A method for producing fine tungsten powder from dust generated in a rotary furnace for producing tungsten powder

Abstract

The present application relates to the field of powder metallurgy, in particular to a method for preparing fine tungsten powder using dust collection material generated by a rotary furnace for producing tungsten powder, wherein the dust collection material generated by the rotary furnace for producing tungsten powder and tungsten oxide can be used to stably prepare tungsten powder of the same quality as that prepared by using normal tungsten oxide, and the problem of difficult recovery of the existing dust collection material is solved, the production efficiency is improved, and the production capacity of tungsten powder is greatly improved.

Description

Technical Field

[0001] This invention relates to the field of powder metallurgy technology, specifically to a method for preparing fine-particle tungsten powder using dust collected from a rotary kiln used in tungsten powder production. Background Technology

[0002] Tungsten possesses advantages such as high melting point, good thermal conductivity, strong radiation absorption, excellent high-temperature strength, and good corrosion resistance, making it widely used in various industrial sectors including mining, metallurgy, machinery, construction, transportation, electronics, chemicals, light industry, textiles, military, aerospace, and science and technology. The properties of tungsten powder (such as purity, particle size, and particle size distribution) mainly depend on the reduction equipment and process. Currently, the main equipment for producing tungsten powder includes fourteen-tube reduction furnaces, fifteen-tube reduction furnaces, and rotary kilns. Among these, rotary kilns offer advantages in reducing and preparing fine-particle tungsten powder due to their high output and stable product quality, making them the primary production equipment for fine-particle tungsten powder in recent years. However, due to the characteristics of this equipment, 10-30 wt% of dust is generated during tungsten powder production. The traditional method for handling this dust involves first subjecting it to high-temperature oxidation to obtain tungsten oxide, and then reducing the tungsten oxide at high temperatures to produce tungsten powder. This process is complex and energy-intensive. Summary of the Invention

[0003] To address the technical problems existing in the prior art, the present invention provides a method for preparing fine-particle tungsten powder using dust collected from a rotary kiln used in tungsten powder production.

[0004] According to one aspect of the present invention, the present invention provides the following technical solution:

[0005] A method for preparing fine-particle tungsten powder using dust collected from a rotary kiln used in tungsten powder production includes the following steps:

[0006] S1. Mix the dust collector with tungsten oxide to obtain a mixture of tungsten oxide and dust collector;

[0007] S2. The mixture is subjected to high-temperature reduction under a reducing atmosphere to obtain tungsten powder;

[0008] S3. Sieve the tungsten powder to obtain uniform fine tungsten powder particles.

[0009] The beneficial effects of this invention are as follows:

[0010] This invention provides a method for preparing fine tungsten powder using dust collected from a rotary kiln used in tungsten powder production. By using dust collected from the rotary kiln and tungsten oxide, tungsten powder of the same quality as that prepared using normal tungsten oxide can be stably produced. Moreover, this method solves the problem of difficult dust collection and recovery, improves production efficiency, and significantly increases the production capacity of tungsten powder. Attached Figure Description

[0011] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0012] Figure 1 Electron micrograph of the fine-particle tungsten powder prepared in Example 1;

[0013] Figure 2 Electron micrograph of the fine-particle tungsten powder prepared in Example 2;

[0014] Figure 3 Electron micrograph of the fine-particle tungsten powder prepared in Example 3;

[0015] Figure 4 Electron micrograph of the fine-particle tungsten powder prepared in Example 4;

[0016] Figure 5 Electron micrograph of the fine-particle tungsten powder prepared in Comparative Example 1;

[0017] Figure 6 Electron micrograph of the fine-particle tungsten powder prepared in Comparative Example 2;

[0018] Figure 7 Electron micrograph of the fine-particle tungsten powder prepared in Comparative Example 3;

[0019] Figure 8 Electron micrograph of the fine-particle tungsten powder prepared for Comparative Example 4.

[0020] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0021] The technical solutions described below in conjunction with the embodiments will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] According to one aspect of the present invention, the present invention provides the following technical solution:

[0023] A method for preparing fine-particle tungsten powder using dust collected from a rotary kiln used in tungsten powder production includes the following steps:

[0024] S1. Mix the dust collection material with tungsten oxide (tungsten oxide used in normal production) to obtain a mixture of tungsten oxide and dust collection material;

[0025] S2. The mixture is subjected to high-temperature reduction under a reducing atmosphere to obtain tungsten powder;

[0026] S3. Sieve the tungsten powder to obtain uniform fine tungsten powder particles.

[0027] Preferably, in step S1, the dust collection material includes tungsten trioxide, intermediate tungsten oxide, and unreacted tungsten powder.

[0028] Preferably, in step S1, the mass ratio of dust to tungsten oxide is 1:(3~5). Specifically, the mass ratio of dust to tungsten oxide can be any one of, for example, 1:3, 1:3.5, 1:4, 1:4.5, 1:5, or any range between two of them.

[0029] Preferably, in step S1, a double-cone mixer is used for mixing, with a mixing time of 30-60 minutes and a mixing speed of 6.0-10.0 r / min. Specifically, the mixing time can be any one or a range between any two of, for example, 30 minutes, 35 minutes, 40 minutes, 45 minutes, 50 minutes, 55 minutes, and 60 minutes. The mixing speed can be any one or a range between any two of, for example, 6.0 r / min, 7.0 r / min, 8.0 r / min, 9.0 r / min, and 10.0 r / min.

[0030] Preferably, in step S2, the reduction process is carried out in a rotary kiln, with the feed rate of the mixture being 100~280 kg / h, the reduction temperature being 610~1020℃, and the reducing atmosphere flow rate being 400~550 m³ / h. 3 The rotary kiln rotates at a speed of 3-6 r / min, and the reducing atmosphere is hydrogen. Specifically, the feed rate of the mixture during the reduction process can be any one or a range between any two of the following: 100 kg / h, 110 kg / h, 120 kg / h, 130 kg / h, 140 kg / h, 150 kg / h, 160 kg / h, 170 kg / h, 180 kg / h, 190 kg / h, 200 kg / h, 210 kg / h, 220 kg / h, 230 kg / h, 240 kg / h, 250 kg / h, 260 kg / h, 270 kg / h, 280 kg / h. The reduction temperature can be any one or a range between any two of the following: 610℃, 650℃, 700℃, 750℃, 800℃, 850℃, 900℃, 950℃, 1000℃, 1020℃. The reducing atmosphere flow rate can be, for example, 400 m³ / h. 3 / h、410m 3 / h、420m 3 / h、430m 3 / h、440m 3 / h, 450m 3 / h、460m 3 / h、470m 3 / h、480m 3 / h、490m 3 / h, 500m 3 / h, 510m 3 / h、520m 3 / h、530m 3 / h、540m 3 / h, 550m 3 The rotational speed of the rotary kiln can be any one or a range between any two of the following values: / h. For example, 3 r / min, 4 r / min, 5 r / min, 6 r / min.

[0031] Preferably, in step S2, the rotary kiln includes six temperature zones with progressively increasing temperatures from the feed point to the discharge point.

[0032] Preferably, in step S3, the screen mesh size is 80-100 mesh and the screening machine frequency is 30-50Hz.

[0033] Preferably, in step S3, the tungsten powder in its ground state FSSS has a particle size of 0.70~1.0μm and a specific surface area of ​​2~4㎡ / g.

[0034] The technical solution of the present invention will be further described below with reference to specific embodiments.

[0035] Example 1

[0036] A method for preparing fine-particle tungsten powder using dust collected from a rotary kiln used in tungsten powder production includes the following steps:

[0037] S1. Mix 2t of dust collection material and 6t of tungsten oxide using a double cone mixer for 60 minutes at a mixing speed of 6.0 r / min to obtain a mixture of tungsten oxide and dust collection material.

[0038] S2. The mixture is subjected to high-temperature reduction in a reducing atmosphere to obtain tungsten powder. The reduction process is carried out in a rotary kiln. The feed rate of the mixture during the reduction process is 110 kg / h, and the reduction temperatures are: 610℃ for zone 1, 650℃ for zone 2, 700℃ for zone 3, 750℃ for zone 4, 850℃ for zone 5, and 920℃ for zone 6. The flow rate of the reducing atmosphere is 550 m³ / h. 3 / h, the rotary kiln speed is 5r / min, and the reducing atmosphere is hydrogen;

[0039] S3. Pass the tungsten powder through an 80-mesh linear sieve to obtain uniform, fine-particle tungsten powder, such as... Figure 1 As shown, the specific surface area (BET) of tungsten powder is 3.5 ± 0.5 m² / g.

[0040] Example 2

[0041] A method for preparing fine-particle tungsten powder using dust collected from a rotary kiln used in tungsten powder production includes the following steps:

[0042] S1. Mix 1.5t of dust collection material and 6t of tungsten oxide using a double cone mixer for 60 minutes at a mixing speed of 10.0 r / min to obtain a mixture of tungsten oxide and dust collection material;

[0043] S2. The mixture is subjected to high-temperature reduction in a reducing atmosphere to obtain tungsten powder. The reduction process is carried out in a rotary kiln. The feed rate of the mixture during the reduction process is 129.5 kg / h, and the reduction temperatures are: 590℃ for the first zone, 650℃ for the second zone, 690℃ for the third zone, 750℃ for the fourth zone, 860℃ for the fifth zone, and 940℃ for the sixth zone. The flow rate of the reducing atmosphere is 530 m³ / h. 3 / h, the rotary kiln speed is 5r / min, and the reducing atmosphere is hydrogen;

[0044] S3. Pass the tungsten powder through an 80-mesh linear sieve to obtain uniform, fine-particle tungsten powder, such as... Figure 2 As shown, the specific surface area (BET) of tungsten powder is 2.5 ± 0.5 m² / g.

[0045] Example 3

[0046] A method for preparing fine-particle tungsten powder using dust collected from a rotary kiln used in tungsten powder production includes the following steps:

[0047] S1. Mix 1.5t of dust collection material and 6t of tungsten oxide using a double cone mixer for 60 minutes at a mixing speed of 8.0 r / min to obtain a mixture of tungsten oxide and dust collection material.

[0048] S2. The mixture is subjected to high-temperature reduction in a reducing atmosphere to obtain tungsten powder. The reduction process is carried out in a rotary kiln. The feed rate of the mixture during the reduction process is 230 kg / h, and the reduction temperatures are: 750℃ for the first zone, 830℃ for the second zone, 900℃ for the third zone, 910℃ for the fourth zone, 930℃ for the fifth zone, and 950℃ for the sixth zone. The flow rate of the reducing atmosphere is 500 m³ / h. 3 The rotary kiln speed is 5 r / min, and the reducing atmosphere is hydrogen; the FSSS particle size of the ground tungsten powder is 0.80±0.05μm.

[0049] S3. Pass the tungsten powder through an 80-mesh linear sieve to obtain uniform, fine-particle tungsten powder, such as... Figure 3 As shown.

[0050] Example 4

[0051] A method for preparing fine-particle tungsten powder using dust collected from a rotary kiln used in tungsten powder production includes the following steps:

[0052] S1. Mix 1.2t of dust collection material and 6t of tungsten oxide using a double cone mixer for 60 minutes at a mixing speed of 8.0 r / min to obtain a mixture of tungsten oxide and dust collection material.

[0053] S2. The mixture is subjected to high-temperature reduction in a reducing atmosphere to obtain tungsten powder. The reduction process is carried out in a rotary kiln. The feed rate of the mixture during the reduction process is 260 kg / h, and the reduction temperatures are: 770℃ for zone 1, 850℃ for zone 2, 920℃ for zone 3, 930℃ for zone 4, 950℃ for zone 5, and 970℃ for zone 6. The flow rate of the reducing atmosphere is 480 m³ / h. 3 / h, the rotary kiln speed is 4r / min, and the reducing atmosphere is hydrogen;

[0054] S3. Pass the tungsten powder through an 80-mesh linear sieve to obtain uniform, fine-particle tungsten powder, such as... Figure 4 As shown, the particle size of the ground FSSS tungsten powder is 0.90±0.05μm.

[0055] Comparative Example 1

[0056] 8 tons of tungsten oxide were reduced at high temperature in a reducing atmosphere to obtain tungsten powder. The reduction process was carried out in a rotary kiln. The feed rate of the mixture was 110 kg / h, and the reduction temperatures were: 630℃ for zone 1, 700℃ for zone 2, 750℃ for zone 3, 800℃ for zone 4, 900℃ for zone 5, and 970℃ for zone 6. The flow rate of the reducing atmosphere was 550 m³ / h. 3 The rotary kiln rotates at 5 r / min, and the reducing atmosphere is hydrogen. The tungsten powder is passed through an 80-mesh linear sieve to obtain uniform fine tungsten powder with a specific surface area (BET) of 3.5 ± 0.5 m² / g.

[0057] The tungsten powder produced in this comparative example is as follows: Figure 5 As shown, the tungsten powder produced in Comparative Example 1 has no difference in physical properties and microstructure compared to that produced in Example 1. However, the reduction temperature of Comparative Example 1 is higher than that of Example 1.

[0058] Comparative Example 2

[0059] 7.5 tons of tungsten oxide were reduced at high temperature in a reducing atmosphere to obtain tungsten powder. The reduction process was carried out in a rotary kiln. The feed rate of the mixture during the reduction process was 129.5 kg / h, and the reduction temperatures were: 640℃ for the first zone, 700℃ for the second zone, 740℃ for the third zone, 800℃ for the fourth zone, 910℃ for the fifth zone, and 990℃ for the sixth zone. The flow rate of the reducing atmosphere was 530 m³ / h. 3 The rotary kiln rotates at 5 r / min, and the reducing atmosphere is hydrogen. The tungsten powder is passed through an 80-mesh linear sieve to obtain uniform fine tungsten powder with a specific surface area (BET) of 2.5 ± 0.5 m² / g.

[0060] The tungsten powder produced in this comparative example is as follows: Figure 6 As shown, the tungsten powder produced in Comparative Example 2 has no difference in physical properties and microstructure compared to that produced in Example 2. However, the reduction temperature of Comparative Example 2 is higher than that of Example 2.

[0061] Comparative Example 3

[0062] 7.5 tons of tungsten oxide were reduced at high temperature in a reducing atmosphere to obtain tungsten powder. The reduction process was carried out in a rotary kiln. The feed rate of the mixture was 230 kg / h, and the reduction temperatures were: 640℃ for the first zone, 700℃ for the second zone, 740℃ for the third zone, 800℃ for the fourth zone, 910℃ for the fifth zone, and 990℃ for the sixth zone. The flow rate of the reducing atmosphere was 500 m³ / h. 3 The rotary kiln rotates at 5 r / min, and the reducing atmosphere is hydrogen. The tungsten powder is passed through an 80-mesh linear sieve to obtain uniform fine tungsten powder. The particle size of the ground FSSS tungsten powder is 0.80±0.05μm.

[0063] The tungsten powder produced in this comparative example is as follows: Figure 7 As shown, the tungsten powder produced in Comparative Example 3 showed no difference in physical properties and microstructure compared to that produced in Example 3. However, the reduction temperature of Comparative Example 3 was higher than that of Example 3.

[0064] Comparative Example 4

[0065] 7.2 tons of tungsten oxide were reduced at high temperature in a reducing atmosphere to obtain tungsten powder. The reduction process was carried out in a rotary kiln. The feed rate of the mixture during the reduction process was 260 kg / h, and the reduction temperatures were: 800℃ for the first zone, 880℃ for the second zone, 950℃ for the third zone, 960℃ for the fourth zone, 980℃ for the fifth zone, and 1000℃ for the sixth zone. The flow rate of the reducing atmosphere was 480 m³ / h. 3 The rotary kiln rotates at 4 r / min, and the reducing atmosphere is hydrogen. The tungsten powder is passed through an 80-mesh linear sieve to obtain uniform fine tungsten powder. The particle size of the ground FSSS tungsten powder is 0.90±0.05μm.

[0066] The tungsten powder produced in this comparative example is as follows: Figure 8 As shown, the tungsten powder produced in Comparative Example 4 showed no difference in physical properties and microstructure compared to that produced in Example 4. However, the reduction temperature of Comparative Example 4 was higher than that of Example 4.

[0067] Comparative Example 5

[0068] 4 tons of dust collector material and 2 tons of tungsten oxide were mixed using a double cone mixer for 30 minutes at a mixing speed of 6.0 r / min to obtain a mixture of tungsten oxide and dust collector material. This mixture was then subjected to high-temperature reduction in a reducing atmosphere to obtain tungsten powder. The reduction process was carried out in a rotary kiln. The feed rate of the mixture was 230 kg / h, and the reduction temperatures were: 750℃ for zone 1, 830℃ for zone 2, 900℃ for zone 3, 910℃ for zone 4, 930℃ for zone 5, and 950℃ for zone 6. The reducing atmosphere flow rate was 500 m³ / h. 3 The rotary kiln rotates at 5 r / min, and the reducing atmosphere is hydrogen. The product is passed through an 80-mesh linear sieve to obtain a mixture of brownish-red powder and black powder. XRD analysis shows that the mixture is tungsten dioxide and tungsten powder.

[0069] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A method for producing fine tungsten powder using dust generated in a rotary furnace for producing tungsten powder, characterized by, It comprises the following steps: S1, mixing the dust collection material with tungsten oxide to obtain a mixture of tungsten oxide and dust collection material; the mass ratio of the dust collection material to the tungsten oxide is 1:(3-5); the dust collection material comprises tungsten trioxide, intermediate tungsten oxide and unreacted tungsten powder; S2, high-temperature reduction of the mixture under a reducing atmosphere to obtain tungsten powder; the reduction process is carried out in a rotary furnace, the rotary furnace comprises six temperature zones with increasing temperature from the feeding end to the discharging end; the feeding speed of the mixture in the reduction process is 210-280 kg / h, the reduction temperature is 610-1020 DEG C, the flow rate of the reducing atmosphere is 460-550 m 3 / h, and the reducing atmosphere is hydrogen; S3, sieving the tungsten powder to obtain uniform fine tungsten powder; Stable preparation of tungsten powder of the same quality as that prepared using normal tungsten oxide, with a ground state FSSS particle size of 0.70-1.0 μm and a specific surface area of 2-4 m 2 / g.

2. The method of claim 1 for producing fine tungsten powder from dust generated in a rotary furnace for producing tungsten powder, characterized by, In the step S1, a double-cone mixer is used for mixing, the mixing time is 30-60 min, and the mixing speed is 6.0-10.0 r / min.

3. The method of claim 1, wherein the fine tungsten powder is prepared from the dust generated in the rotary furnace for producing tungsten powder. In the step S2, the rotating speed of the rotary furnace is 3-6 r / min.

4. The method of claim 1 for producing fine tungsten powder from dust generated in a rotary furnace for producing tungsten powder, characterized by, In the step S3, the mesh number of the screen is 80-100 meshes, and the screen frequency is 30-50 Hz.

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