A method for preparing a vanadium-aluminum alloy with a controllable vanadium-aluminum molar ratio

Abstract

The present invention provides a method for preparing a vanadium-aluminum alloy with a controllable vanadium-aluminum molar ratio, the preparation method comprising the following steps: (1) mixing vanadium oxide with CaO, a reducing agent and a reducing auxiliary agent, and reducing the mixture to obtain a reduced raw material; the reducing agent comprises aluminum; (2) reducing the reduced raw material and then wet-processing the reduced raw material to obtain VAl x The present invention uses aluminum reduction to form a wet-processable aluminum-containing phase under the action of calcium oxide and a reducing auxiliary agent, thereby obtaining a vanadium-aluminum alloy with precisely controlled aluminum content. The process is simple, the product is highly controllable, and the application prospects are broad.

Description

Technical Field

[0001] The present invention relates to the technical field of vanadium-aluminum alloy preparation, and in particular to a method for preparing a vanadium-aluminum alloy with a controllable vanadium-aluminum molar ratio. Background Art

[0002] Vanadium-aluminum alloy is a high-grade alloy material characterized by high hardness, high elasticity, strong seawater corrosion resistance, and lightweight. It can be used to manufacture seaplanes and water gliders. Furthermore, vanadium-aluminum alloy is an important raw material for the production of titanium alloys. It can improve the alloy's heat resistance and cold working properties, imparting excellent weldability and mechanical strength.

[0003] Currently, the production process for vanadium-aluminum alloys primarily uses vanadium pentoxide as the raw material and aluminum powder as the reducing agent, synthesized via self-propagating high-temperature synthesis (SHS). This process primarily involves mixing the raw materials, igniting the reaction, cooling the mixture, separating the slag from the metal, treating the metal, and crushing it. However, these separation steps are lengthy, require high operating temperatures, and consume significant energy. Furthermore, the aluminum content of vanadium-aluminum alloys produced by existing reduction processes is limited to 40% by weight. Because the difficulty of separating the slag from the metal increases with aluminum content, vanadium-aluminum alloys with higher aluminum contents are difficult to produce directly using aluminothermic reduction.

[0004] CN102127658A discloses a method for preparing a high-purity aluminum-vanadium master alloy. This method uses nitrogen or argon as a carrier and evenly sprays a refining agent into the aluminum melt for refining and slag removal. However, this process has requirements for the flow rate of nitrogen or argon, the amount of refining agent, the temperature, etc., and a 1mm to 3mm thick potassium salt or sodium salt covering agent for the aluminum melt is sprinkled on the surface of the molten aluminum, resulting in a complicated process flow.

[0005] CN113652567A discloses a vanadium-aluminum alloy and a preparation method thereof. In this method, vanadium pentoxide powder, aluminum powder, and a slagging agent are mixed and dried, or premixed and then mixed and dried to obtain a mixture. An oxidant is then added to the surface of the mixture, ignited, and the mixture undergoes a combustion reaction. After the reaction, the mixture is post-processed to obtain an alloy ingot, which is then crushed to obtain the vanadium-aluminum alloy. This method requires the preparation of an alloy ingot, which makes it difficult to ensure powder quality. Furthermore, the method requires a combustion reaction, resulting in low operational safety and a lengthy process.

[0006] CN103849787A discloses a method for preparing an aerospace-grade vanadium-aluminum alloy. The method comprises the following steps: mixing vanadium pentoxide, metallic aluminum, and a coolant, then charging the mixture into a smelting furnace, igniting and smelting the mixture to obtain a vanadium-aluminum alloy containing 75-85 wt% vanadium and slag; and remelting the vanadium-aluminum alloy in a vacuum induction furnace with aluminum, followed by refining to obtain an aerospace-grade vanadium-aluminum alloy containing 45-55 wt% vanadium. This method requires aluminum remelting of the vanadium-aluminum alloy, resulting in high operating costs and demanding equipment.

[0007] Therefore, the existing method for preparing vanadium-aluminum alloy uses aluminum to reduce vanadium pentoxide, and the subsequent processes all require high-temperature treatment, which has high operating costs and complex process flows. It is necessary to develop a vanadium-aluminum alloy preparation process with lower costs and safer operations. Summary of the Invention

[0008] In view of the problems existing in the prior art, the present invention provides a method for preparing a vanadium-aluminum alloy with a controllable vanadium-aluminum molar ratio. The preparation method can optimize the phase state of aluminum reduction by-products by adding calcium oxide and a reduction auxiliary agent during the process of aluminum reducing vanadium oxide, so that the by-products can be wet-processed and separated from vanadium and aluminum, thereby greatly shortening the process of preparing the vanadium-aluminum alloy. The vanadium-aluminum alloy can be prepared without the need for operations such as slag-metal separation, and the vanadium-aluminum molar ratio in the vanadium-aluminum alloy product can be precisely controlled, and the application prospect is broad.

[0009] To achieve this object, the present invention adopts the following technical solutions:

[0010] The present invention provides a method for preparing a vanadium-aluminum alloy with a controllable vanadium-aluminum molar ratio, the preparation method comprising the following steps:

[0011] (1) mixing vanadium oxide with CaO, a reducing agent and a reduction auxiliary agent, and reducing the mixture to obtain a raw material; the reducing agent includes aluminum;

[0012] (2) The reduced material is subjected to wet treatment after reduction to obtain VAl x Alloy, wherein the value range of x is 0.20≤x≤5.80, for example, it can be 0.20, 0.25, 0.30, 0.40, 0.50, 0.80, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0 or 5.8, etc., but is not limited to the listed values, and other values ​​not listed in the range are also applicable.

[0013] The preparation method of the vanadium-aluminum alloy provided by the present invention comprises adding calcium oxide and a reduction auxiliary agent to the aluminum reduction of vanadium oxide, thereby converting the aluminum-oxygen phase that cannot be wet-separated after reduction into a phase that can be wet-separated, thereby enabling the aluminum oxide-enriched by-product phase and the vanadium-aluminum alloy to be separated by wet treatment after reduction in step (2) to obtain the vanadium-aluminum alloy.

[0014] Moreover, due to the short process of the present invention, which only requires one reduction step, the vanadium-aluminum molar ratio of the vanadium-aluminum alloy in the product can be accurately controlled by the amount of raw materials added, thereby providing a basis for the preparation of vanadium-aluminum alloys required in different occasions and greatly expanding the application scope of the preparation method.

[0015] Preferably, the vanadium oxide in step (1) includes V2O3 and / or V2O5.

[0016] Preferably, the reduction temperature in step (1) is 700-1400°C, for example, 700°C, 778°C, 856°C, 934°C, 1012°C, 1089°C, 1167°C, 1245°C, 1323°C or 1400°C, but is not limited to the listed values, and other values ​​not listed within the range are also applicable.

[0017] The present invention further preferably controls the reduction temperature within the above range, which is more conducive to controlling the reduction effect and ensuring that no alumina-enriched by-product phase that is poorly soluble in water and / or acid is produced.

[0018] Preferably, the reduction time is 0.25 to 24 h, for example, 0.25 h, 2.89 h, 5.53 h, 8.17 h, 10.81 h, 13.45 h, 16.09 h, 18.73 h, 21.37 h or 24 h, but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0019] Preferably, the reducing atmosphere is a vacuum or protective atmosphere.

[0020] Preferably, the reducing protective atmosphere comprises any one of argon, hydrogen or helium, or a combination of at least two of them, wherein typical but non-limiting combinations are a combination of argon and hydrogen, a combination of helium and hydrogen, and a combination of argon and helium.

[0021] Preferably, the molar ratio of the reducing agent to the vanadium oxide in step (1) is (2ax+2bx+10b / 3+2a):(a+b), wherein x is VAl x The value of x in the alloy, a / (a+b) is the molar ratio of vanadium trioxide in the vanadium oxide, and b / (a+b) is the molar ratio of vanadium pentoxide in the vanadium oxide.

[0022] The present invention has only one reduction step, through the chemical equation:

[0023] aV2O3+bV2O5+(2ax+2bx+10b / 3+2a)Al=(2a+2b)VAl x +(5b / 3+a)Al2O3, when vanadium aluminum alloy VAl is needed xWhen the value of x in the product is specifically limited, the corresponding product can be obtained directly by controlling the amount of reducing agent added. Although the present invention uses the above equation to calculate the value of x, the reduction byproduct is not aluminum oxide, but a phase containing aluminum and calcium that is soluble in dilute acid.

[0024] Preferably, the molar ratio of CaO to the reducing agent in step (1) is 0.6 to 2:1, for example, it can be 0.6:1, 0.8:1, 1:1, 1.1:1, 1.3:1, 1.4:1, 1.6:1, 1.7:1, 1.9:1 or 2:1, but is not limited to the listed values, and other values ​​not listed within this range are also applicable.

[0025] The present invention further preferably controls the molar ratio of calcium oxide to reducing agent within the above range, which is more conducive to forming reduction by-products that can be wet-processed and avoids carrying a high oxygen content or impurities in the vanadium-aluminum alloy.

[0026] Preferably, the reduction auxiliary agent in step (1) comprises any one or a combination of at least two of anhydrous CaCl2, CaCl2-KCl eutectic salt, CaCl2-NaCl eutectic salt or CaCl2-LiCl eutectic salt, wherein a typical but non-limiting combination is a combination of anhydrous CaCl2 and a CaCl2-KCl eutectic salt, a combination of a CaCl2-NaCl eutectic salt and a CaCl2-KCl eutectic salt, and a combination of anhydrous CaCl2 and a CaCl2-LiCl eutectic salt.

[0027] Preferably, the weight ratio of the reduction auxiliary agent to the vanadium oxide is 0.05 to 3:1, for example, it can be 0.05:1, 0.35:1, 0.75:1, 1.05:1, 1.35:1, 1.65:1, 2.00:1, 2.35:1, 2.60:1 or 3:1, but is not limited to the listed values. Other values ​​not listed within this range are also applicable.

[0028] Preferably, the post-reduction wet treatment in step (2) comprises: slurrying the reduced material with water and / or acid solution to obtain a slurry; adjusting the pH of the slurry and performing solid-liquid separation in sequence, washing and drying the obtained solid phase to obtain VAl x alloy.

[0029] Preferably, the pH of the acid solution in the post-reduction wet treatment is ≥ 0.5, for example, it can be 0.5, 0.8, 1, 1.2, 1.4, 1.7, 1.9, 2.1, 2.3 or 2.5, etc., but is not limited to the listed values, and other values ​​not listed within this range are also applicable.

[0030] Preferably, the liquid-to-solid ratio of the slurry in the post-reduction wet treatment is 1 to 100:1 mL / g, for example, it can be 1:1 mL / g, 12:1 mL / g, 23:1 mL / g, 34:1 mL / g, 45:1 mL / g, 56:1 mL / g, 67:1 mL / g, 78:1 mL / g, 89:1 mL / g or 100:1 mL / g, but is not limited to the listed values, and other values ​​not listed within this range are also applicable.

[0031] Preferably, the acid used for pH adjustment in the post-reduction wet treatment includes hydrochloric acid.

[0032] Preferably, the pH of the slurry is controlled to be ≥0.8 during the pH adjustment process in the post-reduction wet treatment, for example, it can be 0.8, 1, 1.2, 1.4, 1.6, 1.8, 2, 2.2, 2.4 or 2.5, etc., but is not limited to the listed values, and other values ​​not listed within this range are also applicable.

[0033] Preferably, the pH of the slurry after pH adjustment in the post-reduction wet treatment is 1.5 to 3.0, for example, it can be 1.5, 1.7, 1.9, 2, 2.2, 2.4, 2.5, 2.7, 2.9 or 3.0, but is not limited to the listed values, and other values ​​not listed within this range are also applicable.

[0034] In the present invention, in order to prevent the vanadium aluminum alloy from dissolving with acid during the pH adjustment process, the slurry in the pH adjustment process is preferably controlled at a pH value above 0.8. The pH adjustment is considered to be completed when the pH value stabilizes between 1.5 and 3.0 and no longer changes.

[0035] Preferably, the washing temperature in the wet treatment after reduction is 0 to 60°C, for example, it can be 0°C, 7°C, 14°C, 20°C, 27°C, 34°C, 40°C, 47°C, 54°C or 60°C, etc., but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0036] Preferably, the drying temperature in the post-reduction wet treatment is ≤60°C, for example, 40°C, 43°C, 45°C, 47°C, 49°C, 52°C, 54°C, 56°C, 58°C, or 60°C, but is not limited to the listed values, and other values ​​not listed within this range are also applicable. The drying method is one of normal pressure or vacuum drying at no more than 60°C, or freeze drying. Controlling the drying temperature in the present invention can effectively prevent excessive oxidation of the vanadium aluminum alloy surface, and is more conducive to controlling the oxygen content level of the vanadium aluminum alloy.

[0037] Preferably, the preparation method further comprises: (3) the VAl xThe alloy is deoxidized by a deoxidizer, wherein the deoxidizer includes calcium, to obtain a deoxidized material. (4) The deoxidized material is subjected to a post-deoxidation wet treatment to obtain VAl with a low oxygen content. x alloy;

[0038] Preferably, the VAl with low oxygen content x The oxygen content in the alloy is ≤0.20wt%, for example, it can be 0.20wt%, 0.15wt%, 0.14wt%, 0.13wt%, 0.12wt%, 0.10wt%, 0.09wt% or 0.08wt%.

[0039] Preferably, the mass ratio of the VAlx alloy to the deoxidizer is 1:0.05 to 0.5, for example, 1:0.05, 1:0.1, 1:0.15, 1:0.2, 1:0.25, 1:0.3, 1:0.35, 1:0.4, 1:0.45 or 1:0.5, etc., but is not limited to the listed values, and other values ​​not listed within the range are also applicable.

[0040] Preferably, a deoxidation auxiliary agent is added during the deoxidation treatment.

[0041] Preferably, the deoxidation auxiliary agent includes any one or a combination of at least two of anhydrous CaCl2, CaCl2-MgCl2 eutectic salt, CaCl2-NaCl eutectic salt, CaCl2-KCl eutectic salt or CaCl2-LiCl eutectic salt, wherein typical but non-limiting combinations are a combination of anhydrous CaCl2 and a CaCl2-MgCl2 eutectic salt, a combination of a CaCl2-NaCl eutectic salt and a CaCl2-MgCl2 eutectic salt, and a combination of anhydrous CaCl2 and a CaCl2-KCl eutectic salt.

[0042] Preferably, the deoxidation auxiliary agent is x The weight ratio of the alloy is 0.05 to 3:1, for example, it can be 0.05:1, 0.38:1, 0.71:1, 1.04:1, 1.37:1, 1.69:1, 2.02:1, 2.35:1, 2.68:1 or 3:1, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0043] Preferably, the temperature of the deoxidation treatment is 700-1100°C, for example, it can be 700°C, 745°C, 789°C, 834°C, 878°C, 923°C, 967°C, 1012°C, 1056°C or 1100°C, but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0044] Preferably, the deoxygenation treatment time is 0.25 to 48 hours, for example, it can be 0.25 hours, 5 hours, 10 hours, 16 hours, 21 hours, 26 hours, 32 hours, 37 hours, 42 hours or 48 hours, but is not limited to the listed values, and other values ​​not listed within this range are also applicable.

[0045] Preferably, the atmosphere of the deoxidation treatment is a vacuum atmosphere or a protective atmosphere.

[0046] Preferably, the protective atmosphere of the deoxidation treatment includes any one of argon, hydrogen or helium, or a combination of at least two of them, wherein typical but non-limiting combinations are a combination of argon and hydrogen, a combination of helium and hydrogen, and a combination of argon and helium.

[0047] Preferably, the post-deoxidation wet treatment in step (3) comprises: slurrying the deoxidized material with water and / or acid solution to obtain a slurry. The slurry is sequentially subjected to pH adjustment and solid-liquid separation, and the obtained solid phase is washed and dried to obtain VAl with low oxygen content. x alloy;

[0048] Preferably, the pH of the acid solution in the post-deoxidation wet treatment is ≥ 0.5, for example, it can be 0.5, 0.8, 1, 1.2, 1.4, 1.7, 1.9, 2.1, 2.3 or 2.5, etc., but is not limited to the listed values, and other values ​​not listed within this range are also applicable.

[0049] Preferably, the liquid-to-solid ratio of the slurry in the wet treatment after deoxidation is 1 to 100:1 mL / g, for example, it can be 1:1 mL / g, 15:1 mL / g, 25:1 mL / g, 35:1 mL / g, 45:1 mL / g, 55:1 mL / g, 65:1 mL / g, 75:1 mL / g, 85:1 mL / g or 100:1 mL / g, but is not limited to the listed values, and other values ​​not listed within this range are also applicable.

[0050] Preferably, the acid used for pH adjustment in the wet treatment after deoxidation includes hydrochloric acid.

[0051] Preferably, the pH of the slurry is controlled to be ≥0.8 during the pH adjustment process in the wet treatment after deoxidation, for example, it can be 0.8, 1, 1.2, 1.4, 1.6, 1.8, 2, 2.2, 2.4 or 2.5, etc., but is not limited to the listed values, and other values ​​not listed within this range are also applicable.

[0052] Preferably, the pH of the slurry after pH adjustment in the post-deoxidation wet treatment is 1.5 to 3.0, for example, it can be 1.5, 1.7, 1.9, 2, 2.2, 2.4, 2.5, 2.7, 2.9 or 3.0, but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0053] In the present invention, in order to prevent the vanadium aluminum alloy from dissolving with acid during the pH adjustment process, the slurry in the pH adjustment process is preferably controlled at a pH value above 0.8. The pH adjustment is considered to be completed when the pH value stabilizes between 1.5 and 3.0 and no longer changes.

[0054] Preferably, the washing temperature in the wet treatment after deoxidation is 0 to 60°C, for example, it can be 0°C, 7°C, 14°C, 20°C, 27°C, 34°C, 40°C, 47°C, 54°C or 60°C, but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0055] Preferably, the drying temperature in the post-deoxidation wet treatment is ≤ 60°C, for example, 40°C, 43°C, 45°C, 47°C, 49°C, 52°C, 54°C, 56°C, 58°C, or 60°C, but is not limited to the listed values, and other values ​​not listed in this range are also applicable. The drying method is one of atmospheric pressure or vacuum drying at no more than 60°C, or freeze drying. Controlling the drying temperature in the present invention can effectively prevent excessive oxidation of the vanadium aluminum alloy surface, and is more conducive to controlling the oxygen content level of the final vanadium aluminum alloy.

[0056] As a preferred technical solution of the present invention, the preparation method comprises the following steps:

[0057] (1) Mixing vanadium oxide with CaO, a reducing agent and a reduction auxiliary agent, wherein the molar ratio of the reducing agent to the vanadium oxide is (2ax+2bx+10b / 3+2a):(a+b), where x is VAl x The alloy comprises the following components: x, a / (a+b) represents the molar ratio of vanadium trioxide in the vanadium oxide, b / (a+b) represents the molar ratio of vanadium pentoxide in the vanadium oxide, a molar ratio of CaO to the reducing agent is 0.6 to 2:1, and a weight ratio of the reduction auxiliary agent to the vanadium oxide is 0.05 to 3:1. The alloy is reduced at 700 to 1400° C. for 0.25 to 24 hours under vacuum or protective atmosphere to obtain a raw material; the reducing agent comprises aluminum;

[0058] (2) The reducing material is slurried with water and / or hydrochloric acid solution with a pH value of ≥0.5 to obtain a slurry; the slurry is pH-adjusted, and the pH value of the slurry is controlled to be ≥0.8 during the pH adjustment process. The pH value of the slurry after pH adjustment is stabilized at 1.5 to 3.0, and the solid-liquid separation is performed, and the obtained solid phase is washed at 0 to 60°C and dried at ≤60°C to obtain VAl x alloy, where x is in the range of 0.20≤x≤5.80.

[0059] Optionally, the preparation method further comprises:

[0060] (3) the VA1x The alloy is deoxidized at 700-1100°C for 0.25-48h in a vacuum or protective atmosphere with a deoxidizer and a deoxidizer auxiliary agent, wherein the deoxidizer includes calcium, VAl x The mass ratio of alloy to deoxidizer is 1:0.05~0.5, and the mass ratio of deoxidizer to VAl x The weight ratio of the alloy is 0.05 to 3:1 to obtain a deoxidized material;

[0061] (4) The deoxidized material is slurried with water and / or hydrochloric acid solution with a pH of ≥0.5 to obtain a slurry; the slurry is pH-adjusted, and the pH of the slurry is controlled to be ≥0.8 during the pH adjustment process. The pH of the slurry after pH adjustment is stabilized at 1.5-3.0, and solid-liquid separation is performed. The obtained solid phase is washed at 0-60°C and dried at ≤60°C to obtain VAl with an oxygen content of ≤0.20wt%. x alloy.

[0062] The present invention has no particular limitation on the solid-liquid separation in the above process. Any device and method for solid-liquid separation known to those skilled in the art can be used, and can also be adjusted according to the actual process. For example, it can be filtration, centrifugation or sedimentation separation, or a combination of different methods.

[0063] Compared with the prior art, the present invention has at least the following beneficial effects:

[0064] (1) The preparation method of the vanadium-aluminum alloy with controllable vanadium-aluminum molar ratio provided by the present invention can accurately control the Al / V molar ratio within a wide range of 0.2 to 5.8, has a wide range of applications, and its standard deviation after 5 repetitions is only ≤0.0062, with high stability;

[0065] (2) The method for preparing a vanadium-aluminum alloy with a controllable vanadium-aluminum molar ratio provided by the present invention can control the reduction byproducts to a phase that can be processed by a wet process by adding calcium oxide and a reduction auxiliary agent during aluminum reduction, thereby obtaining a vanadium-aluminum alloy through a short one-step reduction and one-step wet process, avoiding high-temperature and complex separation procedures such as slag-metal separation, resulting in lower costs and higher alloy purity. Under optimal conditions, the alloy purity is above 99.5wt%;

[0066] (3) The preparation method of the vanadium-aluminum alloy with a controllable vanadium-aluminum molar ratio provided by the present invention can also perform deoxidation treatment on vanadium-aluminum alloy products with requirements on oxygen content to further reduce the oxygen content. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] Figure 1 It is a process flow chart of a method for preparing a vanadium-aluminum alloy with a controllable vanadium-aluminum molar ratio provided by a specific embodiment of the present invention. DETAILED DESCRIPTION

[0068] The technical solution of the present invention will be further described below with reference to the accompanying drawings and through specific implementation methods.

[0069] The present invention is further described in detail below. However, the following examples are merely simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention shall be subject to the claims.

[0070] As a specific embodiment of the present invention, a method for preparing a vanadium-aluminum alloy with a controllable vanadium-aluminum molar ratio is provided, such as Figure 1 As shown, the preparation method comprises the following steps:

[0071] (1) mixing vanadium oxide with CaO, a reducing agent Al and a reduction auxiliary agent, and reducing the mixture to obtain a raw material;

[0072] (2) The reduced material is subjected to wet treatment after reduction, wherein the wet treatment after reduction comprises slurrying the reduced material with water and / or acid solution to obtain slurry; the slurry is pH-adjusted and subjected to solid-liquid separation, and the obtained solid phase is washed and dried to obtain VAl x alloy, where x is in the range of 0.20≤x≤5.80.

[0073] Optionally, the preparation method further comprises (indicated by dotted lines):

[0074] (3) the VA1 x The alloy is deoxidized by using a deoxidizer and a deoxidizing auxiliary agent to obtain a deoxidized material;

[0075] (4) The deoxidized material is subjected to a wet treatment after deoxidation, wherein the wet treatment comprises slurrying the deoxidized material with water and / or acid solution to obtain a slurry; the slurry is pH-adjusted and subjected to solid-liquid separation, and the obtained solid phase is washed and dried to obtain VAl with low oxygen content. x alloy.

[0076] Example 1

[0077] This embodiment provides a method for preparing a vanadium-aluminum alloy with a controllable vanadium-aluminum molar ratio, the preparation method comprising the following steps:

[0078] (1) Mixing vanadium oxide with CaO powder, Al powder and CaCl2-NaCl eutectic salt, wherein the molar ratio of Al powder to vanadium oxide is (2ax+2bx+10b / 3+2a):(a+b), where x is VAl x The value of x in the alloy, a / (a+b) is the molar ratio of vanadium trioxide in the vanadium oxide, and b / (a+b) is the molar ratio of vanadium pentoxide in the vanadium oxide, is reduced at 1300°C for 10 hours under vacuum or protective atmosphere to obtain the raw material;

[0079] (2) The reducing material is slurried with hydrochloric acid solution with a pH of 1.5 to obtain a slurry; the slurry is pH-adjusted, and the pH of the slurry is controlled to be ≥ 0.8 during the pH adjustment process. The pH of the slurry after pH adjustment is stabilized at 2.2, and filtered. The obtained solid phase is washed with water at 45°C and vacuum-dried at 55°C to obtain VAl x alloy, where x is in the range of 0.20≤x≤5.80.

[0080] In this embodiment, the specific molar ratio b:a of V2O5 to V2O3 in the vanadium oxide, the added amounts of calcium oxide, aluminum powder and CaCl2-NaCl eutectic salt, and the corresponding final value of x are shown in Table 1.

[0081] Table 1

[0082]

[0083] From Table 1 we can see the following points:

[0084] (1) From the perspective of Examples 1-3, 1-6 and 1-7, it can be seen that when the amount of calcium oxide added in Example 1-6 is too low, the alumina phase-enriched product is difficult to be dissolved by dilute acid, and the phase of the pickling product includes VAl x alloy and acid-insoluble calcium aluminate, while in Examples 1-7, adding too much calcium oxide will lead to excessive consumption of calcium oxide. This shows that the present invention can improve product purity and reduce calcium oxide consumption by controlling the molar ratio of calcium oxide to aluminum within a specific range;

[0085] (2) From the combination of Examples 1-3, 1-8 and 1-9, it can be seen that when the reduction auxiliary agent is added too little in Examples 1-9, the acid-soluble aluminum calcium by-product phase is difficult to be fully generated, resulting in the phase of the pickling product including VAl x The alloy and acid-insoluble calcium aluminate have high salt consumption in Examples 1-8. The present invention controls the weight ratio of the reduction auxiliary agent to the vanadium oxide within a specific range, which is beneficial to improving the product purity and reducing the consumption of the reduction auxiliary agent.

[0086] Example 2

[0087] This embodiment provides a method for preparing a vanadium-aluminum alloy with a controllable vanadium-aluminum molar ratio, the preparation method comprising the following steps:

[0088] (1) Mixing vanadium oxide with CaO powder, Al powder and anhydrous CaCl2, wherein the molar ratio of Al powder to vanadium oxide is (2ax+2bx+10b / 3+2a):(a+b), where x is VAl xThe value of x in the alloy, a / (a+b) is the molar ratio of vanadium trioxide in the vanadium oxide, and b / (a+b) is the molar ratio of vanadium pentoxide in the vanadium oxide. The raw material is reduced at 1400°C for 0.25h under vacuum or protective atmosphere;

[0089] (2) The reducing material is slurried with hydrochloric acid solution with a pH of 0.5 to obtain a slurry; the slurry is pH-adjusted, and the pH of the slurry is controlled to be ≥1.0 during the pH adjustment process. The pH of the slurry after pH adjustment is stabilized at 3.0, and filtered. The obtained solid phase is washed with water at 0°C and vacuum-dried at 60°C to obtain VAl x alloy, where x is in the range of 0.20≤x≤5.80;

[0090] (3) the VA1 x The alloy was deoxidized at 1100℃ for 0.25h with calcium as deoxidizer and anhydrous CaCl2 under vacuum. x The mass ratio of alloy to deoxidizer is 1:0.05, anhydrous CaCl2 and VAl x The weight ratio of the alloy is 0.2:1 to obtain a deoxidized material;

[0091] (4) The deoxidized material is slurried with water to obtain a slurry; the slurry is pH-adjusted, and the pH of the slurry is controlled to be ≥0.8 during the pH adjustment process. The pH of the slurry after pH adjustment is stabilized at 2.0, and filtered. The obtained solid phase is washed at 20°C and dried at 45°C to obtain VAl with low oxygen content. x alloy.

[0092] The specific molar ratio b:a of V2O5 to V2O3 in the vanadium oxide in this embodiment, the added amounts of calcium oxide, aluminum powder and anhydrous CaCl2, and the corresponding final value of x are shown in Table 2.

[0093] Table 2

[0094]

[0095] Example 3

[0096] This embodiment provides a method for preparing a vanadium-aluminum alloy with a controllable vanadium-aluminum molar ratio, the preparation method comprising the following steps:

[0097] (1) Mixing vanadium oxide with CaO powder, Al powder and CaCl2-KCl eutectic salt, wherein the molar ratio of Al powder to vanadium oxide is (2ax+2bx+10b / 3+2a):(a+b), where x is VAl xThe value of x in the alloy, a / (a+b) is the molar ratio of vanadium trioxide in the vanadium oxide, and b / (a+b) is the molar ratio of vanadium pentoxide in the vanadium oxide, is reduced at 700°C for 24 hours under vacuum or protective atmosphere to obtain the raw material;

[0098] (2) The reducing material is slurried with hydrochloric acid solution with a pH of 1.0 to obtain a slurry; the slurry is pH-adjusted, and the pH of the slurry is controlled to be ≥ 0.8 during the pH adjustment process. The pH of the slurry after pH adjustment is stabilized at 1.5, and filtered. The obtained solid phase is washed with water at 60°C and vacuum-dried at 45°C to obtain VAl x alloy, where x is in the range of 0.20≤x≤5.80;

[0099] (3) the VA1 x The alloy was deoxidized at 700℃ for 48h in helium atmosphere with calcium as deoxidizer and CaCl2-NaCl eutectic salt. x The mass ratio of alloy to deoxidizer is 1:0.5, CaCl2-NaCl eutectic salt and VAl x The weight ratio of the alloy is 3:1 to obtain a deoxidized material;

[0100] (4) The deoxidized material is slurried with water to obtain a slurry; the slurry is pH-adjusted, and the pH of the slurry is controlled to be ≥0.8 during the pH adjustment process. The pH of the slurry after pH adjustment is stabilized at 3.0, and filtered. The obtained solid phase is washed at 10°C and dried at 40°C to obtain VAl with low oxygen content. x alloy.

[0101] The specific molar ratio b:a of V2O5 to V2O3 in the vanadium oxide in this embodiment, the added amounts of calcium oxide, aluminum powder and anhydrous CaCl2, and the corresponding final value of x are shown in Table 3.

[0102] Table 3

[0103]

[0104] Example 4

[0105] This embodiment provides a method for preparing a vanadium-aluminum alloy with a controllable vanadium-aluminum molar ratio. Except for deoxidation treatment and post-deoxidation wet treatment after step (2), the rest is the same as that of Example 1-1.

[0106] Specifically, it also includes:

[0107] (3) the VA1 x The alloy was deoxidized at 1000℃ for 20h with calcium as deoxidizer and CaCl2-KCl eutectic salt in helium atmosphere. xThe mass ratio of alloy to deoxidizer is 1:0.3, CaCl2-KCl eutectic salt and VAl x The weight ratio of the alloy is 0.4:1 to obtain a deoxidized material;

[0108] (4) The deoxidized material was slurried with hydrochloric acid solution with a pH of 0.8 to obtain a slurry; the slurry was pH-adjusted, and the pH of the slurry was controlled to be ≥ 0.8 during the pH adjustment process. The pH of the slurry after pH adjustment was stabilized at 2.5, and filtered. The obtained solid phase was washed at 15°C and vacuum-dried at 45°C to obtain VAl with an oxygen content as low as 0.07%. x alloy.

[0109] Example 5

[0110] This embodiment provides a method for preparing a vanadium-aluminum alloy with a controllable vanadium-aluminum molar ratio. The preparation method is the same as that of Example 1, except that the reducing auxiliary agent CaCl2-NaCl eutectic salt is replaced by MgCl2. The results are shown in Table 4.

[0111] Table 4

[0112]

[0113] Comparative Example 1

[0114] This comparative example provides a method for preparing a vanadium-aluminum alloy. The preparation method is the same as Example 1-1 except that the aluminum powder is replaced with magnesium powder in an equal molar ratio. This comparative example does not have an aluminum source, and therefore no vanadium-aluminum alloy is obtained after reduction.

[0115] Comparative Example 2

[0116] This comparative example provides a method for preparing a vanadium-aluminum alloy. Except for not adding calcium oxide, the other conditions of the preparation method are the same as those of Example 1-1. The aluminum oxide-enriched by-product phase in the obtained reduction product cannot be completely dissolved by the dilute acid, and a vanadium-aluminum alloy with higher purity cannot be obtained.

[0117] From Example 1-1 and Comparative Examples 1-2, it can be seen that by adding calcium oxide and a reduction auxiliary agent to aluminum reduction, Example 1-1 can accurately produce VAl with an x ​​value of 0.2, compared with Comparative Example 1 using magnesium reduction and Comparative Example 2 without adding calcium oxide. x alloy, while comparative example 1 cannot form vanadium aluminum alloy. Although comparative example 2 can obtain vanadium aluminum alloy, the alumina-enriched by-product phase in the reduction product is mainly corundum phase, which cannot be dissolved by dilute acid. After pickling, a mixed phase of vanadium aluminum alloy and alumina is obtained.

[0118] Taking Example 1-1, Example 1-4, Example 2-1, and Example 3-3 as examples, the stability of the product components in the method of the present invention was explored, that is, each example was repeated 5 times, and the ICP-OES chemical composition analysis method was adopted and the value of x in the final product was calculated. The results are shown in Table 5.

[0119] Table 5

[0120] First time x Second time x The third time x The fourth time Fifth time x average value Standard Deviation Example 1-1 0.200 0.202 0.199 0.199 0.201 0.200 0.0013 Examples 1-4 4.000 4.005 4.007 3.992 3.996 4.000 0.0062 Example 2-1 0.301 0.308 0.293 0.299 0.302 0.301 0.0054 Example 3-3 2.000 2.004 1.995 2.001 1.998 2.000 0.0034

[0121] It can be seen from Table 5 that the preparation method of vanadium aluminum alloy provided by the present invention can reliably and stably prepare VAl with the required x value. x The standard deviation of the alloy repeated 5 times is only ≤0.0062, with high stability.

[0122] While the present invention is described through the above-described embodiments to illustrate the detailed structural features of the present invention, the present invention is not limited to these detailed structural features, nor does it necessarily rely on these detailed structural features for implementation. Those skilled in the art should understand that any improvements to the present invention, equivalent replacements for selected components, additions of auxiliary components, and selection of specific embodiments, etc., fall within the scope of protection and disclosure of the present invention.

Claims

1. A method for preparing a vanadium-aluminum alloy with a controllable vanadium-aluminum molar ratio, characterized in that: The preparation method comprises the following steps: (1) Mixing vanadium oxide with CaO, a reducing agent and a reduction auxiliary agent, and reducing the mixture to obtain a raw material; the reducing agent includes aluminum; the molar ratio of the reducing agent to the vanadium oxide is (2ax+2bx+10b / 3+2a):(a+b), wherein x is VAl x The value of x in the alloy, a / (a+b) is the molar ratio of vanadium trioxide in the vanadium oxide, and b / (a+b) is the molar ratio of vanadium pentoxide in the vanadium oxide; the molar ratio of CaO to the reducing agent is 0.6 to 2:1; the reduction auxiliary agent includes any one or a combination of at least two of anhydrous CaCl2, CaCl2-KCl eutectic salt, CaCl2-NaCl eutectic salt, or CaCl2-LiCl eutectic salt; the weight ratio of the reduction auxiliary agent to the vanadium oxide is 0.05 to 3:1; (2) The reduced material is subjected to wet treatment after reduction to obtain VAl x alloy, where x is in the range of 0.20≤x≤5.

80.

2. The preparation method according to claim 1, characterized in that The vanadium oxide in step (1) includes V2O3 and / or V2O5.

3. The preparation method according to claim 1, characterized in that The reduction temperature in step (1) is 700-1400°C.

4. The preparation method according to claim 3, characterized in that The reduction time is 0.25 to 24 hours.

5. The preparation method according to claim 1, characterized in that The reducing atmosphere is a vacuum atmosphere or a protective atmosphere.

6. The preparation method according to claim 5, characterized in that The reducing protective atmosphere includes any one of argon, hydrogen or helium, or a combination of at least two of them.

7. The preparation method according to claim 1, characterized in that The post-reduction wet treatment in step (2) comprises: slurrying the reduced material with water and / or acid solution to obtain slurry; adjusting the pH of the slurry and performing solid-liquid separation in sequence, washing and drying the obtained solid phase to obtain VAl x alloy.

8. The preparation method according to claim 7, characterized in that The pH of the acid solution in the post-reduction wet treatment is ≥0.

5.

9. The preparation method according to claim 7, characterized in that The liquid-to-solid ratio of slurry in the wet treatment after reduction is 1 to 100:1 mL / g.

10. The preparation method according to claim 7, characterized in that The acid used for pH adjustment in the wet treatment after reduction includes hydrochloric acid.

11. The preparation method according to claim 7, characterized in that In the pH adjustment process of the post-reduction wet treatment, the pH of the slurry is controlled to be ≥0.

8.

12. The preparation method according to claim 7, characterized in that The pH of the slurry after pH adjustment in the post-reduction wet treatment is stabilized at 1.5 to 3.

0.

13. The preparation method according to claim 7, characterized in that The washing temperature in the wet treatment after reduction is 0-60°C.

14. The preparation method according to claim 7, characterized in that The drying temperature in the post-reduction wet treatment is ≤60°C.

15. The preparation method according to any one of claims 1 to 14, characterized in that: The preparation method further comprises: (3) the VA1 x The alloy is deoxidized by a deoxidizer, wherein the deoxidizer includes calcium, to obtain a deoxidized material; (4) the deoxidized material is subjected to a post-deoxidation wet treatment to obtain VAl with a low oxygen content. x alloy.

16. The preparation method according to claim 15, characterized in that The VAl with low oxygen content x The oxygen content in the alloy is ≤0.20wt%.

17. The preparation method according to claim 15, characterized in that The VA1 x The mass ratio of the alloy to the deoxidizer is 1:0.05-0.

5.

18. The preparation method according to claim 15, characterized in that A deoxidation auxiliary agent is added in the deoxidation treatment.

19. The preparation method according to claim 18, characterized in that The deoxidation auxiliary agent includes any one of anhydrous CaCl2, CaCl2-MgCl2 eutectic salt, CaCl2-NaCl eutectic salt, CaCl2-KCl eutectic salt or CaCl2-LiCl eutectic salt, or a combination of at least two thereof.

20. The preparation method according to claim 18, characterized in that The deoxidation auxiliary agent and VAl x The weight ratio of the alloy is 0.05 to 3:

1.

21. The preparation method according to claim 15, characterized in that The temperature of the deoxidation treatment is 700-1100°C.

22. The preparation method according to claim 15, characterized in that The deoxidation treatment time is 0.25 to 48 hours.

23. The preparation method according to claim 15, characterized in that The atmosphere of the deoxidation treatment is a vacuum atmosphere or a protective atmosphere.

24. The preparation method according to claim 23, characterized in that The protective atmosphere for the deoxidation treatment includes any one of argon, hydrogen or helium, or a combination of at least two of them.

25. The preparation method according to claim 15, characterized in that The post-deoxidation wet treatment in step (3) includes: slurrying the deoxidized material with water and / or acid solution to obtain slurry; the slurry is sequentially pH-adjusted and solid-liquid separated, and the obtained solid phase is washed and dried to obtain VAl with low oxygen content. x alloy.

26. The preparation method according to claim 25, characterized in that The pH of the acid solution in the wet treatment after deoxidation is ≥0.

5.

27. The preparation method according to claim 25, characterized in that The liquid-to-solid ratio of slurry in the wet treatment after deoxidation is 1 to 100:1 mL / g.

28. The preparation method according to claim 25, characterized in that The acid used for pH adjustment in the wet treatment after deoxidation includes hydrochloric acid.

29. The preparation method according to claim 25, characterized in that The pH of the slurry is controlled to be ≥0.8 during the pH adjustment process in the wet treatment after deoxidation.

30. The preparation method according to claim 25, characterized in that The pH of the slurry after pH adjustment in the post-deoxidation wet treatment is 1.5-3.

0.

31. The preparation method according to claim 25, characterized in that The washing temperature in the wet treatment after deoxidation is 0-60°C.

32. The preparation method according to claim 25, characterized in that The drying temperature in the wet treatment after deoxidation is ≤60°C.

33. The preparation method according to claim 1, characterized in that The preparation method comprises the following steps: (1) Mixing vanadium oxide with CaO, a reducing agent and a reduction auxiliary agent, wherein the molar ratio of the reducing agent to the vanadium oxide is (2ax+2bx+10b / 3+2a):(a+b), where x is VAl x The alloy comprises the following components: x, a / (a+b) represents the molar ratio of vanadium trioxide in the vanadium oxide, b / (a+b) represents the molar ratio of vanadium pentoxide in the vanadium oxide, a molar ratio of CaO to the reducing agent is 0.6 to 2:1, and a weight ratio of the reduction auxiliary agent to the vanadium oxide is 0.05 to 3:

1. The alloy is reduced at 700 to 1400° C. for 0.25 to 24 hours under vacuum or protective atmosphere to obtain a raw material; the reducing agent comprises aluminum; (2) The reducing material is slurried with water and / or hydrochloric acid solution with a pH value of ≥0.5 to obtain a slurry; the slurry is pH-adjusted, and the pH value of the slurry is controlled to be ≥0.8 during the pH adjustment process. The pH value of the slurry after pH adjustment is stabilized at 1.5 to 3.0, and the solid-liquid separation is performed, and the obtained solid phase is washed at 0 to 60°C and dried at ≤60°C to obtain VAl x alloy, where x is in the range of 0.20≤x≤5.

80.

34. The preparation method according to claim 33, characterized in that The preparation method further comprises: (3) the VA1 x The alloy is deoxidized at 700-1100°C for 0.25-48h in a vacuum or protective atmosphere with a deoxidizer and a deoxidizer auxiliary agent, wherein the deoxidizer includes calcium, VAl x The mass ratio of alloy to deoxidizer is 1:0.05~0.5, and the mass ratio of deoxidizer to VAl x The weight ratio of the alloy is 0.05 to 3:1 to obtain a deoxidized material; (4) The deoxidized material is slurried with water and / or hydrochloric acid solution with a pH of ≥0.5 to obtain a slurry; the slurry is pH-adjusted, and the pH of the slurry is controlled to be ≥0.8 during the pH adjustment process. The pH of the slurry after pH adjustment is stabilized at 1.5-3.0, and solid-liquid separation is performed. The obtained solid phase is washed at 0-60°C and dried at ≤60°C to obtain VAl with an oxygen content of ≤0.20wt%. x alloy.

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