Method for preparing niobium-aluminum alloy through molten salt electrolysis of cerium-niobium-perovskite

Abstract

The invention relates to the technical field of electrochemical metallurgy, in particular to a method for preparing niobium-aluminum alloy through molten salt electrolysis of cerium-niobium-perovskite, which comprises the following steps: placing raw material aluminum at the bottom of an electrolytic bath; uniformly mixing the raw material ore and the fused salt, and placing in an electrolytic bath; the bottom of the electrolytic cell is heated, and after temperature rise and heat preservation are conducted, the raw material aluminum is molten into liquid aluminum; after heat preservation is finished, the bottom of the electrolytic cell is heated, liquid aluminum serves as a cathode, a graphite rod serves as an anode, after a direct-current power source is connected, constant-voltage electrolysis is conducted according to preset power source voltage, and an electrolysis product is obtained; and the obtained electrolysis product is crushed and levigated, and the niobium-aluminum alloy and residual fused salt are obtained. According to the method provided by the invention, gradient electrolysis and element separation between niobium and titanium are realized through accurate control of electrochemical conditions, and comprehensive extraction and utilization of various metals in associated ore or metallurgical slag containing rare earth, niobium and titanium are realized while the niobium-aluminum alloy and the niobium-titanium-aluminum alloy are prepared.

Description

Technical Field

[0001] The present invention relates to the technical field of electrochemical metallurgy, and in particular to a method for preparing niobium aluminum alloy by molten salt electrolysis of cerium niobium perovskite. Background Art

[0002] Niobium is a rare metal that is of great strategic significance to national security and the development of emerging industries. Due to the excellent physical, chemical and mechanical properties of niobium and its related compounds, they are widely used in steel, aviation, aerospace, navigation, chemical industry, construction and medicine, and are indispensable in modern industry and cutting-edge technology.

[0003] The Bayan Obo Mine is a world-renowned multi-metallic symbiotic ore that integrates rare earths, iron, niobium, titanium and other important elements. The reserves of rare earth resources rank first in the world, and the reserves of niobium resources rank second in the world. However, the development and utilization of Bayan Obo mineral resources have always been mainly based on iron, the comprehensive utilization rate of rare earth resources is less than 10%, and the comprehensive utilization rate of niobium resources is almost zero. The niobium grade of the Bayan Obo Mine is about 0.10%, and it contains as many as 20 niobium ore phases, with a particle size generally not exceeding 20μm. Due to the poor, mixed and fine characteristics of the Bayan Obo ore phase, and the symbiosis or wrapping with other ore phases, separation and extraction are extremely difficult. In particular, niobium and titanium have similar chemical properties. The two are widely symbiotic in a variety of niobium-containing ore phases in a isomorphic manner, and are inherited in the beneficiation process of niobium resources, which seriously affects the concentrate grade and product quality.

[0004] China Patent Publication No. CN116240590A discloses "a method for preparing niobium-titanium alloy by molten salt electrolysis", which is a process for preparing niobium-titanium alloy by electrolysis by dissolving titanium tetrachloride and niobium pentachloride in chloride molten salt. China Patent Publication No. CN115717254A discloses "a method for preparing high-purity metallic niobium by molten salt electrolysis", which uses the prepared niobium carbon-based solid solution as a soluble anode and graphite as a cathode to prepare metallic niobium by electrolysis in a chloride molten salt system. China Patent Publication No. CN116463683A discloses "a method for separating metallic niobium and titanium by electrolysis using a soluble anode", which uses the prepared niobium carbon-based solid solution and titanium carbon-based solid solution as anodes and places them in two chloride electrolyte systems for electrolysis, thereby achieving the separation of niobium and titanium. China Patent Publication No. CN115305521A discloses "a method for preparing metallic niobium by molten salt electrolysis", which uses liquid niobium alloy to separate the electrolytic cell into a cathode cell and an anode cell, and then performs electrolysis to prepare metallic niobium.

[0005] The above patented technologies all use molten salt electrolysis to achieve the purpose of preparing metallic niobium or separating niobium and titanium. However, they do not consider the low solubility of niobium and titanium in molten salt, which results in low current efficiency and poor electrolysis effect; the preparation process of using niobium and titanium carbon-based solid solution as cathode is complicated, and a large amount of carbon monoxide or carbon dioxide will be released during the electrolysis process as the target product is deposited, so it is difficult to achieve large-scale production; and the above methods do not electrolyze and separate minerals where niobium and titanium coexist, so the effect in actual production applications is not considered.

[0006] Chinese patent publication number CN105385866A discloses "a method and system for preparing niobium aluminum alloy". This method uses aluminothermic reduction reaction to make the metal niobium generated by the reaction evenly distributed in the aluminum liquid, and react with excess aluminum to form niobium aluminum alloy. Chinese patent publication number CN115478200A "Niobium aluminum alloy and its preparation method" discloses that after the niobium source, aluminum source, slag-making agent and heating agent are fully mixed, aluminothermic reaction occurs to prepare niobium aluminum alloy. Chinese patent publication number CN104674067A discloses "a method for producing niobium aluminum alloy". This method uses pure main element niobium, that is, niobium aluminum intermediate alloy with a melting point of about 1690°C for smelting to obtain niobium aluminum alloy.

[0007] The above methods all utilize aluminothermic reduction reaction to prepare niobium aluminum alloy. However, the above methods cannot overcome the problem of co-reduction of other metals, and therefore cannot solve the problem of separation of metal elements in complex co-existing ores. Summary of the invention

[0008] 1. Technical issues to be resolved In view of the shortcomings of various existing technologies for extracting niobium from the Bayan Obo mine tailings, there is still no technical problem of effective recycling and utilization.

[0009] (II) Technical solution To this end, the present invention discloses a method for preparing niobium aluminum alloy by molten salt electrolysis of cerium niobium perovskite, comprising: Step 1: Place the raw aluminum at the bottom of the electrolytic cell; Step 2: Mix the raw ore and molten salt in a mass ratio of (1-10):100 and place them in the electrolytic cell; Step 3: heating the bottom of the electrolytic cell to a first preset temperature and then maintaining the temperature for a first preset time to melt the raw aluminum into liquid aluminum; Step 4: After the insulation is completed, the temperature at the bottom of the electrolytic cell is raised to a second preset temperature, the liquid aluminum is used as the cathode, the graphite rod is used as the anode, and after connecting a DC power supply, constant voltage electrolysis is performed according to a preset power supply voltage to obtain an electrolysis product; Step 5: Crushing and grinding the obtained electrolytic products to obtain niobium aluminum alloy and residual molten salt.

[0010] Furthermore, in step 4, the preset power supply voltage is lower than the decomposition voltage of the molten salt system, rare earth and titanium oxides, and higher than the decomposition voltage of niobium oxides.

[0011] Furthermore, in step 2, the molten salt is a mixture of Na3AlF6 and at least one of NaF, LiF or KF.

[0012] Furthermore, in the molten salt, the mass ratio of Na3AlF6 to at least one of NaF, LiF or KF is (7:3)-(5:5).

[0013] Furthermore, the preset power supply voltage is 2-5V.

[0014] Further, in step 2, based on the sum of the mass percentages being 100%, the composition of the raw ore includes: REO is 38%-46%, Nb2O5 is 13%-17%, TiO is 29%-37%, and the remainder is unavoidable impurities.

[0015] Furthermore, in step 3, a preset flow rate of inert gas is introduced for atmosphere protection.

[0016] Further, in step 4, the constant voltage electrolysis is performed for a second preset time, which is 1-5 hours.

[0017] Furthermore, in step 5, after the electrolysis is completed, the cathode, the anode and the molten salt are cooled under the protection of an inert gas.

[0018] Furthermore, in step 5, the residual molten salt contains rare earth and titanium, which are used for separation and extraction of rare earth and titanium.

[0019] (III) Beneficial effects The beneficial effects of the present invention are as follows: the present invention provides a method for preparing niobium aluminum alloy by molten salt electrolysis of cerium niobium perovskite, comprising: placing raw aluminum at the bottom of an electrolytic cell; mixing the raw ore and molten salt in a mass ratio range of (1-10):100 and placing the mixture in the electrolytic cell; heating the bottom of the electrolytic cell to a first preset temperature, and then maintaining the temperature for a first preset time to melt the raw aluminum into liquid aluminum; after the insulation is completed, the temperature of the bottom of the electrolytic cell is increased to a second preset temperature, the liquid aluminum is used as a cathode, the graphite rod is used as an anode, a DC power supply is connected, and constant voltage electrolysis is performed according to a preset power supply voltage to obtain an electrolysis product; the obtained electrolysis product is crushed and ground to obtain a niobium aluminum alloy and residual molten salt.

[0020] The method for preparing niobium aluminum alloy by molten salt electrolysis of cerium niobium perovskite mentioned in the present invention uses low melting point metal aluminum as liquid cathode, has low operation difficulty, effectively avoids the problem of dendrite growth of niobium products, avoids the formation of niobium carbide and titanium carbide, and solves related problems such as low electrolysis efficiency. Continuous electrolysis separation and extraction are carried out by adding raw materials, and niobium aluminum alloy and niobium titanium aluminum alloy are successfully obtained. Through the precise control of electrochemical conditions, step electrolysis and element separation between niobium and titanium are achieved. By regulating the preset voltage, step electrolysis can be carried out in the order of niobium, titanium, and rare earth, and selective reduction of niobium and titanium is achieved to prepare niobium aluminum alloy and niobium titanium aluminum alloy. The phase separation of different key metals is achieved by diffusion of selectively precipitated metals between molten salt and liquid cathode. While completing the separation of niobium and titanium, niobium aluminum alloy and niobium titanium aluminum alloy are prepared, and the comprehensive extraction and utilization of multiple metals in co-existing ores or metallurgical slag containing rare earth, niobium, and titanium are realized. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A theoretical decomposition voltage diagram for a method for preparing niobium aluminum alloy by molten salt electrolysis of cerium niobium perovskite mentioned in this application; Figure 2 A process flow chart of a method for preparing niobium aluminum alloy by molten salt electrolysis of cerium niobium perovskite mentioned in this application; Figure 3 This is a crystal structure diagram of a raw material for a method of preparing niobium aluminum alloy by molten salt electrolysis of cerium niobium perovskite mentioned in this application. DETAILED DESCRIPTION

[0022] In order to better explain the present invention and facilitate understanding, the present invention is described in detail below through specific implementation modes in conjunction with the accompanying drawings.

[0023] When amount, concentration or other value or parameter is represented by range, preferred range or a series of upper preferred value and lower preferred value, this should be understood as specifically disclosing all ranges formed by any pairing of any range upper limit or preferred value and any range lower limit or preferred value, regardless of whether the range is disclosed separately. For example, when disclosing range "1-5", described range should be interpreted as including range "1-4", "1-3", "1-2", "1-2 and 4-5", "1-3 and 5" etc. When numerical range is described in this article, unless otherwise stated, the range is intended to include its end value and all integers and fractions within the range.

[0024] In these embodiments, unless otherwise specified, the parts and percentages are all by mass. "Parts by mass" refers to the basic unit of measurement representing the mass ratio of multiple components, and 1 part can represent any unit mass, such as 1 g, 3.527 g, etc. If we say that the mass parts of component A are a parts and the mass parts of component B are b parts, it means the ratio of the mass of component A to the mass of component B a:b. Alternatively, it means that the mass of component A is aK and the mass of component B is bK (K is an arbitrary number, indicating a multiple factor). It should not be misunderstood that, unlike the mass parts, the sum of the mass parts of all components is not limited to 100 parts. "And / or" is used to indicate that one or both of the situations described may occur, for example, A and / or B include (A and B) and (A or B).

[0025] It should be noted that niobium and titanium have similar chemical properties and close ionic radii, forming a wide range of isomorphism in the Bayan Obo mine, which makes it difficult to separate, and the purity of niobium products is insufficient, thus limiting their application. In addition, due to the complexity and particularity of the Bayan Obo mineral composition, it is inevitable that there will be invalid cycles of repeated transformation of element occurrence forms and multiple switching of energy loading and unloading in the high-temperature-low-temperature process during the processing process. At the same time, decomposition, leaching, calcination and other processes often emit a large amount of highly polluting wastewater and waste gas, causing environmental pollution. Therefore, it is necessary to develop a new process to achieve deep separation of elements by relying on the differences in the electrochemical behaviors of different key metals, and follow the design concept of integrated metallurgical materials to achieve cross-integration of metallurgical separation and transformation and alloy material preparation.

[0026] from Figure 1 In the diagram of theoretical decomposition voltages at different temperatures shown, it is found that the theoretical decomposition voltages of titanium oxide and rare earth oxide are above the theoretical decomposition voltages of niobium oxide and iron oxide. By controlling the voltage, a selective electrolysis can be carried out between niobium and titanium to separate and precipitate niobium and titanium, thereby preparing niobium aluminum alloy.

[0027] refer to Figure 2 The present invention provides a method for preparing niobium aluminum alloy by molten salt electrolysis of cerium niobium perovskite, comprising: Step 1: Place the raw aluminum at the bottom of the electrolytic cell.

[0028] It should be noted that the use of aluminum metal as a liquid cathode is simple to operate, can effectively avoid the growth of niobium product dendrites, and directly prepare niobium aluminum alloy. When aluminum metal is used as a liquid cathode, the liquid cathode can provide a larger reaction area during the electrolysis process, which is conducive to the reaction. At the same time, avoiding dendrite growth can improve the quality and stability of the product.

[0029] Exemplarily, the raw aluminum is metallic aluminum. 10-50 g of metallic aluminum can be placed at the bottom of the electrolytic cell.

[0030] Step 2: Mix the raw ore and molten salt in a mass ratio of (1-10):100 and place them in the electrolytic cell.

[0031] In a feasible implementation, in step 2, the composition of the raw material ore includes REO: 38%-46%, Nb2O5: 13%-17%, TiO2: 29%-37%, and the remainder is unavoidable impurities, based on the sum of the mass percentages as 100%. The raw material ore contains components such as cerium niobium perovskite, including REO (rare earth oxide), niobium oxide, titanium oxide, etc., which have a higher grade and serve as a source of the target metal. Due to the different solubility and reactivity of different raw material ore components in molten salt, the raw material ore and molten salt are selected in a mass ratio range of (1-10): 100, so that there are enough reactants to participate in the reaction during the electrolysis process, while avoiding excessive viscosity of the molten salt system due to excessive raw materials, which affects the migration of ions and the reaction.

[0032] It should be noted that the method for preparing niobium aluminum alloy by molten salt electrolysis of cerium niobium perovskite mentioned in the present invention uses cerium niobium perovskite with a similar crystal structure to perovskite as an electrolytic raw material, and utilizes its easily dissociated crystal structure to have a higher solubility in the molten salt system, thereby solving the problem of low solubility of niobium and titanium oxides in the molten salt system, thereby improving the current efficiency. By utilizing the fact that there is a certain difference in the theoretical decomposition voltage required for the reduction of niobium and titanium oxides to metals, selective electrolytic reduction between different metals is achieved through potential control, and phase separation of different key metals is achieved by diffusion of selectively precipitated metals between the molten salt and the liquid cathode.

[0033] refer to Figure 3 , Figure 3 The figure shows the crystal structure of the raw material cerium niobium perovskite niobium, which has a crystal structure of ((Ca, Ce) (Ni, Ti) O3). Such a crystal structure has higher solubility and easy dissociation in the sodium fluoride-cryosolite molten salt system, and can achieve rapid migration and diffusion of alkali metal cations and oxygen-containing acid anions, thereby solving the problem of low solubility of niobium and titanium oxides in molten salts.

[0034] In a feasible implementation, in step 2, the molten salt is a mixture of Na3AlF6 and at least one of NaF, LiF or KF. In the molten salt, the mass ratio of Na3AlF6 to at least one of NaF, LiF or KF is (7:3)-(5:5).

[0035] Molten salt acts as an electrolyte to provide an environment for ion conduction. The molten salt system formed by mixing Na3AlF6 with at least one of NaF, LiF or KF has suitable properties such as melting point, viscosity and conductivity, which can ensure the smooth migration of ions and the progress of the reaction during the electrolysis process.

[0036] The molten salt needs to be sufficient to dissolve a certain proportion of the raw material ore, ionize it, and form ionic substances that can be used for electrolysis. At the same time, the molten salt also plays a role in transferring heat and maintaining the reaction temperature.

[0037] Mixing the raw material ore with the molten salt can make the raw material ore evenly distributed in the molten salt, avoiding local concentrations that are too high or too low, thereby improving the uniformity of the reaction.

[0038] During the electrolysis process, the migration speed and reaction activity of ions in the molten salt are affected by the concentration gradient. Uniform distribution can reduce the concentration gradient and make the reaction proceed more smoothly.

[0039] Evenly distributed raw material ore is also conducive to heat transfer, avoiding local overheating or overcooling and maintaining a stable reaction temperature.

[0040] The ions in the molten salt interact with the components in the raw material ore to promote the ionization and dissolution of the raw material ore. For example, the cations in the molten salt can react with the oxides in the raw material ore to form ionic metal and oxygen ions. The mixing process can increase the contact area between the raw material ore and the molten salt, accelerate the ionization and dissolution process, and improve the efficiency of the reaction.

[0041] The present application selects a molten salt system and mass ratio of Na3AlF6 and at least one of NaF, LiF or KF in a mass ratio of (7:3) to (5:5), and can utilize the fact that there is a certain difference in the theoretical decomposition voltage required for the reduction of niobium and titanium oxides to metals, to achieve selective electrolytic reduction between different metals. The molten salt system and mass ratio can adjust the concentration and activity of ions in the molten salt, thereby affecting the reduction potential of different metal ions.

[0042] In a feasible implementation, the preset power supply voltage is lower than the decomposition voltage of the molten salt system, rare earth and titanium oxides, and higher than the decomposition voltage of niobium oxide. The electrolysis method adopts constant voltage electrolysis, and the electrolysis range is 2-5V. Under the preset power supply voltage, only niobium oxide is reduced, while the molten salt system, rare earth and titanium oxide are not reduced, and phase separation can be achieved. Improving the current efficiency and realizing the selective electrolytic reduction and phase separation of different metals are conducive to the subsequent extraction of different metal components and improving the comprehensive utilization rate of resources.

[0043] Step 3: Heat the bottom of the electrolytic cell to a first preset temperature, and then keep it warm for a first preset time to melt the raw aluminum into liquid aluminum. The present application heats the raw aluminum to a melting point and turns it into liquid. In preparation for the subsequent electrolytic reaction as a cathode, the liquid aluminum can react better with cations and improve the reaction efficiency.

[0044] Exemplarily, the first preset temperature is 700° C.-900° C., and the first preset time is 0.5-3 hours, so that the metal aluminum is completely melted to serve as the cathode.

[0045] In a feasible implementation, in step 3, an inert gas with a preset flow rate is passed for atmosphere protection. For example, the inert gas may be high-purity argon gas, and the preset flow rate may be 0.5 L / min-1.5 L / min.

[0046] Under high temperature conditions, aluminum and metals that may be generated during the electrolysis process easily react with oxygen in the air and are oxidized. The introduction of high-purity argon gas can form an inert atmosphere in the electrolytic cell, preventing aluminum and other metals from contacting with oxygen and preventing oxidation reactions. Controlling the flow rate of argon gas within the range of 0.5L / min - 1.5L / min can ensure effective atmosphere protection while preventing excessive airflow from interfering with the electrolysis system. If the flow rate is too small, impurity gases such as oxygen cannot be fully removed, and if the flow rate is too large, it may cause problems such as molten salt splashing and temperature instability.

[0047] Step 4: After the insulation is completed, the temperature at the bottom of the electrolytic cell is raised to a second preset temperature. Liquid aluminum is used as the cathode and the graphite rod is used as the anode. After connecting a DC power supply, constant voltage electrolysis is performed according to the preset power supply voltage to obtain an electrolysis product.

[0048] It should be noted that the second preset temperature is the electrolysis temperature. For example, the electrolysis temperature is 700-1100°C. Increasing the temperature can increase the migration speed and reaction activity of the ions, so that the electrolysis reaction can proceed faster. Increasing the temperature can ensure that the molten salt maintains good fluidity during the electrolysis process so that the ions can migrate smoothly therein. If the temperature is too low, the molten salt will become too viscous, affecting the conduction of the ions and the reaction.

[0049] Under the action of direct current, an oxidation reaction occurs at the anode, and the graphite rod loses electrons. A reduction reaction occurs at the cathode, and the cations gain electrons at the liquid aluminum cathode and are reduced to metals. The preset power supply voltage is lower than the decomposition voltage of the molten salt system, rare earth and titanium oxides, and higher than the decomposition voltage of niobium oxide, so that only niobium oxide is reduced, achieving selective electrolytic reduction. Setting the preset power supply voltage can selectively reduce niobium oxide to prepare niobium aluminum alloy, avoid the reduction of other unnecessary metals, and improve the purity and pertinence of the product.

[0050] In a feasible implementation manner, in step 4, the constant voltage electrolysis is performed for a second preset time, and the second preset time is 1-5 hours.

[0051] Step 5: crush and grind the electrolysis product to obtain niobium aluminum alloy and residual molten salt. In a feasible implementation, in step 5, after the electrolysis is completed, the cathode, anode and molten salt are cooled under the protection of an inert gas.

[0052] In a feasible implementation manner, in step 5, the residual molten salt contains rare earth and titanium, which is used for separation and extraction of rare earth and titanium.

[0053] Exemplarily, the electrolysis product can be separated into niobium aluminum alloy and residual molten salt by physical crushing. Crushing and grinding can facilitate the subsequent further processing and utilization of niobium aluminum alloy. The residual molten salt contains rare earth and titanium, which can be used for the separation and extraction of rare earth and titanium, thereby improving the comprehensive utilization rate of resources. In addition, in step 3, an inert gas is passed through the atmosphere for protection, which can prevent aluminum and other metals from being oxidized at high temperatures and ensure the smooth progress of the reaction. After the electrolysis is completed in step 5, the cathode, anode and molten salt are cooled under the protection of an inert gas, also to prevent the metal from being oxidized and maintain the quality of the product.

[0054] This application uses the oxygen-containing salt structure of cerium niobium perovskite to solve the problem of low solubility of niobium and titanium oxides in molten salts. Cerium niobium perovskite has a spatial structure with higher solubility and dissociation in the molten salt system, which can realize the rapid migration and diffusion of alkali metal cations and oxygen-containing acid anions, and meets the limiting current diffusion density and current efficiency required by industry.

[0055] The present invention uses a liquid metal cathode to overcome the problem of dendrite growth of refractory metal electrolysis products. It promotes the in-situ electrochemical conversion of niobium-containing ion groups on the surface of the liquid cathode and diffuses into the cathode, avoids the dendrite growth of niobium products, and realizes the direct preparation of products such as Nb-Al alloy and Nb-Ti-Al alloy.

[0056] The present invention realizes the step electrolysis and element separation between niobium and titanium by precise control of electrochemical conditions. Step electrolysis can be carried out in the order of niobium, titanium and rare earth by regulating the voltage of the electrolytic cell, and the phase separation of different key metals can be achieved by diffusion of the selectively precipitated metals between the molten salt and the liquid cathode.

[0057] In order to better understand the technical solution, exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a clearer and more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0058] Example 1 Step 1: Place aluminum metal at the bottom of the electrolytic cell.

[0059] Step 2: Mix NaF-Na3AlF6 according to the mass percentage of 42% and 58% respectively, add 8% cerium niobium perovskite, the composition content of which is: w(REO): 46%, w(Nb2O5): 13%, w(TiO2): 35%, and place the mixed molten salt in a high-purity graphite electrolytic cell.

[0060] Step 3: Heat the electrolytic cell to 700°C and keep it warm for 2 hours to allow the metallic aluminum to completely melt into liquid form as the aluminum cathode. Inert gas is continuously introduced during the process.

[0061] Step 4: Liquid aluminum is used as cathode and high-purity graphite as anode. After insulation, the temperature is raised to the electrolysis temperature of 800°C, and the cell voltage is set to 2.5V for constant voltage electrolysis for 2 hours.

[0062] Step 5: After the electrolysis is completed, the electrodes and molten salt are cooled in an inert gas atmosphere and then taken out. During the electrolysis process, niobium ions migrate to the surface of the liquid aluminum metal at the bottom, obtain electrons, and are reduced to metallic niobium. The precipitated niobium continues to diffuse into the liquid aluminum metal and is quickly wrapped to form a niobium aluminum alloy. After the alloy is fully crushed and ground, it is rinsed with distilled water several times, and then dried at low temperature to detect the composition. The contents of Nb and Al in the alloy account for 13% and 75% respectively, and the remaining components are impurities. The effect of niobium and titanium separation is successfully achieved, and selective electrolytic precipitation is realized, and niobium aluminum alloy is directly prepared.

[0063] Example 2 Step 1: Place aluminum metal at the bottom of the electrolytic cell.

[0064] Step 2: Mix NaF-Na3AlF6 according to the mass percentage of 42% and 58% respectively, add 8% cerium niobium perovskite, the composition content of which is: w(REO): 38%, w(Nb2O5): 16%, w(TiO2): 29%, and place the mixed molten salt in a high-purity graphite electrolytic cell.

[0065] Step 3: Heat the electrolytic cell to 700°C and keep it warm for 2 hours to allow the metallic aluminum to completely melt into liquid form as the aluminum cathode. Inert gas is continuously introduced during the process.

[0066] Step 4: Liquid aluminum is used as cathode and high-purity graphite as anode. After heat preservation, the temperature is raised to the electrolysis temperature of 850°C, and the cell voltage is set to 3.0V for constant voltage electrolysis for 2 hours.

[0067] Step 5: After the electrolysis is completed, the electrodes and molten salt are cooled in an inert gas atmosphere and then taken out. During the electrolysis process, niobium ions migrate to the surface of the bottom liquid aluminum metal, obtain electrons, and are reduced to metallic niobium. The precipitated niobium continues to diffuse into the liquid aluminum metal and is quickly wrapped to form a niobium aluminum alloy. After the alloy is fully crushed and ground, it is rinsed with distilled water several times, and then dried at low temperature to detect the composition. The content of Nb and Al in the alloy accounts for 18% and 71% respectively, and the remaining components are impurities. The effect of niobium and titanium separation is successfully achieved, and selective electrolytic precipitation is realized, and niobium aluminum alloy is directly prepared.

[0068] Example 3 Step 1: Place aluminum metal at the bottom of the electrolytic cell.

[0069] Step 2: Mix NaF-Na3AlF6 according to the mass percentage of 38% and 62% respectively, add 10% cerium niobium perovskite, the composition content of which is: w(REO): 43%, w(Nb2O5): 17%, w(TiO2): 37%, and place the mixed molten salt in a high-purity graphite electrolytic cell.

[0070] Step 3: Heat the graphite electrolytic cell to 700°C and keep it warm for 2 hours to allow the metallic aluminum to completely melt into liquid form as an aluminum cathode. Inert gas is continuously introduced during the process.

[0071] Step 4: Liquid aluminum is used as cathode and high-purity graphite as anode. After insulation, the temperature is raised to the electrolysis temperature of 900°C, and the cell voltage is set to 4V for constant voltage electrolysis for 4 hours.

[0072] Step 5: After the electrolysis is completed, the electrodes and molten salt are cooled in an inert gas atmosphere and then taken out. During the electrolysis process, niobium and titanium ions migrate to the surface of the bottom liquid aluminum metal, obtain electrons, and are reduced to metal niobium and metal titanium. The precipitated metals continue to diffuse into the liquid aluminum metal and are quickly wrapped to form niobium aluminum alloy and niobium titanium aluminum alloy. After the alloy is fully crushed and ground, it is rinsed with distilled water several times, and the composition is tested after low-temperature drying. The contents of Nb, Ti and Al in the alloy are 14%, 27% and 48% respectively, achieving selective electrolysis and directly preparing niobium titanium aluminum alloy.

[0073] The above describes the basic principles, main features and advantages of the present invention. However, the above is only a specific embodiment of the present invention, and the technical features of the present invention are not limited thereto. Any other implementation methods derived by any technician in the field without departing from the technical solution of the present invention should be included in the patent scope of the present invention.

[0074] In the description of the present invention, each embodiment focuses on the differences from other embodiments, and the same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0075] In the description of the present invention, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically limited. Moreover, the term "includes", "comprising" or any other variant thereof is intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements not only includes those elements, but also includes other elements not clearly listed, or also includes elements inherent to such process, method, article or equipment. In the absence of more restrictions, the elements limited by the sentence "comprising one..." do not exclude the existence of other identical elements in the process, method, article or equipment including the elements.

[0076] In the present invention, unless otherwise clearly specified and limited, when a first feature is “on” or “below” a second feature, it may be that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, when a first feature is “above”, “above” or “above” a second feature, it may be that the first feature is directly above or obliquely above the second feature, or it may simply mean that the first feature is higher in level than the second feature. When a first feature is “below”, “below” or “below” a second feature, it may be that the first feature is directly below or obliquely below the second feature, or it may simply mean that the first feature is lower in level than the second feature.

[0077] In the description of this specification, the description of the terms "one embodiment", "some embodiments", "embodiment", "example", "specific example" or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0078] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may alter, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A method for preparing niobium aluminum alloy by molten salt electrolysis of cerium niobium perovskite, characterized in that: include: Step 1: Place the raw aluminum at the bottom of the electrolytic cell; Step 2: Mix the raw ore and molten salt in a mass ratio of (1-10):100 and place them in the electrolytic cell; Step 3: heating the bottom of the electrolytic cell to a first preset temperature and then maintaining the temperature for a first preset time to melt the raw aluminum into liquid aluminum; Step 4: After the insulation is completed, the temperature at the bottom of the electrolytic cell is raised to a second preset temperature, the liquid aluminum is used as the cathode, the graphite rod is used as the anode, and after connecting a DC power supply, constant voltage electrolysis is performed according to a preset power supply voltage to obtain an electrolysis product; Step 5: Crushing and grinding the obtained electrolytic products to obtain niobium aluminum alloy and residual molten salt.

2. The method for preparing niobium aluminum alloy by molten salt electrolysis of cerium niobium perovskite according to claim 1, characterized in that: In step 4, the preset power supply voltage is lower than the decomposition voltage of the molten salt system, rare earth and titanium oxides, and higher than the decomposition voltage of niobium oxides.

3. The method for preparing niobium aluminum alloy by molten salt electrolysis of cerium niobium perovskite according to claim 1, characterized in that: In step 2, the molten salt is a mixture of Na3AlF6 and at least one of NaF, LiF or KF.

4. The method for preparing niobium aluminum alloy by molten salt electrolysis of cerium niobium perovskite according to claim 3, characterized in that: In the molten salt, the mass ratio of Na3AlF6 to at least one of NaF, LiF or KF is (7:3)-(5:5).

5. The method for preparing niobium aluminum alloy by molten salt electrolysis of cerium niobium perovskite according to claim 2, characterized in that: The preset power supply voltage is 2-5V.

6. The method for preparing niobium aluminum alloy by molten salt electrolysis of cerium niobium perovskite according to claim 1, characterized in that: In step 2, based on the sum of the mass percentages being 100%, the composition of the raw ore includes: REO is 38%-46%, Nb2O5 is 13%-17%, TiO is 29%-37%, and the remainder is unavoidable impurities.

7. The method for preparing niobium aluminum alloy by molten salt electrolysis of cerium niobium perovskite according to claim 1, characterized in that: In step 3, a preset flow rate of inert gas is introduced for atmosphere protection.

8. The method for preparing niobium aluminum alloy by molten salt electrolysis of cerium niobium perovskite according to claim 1, characterized in that: In step 4, the constant voltage electrolysis is performed for a second preset time, which is 1-5 hours.

9. The method for preparing niobium aluminum alloy by molten salt electrolysis of cerium niobium perovskite according to claim 1, characterized in that: In step 5, after the electrolysis is completed, the cathode, anode and molten salt are cooled under the protection of an inert gas.

10. The method for preparing niobium aluminum alloy by molten salt electrolysis of cerium niobium perovskite according to claim 1, characterized in that: In step 5, the residual molten salt contains rare earth and titanium, which are used for separation and extraction of rare earth and titanium.

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