Low-oxygen titanium and a method for producing the same

Abstract

The application discloses low-oxygen titanium and a preparation method thereof. The preparation method comprises the following steps: S100, a segmented heating reaction is performed on a titanium source containing oxygen and a metal reducing agent in a mixed atmosphere of argon and hydrogen to obtain a first mixture; after the reaction is completed, the first mixture is placed in a vacuum environment and then in an argon atmosphere, wherein the size of the titanium source is greater than or equal to 60 microns, the size of the metal reducing agent is less than or equal to 10 mm and greater than or equal to 1 mm, and the reducing property of the metal reducing agent is greater than that of elemental titanium; S200, a product with a size less than 1 mm in the first mixture is separated to obtain a second mixture; S300, the second mixture is ground in an argon atmosphere to obtain a third mixture with a size of 1 microns to 60 microns; S400, a buffer material is introduced into the third mixture in an argon atmosphere, and a fourth mixture with a size less than or equal to 25 microns is obtained through spheroidization treatment; and S500, the fourth mixture is subjected to dehydrogenation treatment to obtain low-oxygen titanium.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of titanium preparation, in particular to a low-oxygen titanium and a preparation method thereof. BACKGROUND

[0002] Titanium has high activity and is easy to form an oxide layer, such as a titanium dioxide (TiO2) layer, on the surface. The increase in interstitial oxygen content further causes an "oxygen embrittlement effect", which significantly reduces the ductility and fracture toughness of titanium alloy materials. On the other hand, the extraction and production cost of titanium is high, which seriously restricts its application in a wider field.

[0003] At the same time, the existing magnesium hot reduction method uses a large amount of chlorine gas as a raw material in preparation and needs to carry out a reduction reaction under high temperature and closed conditions, and the reaction conditions are relatively harsh, so the production cost is high. When calcium or rare earth metals are used for reduction, the amount used is large and the reaction time is long, further increasing the production cost. Therefore, it is urgent to prepare and develop a low-oxygen titanium with a safe production process, a lower production cost and a higher purity, and a preparation method thereof. SUMMARY

[0004] One object of the present application is to provide a low-oxygen titanium and a preparation method thereof, which is beneficial to improve the purity of the low-oxygen titanium, reduce the oxygen content of the low-oxygen titanium product, and improve the safety in the preparation process.

[0005] Another object of the present application is to provide a low-oxygen titanium and a preparation method thereof, which is beneficial to reduce the production cost, increase the environmental friendliness, and further improve the economic benefit.

[0006] To achieve the above objects, the technical scheme adopted by the present application is as follows: a preparation method of a low-oxygen titanium, comprising the steps of:

[0007] S100, subjecting a titanium source containing oxygen and a metal reducing agent to a staged heating reaction under a mixed atmosphere of argon and hydrogen to obtain a first mixture, and then placing the first mixture in a vacuum environment and then in an argon atmosphere after the reaction is completed, wherein the size of the titanium source is ≥ 60 μm, the size of the metal reducing agent is ≤ 10 mm and ≥ 1 mm, and the reducing property of the metal reducing agent is greater than that of elemental titanium;

[0008] S200, separating the product with a size < 1 mm in the first mixture to obtain a second mixture;

[0009] S300, grinding the second mixture in an argon atmosphere to obtain a third mixture with a size of 1 μm to 60 μm;

[0010] S400, introducing a buffer material into the third mixture in an argon atmosphere, and obtaining a fourth mixture with a size ≤ 25 μm after spheroidization treatment.

[0011] S500, performing dehydrogenation treatment on the fourth mixture to obtain low-oxygen titanium.

[0012] In some embodiments, the step S100 further comprises:

[0013] S110, heating the oxygen-containing titanium source and the metal reducing agent to 180-250℃, at this time, the flow rate of hydrogen is 1.5-2.5 L / min, the ratio between the flow rate of argon and the flow rate of hydrogen is (0.2-0.8):1, and the first reactant is obtained after 0.5-1.5 h of reaction;

[0014] S120, heating the first reactant to 250-350℃, at this time, the flow rate of hydrogen is 0.5-2.0 L / min, the ratio between the flow rate of argon and the flow rate of hydrogen is (0.5-1):1, and the second reactant is obtained after 0.5-2 h of reaction;

[0015] S130, heating the second reactant to 350-550℃, at this time, the flow rate of hydrogen is 0.5-1.2 L / min, the ratio between the flow rate of argon and the flow rate of hydrogen is (0.8-1.2):1, and the third reactant is obtained after 0.5-1.5 h of reaction;

[0016] S140, heating the third reactant to 450-900℃, at this time, the flow rate of hydrogen is 0.1-0.5 L / min, the ratio between the flow rate of argon and the flow rate of hydrogen is (2-4):1, and the first mixture is obtained after 0.5-1.5 h of reaction.

[0017] In some embodiments, the step S300 further comprises:

[0018] S310, grinding the second mixture in an argon atmosphere to obtain a first broken product with a size of no more than 80 μm;

[0019] S320, placing the first broken product in an argon stream with a temperature of 150-200℃ and a flow rate of 100-500 m / s for jet milling to obtain a second broken product;

[0020] S330, re-feeding the product with a size >60 μm in the second broken product to the second mixture in step S200 by a cyclone separator, and the product with a size ≤60 μm is the third mixture.

[0021] In some embodiments, the metal reducing agent is a hydride of a reactive metal; the reactive metal is one or more of potassium, calcium, sodium, and magnesium.

[0022] In some embodiments, step S400 further includes:

[0023] S410. In an argon atmosphere, a buffer material and grinding balls are added to the third mixture. The grinding balls rotate at a speed of 150 rpm to 350 rpm, the spheroidizing temperature is ≤40℃, and the spheroidizing time is 1 h to 4 h to obtain the third fragmentation product.

[0024] S420. In an argon atmosphere, the third fragmentation product is heated to 500°C~900°C to obtain the fourth reactant.

[0025] S430. Under an argon atmosphere, the fourth reactant is washed in a dilute hydrochloric acid solution at a temperature of 10°C to 60°C for 5 min to 10 min, and then dried to obtain the fourth mixture.

[0026] In some embodiments, the buffer material is a stearic acid-nano calcium carbonate core-shell material, the mass ratio of the buffer material to the third mixture is (0.010~0.015):1, the mass ratio of the third mixture to the grinding ball is 1:(5.0~9.0), and the mass fraction of hydrogen chloride in the dilute hydrochloric acid is ≤5% (wt.%).

[0027] In some embodiments, the method for preparing the stearic acid-nano calcium carbonate core-shell material includes the following steps:

[0028] A100. Sonicate the dried nano-calcium carbonate in anhydrous ethanol for 10 min to 30 min to obtain the first solution. Dissolve stearic acid in anhydrous ethanol and stir to form the second solution.

[0029] A200. Under alkaline conditions, the second solution is added to the first solution, heated and stirred, and the fifth mixture is obtained by separation.

[0030] A300. The fifth mixture is washed with anhydrous ethanol and dried at a temperature of 50°C to 80°C to obtain stearic acid-nano calcium carbonate core-shell material.

[0031] In some embodiments, the temperature of the grinding process in step S310 is ≤40°C.

[0032] In some embodiments, step S500 further includes: performing a dehydrogenation treatment on the fourth mixture in a vacuum at 200°C to 400°C to obtain low-oxygen titanium.

[0033] To achieve the above objectives, this application also provides low-oxygen titanium prepared by the aforementioned preparation method.

[0034] Compared with the prior art, the beneficial effects of this application are as follows:

[0035] (1) This application reduces the risk of decomposition of the metal reducing agent by staged heating of oxygen-containing titanium powder and metal reducing agent, thereby further reducing the oxygen content of low-oxygen titanium products. At the same time, hydrogen and argon with different flow rate ratios are used in different stages of staged heating. In the low-temperature stage, it is beneficial to activate the metal reducing agent and inhibit its premature decomposition, preferentially reducing oxygen-containing titanium powder and forming surface oxygen vacancies, increasing the specific surface area and providing diffusion channels for subsequent deep deoxidation. In the medium-temperature stage, oxygen-containing titanium powder is deeply deoxidized and the generation of titanium hydride is inhibited. In the high-temperature stage, the high argon flow rate can carry away some by-products and further avoid hydrogen embrittlement.

[0036] (2) This application uses a stearic acid-nano-calcium carbonate core-shell material as a buffer material for the spheroidization process. The long-chain alkyl groups in stearic acid can significantly reduce the friction coefficient between titanium powder particles, reduce the risk of cold welding, and help reduce energy consumption during the spheroidization process, thereby further improving the spheroidization rate of titanium powder. On the other hand, using nano-calcium carbonate with good mechanical properties as a core material allows it to roll between titanium powder particles during the spheroidization process, which helps to disperse local stress, thereby enhancing the spheroidization effect and improving the performance of low-oxygen titanium. Detailed Implementation

[0037] The present application will be further described below with reference to specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0038] As used herein, the terms “prepared from” and “comprising” are synonymous. The terms “comprising,” “including,” “having,” “containing,” or any other variation thereof, as used herein, are intended to cover non-exclusive inclusion. For example, a composition, step, method, article, or apparatus that includes the listed elements is not necessarily limited to those elements and may include other elements not expressly listed or elements inherent to such composition, step, method, article, or apparatus.

[0039] When a quantity, concentration, or parameter is expressed as a range, a preferred range, or a range defined by a series of upper and lower preferred values, this should be understood as specifically disclosing any pair of any upper or preferred value with any lower or preferred value, regardless of whether the range is disclosed individually. For example, when the range is disclosed as “1 to 5”, the described range should be interpreted as including ranges “1 to 4”, “1 to 3”, “1 to 2 and 4 to 5”, “1 to 3 and 5”, etc. When numerical ranges are described herein, unless otherwise stated, the range includes its endpoints and all integers and fractions within that range.

[0040] Approximate terms used in the specification and claims to modify quantities indicate that the invention is not limited to that specific quantity, but also includes acceptable modifications close to that quantity that do not alter the relevant essential function. Correspondingly, the use of "about," "approximately," etc., to modify a numerical value means that the invention is not limited to that precise value. In some instances, approximate terms may correspond to the precision of the instrument used to measure the value. In this application's specification and claims, scope definitions can be combined and / or interchanged, unless otherwise stated, these scopes include all subscopes contained therein.

[0041] To achieve the above objectives, the technical solution adopted in this application is: a method for preparing low-oxygen titanium, comprising the following steps:

[0042] S100. The oxygen-containing titanium source and the metal reducing agent are subjected to a staged heating reaction in a mixed atmosphere of argon and hydrogen to obtain a first mixture. After the reaction is completed, the first mixture is placed in a vacuum environment and then in an argon atmosphere. The titanium source has a size ≥ 60 μm, the metal reducing agent has a size ≤ 10 mm and a size ≥ 1 mm, and the reducing power of the metal reducing agent is greater than that of elemental titanium.

[0043] S200, Separate the product with a size <1mm from the first mixture to obtain the second mixture;

[0044] S300, grind the second mixture in an argon atmosphere to obtain a third mixture with a size of 1μm~60μm;

[0045] S400. In an argon atmosphere, a buffer material is introduced into the third mixture, and after spheroidization treatment, a fourth mixture with a size ≤25μm is obtained.

[0046] S500, the fourth mixture is subjected to dehydrogenation treatment to obtain low-oxygen titanium.

[0047] This application utilizes a staged heating process in a mixed atmosphere of hydrogen and argon to reduce an oxygen-containing titanium source, which is beneficial for obtaining high-purity, low-oxygen titanium. Firstly, since the size of both the oxygen-containing titanium source and the reduced intermediate products is smaller than that of the metal reducing agent, and the size difference is significant, physical methods can be used for separation and sieving, reducing separation difficulty and further increasing the purity of subsequent products. Secondly, since the grinding and spheroidizing steps are carried out in an argon atmosphere, production costs are reduced, the reduced titanium is prevented from being re-oxidized, and the risk of titanium hydride formation is also reduced. Simultaneously, the argon obtained after separating the collected waste gas can be reused in the production process. It is understood that grinding provides materials with a more uniform size distribution for spheroidizing, thereby improving the processing efficiency. Notably, using a buffer material in the spheroidizing process of the third mixture reduces the risk of cold welding, which helps reduce energy consumption during spheroidizing and further improves the spheroidization rate of the titanium powder.

[0048] In some embodiments, step S100 further includes:

[0049] S110. Heat the oxygen-containing titanium source and metal reducing agent to 180℃~250℃. At this time, the flow rate of hydrogen is 1.5L / min~2.5L / min, and the ratio between the flow rate of argon and the flow rate of hydrogen is (0.2~0.8):1. After reacting for 0.5h~1.5h, the first reactant is obtained.

[0050] S120. The first reactant is heated to 250℃~350℃, at which point the flow rate of hydrogen is 0.5L / min~2.0L / min, and the ratio of the flow rate of argon to the flow rate of hydrogen is (0.5~1):1. The second reactant is obtained after reacting for 0.5h~2h.

[0051] S130. The second reactant is heated to 350℃~550℃, at which point the flow rate of hydrogen is 0.5L / min~1.2L / min, and the ratio of the flow rate of argon to that of hydrogen is (0.8~1.2):1. After reacting for 0.5h~1.5h, the third reactant is obtained.

[0052] S140. The third reactant is heated to 450℃~900℃. At this time, the flow rate of hydrogen is 0.1L / min~0.5L / min, and the ratio between the flow rate of argon and the flow rate of hydrogen is (2~4):1. After reacting for 0.5h~1.5h, the first mixture is obtained.

[0053] Understandably, using different flow rates of hydrogen and argon at different stages of segmented heating is beneficial in the low-temperature stage. At low temperatures, this helps activate the metal reducing agent and inhibits its premature decomposition. Furthermore, active hydrogen atoms can preferentially reduce oxygen-containing titanium powder and form oxygen vacancies on its surface, increasing the specific surface area and providing diffusion channels for subsequent deep deoxidation. On the other hand, to ensure the effective progress of the reduction reaction, the introduction of a large amount of hydrogen can keep the metal reducing agent highly active and help maintain an oxygen-free environment, further increasing the degree of reduction. In the intermediate-temperature stage, to deeply deoxidize the first and second reactants and inhibit the formation of titanium hydride, the argon flow rate is increased to balance the reduction rate and suppress side reactions. In the medium-high temperature stage, the reduction reaction is about to end. To prevent excessive hydrogen from forming titanium hydride and thus increasing the argon flow rate, it also avoids grain coarsening due to localized overheating. During the high-temperature stage, the argon flow rate is higher than the hydrogen flow rate. At this time, the trace amount of hydrogen maintains the surface activity of the reduced titanium, promotes the diffusion of lattice oxygen to the surface and its combination with the metal reducing agent. The high-flow-rate argon can also carry away some by-products, further avoiding hydrogen embrittlement.

[0054] It is worth mentioning that in the later stage of the reduction reaction, the content of argon in the system is greater than that of hydrogen. Since the subsequent grinding process needs to be carried out in an argon environment, the increased argon flow rate is beneficial to quickly change the system atmosphere when changing the atmosphere in the later stage of the reduction reaction, thereby improving production efficiency and operational safety.

[0055] In some embodiments, step S300 further includes:

[0056] S310. Grind the second mixture in an argon atmosphere to obtain a first fragmented product with a size not greater than 80 μm.

[0057] S320. The first crushed product is placed in an argon flow at a temperature of 150℃~200℃ and a flow rate of 100m / s~500m / s for air jet milling to obtain the second crushed product.

[0058] S330. The product with a size > 60 μm in the second crushed product is re-transported to the second mixture in step S200 through a cyclone separator, and the product with a size ≤ 60 μm is the third mixture.

[0059] By mechanically grinding and then performing air jet milling on the second mixture after preliminary reduction, titanium powder can be finely refined in an oxygen-free environment, which is beneficial for obtaining titanium powder with low oxygen content. It is worth mentioning that mechanical grinding provides the first fragmented product with a uniform size distribution for air jet milling, which is beneficial for obtaining a more uniformly distributed product through air jet milling. Furthermore, since the system atmosphere is argon, the surface of the newly generated titanium after grinding is immediately protected by argon, thereby reducing the oxygen increment in the second fragmented product.

[0060] It is understandable that the second crushed product obtained by air jet milling is then screened out by cyclone separation to remove products of suitable size, and the large titanium powder is sent back to the grinding step for reprocessing. This is beneficial to obtain titanium powder products with uniform size and further improve the performance of low oxygen titanium products.

[0061] In some embodiments, the metal reducing agent is a hydride of an active metal; the active metal is one or more elements selected from potassium, calcium, sodium, and magnesium. It is worth noting that when a metal hydride is used as a reducing agent, since the reduction reaction is carried out under elevated temperature conditions, some of the metal hydride can also act as a hydrogen source to release hydrogen gas, further reducing the amount of hydrogen used, reducing production costs, and thus increasing economic benefits.

[0062] In some embodiments, step S400 further includes:

[0063] S410. In an argon atmosphere, a buffer material and grinding balls are added to the third mixture. The grinding ball speed is 150 rpm to 350 rpm, the spheroidizing temperature is ≤40℃, and the spheroidizing time is 1 h to 4 h to obtain the third fragmentation product.

[0064] S420. In an argon atmosphere, the third fragmentation product is heated to 500℃~900℃ to obtain the fourth reactant.

[0065] S430. Under an argon atmosphere, the fourth reactant is washed in a dilute hydrochloric acid solution at a temperature of 10℃ to 60℃ for 5 min to 10 min. After drying, the fourth mixture is obtained.

[0066] It is understandable that low-temperature spheroidization treatment helps balance spheroidization efficiency and suppress cold welding. On the other hand, low-temperature treatment helps enhance the stability of the buffer material and reduces the risk of decomposition. Based on this, heating the third crushing product can decompose at least a portion of the buffer material and the remaining impurities. Then, acid washing removes non-target products, thereby improving the purity of low-oxygen titanium in the resulting fourth mixture.

[0067] In some embodiments, the buffer material is a stearic acid-nano-calcium carbonate core-shell material, with a mass ratio of the buffer material to the third mixture of (0.010~0.015):1, and a mass ratio of the third mixture to the grinding balls of 1:(5.0~9.0). The mass fraction of hydrogen chloride in the dilute hydrochloric acid is ≤5% (wt.%). It is worth noting that the buffer material prepared by coating nano-calcium carbonate with stearic acid has a core portion composed of nano-calcium carbonate that enhances the grinding effect during spheroidization, disperses impact stress, and further suppresses cold welding. The shell layer composed of stearic acid enhances lubrication and stress buffering. In other words, because the spheroidization process is carried out at low temperatures, the risk of deformation or even decomposition of the stearic acid in the shell layer is reduced.

[0068] In some embodiments, the preparation method of stearic acid-nano-calcium carbonate core-shell material includes the following steps:

[0069] A100. Sonicate the dried nano-calcium carbonate in anhydrous ethanol for 10 min to 30 min to obtain the first solution. Dissolve stearic acid in anhydrous ethanol and stir to form the second solution.

[0070] A200. Under alkaline conditions, the second solution is added to the first solution, heated and stirred, and the fifth mixture is obtained by separation.

[0071] A300: Wash the fifth mixture with anhydrous ethanol and dry it at a temperature of 50℃~80℃ to obtain stearic acid-nano calcium carbonate core-shell material.

[0072] Through appropriate preparation steps, the stearic acid-nano calcium carbonate core-shell material obtained has good performance characteristics, and when used in spheroidization treatment, it enhances the performance and dimensional uniformity of the obtained low-oxygen titanium.

[0073] In some embodiments, the grinding temperature in step S310 is ≤40°C. It should be understood that grinding at low temperatures not only reduces the risk of cold welding and suppresses plastic deformation, but also reduces the formation of titanium hydride. Specifically, when titanium hydride decomposes or reabsorbs hydrogen, it releases hydrogen in an atomic state into the titanium matrix, triggering hydrogen embrittlement and significantly reducing the impact toughness of the product. Therefore, reducing the risk of titanium hydride formation helps reduce the difficulty of post-processing and further improves the purity of low-oxygen titanium.

[0074] In some embodiments, step S500 further includes: dehydrogenating the fourth mixture in a vacuum at 200°C to 400°C to obtain low-oxygen titanium. The dehydrogenation process is completed in one step, and no additional pollutants are generated during the entire process, thus exhibiting good environmental friendliness.

[0075] To achieve the above objectives, this application also provides low-oxygen titanium prepared by the aforementioned method. The low-oxygen titanium prepared by the method provided in this application exhibits high purity and good performance in use.

[0076] Example 1

[0077] A method for preparing low-oxygen titanium, comprising the following steps:

[0078] (1) 100g of oxygen-containing titanium source and 2g of calcium hydride were heated to 220℃. At this time, the flow rate of hydrogen was 2.0L / min and the ratio of the flow rate of argon to that of hydrogen was 0.6:1. After reacting for 1.0h, the first reactant was obtained. The first reactant was heated to 320℃. At this time, the flow rate of hydrogen was 1.2L / min and the ratio of the flow rate of argon to that of hydrogen was 0.6:1. After reacting for 1.5h, the second reactant was obtained. The second reactant was heated to 500℃. At this time, the flow rate of hydrogen was 0.9L / min and the ratio of the flow rate of argon to that of hydrogen was 1:1. After reacting for 1.0h, the third reactant was obtained. The third reactant was heated to 800℃. At this time, the flow rate of hydrogen was 0.3L / min and the ratio of the flow rate of argon to that of hydrogen was 3:1. After reacting for 1.0h, the first mixture was obtained.

[0079] (2) Physical sieving is used to obtain the product with a size <1mm in the first mixture, and the second mixture is obtained.

[0080] (3) Grind the second mixture in an argon atmosphere to obtain a first broken product with a size not greater than 80 μm; place the first broken product in an argon flow at a temperature of 180℃ and a flow rate of 300 m / s for air jet milling to obtain a second broken product; and transfer the product with a size > 60 μm in the second broken product back to the second mixture through a cyclone separator, and the product with a size ≤ 60 μm is the third mixture.

[0081] (4) In an argon atmosphere, 0.8 g of stearic acid-nano calcium carbonate core-shell material and grinding balls were added to the third mixture. The grinding ball speed was 280 rpm, the spheroidizing temperature was 20℃, and the spheroidizing time was 3 h to obtain the third crushed product. In an argon atmosphere, the third crushed product was heated to 850℃ to obtain the fourth reactant. In an argon atmosphere, the fourth reactant was placed in a dilute hydrochloric acid solution with a mass fraction of 3% (wt.%) of hydrogen chloride for washing. The washing temperature was 20℃, the washing time was 8 min, and the fourth mixture was obtained after drying.

[0082] (5) Remove hydrogen from the fourth mixture in a vacuum at 300°C to obtain low-oxygen titanium.

[0083] Example 2

[0084] The difference between Example 2 and Example 1 is that in step (1), 100g of oxygen-containing titanium source and 2g of magnesium hydride are heated to 220°C.

[0085] Example 3

[0086] The difference between Example 3 and Example 1 is that in step (1), 100g of oxygen-containing titanium source and 2g of elemental magnesium are heated to 220°C.

[0087] Example 4

[0088] The difference between Example 4 and Example 1 is that step (1) is as follows: 100g of oxygen-containing titanium source and 2g of calcium hydride are heated to 220℃, at which point the hydrogen flow rate is 2.0L / min, and the ratio of the argon flow rate to the hydrogen flow rate is 0.4:1. After reacting for 1.0h, the first reactant is obtained; the first reactant is then heated to 320℃, at which point the hydrogen flow rate is 1.2L / min, and the ratio of the argon flow rate to the hydrogen flow rate is 0.4:1. 1. After reacting for 1.5 h, a second reactant is obtained. The second reactant is heated to 500 °C, at which point the flow rate of hydrogen is 0.9 L / min and the ratio of the flow rate of argon to hydrogen is 0.6:1. After reacting for 1.0 h, a third reactant is obtained. The third reactant is heated to 800 °C, at which point the flow rate of hydrogen is 0.3 L / min and the ratio of the flow rate of argon to hydrogen is 1:1. After reacting for 1.0 h, a first mixture is obtained.

[0089] Example 5

[0090] The difference between Example 5 and Example 1 is that step (1) is as follows: 100g of oxygen-containing titanium source and 2g of calcium hydride are heated to 220°C, at which point the hydrogen flow rate is 2.0L / min, and the ratio of the argon flow rate to the hydrogen flow rate is 0.8:1. After reacting for 1.0h, the first reactant is obtained; the first reactant is then heated to 320°C, at which point the hydrogen flow rate is 1.2L / min, and the ratio of the argon flow rate to the hydrogen flow rate is 0.8:1. 1. After reacting for 1.5 h, a second reactant is obtained. The second reactant is heated to 500 °C, at which point the flow rate of hydrogen is 0.9 L / min, and the ratio of the flow rate of argon to hydrogen is 1.2:1. After reacting for 1.0 h, a third reactant is obtained. The third reactant is heated to 800 °C, at which point the flow rate of hydrogen is 0.3 L / min, and the ratio of the flow rate of argon to hydrogen is 4:1. After reacting for 1.0 h, a first mixture is obtained.

[0091] Example 6

[0092] The difference between Example 6 and Example 1 is that the buffer material in step (4) is polypropylene.

[0093] Example 7

[0094] The difference between Example 7 and Example 1 is that the buffer material in step (4) is nano-calcium carbonate.

[0095] Comparative Example 1

[0096] The difference between Comparative Example 1 and Example 1 is that no cushioning material was used in step (4).

[0097] Comparative Example 2

[0098] The difference between Comparative Example 2 and Example 1 is that the flow rate ratio of hydrogen to argon in the gas atmosphere in step (1) is kept constant at 0.5:1.

[0099] Performance testing

[0100] The low-oxygen titanium prepared in Examples 1 to 7 and Comparative Examples 1 to 2 was tested using pulsed molten oxygen analysis and scanning electron microscopy. The test results are shown in Table 1.

[0101] Table 1: Performance Tests of Low-Oxygen Titanium

[0102]

[0103] As shown in Examples 1 to 3 of Table 1, selecting a suitable metal reducing agent is beneficial for obtaining low-oxygen titanium with uniform distribution and high purity. Meanwhile, Examples 1 and 4 to 5 show that using hydrogen and argon at different flow rate ratios at different stages of the reduction reaction is beneficial for enhancing the reduction degree of oxygen-containing titanium powder and further reducing the oxygen content in the low-oxygen titanium.

[0104] Understandably, by using suitable buffering materials to grind titanium powder, low-oxygen titanium with good uniformity in use can be obtained.

[0105] The basic principles, main features, and advantages of this application have been described above. Those skilled in the art should understand that this application is not limited to the above embodiments. The embodiments and descriptions in the specification are merely the principles of this application. Various changes and modifications can be made to this application without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claims. The scope of protection claimed by this application is defined by the appended claims and their equivalents.

Claims

1. A method for producing low-oxygen titanium, characterized by, The method comprises the steps of: S100, subjecting a titanium source containing oxygen and a metal reducing agent to a staged heating reaction under a mixed atmosphere of argon and hydrogen to obtain a first mixture, and placing the first mixture in a vacuum environment and then in an argon atmosphere after the reaction is completed, wherein the size of the titanium source is ≥60 μm, the size of the metal reducing agent is ≤10 mm and ≥1 mm, and the reducing property of the metal reducing agent is greater than that of elemental titanium; S200, separating the product with a size <1 mm in the first mixture to obtain a second mixture; S300, grinding the second mixture in an argon atmosphere to obtain a third mixture with a size of 1 μm-60 μm; S400, introducing a buffer material into the third mixture in an argon atmosphere, and obtaining a fourth mixture with a size ≤25 μm after spheroidization treatment; S500, subjecting the fourth mixture to dehydrogenation treatment to obtain low-oxygen titanium; and The step S100 further comprises: S110, heating the titanium source containing oxygen and the metal reducing agent to 180-250°C, at this time, the flow rate of hydrogen is 1.5-2.5 L / min, the ratio between the flow rate of argon and the flow rate of hydrogen is (0.2-0.8):1, and the first reactant is obtained after reaction for 0.5-1.5 h; S120, heating the first reactant to 250-350°C, at this time, the flow rate of hydrogen is 0.5-2.0 L / min, the ratio between the flow rate of argon and the flow rate of hydrogen is (0.5-1):1, and the second reactant is obtained after reaction for 0.5-2 h; S130, heating the second reactant to 350-550°C, at this time, the flow rate of hydrogen is 0.5-1.2 L / min, the ratio between the flow rate of argon and the flow rate of hydrogen is (0.8-1.2):1, and the third reactant is obtained after reaction for 0.5-1.5 h; S140, heating the third reactant to 450-900°C, at this time, the flow rate of hydrogen is 0.1-0.5 L / min, the ratio between the flow rate of argon and the flow rate of hydrogen is (2-4):1, and the first mixture is obtained after reaction for 0.5-1.5 h.

2. The production method according to claim 1, characterized by, The step S300 further comprises: S310, grinding the second mixture in an argon atmosphere to obtain a first broken product with a size not greater than 80 μm; S320, subjecting the first broken product to air-jet milling in an argon gas stream with a temperature of 150-200°C and a flow rate of 100-500 m / s to obtain a second broken product; S330, re-feeding the product with a size >60 μm in the second broken product to the second mixture in step S200 through a cyclone separator, and the product with a size ≤60 μm is the third mixture.

3. The preparation method according to claim 1, characterized in that, The metal reducing agent is a hydride of a reactive metal, and the reactive metal is one or more of potassium, calcium, sodium and magnesium.

4. The method of claim 1, wherein, The step S400 further comprises: S410, adding buffer material and grinding balls to the third mixture in an argon atmosphere, the grinding balls rotating at a speed of 150 rpm-350 rpm, the spheroidization temperature being ≤40℃, and the spheroidization time being 1h-4h, to obtain a third broken product; S420, heating the third broken product to 500℃-900℃ in an argon atmosphere to obtain a fourth reactant; S430, washing the fourth reactant in a dilute hydrochloric acid solution in an argon atmosphere, the washing temperature being 10℃-60℃, the washing time being 5min-10min, and the fourth mixture being obtained after drying.

5. The preparation method according to claim 4, characterized in that, The buffer material is a stearic acid-nano calcium carbonate core-shell material, the mass ratio of the buffer material to the third mixture being (0.010-0.015):1, the mass ratio of the third mixture to the grinding balls being 1:(5.0-9.0), and the mass fraction of hydrogen chloride in the dilute hydrochloric acid being ≤5% (wt.%).

6. The preparation method according to claim 5, characterized in that, The preparation method of the stearic acid-nano calcium carbonate core-shell material comprises the following steps: A100, ultrasonically treating dried nano calcium carbonate in anhydrous ethanol for 10min-30min to obtain a first solution, and dissolving stearic acid in anhydrous ethanol to form a second solution; A200, adding the second solution to the first solution under an alkaline environment, heating and stirring to separate a fifth mixture; A300, washing the fifth mixture with anhydrous ethanol and drying at a temperature of 50℃-80℃ to obtain the stearic acid-nano calcium carbonate core-shell material.

7. The preparation method according to claim 2, characterized in that, The temperature of the grinding treatment in step S310 is ≤40℃.

8. The method of claim 1, wherein, The step S500 further comprises dehydrogenating the fourth mixture in a vacuum at 200℃-400℃ to obtain low-oxygen titanium.

9. A low-oxygen titanium, characterized in that, Prepared by the preparation method of any one of claims 1-8. Prepared by the preparation method of any one of claims 1-8.

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