Preparation method of vanadium-aluminum alloy

Abstract

The invention relates to the technical field of metallurgy, and discloses a preparation method of a vanadium-aluminum alloy, which comprises the following steps: S1, proportioning vanadium pentoxide, aluminum particles, vanadium-aluminum alloy fine powder and lime in proportion, uniformly mixing, pouring into a smelting crucible, and placing on a smelting flat car; s2, igniting the material by using an ignition agent for smelting, and starting a flatcar vibration device after ignition; s3, continuously vibrating after the combustion reaction is finished; and S4, the smelting crucible is hoisted out and then naturally cooled, aftertreatment is conducted, the smelting crucible is poured into a mixing tank to be ground, screening and packaging are conducted, and a vanadium-aluminum alloy product is obtained. The method optimizes the process for smelting the vanadium-aluminum alloy through the aluminothermy method, the internal quality and production efficiency of the vanadium-aluminum alloy are remarkably improved in all links from burdening to aftertreatment, the problems of incomplete separation of pores, oxidation films and slag-metal in the traditional process are solved, a reliable guarantee is provided for batch production of the high-quality vanadium-aluminum alloy, and the method is suitable for large-scale production of the high-quality vanadium-aluminum alloy. And meanwhile, the requirements of aerospace and other fields on high-performance alloy materials are met.

Description

Technical Field

[0001] The invention relates to the technical field of metallurgy, and in particular to a method for preparing a vanadium-aluminum alloy. Background Art

[0002] Vanadium-aluminum master alloy is an indispensable and important additive raw material in the production of titanium alloy. With the rapid development of the aerospace industry, the demand and quality requirements for titanium alloy and high-end vanadium-aluminum alloy are also increasing. The aluminothermic method is a common method for smelting vanadium-aluminum alloy, but in the process of using vanadium pentoxide to react with metallic aluminum, due to the large heat release and strong thermal shock, internal pores, oxide films and incomplete slag-metal separation appear in the vanadium-aluminum alloy forming process, which has become the main problem of the aluminothermic method in the production of vanadium-aluminum alloy. These factors significantly reduce the finished product rate and yield of vanadium-aluminum alloy, while pushing up production costs, becoming the main challenge in the application of the aluminothermic method.

[0003] In the prior art, the relevant documents for preparing vanadium aluminum alloys are as follows: Patent CN110144507A discloses a method for controlling the generation of oxide film on vanadium-aluminum alloy, including: designing a heating device on the outer layer of the furnace body for smelting vanadium-aluminum alloy by electric aluminothermic method, assembling it on the furnace body platform, and placing the furnace body therein during smelting; after vanadium pentoxide, aluminum particles, and slag-making agent are mixed evenly, they are added to the smelting furnace, the electrode is ignited to start the aluminothermic reaction, and the electromagnetic coil power supply is turned on at the end of smelting to heat the furnace body, and the initial temperature is controlled at 450-600°C, maintained for 2-3h, and the mid-term temperature is controlled at 300-450°C, maintained for 1-2h, and then naturally cooled; the alloy is naturally cooled to 30-40°C, and the cooling is completed. The obtained alloy ingot is finely crushed to obtain a qualified vanadium-aluminum alloy. The method of using resistance wire heating to reduce the cooling speed of the alloy ingot in the later stage of cooling can effectively reduce the generation of oxide film on vanadium-aluminum alloy, but the temperature control range is small, the control effect is limited, and the equipment structure is complex, the energy consumption is high, and the operation is difficult.

[0004] Patent CN103484676A discloses a treatment method after the aluminothermic reduction reaction of an intermediate alloy. After the aluminothermic reduction reaction is completed, the intermediate alloy reaction raw material forms an alloy ingot and a slag ingot in the reaction container. The alloy ingot is at the bottom and the slag ingot is at the top. A gas layer is formed between the alloy ingot and the slag ingot. After the reaction is completed, the reaction container is moved to the post-reaction chamber to perform steel chisel slag breaking. The steel chisel is inserted from the surface of the slag ingot, passes through the slag ingot, reaches the gas layer, and then pulled out. The insertion and pulling out actions are repeated to release the high-pressure gas in the gas layer between the alloy ingot and the slag ingot. The high-pressure cavity between the alloy ingot and the slag layer is removed by using a steel chisel to break the slag. This method is difficult to operate, has a high risk factor, and has the risk of causing the alloy ingot to break.

[0005] It can be seen from the above patents that there are still many problems in improving the yield of vanadium aluminum alloy in the existing technology. Summary of the invention

[0006] In view of this, the purpose of the embodiment of the present invention is to propose a preparation method of vanadium aluminum alloy, optimize the process of smelting vanadium aluminum alloy by aluminothermic method, significantly improve the internal quality and production efficiency of vanadium aluminum alloy from ingredients to post-processing, solve the problems of pores, oxide film and incomplete separation of slag and gold in traditional processes, provide reliable guarantee for the mass production of high-quality vanadium aluminum alloy, improve the finished product rate, vanadium yield and production efficiency of vanadium aluminum alloy, reduce production costs, and meet the needs of aerospace and other fields for high-performance alloy materials.

[0007] Based on the above purpose, an embodiment of the present invention provides a method for preparing a vanadium aluminum alloy, comprising: S1, mixing vanadium pentoxide, aluminum particles, vanadium aluminum alloy fine powder and lime according to a certain proportion, pouring them into a smelting crucible after mixing, and placing them on a smelting flat car; S2, using ignition agent to ignite the material for smelting, and after ignition, turning on the flat car vibration device; S3, continue to vibrate after the combustion reaction is completed; S4, the smelting crucible is lifted out and cooled naturally, and then post-processed and poured into a mixing tank for grinding, sieving and packaging to obtain vanadium-aluminum alloy products.

[0008] According to one embodiment of the present invention, in step S2, the inclination angle of the flat car vibration device is 10-15°.

[0009] According to one embodiment of the present invention, in step S2, the vibration frequency of the flat car vibration device is 50-100 times / min.

[0010] According to one embodiment of the present invention, in step S2, the ignition agent is titanium powder.

[0011] According to one embodiment of the present invention, in step S3, the vibration continues for 20 to 30 minutes.

[0012] According to one embodiment of the present invention, in step S4, the natural cooling time is 20 to 24 hours.

[0013] According to one embodiment of the present invention, in step S4, post-processing includes furnace dismantling, coarse crushing, sandblasting and fine crushing.

[0014] According to one embodiment of the present invention, in step S4, the time of dermabrasion is 5 to 10 minutes.

[0015] According to one embodiment of the present invention, in step S1, the ingredients are mixed by a mixer for 5 minutes to be uniformly mixed.

[0016] According to one embodiment of the present invention, in step S1, the smelting crucible is a graphite crucible.

[0017] The present invention has at least the following beneficial technical effects: The present invention optimizes the process of smelting vanadium-aluminum alloy by aluminothermic method. Adding fine vanadium-aluminum alloy powder is beneficial to reducing thermal shock and reducing vanadium loss caused by splashing. Secondly, by adding high-quality lime to improve the slag system, the fluidity of the smelting slag is enhanced, which is beneficial to alloy precipitation and improves alloy separation efficiency. Then, in the smelting process from ignition to the end of the reaction, a small vibration is used for stirring, which is beneficial to alloy homogenization and gas escape, reduces the generation of pores and oxide film inside the alloy, improves the density of the alloy, and uses a mixing device for grinding after fine crushing, which improves quality assurance. The above process significantly reduces the deterioration quality problems of vanadium-aluminum alloy such as slag inclusion, oxide film and pores, improves the finished product rate, vanadium yield and production efficiency of vanadium-aluminum alloy, and reduces production costs. DETAILED DESCRIPTION

[0018] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the embodiments of the present invention are further described in detail below in conjunction with specific embodiments.

[0019] The terms "including" and "having" and any variations thereof in the specification and claims of the present invention are intended to cover non-exclusive inclusions; the terms "first", "second", etc. in the specification and claims of the present invention are used to distinguish different objects rather than to describe a specific order. "Multiple" means two or more, unless otherwise clearly and specifically defined.

[0020] In addition, reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0021] The present invention provides a method for preparing a vanadium aluminum alloy, comprising the following steps: S1, mixing vanadium pentoxide, aluminum particles, vanadium aluminum alloy fine powder and lime according to a certain proportion, pouring them into a smelting crucible after mixing, and placing them on a smelting flat car; S2, using ignition agent to ignite the material for smelting, and after ignition, turning on the flat car vibration device; S3, continue to vibrate after the combustion reaction is completed; S4, the smelting crucible is lifted out and cooled naturally, and then post-processed and poured into a mixing tank for grinding, sieving and packaging to obtain vanadium-aluminum alloy products.

[0022] According to one embodiment of the present invention, in step S1, vanadium pentoxide is the source of vanadium element and the main raw material of vanadium aluminum alloy. Aluminum particles are used as a reducing agent to reduce vanadium in vanadium pentoxide through aluminothermic reaction. Vanadium aluminum alloy fine powder is used to reduce the reaction heat shock, reduce splashing and uneven reaction, improve the uniformity of the finished product, and facilitate the reduction and alloying of vanadium. Lime uses high-quality lime as a slag-making material, and forms a slag layer together with alumina generated by aluminothermic reaction. The appropriate amount of lime added enhances the fluidity of the slag system, facilitates the separation of slag and alloy, and reduces the amount of slag inclusion. After the above raw materials are mixed according to the proportion, they are rotated and mixed for 5 minutes by a mixer to ensure that the reactants are fully contacted, avoid local unevenness causing low reaction efficiency, make the vanadium aluminum alloy fine powder evenly distributed, and help alleviate the uneven heat during the reaction. The evenly mixed ingredients are poured into a crucible, which is a graphite crucible. The graphite crucible is resistant to high temperature and chemical corrosion and is suitable for aluminothermic smelting. The loaded graphite crucible is placed on a smelting flat car for convenient subsequent operation and movement. The proportion of ingredients, in terms of mass percentage, can be: 49% to 51% vanadium pentoxide, 44% to 46% aluminum particles, 3.5% to 4% vanadium aluminum alloy fine powder, and 2% to 3% lime. The purity of vanadium pentoxide is ≥98%, and the purity of lime is ≥98%.

[0023] According to one embodiment of the present invention, in step S2, highly active titanium powder is used as an ignition agent, and the titanium powder can burn quickly at high temperature to trigger an aluminothermic reaction. The aluminothermic reaction of aluminum and vanadium pentoxide releases a large amount of heat, melts the reactants, vanadium and aluminum form a vanadium aluminum alloy, and aluminum oxide forms slag. After the reaction is ignited, the flat car vibration device vibrates slightly at an inclination angle of 10-15° and a frequency of 50-100 times / minute to promote stirring, which can enhance the mixing uniformity of the reactants, facilitate the complete alloying reaction, and reduce the pores generated during the reaction process, thereby improving the density of the alloy. Among them, the flat car vibration device is set at an inclination angle of 10-15°, which can effectively promote the flow and separation of the liquid alloy, optimize the smelting process, and set a vibration frequency of 50-100 times / minute without disturbing the reaction process, and can effectively disperse the gas and homogenize the material to prevent local overheating and inclusion problems.

[0024] According to one embodiment of the present invention, in step S3, after the thermite reaction is completed, the vanadium-aluminum alloy and the slag form obvious stratification, and the flat car vibration device needs to continue to vibrate for 20 to 30 minutes to further help the gas escape, reduce the pores in the alloy, and promote slag-liquid separation and gas release.

[0025] According to one embodiment of the present invention, in step S4, the smelted graphite crucible can be taken out using a lifting device and placed in a safe area to wait for cooling. The vanadium-aluminum alloy and slag begin to cool naturally, and the cooling time can be set to 20 to 24 hours to avoid rapid cooling and cause internal stress in the material, which helps to further stabilize the internal structure of the vanadium-aluminum alloy. After cooling, the vanadium-aluminum alloy is post-processed, including furnace dismantling, coarse crushing, sandblasting, fine crushing and grinding. Specifically, the cooled graphite crucible is removed, the vanadium-aluminum alloy and slag are taken out, and the cooled vanadium-aluminum alloy block is preliminarily crushed by the coarse crushing equipment for subsequent processing. The coarsely crushed vanadium-aluminum alloy is sandblasted to remove the oxide film on the surface and the attached slag to improve the purity of the vanadium-aluminum alloy. On the basis of sandblasting, the vanadium-aluminum alloy is further finely broken, and the vanadium-aluminum alloy is crushed to a specified particle size for subsequent screening and packaging. The finely broken vanadium-aluminum alloy is ground for 5 to 10 minutes using a mixing tank to remove the surface residue of the vanadium-aluminum alloy and improve the quality of the finished product. The vanadium-aluminum alloy after grinding is screened, and the finished products can be graded according to specifications to ensure consistency. The final finished products are bagged and sealed to complete the production preparation.

[0026] The above process of the present invention significantly improves the internal quality and production efficiency of vanadium aluminum alloy from batching to post-processing through the optimization design of the aluminothermic method, solves the problems of pores, oxide film and incomplete separation of slag and gold in traditional processes, provides reliable guarantee for the mass production of high-quality vanadium aluminum alloy, and meets the demand for high-performance alloy materials in the fields of aerospace and the like. Specifically, the present invention is conducive to reducing thermal shock and reducing the vanadium loss caused by splashing by adding vanadium aluminum alloy fine powder, improving the slag system by adding high-quality lime, enhancing the fluidity of smelting slag, facilitating alloy precipitation, and improving alloy separation efficiency, and then using small vibration to stir the smelting process from ignition to the end of the reaction, which is conducive to alloy homogenization and gas escape, reducing the generation of pores and oxide film inside the alloy, and improving the compactness of the alloy, and using a mixing device for grinding after fine breaking, improving quality assurance, improving the yield rate, vanadium yield and production efficiency of vanadium aluminum alloy, and reducing production costs.

[0027] According to one embodiment of the present invention, in step S2, the inclination angle of the flat car vibration device is 10-15°.

[0028] According to one embodiment of the present invention, in step S2, the vibration frequency of the flat car vibration device is 50-100 times / min.

[0029] According to one embodiment of the present invention, in step S2, the ignition agent is titanium powder.

[0030] According to one embodiment of the present invention, in step S3, the vibration continues for 20 to 30 minutes.

[0031] According to one embodiment of the present invention, in step S4, the natural cooling time is 20 to 24 hours.

[0032] According to one embodiment of the present invention, in step S4, post-processing includes furnace dismantling, coarse crushing, sandblasting and fine crushing.

[0033] According to one embodiment of the present invention, in step S4, the time of dermabrasion is 5 to 10 minutes.

[0034] According to one embodiment of the present invention, in step S1, the ingredients are mixed by a mixer for 5 minutes to be uniformly mixed.

[0035] According to one embodiment of the present invention, in step S1, the smelting crucible is a graphite crucible.

[0036] The present invention optimizes the process of smelting vanadium-aluminum alloy by aluminothermic method. Adding fine vanadium-aluminum alloy powder is beneficial to reducing thermal shock and reducing vanadium loss caused by splashing. Secondly, by adding high-quality lime to improve the slag system, the fluidity of the smelting slag is enhanced, which is beneficial to alloy precipitation and improves alloy separation efficiency. Then, in the smelting process from ignition to the end of the reaction, a small vibration is used for stirring, which is beneficial to alloy homogenization and gas escape, reduces the generation of pores and oxide film inside the alloy, improves the density of the alloy, and uses a mixing device for grinding after fine crushing, which improves quality assurance. The above process significantly reduces the deterioration quality problems of vanadium-aluminum alloy such as slag inclusion, oxide film and pores, improves the finished product rate, vanadium yield and production efficiency of vanadium-aluminum alloy, and reduces production costs.

[0037] The present invention is further explained below in conjunction with specific embodiments and comparative examples.

[0038] Example 1 (1) 200 kg of 98% powdered vanadium pentoxide, 180 kg of 999 aluminum particles, 15 kg of vanadium aluminum fine powder, and 98% lime are added to a mixing tank and mixed in a mixer for 5 minutes. The mixture is then poured into a graphite crucible and placed on a smelting cart.

[0039] (2) The flat car is tilted at an angle of 10°, with a frequency of 50 times / min, ignited, and the vibration device is turned on for 20 minutes to lift out the smelting crucible.

[0040] (3) Cool naturally for 22 hours, dismantle the furnace, coarsely crush, sandblast, and finely crush, then pour the material into the mixing tank for grinding for 5 minutes, sieving, and packaging. The vanadium aluminum alloy finished product rate is 74.6%, and the vanadium recovery rate is 96.1%.

[0041] Example 2 (1) 200 kg of 98% powdered vanadium pentoxide, 180 kg of 999 aluminum particles, 15 kg of vanadium aluminum fine powder, and 98% lime are added to a mixing tank and mixed in a mixer for 5 minutes. The mixture is then poured into a graphite crucible and placed on a smelting cart.

[0042] (2) The flat car is tilted at an angle of 10° and the frequency is 100 times / min. Ignition is started and the vibration device is turned on for 20 minutes. The smelting crucible is then lifted out.

[0043] (3) Cool naturally for 22 hours, dismantle the furnace, coarsely crush, sandblast, and finely crush, then pour the material into the mixing tank for grinding for 8 minutes, sieving, and packaging. The vanadium aluminum alloy finished product rate is 75.4%, and the vanadium recovery rate is 96.3%.

[0044] Example 3 (1) 200 kg of 98% powdered vanadium pentoxide, 180 kg of 999 aluminum particles, 15 kg of vanadium aluminum fine powder, and 98% lime are added to a mixing tank and mixed in a mixer for 5 minutes. The mixture is then poured into a graphite crucible and placed on a smelting cart.

[0045] (2) The flat car is tilted at an angle of 10°, with a frequency of 150 times / min, ignited, and the vibration device is turned on for 20 minutes to lift out the smelting crucible.

[0046] (3) Cool naturally for 22 hours, dismantle the furnace, coarsely crush, sandblast, and finely crush, then pour the material into the mixing tank for grinding for 10 minutes, sieving, and packaging. The vanadium aluminum alloy finished product rate is 74.9%, and the vanadium recovery rate is 96.2%.

[0047] The present invention optimizes the process of smelting vanadium-aluminum alloy by aluminothermic method. Adding fine vanadium-aluminum alloy powder is beneficial to reducing thermal shock and reducing vanadium loss caused by splashing. Secondly, by adding high-quality lime to improve the slag system, the fluidity of the smelting slag is enhanced, which is beneficial to alloy precipitation and improves alloy separation efficiency. Then, in the smelting process from ignition to the end of the reaction, a small vibration is used for stirring, which is beneficial to alloy homogenization and gas escape, reduces the generation of pores and oxide film inside the alloy, improves the density of the alloy, and uses a mixing device for grinding after fine crushing, which improves quality assurance. The above process significantly reduces the deterioration quality problems of vanadium-aluminum alloy such as slag inclusion, oxide film and pores, improves the finished product rate, vanadium yield and production efficiency of vanadium-aluminum alloy, and reduces production costs.

[0048] The above are exemplary embodiments disclosed in the present invention, but it should be noted that various changes and modifications may be made without departing from the scope disclosed in the embodiments of the present invention as defined in the claims. The functions, steps and / or actions of the method claims according to the disclosed embodiments described herein do not need to be performed in any particular order. In addition, although the elements disclosed in the embodiments of the present invention may be described or required in individual form, they may also be understood as multiple unless explicitly limited to the singular.

[0049] It should be understood that, as used herein, the singular forms "a", "an" are intended to include the plural forms 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 including one or more of the associated listed items.

[0050] The serial numbers of the embodiments disclosed in the above embodiments of the present invention are only for description and do not represent the advantages or disadvantages of the embodiments.

[0051] A person skilled in the art should understand that the discussion of any of the above embodiments is only exemplary and is not intended to imply that the scope of the disclosure of the embodiments of the present invention (including the claims) is limited to these examples; under the concept of the embodiments of the present invention, the technical features in the above embodiments or different embodiments can also be combined, and there are many other changes in different aspects of the above embodiments of the present invention, which are not provided in detail for the sake of simplicity. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the embodiments of the present invention should be included in the protection scope of the embodiments of the present invention.

Claims

1. A method for preparing a vanadium aluminum alloy, characterized in that: include: S1, mixing vanadium pentoxide, aluminum particles, vanadium aluminum alloy fine powder and lime according to a certain proportion, pouring them into a smelting crucible after mixing, and placing them on a smelting flat car; S2, using ignition agent to ignite the material for smelting, and after ignition, turning on the flat car vibration device; S3, continue to vibrate after the combustion reaction is completed; S4, the smelting crucible is lifted out and cooled naturally, and then post-processed and poured into a mixing tank for grinding, screening and packaging to obtain vanadium aluminum alloy products.

2. The method according to claim 1, characterized in that In step S2, the inclination angle of the flat car vibration device is 10-15°.

3. The method according to claim 1, characterized in that In step S2, the vibration frequency of the flat car vibration device is 50-100 times / min.

4. The method according to claim 1, characterized in that: In step S2, the ignition agent is titanium powder.

5. The method according to claim 1, characterized in that In step S3, the vibration is continued for 20 to 30 minutes.

6. The method according to claim 1, characterized in that In step S4, the natural cooling time is 20 to 24 hours.

7. The method according to claim 1, characterized in that In step S4, post-processing includes furnace dismantling, coarse crushing, sandblasting and fine crushing.

8. The method according to claim 1, characterized in that In step S4, the time of the skin grinding is 5 to 10 minutes.

9. The method according to claim 1, characterized in that: In step S1, the ingredients are mixed by a mixer for 5 minutes to be uniformly mixed.

10. The method according to claim 1, characterized in that In step S1, the smelting crucible is a graphite crucible.