Preparation method and application of calcium carbide deoxidizer composite tank

Abstract

The application discloses a preparation method and application of a calcium carbide deoxidizer composite tank body, and belongs to the technical field of steelmaking and molten steel refining, and aims to solve the technical problem of poor storage stability and easy pulverization of the calcium carbide deoxidizer obtained by using a traditional preparation method during use. The preparation method comprises the following steps: step 1, preparing a sealed storage tank body; step 2, preparing a gradient function filling system; step 21, preparing a core reaction layer; step 22, coating a paraffin regulation layer on the outer surface of the core reaction layer; step 23, wrapping a fluxing and catalyzing layer on the outer surface of the paraffin regulation layer; step 24, wrapping a passivation lime layer on the outer surface of the fluxing and catalyzing layer; and step 3, sealing. After the sealing treatment, the calcium carbide deoxidizer composite tank body product is obtained. The calcium carbide deoxidizer composite tank body obtained by using the preparation method can keep good stability during storage and is not prone to pulverization, and meanwhile, excellent deoxidation performance can be achieved during use.

Description

Technical Field

[0001] This invention belongs to the field of steelmaking and steel refining technology, and particularly relates to a method for preparing and applying a composite tank for calcium carbide deoxidizer. Background Technology

[0002] In the steelmaking process, deoxidation is a crucial step affecting the purity and quality of molten steel. Calcium carbide, as a highly efficient deoxidizer, is second only to aluminum in deoxidation effectiveness, superior to silicon and manganese. It can effectively replace some of the high-priced aluminum, reducing the oxygen content in molten steel and slag, improving steel purity, promoting desulfurization reactions, and reducing the loss of refractory materials in ladles. However, calcium carbide is chemically reactive and readily reacts with moisture in the air to form acetylene gas and calcium hydroxide. This not only leads to the loss of effective components but also poses safety hazards during storage and transportation.

[0003] Existing preparation processes for calcium carbide deoxidizers mostly focus on simple physical coating; for example, calcium carbide is placed inside a metal tube, and then aluminum is poured into both ends of the metal tube to seal it, ultimately encapsulating the calcium carbide within the sealed metal tube. Because these preparation processes cannot meet the requirements for stability during transportation and storage, their large-scale industrial application is limited. Summary of the Invention

[0004] Based on the above analysis, the present invention aims to provide a method for preparing a composite tank for calcium carbide deoxidizer and its application, in order to solve the technical problem that existing methods for preparing calcium carbide deoxidizers are difficult to meet the requirements for their transportation and storage stability.

[0005] The objective of this invention is mainly achieved through the following technical solutions: On one hand, the present invention provides a method for preparing a calcium carbide deoxidizer composite tank, comprising the following steps: Step 1: Prepare the sealed storage tank body; The uncoated low-carbon steel or industrial pure iron sheet with a thickness of 0.3-0.5mm is formed into a columnar composite tank and equipped with an upper end cap to obtain a sealed storage tank body. Step 2: Prepare a gradient functional filling system; the gradient functional filling system includes: a core reaction layer, a paraffin regulating layer, a fluxing catalyst layer, and a passivated lime layer; the core reaction layer is composed of calcium carbide deoxidizer particles, and the gaps between the calcium carbide deoxidizer particles are filled with passivated lime; the paraffin regulating layer is wrapped around the outer surface of the core reaction layer; the fluxing catalyst layer is wrapped around the outer surface of the paraffin regulating layer; the passivated lime layer is wrapped around the outer surface of the fluxing catalyst layer; Step 21: Prepare the core reaction layer; Step 22: Coat the outer surface of the core reaction layer with a paraffin control layer; Step 23: Wrap a fluxing catalyst layer around the surface of the paraffin control layer; Step 24: Wrap a passivated lime layer around the surface of the fluxing catalyst layer; Step 3: Sealing and sealing; Step 31: Install the end cap; Step 32: Sealing process; After sealing, the finished product of the calcium carbide deoxidizer composite tank is obtained.

[0006] Furthermore, in step 21 above, under vibration conditions, calcium carbide deoxidizer particles are filled into a columnar mold to form a dense core reaction layer, resulting in columnar material A.

[0007] Furthermore, in step 22 above, the paraffin wax is heated and melted into a molten paraffin wax solution. The molten paraffin wax solution is then injected into a mold containing columnar material A, so that it evenly coats the surface of the core reaction layer. After cooling and solidification, a continuous and uniformly thick paraffin wax control layer is formed, resulting in columnar material B.

[0008] Further, in step 23 above, three raw materials are weighed in a weight ratio of CaCl2: Na3AlF6: Al2O3 = (1-2): (1-2): 1 to obtain a fluxing catalyst mixed powder; then, the fluxing catalyst mixed powder is uniformly coated on the surface of columnar material B to form a fluxing catalyst layer, thus obtaining columnar material C.

[0009] Further, in step 24 above, a layer of passivated lime powder with a thickness of 0.2-1 mm is first laid at the bottom of the sealed storage composite tank; then, the columnar material C prepared in step 23 is placed into the sealed storage composite tank and filled with passivated lime until it completely covers the flux layer and fills the remaining space of the composite tank. After filling, it is vibrated to form a passivated lime layer.

[0010] Furthermore, in step 21, the particle size of the calcium carbide deoxidizer particles is 5-15 mm, and the CaC2 weight content is ≥98%.

[0011] The above-mentioned method for preparing the calcium carbide deoxidizer composite tank also includes step 33, airtightness testing, and finished product packaging; After sealing, the finished composite canisters containing calcium carbide deoxidizer are sampled for airtightness testing to ensure there are no leaks. The qualified composite canisters are then placed into vacuum packaging bags and vacuum-sealed as the final outer packaging.

[0012] Furthermore, steps 2 and 3 above are both carried out in a dry, nitrogen-protected clean environment.

[0013] On the other hand, the present invention also provides a calcium carbide deoxidizer composite tank, which is prepared by the above-mentioned method for preparing a calcium carbide deoxidizer composite tank; The aforementioned calcium carbide deoxidizer composite tank includes a sealed storage tank body and a gradient functional filling system; the gradient functional filling system is filled into the sealed storage tank body; The gradient functional filling system consists of a core reaction layer, a paraffin regulating layer, a fluxing catalyst layer, and a passivated lime layer from the inside out. The core reaction layer is composed of calcium carbide deoxidizer particles, and the gaps between the calcium carbide deoxidizer particles are filled with passivated lime. The paraffin regulating layer is wrapped around the outer surface of the core reaction layer. The fluxing catalyst layer is wrapped around the outer surface of the paraffin regulating layer. The passivated lime layer is wrapped around the outer surface of the fluxing catalyst layer.

[0014] In another aspect, the present invention also provides an application of a calcium carbide deoxidizer composite tank, wherein the calcium carbide deoxidizer composite tank is prepared by the above-described method for preparing the calcium carbide deoxidizer composite tank; or, the above-described calcium carbide deoxidizer composite tank is used. The aforementioned calcium carbide deoxidizer composite tank is used in the deoxidation process of molten steel during tapping and in the refining process of steel ladle, and includes the following steps: Step 1: The calcium carbide deoxidizer composite tank is injected into the molten steel or refining slag layer using a nitrogen pulse blowing method. Step 2: The injection location is in the molten steel during tapping or in the refining slag layer, with an injection speed ≥15m / s; the injection timing is in the molten steel during the first 1 / 3 to 2 / 3 of the tapping period or in the slag layer during the initial refining stage; during the deoxidation stage of tapping, the amount added is adjusted according to the carbon content of the molten steel; during the refining stage of molten steel, a fixed amount of 0.5kg / t steel is used, and strong argon stirring is completed within 3-4 minutes after injection.

[0015] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects: (1) This invention significantly improves the stability of calcium carbide deoxidizer during storage and transportation by constructing a gradient functional filling system consisting of a core reaction layer, a paraffin regulating layer, a fluxing catalyst layer, and a passivated lime layer, combined with multiple protections of the sealed storage tank body. Specifically, the paraffin regulating layer on the surface of the core reaction layer acts as a physical barrier, effectively preventing the intrusion of external moisture; the passivated lime layer further adsorbs moisture in the environment and forms a dense structure after vibration filling, reducing internal voids. This multi-layered synergistic protection design effectively solves the problem that traditional calcium carbide deoxidizers are prone to hydration reactions with moisture in the air due to their active chemical properties, leading to loss of effective components and safety hazards, and meets the stability requirements for large-scale industrial transportation and storage.

[0016] (2) This invention provides continuous physical isolation protection for the storage, transportation and application of calcium carbide deoxidizer through a multi-layer physical isolation design of “sealed composite tank + passivated lime layer + paraffin control layer + core reaction layer”, ensuring that the reactivity of calcium carbide deoxidizer particles is not affected, solving the problems of easy hydration and easy explosion of calcium carbide deoxidizer, extending the product storage period and ensuring the safety of use.

[0017] In this invention, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this invention will be set forth in the following description, and some advantages may become apparent from the description or be learned by practicing the invention. The objects and other advantages of this invention can be realized and obtained from what is particularly pointed out in the description and drawings. Attached Figure Description

[0018] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0019] Figure 1 This is a schematic diagram of the overall structure of the calcium carbide deoxidizer composite tank of the present invention; Figure 2 This is a vertical cross-sectional view of the calcium carbide deoxidizer composite tank of the present invention; Figure 3 This is a process flow diagram of the preparation process of the calcium carbide deoxidizer composite tank of the present invention.

[0020] Figure label: 1-Composite tank body for calcium carbide deoxidizer; 2-Core reaction layer; 3-Paraffin wax control layer; 4-Fluidation catalyst layer; 5-Passivated lime layer; 6-Sealed storage tank body; 7-Upper head; 8-Lower head. Detailed Implementation

[0021] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which constitute a part of the present invention and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0022] This invention also provides a method for preparing a calcium carbide deoxidizer composite tank 1, such as... Figure 3 As shown, it includes the following steps: Specifically, such as Figure 3 As shown, the preparation method of the above-mentioned calcium carbide deoxidizer composite tank 1 includes the following steps: Step 1: Prepare the sealed storage tank body 6; Based on the design dimensions of the sealed storage tank body 6, uncoated low-carbon steel or industrial pure iron sheet with a thickness of 0.3-0.5mm (e.g., 0.3mm, 0.4mm, 0.5mm) is used to form a columnar composite tank body 1 through stamping or welding processes, and equipped with an upper end cap 7 to obtain the sealed storage tank body 6.

[0023] In step 1 above, the formed empty composite tank 1 is cleaned and dried to remove oil and moisture, and then set aside for use.

[0024] In step 1 above, the diameter of the sealed storage tank body 6 is 60-100mm (e.g., 60mm, 70mm, 90mm, 100mm), and the height-to-diameter ratio is 0.3-0.7 (e.g., 0.3, 0.5, 0.7).

[0025] In step 1 above, pre-stress grooves are processed on the inner or outer wall of the lower end cap 8 of the sealed storage tank body 6 by molding or etching.

[0026] In step 1 above, the prestressed grooves are arranged in a cross or star shape, with a depth of 30-50% (e.g., 30%, 40%, 50%) of the thickness of the lower head 8, and a groove width of 1-2 mm (e.g., 1 mm, 1.5 mm, 2 mm). The center intersection point is precisely located at the bottom geometric center.

[0027] Step 2: Prepare a gradient filling system; Step 21: Prepare core reaction layer 2; Under vibration conditions, calcium carbide deoxidizer particles are filled into a columnar mold to form a dense core reaction layer 2, resulting in columnar material A.

[0028] In step 21 above, the weight of the calcium carbide deoxidizer particles accounts for 80-93% (e.g., 1%, 2%, 4%, 5%) of the total weight of the gradient functional filling system.

[0029] Step 22: Coat the outer surface of the core reaction layer 2 with a paraffin regulating layer 3; Paraffin wax is heated and melted into a molten paraffin wax solution. The molten paraffin wax solution is then poured into a mold containing columnar material A, so that it evenly coats the surface of the core reaction layer 2. After cooling and solidification, a continuous and uniformly thick paraffin wax control layer 3 is formed, resulting in columnar material B.

[0030] In step 22 above, the amount of paraffin control layer 3 is 1-5% of the total weight of the gradient functional filler system (e.g., 1%, 2%, 3%, 4%, 5%).

[0031] In step 22 above, the thickness of the paraffin control layer 3 is 0.5-2 mm (e.g., 0.5 mm, 0.9 mm, 1.2 mm, 1.5 mm, 1.8 mm, 2 mm).

[0032] Step 23: Wrap a fluxing catalyst layer 4 around the surface of the paraffin control layer 3; In step 23, the three raw materials are accurately weighed according to the weight ratio of CaCl2: Na3AlF6: Al2O3 = (1-2): (1-2): 1. The weighed materials are mixed for ≥30 minutes to ensure that the components are evenly distributed and to obtain a homogeneous fluxing catalytic mixed powder. Then, the prepared fluxing catalytic mixed powder is evenly coated on the surface of columnar material B to form a fluxing catalytic layer 4 with a thickness of 0.5-1 mm, thus obtaining columnar material C.

[0033] In the fluxing catalyst layer 4, the particle size of the CaCl2 micro powder and Na3AlF6 micro powder is 100-200 mesh (e.g., 100 mesh, 120 mesh, 150 mesh, 180 mesh, 200 mesh), and the particle size of the Al2O3 micro powder is 210-325 mesh (e.g., 210 mesh, 250 mesh, 280 mesh, 310 mesh, 325 mesh).

[0034] In step 23 above, the amount of fluxing catalyst layer 4 is 3-8% (e.g., 3%, 5%, 6%, 8%) of the total weight of the gradient functional filling system.

[0035] Step 24: Wrap a passivated lime layer 5 around the surface of the fluxing catalyst layer 4; First, a layer of passivated lime powder with a thickness of 0.2-1 mm is laid at the bottom of the sealed storage composite tank 1. Then, the columnar material C prepared in step 23 is placed into the sealed storage composite tank 1 and filled with passivated lime until it completely covers the flux layer and fills the remaining space of the composite tank 1. After filling, a slight vibration is performed to make the lime layer 5 dense and tightly adhere to the inner wall of the composite tank 1.

[0036] In step 24 above, the amount of passivated lime layer 5 should account for 3-6% (e.g., 3%, 5%, 6%) of the total weight of the gradient functional filling system.

[0037] In step 24 above, the thickness of the passivated lime layer 5 is 0.2-1 mm (0.2 mm, 0.4 mm, 0.6 mm, 0.8 mm, 1 mm).

[0038] The above preparation process is carried out in a dry, nitrogen-protected clean environment to prevent calcium carbide and fluxing catalyst powder from getting damp.

[0039] Step 3: Sealing and sealing; Step 31: Install the end cap 7; After filling is complete, immediately install the upper end cap 7 onto the top of the composite tank 1.

[0040] Step 32: Sealing process; The upper end cap 7 is sealed tightly to the composite tank 1 by mechanical edge rolling and pressing, ensuring that the entire composite tank 1 is in a completely sealed state, isolating it from the outside humid air, and thus obtaining the finished product of the calcium carbide deoxidizer composite tank 1.

[0041] Step 33: Air tightness testing and finished product packaging; After sealing, the finished composite tank 1 is sampled and tested for air tightness to ensure there are no leaks. The qualified composite tank 1 is then placed into a vacuum packaging bag and vacuum-sealed as the final outer packaging.

[0042] On the other hand, the present invention also provides a composite tank 1 for calcium carbide deoxidizer, such as Figure 1 and Figure 2 As shown, the calcium carbide deoxidizer composite tank 1 (hereinafter referred to as composite tank 1) includes a sealed storage tank body 6 and a gradient functional filling system; the gradient functional filling system is filled inside the sealed storage tank body 6; the gradient functional filling system includes, from the inside to the outside, a core reaction layer 2, a paraffin regulating layer 3, a fluxing catalyst layer 4, and a passivated lime layer 5; wherein, the core reaction layer 2 is composed of calcium carbide deoxidizer particles; the paraffin regulating layer 3 is wrapped around the outer surface of the core reaction layer 2; the fluxing catalyst layer 4 is wrapped around the outer surface of the paraffin regulating layer 3, and the passivated lime layer 5 is wrapped around the outer surface of the fluxing catalyst layer 4.

[0043] Specifically, the core reaction layer 2 is composed of calcium carbide deoxidizer particles and is located at the center of the sealed storage tank body 6. The core reaction layer 2 reacts with oxygen in the molten steel and slag to achieve deoxidation. The core reaction layer 2 is wrapped with a paraffin wax regulating layer 3, which controls and reduces the carbon content of the molten steel during steelmaking and refining. The paraffin wax regulating layer 3 is further wrapped with a fluxing catalyst layer 4, which lowers the melting point of the reaction system during steelmaking and refining, promotes the rapid deoxidation reaction between the calcium carbide deoxidizer and the molten steel and slag, and improves deoxidation efficiency. The fluxing catalyst layer 4 is wrapped with a passivated lime layer 5. When stored in the composite tank 1, the CaO in the passivated lime layer 5 reacts with the residual moisture in the composite tank 1 (CaO + H2O → Ca(OH)2) to form a dense calcium hydroxide protective film, thereby preventing further moisture penetration into the core reaction layer 2. When in use, the passivated lime layer 5 decomposes rapidly after molten steel is added to the composite tank 1, and the released CaO can also participate in slag formation, thereby increasing the slag basicity and assisting in desulfurization.

[0044] In the aforementioned core reaction layer 2, the gaps between the calcium carbide deoxidizer particles are filled with liquid paraffin. After the liquid paraffin solidifies, it enhances the overall sealing of the core reaction layer 2, preventing moisture inside the storage sealed tank body 6 from seeping through the gaps between the particles to the surface of the calcium carbide deoxidizer particles and triggering a hydration reaction.

[0045] Compared with existing technologies, in terms of moisture protection and storage safety, this invention provides continuous physical isolation protection throughout the entire process of storing, transporting and dispensing calcium carbide deoxidizer by using a multi-layer physical isolation design consisting of "sealed composite tank 1 + passivated lime layer 5 + paraffin control layer 3 + core reaction layer 2". This ensures that the reactivity of calcium carbide deoxidizer particles is not affected, solves the problems of easy hydration and flammability / explosion of calcium carbide deoxidizer, extends the product's storage period, and ensures safe use.

[0046] The process of controlling and reducing carbon gain through the paraffin control layer 3 is as follows: When the calcium carbide deoxidizer composite tank 1 is placed into the molten pool, the material of the composite tank 1 melts and becomes part of the molten steel. In the first stage, the passivated lime layer 5 and the fluxing catalyst layer 4 inside it begin to melt, exposing the paraffin control layer 3. In the second stage, the paraffin control layer 3 is in a high-temperature environment, and the carbon in the paraffin begins to react with the oxygen in the molten steel or unstable oxides in the slag (such as FeO, MnO). The CO bubbles generated by the reaction rise to the surface (the paraffin has not reacted completely), reducing the local oxygen content in the molten steel or slag, creating a low-oxygen environment for subsequent calcium carbide deoxidation. In the third stage, as the paraffin control layer 3 is consumed and the core reaction layer 2 reaches the reaction temperature, the calcium carbide deoxidizer begins to decompose. The carbon atoms released from this decomposition need to pass through the incompletely reacted paraffin control layer 3 to enter the molten steel. The carbon-saturated boundary layer formed by the paraffin control layer 3 at high temperatures reduces the carbon activity gradient at the steel / paraffin interface, effectively slowing the diffusion flux of active carbon atoms from calcium carbide decomposition into the molten steel. Meanwhile, the calcium (vapor) from calcium carbide decomposition remains unaffected. This allows the calcium (vapor) from calcium carbide decomposition to preferentially enter the molten steel for deoxidation, while the carbon atoms are inhibited from further diffusion into the molten steel. In the fourth stage, after the deoxidation reaction is complete, the reaction products (including CaO and C residue) form low-melting-point compounds that float into the slag. It should be noted that during the refining process, this reaction will occur directly with iron oxide in the slag.

[0047] When paraffin is in a high-temperature environment, its reaction with oxygen in molten steel and slag, or unstable oxides in slag, includes the following processes: [C] + [O] → CO↑(1) C + FeO → Fe + CO↑(2) The processes described in equations (1) and (2) occur when the calcium carbide deoxidizer (CaC2) comes into contact with molten steel and slag, which consumes some oxygen in advance and reduces the deoxidation burden of the calcium carbide deoxidizer in the core reaction layer 2.

[0048] This invention utilizes the regulating effect of the paraffin layer to ensure that the release of carbon from the calcium carbide deoxidizer remains slow and controllable throughout the deoxidation process, thereby preventing instantaneous carbon increase in molten steel and slag.

[0049] Compared with the prior art, the paraffin regulating layer 3 set between the core reaction layer 2 and the fluxing catalyst layer 4 in this invention can act as a two-way regulating valve. On the one hand, it preferentially reacts with oxygen in molten steel or steel slag at the smelting temperature ([C]+[O]→CO, C+FeO→Fe+CO), creating a low-oxygen environment for subsequent calcium carbide deoxidation. On the other hand, the carbon saturated boundary layer formed by the paraffin regulating layer 3 at high temperature reduces the carbon activity gradient at the steel / paraffin interface, thereby effectively slowing down the diffusion flux of active carbon atoms generated by calcium carbide decomposition into the steel, while the calcium (vapor) generated by calcium carbide decomposition is unaffected. This allows the calcium (vapor) generated by calcium carbide decomposition to preferentially enter the steel for deoxidation, while carbon atoms are inhibited from further diffusion into the steel.

[0050] The thickness of the paraffin regulating layer 3 is 0.5-2 mm (e.g., 0.5 mm, 0.9 mm, 1.2 mm, 1.5 mm, 1.8 mm, 2 mm). If its thickness is less than 0.5 mm, its "two-way regulating valve" function is difficult to perform; it cannot effectively consume oxygen to create a low-oxygen environment, nor can it suppress carbon atom diffusion to control carbon increase in molten steel. If its thickness is greater than 2 mm, it will increase the resistance to the passage of calcium (vapor) decomposed from calcium carbide, affecting its rate and efficiency of entering the molten steel for deoxidation. Therefore, controlling the thickness of the paraffin regulating layer 3 within the range of 0.5-2 mm allows it to achieve a balance between preferential oxygen consumption, suppression of carbon increase, and ensuring the passage of calcium vapor, ensuring efficient and stable deoxidation, and controlling the impact on the composition of molten steel.

[0051] The particle size of the calcium carbide deoxidizer particles in the core reaction layer 2 is 5-15 mm (e.g., 5 mm, 8 mm, 10 mm, 15 mm). Controlling the particle size of the calcium carbide deoxidizer particles within this range ensures both storage stability and reaction controllability, guaranteeing that the calcium carbide deoxidizer reacts fully during steelmaking and refining processes, avoiding overly vigorous or delayed reactions, and achieving efficient and stable deoxidation.

[0052] In the calcium carbide deoxidizer particles in the core reaction layer 2 mentioned above, the CaC2 content is ≥98% (e.g., 98%, 99%).

[0053] Compared with existing technologies, the present invention uses high-purity calcium carbide deoxidizer particles as the deoxidation reaction material, which can ensure the high efficiency of deoxidation effect.

[0054] It should be explained that the calcium carbide deoxidizer composite tank 1 of the present invention can be used for deoxidation of molten steel during tapping and deoxidation of steel ladle refining. When molten steel is tapped, the calcium carbide deoxidizer added to the molten steel can react with the oxygen in the molten steel in the ladle to generate CO / CO2, as shown in formula (3), thereby replacing part of the expensive aluminum deoxidizer and reducing production costs. When steel ladle is refined, the calcium carbide deoxidizer added to the ladle can reduce the oxides (such as FeO, as shown in formula (4)) in the steel slag to deoxidize the steel slag, reduce the FeO content in the slag, thereby forming white slag, and thus having a high deoxidation capacity.

[0055] The deoxidation processes of calcium carbide deoxidizer during steel tapping and ladle refining are as follows: (CaC2) + 3[O] → (CaO) + 2CO↑(3) CaC2+ 3(FeO) → (CaO) + 3Fe + 2CO↑(4) The fluxing catalyst layer 4 of the present invention comprises CaCl2 micro powder, Na3AlF6 micro powder and Al2O3 micro powder.

[0056] Specifically, under steelmaking temperature conditions, CaCl2 micro powder and Na3AlF6 micro powder can dissolve in high-melting-point components (such as CaO and SiO2) in steel slag, forming low-melting-point eutectics. This reduces the viscosity of the steel slag, improves its fluidity, and provides a favorable mass transfer environment for the reaction of calcium carbide deoxidizer with oxygen in the molten steel and oxides in the steel slag. Simultaneously, Al2O3 micro powder has a high surface energy in molten steel, allowing fine oxide particles (such as CaO) generated during the deoxidation reaction to heterogeneously nucleate and aggregate on its surface, forming larger composite inclusions. These larger inclusions are more easily separated from the molten steel (slag), effectively reducing the inclusion content and improving the purity of the steel. Furthermore, Al2O3 micro powder can react with CaO to form low-melting-point calcium aluminates, further promoting inclusion removal.

[0057] Compared with the prior art, the CaCl2 micro powder, Na3AlF6 micro powder (cryolite) and Al2O3 micro powder in the fluxing catalyst layer 4 of the present invention can effectively reduce the melting point of the high melting point oxides generated by the reaction, promote the aggregation, growth and floating of inclusions, and Al2O3 micro powder can also serve as a heterogeneous nucleation core to accelerate the formation of deoxygenation products.

[0058] In the fluxing catalyst layer 4 of this invention, the weight ratio of CaCl2 micro powder: Na3AlF6 micro powder: Al2O3 micro powder is (1-2):(1-2):1 (e.g., 1:1:1, 1.5:1.5:1, 2:2:1). This weight ratio allows the strong fluxing effect of CaCl2, the improvement of slag fluidity by Na3AlF6, and the heterogeneous nucleation and inclusion aggregation promotion functions of Al2O3 to be synergistically utilized. When the ratio of CaCl2 to Na3AlF6 is within the range of (1-2):(1-2):1, the melting point and viscosity of the slag system can be effectively reduced, providing suitable kinetic conditions for the reaction; while the proportion of Al2O3 micro powder ensures that while promoting inclusion nucleation and growth, it does not increase the source of new inclusions due to excess, thereby optimizing the fluxing catalytic effect.

[0059] The thickness of the fluxing catalyst layer 4 of the present invention is 0.5-1 mm (e.g., 0.5 mm, 0.7 mm, 0.9 mm, 1 mm), which can fully encapsulate the core reaction layer 2. By controlling the thickness of the fluxing catalyst layer 4 within the above range, it is possible to achieve efficient material utilization and a rational structure of the composite tank 1 while ensuring the fluxing catalytic effect.

[0060] The particle size of the CaCl2 micro powder and Na3AlF6 micro powder is 100-200 mesh (e.g., 100 mesh, 120 mesh, 150 mesh, 180 mesh, 200 mesh), and the particle size of the Al2O3 micro powder is 210-325 mesh (e.g., 210 mesh, 250 mesh, 280 mesh, 310 mesh, 325 mesh).

[0061] It should be noted that the particle size of CaCl2 micro powder and Na3AlF6 micro powder in the above-mentioned fluxing catalyst layer 4 is 100-200 mesh, and the particle size of Al2O3 micro powder is 210-325 mesh. The purpose of controlling the particle size of the three within their respective ranges is to ensure that CaCl2 micro powder, Na3AlF6 micro powder and Al2O3 micro powder can be uniformly mixed and tightly attached to the outer surface of the core reaction layer 2 to form a continuous coating layer. When the sealed storage tank body 6 is directionally torn under the high temperature of molten steel, CaCl2 micro powder and Na3AlF6 micro powder can diffuse and penetrate into the interface between molten steel and calcium carbide deoxidizer particles, effectively reducing the surface tension of the reaction interface and promoting the contact and reaction of oxygen elements in calcium carbide and molten steel. Al2O3 micro powder (210-325 mesh), due to its finer particle size, can fill the tiny gaps between CaCl2 micro powder and Na3AlF6 micro powder particles, on the one hand enhancing the structural stability of the fluxing catalyst layer 4, and on the other hand, Al2O3 micro powder can also act as a heterogeneous nucleation core to accelerate the formation of deoxidation products.

[0062] It should be explained that although this invention introduces trace amounts of CaCl2 and Na3AlF6, since their dosage is extremely small and they mainly enter the slag, their impact on the cleanliness of the molten steel is within a controllable range after slag adsorption treatment. The residual risk can be reduced by optimizing the slag system, which will not be elaborated here.

[0063] Compared with existing technologies, the composite tank 1 of this invention, through a gradient functional filling system, can significantly improve the comprehensive performance of calcium carbide deoxidizer in steel smelting and refining processes. Firstly, the core reaction layer 2 uses calcium carbide deoxidizer particles with a particle size of 5-15mm (5mm, 8mm, 10mm, 12mm, 15mm) and fills the gaps with paraffin wax. This ensures the reactivity of calcium carbide as the core deoxidizing material while using paraffin wax to further prevent moisture intrusion, reducing pre-hydration loss of calcium carbide during storage and transportation, and ensuring that it retains a high effective content when added to molten steel. Secondly, the paraffin wax regulating layer 3 is located between the core reaction layer 2 and the fluxing catalyst layer 4. After the composite tank 1 is filled with molten steel, the passivated lime layer 5 and the fluxing catalyst layer 4 melt, exposing the paraffin wax regulating layer 3. The carbon in the paraffin wax undergoes "pre-deoxidation," consuming some oxygen and creating a low-oxygen environment for calcium carbide deoxidation. By utilizing the carbon-saturated boundary layer formed by the paraffin control layer 3 at high temperatures, the carbon activity gradient at the steel / paraffin interface is reduced, thereby effectively slowing down the diffusion flux of active carbon atoms generated by calcium carbide decomposition into the steel body 6, and preventing instantaneous carbon increase in the molten steel. Furthermore, the CaCl2 micro powder, Na3AlF6 micro powder, and Al2O3 micro powder in the fluxing catalyst layer 4 are matched in a specific ratio and particle size, and can melt rapidly in the high-temperature environment of molten steel. On the one hand, this lowers the melting point of the reaction system, promotes the contact and reaction between calcium carbide in the core reaction layer 2 and oxygen in the molten steel, and improves the deoxidation efficiency. On the other hand, Al2O3 micro powder, as a heterogeneous nucleation core, promotes the aggregation and growth of deoxidation product CaO on its surface, forming low-melting-point calcium aluminate (such as 12CaO·7Al2O3, melting point 1455℃), lowering the melting point of inclusions and improving their flotation removal kinetics. At the same time, Al2O3, CaCl2 micro powder, and Na3AlF6 micro powder synergistically reduce the melting point and viscosity of the slag system, optimizing the reaction mass transfer conditions. Finally, the outermost passivated lime layer 5 is made of highly active passivated lime, which can not only effectively isolate external humid air and moisture to prevent calcium carbide from hydrating before use, but also quickly dissolve and participate in the steel refining process after molten steel is put into the composite tank 1, without introducing additional impurities. At the same time, its alkaline properties can also assist in desulfurization and improve the quality of molten steel.

[0064] The core reaction layer 2, paraffin regulating layer 3, fluxing catalyst layer 4, and passivated lime layer 5 of this invention form a four-layer structure with progressive functions from the inside out, creating a synergistic mechanism of "deoxidation-regulation-purification-refining". This significantly improves the overall performance of calcium carbide deoxidizer and solves the technical problems of easy hydration, uncontrollable reaction, and easy carbonization in the traditional use of calcium carbide.

[0065] It should be noted that the passivated lime layer 5 of the present invention (using high-temperature calcined active lime with a CaO content ≥95%, for example, 95%, 96%, 97%) has an activity greater than 300 ml (for example, an activity of 320 ml, 330 ml, 340 ml). It can not only absorb the trace amounts of moisture that may be generated in the core reaction layer 2 and the fluxing catalyst layer 4 to prevent premature hydration of calcium carbide, but also react rapidly with harmful impurities (for example, sulfur and phosphorus) in the molten steel after the sealed storage tank body 6 is torn, playing an auxiliary role in desulfurization and dephosphorization, and achieving synergistic optimization of deoxidation and refining.

[0066] In the above-mentioned gradient functional filling system, the weight of calcium carbide deoxidizer particles in the core reaction layer 2 accounts for 80-93% of the total weight of the gradient functional filling system (e.g., 80%, 87%, 90%, 93%).

[0067] In the above-mentioned gradient functional filling system, the weight of the paraffin control layer 3 accounts for 1-5% (e.g., 1%, 2%, 4%, 5%) of the total weight of the gradient functional filling system.

[0068] In the above-mentioned gradient functional filling system, the weight of the fluxing catalyst layer 4 accounts for 3-8% (e.g., 3%, 5%, 6%, 8%) of the total weight of the gradient functional filling system.

[0069] In the above-mentioned gradient functional filling system, the weight of the passivated lime layer 5 accounts for 3-6% (e.g., 3%, 5%, 6%) of the total weight of the gradient functional filling system.

[0070] In the core reaction layer 2, the paraffin filling the gaps between the calcium carbide deoxidizer particles can prevent damage to the sealed storage tank body 6.

[0071] The thickness of the aforementioned passivated lime layer 5 is 0.2-1 mm (0.2 mm, 0.4 mm, 0.6 mm, 0.8 mm, 1 mm).

[0072] In order to enable the sealed storage tank body 6 to tear in a directional manner when it is immersed in the molten pool, the bottom of the sealed storage tank body 6 of the present invention is provided with pre-stress grooves. The pre-stress grooves are arranged in a cross shape or star shape. The pre-stress grooves can tear in a directional manner under temperature conditions of 900-1100℃ (e.g., 900℃, 1000℃, 1050℃, 1100℃).

[0073] Compared with the prior art, the present invention provides pre-stress grooves arranged in a cross or star shape at the bottom of the sealed storage tank body 6, which enables the sealed storage tank body 6 to be directionally torn under smelting temperature conditions of 900-1100℃, ensuring that the calcium carbide deoxidizer is quickly released after entering the molten pool.

[0074] The aforementioned sealed storage tank body 6 is a cylindrical body with a diameter of 60-100mm (e.g., 60mm, 70mm, 90mm, 100mm) and a height-to-diameter ratio of 0.3-0.7 (e.g., 0.3, 0.5, 0.7).

[0075] The top surface of the sealed storage tank body 6 is the upper end cap 7, and the bottom surface is the lower end cap 8. The thickness of the lower end cap 8 is greater than that of the upper end cap 7 to increase the stability of the sealed storage composite tank 1 and improve its anti-overturning ability; at the same time, it lowers the center of gravity of the composite tank 1 when it is fully loaded, forming a reasonable weight distribution.

[0076] The material of the sealed storage tank body 6 is uncoated low-carbon steel or industrial pure iron.

[0077] Compared with the prior art, the present invention uses uncoated low-carbon steel or industrial pure iron as the material of the sealed storage tank body 6. The material of the composite tank body 1 is of the same origin as the steel substrate and becomes molten steel after melting. This avoids the problem of impurity introduction caused by traditional coating metals, can achieve zero pollution, and ensure the purity of calcium carbide deoxidizer.

[0078] The wall thickness of the sealed storage tank body 6 of the present invention is 0.3-0.5 mm (e.g., 0.3 mm, 0.4 mm, 0.5 mm).

[0079] The present invention controls the thickness of the sealed storage tank body 6 to 0.3-0.5mm to ensure that the pre-stress groove can be cracked in a controlled manner, and avoids the waste of calcium carbide deoxidizer by burning on the slag layer surface.

[0080] The depth of the aforementioned prestressing grooves is 30-50% (e.g., 30%, 40%, 50%) of the wall thickness of the sealed storage tank body 6, and the groove width is 1-2 mm (e.g., 1 mm, 1.5 mm, 2 mm). The central intersection point of the cross-shaped or star-shaped arrangement is located at the geometric center of the bottom of the sealed storage tank body 6. During tapping, when the sealed storage tank body 6 is immersed in the molten steel impact zone (1 / 3-1 / 2 height from the bottom of the ladle, e.g., 1 / 3, 2 / 5, 1 / 2) into the high-temperature molten steel; or during steel refining, after being immersed in the slag, the heat is rapidly transferred through the tank wall to the prestressing grooves. Because the groove depth is 30-50% of the wall thickness, this is the weakest point of the composite tank body 1. The cross-shaped or star-shaped arrangement causes the stress to concentrate at the central intersection point (located at the geometric center of the bottom of the composite tank body 1). After the bottom of the composite tank 1 absorbs heat upon contact with molten steel or slag, the bottom reaches its thermal softening temperature first. Under the combined action of thermal stress and pre-pressure, the material at the pre-stressed groove will cause the composite tank 1 to tear directionally along the groove from the central intersection point. This directional tearing allows the composite tank 1 to open rapidly and controllably in molten steel or slag, avoiding irregular or delayed rupture. The groove width of 1-2 mm ensures a clear tear path and also ensures the structural integrity of the composite tank 1 during transportation, storage, and deployment, preventing accidental breakage. The central intersection point is at the geometric center of the bottom, causing the tear opening to expand symmetrically from the bottom center outwards, facilitating the rapid release of the gradient functional filling system within the composite tank 1.

[0081] Compared with the prior art, the present invention has the following technical effects: (1) In terms of environmental protection and economic costs, this invention uses calcium carbide, which has a lower cost, to replace part of the expensive aluminum metal as a deoxidizer, directly reducing the cost of deoxidizing materials. The composite tank body 1 is made of low-carbon steel or industrial pure iron, which is of the same origin as molten steel. After melting, it becomes part of the molten steel without the introduction of any impurities, achieving "zero pollution" green smelting. At the same time, the removal of deoxidation products also improves the overall quality of steel products.

[0082] (2) In terms of moisture protection and storage safety, the present invention provides continuous physical isolation protection throughout the entire process of storage, transportation and application of calcium carbide deoxidizer by using a multi-layer physical isolation design of “sealed composite tank 1 + passivated lime layer 5 + paraffin control layer 3 + core reaction layer 2”. This ensures that the reactivity of calcium carbide deoxidizer particles is not affected, solves the problem of calcium carbide deoxidizer being easy to hydrate and flammable and explosive, extends the product storage period, and ensures the safety of use.

[0083] (3) Regarding the timing of reactions and carbon increase control, this invention ensures that each functional component plays its role in a predetermined order during the smelting process by designing the structure of the gradient functional filling system (passivated lime layer 5 → fluxing catalyst layer 4 → paraffin regulating layer 3 → core reaction layer 2). By introducing the paraffin regulating layer 3, the dual role of carbon in paraffin as a "barrier" and "precursor" is utilized to achieve auxiliary deoxidation in the early stage while inhibiting the concentrated release of carbon during the reaction of the calcium carbide deoxidizer in the core reaction layer 2, thereby controlling the carbon increase of the molten steel.

[0084] (4) In terms of synergistic deoxidation and steel purification, the high-purity calcium carbide deoxidizer in the core reaction layer 2 of this invention can provide deep deoxidation capability; the paraffin regulating layer 3 can regulate the carbon increment; the fluxing catalyst layer 4 accelerates the removal of deoxidation products and improves the purity of molten steel by reducing the melting point and viscosity and providing heterogeneous nucleation cores; and the passivated lime layer 5 contributes to auxiliary desulfurization capability. The four work synergistically to achieve the integration of "deoxidation-regulation-purification-refining", and the comprehensive metallurgical effect is better than that of a single deoxidizer.

[0085] (5) Regarding the delivery of the composite tank 1, the present invention sets a pre-stress groove at the bottom of the storage sealed tank body 6 and combines it with a nitrogen pulse injection device to achieve directional tearing and release of the composite tank 1 in the high-temperature molten pool. This avoids the problems of uneven delivery of traditional cored wire or bulk materials, delayed reaction, and easy burning on the slag surface. It ensures that the deoxidizer acts directly on the molten steel or steel slag, and improves the utilization rate and reaction efficiency.

[0086] Furthermore, the present invention also provides a dispensing device for the aforementioned calcium carbide deoxidizer composite tank 1, used for dispensing the aforementioned calcium carbide deoxidizer composite tank 1. The dispensing device includes a nitrogen pulse injector, a carrier gas supply system, and a control unit. The nitrogen pulse injector is used to inject the aforementioned composite tank 1 into the ladle or refined steel slag in a pulse manner. The carrier gas supply system is connected to the nitrogen pulse injector and is used to provide carrier gas at a pressure of 0.4-0.6 MPa (e.g., 0.4 MPa, 0.5 MPa, 0.6 MPa). The pulse frequency of the control unit is 2-3 Hz (e.g., 2 Hz, 2.5 Hz, 3 Hz), used to inject the composite tank 1 into the ladle or refined steel slag at a speed of 15-20 m / s (15 m / s, 18 m / s, 20 m / s).

[0087] The aforementioned nitrogen pulse injector includes a launch tube, a pulse valve, and a positioning sensor; wherein, the inner diameter of the launch tube is clearance-fitted with the outer diameter of the composite tank 1, with a clearance of 0.5-1.0 mm (0.5 mm, 0.8 mm, 1.0 mm); the aforementioned pulse valve is located at the carrier gas inlet of the launch tube, with a response time of less than 50 ms; the positioning sensor is used to detect the position of the molten steel surface and the thickness of the slag layer.

[0088] The launch process is as follows: S1, composite tank 1 is launched through a nitrogen pulse injector at a pressure of 0.4-0.6MPa and a frequency of 2-3Hz; S2, composite tank 1 is injected into the molten steel or slag layer of the ladle at a speed of 15-20m / s; S3, composite tank 1 is heated in the molten steel or slag, the pre-stressed grooves are directionally torn, and the gradient filling system is released in sequence: the outer passivated lime is desulfurized first, and the calcium carbide core is deeply deoxidized.

[0089] The present invention also provides the application of the above-mentioned calcium carbide deoxidizer composite tank 1 for deoxidation during steel tapping and ladle refining.

[0090] Finally, the present invention also provides a method for using the above-mentioned calcium carbide deoxidizer composite tank 1 for deoxidation of molten steel during tapping and deoxidation of steel ladle refining, comprising the following steps: Step 1: The calcium carbide deoxidizer composite tank 1 is injected into the molten steel or refining slag layer using a nitrogen pulse blowing method. Step 2: The injection location is in the molten steel during tapping or in the refining slag layer, with an injection speed ≥15m / s; the injection timing is in the molten steel during the first 1 / 3 to 2 / 3 of the tapping period or in the slag layer during the initial refining stage; during the tapping deoxidation stage, the addition amount is adjusted according to the carbon content of the molten steel (as shown in Table 1); during the molten steel refining stage, a fixed addition amount of 0.5kg / t steel is used, and strong argon stirring is completed within 3-4 minutes after addition.

[0091] Table 1. Dosage of calcium carbide deoxidizer added during the steel tapping deoxidation stage

[0092] Preparation Example 1 Example 1 describes the preparation of a calcium carbide deoxidizer composite tank 1 with a diameter of 80 mm and a height-to-diameter ratio of 0.4. The preparation process includes the following steps: Step 1: Prepare the sealed storage tank body 6; Based on the design dimensions of the sealed storage tank body 6, a 0.4mm thick industrial pure iron sheet is used to form a columnar composite tank body 1 through stamping or welding, and an upper end cap 7 is provided to obtain the sealed storage tank body 6.

[0093] In step 1 above, pre-stress grooves are formed on the inner or outer wall of the lower end cap 8 of the sealed storage tank body 6 using molding or etching processes. The pre-stress grooves are cross-shaped, with a depth of 40% of the thickness of the lower end cap 8, i.e., a groove depth of 0.16 mm and a width of 1.5 mm, and their central intersection point is precisely located at the bottom geometric center. The formed empty composite tank body 1 is then cleaned and dried to remove oil and moisture, and is ready for use.

[0094] Step 2: Prepare a gradient filling system; Step 21: Prepare core reaction layer 2; The calcium carbide deoxidizer particles account for 87% of the total weight of the gradient functional filling system (CaC2 content ≥98%, particle size 5-15mm, uniform particle size distribution). Under vibration conditions and in a dry environment protected by nitrogen, the calcium carbide deoxidizer particles are filled into a columnar mold to form a dense core reaction layer 2, resulting in columnar material A.

[0095] Step 22: Coat the outer surface of the core reaction layer 2 with a paraffin regulating layer 3; Paraffin wax is heated and melted into a molten paraffin wax solution. The molten paraffin wax solution is then poured into a mold containing columnar material A, so that it evenly coats the surface of the core reaction layer 2. After cooling and solidification, a continuous and uniformly thick paraffin wax control layer 3 is formed, resulting in columnar material B.

[0096] In step 22 above, the amount of paraffin control layer 3 accounts for 3% of the total weight of the gradient functional filling system.

[0097] In step 22 above, the thickness of the paraffin control layer 3 is 1.2 mm.

[0098] Step 23: Wrap a fluxing catalyst layer 4 around the surface of the paraffin control layer 3; In step 23, the three raw materials are accurately weighed according to the weight ratio of CaCl2: Na3AlF6: Al2O3 = 1.5:1.5:1. The weighed materials are mixed for 45 minutes to ensure that the components are evenly distributed and to obtain a homogeneous fluxing catalytic mixed powder. Then, the prepared fluxing catalytic mixed powder is evenly coated on the surface of columnar material B to form a fluxing catalytic layer 4 with a thickness of 0.7 mm, thus obtaining columnar material C.

[0099] In step 23 above, the filling amount of the fluxing catalyst layer 4 accounts for 5% of the total weight of the gradient functional filling system; wherein, the particle size of CaCl2 micro powder and Na3AlF6 micro powder is 150 mesh, and the particle size of Al2O3 micro powder is 280 mesh.

[0100] Step 24: Wrap a passivated lime layer 5 around the surface of the fluxing catalyst layer 4; First, a layer of passivated lime powder with a thickness of 0.5 mm is laid at the bottom of the sealed storage composite tank 1. Then, columnar material C is placed into the sealed storage composite tank 1 and filled with passivated lime until it completely covers the flux layer and fills the remaining space of the composite tank 1. After filling, slight vibration is performed to make the lime layer 5 dense and tightly adhere to the inner wall of the composite tank 1. Finally, the thickness of the passivated lime layer 5 is 0.4 mm.

[0101] In step 24 above, the amount of passivated lime layer 5 should account for 5% of the total weight of the gradient functional filling system (CaO content is 97%, activity is 330ml).

[0102] The above preparation process is carried out in a dry, nitrogen-protected clean environment to prevent calcium carbide and fluxing catalyst powder from getting damp.

[0103] Step 3: Sealing and sealing; Step 31: Install the end cap 7; After filling is complete, immediately install the upper end cap 7 onto the top of the composite tank 1.

[0104] Step 32: Sealing process; The upper end cap 7 is sealed tightly to the composite tank 1 by mechanical edge rolling and pressing, ensuring that the entire composite tank 1 is in a completely sealed state and is isolated from the outside humid air.

[0105] Step 33: Air tightness testing and finished product packaging; After sealing, the finished composite tank 1 is sampled and tested for air tightness to ensure there are no leaks. The qualified composite tank 1 is then placed into a vacuum packaging bag and vacuum-sealed as the final outer packaging.

[0106] Preparation Example 2 Example 1 describes the preparation of a calcium carbide deoxidizer composite tank 1 with a diameter of 60 mm and a height-to-diameter ratio of 0.5. The preparation process includes the following steps: Step 1: Prepare the sealed storage tank body 6; Most of its contents are the same as those in Preparation Example 1, except that the sealed storage tank body 6 is made of uncoated low-carbon steel with a thickness of 0.3 mm. The pre-stress grooves are arranged in a star shape, with a depth of 30% of the thickness of the lower head 8, i.e., a groove depth of 0.09 mm and a width of 1.0 mm.

[0107] Step 2: Prepare a gradient filling system; Step 21: Prepare core reaction layer 2; This step is largely the same as in Preparation Example 1, except that the weight of the calcium carbide deoxidizer particles accounts for 90% of the total weight of the gradient functional filling system (CaC2 content ≥98%, particle size 5-15mm, uniform particle size distribution).

[0108] Step 22: Coat the outer surface of the core reaction layer 2 with a paraffin regulating layer 3; This step is largely the same as in Preparation Example 1, except that the paraffin control layer 3 accounts for 2% of the total weight of the gradient functionalized filling system. The thickness of the paraffin control layer 3 is 0.9 mm.

[0109] Step 23: Wrap a fluxing catalyst layer 4 around the surface of the paraffin control layer 3; This step is largely the same as in Preparation Example 1, except that CaCl2: Na3AlF6: Al2O3 = 1:1:1; the mixing time is 40 min; and the thickness of the fluxing catalyst layer 4 is 0.9 mm.

[0110] The filling amount of fluxing catalyst layer 4 accounts for 6% of the total weight of the gradient functional filling system; among them, the particle size of CaCl2 micro powder and Na3AlF6 micro powder is 200 mesh, and the particle size of Al2O3 micro powder is 325 mesh.

[0111] Step 24: Wrap a passivated lime layer 5 around the surface of the fluxing catalyst layer 4; This step is mostly the same as in Preparation Example 1, except that a layer of passivated lime powder with a thickness of 0.4 mm is first laid at the bottom of the sealed storage composite tank 1; and the final passivated lime layer 5 has a thickness of 0.4 mm.

[0112] In step 24 above, the amount of passivated lime layer 5 should account for 5% of the total weight of the gradient functional filling system (CaO content is 95%, activity is 320ml).

[0113] Step 3: Sealing and sealing; This step is the same as in Preparation Example 1.

[0114] Preparation Example 3 Example 1 describes the preparation of a calcium carbide deoxidizer composite tank 1 with a diameter of 100 mm and a height-to-diameter ratio of 0.3. The preparation process includes the following steps: Step 1: Prepare the sealed storage tank body 6; This step is largely the same as in Preparation Example 1, except that the sealed storage tank body 6 is made of uncoated low-carbon steel with a thickness of 0.5 mm.

[0115] In step 1 above, the prestressing groove is cross-shaped, with a depth of 50% of the thickness of the lower end cap 8, i.e., a depth of 0.25 mm and a width of 2 mm.

[0116] Step 2: Prepare a gradient filling system; Step 21: Prepare core reaction layer 2; This step is largely the same as in Preparation Example 1, except that the weight of the calcium carbide deoxidizer particles accounts for 82% of the total weight of the gradient functional filling system (CaC2 content ≥98%, particle size 5-15mm, uniform particle size distribution).

[0117] Step 22: Coat the outer surface of the core reaction layer 2 with a paraffin regulating layer 3; This step is largely the same as in Preparation Example 1, except that the paraffin control layer 3 accounts for 5% of the total weight of the gradient functionalized filling system. The thickness of the paraffin control layer 3 is 1.8 mm.

[0118] Step 23: Wrap a fluxing catalyst layer 4 around the surface of the paraffin control layer 3; This step is mostly the same as in Preparation Example 1, except that CaCl2: Na3AlF6: Al2O3 = 2:2:1; the mixing time is 50 min; and the thickness of the fluxing catalyst layer 4 is 1.0 mm.

[0119] The filling amount of the fluxing catalyst layer 4 accounts for 8% of the total weight of the gradient functional filling system; among them, the particle size of CaCl2 micro powder and Na3AlF6 micro powder is 100 mesh, and the particle size of Al2O3 micro powder is 210 mesh.

[0120] Step 24: Wrap a passivated lime layer 5 around the surface of the fluxing catalyst layer 4; This step is mostly the same as in Preparation Example 1, except that a layer of passivated lime powder with a thickness of 1.0 mm is first laid at the bottom of the sealed storage composite tank 1; and the final passivated lime layer 5 has a thickness of 1.0 mm.

[0121] The amount of passivated lime layer 5 should account for 5% of the total weight of the gradient functional filling system (CaO content is 96%, activity is 340ml).

[0122] Step 3: Sealing and sealing; This step is the same as in Preparation Example 1.

[0123] Example 1 During the tapping process of the 210t converter, the final carbon content was 0.043% and the final oxygen content was 416ppm. The target steel grade was low alloy steel. The calcium carbide deoxidizer composite tank 1 prepared in Example 1 of this invention was used for deoxidation.

[0124] Using the dispensing device of this invention, the nitrogen pressure is set to 0.5 MPa and the pulse frequency to 2.5 Hz. The composite tank 1 is injected into the impact zone of the molten steel flow at a speed of 18 m / s. The dispensing timing is when half of the steel has been tapped, with an addition rate of 1.0 kg / t of steel (according to Table 1). Then, 2.1 t of SiMn, 2.2 t of high-carbon ferromanganese, 70 kg of carbonizing agent, and 180 kg of aluminum blocks are added. Specifically, SiMn contains 20% silicon, 67% Mn, and 2% C (all by weight, the same below); high-carbon MnFe contains 66% Mn and 7% carbon; the carbonizing agent contains 90% carbon; and the aluminum blocks contain 37% aluminum. The final molten steel volume is 220 tons.

[0125] Observation of the release process of composite tank 1: After molten steel was injected into composite tank 1, it sank rapidly. Then, the pre-stress grooves at its bottom tore directionally, and the gradient filling system was released in an orderly manner. The molten steel remained calm, without violent churning or sparks, indicating that the reaction process was stable and controllable.

[0126] Results: After refining, the composition of the steel was 0.1407% C, 0.172% Si, 1.408% Mn, and 0.0384% acid-fused aluminum. Calculations showed that the carbon absorption rate during the steel alloying process was 83%, the carbon increase was only 0.0035%, the silicon absorption rate was 90%, the manganese absorption rate was 93%, and the aluminum absorption rate was 47%.

[0127] Example 2 The steel was refined using a 210t LF furnace, with SPHC steel grade and an aluminum content of 0.037% in the molten steel entering the station. The initial slag contained 7.43% FeO+MnO. The calcium carbide deoxidizer composite tank 1+aluminum deoxidizer prepared in Preparation Example 2 of this invention was used for refining and deoxidation to quickly produce white slag.

[0128] Using the feeding device of this invention, before refining and energizing, composite tank 1 is injected into the slag layer of the ladle at a fixed addition rate of 0.5 kg / t steel. Then, argon gas is turned on, and when the argon gas flow rate reaches 800 Nl / min, the lower electrode is energized. After processing for 2 minutes, 153 kg of aluminum deoxidizer is added, and after energizing for 4 minutes, the power supply is stopped, and a slag sample is taken. The FeO content in the slag decreases from the initial 7.43% to 0.28%, and slag formation is completed.

[0129] After composite vessel 1 was injected into the slag layer, the slag surface quickly became active, with a small number of bubbles escaping, but no violent splashing. After 4 minutes, the slag changed from black to typical "white slag" with good fluidity. The carbon increase in the molten steel during the refining process was only 0.0015%, which did not affect the steel composition.

[0130] Comparative Example 1 During the tapping process of the 210t converter, the final carbon content was 0.043%, the final oxygen content was 416ppm, and the target steel grade was low alloy steel; only aluminum deoxidizer was used for deoxidation.

[0131] During the tapping process, 2.1 tons of SiMn, 2.2 tons of high-carbon ferromanganese, 70 kg of carbon raiser, and 231 kg of aluminum blocks were added. The SiMn contained 20% silicon, 67% Mn, and 2% C; the high-carbon MnFe contained 66% Mn and 7% carbon; the carbon raiser contained 90% carbon; and the aluminum blocks contained 37% aluminum. The final tapping volume was 218 tons.

[0132] Results: After refining, the composition of the steel was 0.1445% C, 0.171% Si, 1.411% Mn, and 0.0396% acid-fused aluminum. Calculations showed that the absorption rate of carbon during the steel alloying process was 80%, the absorption rate of silicon was 89%, the absorption rate of manganese was 92%, and the absorption rate of aluminum was 39.6%.

[0133] Comparative Example 2 The steel was refined using a 210t LF furnace, with SPHC steel grade. The aluminum content of the molten steel entering the station was 0.046%, and the FeO+MnO content in the initial slag was 4.87%. White slag was produced by using aluminum deoxidizer alone.

[0134] The process begins with argon gas being turned on. When the argon gas flow rate reaches 800 Nl / min, the lower electrode is energized. Once the electrode reaches the stop position, 151 kg of aluminum deoxidizer is added. After energizing for 4 minutes, the power supply is stopped, and a slag sample is taken. Although the slag changes from black to "white," the FeO+MnO content in the slag is only 1.01%, therefore further processing is required. Argon gas is turned on again. When the argon gas flow rate reaches 800 Nl / min, the lower electrode is energized. After the electrode reaches the stop position, another 100 kg of aluminum deoxidizer is added. After processing for 4 minutes, a sample is taken. The FeO+MnO content in the slag is 0.57%, and slag formation is complete.

[0135] Comparative Example 3 This comparative example is basically the same as Example 1, except that this comparative example uses a composite tank 1 that does not contain the paraffin control layer 3.

[0136] Comparative Example 4 This comparative example is basically the same as Example 1, except that this comparative example uses an existing calcium carbide deoxidation block, the structure of which is: calcium carbide is covered and wrapped in a metal tube sealed at both ends to form a block.

[0137] Example 1 and Comparative Example 1 were conducted under the same converter, steel type, and endpoint conditions. Example 1 added 1 kg / t of calcium carbide deoxidizer composite tank 1 to aluminum blocks for combined deoxidation, while Comparative Example 1 only used aluminum blocks for deoxidation. Analysis of the experimental results showed that the carbon absorption rate of Example 1 was 3% higher than that of Comparative Example 1, mainly due to the carbon content in both calcium carbide and paraffin in the calcium carbide deoxidizer composite tank 1. Under the same carbon absorption rate, the carbon increase from the calcium carbide deoxidizer composite tank 1 was only 0.0035%. The Si, Mn, and Al absorption rates of Example 1 were all higher than those of the Comparative Example 1, indicating that the deoxidation effect of using calcium carbide deoxidizer composite tank 1 + aluminum blocks was higher than that of using aluminum blocks alone. Because the aluminum absorption rate was higher in Example 1, the cost of adding expensive aluminum blocks was reduced, saving 1.03 yuan / t of steel; based on an annual production of 3 million tons / year, this translates to a cost saving of 3.09 million yuan / year, significantly reducing production costs.

[0138] Example 2 and Comparative Example 2 describe the modification of slag using a calcium carbide deoxidizer composite tank 1 + aluminum deoxidizer and aluminum deoxidizer alone, respectively, under the same steel grade. The comparison shows that although the aluminum content in Comparative Example 2, using only aluminum deoxidizer, was higher than that in Example 2, while the FeO+MnO content in its slag was lower, the aluminum deoxidizer, being lighter, floated on the slag surface, and some reacted with oxygen in the air. This resulted in the first treatment not achieving the requirement of FeO+MnO < 1%, necessitating a second treatment and ultimately affecting the processing cycle. Example 2, using the dispensing device of this invention, injects the calcium carbide deoxidizer composite tank 1 into the ladle slag layer before refining energization, ensuring the calcium carbide deoxidizer reacts fully with the steel slag without contacting air, improving the deoxidation effect, reducing carbon gain, and shortening the processing cycle. Example 2 reduced the cost by 2.18 yuan / ton of steel compared to Comparative Example 2. Based on an annual production of 3 million tons / year, this translates to a cost saving of 6.54 million yuan / year, significantly reducing production costs.

[0139] The initial conditions of the steel grade, the carbon content of the steel (0.045%), and the amount added (1.5 kg / t steel) were kept consistent in the three groups of experiments: Example 1, Comparative Example 3, and Comparative Example 4.

[0140] Table 2 Comparison of application of Example 1, Comparative Example 3 and Comparative Example 4

[0141] Comparative experimental data shows that the present invention is significantly superior to traditional calcium carbide particles (Comparative Example 4) in four aspects: storage safety, deoxidation efficiency, carbonization control, and reaction stability. Compared with the composite tank 1 without the paraffin control layer 3 (Comparative Example 3), Example 1 of the present invention achieves better deoxidation effect while maintaining similar storage safety. In particular, the ability to control carbonization in molten steel is significantly improved, fully demonstrating the key role of the paraffin control layer 3 as a "two-way regulating valve" and realizing the synergistic effect of integrated "deoxidation-control-purification-refining".

[0142] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing a composite tank containing calcium carbide deoxidizer, characterized in that, Includes the following steps: Step 1: Prepare the sealed storage tank body; The uncoated low-carbon steel or industrial pure iron sheet with a thickness of 0.3-0.5mm is formed into a columnar composite tank and equipped with an upper end cap to obtain a sealed storage tank body. Step 2: Prepare a gradient functional filling system; the gradient functional filling system includes: a core reaction layer, a paraffin regulating layer, a fluxing catalyst layer, and a passivated lime layer; the core reaction layer is composed of calcium carbide deoxidizer particles, and the gaps between the calcium carbide deoxidizer particles are filled with passivated lime; the paraffin regulating layer is wrapped around the outer surface of the core reaction layer; the fluxing catalyst layer is wrapped around the outer surface of the paraffin regulating layer; the passivated lime layer is wrapped around the outer surface of the fluxing catalyst layer; Step 21: Prepare the core reaction layer; Step 22: Coat the outer surface of the core reaction layer with a paraffin control layer; Step 23: Wrap a fluxing catalyst layer around the surface of the paraffin control layer; Step 24: Wrap a passivated lime layer around the surface of the fluxing catalyst layer; Step 3: Sealing and sealing to obtain the finished product of the calcium carbide deoxidizer composite tank.

2. The method for preparing the calcium carbide deoxidizer composite tank according to claim 1, characterized in that, In step 21, under vibration conditions, calcium carbide deoxidizer particles are filled into a columnar mold to form a dense core reaction layer, resulting in columnar material A.

3. The method for preparing the calcium carbide deoxidizer composite tank according to claim 2, characterized in that, In step 22, paraffin wax is heated and melted into a molten paraffin wax solution. The molten paraffin wax solution is then injected into a mold containing columnar material A, so that it evenly coats the surface of the core reaction layer. After cooling and solidification, a continuous and uniformly thick paraffin wax control layer is formed, resulting in columnar material B.

4. The method for preparing the calcium carbide deoxidizer composite tank according to claim 3, characterized in that, In step 23, three raw materials are weighed in a weight ratio of CaCl2: Na3AlF6: Al2O3 = (1-2): (1-2): 1 to obtain a fluxing catalytic mixed powder; then, the fluxing catalytic mixed powder is uniformly coated on the surface of columnar material B to form a fluxing catalytic layer, thus obtaining columnar material C.

5. The method for preparing the calcium carbide deoxidizer composite tank according to claim 4, characterized in that, In step 24, a layer of passivated lime powder with a thickness of 0.2-1 mm is first laid at the bottom of the sealed storage composite tank. Then, the columnar material C prepared in step 23 is placed into the sealed storage composite tank and filled with passivated lime until it completely covers the flux layer and fills the remaining space of the composite tank. After filling, it is vibrated to form a passivated lime layer.

6. The method for preparing the calcium carbide deoxidizer composite tank according to claim 2, characterized in that, In step 21, the calcium carbide deoxidizer particles have a particle size of 5-15 mm and a CaC2 weight content of ≥98%.

7. The method for preparing the calcium carbide deoxidizer composite tank according to claim 1, characterized in that, Step 3 includes airtightness testing and finished product packaging; After sealing, the finished composite canisters containing calcium carbide deoxidizer are sampled for airtightness testing to ensure there are no leaks. The qualified composite canisters are then placed into vacuum packaging bags and sealed under vacuum as the final outer packaging.

8. The method for preparing the calcium carbide deoxidizer composite tank according to claim 1, characterized in that, Both steps 2 and 3 are performed in a dry, nitrogen-protected clean environment.

9. A composite tank for calcium carbide deoxidizer, characterized in that, The composite tank for calcium carbide deoxidizer as described in any one of claims 1 to 8 was prepared. The calcium carbide deoxidizer composite tank includes a sealed storage tank body and a gradient functional filling system; the gradient functional filling system is filled in the sealed storage tank body; The gradient functional filling system comprises, from the inside out, a core reaction layer, a paraffin regulating layer, a fluxing catalyst layer, and a passivated lime layer; wherein, the core reaction layer is composed of calcium carbide deoxidizer particles, and the gaps between the calcium carbide deoxidizer particles are filled with passivated lime; the paraffin regulating layer is wrapped around the outer surface of the core reaction layer; the fluxing catalyst layer is wrapped around the outer surface of the paraffin regulating layer; and the passivated lime layer is wrapped around the outer surface of the fluxing catalyst layer.

10. An application of a composite tank for calcium carbide deoxidizer, characterized in that, The calcium carbide deoxidizer composite tank is prepared by the method for preparing the calcium carbide deoxidizer composite tank according to any one of claims 1 to 8; or, the calcium carbide deoxidizer composite tank according to claim 9 is used. The calcium carbide deoxidizer composite tank is used for steel tapping deoxidation and ladle refining deoxidation processes, including the following steps: Step 1: The calcium carbide deoxidizer composite tank is injected into the molten steel or refining slag layer using a nitrogen pulse blowing method. Step 2: The injection location is in the molten steel during tapping or in the refining slag layer, with an injection speed ≥15m / s; the injection timing is in the molten steel during the first 1 / 3 to 2 / 3 of the tapping period or in the slag layer during the initial refining stage; during the deoxidation stage of tapping, the amount added is adjusted according to the carbon content of the molten steel; during the refining stage of molten steel, a fixed amount of 0.5kg / t steel is used, and strong argon stirring is completed within 3-4 minutes after injection.

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