Method for controlling aluminum content in ferrovanadium alloy and ferrovanadium alloy

Abstract

The application discloses a method for controlling the content of aluminum in ferrovanadium alloy, comprising the following steps: calculating the effective oxygen content according to the total content of vanadium oxide, the total content of potassium and sodium, the content of sulfur element and the content of oxygen in volatile sulfur dioxide in the reaction raw materials; calculating the corrected reference aluminum distribution factor according to the effective oxygen content and the reference aluminum distribution formula; calculating the distribution amount according to the demand of preparing ferrovanadium alloy by electric aluminum thermal reaction, wherein the aluminum distribution amount is determined according to the corrected reference aluminum distribution factor; weighing each raw material and mixing the raw materials to obtain a mixture; smelting the mixture by electric smelting; refining; air cooling, disassembling the furnace, removing the alloy cake and water quenching after the refining is completed; crushing and finishing the alloy cake to obtain the ferrovanadium alloy. The application also provides the ferrovanadium alloy prepared by the method. The method can stably control the content of aluminum in the alloy.

Description

Technical Field

[0001] This invention relates to the field of ferrovanadium alloy production technology, and more specifically to a ferrovanadium alloy smelting method and ferrovanadium alloy for improving vanadium yield. Background Technology

[0002] Ferrovanadium is the most produced vanadium product, accounting for over 70% of the final vanadium usage. It is an important alloying additive in the steel industry. Vanadium improves the strength, toughness, heat resistance, and ductility of steel. Ferrovanadium is commonly used in the production of carbon steel, low-alloy steel, high-strength steel, high-alloy steel, tool steel, and cast iron.

[0003] National standards impose strict requirements on the aluminum content in ferrovanadium alloys. Generally, the batching process control has the greatest impact on the aluminum content of ferrovanadium alloys. Typically, the aluminum content in ferrovanadium alloys is required to be below 2.0%; otherwise, quality disputes will arise, affecting product sales and use. Therefore, it is crucial to stably control the aluminum content in ferrovanadium alloys while ensuring the ferrovanadium smelting yield. Currently, some technologies reduce the aluminum content by adding a aluminum-reducing agent in the later stages of smelting, but this method is costly. Other methods use electrosilicic thermal reduction at the end of smelting instead of electroalluminothermic reduction to control the aluminum content in the alloy; similarly, this method is costly, requires multiple smelting equipment, and has low production efficiency.

[0004] Therefore, it is urgent to develop a new method to achieve stable control of aluminum content in ferrovanadium alloys and fundamentally solve these problems. Summary of the Invention

[0005] The purpose of this invention is to provide a method for controlling the aluminum content in ferrovanadium alloys and ferrovanadium alloys to solve at least one of the above-mentioned problems existing in the prior art.

[0006] To achieve the above-mentioned technical objectives, the technical solution adopted by the present invention is as follows:

[0007] According to one aspect of the present invention, a method for controlling the aluminum content in ferrovanadium alloys is provided, the method comprising the following steps:

[0008] Step S1: Calculate the effective oxygen content based on the total vanadium content, total potassium and sodium content, sulfur element, and oxygen content in volatile sulfur dioxide in the reaction raw materials;

[0009] Step S2: Calculate the corrected baseline aluminum content factor based on the effective oxygen content and baseline aluminum content formula obtained in Step S1;

[0010] Step S3: Calculate the amount of raw materials according to the type of ferrovanadium alloy to be prepared and the requirements for preparing ferrovanadium alloy by electroaluminothermic reaction, wherein the amount of aluminum is determined according to the modified reference aluminum factor calculated in step S2.

[0011] Step S4: Weigh vanadium oxide, aluminum, iron and lime according to the amount of ingredients calculated in step S3, mix the raw materials evenly to obtain a mixture;

[0012] Step S5: Add the mixture to a smelting furnace and smelt it by electricity;

[0013] Step S6: Refining is carried out after smelting is completed;

[0014] Step S7: After refining, air cool. When the surface temperature of the corundum slag meets the requirements, dismantle the furnace, remove the alloy cake, and water quench it.

[0015] Step S8: Crush and refine the alloy cake to obtain the vanadium-iron alloy.

[0016] According to one embodiment of the present invention, in step S1, the vanadium oxide is at least one of vanadium trioxide and vanadium pentoxide.

[0017] According to an embodiment of the present invention, in step S1, the effective oxygen content Q is calculated as follows:

[0018] Q = 1 - ABC

[0019] Where A is the total vanadium content in vanadium oxide, B is the total potassium and sodium content in vanadium oxide, and C is the sum of the sulfur content in vanadium oxide and the oxygen content carried by the volatilization in the form of sulfur dioxide.

[0020] According to an embodiment of the present invention, in step S2, the calculation method for the corrected reference aluminum factor D is as follows:

[0021] D = 1.125Q = 1.125(1-ABC).

[0022] According to one embodiment of the present invention, the ferrovanadium alloy is FeV50 or FeV80.

[0023] According to one embodiment of the present invention, in step S5, the mixture is added to the smelting furnace at once or in batches.

[0024] According to one embodiment of the present invention, in step S6, the depleted material is ball-milled iron particles and aluminum pellets.

[0025] According to one embodiment of the present invention, in step S4, 70% to 80% of the lime amount is first mixed with other raw materials, and in step S6, the remaining lime is added at the end of the refining process.

[0026] According to one embodiment of the present invention, in step S6, after the slag reduction is enhanced by energizing for 15 to 35 minutes, the remaining lime is added.

[0027] According to another aspect of the present invention, a vanadium-iron alloy with low aluminum content is provided, which is prepared by the above-described method.

[0028] By employing the above technical solutions, the method for controlling the aluminum content in ferrovanadium alloys and the ferrovanadium alloys provided by the present invention have at least one of the following beneficial effects compared with the prior art:

[0029] (1) Based on the chemical composition analysis and microstructure analysis of vanadium oxide, the method of the present invention proposes countermeasures to address the problems of inaccurate batching caused by the quality fluctuation of vanadium trioxide and flake vanadium and the large fluctuation of aluminum content in the alloy caused by the incomplete flotation of alumina inclusions. Based on clarifying the occurrence state of oxygen element in vanadium oxide and the thermodynamic reaction behavior of different oxides with aluminum reducing agent, the influence of components that do not participate in the aluminothermic reaction and are easily volatile on the amount of aluminum is eliminated as much as possible, and more accurate aluminum batching operation is achieved, so that the aluminum content in the alloy is effectively controlled (less than 0.50%), which meets the national standard requirements and the requirements for stable aluminum content in production.

[0030] (2) Add some lime as a covering agent at the end of refining to carry out flux addition, improve the slag’s ability to absorb and dissolve alumina inclusions, and reduce the aluminum content in alumina inclusions in ferrovanadium alloys.

[0031] (3) The obtained vanadium-iron alloy is of good quality, with no obvious alumina inclusions under 500x magnification, and the vanadium smelting yield is higher than 98%;

[0032] (4) This method is low in cost and high in efficiency, and is especially suitable for smelting low-aluminum-content ferrovanadium products using vanadium trioxide as the main raw material. Attached Figure Description

[0033] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the following detailed description to explain the invention, but do not constitute a limitation thereof. In the drawings:

[0034] Figure 1 A flowchart illustrating a method for controlling the aluminum content in ferrovanadium alloys according to an embodiment of the present invention;

[0035] Figure 2 The image shows the microstructure of the FeV80 alloy obtained according to the vanadium-iron alloy smelting method of Comparative Example 1.

[0036] Figure 3 The image shows the microstructure of the FeV80 alloy obtained according to the vanadium-iron alloy smelting method of Example 1. Detailed Implementation

[0037] The specific embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit this disclosure.

[0038] Furthermore, the reference to "embodiment" herein means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0039] The aluminothermic process for producing ferrovanadium uses aluminum as a reducing agent. A small portion of the mixed charge (a mixture of vanadium oxide, aluminum powder, and iron powder in a specific ratio) is first added to the reactor and ignited using electrodes of an electric furnace or with metallic magnesium. Once the reaction begins, the remaining charge is added continuously. At high temperatures, the vanadium oxide is reduced to metallic vanadium, which then combines with molten iron to form a ferrovanadium alloy with a high vanadium content.

[0040] Aluminum acts as a reducing agent in the reaction and generates a large amount of heat. Generally speaking, a reasonable aluminum ratio, increasing the amount of aluminum in the thermite reaction, can ensure a complete and sufficient reaction, achieving a higher direct recovery rate of vanadium. However, when the amount of aluminum exceeds a certain limit, the excess aluminum will enter the alloy, causing the aluminum content in the alloy to exceed the standard and fail to meet product quality requirements.

[0041] Vanadium trioxide and vanadium pentoxide are the main raw materials required for ferrovanadium smelting. Due to the unstable TV (total vanadium) content during the preparation of vanadium trioxide and vanadium pentoxide, low-grade vanadium oxides (TV < 64%) are often produced. According to the traditional batching model, batching and smelting often leads to excessive aluminum content in the alloy. After in-depth research and microscopic analysis, the inventors realized that the traditional batching model failed to reflect the reaction behavior and direction of each element in vanadium oxides. In particular, it did not fully consider the volatile components in vanadium oxides and the oxygen content carried by SO2 from the decomposition and volatilization of sulfates. This led to inaccurate values ​​when batching according to chemical reaction stoichiometry. Especially when using low-grade vanadium trioxide, a lot of unnecessary metallic aluminum was often added, increasing the risk of excessive Al content in the alloy. At the same time, further analysis showed that the aluminum content in ferrovanadium alloys mainly consists of two parts: (1) aluminum in the form of metal dissolved in V-Fe alloys; (2) aluminum in the form of alumina inclusions in the alloy. Therefore, to stably control the aluminum content in ferrovanadium alloys, it is necessary to start from these aspects.

[0042] The method for controlling the aluminum content in ferrovanadium alloys of this invention firstly, based on a clear understanding of the occurrence state of oxygen in vanadium oxides and the thermodynamic reaction behavior of different oxides with aluminum reducing agents, minimizes the influence of volatile components that do not participate in the aluminothermic reaction on the amount of aluminum added. Specifically, the total vanadium content (A), the total potassium and sodium content (B), and the sum (C) of sulfur in vanadium oxides and oxygen carried by sulfur dioxide volatilization are calculated according to formula 1-ABC. These parameters serve as important parameters for correcting the batching model. In the aluminum batching model of this invention, the corrected benchmark aluminum factor (D) is the mass ratio of the theoretical aluminum amount obtained from chemical reaction stoichiometry to the vanadium oxides, D = 1.125 (1-ABC). Based on this, batching, mixing, feeding, and electro-smelting are carried out.

[0043] Figure 1 A flowchart of a method for controlling the aluminum content in ferrovanadium alloys according to the present invention is shown. The method of the present invention will be described in detail below with reference to this flowchart.

[0044] The method for controlling the aluminum content in ferrovanadium alloys according to the present invention generally includes the following steps:

[0045] Step S1: Calculate the effective oxygen content based on the total vanadium content, total potassium and sodium content, sulfur element, and oxygen carried by volatilization in the form of sulfur dioxide in the vanadium oxide in the reaction raw materials;

[0046] Step S2: Calculate the corrected baseline aluminum content factor based on the effective oxygen content and baseline aluminum content formula obtained in Step S1;

[0047] Step S3: Calculate the amount of raw materials according to the type of ferrovanadium alloy to be prepared and the requirements for preparing ferrovanadium alloy by electroaluminothermic reaction. The amount of aluminum is determined according to the corrected reference aluminum factor calculated in step S2.

[0048] Step S4: Weigh vanadium oxide, aluminum, iron and lime according to the amount of ingredients calculated in step S3, mix the raw materials evenly to obtain a mixture;

[0049] Step S5: Add the mixture to the smelting furnace and smelt it by electricity;

[0050] Step S6: Refining is carried out after smelting is completed;

[0051] Step S7: After refining, air cool. When the surface temperature of the corundum slag meets the requirements, dismantle the furnace, remove the alloy cake, and water quench it.

[0052] Step S8: Crush and refine the alloy cake to obtain ferrovanadium alloy.

[0053] The following is a detailed explanation of the specific steps involved.

[0054] In step S1, the available oxygen content is calculated based on the total vanadium content, total potassium and sodium content, sulfur content, and volatile sulfur oxide content in the vanadium oxides of the reaction raw materials. Available oxygen refers to the portion of oxygen that participates in the redox reaction of aluminum in the aluminothermic reaction and consumes aluminum. Vanadium oxides can typically be at least one of vanadium trioxide and vanadium pentoxide. In some embodiments, the vanadium oxide is vanadium trioxide. The available oxygen content Q is calculated as follows:

[0055] Q = 1 - ABC (1)

[0056] Where A represents the total vanadium content in the vanadium oxide, B represents the total potassium and sodium content in the vanadium oxide, and C represents the sum of sulfur content and oxygen content carried by volatilization in the form of sulfur dioxide in the vanadium oxide. In this operation, the total vanadium content, the total potassium and sodium content, the sulfur content, and the oxygen content carried by volatilization in the form of sulfur dioxide can be measured using any method known in the art.

[0057] In step S2, the corrected baseline aluminum blending factor is calculated based on the effective oxygen content and the baseline aluminum blending formula obtained in step S1. The calculation method for the corrected baseline aluminum blending factor D is as follows:

[0058] D=1.125Q=1.125(1-ABC)Equation (2).

[0059] In step S3, the amount of raw materials is calculated according to the type of ferrovanadium alloy to be prepared and the requirements for preparing the ferrovanadium alloy by electroaluminothermic reaction. The amount of aluminum is determined according to the corrected reference aluminum factor calculated in step S2. In some embodiments, the ferrovanadium alloy to be prepared is FeV50 or FeV80. FeV50 is a ferrovanadium alloy with a V content of 48% to 55%, and FeV80 is a ferrovanadium alloy with a V content of 78% to 82%. The iron-vanadium ratio in the mixture is set according to the national standard requirements for FeV50 or FeV80 composition. The amount of aluminum is equal to the product of the mass of vanadium oxide and the corrected reference aluminum factor D.

[0060] In step S4, vanadium oxide, metallic aluminum, metallic iron, and lime are weighed according to the quantities calculated in step S3, and the raw materials are mixed evenly to obtain a mixture. If a batch feeding method is used in subsequent steps, the batching is divided into several stages according to the process requirements, each required by the proportion, and then mixed separately according to the usage of each proportion, and placed into the respective material tanks for each batch to await use. If a one-time feeding method is used in subsequent steps, the batching is carried out in one go according to the conventional proportion of the target product. In some embodiments, in this operation, only a portion of the lime (e.g., 70% to 80% of the total lime usage) is added, and the remaining 20% ​​to 30% of the lime is added at the end of the refining process.

[0061] In step S5, the mixture is added to a smelting furnace and smelted under electric current. The mixture can be added to the furnace all at once or in batches. An electric furnace, such as a straight-tube furnace, is used, with the refractory lining made of magnesia, magnesia clay, and brine. The furnace charge is ensured to be evenly distributed within the furnace, preventing accumulation in one area and excessively rapid reaction. Under optimal furnace conditions and with sufficient reaction time, smelting is carried out for 20-25 minutes. During this period, aluminothermic reduction occurs, reducing vanadium oxides to metallic vanadium.

[0062] In step S6, after smelting, refining is carried out. After slag reduction is enhanced by electric current, the remaining lime is added as a covering agent. The lime is evenly distributed into the furnace at the end of the refining process. The straight-tube furnace is then sent to the refining station for further removal of residual vanadium from the slag using a refining injection process, achieving the purpose of vanadium removal. The refining lean feed consists of ball-milled iron particles and aluminum pellets. During refining, after slag reduction is enhanced by electric current for 15-35 minutes, lime is added as a covering agent. 20%-30% of the lime is concentrated and evenly distributed at the end of the refining process while the furnace body or the feeding pipe is rotating. Adding a portion of the lime as a covering agent at the end of the refining process is a flux addition, which improves the slag's absorption and dissolution capacity for alumina inclusions and reduces the aluminum content in the alumina inclusion state in the ferrovanadium alloy.

[0063] In step S7, the refined alloy liquid is air-cooled. When the surface temperature of the corundum slag meets the requirements, the furnace is dismantled, the alloy cake is removed, and water quenching is performed. This step can be performed using conventional procedures in the art. For example, the corundum slag and the alloy are air-cooled together in the furnace. Due to the significant difference in specific gravity, the alloy and slag automatically separate into strata in the molten state. When the surface temperature of the corundum slag is detected by a temperature measuring gun to be 300~500℃, the furnace is dismantled, the alloy cake is removed, and water quenching is performed.

[0064] In step S8, the alloy cake is crushed and refined to obtain ferrovanadium alloy.

[0065] Other process parameters not described in detail in the above methods, such as smelting voltage, current, furnace body tying method, ignition method, etc., can all adopt operating parameters and information known in the art.

[0066] The present invention also provides a vanadium-iron alloy with low aluminum content, which is prepared according to the above method.

[0067] The following are specific embodiments of the method for controlling the aluminum content in ferrovanadium alloys according to the present invention. Unless otherwise stated, the raw materials, equipment, consumables, etc. used in the following embodiments can be obtained through conventional commercial means.

[0068] For the parts involving numerical ranges, those skilled in the art can choose any value within the numerical range defined by this invention according to actual needs, and are not limited to the values ​​listed in the specific embodiments. In the method of this invention, unless otherwise specified, ratios, contents, etc., all refer to mass percentages.

[0069] Example 1

[0070] In this embodiment, FeV80 was prepared using vanadium trioxide as the vanadium source.

[0071] Tests and analysis determined that the total TV content (A) in vanadium trioxide (vanadium trioxide) is 61.24%, the total K and Na content (B) is 5.72%, and the total sulfur content and oxygen carried by it in the form of SO2 (C) is 2.51%. The effective oxygen content was calculated using a modified model, with the formula 1-ABC=30.53%. Based on this, the modified baseline aluminum blending factor (D) was calculated as 1.125(1-ABC)=34.346%, resulting in a baseline aluminum blending amount of 343.46 kg per ton of vanadium trioxide. According to the national standard FeV80 (V content approximately 80%, Fe content approximately 20%), the amounts of metallic iron and lime were calculated. The process involves batching (using 80% lime), mixing, feeding, and electro-smelting. The refined lean material consists of ball-milled iron particles and aluminum pellets. After 15 minutes of electro-smelting to enhance slag reduction, the remaining 20% ​​lime is added as a covering agent. After smelting, the corundum slag and alloy are air-cooled together in the furnace. When the surface temperature of the corundum slag reaches 500°C using a temperature measuring gun, the furnace is dismantled, the alloy cake is removed and water-quenched, and then crushed and refined to obtain ferrovanadium alloy.

[0072] Example 2

[0073] In this embodiment, FeV80 was prepared using vanadium trioxide as the vanadium source.

[0074] Tests and analysis determined that the total TV content (A) of vanadium trioxide (vanadium trioxide) is 62.83%, the total K and Na content (B) is 4.15%, and the total sulfur content and oxygen carried by it in the form of SO2 (C) is 1.75%. Using a modified model, the effective oxygen content was calculated as 1-ABC=31.27%. Based on the modified model, the baseline aluminum content factor (D) was calculated as 1.125(1-ABC)=35.179%, resulting in a baseline aluminum content of 351.79 kg per ton of vanadium trioxide. Based on the national standard FeV80 (V content approximately 80%, Fe content approximately 20%), the amounts of metallic iron and lime were calculated. The process involves batching (using 70% lime), mixing, feeding, and electro-smelting. The refined lean material consists of ball-milled iron particles and aluminum pellets. After 35 minutes of electro-smelting to enhance slag reduction, the remaining 30% lime is added as a covering agent. After smelting, the corundum slag and alloy are air-cooled together in the furnace. When the surface temperature of the corundum slag reaches 300°C using a temperature measuring gun, the furnace is dismantled, the alloy cake is removed and water-quenched, and then crushed and refined to obtain ferrovanadium alloy.

[0075] Example 3

[0076] In this embodiment, FeV80 was prepared using vanadium trioxide as the vanadium source.

[0077] Tests and analysis determined that the total TV content (A) of vanadium trioxide (vanadium trioxide) is 60.38%, the total K and Na content (B) is 7.39%, and the total sulfur content and oxygen carried by it in the form of SO2 (C) is 3.32%. The effective oxygen content was calculated using a modified model, with the formula 1-ABC=28.91%. Based on the aluminum blending model, the modified baseline aluminum blending factor (D) was calculated as 1.125(1-ABC)=32.524%, resulting in a baseline aluminum blending amount of 325.24 kg per ton of vanadium trioxide. Based on the national standard FeV80 composition requirements (V content approximately 80%, Fe content approximately 20%), the amounts of metallic iron and lime were calculated. The process involves batching (using 75% lime), mixing, feeding, and electro-smelting. The refined lean material consists of ball-milled iron particles and aluminum pellets. After 30 minutes of electro-smelting to enhance slag reduction, the remaining 25% lime is added as a covering agent. After smelting, the corundum slag and alloy are air-cooled together in the furnace. When the surface temperature of the corundum slag reaches 400°C using a temperature measuring gun, the furnace is dismantled, the alloy cake is removed and water-quenched, and then crushed and refined to obtain ferrovanadium alloy.

[0078] Comparative Example 1

[0079] The comparative example uses the same raw materials and target product as Example 1.

[0080] The TV content (A) of vanadium trioxide is 61.24%, the total K and Na content (B) is 5.72%, and the total sulfur content and oxygen carried by it in the form of SO2 (C) is 2.51%. The effective oxygen content was calculated using a traditional batching model: 1-A = 38.76%. Based on this, the baseline aluminum content (D0) was calculated as 1.125(1-A) = 43.605%, resulting in a baseline aluminum content of 436.05 kg per ton of vanadium trioxide. Following this, batching, mixing, feeding, and electro-smelting were carried out according to conventional batching coefficients. The refined lean material consisted of ball-milled iron particles and aluminum pellets. After 15 minutes of enhanced slag reduction via electro-smelting, no lime was added as a covering agent. After smelting, the corundum slag and alloy were air-cooled together in the furnace. When the surface temperature of the corundum slag reached 500℃ using a thermometer, the furnace was dismantled, the alloy cake was removed, and water-quenched. The alloy cake was then crushed and refined to obtain ferrovanadium alloy.

[0081] Comparative Example 2

[0082] The raw materials and target product of this comparative example are the same as those of Example 2.

[0083] The TV content (A) in vanadium trioxide is 62.83%. Based on the traditional batching model, the effective oxygen content is calculated as 1-A=37.17%. The baseline aluminum content is calculated using the traditional model: D0=1.125(1-A)=41.816%. Therefore, the baseline aluminum content per ton of vanadium trioxide is 418.16 kg. Based on this, batching, mixing, feeding, and electro-smelting are carried out according to conventional batching coefficients. The refined lean material consists of ball-milled iron particles and aluminum pellets. After 35 minutes of enhanced slag reduction via electro-smelting, no lime is added as a covering agent. After smelting, the corundum slag and alloy are air-cooled together in the furnace. When the surface temperature of the corundum slag reaches 300℃ using a temperature measuring gun, the furnace is dismantled, the alloy cake is removed, and water quenched. The alloy cake is then crushed and refined to obtain ferrovanadium alloy.

[0084] Comparative Example 3

[0085] The raw materials and target product of this comparative example are the same as those of Example 3.

[0086] The TV content (A) in vanadium trioxide is 60.38%. Based on the traditional batching model, the effective oxygen content is calculated as 1-A=39.62%. The baseline aluminum content is calculated as D0=1.125(1-A)=44.5725%, resulting in a baseline aluminum content of 445.725 kg per ton of vanadium trioxide. Based on this, batching, mixing, feeding, and electro-smelting are carried out according to conventional batching coefficients. The refining material consists of ball-milled iron particles and aluminum pellets. After 30 minutes of enhanced slag reduction via electro-smelting, no lime is added as a covering agent. After smelting, the corundum slag and alloy are air-cooled together in the furnace. When the surface temperature of the corundum slag reaches 400℃ using a temperature measuring gun, the furnace is dismantled, the alloy cake is removed, and water quenched. The alloy cake is then crushed and refined to obtain ferrovanadium alloy.

[0087] The aluminum content and TV (total vanadium) content in the vanadium-iron alloys of Examples 1-3 and Comparative Examples 1-3 were tested, and their microstructures were observed. The results are shown in Table 1 below:

[0088] Table 1 Comparison of test results

[0089]

[0090] As shown in Table 1 above, the vanadium-iron smelting method of the present invention results in low TV content in the slag, low aluminum content in the vanadium-iron alloy, stable aluminum content controlled below 0.50%, low aluminum consumption, and high vanadium yield.

[0091] Figure 2 The microstructure of the FeV80 alloy obtained according to the method of Comparative Example 1 is shown. Figure 3 A microstructure diagram of the FeV80 alloy obtained according to the method of Example 1 is shown. As shown in the figure, the ferrovanadium alloy prepared by the method of the present invention has no obvious alumina inclusions, while the ferrovanadium alloy prepared by conventional methods has alumina inclusions.

[0092] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0093] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0094] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A method for controlling the aluminum content in ferrovanadium alloys, characterized in that, Includes the following steps: Step S1: Calculate the effective oxygen content based on the total vanadium content, total potassium and sodium content, sulfur content, and oxygen content in volatile sulfur dioxide of the reaction raw materials. Effective oxygen refers to the portion of oxygen that participates in the redox reaction of aluminum and consumes aluminum during the aluminothermic reaction. The effective oxygen content Q is calculated as follows: Q = 1 - ABC Where A is the total vanadium content in vanadium oxide, B is the total potassium and sodium content in vanadium oxide, and C is the sum of the sulfur content in vanadium oxide and the oxygen content carried by the volatilization in the form of sulfur dioxide. Step S2: Calculate the corrected baseline aluminum content factor based on the effective oxygen content and baseline aluminum content formula obtained in Step S1; Step S3: Calculate the amount of raw materials according to the type of ferrovanadium alloy to be prepared and the requirements for preparing ferrovanadium alloy by electroaluminothermic reaction, wherein the amount of aluminum is determined according to the modified reference aluminum factor calculated in step S2. Step S4: Weigh vanadium oxide, aluminum, iron and lime according to the amount of ingredients calculated in step S3, mix the raw materials evenly to obtain a mixture; Step S5: Add the mixture to a smelting furnace and smelt it by electricity; Step S6: Refining is carried out after smelting is completed; Step S7: After refining, air cool. When the surface temperature of the corundum slag meets the requirements, dismantle the furnace, remove the alloy cake, and water quench it. Step S8: Crush and refine the alloy cake to obtain the vanadium-iron alloy.

2. The method according to claim 1, characterized in that, In step S1, the vanadium oxide is at least one of vanadium trioxide and vanadium pentoxide.

3. The method according to claim 1, characterized in that, In step S2, the calculation method for the corrected reference aluminum factor D is as follows: D = 1.125Q = 1.125(1-ABC).

4. The method according to claim 1, characterized in that, The vanadium-iron alloy is FeV50 or FeV80.

5. The method according to claim 1, characterized in that, In step S5, the mixture is added to the smelting furnace either all at once or in batches.

6. The method according to claim 1, characterized in that, In step S6, the depleted material consists of ball-milled iron particles and aluminum pellets.

7. The method according to claim 1, characterized in that, In step S4, 70% to 80% of the lime is mixed with other raw materials, and the remaining lime is added at the end of the refining process in step S6.

8. The method according to claim 7, characterized in that, In step S6, after the slag reduction is enhanced by energizing for 15-35 minutes, the remaining lime is added.

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