Pure titanium powder and its preparation methods and applications using titanium waste

Abstract

This invention provides a method for preparing pure titanium powder from titanium waste and its applications. In this preparation method, a mixture of calcium hydride and chloride salts is used as the deoxidizer for hydrogenated dehydrogenated titanium powder. Titanium powder is mixed with calcium hydride and calcium / potassium / lithium chloride salts in a specific ratio. The heating process generates hydrogen and elemental calcium to perform dual deoxidation on the titanium powder. Simultaneously, the hydrogen-assisted action significantly reduces the deoxidation temperature range of the titanium powder. This invention achieves the recycling of residual titanium materials to prepare low-oxygen titanium powder, realizing the recycling of titanium materials and possessing broad application prospects.

Description

Technical Field

[0001] This invention relates to the field of titanium powder production and manufacturing technology, specifically to a pure titanium powder and a method and application for preparing it using titanium waste. Background Technology

[0002] Titanium powder is now widely used in key fields such as additive manufacturing, powder metallurgy, and the manufacture of aerospace equipment components. Titanium is a high-value metal due to its superior properties. However, its high reactivity with oxygen results in high production costs. Therefore, industrial production requires reducing the oxygen content in titanium waste, shavings, chips, large pieces, and powders to achieve recycling, reuse, and high-quality powder production. While directly using residual titanium waste generated in industrial production to prepare titanium powder can alleviate the high price of high-quality titanium powder in powder metallurgy and additive manufacturing to some extent, the oxygen content of the prepared titanium powder still does not meet practical requirements.

[0003] The deoxidation of titanium powder with high oxygen content mainly falls into two categories. The first is to remove oxygen from the titanium powder by utilizing the high reactivity of chemically active metals with oxygen. The second method involves adding rare earth elements to the titanium powder, leveraging their solid-solution ability to reduce oxygen content in other areas of the powder. However, both methods suffer from low recovery rates of deoxidized metal powder, low powder purity, and high prices of deoxidizers, limiting their widespread application in industrial production. Summary of the Invention

[0004] To overcome the shortcomings of the prior art, the main objective of this invention is to provide a pure titanium powder, a method for preparing it from titanium waste, and its application. In this preparation method, a mixture of calcium hydride and chloride salt is used as a deoxidizer for hydrogenated dehydrogenated titanium powder. Through interaction with the high-oxygen titanium powder prepared by hydrogenation dehydrogenation, the concentration of dissolved oxygen in the titanium powder and the thickness of the surface oxide film are reduced, thereby achieving the overall deoxidation effect of the high-oxygen titanium powder. Ultimately, this achieves efficient utilization of residual titanium waste, saves a large amount of precious metal resources, and reduces costs.

[0005] To achieve the above objectives, a first aspect of the present invention provides a method for preparing pure titanium powder from titanium waste, comprising the following steps:

[0006] The obtained titanium waste is subjected to hydrogenation and dehydrogenation treatment to obtain hydrogenated and dehydrogenated titanium powder.

[0007] Under a protective atmosphere, the hydrogenated dehydrogenated titanium powder is reacted with a deoxidizing agent to obtain a deoxidized product; wherein the deoxidizing agent is a mixture comprising CaH2 and chloride salts;

[0008] The deoxidation product was washed and dried to obtain pure titanium powder.

[0009] Furthermore, the mass ratio of the deoxidizer to the hydrogenated dehydrogenated titanium powder is (0.15~0.2):1.

[0010] Preferably, the particle size of the deoxidizer is 5-20 mm.

[0011] Furthermore, in the deoxidizing agent, the mass ratio of CaH2 to the chloride salt is 1:(1.5-2.0).

[0012] Preferably, the chloride salt comprises a mixture of any one of KCl and LiCl with CaCl2.

[0013] Furthermore, the mass ratio of CaCl2 to KCl or LiCl is (0.05 to 0.5):1.

[0014] Preferably, the mass ratio of CaH2 to CaCl2 to KCl or LiCl is 1:(0.075-1):(1.5-2.0).

[0015] Furthermore, the deoxygenation reaction is carried out at a temperature of 600–800°C for a time of 0.5–2 hours.

[0016] Preferably, the protective gas in the deoxygenation reaction includes argon.

[0017] Preferably, the heating rate is 10°C / min, and the reaction is cooled to room temperature at 10°C / min after completion.

[0018] Furthermore, the particle size of the hydrogenated dehydrogenated titanium powder is 20–70 μm.

[0019] Preferably, the hydrogenation-dehydrogenation treatment includes sequential hydrogenation, ball milling, and dehydrogenation, wherein: the hydrogenation temperature is 400–700°C, the time is 3–7 h, and the furnace pressure is 0.11–0.15 MPa;

[0020] The ball-to-material ratio for ball mill crushing is 5–10:1, and the rotation speed is 150–300 rpm.

[0021] The dehydrogenation temperature is 400–600℃, and the dehydrogenation time is 1–5 hours.

[0022] Furthermore, the deoxygenation product is subjected to acid washing to remove water-soluble salts and byproduct CaO.

[0023] Preferably, the pickling agent used in the pickling process includes hydrochloric acid.

[0024] Preferably, the drying temperature is 55–120°C and the drying time is 0.5–3 hours.

[0025] Furthermore, before performing the hydrogenation and dehydrogenation treatment, the process further includes: sequentially performing surface treatment, crushing, cleaning, and separation treatment on the titanium waste to remove surface impurities and inclusions from the titanium waste.

[0026] Preferably, the particle size of the titanium waste after crushing is 50-150 μm.

[0027] To achieve the above objectives, a second aspect of the present invention provides a pure titanium powder.

[0028] The pure titanium powder is prepared by the method for preparing pure titanium powder from titanium waste provided in the first aspect of the present invention, wherein the oxygen content of the pure titanium powder is ≤1000ppm.

[0029] To achieve the above objectives, a third aspect of the present invention provides an application of pure titanium powder.

[0030] The pure titanium powder prepared by the method for preparing pure titanium powder from titanium waste provided in the first aspect of the present invention, or the pure titanium powder provided in the second aspect of the present invention, can be used in the manufacturing of devices for aerospace, additive manufacturing, and marine engineering.

[0031] Calcium hydride decomposes at high temperature to produce hydrogen gas and metallic calcium. The generated hydrogen gas is used to promote the reaction of titanium dioxide with calcium chloride (CaCl2) and eutectic salt (KCl or LiCl) for deoxidation, reducing the deoxidation time from 12-24 h to 0.5-2 h. In addition, hydrogen (H2) can destroy the stability of Ti-O solid solution, thereby removing some of the dissolved oxygen. Furthermore, with the help of hydrogen, oxygen diffusion in β-Ti can be accelerated.

[0032] In this invention, calcium hydride is added to a calcium chloride halide molten salt to form a composite molten salt. When the target temperature is reached, it interacts with the high-oxygen titanium powder prepared by hydrogenation dehydrogenation, thereby reducing the oxygen concentration in the solid solution and the thickness of the surface oxide film in the titanium powder, thus achieving the overall deoxidation effect of the high-oxygen titanium powder.

[0033] In this invention, hydrogen gas generated from the in-situ decomposition of calcium hydride and the calcium produced from the decomposition form calcium ions in the molten salt. These calcium ions, along with those from calcium chloride, interact with oxygen ions on the surface of titanium powder to generate calcium oxide, which is more stable than titanium dioxide. The dissolved oxygen in the titanium powder diffuses to the surface, and the oxygen reacts with electrons in the molten salt to generate oxygen ions (O₂). 2- This leaves a low concentration of oxygen on the oxygen-containing surface, and the consumption of electrons drives the reaction Ca→Ca. 2+ +2e - Promote the production of oxygen ions (O) 2- The consumption of oxygen in titanium powder is achieved by removing oxygen from the titanium powder.

[0034] Advantages of this invention:

[0035] 1. In this invention, a mixture of calcium hydride (CaH2) and chloride salt is used as a deoxidizer for hydrogenated dehydrogenated titanium powder. The application of calcium hydride to the deoxidation of titanium powder and titanium products by molten salt is proposed for the first time.

[0036] 2. In this invention, calcium hydride and calcium chloride, along with a certain amount of KCl or LiCl, are used as deoxidizers. Compared to solid calcium, salts such as LiCl or KCl help lower the melting point of the salt and create a low-temperature reaction environment. Low-temperature operating conditions have many advantages, such as less corrosion and thermal damage to the container, more choices of container materials and equipment, continuous reactor production due to the absence of loss of metal deoxidizers such as Ca, easier leaching and crushing, and preservation of the original size and morphology of the particles due to less sintering bonding between particles.

[0037] 3. In this invention, the deoxidation ability of solid calcium on titanium powder is improved by modifying the process. This is achieved by controlling the deoxidation temperature range, holding time, and ambient atmosphere. In particular, the deoxidation atmosphere contains some hydrogen, which is not found in the current patented methods and literature on titanium powder deoxidation.

[0038] 4. The preparation process in this invention can reduce the temperature range for titanium powder deoxidation, allowing the reaction to proceed at around 650°C. This achieves the effect of reducing the temperature range and energy consumption while controlling the oxygen content of the titanium powder to within 1000 ppm.

[0039] 5. This invention enables the recycling of residual titanium materials to prepare low-oxygen titanium powder, achieving the recycling of titanium materials and having broad application prospects.

[0040] 6. Titanium powder obtained from titanium waste can be used for 3D printing and injection molding of precision parts, and is widely used in aerospace, biomedical engineering, and precision instruments. Detailed Implementation

[0041] Exemplary embodiments of this disclosure will now be described in detail. It should be understood that this disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of this disclosure to those skilled in the art.

[0042] Based on the research on efficient utilization of titanium resources and low-cost production processes, this invention proposes a method to reduce the oxygen content in titanium powder by preparing a deoxidizer by mixing calcium hydride and chloride salt in a certain proportion. This process is simple, low-cost, and easy to promote large-scale application, thereby driving the cost reduction of titanium powder.

[0043] This invention introduces calcium hydride into a calcium chloride halide molten salt to form a composite molten salt, which acts as a deoxidizer. At the target temperature, it interacts with the high-oxygen titanium powder prepared by hydrogenation dehydrogenation to reduce the concentration of dissolved oxygen in the titanium powder and the thickness of the surface oxide film, thereby achieving the overall deoxidation effect of the high-oxygen titanium powder.

[0044] The first aspect of this invention provides a method for preparing pure titanium powder using titanium waste.

[0045] The method for preparing pure titanium powder from titanium waste in this invention is carried out according to the following steps.

[0046] (1) Surface treatment of titanium waste

[0047] The recycled titanium waste is cleaned to remove surface dust, impurities, and oil.

[0048] In embodiments of the present invention, the size specifications of titanium waste include: titanium shavings with a thickness ranging from 0.1 mm to 3 mm, a width ranging from 0.5 mm to 50 mm, and a length ranging from 10 mm to 500 mm; granular titanium with a particle size ranging from 0.5 mm to 3 mm; and blocky titanium with a thickness ranging from 3 mm to 10 mm and a width ranging from 2 mm to 100 mm.

[0049] In an embodiment of the present invention, the recycled titanium waste is placed in an ultrasonic cleaning device containing a degreasing agent to remove surface oil and water-soluble impurities.

[0050] In some embodiments of the present invention, titanium waste is placed in an ultrasonic cleaning device, and the titanium waste is immersed in hot water at 50-60°C and stirred for more than 10 minutes to remove water-soluble impurities on the surface; then the hot water is drained, Na2CO3 solution is added to submerge the titanium waste and heated to 60-80°C, and stirred continuously for more than 20 minutes to remove oil; after draining the Na2CO3 solution, room temperature water is added and stirred for more than 5 minutes to clean the residual Na2CO3 solution.

[0051] (2) Crushing, washing and separation of titanium waste

[0052] The surface-treated titanium waste is crushed and ultrasonically cleaned to remove residual impurities. Then, a magnetic separator and centrifuge are used to centrifuge the fully crushed titanium waste to separate the impurities and obtain high-purity titanium chips and / or particles, which can be used as raw materials for hydrogenation dehydrogenation.

[0053] In an embodiment of the present invention, titanium waste is repeatedly crushed and ball-milled using a crusher and a ball mill, wherein the ball milling media are stainless steel balls, and the mass ratio of stainless steel balls to grinding media is always maintained at 20:1, with steel balls of different particle sizes. Ball milling was performed at speeds of 73 rpm, 70 rpm, and 68 rpm respectively to better control the particle size range of the processed titanium waste to 50–150 μm.

[0054] In an embodiment of the present invention, a magnetic separator is used to repeatedly remove magnetic impurities to ensure the purity of the titanium waste.

[0055] (3) Hydrogenation and dehydrogenation treatment

[0056] The separated titanium chips and / or particles are first hydrogenated, then ball-milled and dehydrogenated to obtain hydrogenated and dehydrogenated titanium powder.

[0057] In an embodiment of the present invention, a rotary hydrogenation dehydrogenation furnace is used, with the vacuum level maintained below 0.1 Pa, the pressure rise rate within 10 Pa / min, the furnace gas pressure maintained between 0.11 and 0.15 MPa, the pressure drop less than 10 Pa / min, the hydrogenation temperature between 400 and 700 °C, and the time between 3 and 7 hours.

[0058] After hydrogenation, the material is ball-milled under an argon protective atmosphere with a ball-to-material ratio of 5–10:1 and a rotation speed of 150–300 rpm.

[0059] Subsequently, dehydrogenation was carried out under vacuum conditions, with the dehydrogenation temperature controlled between 400 and 600°C, and the temperature was maintained for 1 to 5 hours.

[0060] The particle size of the powder obtained after hydrogenation and dehydrogenation treatment is in the range of 20 to 70 μm.

[0061] For example, the hydrogenation temperature is one of 400°C, 450°C, 500°C, 550°C, 600°C, 650°C, 700°C or any value that satisfies the above range.

[0062] For example, the gas pressure inside the furnace is one of 0.11 MPa, 0.12 MPa, 0.13 MPa, 0.14 MPa, or 0.15 MPa, or any value that meets the above range.

[0063] For example, the ball-to-powder ratio is one of 5:1, 6:1, 7:1, 8:1, 9:1, 10:1 or any value that satisfies the above range.

[0064] For example, the rotational speed is one of 150 rpm, 160 rpm, 170 rpm, 180 rpm, 190 rpm, 200 rpm, 210 rpm, 220 rpm, 230 rpm, 240 rpm, 250 rpm, 260 rpm, 270 rpm, 280 rpm, 290 rpm, and 300 rpm, or any value that satisfies the above range.

[0065] For example, the dehydrogenation temperature is one of 400°C, 450°C, 500°C, 550°C, 600°C or any value that meets the above range.

[0066] It is worth mentioning that the particle size of the hydrogenated dehydrogenated titanium powder obtained after hydrogenation and dehydrogenation treatment is strictly controlled within the range of 20 to 70 μm.

[0067] For example, the particle size of the hydrogenated dehydrogenated titanium powder is one of 20μm, 30μm, 40μm, 50μm, 60μm, 70μm or any value that meets the above range.

[0068] (4) Deoxygenation treatment

[0069] Under a protective atmosphere, such as an argon atmosphere throughout the process, hydrogenated dehydrogenated titanium powder and deoxidizer are mixed in a certain ratio. The hydrogenated dehydrogenated titanium powder is placed in a stainless steel crucible, and the deoxidizer is placed at the bottom of the inner side of the stainless steel crucible. Then, they are placed together in a tube furnace, and the reaction is carried out at high temperature to achieve the purpose of deoxidation of titanium powder.

[0070] In an embodiment of the present invention, a protective atmosphere is formed by blowing argon gas to prevent oxygen from coming into contact with the atmosphere, and the temperature is increased to the reaction temperature of 600-800°C at a rate of 10°C / min, with a reaction time of 0.5-2 hours; after the reaction is completed, the temperature is cooled to room temperature of 25°C at a rate of 10°C / min.

[0071] Titanium powder is mixed with calcium hydride and calcium / potassium / lithium chloride salts in a certain proportion. The heating process generates hydrogen and elemental calcium to perform dual deoxidation on the titanium powder. At the same time, the temperature range for titanium powder deoxidation is significantly reduced with the assistance of hydrogen.

[0072] For example, the deoxygenation reaction temperature is one of 600°C, 650°C, 700°C, 750°C, 800°C or any value that meets the above range.

[0073] For example, the deoxygenation reaction time is one of 0.5h, 0.8h, 1h, 1.2h, 1.5h, 1.8h, 2h or any value that satisfies the above range.

[0074] In an embodiment of the present invention, the mass ratio of deoxidizer to hydrogenated dehydrogenated titanium powder is (0.15-0.2):1.

[0075] For example, the mass ratio of the deoxidizer to the hydrogenated dehydrogenated titanium powder is one of 0.15:1, 0.16:1, 0.17:1, 0.18:1, 0.19:1, 0.2:1 or any value within the range described above.

[0076] In embodiments of the present invention, the particle size of the deoxidizer is 5-20 mm.

[0077] In embodiments of the present invention, the deoxidizer is a mixture comprising CaH2 and chloride salt.

[0078] In some embodiments of the present invention, the mass ratio of CaH2 to chloride salt is 1:(1.5-2).

[0079] For example, the mass ratio of CaH2 to chloride is one of 1:1.5, 1:1.6, 1:1.7, 1:1.8, 1:1.9, 1:2 or any value within the range mentioned above.

[0080] In embodiments of the present invention, the chloride salt includes a mixture of any one of KCl and LiCl with CaCl2.

[0081] In this invention, the deoxygenation mechanism is that in the calcium chloride halide molten salt with added calcium hydride, at the corresponding temperature, calcium hydride decomposes to produce some hydrogen gas, which converts the stable Ti-O solid solution into the less unstable Ti-OH solid solution, thereby reducing the temperature of the deoxygenation reaction.

[0082] Introducing calcium hydride into calcium chloride halide molten salt allows for the introduction of in-situ generated hydrogen gas and decomposed calcium. Calcium ions form in the molten salt, and these ions interact with oxygen ions on the titanium powder surface to generate calcium oxide, which is more stable than titanium dioxide. Solid dissolved oxygen in the titanium powder diffuses to the surface, reacting with electrons in the molten salt to generate oxygen ions (O₂). 2- This leaves a low concentration of oxygen on the oxygen-containing surface, and the consumption of electrons drives the reaction Ca→Ca. 2+ +2e - Promote the production of oxygen ions (O) 2- The consumption of oxygen in titanium powder is achieved by removing oxygen from the titanium powder.

[0083] Molten salts provide a pathway for the transport of calcium ions and for the contact between calcium ions and oxygen-containing titanium in the reaction, making the contact reaction more efficient.

[0084] In some embodiments of the present invention, the mass ratio of CaCl2 to KCl or LiCl is (0.05 to 0.5):1.

[0085] For example, the mass ratio of CaCl2 to KCl or LiCl is one of the following: 0.05:1, 0.06:1, 0.07:1, 0.08:1, 0.09:1, 0.10:1, 0.11:1, 0.12:1, 0.13:1, 0.14:1, 0.15:1, 0.16:1, 0.17:1, 0.18:1, 0.19:1, 0.20:1, 0.22:1, 0.25:1, 0.28:1, 0.29:1, 0.3:1, 0.32:1, 0.35:1, 0.38:1, 0.4:1, 0.42:1, 0.45:1, 0.48:1, 0.5:1, or any value within the range described above.

[0086] In some embodiments of the present invention, the mass ratio of CaH2:CaCl2:KCl or LiCl is 1:(0.075-1):(1.5-2).

[0087] For example, the mass ratio of CaH2:CaCl2:KCl or LiCl is one of the following: 1:0.075:1.5, 1:0.1:1.5, 1:0.5:1.5, 1:1:1.5, 1:0.075:2, 1:0.1:2, 1:0.5:2, 1:1:2 or any value that satisfies the above range.

[0088] (5) Pickling treatment

[0089] The deoxidized products after complete reaction in the stainless steel crucible are acid-washed to remove surface oxides and water-soluble salts.

[0090] In an embodiment of the present invention, the deoxygenation product is leached with hydrochloric acid solution to remove water-soluble salts and byproduct CaO.

[0091] As some embodiments of the present invention, the water-soluble salts and byproduct CaO are removed by leaching with a 5-15% dilute hydrochloric acid solution for 0.5-2 hours; then the water is washed with ultrapure water.

[0092] (6) Vacuum drying

[0093] The titanium powder obtained after acid washing is dried in a vacuum drying oven to obtain pure titanium powder.

[0094] In an embodiment of the present invention, the acid-washed powder is washed with high-purity water and then dried in a vacuum oven at a temperature of 55–120°C for 0.5–3 hours.

[0095] A second aspect of the present invention provides a pure titanium powder with an oxygen content ≤1000ppm.

[0096] The pure titanium powder provided in the second aspect of the present invention is prepared using the preparation method provided in the first aspect of the present invention.

[0097] The third aspect of this invention provides a specific application of pure titanium powder, such as in the manufacture of aerospace devices, in the manufacture of additive manufacturing devices, and in the manufacture of marine engineering devices.

[0098] The pure titanium powder provided in the third aspect of this invention is prepared using the preparation method provided in the first aspect of this invention, or it is the pure titanium powder provided in the second aspect of this invention.

[0099] The following detailed description, through specific embodiments, illustrates the method for preparing pure titanium powder from titanium waste and the resulting pure titanium powder.

[0100] Example 1

[0101] The recovered titanium waste is placed inside an ultrasonic cleaning machine. Hot water at 60°C is poured into the machine to submerge the titanium waste and stirred for more than 20 minutes. The hot water is drained, and Na2CO3 solution is added to submerge the titanium waste and heated to 70°C. The mixture is stirred continuously for 30 minutes. After draining the Na2CO3 solution, room temperature water is added and stirred for more than 10 minutes to clean the residual Na2CO3 solution.

[0102] The cleaned residual titanium waste was then subjected to crushing, ball milling, washing, and magnetic separation to obtain a particle size D. 50 =115μm residual titanium waste.

[0103] The cleaned residual titanium waste was then subjected to hydrogenation and dehydrogenation treatment to obtain hydrogenated dehydrogenated titanium powder. The process parameters included: vacuum degree of 0.08 Pa, pressure rise rate within 0.9 Pa / min, maximum positive pressure of 0.11 MPa, pressure drop of less than 5 Pa / min, hydrogenation temperature of 400℃, time of 4 h; ball-to-material ratio of 5:1, rotation speed of 200 rpm; dehydrogenation temperature of 500℃, holding time of 3 h.

[0104] The hydrogenated dehydrogenated titanium powder is then subjected to deoxidation treatment. The deoxidizer has a particle size of 5–20 mm and is a mixture of CaH2, CaCl2, and KCl. The mass ratio of CaH2:CaCl2:KCl is 1:0.075:1.5; the mass ratio of deoxidizer to hydrogenated dehydrogenated titanium powder is 0.15:1. The specific deoxidation process parameters are as follows: the temperature is increased to the reaction temperature of 700℃ at a heating rate of 10℃ / min, the reaction time is 1 hour, and after the reaction is completed, the temperature is cooled to room temperature (25℃) at a cooling rate of 10℃ / min throughout the process under an argon protective atmosphere.

[0105] The deoxidized titanium powder product was acid-washed with 10% hydrochloric acid, washed with pure water, and then placed in a vacuum drying oven and dried at 55°C for 2 hours to obtain pure titanium powder.

[0106] The present invention uses a laser particle size analyzer to test the particle size of the pure titanium powder prepared in Example 1, and uses an ONH5500 analyzer to test the oxygen content of the pure titanium powder prepared in Example 1.

[0107] Test results show that the particle size D of the pure titanium powder in Example 1 is... 50 =47μm, oxygen content is 879ppm.

[0108] Example 2

[0109] The recovered titanium waste is placed inside an ultrasonic cleaning machine. Hot water at 60°C is poured into the machine to submerge the titanium waste and stirred for more than 20 minutes. The hot water is drained, and Na2CO3 solution is added to submerge the titanium waste and heated to 70°C. The mixture is stirred continuously for 30 minutes. After draining the Na2CO3 solution, room temperature water is added and stirred for more than 10 minutes to clean the residual Na2CO3 solution.

[0110] The cleaned residual titanium waste was then subjected to crushing, ball milling, and magnetic separation to obtain a particle size D. 50 =115μm residual titanium waste.

[0111] The cleaned residual titanium waste was then subjected to hydrogenation and dehydrogenation treatment to obtain hydrogenated dehydrogenated titanium powder. The process parameters included: vacuum degree of 0.08 Pa, pressure rise rate within 0.9 Pa / min, maximum positive pressure of 0.13 MPa, pressure drop of less than 5 Pa / min, hydrogenation temperature of 450℃, time of 3 h; ball-to-material ratio of 5:1, rotation speed of 150 rpm; dehydrogenation temperature of 400℃, holding time of 5 h.

[0112] The hydrogenated dehydrogenated titanium powder is then subjected to deoxidation treatment. The deoxidizer has a particle size of 5–20 mm and is a mixture of CaH2, CaCl2, and LiCl, with a CaH2:CaCl2:LiCl mass ratio of 1:0.1:2; the mass ratio of deoxidizer to hydrogenated dehydrogenated titanium powder is 0.15:1. The specific deoxidation process parameters are as follows: the temperature is increased to the reaction temperature of 750℃ at a heating rate of 10℃ / min, the reaction time is 1 hour, and after the reaction is completed, the temperature is cooled to room temperature (25℃) at a cooling rate of 10℃ / min, with argon atmosphere throughout the process.

[0113] The deoxidized titanium powder product was acid-washed with 10% hydrochloric acid, washed with pure water, and then placed in a drying oven and dried at 55°C for 2 hours to obtain pure titanium powder.

[0114] The present invention uses a laser particle size analyzer to test the particle size of the pure titanium powder prepared in Example 2, and uses an ONH5500 analyzer to test the oxygen content of the pure titanium powder prepared in Example 2.

[0115] Test results show that the particle size D of the pure titanium powder in Example 2 is...50 =53μm, oxygen content is 689ppm.

[0116] Example 3

[0117] The recovered titanium waste is placed inside an ultrasonic cleaning machine. Hot water at 60°C is poured into the machine to submerge the titanium waste and stirred for more than 20 minutes. The hot water is drained, and Na2CO3 solution is added to submerge the titanium waste and heated to 70°C. The mixture is stirred continuously for 30 minutes. After draining the Na2CO3 solution, room temperature water is added and stirred for more than 10 minutes to clean the residual Na2CO3 solution.

[0118] The cleaned residual titanium waste was then subjected to crushing, ball milling, washing, and magnetic separation to obtain a particle size D. 50 =115μm residual titanium waste.

[0119] The cleaned residual titanium waste was then subjected to hydrogenation and dehydrogenation treatment to obtain hydrogenated dehydrogenated titanium powder. The process parameters included: vacuum degree of 0.08 Pa, pressure rise rate within 0.9 Pa / min, maximum positive pressure of 0.15 MPa, pressure drop of less than 5 Pa / min, hydrogenation temperature of 500℃, time of 4 h; ball-to-material ratio of 7:1, rotation speed of 300 rpm; dehydrogenation temperature of 500℃, holding time of 3 h.

[0120] The hydrogenated dehydrogenated titanium powder is then subjected to deoxidation treatment. The deoxidizer has a particle size of 5–20 mm and is a mixture of CaH2, CaCl2, and KCl, with a CaH2:CaCl2:KCl mass ratio of 1:1:2; the mass ratio of deoxidizer to hydrogenated dehydrogenated titanium powder is 0.15:1. The specific deoxidation process parameters are as follows: the temperature is increased to the reaction temperature of 800℃ at a heating rate of 10℃ / min, the reaction time is 1 hour, and after the reaction is completed, the temperature is cooled to room temperature (25℃) at a cooling rate of 10℃ / min, with argon atmosphere throughout the process.

[0121] The deoxidized titanium powder product was acid-washed with 10% hydrochloric acid, washed with pure water, and then placed in a drying oven and dried at 55°C for 2 hours to obtain pure titanium powder.

[0122] The present invention uses a laser particle size analyzer to test the particle size of the pure titanium powder prepared in Example 3, and uses an ONH5500 analyzer to test the oxygen content of the pure titanium powder prepared in Example 3.

[0123] Test results show that the particle size D of the pure titanium powder in Example 3 is... 50 =49μm, oxygen content is 563ppm.

[0124] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for preparing pure titanium powder from titanium waste, characterized in that, Includes the following steps: The obtained titanium waste is subjected to hydrogenation and dehydrogenation treatment to obtain hydrogenated dehydrogenated titanium powder. The hydrogenation and dehydrogenation treatment includes sequential hydrogenation, ball milling, and dehydrogenation, wherein: the hydrogenation temperature is 400~700℃, the time is 3~7h, and the furnace pressure is 0.11~0.15Mpa; the ball-to-material ratio of ball milling is 5~10:1, and the rotation speed is 150~300rpm; the dehydrogenation temperature is 400~600℃, and the dehydrogenation time is 1~5h; the particle size of the hydrogenated dehydrogenated titanium powder is 20~70µm. Under a protective atmosphere, the hydrogenated dehydrogenated titanium powder is subjected to a deoxidation reaction with a deoxidizer. The reaction temperature is 600~800℃ and the reaction time is 0.5~2h to obtain a deoxidation product. The deoxidizer is a mixture of CaH2 and chloride salt, and the mass ratio of the deoxidizer to the hydrogenated dehydrogenated titanium powder is (0.15~0.2):

1. The deoxidation product was washed and dried to obtain pure titanium powder.

2. The method for preparing pure titanium powder from titanium waste as described in claim 1, characterized in that, The particle size of the deoxidizer is 5~20mm.

3. The method for preparing pure titanium powder from titanium waste as described in claim 1, characterized in that, In the deoxidizing agent, the mass ratio of CaH2 to the chloride salt is 1:(1.5~2.0).

4. The method for preparing pure titanium powder from titanium waste as described in claim 1, characterized in that, The chloride salt includes a mixture of any one of KCl and LiCl with CaCl2.

5. The method for preparing pure titanium powder from titanium waste as described in claim 4, characterized in that, The mass ratio of CaCl2 to KCl or LiCl is (0.05~0.5):

1.

6. The method for preparing pure titanium powder from titanium waste as described in claim 4, characterized in that, The mass ratio of CaH2 to CaCl2 to KCl or LiCl is 1:(0.075~1):(1.5~2.0).

7. The method for preparing pure titanium powder from titanium waste as described in claim 1, characterized in that, The protective gas used in the deoxygenation reaction includes argon.

8. The method for preparing pure titanium powder from titanium waste as described in claim 1, characterized in that, In the deoxygenation reaction, the heating rate is 10℃ / min, and after the reaction is completed, it is cooled to room temperature at 10℃ / min.

9. The method for preparing pure titanium powder from titanium waste as described in claim 1, characterized in that, The deoxygenation products are subjected to acid washing to remove water-soluble salts and the byproduct CaO.

10. The method for preparing pure titanium powder from titanium waste as described in claim 9, characterized in that, The pickling agents used in pickling include hydrochloric acid.

11. The method for preparing pure titanium powder from titanium waste as described in claim 1, characterized in that, The drying temperature is 55~120℃, and the drying time is 0.5~3h.

12. The method for preparing pure titanium powder from titanium waste as described in claim 1, characterized in that, Before the hydrogenation and dehydrogenation process, the process further includes: sequentially performing surface treatment, crushing, cleaning, and separation on the titanium waste to remove surface impurities and inclusions from the titanium waste.

13. The method for preparing pure titanium powder from titanium waste as described in claim 12, characterized in that, The particle size of the titanium waste after crushing is 50~150µm.

14. Pure titanium powder prepared by the method for preparing pure titanium powder from titanium waste according to any one of claims 1-13, characterized in that, The oxygen content of the pure titanium powder is ≤1000ppm.

15. The application of pure titanium powder prepared by the method for preparing pure titanium powder from titanium waste according to any one of claims 1-13, or the pure titanium powder according to claim 14, in the manufacture of devices for aerospace, additive manufacturing, and marine engineering.