A rare earth alloy feeding device and a control method thereof

Abstract

This invention discloses a rare earth alloy feeding device and its control method. The device includes a slag layer thickness detection component, a slag layer purging component, a pneumatic feeding component, a position adjustment component, and a control component. The slag layer thickness detection component is located at the top of the molten steel container and is used to obtain the real-time slag layer thickness. The control component is electrically connected to each component and calculates the first control parameters of the purging component and the second control parameters of the feeding component based on the real-time slag layer thickness, additive physical property parameters, and a preset depth for adding to the molten steel. The position adjustment component moves the purging component and the feeding component to a preset feeding position. First, the slag layer is purged according to the first control parameters to form a slag-free channel, and then the additive is added to the molten steel at the preset depth through the slag-free channel according to the second control parameters. By detecting the slag layer thickness in real time and combining it with the additive physical property parameters, the purging and feeding parameters are dynamically matched to improve the rare earth yield and compositional uniformity, and solve the problems of slag-metal reaction, oxidation loss, and uncontrollable addition position.

Description

Technical Field

[0001] This invention relates to the field of iron and steel metallurgy technology, and in particular to a rare earth alloy feeding device and its control method. Background Technology

[0002] Rare earth elements play a crucial role in steel by purifying molten steel, refining grains, modifying inclusions, and microalloying, making them an effective way to improve the corrosion resistance and mechanical properties of steel. However, existing rare earth addition processes are insufficient to meet the demands of industrial-scale rare earth steel production, hindering the widespread application of rare earth elements in the steel industry. The main reasons are twofold: firstly, rare earth elements are chemically reactive and have significantly lower densities and melting points than molten steel. During addition, they readily react with the slag covering the molten steel, resulting in slag-metal reactions and oxidation losses. This not only reduces the rare earth yield but also severely impacts the compositional stability of the molten steel and slag system. Secondly, due to their own buoyancy and the viscous resistance of the molten steel, rare earth additives are difficult to add to the effective depth of the ladle, leading to uneven distribution of rare earth elements in the molten steel and resulting in significant fluctuations in the performance of the finished steel.

[0003] To address these issues, existing technologies typically improve the melting behavior of rare earth additives in molten steel by optimizing their physicochemical properties. For example, increasing the iron content in the rare earth additive can reduce its activity and minimize the difference in melting point and density between it and the molten steel. However, since its density and melting point still cannot exceed those of the molten steel, this method has limited effectiveness in improving rare earth yield and compositional uniformity. Furthermore, excessively high iron content can lead to increased rare earth additive usage, negatively impacting molten steel temperature control and the compactness of the metallurgical process. Another common approach is the ladle injection method, where the rare earth additive is placed in a semi-enclosed container and injected into the molten steel using a plunger. Some methods supplement this with bottom air blowing or a slag isolation hood to mitigate the impact of slag layer. While this method allows for controllable injection location, it suffers from problems such as short container life, easy contamination of the molten steel, poor equipment compatibility, complex structure, and cumbersome operation. In addition, although the crystallizer wire feeding method can significantly improve the rare earth yield and avoid continuous casting nozzle blockage, the melting position of rare earth wire is greatly affected by factors such as the flow of molten steel and the wire feeding speed, resulting in uneven distribution of rare earth in the billet and unstable yield.

[0004] In summary, to meet the needs of industrialized rare earth steel production, it is urgent to develop a rare earth alloy feeding device and method that can dynamically match the steel smelting environment. This would allow for the precise addition of rare earth additives to a specified depth in the molten steel while suppressing the slag-metal reaction, thereby effectively solving the technical problems of slag-metal reaction, oxidation loss, low yield, and poor composition uniformity in existing technologies. Summary of the Invention

[0005] The purpose of this invention is to provide a rare earth alloy feeding device and its control method. By real-time detection of slag layer thickness and dynamic matching of purging and feeding parameters with additive property parameters, a slag-free channel is formed through the slag layer, and rare earth additives are accurately delivered to a preset depth in the molten steel. This significantly improves the rare earth recovery rate and the uniformity of rare earth components in the molten steel, effectively solving the technical problems of slag-metal reaction, oxidation loss, and uncontrollable addition position in the prior art.

[0006] To solve the above-mentioned technical problems, a first aspect of the present invention provides a rare earth alloy feeding device, comprising: a slag layer thickness detection component, a slag layer purging component, a pneumatic feeding component, a position adjustment component, and a control component; The slag layer thickness detection component is set at a preset position on the top of the molten steel container to obtain the real-time slag layer thickness of the top layer of molten steel inside the molten steel container. The control component is electrically connected to the slag layer thickness detection component, the slag layer purging component, and the pneumatic feeding component, respectively. The control component calculates the first real-time control parameters of the slag layer purging component and the second real-time control parameters of the pneumatic feeding component based on the real-time slag layer thickness, combined with the physical property parameters of the rare earth alloy additive and the preset depth of the added molten steel. The control component then drives the slag layer purging component to purge the slag layer at the preset feeding position according to the first real-time control parameters, and drives the pneumatic feeding component to add the rare earth alloy additive at the slag layer purging position according to the second real-time control parameters.

[0007] Furthermore, the rare earth alloy feeding device also includes: an additive detection component; The additive detection component is positioned at a corresponding location in the additive conveying channel of the pneumatic feeding component to acquire the physical property parameters of the rare earth alloy additive to be added in real time and send them to the control component.

[0008] Furthermore, the slag layer purging assembly includes: a gas storage tank, an electromagnetic control valve, a pressure regulator, and a directional purging port connected in sequence by air passages; The control component is electrically connected to the pressure regulator. Based on the real-time slag layer thickness, it calculates the first air pressure value and purging time at the outlet of the pressure regulator. Based on the first air pressure value and the purging time, it controls the high-pressure inert gas in the gas storage tank to be injected through the directional purging port into the slag layer corresponding to the preset feeding station, thereby obtaining a slag-free channel that penetrates the slag layer.

[0009] Furthermore, the formula for calculating the first air pressure value is as follows: ; in, As the reference slag layer thickness, This is the pressure increment coefficient. Real-time slag layer thickness; The formula for calculating the purging time is: ; in, This is the duration increment coefficient.

[0010] Furthermore, the pneumatic feeding assembly includes: a sealed hopper, a gate valve, an adjustable air source, and a feeding channel; The adjustable pressure gas source stores high-pressure inert gas to push the rare earth alloy additive; The air inlet of the sealed hopper is connected to the air outlet of the adjustable pressure air source; The slide gate valve is located at the air outlet of the sealed hopper, and the slide gate valve is electrically connected to the control component. The feeding channel inlet is connected to the air outlet of the sealed silo via the slide valve; The control component calculates the second pressure value after the gate valve is opened based on the physical property parameters of the rare earth alloy additive to be added and the preset depth of the molten steel to be added, and adjusts the adjustable pressure source based on the second pressure value to introduce the rare earth alloy additive into the preset depth of the molten steel through the slag-free channel.

[0011] Furthermore, the physical properties of the rare earth alloy additive include: additive weight and additive particle size, and the second real-time control parameter includes: second gas pressure value; The formula for calculating the second air pressure value after the gate valve is opened is as follows: ; in, Based on the pressure of push, For comprehensive correction factors, The viscosity of molten steel under standard conditions. The density of molten steel under standard conditions. This is the weight of the additives. For additive particle size, To preset the viscosity of molten steel, To preset the molten steel density, The preset depth for adding molten steel.

[0012] Accordingly, a second aspect of the present invention provides a method for controlling a rare earth alloy feeding device, for controlling the aforementioned rare earth alloy feeding device, comprising the following steps: The control component moves the slag layer purging component and the pneumatic feeding component to the preset feeding station. The slag layer thickness is detected by the slag layer thickness detection component at the preset feeding station in real time, and the physical property parameters of the rare earth alloy additive to be added are obtained. The real-time slag layer thickness and the physical property parameters of the rare earth alloy additive to be added are sent to the control component. Based on the real-time slag layer thickness, the physical property parameters of the rare earth alloy additive to be added, and the preset depth of the added molten steel, calculate the first real-time control parameter for controlling the slag layer purging assembly and the second real-time control parameter for controlling the pneumatic feeding assembly. The control component controls the slag layer blowing component to blow the slag layer at the corresponding position of the preset feeding station according to the first real-time control parameters, thereby obtaining a slag-free channel that runs through the slag layer. The control component controls the pneumatic feeding component to feed the rare earth alloy additive into the molten steel to a preset depth via the slag-free channel, based on the second real-time control parameters.

[0013] Furthermore, the physical properties of the rare earth alloy additive include: additive weight and additive particle size; The first real-time control parameters include: a first air pressure value and a purging duration; The second real-time control parameter includes: the second air pressure value.

[0014] Furthermore, the formula for calculating the first air pressure value is as follows: ; in, As the reference slag layer thickness, This is the pressure increment coefficient. Real-time slag layer thickness; The formula for calculating the purging time is: ; in, This is the duration increment coefficient.

[0015] Furthermore, the second real-time control parameter includes: a second air pressure value; The formula for calculating the second air pressure value is: ; in, Based on the pressure of push, For comprehensive correction factors, The viscosity of molten steel under standard conditions. The density of molten steel under standard conditions. This is the weight of the additives. For additive particle size, To preset the viscosity of molten steel, To preset the molten steel density, The preset depth for adding molten steel.

[0016] The above-described technical solutions of the embodiments of the present invention have the following beneficial technical effects: 1. By collecting the slag layer thickness in real time through online detection, and by dynamically calculating the purging pressure and purging time based on the slag layer thickness by the control component, the slag layer purging component is driven to carry out directional and precise purging of the slag layer above the preset feeding station, forming a stable slag-free channel through the slag layer. This effectively avoids rare earth additives from coming into contact with molten slag during the feeding process, significantly inhibits slag-metal reaction and oxidation loss, greatly improves the recovery rate of rare earth in molten steel, and solves the technical problem of severe rare earth loss due to slag layer coverage in the existing technology. 2. By obtaining the weight and particle size of rare earth additives in real time through online detection, and combining the preset viscosity, density and target addition depth of molten steel, the control component dynamically calculates the push pressure, which drives the pneumatic feeding component to accurately deliver the rare earth additives to the preset depth inside the molten steel through the slag-free channel. This effectively overcomes the problem that rare earth additives are stuck in the shallow surface of molten steel due to the influence of buoyancy and viscous resistance, significantly improves the uniformity of rare earth element distribution in molten steel, and solves the technical problem of large composition fluctuations caused by the uncontrollable addition position in traditional feeding methods. 3. The lifting and horizontal movement positioning of the slag layer purging component and the pneumatic feeding component are realized through the position adjustment component. The control component implements closed-loop dynamic control of the entire process of slag layer thickness detection, purging parameter calculation, feeding parameter calculation, purging execution and feeding execution. This enables the device to adaptively match the feeding requirements of different molten steel containers, different slag layer conditions and different rare earth additive specifications, significantly improving the versatility of the equipment and the flexibility of on-site operation, reducing the difficulty of production line modification and replacement, and meeting the diversified needs of rare earth feeding process in steel industrial production. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the principle of the rare earth alloy feeding device provided in the embodiment of the present invention; Figure 2 This is a flowchart of the control method for the rare earth alloy feeding device provided in an embodiment of the present invention.

[0018] Figure label: 1. Slag layer thickness detection component; 2. Slag layer purging component; 21. Gas storage tank; 22. Pressure regulator; 23. Directional purging port; 3. Pneumatic feeding component; 31. Sealed silo; 32. Slide valve; 33. Feeding channel; 4. Position adjustment component; 5. Additive detection component. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments and the accompanying drawings. It should be understood that these descriptions are merely exemplary and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0020] Please refer to Figure 1 The first aspect of this invention provides a rare earth alloy feeding device, comprising: a slag layer thickness detection component 1, a slag layer purging component 2, a pneumatic feeding component 3, a position adjustment component 34, and a control component. The slag layer thickness detection component 1 is positioned at a preset position on top of the molten steel container to obtain the real-time slag layer thickness at the top layer of the molten steel inside the container. The control component is electrically connected to the slag layer thickness detection component 1, the slag layer purging component 2, the pneumatic feeding component 3, and the position adjustment component 34. Based on the real-time slag layer thickness, combined with the physical properties of the rare earth alloy additive and the preset depth of addition to the molten steel, the control component calculates a first real-time control parameter for the slag layer purging component 2 and a second real-time control parameter for the pneumatic feeding component 3. The control component then uses the position adjustment component 34 to drive the slag layer purging component 2 at a preset feeding position according to the first real-time control parameter, and drives the pneumatic feeding component 3 at the slag layer purging position to add the rare earth alloy additive according to the second real-time control parameter.

[0021] During operation, when rare earth alloy feeding is required, the position adjustment component 34 first moves the slag layer purging component 2 and the pneumatic feeding component 3 to the preset feeding position according to the instructions of the control component. The slag layer thickness detection component 1 then detects the slag layer thickness at the position in real time and sends the detected slag layer thickness data to the control component. After receiving the slag layer thickness data, the control component performs real-time calculations based on the pre-input or stored rare earth alloy additive property parameters and the preset depth of the target molten steel to be added, generating the first real-time control parameters for controlling the slag layer purging component 2 and the second real-time control parameters for controlling the pneumatic feeding component 3.

[0022] In one embodiment of the present invention, the physical property parameters of the rare earth alloy additive to be added can be directly received data after testing, or they can be pre-tested ready-made data. Specifically, before the feeding operation begins, the operator can input the tested additive weight W and particle size D to the control component through on-site entry, database retrieval, or transmission from the upper-level system. In this embodiment, the device body does not need to be equipped with a dedicated additive testing component 5; the control component directly receives and stores the aforementioned ready-made data as physical property parameters. It should be noted that regardless of the method used to obtain the additive's physical property parameters, the slag layer thickness testing component 1 always operates in real time, continuously collecting the real-time slag layer thickness H at the preset feeding position in the molten steel container, and sending this thickness data to the control component to ensure that the purging parameters can be dynamically matched according to the real-time changes in the slag layer.

[0023] In another embodiment of the present invention, the rare earth alloy feeding device further includes: an additive detection component 5; the additive detection component 5 is disposed at a corresponding position in the additive conveying channel of the pneumatic feeding component 3, and acquires the physical property parameters of the rare earth alloy additive to be added in real time, and sends them to the control component. The additive detection component 5 is disposed at a corresponding position in the pneumatic feeding component 3, specifically at the inlet front end of the sealed silo 31 or the feed inlet of the feeding channel 33, and integrates a weight sensor and a particle size morphology identifier inside. During the feeding process, before the rare earth alloy additive enters the silo via the conveying device, the additive detection component 5 collects the weight W and particle size D of each batch or each piece of additive in real time, and sends these real-time physical property parameters to the control component. At the same time, the slag layer thickness detection component 1 works synchronously, continuously collecting the real-time slag layer thickness H at the preset feeding station and sending it to the control component. The control component dynamically calculates the purging pressure P1, purging duration T1, and pushing pressure P2 based on the real-time received slag layer thickness H and additive physical property parameters W and D, combined with the preset molten steel viscosity μ, density ρ, and target addition depth Lt, to achieve real-time matching and precise control of slag layer purging and pneumatic feeding parameters.

[0024] The physical properties of the rare earth alloy additives are acquired in real time by an online additive detection component 5, specifically involving two parameters: weight (W) and particle size (D). This additive detection component 5 integrates a weight sensor and a particle size morphology identifier. Preferably, both are located at the inlet front of the sealed silo 31. Before the rare earth additives enter the silo via the conveying device, they first pass through this detection area: the weight sensor is used to determine the mass of a single piece or batch of additives, with a measurement accuracy of ±0.1g; the particle size morphology identifier works in conjunction with the weight sensor to measure the equivalent diameter of the additives through image recognition or laser scanning, and can identify particle sizes in the range of 1-300mm. The above detection process is completed dynamically before feeding. The online detection component works continuously, collecting the weight and particle size data of each batch or piece of additive in real time, and sending the collected W and D values ​​to the control component in real time.

[0025] Based on the first real-time control parameters, the slag layer purging component 2 performs directional purging of the slag layer at the preset feeding station, causing the slag layer in that area to spread outwards and form a slag-free channel penetrating the slag layer. Subsequently, the pneumatic feeding component 3, based on the second real-time control parameters, feeds rare earth alloy additives into the molten steel along this slag-free channel, reaching the preset target feeding depth. Throughout the feeding process, the control component uses the position adjustment component 34 to precisely adjust the positions of each actuator, ensuring that the purging and feeding actions are always aligned with the preset station.

[0026] Through the above-described process, the device achieves real-time monitoring of slag layer thickness, dynamic matching of purging parameters, and precise control of feeding depth. In the slag purging stage, adjusting the purging intensity based on the real-time slag layer thickness effectively forms a stable slag-free channel, preventing rare earth additives from contacting the molten slag. In the pneumatic feeding stage, the pushing pressure is dynamically adjusted based on the real-time data collected by the additive detection component 5, which monitors the physical properties of the rare earth alloy additive to be added and the characteristics of the molten steel. This allows the additive to overcome buoyancy and viscous resistance to reach the designated depth within the molten steel. This technical solution automates and refines the rare earth feeding process, effectively suppressing slag-metal reaction and oxidation loss, improving rare earth yield, and enhancing the uniformity of rare earth element distribution in the molten steel.

[0027] In one embodiment of the present invention, the slag layer purging assembly 2 includes: a gas storage tank 21, an electromagnetic control valve, a pressure regulator 22, and a directional purging port 23 connected in sequence by air passages; the control assembly is electrically connected to the pressure regulator 22, calculates the first air pressure value and purging time at the outlet of the pressure regulator 22 based on the real-time slag layer thickness, and controls the high-pressure inert gas in the gas storage tank 21 to be injected through the directional purging port 23 to the slag layer corresponding to the preset feeding position based on the first air pressure value and the purging time, thereby obtaining a slag-free channel penetrating the slag layer.

[0028] Gas storage tank 21 serves as a high-pressure inert gas source device, pre-filled with inert gas at a preset pressure. Argon, nitrogen, or helium is typically selected, with argon being the preferred choice. The outlet of this storage tank is connected to the inlet of an electromagnetic control valve via a high-pressure resistant pipe. The electromagnetic control valve, acting as the actuator for gas flow control and regulation, has its control terminal electrically connected to the control component. Its response time is controllable within 50ms, and it receives electrical signals from the control component to adjust the valve opening accordingly. The outlet of the electromagnetic control valve is connected to the inlet of a pressure regulator 22 via a pipe. The pressure regulator 22 is used for precise pressure regulation of the input gas; its outlet pressure can be accurately set within the range of 0.3-1.2MPa according to control commands, with an adjustment accuracy of ±0.01MPa. The outlet of the pressure regulator 22 is finally connected to the inlet of the directional purging port 23. The directional purging port 23 serves as the gas injection end, with its outlet facing the slag layer surface inside the molten steel container. Different nozzles with different orifice diameters can be replaced according to the characteristics of the slag layer to adapt to different working conditions.

[0029] During operation, when slag layer purging is required, the control component first calculates the first real-time control parameters, namely the first air pressure value P1 and the purging duration T1, based on the real-time collected slag layer thickness H and according to the preset control logic. The control component sends the first air pressure value P1 as the target pressure signal to the pressure regulator 22 and simultaneously sends an opening command to the electromagnetic control valve. After receiving the command, the electromagnetic control valve opens, and the high-pressure inert gas in the gas storage tank 21 enters the pressure regulator 22 through the electromagnetic control valve. The pressure regulator 22 adjusts the gas pressure in real time according to the received target pressure signal to stabilize the outlet pressure at the P1 value, and then delivers the pressure-adjusted gas to the directional purging port 23. The directional purging port 23 sprays the high-pressure inert gas in the form of a directional jet onto the slag layer surface corresponding to the preset feeding position for a duration of T1. During the purging process, the impact force of the high-pressure airflow causes the slag layer to diffuse and displace in all directions. As the purging proceeds, the slag layer in this area is gradually pushed away, eventually forming a slag-free channel penetrating the upper and lower surfaces of the slag layer. This slag-free channel leads directly to the molten steel below, providing an unobstructed feeding path for subsequent pneumatic feeding and effectively preventing rare earth additives from coming into contact with the slag layer.

[0030] Specifically, the formula for calculating the first atmospheric pressure value is: ; in, As the reference slag layer thickness, This is the pressure increment coefficient. Real-time slag layer thickness; The formula for calculating the purging time is: ; in, This is the duration increment coefficient.

[0031] In this embodiment of the invention, the purging pressure and purging duration of the slag layer purging component 2 are dynamically calculated based on the real-time slag layer thickness H, specifically using the following control formulas. The calculation formula for the first air pressure value P1 is P1=0.3+K1×(H-H0), where P1 is in MPa, H0 is the reference slag layer thickness, set to 80mm according to the conventional working conditions in metallurgical sites; K1 is the pressure increment coefficient, with a value range of 0.005-0.015 MPa / mm. This coefficient reflects the degree of influence of changes in slag layer thickness on the required purging pressure; the thicker the slag layer, the greater the required pressure increment. The calculation formula for the purging duration T1 is T1=2+K2×(H-H0), where T1 is in seconds, and K2 is the duration increment coefficient, with a value range of 0.1-0.2 s / mm, used to characterize the additional time compensation required when the slag layer thickness increases. When the real-time slag layer thickness H is less than or equal to the reference thickness H0, P1 = 0.3 MPa and T1 = 2 s are used, i.e., the operation is performed using the basic purging parameters. Through the above calculation formula, the control component can automatically match and output appropriate purging pressure and purging time according to the real-time collected slag layer thickness H, ensuring that a stable slag-free channel can be formed under different slag layer conditions. This avoids insufficient purging leading to incomplete channel opening, and also prevents excessive purging from causing energy waste or excessive exposed steel area.

[0032] In one embodiment of the present invention, the pneumatic feeding assembly 3 includes: a sealed silo 31, a gate valve 32, an adjustable pressure air source, and a feeding channel 33; the adjustable pressure air source stores high-pressure inert gas for pushing rare earth alloy additives; the air inlet of the sealed silo 31 is connected to the air outlet of the adjustable pressure air source; the gate valve 32 is disposed at the air outlet of the sealed silo 31 and is electrically connected to the control assembly; the inlet of the feeding channel 33 is connected to the air outlet of the sealed silo 31 through the gate valve 32; the control assembly calculates the second pressure value after the gate valve 32 is opened based on the physical property parameters of the rare earth alloy additives and the preset depth of the molten steel, and adjusts the adjustable pressure air source based on the second pressure value to feed the rare earth alloy additives into the molten steel to the preset depth through the slag-free channel.

[0033] The component includes a sealed hopper 31, a gate valve 32, an adjustable pressure gas source, and a feeding channel 33. All components are mechanically connected to the gas path to form a complete feeding path. The adjustable pressure gas source serves as the power source and stores the high-pressure inert gas required to push the rare earth alloy additive. Typically, argon, nitrogen, or helium is selected, with argon being preferred. The gas source output pressure is set to a range of 0.2-1.5 MPa. The sealed hopper 31 temporarily stores the rare earth additive to be added. Its inlet is connected to the outlet of the adjustable pressure gas source via a pressure-resistant pipe to ensure that high-pressure gas can enter the hopper and apply a pushing force to the additive. The gate valve 32 is installed at the outlet of the sealed hopper 31. As a key valve controlling the release of the additive, its valve body is electrically connected to the control component, allowing it to receive control commands for rapid opening and closing, with a response time meeting closed-loop control requirements. The inlet of the feeding channel 33 is connected to the outlet of the sealed silo 31 via a gate valve 32, and its outlet is positioned towards the molten steel in the molten steel container and extends to a position close to the liquid surface to guide the additive into the molten steel along a predetermined path. Optionally, the adjustable pressure air source in the pneumatic feeding assembly 3 can be the same device as the gas storage tank 21.

[0034] During the actual feeding process, the control component first calculates the second real-time control parameter, namely the second air pressure value P2, based on the real-time data of the rare earth additive weight W and particle size D collected by the online additive detection component 5, combined with the preset steel viscosity μ, steel density ρ, and target addition depth Lt, according to the preset control model. The control component sends the calculated P2 value as the target pressure to the adjustable pressure air source, which adjusts the output gas pressure to P2 accordingly. After the slag purging component completes the purging operation and the slag-free channel is stably established, the control component sends an opening command to the slide valve 32. The slide valve 32 opens rapidly, and the rare earth additive in the sealed silo 31 enters the feeding channel 33 under the push of the high-pressure inert gas, and then travels at high speed through the slag-free channel, finally reaching the target addition depth Lt inside the molten steel. Through the above dynamic matching control, the pneumatic feeding component 3 can adaptively adjust the pushing pressure for rare earth additives of different weights and particle sizes, as well as for steel liquid with different viscosities and densities, to ensure that the additives overcome buoyancy and viscous resistance and accurately reach the predetermined depth, thus significantly improving the uniformity of rare earth element distribution in the steel liquid.

[0035] Furthermore, the physical properties of the rare earth alloy additives include: additive weight and additive particle size, and the second real-time control parameters include: second gas pressure value; The formula for calculating the second air pressure value after the slide valve 32 is opened is: ; in, Based on the pressure of push, For comprehensive correction factors, The viscosity of molten steel under standard conditions. The density of molten steel under standard conditions. This is the weight of the additives. For additive particle size, To preset the viscosity of molten steel, To preset the molten steel density, The preset depth for adding molten steel.

[0036] The pushing pressure of the pneumatic feeding system is dynamically calculated based on real-time collected rare earth additive physical property parameters and molten steel characteristic parameters, specifically involving the determination of the second air pressure value P2. The rare earth alloy additive physical property parameters include the real-time collected additive weight W and additive particle size D, where W is in grams and D is in millimeters. The calculation formula for the second air pressure value P2 in the second real-time control parameter comprehensively reflects the influence of the additive's own characteristics, molten steel physical property parameters, and the target addition depth on the required pushing pressure. In the formula, P0 is the base push pressure, with a value of 0.2 MPa; K3 is the comprehensive correction coefficient, with a value ranging from 0.05 to 0.2, used to adjust the calculation results based on the on-site working conditions; μ0 is the standard state molten steel viscosity, taken as 0.008 Pa·s; ρ0 is the standard state molten steel density, taken as 7 g / cm³; μ is the preset molten steel viscosity, in Pa·s, input by the operator according to the actual steel type; ρ is the preset molten steel density, in g / cm³, also preset according to the steel type; Lt is the preset depth of molten steel addition, in meters, representing the target position that the rare earth additive needs to reach. Through the above calculation formula, the control component can dynamically calculate the appropriate second air pressure value P2 based on the real-time collected weight W and particle size D, combined with the preset molten steel viscosity μ, density ρ, and target depth Lt, and adjust the output pressure of the adjustable pressure air source accordingly. When W is larger, D is smaller, Lt is deeper, μ is larger, or ρ is larger, the required pushing pressure P2 increases accordingly to ensure that the rare earth additive can overcome the buoyancy and viscous resistance of the molten steel, accurately pass through the slag-free channel and reach the predetermined depth, so as to achieve the uniform distribution of rare earth elements in the molten steel.

[0037] Accordingly, please refer to Figure 2 A second aspect of the present invention provides a method for controlling a rare earth alloy feeding device, for controlling the aforementioned rare earth alloy feeding device, comprising the following steps: Step S100: Based on the control component, move the slag layer purging component 2 and the pneumatic feeding component 3 to the preset feeding position.

[0038] First, the control component sends a control command to the position adjustment component 34 based on the preset feeding position information, driving the slag layer purging component 2 and the pneumatic feeding component 3 to move in the horizontal and vertical directions until the purging port and the outlet of the feeding channel 33 are aligned with the preset feeding position above the molten steel container. The above positioning process ensures the accuracy of subsequent purging and feeding actions, laying the foundation for the formation of a stable slag-free channel and precise feeding.

[0039] Step S200: Based on the slag layer thickness detection component 1, detect the real-time slag layer thickness corresponding to the preset feeding station, and obtain the physical property parameters of the rare earth alloy additive to be added, and send the real-time slag layer thickness and the physical property parameters of the rare earth alloy additive to be added to the control component.

[0040] The slag layer thickness detection component 1 starts detection at the preset feeding station, obtaining the vertical distance between the upper surface of the slag layer and the reference surface of the molten steel at that location through laser ranging or radar ranging, i.e., the real-time slag layer thickness H. Simultaneously, a weight sensor and particle size analyzer detect the rare earth alloy additive to be added, collecting the weight W and particle size D of the additive, respectively. The above detection data are transmitted to the control component in real time via electrical signal transmission, serving as the basic input variables for subsequent parameter calculations. Taking the LF refining furnace operation as an example, the slag layer thickness detection component 1 operates continuously above the ladle, with a sampling frequency exceeding 10Hz, ensuring the ability to capture instantaneous changes in slag layer fluctuations.

[0041] Meanwhile, the physical properties of the rare earth alloy additive to be added can be obtained in two ways: In one embodiment, the additive weight W and particle size D are pre-tested ready-made data, which the operator inputs into the control component through on-site entry, database retrieval, or transmission from the upper-level system; In another embodiment, the additive detection component 5 of the device collects the additive weight W and particle size D in real time during the feeding process and sends the detection data to the control component. The aforementioned real-time slag layer thickness H and the additive physical properties W and D are jointly sent to the control component via electrical signal transmission as the basic input variables for subsequent parameter calculations. Taking the LF refining furnace as an example, the slag layer thickness detection component 1 works continuously above the ladle and can respond to changes in the slag layer in real time. Whether the additive physical properties are obtained through pre-stored data or real-time detection, they can be accurately transmitted to the control system before feeding, providing complete data support for the dynamic matching of purging and feeding parameters.

[0042] Step S300: Based on the real-time slag layer thickness, the physical property parameters of the rare earth alloy additive to be added, and the preset depth of the added molten steel, calculate the first real-time control parameters for controlling the slag layer purging component 2 and the second real-time control parameters for controlling the pneumatic feeding component 3.

[0043] Specifically, the physical properties of rare earth alloy additives include: additive weight and additive particle size; the first real-time control parameters include: first gas pressure value and purging time; the second real-time control parameters include: second gas pressure value.

[0044] Accordingly, the formula for calculating the first atmospheric pressure value is: ; in, As the reference slag layer thickness, This is the pressure increment coefficient. Real-time slag layer thickness; The formula for calculating the purging time is: ; in, This is the duration increment coefficient.

[0045] Accordingly, the second real-time control parameter includes: a second air pressure value; the formula for calculating the second air pressure value is: ; in, Based on the pressure of push, For comprehensive correction factors, The viscosity of molten steel under standard conditions. The density of molten steel under standard conditions. This is the weight of the additives. For additive particle size, To preset the viscosity of molten steel, To preset the molten steel density, The preset depth for adding molten steel.

[0046] After receiving the real-time slag layer thickness H, additive weight W, and particle size D, the control component, in conjunction with the pre-input or database-retrieved molten steel viscosity μ, molten steel density ρ, and target addition depth Lt, performs calculations according to the built-in control model. For slag layer purging control, the control component calculates the first air pressure value P1 and purging duration T1 based on the H value. Specifically, when H is greater than the reference thickness H0 = 80 mm, P1 increases by an increment coefficient K1 = 0.005-0.015 MPa / mm based on 0.3 MPa, and T1 increases by a duration increment coefficient K2 = 0.1-0.2 s / mm based on 2 seconds; when H is less than or equal to H0, P1 = 0.3 MPa and T1 = 2 s are used. For pneumatic feeding control, the control component calculates the second air pressure value P2 based on W, D, μ, ρ, and Lt, where the base pushing pressure P0 = 0.2 MPa, the comprehensive correction coefficient K3 ranges from 0.05 to 0.2, the standard viscosity μ0 = 0.008 Pa·s, and the standard density ρ0 = 7 g / cm³. This calculation formula reflects the physical law that the greater the additive weight, the smaller the particle size, the deeper the target depth, and the higher the viscosity or density of the molten steel, the higher the required pushing pressure.

[0047] In step S400, the slag layer blowing component 2 is controlled by the control component to blow the slag layer at the corresponding position of the preset feeding station according to the first real-time control parameters, so as to obtain a slag-free channel that runs through the slag layer.

[0048] The control component sends the calculated first air pressure value P1 and purging duration T1 as control commands to the slag layer purging component 2. Upon receiving the command, the electromagnetic control valve opens, and the pressure regulator 22 precisely adjusts the gas pressure to P1. High-pressure inert gas is then jetted from the directional purging port 23 onto the slag layer surface at the preset feeding position. During the purging process lasting T1 seconds, the high-pressure airflow propels the slag layer to diffuse outwards, gradually forming a slag-free channel penetrating the upper and lower surfaces of the slag layer. This channel leads directly to the molten steel below, providing an unobstructed path for subsequent feeding. During the purging process, the slag layer thickness detection component 1 monitors the channel formation status in real time. When it detects that the slag layer has been completely blown open, the control component confirms that the slag-free channel has been stably established.

[0049] In step S500, the pneumatic feeding component 3 is controlled by the control component according to the second real-time control parameters to feed the rare earth alloy additive into the molten steel through the slag-free channel to the preset depth.

[0050] After the slag-free channel is established, the control component sends the calculated second air pressure value P2 to the adjustable pressure air source, which adjusts the output pressure to P2. Simultaneously, the control component sends an opening command to the gate valve 32, which quickly opens. The rare earth alloy additive in the sealed hopper 31 enters the feeding channel 33 under the impetus of high-pressure inert gas and rapidly traverses the slag-free channel formed in step S400, ultimately reaching the target addition depth Lt inside the molten steel. After feeding is completed, the control component closes the gate valve 32, completing a single feeding cycle. If multiple batches are required, the above steps can be repeated. This control method achieves fully automated closed-loop control from positioning, detection, calculation to purging and feeding, ensuring that the rare earth additive accurately reaches the predetermined depth while avoiding slag layer interference.

[0051] The above control method will be further illustrated below with several embodiments: This invention prepared rare earth additives of different weights and sizes and rare earth cored wires with a diameter of 5 mm through experiments. The uniformity of rare earth composition and yield in the continuous casting billet were compared between the direct feeding method, the ladle insertion method, the crystallizer wire feeding method and the method of this invention after adding 100 ppm of rare earth in the refining-continuous casting process at the smelting site.

[0052] The process of adding rare earth additives to the ladle is as follows: LF vacuum refining for 20 minutes, with vacuum <60 Pa during refining, followed by 6 minutes of bottom blowing with argon. Rare earth additives are then added using different methods. After 5 minutes of bottom blowing with argon following the addition of rare earths, the ladle is then fed into continuous casting. The process of feeding rare earth wire into the crystallizer is as follows: Wire feeding begins after continuous casting starts and a stable billet shell forms in the crystallizer. The rare earth wire is first straightened using a straightening device and then fed uniformly at a speed of 1.5-3 m / min through a guide tube on the side of the top opening of the crystallizer. Simultaneously, the liquid level fluctuation in the crystallizer is monitored and controlled within ±3 mm, and the cooling water flow rate is adjusted to prevent abnormal billet shell formation. Finally, the rare earth alloying is completed as the billet descends. Sudden changes in wire feeding speed or interruption of wire supply must be avoided throughout the process. The initial casting speed of the crystallizer during continuous casting is 0.8 m / min, and the billet cross-sectional dimensions are 300*2000 mm.

[0053] Furthermore, the sampling methods for slag and billets in the refining furnace under different processes are as follows: After adding rare earth elements and blowing argon for 5 minutes, slag samples and steel samples from the LF ladle are taken to test and verify the rare earth content; steel samples are taken from the upper and lower sections of the front, middle, and rear ends of the continuously cast billet to test the rare earth yield and compositional uniformity. The rare earth content in the steel is determined according to the scheme of GB / T 223.92-2023 "Determination of Lanthanum, Cerium, Praseodymium, Neodymium and Samarium Content in Iron and Steel and Alloys - Inductively Coupled Plasma Mass Spectrometry".

[0054] Comparative Example 1 Rare earth addition tests were conducted in the 200t LF refining-continuous casting process of Q355 weathering steel. After vacuum refining in the LF furnace for 20 minutes and low-pressure argon blowing for 6 minutes, rare earth alloy blocks were added to the ladle manually. Following argon bottom blowing for 5 minutes, slag and steel samples were taken from the furnace. Continuous casting then commenced, with an initial casting speed of 0.8 m / min and a billet cross-sectional size of 300*2000 mm. After the completion of this heat, steel samples were taken from the upper and lower sections of the front, middle, and rear ends of the continuously cast billet to test the rare earth yield and compositional uniformity.

[0055] Comparative Example 2 Rare earth addition tests were conducted in the 200t LF refining-continuous casting process of Q355 weathering steel. First, rare earth alloy blocks were loaded into the rare earth addition container. After vacuum refining in the LF furnace for 20 minutes and low-pressure argon blowing for 6 minutes, the addition container was inserted into the bottom of the ladle. Following this, argon bottom blowing was performed for 5 minutes, and slag and steel samples were taken from the furnace. Continuous casting then commenced, with an initial casting speed of 0.8 m / min and a billet cross-sectional size of 300*2000 mm. After the completion of this heat, steel samples were taken from the upper and lower sections of the front, middle, and rear ends of the continuously cast billet to test the rare earth yield and compositional uniformity.

[0056] Comparative Example 3 Rare earth addition tests were conducted in the 200t LF refining-continuous casting process of Q355 weathering steel. After the LF furnace was fully charged and casting began, and a stable billet shell formed in the crystallizer, wire feeding was initiated. The rare earth wire was first straightened using a straightening device and then fed in at a uniform speed of 1.5-3 m / min via a guide pipe on the side of the crystallizer's upper opening. Simultaneously, the liquid level fluctuation in the crystallizer was monitored and controlled within ±3 mm, and the cooling water flow rate was adjusted to prevent abnormal billet shell formation. Finally, the rare earth alloying was completed as the billet descended. Sudden changes in wire feeding speed or wire supply interruptions must be avoided throughout the process. The initial crystallizer speed during continuous casting was 0.8 m / min, and the billet cross-sectional dimensions were 300*2000 mm. After the casting cycle was completed, steel samples were taken from the upper and lower sections of the front, middle, and rear ends of the continuously cast billet to test the rare earth yield and compositional uniformity.

[0057] Example 1 Rare earth addition experiments were conducted in the 200t LF refining-continuous casting process for Q355 weathering steel. First, the hopper opening was moved to the appropriate level and height using a multi-directional adjustment system. Then, rare earth additives were placed in each of the separate conveyor bins. The intermittent conveying time was set to 15 seconds. In the PCL unit, with preset parameters μ=0.009, ρ=7.1 g / cm³, and Lt=1.5 m, data were collected at H=100mm, W=8000g, and D=50 mm. Calculations were performed as follows: P1=0.3+0.008×(100−80)=0.46 MPaP1=0.46MPa; T1 = 2 + 0.15 × 20 = 5 s; P2=0.2+0.12×8000 / 502×1.5×0.009 / 0.008×7.1 / 7≈0.86 MPa After the material is fed into the silo, the transmission system stops and the vertical slide valve is closed. High-pressure inert gas is then introduced into the sealed silo. After pressurization, the slag purging system is activated to fully purge the slag from the surface of the molten steel below the feed port. The horizontal slide valve is then opened, and the rare earth ferroalloy is precisely injected into the designated position in the molten steel under inert gas pressure. After this is completed, the horizontal slide valve is closed. After all the rare earth has been added, argon bottom blowing is performed for 5 minutes, followed by slag and steel samples from the furnace. Continuous casting then begins, with an initial casting speed of 0.8 m / min in the continuous casting crystallizer. The billet cross-sectional dimensions are 300*2000 mm. After the entire furnace casting cycle is completed, steel samples are taken from the upper and lower sections of the front, middle, and rear ends of the continuously cast billet to test the rare earth yield and compositional uniformity.

[0058] Example 2 Rare earth addition experiments were conducted in the 200t LF refining-continuous casting process of Q345 weathering steel. First, the silo opening was moved to the appropriate level and height using a multi-directional adjustment system. Then, rare earth additives were placed in each of the separate conveyor bins. The intermittent conveying time was set to 15 seconds. In the PCL unit, with preset values ​​of μ=0.009, ρ=7.1 g / cm3, and Lt=1500 mm, the following parameters were collected: H=70 mm, W=8000 g, D=50 mm, and L=1800 mm. P1=0.3 MPa and T1=2 seconds were also selected.

[0059] P2=0.2+0.12×8000 / 502×1.5×0.009 / 0.008×7.1 / 7≈0.86 MPa After the material is fed into the silo, the transmission system stops and the vertical slide valve is closed. High-pressure inert gas is then introduced into the sealed silo. After pressurization, the slag purging system is activated to fully purge the slag from the surface of the molten steel below the feed port. The horizontal slide valve is then opened, and the rare earth ferroalloy is precisely injected into the designated position in the molten steel under inert gas pressure. After this is completed, the horizontal slide valve is closed. After all the rare earth has been added, argon bottom blowing is performed for 5 minutes, followed by slag and steel samples from the furnace. Continuous casting then begins, with an initial casting speed of 0.8 m / min in the continuous casting crystallizer. The billet cross-sectional dimensions are 300*2000 mm. After this heat is completed, steel samples are taken from the upper and lower sections of the front, middle, and rear ends of the continuously cast billet to test the rare earth yield and compositional uniformity.

[0060] Example 3 Rare earth addition experiments were conducted in the 170 t LF refining-continuous casting process of DH36 high-strength ship plate steel. First, the hopper opening was moved to the appropriate level and height using a multi-directional adjustment system. Then, rare earth additives were placed in each of the separate conveyor bins. The intermittent conveying time was set to 15 seconds. In the PCL unit, with preset values ​​of μ=0.009, ρ=6.9 g / cm³, and Lt=0.4 m, data were collected showing H=160 mm, W=1500 g, and D=83.6 mm. Calculations were then performed... P1=0.3+0.011×(160−80)=1.2 MPa; T1 = 2 + 0.1 × (160 − 80) = 10 s; P2=0.2+0.05×1500 / 83.62×0.4×0.009 / 0.008×6.9 / 7≈0.2 MPa After the material is fed into the silo, the transmission system stops and the vertical slide valve is closed. High-pressure inert gas is then introduced into the sealed silo. After pressurization, the slag purging system is activated to fully purge the slag from the surface of the molten steel below the feed port. The horizontal slide valve is then opened, and the rare earth ferroalloy is precisely injected into the designated position in the molten steel under inert gas pressure. After this is completed, the horizontal slide valve is closed. After all the rare earth has been added, argon bottom blowing is performed for 5 minutes, followed by slag and steel samples from the furnace. Continuous casting then begins, with an initial casting speed of 0.8 m / min in the continuous casting crystallizer. The billet cross-sectional dimensions are 300*2000 mm. After this heat is completed, steel samples are taken from the upper and lower sections of the front, middle, and rear ends of the continuously cast billet to test the rare earth yield and compositional uniformity.

[0061] Example 4 Rare earth addition experiments were conducted in the 200t LF refining-continuous casting process for Q355 weathering steel. First, the silo opening was moved to the appropriate level and height using a multi-directional adjustment system. Then, rare earth additives were placed in each of the separate conveyor bins. The intermittent conveying time was set to 15 seconds. In the PCL unit, with preset parameters μ=0.009, ρ=7.1g / cm³, and Lt=1.9 m, the following parameters were obtained: H=160mm, W=12000g, and D=63.2 mm. Calculations were then performed... P1=0.3+0.011×(160−80)=1.2 MPa; T1 = 2 + 0.1 × (160 − 80) = 10 s; P2=0.2+0.2×12000 / 63.22×1.9×0.009 / 0.008×7.1 / 7≈1.5 MPa After the material is fed into the silo, the transmission system stops and the vertical slide valve is closed. High-pressure inert gas is then introduced into the sealed silo. After pressurization, the slag purging system is activated to fully purge the slag from the surface of the molten steel below the feed port. The horizontal slide valve is then opened, and the rare earth ferroalloy is precisely injected into the designated position in the molten steel under inert gas pressure. After this is completed, the horizontal slide valve is closed. After all the rare earth has been added, argon bottom blowing is performed for 5 minutes, followed by slag and steel samples. Continuous casting then begins, with an initial casting speed of 0.8 m / min in the continuous casting crystallizer. The billet cross-sectional dimensions are 300*2000 mm. After this heat is completed, samples are taken from the upper and lower sections of the front, middle, and rear ends of the continuously cast billet to test the rare earth yield and compositional uniformity.

[0062] Example 5 Rare earth addition experiments were conducted in the 200t LF refining-continuous casting process of DH36 ship plate steel. First, the hopper opening was moved to the appropriate level and height using a multi-directional adjustment system. Then, rare earth additives were placed in each of the separate conveyor bins. The intermittent conveying time was set to 15 seconds. In the PCL unit, with preset values ​​of μ=0.009, ρ=7.1 g / cm³, and Lt=1.5 m, the following parameters were obtained: H=160 mm, W=7000 g, and D=50 mm. Calculations were then performed... P1=0.3+0.008×(160−80)=0.36 MPa; T1 = 2 + 0.1 × 8 = 10 s; P2=0.2+0.2×7000 / 502×1.5×0.009 / 0.008×7.1 / 7≈1.15MPa After the material is fed into the silo, the transmission system stops and the vertical slide valve is closed. High-pressure inert gas is then introduced into the sealed silo. After pressurization, the slag purging system is activated to fully purge the slag from the surface of the molten steel below the feed port. The horizontal slide valve is then opened, and the rare earth ferroalloy is precisely injected into the designated position in the molten steel under inert gas pressure. After this is completed, the horizontal slide valve is closed. After all the rare earth has been added, argon bottom blowing is performed for 10 minutes, followed by slag and steel samples from the furnace. Continuous casting then begins, with an initial casting speed of 0.8 m / min in the continuous casting crystallizer. The billet cross-sectional dimensions are 400*1000 mm. After the entire furnace casting cycle is completed, steel samples are taken from the upper and lower sections of the front, middle, and rear ends of the continuously cast billet to test the rare earth yield and compositional uniformity.

[0063] Example 6 Rare earth addition experiments were conducted in the 120t LF refining-continuous casting process of DH36 ship plate steel. First, the hopper opening was moved to the appropriate level and height using a multi-directional adjustment system. Then, rare earth additives were placed in each of the separate conveyor bins. The intermittent conveying time was set to 15 seconds. In the PCL unit, with preset parameters μ=0.009, ρ=6.9 g / cm³, and Lt=1 m, the following parameters were collected: H=110 mm, W=6000 g, and D=40 mm. Calculations were then performed... P1=0.3+0.009×(110−80)=0.57 MPa; T1 = 2 + 0.1 × 8 = 10 s; P2=0.2+0.2×6000 / 402×1.5×0.009 / 0.008×6.9 / 7≈1.03MPa After the material is fed into the silo, the transmission system stops and the vertical slide valve is closed. High-pressure inert gas is then introduced into the sealed silo. After pressurization, the slag purging system is activated to fully purge the slag from the surface of the molten steel below the feed port. The horizontal slide valve is then opened, and the rare earth ferroalloy is precisely injected into the designated position in the molten steel under inert gas pressure. After this is completed, the horizontal slide valve is closed. After all the rare earth has been added, argon bottom blowing is performed for 5 minutes, followed by slag and steel samples. Continuous casting then begins, with an initial casting speed of 0.7 m / min in the continuous casting crystallizer. The billet cross-sectional dimensions are 300*1200 mm. After the entire furnace casting cycle is completed, steel samples are taken from the upper and lower sections of the front, middle, and rear ends of the continuously cast billet to test the rare earth yield and compositional uniformity.

[0064] Example 7 Rare earth addition experiments were conducted in the 250t LF refining-continuous casting process for Q450 ship plate steel. First, the hopper opening was moved to the appropriate level and height using a multi-directional adjustment system. Then, rare earth additives were placed in each of the separate conveyor bins. The intermittent conveying time was set to 15 seconds. In the PCL unit, with preset values ​​of μ=0.009, ρ=6.9 g / cm³, and Lt=1.8 m, the following parameters were obtained: H=140 mm, W=9000 g, and D=55 mm. Calculations were performed... P1=0.3+0.01×(140−80)=0.9 MPa; T1 = 2 + 0.1 × 6 = 8 s; P2=0.2+0.15×9000 / 552×1.8×0.009 / 0.008×6.9 / 7≈0.69MPa After the material is fed into the silo, the transmission system stops and the vertical slide valve is closed. High-pressure inert gas is then introduced into the sealed silo. After pressurization, the slag purging system is activated to fully purge the slag from the surface of the molten steel below the feed port. The horizontal slide valve is then opened, and the rare earth ferroalloy is precisely injected into the designated position in the molten steel under inert gas pressure. After this is completed, the horizontal slide valve is closed. After all the rare earth has been added, argon bottom blowing is performed for 5 minutes, followed by slag and steel samples. Continuous casting then begins, with an initial casting speed of 0.7 m / min in the continuous casting crystallizer. The billet cross-sectional dimensions are 300*1200 mm. After the entire furnace casting cycle is completed, steel samples are taken from the upper and lower sections of the front, middle, and rear ends of the continuously cast billet to test the rare earth yield and compositional uniformity.

[0065] Example 8 Rare earth addition experiments were conducted in the 200t LF refining-continuous casting process for Q450 ship plate steel. First, the hopper opening was moved to the appropriate level and height using a multi-directional adjustment system. Then, rare earth additives were placed in each of the separate conveyor bins. The intermittent conveying time was set to 15 seconds. In the PCL unit, with preset values ​​of μ=0.009, ρ=6.9 g / cm³, and Lt=1.5 m, the following parameters were collected: H=120 mm, W=8000 g, and D=55 mm. Calculations were then performed... P1=0.3+0.01×(120−80)=0.7 MPa; T1 = 2 + 0.1 × 6 = 6 s; P2=0.2+0.15×8000 / 552×1.5×0.009 / 0.008×6.9 / 7≈0.85MPa After the material is fed into the silo, the transmission system stops and the vertical slide valve is closed. High-pressure inert gas is then introduced into the sealed silo. After pressurization, the slag purging system is activated to fully purge the slag from the surface of the molten steel below the feed port. The horizontal slide valve is then opened, and the rare earth ferroalloy is precisely injected into the designated position in the molten steel under inert gas pressure. After this is completed, the horizontal slide valve is closed. After all the rare earth has been added, argon bottom blowing is performed for 10 minutes, followed by slag and steel samples from the furnace. Continuous casting then begins, with an initial casting speed of 0.8 m / min in the continuous casting crystallizer. The billet cross-sectional dimensions are 400*1200 mm. After the entire furnace casting cycle is completed, steel samples are taken from the upper and lower sections of the front, middle, and rear ends of the continuously cast billet to test the rare earth yield and compositional uniformity. As shown in Table 1, the experimental results of each embodiment indicate that after adding rare earth using the rare earth alloying feeding device and method provided by this invention, the rare earth recovery rate in the ladle reaches up to 93.1%, and the average rare earth content in the continuous casting billet reaches up to 60.06%, both significantly higher than the direct feeding method (79.3% recovery rate, 25.07 ppm average content) and the ladle pressing method (85.2% recovery rate, 39.06 ppm average content). Simultaneously, the rare earth content in the slag is only 56 ppm, indicating that this method can effectively suppress the slag-metal reaction and oxidation loss of rare earth during the addition process, significantly improving the rare earth recovery rate and maintaining the stability of the slag composition. Regarding compositional uniformity, the maximum deviation of the rare earth content in the continuous casting billet obtained by this invention is only 0.6 ppm, superior to the direct feeding method (2.55 ppm) and the ladle pressing method (1.8 ppm), and far superior to the crystallizer wire feeding method (10.5 ppm), demonstrating that this device and method can significantly improve the uniformity of rare earth element distribution in the molten steel and reduce the risk of performance fluctuations. In addition, this device can be adapted to various steel containers (such as ladles, refining furnaces, continuous casting crystallizers, etc.), significantly enhancing the equipment's versatility and on-site operational flexibility, reducing the difficulty of production line modification and replacement, and meeting the feeding needs under different steel industry production conditions.

[0066] The embodiments of the present invention aim to protect a rare earth alloy feeding device and its control method, which have the following effects: 1. By collecting the slag layer thickness in real time through online detection, and by dynamically calculating the purging pressure and purging time based on the slag layer thickness by the control component, the slag layer purging component is driven to carry out directional and precise purging of the slag layer above the preset feeding station, forming a stable slag-free channel through the slag layer. This effectively avoids rare earth additives from coming into contact with molten slag during the feeding process, significantly inhibits slag-metal reaction and oxidation loss, greatly improves the recovery rate of rare earth in molten steel, and solves the technical problem of severe rare earth loss due to slag layer coverage in the existing technology. 2. By obtaining the weight and particle size of rare earth additives in real time through online detection, and combining the preset viscosity, density and target addition depth of molten steel, the control component dynamically calculates the push pressure, which drives the pneumatic feeding component to accurately deliver the rare earth additives to the preset depth inside the molten steel through the slag-free channel. This effectively overcomes the problem that rare earth additives are stuck in the shallow surface of molten steel due to the influence of buoyancy and viscous resistance, significantly improves the uniformity of rare earth element distribution in molten steel, and solves the technical problem of large composition fluctuations caused by the uncontrollable addition position in traditional feeding methods. 3. The lifting and horizontal movement positioning of the slag layer purging component and the pneumatic feeding component are realized through the position adjustment component. The control component implements closed-loop dynamic control of the entire process of slag layer thickness detection, purging parameter calculation, feeding parameter calculation, purging execution and feeding execution. This enables the device to adaptively match the feeding requirements of different molten steel containers, different slag layer conditions and different rare earth additive specifications, significantly improving the versatility of the equipment and the flexibility of on-site operation, reducing the difficulty of production line modification and replacement, and meeting the diversified needs of rare earth feeding process in steel industrial production.

[0067] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A rare earth alloy feeding device, characterized in that, include: The slag layer thickness detection component (1), the slag layer purging component (2), the pneumatic feeding component (3), the position adjustment component (34), and the control component; The slag layer thickness detection component (1) is set at a preset position on the top of the molten steel container to obtain the real-time slag layer thickness of the top layer of molten steel inside the molten steel container. The control component is electrically connected to the slag layer thickness detection component (1), the slag layer purging component (2), the pneumatic feeding component (3), and the position adjustment component (34), respectively. The control component calculates the first real-time control parameters of the slag layer purging component (2) and the second real-time control parameters of the pneumatic feeding component (3) based on the real-time slag layer thickness, combined with the physical property parameters of the rare earth alloy additive to be added and the preset depth of the added molten steel. The control component then uses the position adjustment component (34) to drive the slag layer purging component (2) to purge the slag layer at the preset feeding position according to the first real-time control parameters, and drives the pneumatic feeding component (3) to add the rare earth alloy additive at the slag layer purging position according to the second real-time control parameters.

2. The rare earth alloy feeding device according to claim 1, characterized in that, Also includes: additive detection component (5); The additive detection component (5) is positioned at the corresponding position in the additive conveying channel of the pneumatic feeding component (3) to acquire the physical property parameters of the rare earth alloy additive to be added in real time and send them to the control component.

3. The rare earth alloy feeding device according to claim 1 or 2, characterized in that, The slag layer purging assembly (2) includes: a gas storage tank (21), an electromagnetic control valve, a pressure regulator (22), and a directional purging port (23) connected in sequence by gas paths. The control component is electrically connected to the pressure regulator (22). Based on the real-time slag layer thickness, the first air pressure value and purging time of the pressure regulator (22) outlet are calculated. Based on the first air pressure value and the purging time, the high-pressure inert gas in the gas storage tank (21) is controlled to be injected through the directional purging port (23) into the slag layer corresponding to the preset feeding station to obtain a slag-free channel penetrating the slag layer.

4. The rare earth alloy feeding device according to claim 3, characterized in that, The formula for calculating the first air pressure value is: ； in, As the reference slag layer thickness, This is the pressure increment coefficient. Real-time slag layer thickness; The formula for calculating the purging time is: ； in, This is the duration increment coefficient.

5. The rare earth alloy feeding device according to claim 1 or 2, characterized in that, The pneumatic feeding assembly (3) includes: a sealed hopper (31), a slide valve (32), an adjustable air source, and a feeding channel (33). The adjustable pressure gas source stores high-pressure inert gas to push the rare earth alloy additive; The air inlet of the sealed hopper (31) is connected to the air outlet of the adjustable pressure air source; The slide gate valve (32) is located at the air outlet of the sealed hopper (31), and the slide gate valve (32) is electrically connected to the control component; The inlet of the feeding channel (33) is connected to the air outlet of the sealed silo (31) through the slide valve (32); The control component calculates the second pressure value after the gate valve (32) is opened based on the physical property parameters of the rare earth alloy additive to be added and the preset depth of the molten steel, and adjusts the adjustable pressure source based on the second pressure value to put the rare earth alloy additive into the preset depth of the molten steel through the slag-free channel.

6. The rare earth alloy feeding device according to claim 5, characterized in that, The physical properties of the rare earth alloy additive include: additive weight and additive particle size; the second real-time control parameter includes: second gas pressure value. The formula for calculating the second air pressure value after the gate valve (32) is opened is as follows: ； in, Based on the pressure of push, For comprehensive correction factors, The viscosity of molten steel under standard conditions. The density of molten steel under standard conditions. This is the weight of the additives. For additive particle size, To preset the viscosity of molten steel, To preset the molten steel density, The preset depth for adding molten steel.

7. A control method for a rare earth alloy feeding device, characterized in that, A method for controlling a rare earth alloy feeding device as described in any one of claims 1-6 includes the following steps: The control component moves the slag layer purging component (2) and the pneumatic feeding component (3) to the preset feeding station; The slag layer thickness detection component (1) detects the real-time slag layer thickness corresponding to the preset feeding station and obtains the physical property parameters of the rare earth alloy additive to be added. The real-time slag layer thickness and the physical property parameters of the rare earth alloy additive to be added are sent to the control component. Based on the real-time slag layer thickness, the physical property parameters of the rare earth alloy additive to be added, and the preset depth of the added molten steel, calculate the first real-time control parameter for controlling the slag layer purging assembly (2) and the second real-time control parameter for controlling the pneumatic feeding assembly (3). The control component controls the slag layer blowing component (2) to blow the slag layer at the corresponding position of the preset feeding station according to the first real-time control parameters, thereby obtaining a slag-free channel that penetrates the slag layer. The control component controls the pneumatic feeding component (3) to feed the rare earth alloy additive into the molten steel through the slag-free channel to the preset depth by the control component according to the second real-time control parameters.

8. The control method for the rare earth alloy feeding device according to claim 7, characterized in that, The physical properties of the rare earth alloy additives include: additive weight and additive particle size; The first real-time control parameters include: a first air pressure value and a purging duration; The second real-time control parameter includes: the second air pressure value.

9. The control method for the rare earth alloy feeding device according to claim 8, characterized in that, The formula for calculating the first air pressure value is: ； in, As the reference slag layer thickness, This is the pressure increment coefficient. Real-time slag layer thickness; The formula for calculating the purging time is: ； in, This is the duration increment coefficient.

10. The control method for the rare earth alloy feeding device according to claim 8, characterized in that, The second real-time control parameter includes: a second air pressure value; The formula for calculating the second air pressure value is: ； in, Based on the pressure of push, For comprehensive correction factors, The viscosity of molten steel under standard conditions. The density of molten steel under standard conditions. This is the weight of the additives. For additive particle size, To preset the viscosity of molten steel, To preset the molten steel density, The preset depth for adding molten steel.

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