Method for directional removal of harmful elements in multi-source vanadium materials

Abstract

The present application relates to the technical field of vanadium metallurgy, and proposes a method for directional removal of harmful elements in multi-source vanadium materials, comprising: based on different smelting stages, adjusting the smelting temperature, the basicity range of the slag and the oxidation level in stages to build a slag-gold reaction environment corresponding to each stage; for at least one harmful element in the multi-source material, based on the difference in physical and chemical properties of the harmful element and vanadium in the slag-gold reaction environment, the harmful element is selectively oxidized and enters the slag or gas phase in the form of an oxide, realizing the directional removal of the harmful element. The scheme of the present application realizes a technical leap from "passive homogenization" to "active removal", through the construction of a specific slag-gold reaction environment, the simultaneous control of multiple harmful elements such as phosphorus, manganese, silicon and carbon in a smelting process is realized, the smelting process is simplified and the processing efficiency is improved, and the purpose of purifying the alloy from the source is realized.

Description

Technical Field

[0001] This invention relates to the field of vanadium metallurgy technology, and in particular to a method for the targeted removal of harmful elements from multi-source vanadium materials. Background Technology

[0002] In the field of vanadium metallurgy, multi-source vanadium materials usually contain a variety of harmful elements such as phosphorus, manganese, silicon, and carbon. The presence of these elements can significantly affect the product quality and application performance of vanadium alloys.

[0003] Existing technologies for processing such materials often employ traditional smelting methods to passively homogenize impurity elements. This involves simple melting or alloying to distribute impurities evenly within the alloy, but this approach fails to fundamentally remove them. Consequently, harmful elements remain in the final product, making it difficult to meet the purity requirements of high-end materials. Furthermore, due to the varying physicochemical properties of different harmful elements, existing processes struggle to achieve synergistic control of multiple impurities. Typically, step-by-step processing or the use of different slag systems for separate removal is required, resulting in complex processes, high energy consumption, and low efficiency.

[0004] Therefore, there is an urgent need for a universal method that can selectively and directionally remove multiple hazardous elements in order to purify alloys from the source and improve product quality. Summary of the Invention

[0005] To address the problem that existing technologies, when processing multi-source vanadium materials, can only passively homogenize harmful elements without actively removing them, and are difficult to achieve synergistic control of multiple harmful elements through a single process, resulting in impurities remaining in the final product and affecting the quality of vanadium alloys, this invention proposes a method for the targeted removal of harmful elements from multi-source vanadium materials, comprising: Step a: Based on different smelting stages, adjust the smelting temperature, slag alkalinity range, and oxidizing power in stages to construct a slag-gold reaction environment corresponding to each stage. Step b: For at least one hazardous element in the multi-source material, based on the difference in physicochemical properties between it and vanadium in the slag-gold reaction environment, it is selectively oxidized and enters the slag or gas phase in the form of oxide, thereby achieving the targeted removal of the hazardous element.

[0006] In some embodiments, the smelting stage includes: a lean slag period, a refining period, and a balancing period.

[0007] In some embodiments, step a includes: controlling the basicity of the slag during the lean slag period (CaO / SiO2) to be 0.60~0.70, the basicity of the slag during the refining period (CaO / SiO2) to be 0.50~0.60, and the basicity of the slag during the equilibrium period (CaO / SiO2) to be 0.40~0.50.

[0008] In some embodiments, step a includes adding lime to the smelting furnace in batches to adjust the alkalinity of the slag at each smelting stage to the corresponding range.

[0009] In some embodiments, step a further includes controlling the oxidizability of the slag to increase sequentially during the lean slag period, refining period, and equilibrium period.

[0010] In some embodiments, step a further includes: blowing oxygen into the smelting furnace during the equilibrium period so that the oxidizability of the slag is at its highest during the equilibrium period.

[0011] In some embodiments, step a further includes: controlling the smelting temperature of the lean slag period, refining period and equilibrium period to decrease sequentially.

[0012] In some embodiments, the hazardous elements include phosphorus, sulfur, carbon, manganese, and silicon.

[0013] In some embodiments, step b includes: selectively oxidizing any one of phosphorus, sulfur, manganese, and silicon, based on the difference in their physicochemical properties with vanadium in the slag-gold reaction environment, and then introducing them into the slag as oxides.

[0014] In some embodiments, step b includes: selectively oxidizing the carbon to allow it to enter the gas phase as an oxide, based on the difference in its physicochemical properties with vanadium in the slag-gold reaction environment.

[0015] This invention offers at least the following beneficial effects: It proposes a method for the targeted removal of hazardous elements from multi-source vanadium materials, achieving a technological leap from "passive homogenization" to "active removal." By constructing a specific slag-gold reaction environment, it achieves synergistic control of multiple hazardous elements such as phosphorus, manganese, silicon, and carbon within a single smelting process, simplifying the smelting process and improving processing efficiency, thus purifying the alloy from its source. Specifically, in step a, by adjusting the temperature, slag basicity, and oxidizing properties in stages based on different smelting stages, precise matching of the differentiated removal windows for hazardous elements with different physicochemical properties is achieved, resulting in the simultaneous and effective removal of different hazardous elements. In step b, by utilizing the differences in physical properties between hazardous elements and vanadium in a specific slag-gold reaction environment for selective oxidation, phosphorus, silicon, and manganese are stably introduced into the slag in oxide form, while carbon is introduced into the gas phase in oxide form, achieving the directional migration of hazardous elements from the alloy melt, avoiding impurities in the final product, and significantly improving the product quality and application performance of vanadium alloys. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other embodiments can be obtained based on these drawings without creative effort.

[0017] Figure 1 A flowchart of a method for targeted removal of hazardous elements from multi-source vanadium materials, provided as an embodiment of the present invention; Figure 2 A schematic diagram of a slag system for multi-source vanadium materials provided in an embodiment of the present invention; Figure 3 This is a schematic diagram illustrating the impurity control principle of multi-source vanadium materials according to an embodiment of the present invention. Detailed Implementation

[0018] The following describes embodiments of the present invention. However, it should be understood that the disclosed embodiments are merely examples, and other embodiments may take various alternative forms.

[0019] Furthermore, it should be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or apparatus that comprises a list of elements may include not only those elements but also elements not expressly listed or inherent to such process, method, article, or apparatus.

[0020] One or more embodiments of the present invention will now be described with reference to the accompanying drawings.

[0021] Based on the above objectives, this invention provides an embodiment of a method for the targeted removal of hazardous elements from multi-source vanadium materials, referring to... Figures 1-3 A method for the targeted removal of hazardous elements from multi-source vanadium materials, comprising: Step a: Based on different smelting stages, adjust the smelting temperature, slag alkalinity range, and oxidizing properties in stages to construct a slag-gold reaction environment corresponding to each stage.

[0022] It is important to understand that basicity refers to the mass ratio of basic oxides to acidic oxides in slag. In this invention, it specifically refers to the mass ratio of calcium oxide (CaO) to silicon dioxide (SiO2), i.e., CaO / SiO2, which is a key indicator for measuring the acidity, alkalinity, and reactivity of slag. Oxidizing power refers to the ability of slag to provide oxygen to the molten metal, and is usually related to the activity of easily decomposable oxides such as iron oxide (FeO) in the slag. Oxidizing power determines whether elements are oxidized into the slag phase or gas phase, or reduced into the metal phase. The slag-metal reaction environment is a comprehensive process condition, jointly constituted by the basicity, oxidizing power, and smelting temperature of the slag. These three core parameters are coupled and determine the distribution behavior and reaction direction of harmful elements such as phosphorus, sulfur, carbon, manganese, and silicon with the target element vanadium between the slag and metal phases.

[0023] As a feasible implementation, the different smelting stages can be specifically divided into three consecutive process periods: the lean slag period, the refining period, and the equilibrium period. This division of three stages is based on precise control of the entire reaction process, aiming to respectively accomplish the tasks of vanadium reduction, impurity suppression, and deep purification, thereby achieving the synergistic removal of multiple harmful elements.

[0024] Step a above, by adjusting the temperature, slag alkalinity and oxidizing properties in stages based on different smelting stages, achieves precise matching of the differentiated removal windows for hazardous elements with different physicochemical properties, and achieves simultaneous and effective removal of different hazardous elements.

[0025] Step b: For at least one hazardous element in the multi-source material, based on the difference in physicochemical properties between it and vanadium in the slag-gold reaction environment, it is selectively oxidized and enters the slag or gas phase in the form of oxide, thereby achieving the targeted removal of hazardous elements.

[0026] For example, targeting at least one hazardous element (such as phosphorus, sulfur, carbon, manganese, silicon, etc.) present in multi-source materials, the differences in physicochemical properties between these elements and vanadium in the specific slag-gold reaction environment constructed in step a are utilized. Different elements exhibit varying degrees of oxidization or reduction under the same alkalinity and oxygen potential, or their oxidation products exhibit different thermal stability, allowing for the selective oxidation of these hazardous elements. After oxidation, they migrate in the form of oxides. Oxides of phosphorus, silicon, manganese, etc. (such as P2O5, SiO2, MnO) combine with CaO in the slag and stably enter the slag; oxides of carbon (CO or CO2) enter the gas phase in the form of bubbles. Through this method, the targeted removal of the hazardous element is ultimately achieved.

[0027] Step b above utilizes the difference in physical properties between harmful elements and vanadium in a specific slag-gold reaction environment for selective oxidation. This enables phosphorus, silicon, manganese, etc., to stably enter the slag in oxide form, and carbon to migrate into the gas phase in oxide form. Ultimately, this achieves the complete removal of harmful elements from the alloy melt, avoids the residue of impurities in the final product, and significantly improves the product quality and application performance of vanadium alloys.

[0028] The aforementioned method for targeted removal of hazardous elements from multi-source vanadium materials represents a technological leap from "passive homogenization" to "active removal." By constructing a specific slag-gold reaction environment, it achieves synergistic control of multiple hazardous elements such as phosphorus, manganese, silicon, and carbon within a single smelting process. This simplifies the smelting process, improves processing efficiency, and ultimately purifies the alloy from its source.

[0029] According to several embodiments of the present invention, the smelting stage includes: a lean slag period, a refining period, and an equilibrium period. Step a includes: controlling the slag basicity (CaO / SiO2) of the slag during the lean slag period to be 0.60~0.70. The high basicity at this stage helps stabilize the slag composition and prepares for subsequent reactions; the slag basicity (CaO / SiO2) of the slag during the refining period is 0.50~0.60, and the slag basicity (CaO / SiO2) of the slag during the equilibrium period is 0.40~0.50. This dynamically decreasing basicity path is to match the different thermodynamic requirements of each stage.

[0030] According to several embodiments of the present invention, step a includes: adding lime to the smelting furnace in batches to adjust the basicity of the slag at each smelting stage to the corresponding range. For example, a batch of lime is added in the early stage of smelting (lean slag stage) to achieve an basicity of 0.60~0.70; in the middle stage of smelting (refining stage), lime is added again according to the furnace condition and analysis results to adjust the basicity to 0.50~0.60; in the later stage of smelting (equilibrium stage), lime addition is stopped or a small adjustment is made according to the final equilibrium requirements to stabilize the basicity at 0.40~0.50. This batch-addition method can avoid drastic fluctuations in slag composition caused by adding too much at once, and achieve precise and stable control of slag basicity.

[0031] In some embodiments, to achieve selective removal of different elements, in addition to basicity, the oxidizability of the slag is controlled in stages, and the control trend differs from that of basicity. Specifically, step a further includes controlling the oxidizability of the slag to increase sequentially during the lean slag period, refining period, and equilibrium period. The lean slag period requires low oxidizability (reducing atmosphere) to protect vanadium from excessive oxidation and ensure its reduction into the alloy; while in the equilibrium period, high oxidizability is required to oxidize and remove harmful elements such as carbon and phosphorus remaining in the alloy.

[0032] According to several embodiments of the present invention, step a further includes: blowing oxygen into the smelting furnace during the equilibrium period to maximize the oxidizability of the slag during the equilibrium period. As a feasible embodiment, the specific operation to achieve the highest oxidizability during the equilibrium period is to blow oxygen into the smelting furnace. For example, during the equilibrium period, industrial pure oxygen or oxygen-enriched air is blown into the molten pool through an oxygen lance, significantly increasing the oxygen potential (i.e., oxidizability) of the slag, thereby oxidizing the residual carbon in the alloy into CO gas, which escapes, and oxidizing phosphorus, silicon, etc., which then enter the slag, achieving the final refining effect.

[0033] In some embodiments, the phased adjustment also involves temperature control, which follows a trend similar to basicity but opposite to oxidizing properties. As a specific embodiment, step a further includes controlling the smelting temperature to decrease sequentially during the lean slag period, refining period, and equilibrium period. For example, the lean slag period can be controlled at a higher temperature range (e.g., 1500~1600℃, or above 2000℃ if vanadium-containing materials are added) to facilitate the kinetic conditions of the reduction reaction; the refining period temperature is moderate (e.g., 1450~1550℃) to balance the needs of impurity removal and heat preservation; the equilibrium period uses a relatively lower temperature (e.g., 1400~1500℃), which is conducive to the stable existence of oxidation products (e.g., oxides of phosphorus and silicon) in the slag, preventing them from being reduced back into the alloy, thereby achieving deep removal of harmful elements and final dynamic equilibrium. Maintaining an average temperature of 1900℃ across the three stages, until the molten pool reaches a liquid state, is sufficient.

[0034] According to several embodiments of the present invention, hazardous elements include, but are not limited to, phosphorus, sulfur, carbon, manganese, and silicon. These elements are generally considered impurities in the final vanadium product and need to be removed to improve product quality.

[0035] According to several embodiments of the present invention, step b includes: selectively oxidizing any one of phosphorus, sulfur, manganese, and silicon, based on the difference in their physicochemical properties with vanadium in the slag-gold reaction environment, and then introducing them into the slag in the form of oxides.

[0036] In some embodiments, the specific reaction process of step b is as follows: For any one of the hazardous elements—phosphorus, sulfur, manganese, and silicon—in a slag-gold reaction environment with corresponding alkalinity and high oxidizing power constructed during the refining or equilibration period, these elements are preferentially oxidized based on their differences in physicochemical properties with vanadium. For example, phosphorus is oxidized to P₂O₅, which immediately combines with CaO in the slag to form stable calcium phosphate (e.g., 3CaO•P₂O₅) and enters the slag; silicon is oxidized to SiO₂, which combines with CaO to form calcium silicate and enters the slag; manganese is oxidized to MnO, which, as an alkaline oxide, also enters the slag. Sulfur enters the slag phase by forming CaS. In this way, the targeted removal of these elements from the slag is achieved.

[0037] According to several embodiments of the present invention, step b includes: selectively oxidizing carbon, based on the difference in its physicochemical properties with vanadium in the slag-gold reaction environment, and then allowing it to enter the gas phase in the form of an oxide.

[0038] In other embodiments, the removal pathway for the hazardous element carbon (C) differs from that for phosphorus, silicon, and others. Under the highly oxidizing environment of the equilibrium period, particularly during oxygen blowing operations, carbon is selectively oxidized to CO or CO2 gas due to its physicochemical differences from vanadium. These gaseous oxides rise from the molten pool as bubbles and are eventually removed into the furnace gas (gas phase).

[0039] For a further understanding of the present invention, please refer to Figures 1-3 The specific embodiments of the present invention will be described in detail below.

[0040] As a specific embodiment, the present invention provides a method for the targeted removal of harmful elements from multi-source vanadium materials, the principle of which includes slag system design and impurity control as follows: Figures 2-3 As shown, by controlling the slag basicity and oxidizing properties in stages during the smelting process, and combining this with temperature regulation, a specific slag structure can be constructed. This method utilizes a gold-reacting environment to achieve the synergistic and targeted removal of multiple harmful elements such as phosphorus, sulfur, carbon, manganese, and silicon. The smelting process is divided into three consecutive phases: lean slag phase, refining phase, and equilibrium phase. Based on an acidic slag system, the slag alkalinity (CaO / SiO2) is dynamically adjusted by adding lime in batches to meet the reaction requirements of each stage.

[0041] Specifically, during the lean slag stage, reduction smelting is carried out under high temperature, high basicity, and low oxidizing conditions. The slag basicity is controlled at 0.60~0.70, and the smelting temperature is maintained at a relatively high level (e.g., 1550~1600℃), while maintaining a low oxidizing atmosphere. The main purpose of this stage is to reduce vanadium oxide to elemental vanadium to the greatest extent possible, allowing it to enter the alloy phase, while inhibiting the reduction of other harmful elements, thus creating conditions for subsequent removal.

[0042] During the refining stage, the smelting temperature is adjusted to a medium temperature range (e.g., 1500~1550℃), the slag basicity is controlled at 0.50~0.60, and the slag oxidizing property is increased to medium oxidizing property. The purpose of this stage is to minimize the reduction of harmful elements such as phosphorus, sulfur, silicon, and manganese into the alloy, while promoting their selective oxidation so that they enter the slag as oxides. For example, phosphorus is oxidized to P2O5 and combines with CaO in the slag to form stable calcium phosphate, which enters the slag; silicon is oxidized to SiO2 and combines with CaO to form calcium silicate, which enters the slag; and manganese is oxidized to MnO and enters the slag as a basic oxide.

[0043] During the equilibrium period, the smelting temperature is reduced to a low-temperature range (e.g., 1450~1500℃), the slag basicity is controlled at 0.40~0.50, and oxygen blowing is used to achieve high oxidizability in the slag. The purpose of this stage is to further remove harmful elements remaining in the alloy and achieve a dynamic balance between harmful elements in the vanadium alloy and the smelting slag. Under high oxidizability conditions, carbon is selectively oxidized to generate CO or CO2 gas, which rises from the molten pool into the gas phase as bubbles; any trace amounts of phosphorus, silicon, etc., that may remain are further oxidized and enter the slag. The low-temperature control during the equilibrium period is beneficial to the stable existence of oxidation products in the slag, preventing them from being reduced back into the alloy.

[0044] The design and control range of the slag system for the targeted removal of key hazardous elements in the above-mentioned multi-source vanadium materials are shown in Table 1 below.

[0045] Table 1

[0046] The basicity adjustment in each of the above stages is achieved by adding lime to the smelting furnace in batches. For example, a batch of lime is added during the lean slag stage to bring the basicity to 0.60~0.70. During the refining stage, lime is added again according to the furnace conditions to adjust the basicity to 0.50~0.60. During the equilibrium stage, lime addition is stopped or fine-tuned to stabilize the basicity at 0.40~0.50. The high oxidizing power during the equilibrium stage is achieved by blowing industrial pure oxygen or oxygen-enriched air into the molten pool.

[0047] For example, when processing a specific multi-source vanadium-containing material, the process is operated according to the above process parameters: First, in the lean slag stage, the temperature is controlled at 1580℃ and the basicity is 0.68 to maintain low oxidizing power, so that vanadium is fully reduced and enters the alloy; then, in the refining stage, the temperature is adjusted to 1520℃ and the basicity is 0.55 to increase the oxidizing power to medium, so that impurities such as phosphorus, silicon, and manganese are oxidized and enter the slag; finally, in the equilibrium stage, the temperature is lowered to 1480℃ and the basicity is 0.45. High oxidizing power is achieved through oxygen blowing, so that carbon is oxidized into CO gas and enters the gas phase.

[0048] The entire process described above achieves the synergistic and targeted removal of multiple harmful elements such as phosphorus, sulfur, carbon, manganese, and silicon, ultimately yielding high-purity vanadium alloy products, which significantly improves product quality and application performance.

[0049] The above are exemplary embodiments disclosed in this invention. However, it should be noted that various changes and modifications can be made without departing from the scope of the embodiments of this invention as defined by the claims. The functions, steps, and / or actions of the methods according to the disclosed embodiments described herein do not need to be performed in any particular order. Furthermore, although the elements disclosed in the embodiments of this invention may be described or claimed individually, they may be understood as multiple unless explicitly limited to a singular number.

[0050] It should be understood that, as used herein, the singular form “a” is intended to include the plural form as well, unless the context clearly supports an exception. It should also be understood that, as used herein, “and / or” refers to any and all possible combinations of one or more of the associated listed items.

[0051] The embodiment numbers disclosed in the above embodiments of the present invention are merely for description and do not represent the superiority or inferiority of the embodiments.

[0052] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention (including the claims) is limited to these examples. Within the framework of the invention, technical features of the above embodiments or different embodiments can be combined, and many other variations of different aspects of the invention exist, which are not provided in the details for the sake of brevity. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the invention should be included within the protection scope of the invention.

Claims

1. A method for the targeted removal of harmful elements from multi-source vanadium materials, characterized in that, include: Step a: Based on different smelting stages, adjust the smelting temperature, slag alkalinity range, and oxidizing power in stages to construct a slag-gold reaction environment corresponding to each stage. Step b: For at least one hazardous element in the multi-source material, based on the difference in physicochemical properties between it and vanadium in the slag-gold reaction environment, it is selectively oxidized and enters the slag or gas phase in the form of oxide, thereby achieving the targeted removal of the hazardous element.

2. The method for targeted removal of hazardous elements from multi-source vanadium materials according to claim 1, characterized in that, The smelting stages include: lean slag period, refining period, and equilibrium period.

3. The method for targeted removal of hazardous elements from multi-source vanadium materials according to claim 2, characterized in that, Step a includes: The basicity of the slag during the lean slag period (CaO / SiO2) is controlled to be 0.60~0.70, the basicity of the slag during the refining period (CaO / SiO2) is controlled to be 0.50~0.60, and the basicity of the slag during the equilibrium period (CaO / SiO2) is controlled to be 0.40~0.

50.

4. The method for targeted removal of hazardous elements from multi-source vanadium materials according to claim 3, characterized in that, Step a includes: Lime is added to the smelting furnace in batches to adjust the alkalinity of the slag at each smelting stage to the corresponding range.

5. The method for targeted removal of hazardous elements from multi-source vanadium materials according to claim 3, characterized in that, Step a further includes: The oxidizing power of the slag increases sequentially during the lean slag period, refining period, and equilibrium period.

6. The method for targeted removal of hazardous elements from multi-source vanadium materials according to claim 5, characterized in that, Step a further includes: During the equilibrium period, oxygen is blown into the smelting furnace to maximize the oxidizability of the slag during the equilibrium period.

7. The method for targeted removal of hazardous elements from multi-source vanadium materials according to claim 5, characterized in that, Step a further includes: The smelting temperature during the lean slag period, refining period, and equilibrium period is controlled to decrease sequentially.

8. The method for targeted removal of hazardous elements from multi-source vanadium materials according to claim 1, characterized in that, The hazardous elements include: phosphorus, sulfur, carbon, manganese, and silicon.

9. The method for targeted removal of hazardous elements from multi-source vanadium materials according to claim 8, characterized in that, Step b includes: For any one of the phosphorus, sulfur, manganese, and silicon, based on the difference in their physicochemical properties with vanadium in the slag-gold reaction environment, they are selectively oxidized and enter the slag in the form of oxides.

10. The method for targeted removal of hazardous elements from multi-source vanadium materials according to claim 8, characterized in that, Step b includes: Regarding the carbon, based on the difference in its physicochemical properties with vanadium in the slag-gold reaction environment, it is selectively oxidized and enters the gas phase in the form of oxides.

Images