Method for preparing coarse-particle tungsten powder

Abstract

The invention relates to the technical field of powder metallurgy tungsten powder production, and discloses a method for preparing coarse particle tungsten powder, which comprises the following steps: S1, proportioning: selecting tungsten oxide powder and activating agent nickel oxide powder; s2, ball milling, wherein grinding balls are adopted for grinding and mixing; s3, loading and reducing, namely loading and flatly paving by using a boat, and putting the boat into a heating furnace; s4, crushing and sieving: grinding and crushing, and then sieving; s5, nickel is removed, the tungsten powder is put into hydrochloric acid to react after being sieved, nickel powder in the tungsten powder is removed, and a coarse tungsten powder wet material is obtained; and S6, drying and detection are conducted, specifically, the coarse tungsten powder wet material is washed with deionized water and then dried. Tungsten powder particles are continuously dissolved and separated out in an activating agent nickel melt, so that the tungsten powder particles continuously grow up to generate coarse-particle tungsten powder, the tungsten powder particles are further grown up through rapid dissolution in the melt and continuous separation on the surfaces of the tungsten powder particles, the growing speed is high, the efficiency is high, the process for preparing the coarse-particle tungsten powder is simple to operate and easy to control, and the production cost is low. The industrial production can be realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of tungsten powder production by powder metallurgy, in particular to a method for preparing coarse-grained tungsten powder. BACKGROUND

[0002] Coarse-grained tungsten powder is used to make coarse-grained cemented carbide, which has good wear resistance, toughness, and thermal shock resistance and thermal fatigue resistance, and is widely used in oil drilling, rock drilling tools, coal cutting machine teeth, cold planer teeth, shield cutter, and other mining tools. It can significantly improve the service life and mining efficiency of mining tools. The manufacturing method of coarse-grained tungsten powder is constantly improved and updated. In summary, there are currently the following methods:

[0003] High-temperature H2 reduction method using tungsten oxide: the traditional method is to calcine ammonium paratungstate to obtain yellow tungsten oxide (WO 3) or blue tungsten oxide (WO 2.9) Hydrogen reduction in a two-zone molybdenum wire furnace at a temperature of 1200-1300℃. This method has the characteristics of fewer pseudo-particles, but has the disadvantages of low yield, high energy consumption, high reduction equipment requirements, and high manufacturing cost. The "braised hydrogen" process developed by Zhuzhou Cemented Carbide Factory also belongs to this method.

[0004] (2) Mid-temperature reduction of tungsten oxide mixed with lithium salt: This process began to rise in the mid-1980s and replaced most of the traditional processes. Many manufacturers and research institutions have researched this method and described its principle: by adding volatile Li salt, the volatilization and deposition rate in the reduction process of tungsten oxide is accelerated, so that the tungsten can grow. This process has the characteristics of increased yield and low reduction equipment requirements, but the furnace tube and boat are severely corroded, the impurity content is high, and there are many pseudo-particles, especially the lithium salt is difficult to volatilize, which leads to the product being prone to moisture absorption. Most domestic manufacturers use this method.

[0005] (3) Adding sodium salt and potassium salt method: Add sodium salt, potassium salt, and other alkali metals to tungsten oxide, and then reduce at a higher temperature to obtain coarse-grained tungsten powder. This process has the characteristics of increased yield and low reduction equipment requirements, and the sodium salt and potassium salt are easy to volatilize, and the product is not prone to moisture absorption, but the furnace tube and boat are severely corroded, the impurity content is high, and there are many pseudo-particles.

[0006] (4) Hydrogen reduction method of halide boiling layer: This method is to reduce tungsten chloride or fluoride in the boiling layer with hydrogen. First, hydrogen and raw tungsten powder are sent to the bottom of the reactor to form a tungsten boiling layer, and tungsten halide is introduced into the reactor from the upper part of the reactor and is reduced to tungsten powder by hydrogen at a given optimal temperature and deposited on the raw tungsten powder, resulting in the growth of the raw tungsten powder.

[0007] The existing process has the problems of slow growth rate of tungsten powder particles, low efficiency, complex process operation, high proportion of false particles, difficult to control, and unable to realize industrial production. SUMMARY

[0008] In view of the problems of the prior art, the present application provides a method for preparing coarse-grained tungsten powder, which solves the problems of slow growth rate of tungsten powder particles, low efficiency, complex process operation, high proportion of false particles, difficult to control, and unable to realize industrial production.

[0009] To achieve the above object, the present application is realized by the following technical scheme: a method for preparing coarse-grained tungsten powder, comprising the following steps:

[0010] S1: batching, selecting tungsten oxide powder and activator nickel oxide powder, and batching according to the mass ratio;

[0011] S2: ball milling, putting the mixed mixture of tungsten oxide powder and activator nickel oxide powder prepared in step S1 into a ball milling cylinder, and grinding with grinding balls to obtain uniformly mixed powder;

[0012] S3: charging and reducing, discharging the mixed powder after ball milling in step S2, and using a boat to hold and lay flat, and putting the boat into a heating furnace, and introducing hydrogen into the heating furnace for reduction, in the reduction process, the tungsten oxide is reduced to tungsten powder, the nickel oxide is reduced to nickel melt, the tungsten powder particles are dissolved in the nickel melt and precipitated on the surface of the tungsten particles to realize particle growth, and a product containing tungsten powder and nickel melt is obtained;

[0013] S4: crushing and sieving, grinding and crushing the product after reduction in step S3, and then sieving;

[0014] S5: nickel removal, putting the sieved product in step S4 into hydrochloric acid for reaction to remove nickel powder in the tungsten powder, and filtering after the reaction is completed to obtain coarse tungsten powder wet material;

[0015] S6: drying and detection, washing the coarse tungsten powder wet material obtained in step S5 with deionized water and drying, and detecting the tungsten powder after drying for Fisher particle size and scanning electron microscope image.

[0016] Preferably, in step S1, the tungsten oxide powder is yellow tungsten trioxide or blue tungsten oxide, and the particle size of the tungsten oxide powder is 10-28 μm.

[0017] Preferably, in step S1, the particle size of the activator nickel oxide powder is 1-10 μm, and the mass fraction of the activator nickel oxide is 0-15%.

[0018] Preferably, in the step S2, the ball milling barrel is a 0.5 liter ball milling barrel, the grinding ball is an alloy ball, the ball-to-material ratio is controlled to be (1-4):1, the ball milling time is 6-20 hours, and the amount of the alloy ball is 100-400 g.

[0019] Preferably, in the step S3, the boat is a corundum boat, and the heating furnace is a tube furnace; the tube furnace is vacuumized before the hydrogen is introduced, and the temperature is raised from room temperature to the reduction temperature for 4 hours.

[0020] Preferably, in the step S3, during the reduction, the reduction temperature is 1300-1650 DEG C, the holding time is 20-200 minutes, and the hydrogen flow rate is 100-1500 ml / min.

[0021] Preferably, in the step S4, the grinding and crushing are performed by using a vibration mill or a ball mill, and the sieving is performed by using a 200-400 mesh sieve to obtain the tungsten powder product with uniform particle size.

[0022] Preferably, in the step S5, the hydrochloric acid is a concentrated hydrochloric acid with a mass fraction of 36%, and the reaction time of the sieved product in the hydrochloric acid is 1 hour.

[0023] Preferably, in the step S5, after the filtration, the crude tungsten powder wet material is washed with deionized water to remove the residual hydrochloric acid and nickel ions.

[0024] Preferably, in the step S1, the mass ratio of the tungsten oxide powder to the activated agent nickel oxide powder is (92 g:8 g)-(100 g:0 g).

[0025] The application provides a method for preparing coarse-grained tungsten powder.

[0026] 1. The application adds the activated agent nickel oxide into the tungsten oxide, mixes uniformly, lays into the corundum boat, and reduces by introducing hydrogen into the tube furnace to obtain the tungsten powder and the new activated agent nickel melt, the tungsten powder particles are continuously dissolved and precipitated in the activated agent nickel melt, the tungsten powder particles are continuously grown to form the coarse-grained tungsten powder, the tungsten powder particles are rapidly dissolved in the melt and continuously precipitated on the surface of the tungsten particles, the tungsten powder particles are further grown, the growth rate is fast, the efficiency is high, the coarse-grained tungsten powder is prepared, the process operation is simple, easy to control, and industrialized production can be realized.

[0027] 2、The application guarantees the uniformity of raw material mixing through ball milling, removes oxidation interference through vacuum, realizes complete reduction through hydrogen, and removes residual impurities through concentrated hydrochloric acid, forming a complete quality control chain, achieving the technical effects of high purity, no oxidation layer and impurity residue of coarse particle tungsten powder, compared with the technical solution of single optimization of a step in the prior art, solving the problems of product oxygen content exceeding the standard and high impurity residue due to insufficient process synergy, affecting the subsequent application performance.

[0028] 3、The application adopts the technical solution of vibration milling targeted crushing combined with specific mesh screening, selects the appropriate crushing equipment according to the physical properties of coarse particle tungsten powder, avoids excessive crushing or agglomeration of particles, and achieves the technical effects of good particle integrity and uniform particle size distribution, compared with the technical solution of generally using a ball mill for crushing in the prior art, solving the problems of excessive refinement of coarse particle tungsten powder and particle morphology damage due to excessive grinding intensity, which cannot maintain the characteristics of coarse particles. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 It is a step flow diagram of the method for preparing coarse particle tungsten powder of the application;

[0030] Figure 2 It is an electron microscope graph of Comparative Example 1 of the method for preparing coarse particle tungsten powder of the application;

[0031] Figure 3 It is an electron microscope graph of Example 1 of the method for preparing coarse particle tungsten powder of the application;

[0032] Figure 4 It is an electron microscope graph of Example 2 of the method for preparing coarse particle tungsten powder of the application;

[0033] Figure 5 It is an electron microscope graph of Example 3 of the method for preparing coarse particle tungsten powder of the application. DETAILED DESCRIPTION

[0034] The technical solutions of the application will be described clearly and completely below in combination with the drawings of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the application.

[0035] Please refer to the drawings of the application Figure 1 The embodiment of the application provides a method for preparing coarse particle tungsten powder, including the following steps:

[0036] S1: batching, selecting tungsten oxide powder and activated nickel oxide powder, and batching according to the mass ratio;

[0037] S2: Ball milling, the mixed powder of tungsten oxide powder and activator nickel oxide powder prepared in step S1 is put into a ball milling cylinder, and grinding balls are used for milling to obtain uniformly mixed powder;

[0038] S3: Charging and reducing, the mixed powder after ball milling in step S2 is discharged, and is placed in a boat and laid flat, the boat is placed in a heating furnace, and hydrogen is introduced into the heating furnace for reduction. In the reduction process, tungsten oxide is reduced to tungsten powder, and nickel oxide is reduced to nickel melt. Tungsten powder particles are dissolved in the nickel melt and precipitate on the surface of tungsten particles to achieve particle growth, thereby obtaining a product containing tungsten powder and nickel melt;

[0039] S4: Crushing and sieving, the product after reduction in step S3 is ground and crushed, and then sieved;

[0040] S5: Nickel removal, the sieved product in step S4 is placed in hydrochloric acid for reaction to remove nickel powder from the tungsten powder. After the reaction is completed, filtration is performed to obtain crude tungsten powder wet material;

[0041] S6: Drying and detection, the crude tungsten powder wet material obtained in step S5 is washed with deionized water and then dried. The tungsten powder after drying is detected for Fisher particle size and scanning electron microscope image.

[0042] In step S1, the tungsten oxide powder is yellow tungsten trioxide or blue tungsten oxide, and the particle size of the tungsten oxide powder is 10-28 μm.

[0043] In step S1, the particle size of the activator nickel oxide powder is 1-10 μm, and the mass fraction of the activator nickel oxide is 0-15%.

[0044] In step S2, the ball milling cylinder is a 0.5 liter ball milling cylinder, the grinding balls are alloy balls, the ball-to-material ratio is controlled to be (1-4):1, the ball milling time is 6-20 hours, and the amount of alloy balls is 100g-400g.

[0045] In step S3, the boat is a corundum boat, and the heating furnace is a tube furnace. Before hydrogen is introduced, the tube furnace is subjected to vacuum treatment, and the temperature rising time from room temperature to the reduction temperature is 4 hours.

[0046] In step S3, during the reduction process, the reduction temperature is 1300-1650℃, the holding time is 20-200 minutes, and the hydrogen flow rate is 100-1500 ml / min.

[0047] In step S4, the grinding and crushing are performed using a vibration mill or a ball mill, and a 200-400 mesh sieve is used for sieving to obtain tungsten powder products with uniform particle size.

[0048] In step S5, the hydrochloric acid is concentrated hydrochloric acid with a mass fraction of 36%, and the reaction time of the sieved product in the hydrochloric acid is 1 hour.

[0049] In step S5, the wet rough tungsten powder is washed with deionized water to remove residual hydrochloric acid and nickel ions.

[0050] In step S6, the mass ratio of the tungsten oxide powder to the activating agent nickel oxide powder in step S1 is (92g-8g):(100g-0g).

[0051] The following will be described in combination with specific examples:

[0052] Example 1

[0053] Please refer to the attached Figure 3 A method for preparing rough granular tungsten powder, comprising the following steps:

[0054] S1: ingredients: select blue tungsten oxide with a particle size of 10 μm, select activating agent nickel oxide powder with a particle size of 1 μm, and the mass fraction of the nickel oxide is 1%, the total mass of the material is 100g, and the weight ratio of the blue tungsten oxide to the nickel oxide powder is 99g:1g;

[0055] S2: ball milling: put into a 0.5L ball mill, use 100g alloy balls, control the ball-to-material ratio to be 1:1, and ball mill for 10 hours to obtain a substantially uniform powder;

[0056] S3: loading and reduction: use a corundum boat to load and lay flat, put into a tube furnace, vacuumize, heat up to 1300℃ for 4 hours, and then introduce hydrogen, and keep the temperature for 20 minutes, in the reduction process, the tungsten oxide and the nickel oxide are completely reacted, and the tungsten powder particles are initially grown;

[0057] S4: crushing and sieving: use a ball mill to grind and crush, and pass through a 200 mesh sieve;

[0058] S5: nickel removal: put into 36% concentrated hydrochloric acid for 1 hour, and then wash twice with deionized water after filtration;

[0059] S6: drying and detection: dry at 80℃ for 2 hours, and detect that the Fisher particle size of the tungsten powder is 26 μm, the scanning electron microscope image shows that the particles have no obvious agglomeration, and the basic requirements of the rough granular tungsten powder are met.

[0060] Example 2

[0061] Please refer to the attached Figure 4 A method for preparing rough granular tungsten powder, comprising the following steps:

[0062] S1: ingredients: select yellow tungsten trioxide with a particle size of 16 μm, select activating agent nickel oxide powder with a particle size of 5 μm, and the mass fraction of the nickel oxide is 5%, and the mass of the tungsten trioxide to the activating agent nickel oxide powder is 95g:5g;

[0063] S2 Ball milling: Put the mixture into a 0.5 liter ball milling cylinder, use 400g alloy balls, control the ball-to-material ratio to be 4:1, and ball mill for 6 hours to obtain a uniform powder without agglomeration;

[0064] S3 Loading and reduction: Put the powder into a corundum boat and lay it flat in a tube furnace, first remove air interference by vacuumizing, then heat up to 1560℃ for 4 hours, and pass in hydrogen, and keep the temperature for 60 minutes. During the reduction process, the tungsten oxide is completely reduced to tungsten powder, the nickel oxide is reduced to a nickel melt, and the tungsten powder particles are uniformly dissolved and precipitated in the nickel melt;

[0065] S4 Crushing and sieving: Use a vibration mill to grind and crush the reduction product, and pass it through a 300 mesh sieve to remove a small amount of large agglomerates;

[0066] S5 Nickel removal: Put the sieved product into 36% concentrated hydrochloric acid, react at room temperature for 1 hour, and the nickel melt is completely dissolved. After filtration, wash with deionized water 3 times to remove residual hydrochloric acid and nickel ions;

[0067] S6 Drying and detection: Put the wet material into a 100℃ drying oven and dry for 3 hours. The detection shows that the tungsten powder has a Fisher particle size of 38μm, the scanning electron microscope image shows that the particle morphology is regular, there are no false particles, and the dispersibility is excellent.

[0068] Example 3

[0069] Please refer to the attached Figure 5 A method for preparing coarse-grained tungsten powder, comprising the following steps:

[0070] S1 Blending: Select yellow tungsten trioxide with a particle size of 28μm, and select activated agent nickel oxide powder with a particle size of 10μm. Blend according to the mass fraction of 8% nickel oxide, and the mass of tungsten trioxide and activated agent nickel oxide powder is 92g:8g;

[0071] S2 Ball milling: Put into a 0.5 liter ball milling cylinder, use 400g alloy balls, control the ball-to-material ratio to be 4:1, and ball mill for 20 hours to obtain a highly uniform powder;

[0072] S3 Loading and reduction: Put the powder into a corundum boat and lay it flat in a tube furnace, first remove air interference by vacuumizing, then heat up to 1560℃ for 4 hours, and pass in hydrogen, and keep the temperature for 60 minutes. During the reduction process, the tungsten oxide is completely reduced to tungsten powder, the nickel oxide is reduced to a nickel melt, and the tungsten powder particles are uniformly dissolved and precipitated in the nickel melt;

[0073] S4 Crushing and sieving: Use a vibration mill to grind and crush the reduction product, and pass it through a 300 mesh sieve to remove a small amount of large agglomerates;

[0074] S5 Nickel removal: Put the sieved product into 36% concentrated hydrochloric acid, react at room temperature for 1 hour, and the nickel melt is completely dissolved. After filtration, wash with deionized water 3 times to remove residual hydrochloric acid and nickel ions;

[0075] S6 drying and detection: drying at 120℃ for 4 hours, detection of tungsten powder Fei's particle size 51 μm, scanning electron microscope shows that the particles are complete and have no oxide layer, meeting the application requirements of large particle size coarse tungsten powder.

[0076] Comparative Example 1

[0077] See the attached Figure 2 A method for preparing coarse particle tungsten powder, in S1, no activator nickel oxide powder is added, only 100g of yellow tungsten trioxide is weighed, the above material is placed in a corundum boat and laid flat, the corundum boat is put into a tube furnace, and the remaining steps are the same as in Example 2.

[0078] Table 1:

[0079]

[0080]

[0081] In combination with Examples 1-3 and Comparative Example 1, and in combination with Table 1, it can be seen that the core performance indicators of the coarse particle tungsten powder in the examples are excellent, the Fei's particle size is stably in the coarse particle interval of 26-51 μm, the particle morphology is regular and the dispersibility is good, the nickel residual amount is as low as 0.006%-0.008%, and the oxygen content is controlled in the range of 0.04%-0.06%; among them, the Fei's particle size of Example 1 is 26 μm, the nickel residual amount is 0.008%, and the oxygen content is 0.06%; the Fei's particle size of Example 2 is 38 μm, the nickel residual amount is 0.007%, and the oxygen content is 0.05%; the Fei's particle size of Example 3 is 51 μm, the nickel residual amount is 0.006%, and the oxygen content is 0.04%; all the indicators are much better than those of the comparative example.

[0082] From the performance regulation and process synergistic effect, the excellent performance of the coarse particle tungsten powder in the examples is due to the synergistic effect of various key factors:

[0083] The addition of nickel oxide in S1 provides a core dissolution and precipitation carrier for the growth of tungsten powder particles, and the nickel melt generated by the reduction of nickel oxide realizes the directional growth of tungsten powder particles, and the Fei's particle size increases from 26 μm to 51 μm with the increase of the mass fraction of nickel oxide from 1% to 8% in Examples 1-3, which is a direct manifestation of this mechanism;

[0084] S2 ball milling ensures uniform micro-distribution of tungsten oxide and nickel oxide, laying a foundation for the dispersion of nickel melt in the subsequent reduction stage, and Examples 1-3 show good dispersibility and no obvious agglomeration after ball milling;

[0085] The vacuum pretreatment before S3 reduction can exclude the residual air in the furnace and avoid the secondary oxidation of tungsten powder, and in combination with the strong reducing property of hydrogen, the oxygen content of the examples is always less than 0.06%;

[0086] The 36% concentrated hydrochloric acid in S5 can completely dissolve the nickel melt, ensuring that the residual amount of nickel in the example is less than 0.01%;

[0087] The cooperation of the process parameters of each step and the types of substances forms a complete synergistic chain, and finally realizes the high-quality preparation of coarse-grained tungsten powder.

[0088] In the comparative example 1, because the activating agent nickel oxide is not added, the tungsten powder cannot effectively grow up due to the lack of the nickel melt carrier required for the growth of the tungsten powder particles, the Fisher particle size is only 15.5 μm, the residual amount of nickel is 0.000%, and the oxygen content is 0.07%.

[0089] In conclusion, the mutual cooperation of the key factors such as the addition ratio of the nickel oxide in S1, the ball milling process parameters in S2, the cooperation of the vacuum pretreatment and hydrogen reduction in S3, the vibration milling crushing mode in S4, and the concentrated hydrochloric acid nickel removal conditions in S5 not only realizes the accurate regulation of the tungsten powder particle size in the range of 26-51 μm, but also guarantees the high-quality performance of the particle dispersity, low nickel residual amount and low oxygen content, which is significantly superior to the comparison of the single factor loss or improper process parameters, fully proving the rationality and synergistic advantages of the process of the present application.

[0090] Although the embodiments of the present application have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A method for preparing coarse-grained tungsten powder, characterized in that, Includes the following steps: S1: Ingredients: Select tungsten oxide powder and activator nickel oxide powder, and mix them according to the mass ratio; S2: Ball milling: The mixture of tungsten oxide powder and activator nickel oxide powder prepared in step S1 is placed into a ball mill cylinder and ground with grinding balls to obtain a uniformly mixed powder. S3: Loading and reduction: The mixed powder after ball milling in step S2 is unloaded, placed in a boat and spread evenly, and the boat is placed in a heating furnace. Hydrogen gas is introduced into the heating furnace for reduction. During the reduction process, tungsten oxide is reduced to tungsten powder, and nickel oxide is reduced to nickel melt. Tungsten powder particles dissolve in nickel melt and precipitate on the surface of tungsten particles to achieve particle growth, resulting in a product containing tungsten powder and nickel melt. S4: Crushing and sieving: Grind and crush the product reduced in step S3, and then sieve it. S5: Remove nickel. The product sieved in step S4 is placed in hydrochloric acid to react and remove nickel powder from the tungsten powder. After the reaction is complete, it is filtered to obtain coarse tungsten powder wet material. S6: Drying and testing. The coarse tungsten powder wet material obtained in step S5 is washed with deionized water and then dried. The Fisher particle size and scanning electron microscope image of the dried tungsten powder are then tested.

2. The method for preparing coarse-grained tungsten powder according to claim 1, characterized in that: In step S1, the tungsten oxide powder is yellow tungsten trioxide or blue tungsten oxide, and the particle size of the tungsten oxide powder is 10-28 μm.

3. The method for preparing coarse-grained tungsten powder according to claim 1, characterized in that: In step S1, the particle size of the activator nickel oxide powder is 1-10 μm, and the mass fraction of the activator nickel oxide is 1-15%.

4. The method for preparing coarse-grained tungsten powder according to claim 1, characterized in that: In step S2, the ball mill is a 0.5-liter ball mill, the grinding balls are alloy balls, the ball-to-material ratio is controlled at (1-4):1, the ball milling time is 6-20 hours, and the amount of alloy balls used is 100g-400g.

5. The method for preparing coarse-grained tungsten powder according to claim 1, characterized in that: In step S3, the boat is a corundum boat, and the heating furnace is a tube furnace. Before introducing hydrogen, the tube furnace is evacuated, and the heating time from room temperature to reduction temperature is 4 hours.

6. The method for preparing coarse-grained tungsten powder according to claim 1, characterized in that: In step S3, during the reduction process, the reduction temperature is 1300-1650℃, the holding time is 20-200 minutes, and the hydrogen flow rate is 100-1500 ml / min.

7. The method for preparing coarse-grained tungsten powder according to claim 1, characterized in that: In step S4, grinding and crushing are carried out using a vibratory mill or a ball mill, and sieving is done using a 200-400 mesh sieve to obtain tungsten powder products with uniform particle size.

8. The method for preparing coarse-grained tungsten powder according to claim 1, characterized in that: In step S5, the hydrochloric acid is concentrated hydrochloric acid with a mass fraction of 36%, and the reaction time of the sieved product in hydrochloric acid is 1 hour.

9. The method for preparing coarse-grained tungsten powder according to claim 1, characterized in that: In step S5, the wet coarse tungsten powder is washed with deionized water after filtration to remove residual hydrochloric acid and nickel ions.

10. The method for preparing coarse-grained tungsten powder according to claim 1, characterized in that: In step S1, the mass ratio of tungsten oxide powder to activator nickel oxide powder is (92g:8g)-(100g:0g).

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