Separation method of titanium alloy material deoxidation product

Abstract

The invention relates to a separation method of a titanium alloy material deoxidation product. According to the method, magnesium heat or titanium heat deoxidation products of titanium or titanium alloy are used as raw materials, and recovery of fused salt materials, excessive reducing agents and organic solvents is achieved through reasonable solvent extraction, settling separation and organic coating methods; the magnesium oxide or calcium oxide by-product obtained by the method is high in purity and relatively high in value. According to the technological process, no solid waste or waste water or waste gas is generated, it is avoided that extra oxygen is introduced in water washing and acid pickling, and the novel process for treating the titanium alloy deoxidation material is simple, controllable, environmentally friendly and green, and large-scale industrial application is facilitated.

Description

Technical Field

[0001] This invention relates to a method for separating deoxidation products of titanium alloy materials, belonging to the field of metal powder preparation technology. Background Technology

[0002] Titanium and titanium alloys are widely used in aerospace, marine, and biomedical fields due to their low density, high specific strength, corrosion resistance, wear resistance, and non-magnetic properties, making them an important metallic material. In recent years, deoxidation reduction technology for titanium alloy powders has developed rapidly. Currently, it is typically prepared using calcithermal or magnesothermal reduction methods, with the following chemical reaction formula:

[0003] Ti(O)x + xCa = Ti + xCaO

[0004] Ti(O)x + xMg = Ti + xMgO

[0005] The reducing agent is usually an active metal such as Ca or Mg, and a reducing aid, such as halogen salts like MgCl2 or CaCl2, is added. For example, CN03820070.8 describes a deoxidation method for titanium materials, which uses a melt of alkali metal and / or alkaline earth metal salts to dissolve metallic calcium and bring it into contact with the titanium material to achieve deoxidation.

[0006] However, the patent does not describe how to handle excess reducing agent, oxides, and halide salts that did not participate in the reaction. Patent CN115485403A discloses a method for producing particulate titanium alloy products, which includes: preparing a composite particulate oxide mixture comprising titanium oxide powder and at least one alloying element powder, wherein the at least one alloying element powder is at least one of metal oxide powder, elemental metal, and metal hydride, which can deoxidize the heat-treated hydrogenated titanium product to reduce residual oxygen to less than 0.3 wt%.

[0007] In practical applications using solid reducing agents, the products after the reduction reaction typically contain titanium powder, excess reducing agent that did not participate in the reaction, oxides, and halide salts. The separation of titanium powder is currently usually achieved through wet acid leaching, where halide salts are dissolved in water, followed by the addition of acid to dissolve oxides and excess reducing agent, thus obtaining titanium powder. This method consumes large amounts of acid and generates significant amounts of saline wastewater, leading to substantial resource waste. It also increases the risk of oxygen introduction during the washing process and raises the production cost of titanium powder.

[0008] This invention addresses the problems of existing methods for preparing ultra-low oxygen content titanium-based powders using solid reducing agents. It proposes a method based on the principle of halogen salts dissolving in organic solvents, which completely separates titanium-containing materials while simultaneously recovering metal oxides and anhydrous halogen salts. This method avoids the high-cost and high-pollution traditional wet processes, is safe and simple, environmentally friendly, and has significant cost advantages. Furthermore, this invention achieves excellent deoxidation results, realizing for the first time highly efficient and deep deoxidation of small-particle titanium alloys with high surface activity. Summary of the Invention

[0009] The present invention aims to provide a low-cost, low-pollution, and recyclable wet separation process for deoxidation products of titanium alloy materials containing anhydrous halide salts.

[0010] This invention discloses a method for separating deoxidation products from titanium alloy materials, comprising the following process steps:

[0011] (1) Crushing: The deoxidized titanium alloy material is initially crushed until the particle size is less than 1 mm to obtain spare particles; the deoxidized titanium alloy material includes titanium alloy material deoxidized by solid reducing agent and halide.

[0012] (2) Alcohol washing: Add alcohol to the spare particles obtained in step (1) to dissolve; stir, let stand, separate, and then repeat the operation of adding alcohol to dissolve, stirring, letting stand, and separating on the separated solid. Repeat the operation of adding alcohol to dissolve, stirring, letting stand, and separating at least twice; to obtain the lower precipitate and the upper liquid.

[0013] (3) Prepare a 0.8~1.2wt% PMMA THF (tetrahydrofuran) solution, and then add the prepared solution dropwise to the lower precipitate solid obtained in step (2) until it exceeds the upper surface of the precipitate solid in the container. Stir evenly with a stirring rod, and then place it in a vacuum oven to dry at 140~160℃.

[0014] (4) Add the dried sample to anhydrous alcohol, stir at 300~450 rpm and sonicate at 30~60 kHz; after stirring and sonicating for 10~60 min, let stand and the liquid separate into layers; filter, take the solid and dry it below 200℃, and sieve the dried powder through a 250 mesh screen. The sieved powder is PMMA-coated titanium alloy powder with a particle size <60 μm. The anhydrous alcohol includes methanol.

[0015] (4) Removal of PMMA

[0016] The obtained PMMA-coated titanium alloy powder is heat-treated at 395-405℃ for 10-60 minutes to decompose and release PMMA, ultimately yielding a low-oxygen titanium alloy product.

[0017] In industrial applications, it is essential to avoid introducing impurities such as iron during crushing.

[0018] In industrial applications, step (1) can be performed as follows: the deoxidized titanium alloy material is initially crushed until the particle size is less than 1 mm to obtain spare particles; the deoxidized titanium alloy material includes titanium alloy material deoxidized by using solid reducing agent and halide.

[0019] When using solid reducing agents and halides to deoxidize titanium alloy materials, the process includes:

[0020] Anhydrous halide salts in flake or powder form with a purity of 99% or higher and a diameter of <1mm are selected as flux, and coarse-particle reducing metals with a purity of 99.9% or higher and a diameter of <3mm are selected as reducing agents. The titanium alloy material is obtained by wet grinding, granulation, and degreasing of recycled material. The reducing metal is added at 1.5 to 10 times the initial oxygen content of the titanium alloy powder according to its oxygen content molar number. The flux is added at 0.1 to 1 times the sum of the mass of the titanium alloy powder and the reducing metal. The mixture is then heat-treated at 700 to 1000℃ for 60 to 600 minutes.

[0021] After initial crushing, the oxygen content of the deoxidized titanium alloy material can reach up to 10 wt%.

[0022] In this invention, one or more of the anhydrous halides MgCl2, CaCl2, LiCl, and NaCl are used.

[0023] In this invention, the solid reducing agent is selected from at least one of magnesium and calcium.

[0024] In this invention, during alcohol immersion, the alcohol is added using a stirrer, depending on the type of fluxing salt and the solubility of the alcohol. The amount of alcohol added should be at least 1.2 times the solubility of the halogen salt at room temperature, such as 1.5 to 1.8 times. After stirring at 300 to 400 rpm for at least 10 minutes, the mixture is allowed to stand, and the suspension is separated from the lower precipitate.

[0025] In industrial applications, to ensure complete removal of halide salts, the alcohol immersion step is repeated at least twice to ensure the supernatant is clear. If the supernatant is still not clear after three alcohol immersions, the number of immersions can be increased.

[0026] In industrial applications, when the reducing agent is metallic magnesium and the co-solvent is magnesium halide, an appropriate amount of ethanol is used for immersion in alcohols. After coating with PMMA and drying, it is cleaned with an appropriate amount of methanol, and mechanical stirring and ultrasound are used to achieve the dissociation of particulate matter and deep removal of magnesium halide, while also allowing for simple control of the PMMA coating amount.

[0027] This invention uses a 0.8~1.2wt% PMMA THF (tetrahydrofuran) solution for coating. The purpose is to prevent contamination of the titanium alloy product by atmospheric oxygen during high-frequency ultrasonic treatment to separate the metal oxide and titanium alloy products. PMMA is insoluble in alcohols, so when the coated powder is placed in an alcohol solution for ultrasonic treatment, the alcohol will not dissolve the PMMA on the powder surface. If the PMMA concentration in the THF solution is too high, the removal of the final titanium alloy powder product will require a longer heat treatment time. Excessive heat treatment time can easily cause resintering of the titanium alloy powder, or insufficient heat treatment time can lead to PMMA residue, resulting in an increase in the carbon content of the product. Conversely, if the PMMA concentration is too low, insufficient PMMA coating on the powder surface will result in weak oxidation resistance.

[0028] The amount of PMMA-added THF solution in this invention is based on a solution-to-precipitate volume ratio of 1:1 to 0.1. The purpose is to ensure that all powder particles are fully wetted and dispersed, allowing sufficient PMMA to cover the surface of all powder particles, and guaranteeing the efficiency and processability of post-processing. While a high solution volume can fully disperse and wet the powder, it also increases the difficulty and cost of subsequent THF recovery; too low a solution volume is detrimental to slurry mixing, making it difficult for PMMA to uniformly coat the surface of all powder particles.

[0029] Prepare a 0.8~1.2wt% PMMA THF solution, and then add the prepared solution dropwise to the lower precipitate obtained in step (2) until it exceeds the upper surface of the precipitate in the container; the volume ratio of the prepared solution to the lower precipitate is 1:1~0.1.

[0030] In this invention, after coating PMMA and drying it, the dried sample is added to methanol at a volume ratio of 1:1.5~5. The mixture is then stirred at 300~400 rpm and sonicated at 30~50 kHz at 30~50°C. After 25~35 minutes of stirring and sonication, the mixture is allowed to stand. In this step, the amount of methanol should be controlled to be more than 1.5 times the volume of the dried sample to ensure sufficient contact between the powder and methanol. Stirring helps separate metal oxides adhering to the powder and dissolves halogen salts in the methanol.

[0031] The product obtained by this invention has excellent sphericity, low oxygen content, and no cubic crystal precipitation on the powder surface. The product's D90 is less than 50 micrometers. This invention is the first to achieve the effect of a product with an oxygen content of less than 0.125 wt% while having a D90 of less than 50 micrometers.

[0032] Principles and advantages

[0033] This invention is based on the principle that halogen salts have a certain solubility in alcohols, the principle of anhydrous removal of halogen salts from deoxidation products, and the principle that PMMA coating is poorly soluble in alcohols and has a certain antioxidant capacity for metal powders. First, the titanium alloy deoxidation products are crushed into fine particles, then added to alcohols to dissolve the fluxing halogen salts. Under stirring, the halogen salts and oxides are initially separated from the titanium alloy and excess reducing agent metal. Then, through PMMA coating, and under the action of ultrasound and alcohol washing, the halogen salts and oxides are completely separated from the titanium alloy and excess reducing agent metal. The halogen salts are recovered by evaporation crystallization, and the titanium alloy product and excess metal reducing agent are separated by sieving. Finally, the PMMA coating is removed by heat treatment to obtain a low-oxygen titanium alloy product.

[0034] The advantages of this invention are: using alcohols as solvents to separate and recover titanium alloys, halogen salts, oxides, and reducing agent metals, avoiding the use of excessive acids and direct reaction between water and the reducing metals, thus reducing production costs and the discharge of waste liquid and solid waste. Furthermore, using PMMA as an antioxidant coating agent prevents the titanium alloy from directly contacting oxygen in the air during ultrasonication and sieving, reducing the possibility of oxygen pollution. Attached Figure Description

[0035] The present invention will be further illustrated below with reference to the accompanying drawings and examples, but the content of the present invention is not limited thereto.

[0036] Figure 1 A roadmap for existing wet separation methods using water for titanium alloy deoxidation products;

[0037] Figure 2 This is a process flow diagram of the wet separation method for titanium alloy deoxidation products of the present invention;

[0038] Figure 3 Here is a SEM image of the titanium alloy powder product obtained in Example 1;

[0039] Figure 4 Here is a SEM image of the titanium alloy powder product obtained in Example 2;

[0040] Figure 5 Here is a SEM image of the titanium alloy powder product obtained in Comparative Example 1;

[0041] Figure 6 The image shows the SEM image of the titanium alloy powder product obtained in Comparative Example 3. Detailed Implementation

[0042] This invention provides a detailed description of its implementation methods using examples of titanium powder production:

[0043] Example 1

[0044] Five kilograms of deoxidized titanium alloy material (oxygen content 2.58 wt%) were weighed. The deoxidation process used <1 mm flake magnesium chloride and <3 mm coarse-grained magnesium as flux and reducing agent. The titanium alloy material was obtained from recycled material through wet film processing, granulation, and degreasing. The powder, flux, and reducing agent were mixed in a 2:1:1 mass ratio and deoxidized at 800℃ to obtain heat-treated lumps. The target product was 0-60 micrometer spherical titanium alloy powder. The deoxidized product lumps were ground into <1 mm particles in a stainless steel mortar. In these coarse particles, excess reduced magnesium metal existed as irregular particles, and the spherical titanium alloy products were bridged together (the oxygen content in the crushed coarse particles was 0.1011 wt%). 19 liters of anhydrous ethanol was added in three batches at 40℃ to dissolve the coarsely ground deoxidized product particles. Stirring at 360 rpm was applied simultaneously with the addition of anhydrous ethanol. After stirring for 30 minutes, the mixture was allowed to stand for 30 minutes to obtain a suspension. The suspension was separated, yielding a lower precipitate of titanium alloy and excess reduced magnesium metal, as well as a magnesium chloride ethanol solution and suspended white magnesium oxide particles. The lower solid precipitate of titanium alloy contained a small amount of magnesium oxide that could not be separated by simple stirring, and a very small amount of undissolved magnesium chloride.

[0045] The separated suspension was filtered three times, and the white magnesium oxide particles were recovered. The resulting blue-gray magnesium chloride ethanol solution was evaporated and crystallized at 80°C to obtain the evaporated and recovered ethanol and the precipitated crystals. The precipitated crystals were washed three times with 500 mL of anhydrous ethanol to obtain anhydrous magnesium chloride crystals with a purity of 99%.

[0046] For the separated lower precipitate solid, first prepare a 1% PMMA THF (tetrahydrofuran) solution to obtain solution A, then add solution A dropwise to the lower precipitate solid until the liquid surface completely covers the lower precipitate solid (at this time, the volume ratio of solution A to the lower precipitate solid is 1:2). After stirring evenly with a stirring rod, place it in a vacuum oven at 150°C for 1 hour to dry.

[0047] 1.5 kg of dried sample was placed in 1500 mL of anhydrous methanol and subjected to stirring at 360 rpm and sonication at 40 kHz at 40 °C. After 30 min of stirring and sonication, the mixture was allowed to stand for 10 min, resulting in liquid separation. The separated liquids were separated, and the upper suspension was filtered three times to collect the white magnesium oxide particles. The resulting bluish-gray magnesium chloride methanol solution was evaporated and crystallized at 80 °C to obtain precipitated crystals. The precipitated crystals were washed three times with 500 mL of anhydrous methanol to obtain anhydrous magnesium chloride crystals with a purity of 99%.

[0048] The lower precipitate consists of PMMA-coated titanium alloy and PMMA-coated metal reducing agent. The titanium alloy product undergoes multiple dissolution, alcohol washing, and ultrasonic treatment, disrupting the interparticle bridging formed during heat treatment and separating into spherical particles with a diameter less than 60 micrometers. The reduced magnesium metal retains an irregular coarse particle morphology of <1 mm. The PMMA-coated solid is dried in a vacuum oven at 150°C for 30 minutes. The dried powder is then sieved through a 250-mesh sieve. The sieved powder is PMMA-coated titanium alloy powder with a particle size <60 μm, while the unsieved particles are PMMA-coated magnesium particles, which can be used in the deoxidation and reduction step after heat treatment to remove the PMMA.

[0049] The obtained PMMA-coated titanium alloy powder was heat-treated at 400℃ to decompose and release PMMA, ultimately yielding a low-oxygen titanium alloy product.

[0050] The obtained titanium alloy powder product was characterized by SEM, as follows: Figure 3 As shown, the titanium alloy product has good sphericity, and there are no cubic crystal precipitations on the powder surface.

[0051] The oxygen content of the obtained titanium alloy powder product was analyzed and found to be 0.1103 wt%.

[0052] Laser particle size analysis was performed on the obtained titanium alloy powder product, and the D90 was 41.10 micrometers.

[0053] Example 2

[0054] 20 kg of deoxidized titanium alloy material (oxygen content 2.58 wt%) was weighed. The deoxidation process used <1 mm flake magnesium chloride and <3 mm coarse-grained magnesium as flux and reducing agent. The titanium alloy material was obtained from recycled material through wet film processing, granulation, and degreasing. The powder, flux, and reducing agent were mixed in a 2:1:1 mass ratio and deoxidized at 800℃ to obtain heat-treated lumps. The target product was 0-60 micrometer spherical titanium alloy powder. The deoxidized product lumps were ground to <5 mm coarse particles using a jaw crusher. Then, they were crushed and ground to <0.1 mm particles (oxygen content 0.1107 wt%) using a disc crusher. 40 liters of anhydrous methanol was added in 5 batches at 40℃ to dissolve the coarsely ground deoxidized product particles. Stirring at 360 rpm was applied simultaneously with the addition of anhydrous methanol. After 60 minutes of stirring, the mixture was allowed to stand for 60 minutes to obtain a suspension. The suspension was separated to obtain a lower precipitate consisting of titanium alloy and excess reduced magnesium metal, as well as a magnesium chloride methanol solution and suspended white magnesium oxide particles.

[0055] The separated suspension was filtered three times, and the white magnesium oxide particles were recovered. The resulting bluish-gray magnesium chloride methanol solution was evaporated and crystallized at 80°C to obtain the evaporated and recovered methanol and the precipitated crystals. The precipitated crystals were washed three times with 1500 mL of anhydrous methanol to obtain anhydrous magnesium chloride crystals with a purity of 99%.

[0056] For the lower precipitate solid after separation, first prepare a 1% PMMA THF solution, add it dropwise to the lower precipitate solid until it covers the liquid surface, stir evenly with a stirring rod, and then place it in a vacuum oven at 150°C for 1 hour to dry.

[0057] The dried sample was placed in 1500 mL of anhydrous methanol and subjected to stirring at 360 rpm and sonication at 40 kHz at 40 °C. After 50 min of stirring and sonication, the sample was allowed to stand for 30 min, resulting in liquid separation.

[0058] The liquids were separated into two layers. The upper suspension was filtered three times to collect the white magnesium oxide particles. The resulting bluish-gray magnesium chloride methanol solution was evaporated and crystallized at 80°C to obtain precipitated crystals. The precipitated crystals were washed three times with 1500 mL of anhydrous methanol to obtain anhydrous magnesium chloride crystals with a purity of 99%.

[0059] The solid precipitated at the bottom is PMMA-coated titanium alloy product and PMMA-coated metal reducing agent. It is dried in a vacuum oven at 150°C for 30 minutes. The dried powder is sieved through a 250-mesh sieve. The sieved powder is PMMA-coated titanium alloy powder with a particle size of <60μm. The unsieved particles are PMMA-coated magnesium particles. They can be heat-treated to remove PMMA and then used in the deoxidation and reduction step.

[0060] The obtained PMMA-coated titanium alloy powder was heat-treated at 400℃ to decompose and release PMMA, ultimately yielding a low-oxygen titanium alloy product.

[0061] The obtained titanium alloy powder product was characterized by SEM, as follows: Figure 4 As shown, the titanium alloy product has good sphericity, and there are no cubic crystal precipitations on the powder surface.

[0062] The oxygen content of the obtained titanium alloy powder product was analyzed and found to be 0.1204%.

[0063] Laser particle size analysis was performed on the obtained titanium alloy powder product, and the D90 was 47.64 micrometers.

[0064] Example 3:

[0065] The process route used in this embodiment is the same as that in Example 1, except that the 1% PMMA-THF solution is replaced with 1.2% PMMA-THF, while the other parameters remain unchanged.

[0066] The oxygen content of the obtained titanium alloy powder product was analyzed and found to be 0.1098%.

[0067] Laser particle size analysis was performed on the obtained titanium alloy powder product, and the D90 was 42.85 micrometers.

[0068] Example 4:

[0069] The process route used in this embodiment is the same as that in Example 1, except that the 1% PMMA-THF solution is replaced with 0.8% PMMA-THF, while the other parameters remain unchanged.

[0070] The oxygen content of the obtained titanium alloy powder product was analyzed and found to be 0.1155%.

[0071] Laser particle size analysis was performed on the obtained titanium alloy powder product, and the D90 was 43.00 micrometers.

[0072] Comparative Example 1:

[0073] Weigh 1 kg of deoxidized titanium alloy material (raw material composition is the same as in Example 2). The deoxidation process uses magnesium chloride and magnesium as flux and reducing agent (the flux and reducing agent and reduction conditions are the same as in Example 2). Grind the deoxidized product lumps to <0.1 mm particles using a jaw crusher. Take 20 liters of deionized water and add it to the coarsely ground deoxidized product particles in three batches at 40°C to dissolve them. While adding the deionized water, stir at 360 rpm. After stirring for 60 minutes, let stand for 60 minutes to obtain a suspension. Separate the suspension to obtain a lower precipitate of titanium alloy and a small amount of excess reduced magnesium metal, as well as an aqueous solution of magnesium chloride and suspended white magnesium oxide particles.

[0074] The separated suspension was filtered three times to remove and recover the white magnesium oxide particles. The resulting gray magnesium chloride aqueous alcohol solution was evaporated and crystallized at 80°C to obtain magnesium chloride crystals containing water of crystallization.

[0075] Add 37% concentrated hydrochloric acid to the lower precipitate solid after separation, while stirring at 360 rpm. Keep the pH at 2.5 and let stand for 30 minutes to allow the liquid to separate into layers.

[0076] The suspension was separated, and the upper suspension was filtered three times to remove white magnesium oxide particles for recovery. The resulting gray magnesium chloride aqueous solution was evaporated and crystallized at 80°C to obtain magnesium chloride crystals containing water of crystallization.

[0077] The solids in the lower layer are placed in a vacuum oven and dried at 80°C for 30 minutes. The dried powder is then sieved through a 250-mesh sieve to produce low-oxygen spherical titanium alloy products.

[0078] The obtained titanium alloy powder product was characterized by SEM, as follows: Figure 5 As shown, the titanium alloy product has good sphericity, and there are no cubic crystal precipitations on the powder surface.

[0079] The oxygen content of the obtained titanium alloy powder product was analyzed and found to be 0.3232%.

[0080] Laser particle size analysis was performed on the obtained titanium alloy powder product, and the D90 was 51.62 micrometers.

[0081] Comparative Example 2:

[0082] The process route used in this comparative example is the same as that of comparative example 1, except that 37% concentrated hydrochloric acid was replaced with 30% acetic acid, while the other parameters remained unchanged. The obtained titanium alloy powder product was characterized by SEM. The titanium alloy product had good sphericity and no cubic crystals precipitated on the powder surface.

[0083] The oxygen content of the obtained titanium alloy powder product was analyzed and found to be 0.6301%.

[0084] Laser particle size analysis was performed on the obtained titanium alloy powder product, and the D90 was 52.18 micrometers.

[0085] Comparative Example 3:

[0086] Five kilograms of deoxidized titanium alloy material (composition consistent with Example 2) were weighed. The deoxidation process used magnesium chloride and magnesium as flux and reducing agent (the flux, reducing agent, and reduction conditions were consistent with Example 2). The deoxidized product lumps were ground into <1 mm particles in a stainless steel mortar. 19 liters of anhydrous ethanol was added in three batches at 40°C to dissolve the coarsely ground deoxidized product particles. Simultaneously with the addition of anhydrous ethanol, stirring was applied at 360 rpm. After stirring for 30 minutes, the mixture was allowed to stand for 30 minutes to obtain a suspension. The suspension was separated, yielding a lower precipitate of titanium alloy and excess reduced magnesium metal, as well as a magnesium chloride ethanol solution and suspended white magnesium oxide particles.

[0087] The separated suspension was filtered three times, and the white magnesium oxide particles were recovered. The resulting blue-gray magnesium chloride ethanol solution was evaporated and crystallized at 80°C to obtain the evaporated and recovered ethanol and the precipitated crystals. The precipitated crystals were washed three times with 500 mL of anhydrous ethanol to obtain anhydrous magnesium chloride crystals.

[0088] The lower precipitate solid after separation was placed in 1500 mL of anhydrous methanol and stirred at 360 rpm at 40 °C. After stirring for 30 min and standing for 10 min, the liquid separated into layers.

[0089] The liquids were separated into two layers. The upper suspension was filtered three times to collect the white magnesium oxide particles. The resulting blue-gray magnesium chloride methanol solution was evaporated and crystallized at 80°C to obtain precipitated crystals. The precipitated crystals were washed three times with 500 mL of anhydrous methanol to obtain anhydrous magnesium chloride crystals.

[0090] The solids in the lower layer were placed in a vacuum oven and dried at 150°C for 30 minutes. The dried powder was then sieved through a 250-mesh sieve, and the sieved powder was titanium alloy powder with a particle size of <60μm.

[0091] The obtained titanium alloy powder product was characterized by SEM, as follows: Figure 6 As shown, the titanium alloy product has good sphericity, and there are crystal precipitations on the powder surface. EDS shows the presence of magnesium, oxygen, and chlorine elements on the surface. Among them, the enrichment positions of oxygen and chlorine elements on the powder surface are basically consistent with the positions of magnesium elements, indicating the presence of a large amount of MgO and MgCl2 on the powder surface.

[0092] The oxygen content of the obtained titanium alloy powder product was analyzed and found to be 0.8531%.

[0093] Laser particle size analysis was performed on the obtained titanium alloy powder product, and the D90 was 46.52 micrometers.

[0094] Comparative Example 4:

[0095] Five kilograms of deoxidized titanium alloy material (composition consistent with Example 2) were weighed. The deoxidation process used magnesium chloride and magnesium as flux and reducing agent (the flux, reducing agent, and reduction conditions were consistent with Example 2). The deoxidized product lumps were ground into <1 mm particles in a stainless steel mortar. 19 liters of anhydrous ethanol was added in three batches at 40°C to dissolve the coarsely ground deoxidized product particles. Simultaneously with the addition of anhydrous ethanol, stirring was applied at 360 rpm. After stirring for 30 minutes, the mixture was allowed to stand for 30 minutes to obtain a suspension. The suspension was separated, yielding a lower precipitate of titanium alloy and excess reduced magnesium metal, as well as a magnesium chloride ethanol solution and suspended white magnesium oxide particles.

[0096] The separated suspension was filtered three times, and the white magnesium oxide particles were recovered. The resulting blue-gray magnesium chloride ethanol solution was evaporated and crystallized at 80°C to obtain the evaporated and recovered ethanol and the precipitated crystals. The precipitated crystals were washed three times with 500 mL of anhydrous ethanol to obtain anhydrous magnesium chloride crystals.

[0097] The lower precipitate solid after separation was placed in 1500 mL of anhydrous methanol and subjected to stirring at 360 rpm and sonication at 40 kHz at 40 °C. After stirring for 30 min and standing for 10 min, the liquids separated into layers.

[0098] The liquids were separated into two layers. The upper suspension was filtered three times to collect the white magnesium oxide particles. The resulting blue-gray magnesium chloride methanol solution was evaporated and crystallized at 80°C to obtain precipitated crystals. The precipitated crystals were washed three times with 500 mL of anhydrous methanol to obtain anhydrous magnesium chloride crystals.

[0099] The solids in the lower layer were placed in a vacuum oven and dried at 150°C for 30 minutes. The dried powder was then sieved through a 250-mesh sieve, and the sieved powder was titanium alloy powder with a particle size of <60μm.

[0100] The obtained titanium alloy powder product was characterized by SEM. The titanium alloy product had good sphericity, and there were crystal precipitations on the powder surface. EDS showed the presence of magnesium and oxygen elements on the surface. In particular, the oxygen enrichment positions on the powder surface were basically consistent with the magnesium enrichment positions, indicating the presence of a large amount of MgO on the powder surface.

[0101] The oxygen content of the obtained titanium alloy powder product was analyzed and found to be 0.4585%.

[0102] Laser particle size analysis was performed on the obtained titanium alloy powder product, and the D90 was 47.66 micrometers.

[0103] Comparative Example 5:

[0104] Five kilograms of deoxidized titanium alloy material (composition consistent with Example 2) were weighed. The deoxidation process used magnesium chloride and magnesium as flux and reducing agent (the flux, reducing agent, and reduction conditions were consistent with Example 2). The deoxidized product lumps were ground into <1 mm particles in a stainless steel mortar. 19 liters of anhydrous ethanol was added in three batches at 40°C to dissolve the coarsely ground deoxidized product particles. Simultaneously with the addition of anhydrous ethanol, stirring was applied at 360 rpm. After stirring for 30 minutes, the mixture was allowed to stand for 30 minutes to obtain a suspension. The suspension was separated, yielding a lower precipitate of titanium alloy and excess reduced magnesium metal, as well as a magnesium chloride ethanol solution and suspended white magnesium oxide particles.

[0105] The separated suspension was filtered three times, and the white magnesium oxide particles were recovered. The resulting blue-gray magnesium chloride ethanol solution was evaporated and crystallized at 80°C to obtain the evaporated and recovered ethanol and the precipitated crystals. The precipitated crystals were washed three times with 500 mL of anhydrous ethanol to obtain anhydrous magnesium chloride crystals.

[0106] The solids in the lower layer were placed in a vacuum oven and dried at 150°C for 30 minutes. The dried powder was then sieved through a 250-mesh sieve, and the sieved powder was titanium alloy powder with a particle size of <60μm.

[0107] The obtained titanium alloy powder product was characterized by SEM. The titanium alloy product had good sphericity, and there were crystal precipitations on the powder surface. EDS showed that magnesium, oxygen, and chlorine elements were present on the surface. Among them, the enrichment positions of oxygen and chlorine elements on the powder surface were basically consistent with the positions of magnesium elements, indicating that there were a large amount of MgO and MgCl2 on the powder surface.

[0108] The oxygen content of the obtained titanium alloy powder product was analyzed and found to be 1.7516%.

[0109] Laser particle size analysis was performed on the obtained titanium alloy powder product, and the D90 was 45.26 micrometers.

[0110] Comparative Example 6:

[0111] The process route used in this embodiment is the same as that in Example 1, except that the 1% PMMA-THF solution is replaced with 0.1% PMMA-THF, while the other parameters remain unchanged.

[0112] The oxygen content of the obtained titanium alloy powder product was analyzed and found to be 0.7130%.

[0113] Laser particle size analysis was performed on the obtained titanium alloy powder product, and the D90 was 48.87 micrometers.

[0114] .

Claims

1. A method for separating deoxidation products of titanium alloy materials, characterized in that, It includes the following process steps: (1) Crushing: The deoxidized titanium alloy material is initially crushed until the particle size is less than 1 mm to obtain spare particles; the deoxidized titanium alloy material includes titanium alloy material deoxidized by solid reducing agent and halide. (2) Alcohol washing: Add alcohol to the spare particles obtained in step (1) to dissolve; stir, let stand, separate, and then repeat the operation of adding alcohol to dissolve, stirring, letting stand, and separating on the separated solid. Repeat the operation of adding alcohol to dissolve, stirring, letting stand, and separating at least twice; to obtain the lower precipitate and the upper liquid. (3) Prepare a 0.8~1.2wt% PMMA THF solution, and then add the prepared solution dropwise to the lower precipitate solid obtained in step (2) until it exceeds the upper surface of the precipitate solid in the container. Stir evenly with a stirring rod, and then place it in a vacuum oven to dry at 140~160℃. The dried sample was added to anhydrous alcohol and stirred at 300-450 rpm and sonicated at 30-60 kHz. After stirring and sonicating for 10-60 minutes, let stand and the liquid will separate into layers. Filter the solid, dry it at a temperature below 200°C, and then sieve the dried powder through a 250-mesh sieve. The sieved powder is PMMA-coated titanium alloy powder with a particle size of <60μm. The anhydrous alcohols include methanol. (4) Removal of PMMA The obtained PMMA-coated titanium alloy powder is heat-treated at 390-405℃ for 10-60 minutes to decompose and release PMMA, ultimately yielding a low-oxygen titanium alloy product.

2. The method for separating deoxidation products of titanium alloy materials according to claim 1, characterized in that: Anhydrous halide salts in flake or powder form with a purity of 99% or higher and a diameter of <1mm are selected as fluxes, and coarse-particle reducing metals with a purity of 99.9% or higher and a diameter of <3mm are selected as reducing agents. The titanium alloy material is obtained by wet grinding, granulation, and degreasing of recycled materials. Based on the initial oxygen content of the titanium alloy powder, add reducing metal at a rate of 1.5 to 10 times its oxygen content molars. Add flux at a ratio of 0.1 to 1 times the sum of the mass of titanium alloy powder and reduced metal, and perform heat treatment at 700 to 1000°C for 60 to 600 minutes.

3. The method for separating deoxidation products of titanium alloy materials according to claim 1, characterized in that: One or more of the following anhydrous halides: MgCl2, CaCl2, LiCl, and NaCl; The solid reducing agent is selected from at least one of magnesium and calcium.

4. The method for separating deoxidation products of titanium alloy materials according to claim 1, characterized in that: After initial crushing, the oxygen content of the deoxidized titanium alloy material can reach up to 10 wt%.

5. The method for separating deoxidation products of titanium alloy materials according to claim 1, characterized in that: During alcohol immersion, the amount of alcohol added should be stirred using a stirrer, depending on the type of fluxing salt and the solubility of the alcohol. The amount of alcohol added should be greater than 1.2 of the solubility of the halogen salt at room temperature. During alcohol immersion, the mixture should be stirred at 300-400 rpm for at least 10 minutes, then allowed to stand to separate the suspension from the lower precipitate.

6. The method for separating deoxidation products of titanium alloy materials according to claim 1, characterized in that: The alcohol immersion step is repeated at least twice to make the supernatant clear.

7. The method for separating deoxidation products of titanium alloy materials according to claim 1, characterized in that: When performing a single alcohol immersion, add anhydrous ethanol at a ratio of 3-5 liters per kilogram of spare granules.

8. The method for separating deoxidation products of titanium alloy materials according to claim 1, characterized in that: Prepare a 0.8~1.2wt% PMMA THF solution, and then add the prepared solution dropwise to the lower precipitate obtained in step (2) until it exceeds the upper surface of the precipitate in the container; the volume ratio of the prepared solution to the lower precipitate is 1:1~0.

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9. The method for separating deoxidation products of titanium alloy materials according to claim 1, characterized in that: After coating with PMMA and drying, the dried sample is added to methanol at a volume ratio of 1:1.5~5, and stirred at 300~400 rpm and sonicated at 30~50 kHz at 30~50℃. After stirring and ultrasonic treatment for 25-35 minutes, let it stand.

10. The method for separating deoxidation products of titanium alloy materials according to claim 9, characterized in that: The resulting product has a D90 of less than 50 micrometers and an oxygen content of less than 0.125 wt%.

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