corresponding intermediate frequency coil 4 to control the temperature of the manganese-rich slag in the reduction and manganese preservation section 103 at 1550±10℃. First, add quicklime at 5% of the mass of the manganese-rich slag through the reducing agent inlet 109 to control the alkalinity of the manganese-rich slag at 3.0-3.5. Argon gas is introduced from the bottom of the reduction manganese preservation section 103 through the protective atmosphere pipe 3 to establish an oxygen-free protective atmosphere. Then, ferrosilicon alloy reducing agent is added through the reducing agent inlet 109 to reduce MnO to metallic manganese and generate a low-phosphorus reduction melt. When the ultrasonic detection device 17 detects that the thickness of the low-phosphorus reduction slag in the reduction manganese preservation section 103 no longer increases, the reduction reaction reaches its endpoint. The drive motor 11 is started to drive the scraper plate 13 located in the reduction manganese preservation section 103 to rotate and scrape the upper layer of low-phosphorus reduction slag from the second slag outlet 110. Then, the first proportional valve 112 on the fourth discharge pipe 111 is opened to discharge the reduced high-manganese low-phosphorus melt and mix it with the high-manganese melt discharged from the oxidation dephosphorization section 101 in a ratio of 1:3. The mixture is then cast into a low-phosphorus ferromanganese alloy product with a phosphorus content ≤0.05%.

[0031] The background section of this invention may include background information about the problems or environment in which the invention is being developed, and is not necessarily a description of prior art. Therefore, the content included in the background section does not constitute an admission of prior art by the applicant.

[0032] The above description provides a further detailed explanation of the present invention in conjunction with specific / preferred embodiments, and it should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various substitutions or modifications can be made to these described embodiments without departing from the concept of the present invention, and all such substitutions or modifications should be considered within the scope of protection of the present invention. In the description of this specification, the reference to terms such as "an embodiment," "some embodiments," "preferred embodiment," "example," "specific example," or "some examples," etc., indicates that the specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any suitable manner in one or more embodiments or examples. Without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification and the features of different embodiments or examples. Although the embodiments of the present invention and their advantages have been described in detail, it should be understood that various changes, substitutions, and modifications can be made herein without departing from the scope of protection of the patent application.

Claims

1. A dephosphorization device for ferromanganese alloys, characterized in that: The furnace includes a furnace body, the interior of which is divided from top to bottom into an oxidation dephosphorization section, a settling and stratification section, and a reduction and manganese preservation section. The top of the oxidation dephosphorization section has a feed inlet, and an oxidation atmosphere pipe is connected within the section, which is connected to an external oxygen source. The bottom of the oxidation dephosphorization section is connected to the settling and stratification section via a first discharge pipe. A second discharge pipe extending to the outside of the furnace body is connected to the first discharge pipe via a tee. The side wall of the settling and stratification section has a first slag discharge port, and the bottom of the settling and stratification section is connected to... The reduction and manganese preservation section is connected to the third discharge pipe, which is connected to a reducing agent inlet. A second slag discharge port is opened on the side wall of the reduction and manganese preservation section. A protective atmosphere pipe is connected inside the original manganese preservation section, and the protective atmosphere pipe is connected to an external protective gas source. A fourth discharge pipe is connected to the bottom of the reduction and manganese preservation section. The first discharge pipe and the fourth discharge pipe are connected. The outer walls of the oxidation and dephosphorization section, the static stratification section and the reduction and manganese preservation section are each independently wound with a medium frequency coil. A water-cooled jacket is fitted around the outside of the medium frequency coil.

2. The dephosphorization device for ferromanganese alloy as described in claim 1, characterized in that: Each of the first discharge pipe, the third discharge pipe, the second discharge pipe, and the fourth discharge pipe is equipped with a first proportional valve.

3. The dephosphorization device for ferromanganese alloy as described in claim 2, characterized in that: The static stratification section is equipped with a flow guide cylinder inside, and the flow guide cylinder is equipped with a flow guide cone inside. The bottom outlet of the first discharge pipe is aligned with the cone apex of the flow guide cone.

4. The dephosphorization device for ferromanganese alloy as described in claim 3, characterized in that: Equipment compartments are provided between the oxidation dephosphorization section, the settling and stratification section, and the reduction and manganese preservation section. The first discharge pipe and the third discharge pipe pass through the corresponding equipment compartments. Hollow rotating shafts are coaxially fitted on the first discharge pipe and the third discharge pipe. The lower ends of the hollow rotating shafts extend into the corresponding settling and stratification sections and the reduction and manganese preservation sections, respectively. A driven gear is provided on the shaft section of the hollow rotating shaft located in the equipment compartment. A drive motor is provided in the equipment compartment. A drive gear is provided at the output end of the drive motor. The drive gear and the driven gear are meshed and connected. A slag scraper is connected to the lower end of the hollow rotating shaft.

5. The dephosphorization device for ferromanganese alloy as described in claim 4, characterized in that: The lower end of the hollow rotating shaft is provided with a spline area, and a lifting slip ring is connected to the spline area. One end of the slag scraper is connected to the lifting slip ring, and a lifting hydraulic cylinder is connected to the lifting slip ring.

6. The dephosphorization device for ferromanganese alloy as described in claim 5, characterized in that: The slag scraper has an L-shaped structure, and the slag scraper corresponds to the positions of the first slag discharge port and the second slag discharge port, respectively.

7. The dephosphorization device for ferromanganese alloy as described in claim 6, characterized in that: The first slag discharge port and the second slag discharge port are respectively provided with slag guide plates on the inner side of the furnace body, and the first slag discharge port and the second slag discharge port are provided with gate valves on the outer side of the furnace body.

8. The dephosphorization device for ferromanganese alloy as described in claim 7, characterized in that: An ultrasonic detection device is provided above the oxidation dephosphorization section, the static stratification section, and the reduction manganese preservation section, respectively.

9. The dephosphorization device for ferromanganese alloy as described in claim 8, characterized in that: A flow divider is connected between the oxidizing atmosphere tube and the protective atmosphere tube, and a second proportional valve is provided on each of the oxidizing atmosphere tube, the protective atmosphere tube, and the flow divider.

10. A method for dephosphorizing ferromanganese alloys, characterized in that, Dephosphorization using the ferromanganese alloy dephosphorization device as described in claim 9 includes the following steps: S1. The molten manganese-iron alloy to be dephosphorized from the smelting furnace is fed into the oxidation dephosphorization section through the feed inlet. The medium frequency coil is turned on to control the temperature of the molten manganese-iron alloy in the oxidation dephosphorization section at 1450±10℃. S2. Add the oxidative dephosphorization slagging agent into the oxidative dephosphorization section through the feed inlet. Stir the oxidative dephosphorization section by introducing argon gas from the bottom through the split pipe and oxidative atmosphere pipe to make the oxidative dephosphorization slagging agent fully mixed with the melt. Then switch to introducing oxygen to rapidly increase the oxygen potential in the oxidative dephosphorization section within 15 minutes. Then switch to introducing oxygen and argon gas simultaneously for the next 15 minutes. S3. When the ultrasonic detection device detects that the slag thickness in the oxidation dephosphorization section reaches more than 150mm, the first proportional valve on the second discharge pipe is opened to discharge the high manganese melt at the bottom of the oxidation dephosphorization section. After the melt is discharged, the first proportional valve on the first discharge pipe is opened and the first proportional valve on the second discharge pipe is closed. The molten phosphorus-rich and manganese-rich oxidized slag in the oxidation dephosphorization section enters the static stratification section without disturbance through the first discharge pipe, the guide cone, and the guide cylinder. S4. The temperature of the molten phosphorus-rich and manganese-rich oxide slag in the static stratification section is controlled at 1420±2℃. After standing for 15 minutes, the less dense phosphorus-rich slag floats upward to form the upper slag layer, and the denser manganese-rich slag sinks downward to form the lower slag layer. When the ultrasonic detection device detects that the thickness of the upper slag layer in the static stratification section reaches more than 50mm, the gate valve of the first slag discharge port is opened, and the drive motor is started to drive the scraper to rotate and scrape the upper slag layer from the first slag discharge port. When scraping the slag, the scraper drives the lifting slip ring to descend through the lifting hydraulic cylinder, thereby driving the scraper to descend and extend into the upper slag layer. Each time, a 5mm thick layer of phosphorus-rich slag is scraped off. S5. When the ultrasonic testing device detects that the thickness of the phosphorus-rich slag layer has decreased to below 5mm, stop scraping the slag, open the first proportional valve on the third discharge pipe, and discharge the bottom layer of manganese-rich slag in the static layering section into the reduction and manganese preservation section through the third discharge pipe. Then, turn on the corresponding medium frequency coil to control the temperature of the manganese-rich slag in the reduction and manganese preservation section at 1550±10℃, and add the reducing agent through the reducing agent inlet. Then, argon gas is introduced from the bottom of the reduction and manganese preservation section through the protective atmosphere pipe to establish a protective atmosphere to reduce MnO to metallic manganese and generate a low-phosphorus reduction melt. When the ultrasonic testing device detects that the thickness of the low-phosphorus reduction slag in the reduction and manganese preservation section no longer increases, start the drive motor to drive the slag scraper located in the reduction and manganese preservation section to rotate and scrape the upper layer of low-phosphorus reduction slag from the second slag outlet. Then, open the first proportional valve on the fourth discharge pipe to discharge the reduced high-manganese low-phosphorus melt and mix it with the high-manganese melt discharged from the oxidation and dephosphorization section in proportion, and cast it into a low-phosphorus manganese ferroalloy product.

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