A method for recovering tungsten and tungsten alloy from tungsten-containing waste materials

Abstract

The present invention relates to the technical field of nonferrous metal metallurgy, and in particular to a method for recovering tungsten and tungsten alloys from tungsten-containing waste materials. The recovery method provided by the present invention comprises the following steps: plasma melting a clean tungsten-containing profile in an atmospheric environment, water quenching the molten liquid to obtain water-quenched tungsten-containing particles; primary crushing the water-quenched tungsten-containing particles to obtain crushed tungsten-containing particles; oxidation treatment of the crushed tungsten-containing particles to obtain oxide particles; sequentially air-jet milling and screening of the oxide particles to obtain screened powders; reduction treatment of the screened powder to obtain tungsten powder and / or tungsten alloy powder. The recovery method provided by the present invention can meet the requirements of efficient recovery of various types of tungsten raw materials, and can prepare high-quality tungsten and tungsten alloy powders with good surface morphology and controllable particle size, which can be directly used for the preparation of high-performance alloys to achieve resource recycling.

Description

Technical Field

[0001] The invention relates to the technical field of nonferrous metal metallurgy, and in particular to a method for recovering tungsten and tungsten alloys from tungsten-containing waste materials. Background Art

[0002] Tungsten alloys are widely used in aerospace, metallurgical machinery, mining, automotive industry and other industries, and have an important strategic position. With the rapid development of the world economy and science and technology, the demand for tungsten alloys continues to increase. However, as a non-renewable resource, tungsten's storage capacity is reduced due to continuous development and utilization. Therefore, in view of the current situation of tungsten resource shortage, developing an economical, efficient and environmentally friendly method to recycle tungsten and tungsten alloy materials is of great significance to social and economic benefits and ecological benefits.

[0003] At present, the commonly used methods for recycling tungsten or tungsten alloy materials are chemical recovery method and redox method. The process of chemical recovery method is mainly to treat tungsten waste slag into tungsten salt by acid leaching or high-temperature alkali melting, and then remove impurities and roast the obtained tungsten salt to obtain tungsten powder. However, this method requires a large amount of chemical reagents, which is easy to cause environmental pollution and high cost. It is only suitable for the recovery of tungsten waste slag. The process flow of redox method is usually: tungsten material-pretreatment-oxidation-crushing-reduction. Compared with the chemical recovery method, the redox method has a short process flow, is economical and reliable, and can achieve more efficient recovery of tungsten waste.

[0004] Chinese patent CN 117025984 A discloses a method for recycling tungsten alloy scraps, which includes reducing, ball milling and screening the tungsten alloy scraps. This method is only applicable to tungsten alloy scraps, and the tungsten alloy powder obtained can only meet the production performance requirements of products with low purity.

[0005] Chinese patent CN 103114204 A discloses a method for recycling tungsten-based alloy waste. The process flow is: tungsten-based alloy waste cleaning, crushing, oxidation, and reduction. This method has a high waste utilization rate, and the obtained tungsten alloy powder can be directly used to produce high-performance tungsten alloys. However, this method has low adaptability to raw materials. For various tungsten materials such as tungsten rods and tungsten twisted wires, the above process is difficult to achieve efficient recovery. Summary of the invention

[0006] In order to solve the problems existing in the prior art, the present invention provides a method for recovering tungsten and tungsten alloys from tungsten-containing waste materials. The recovery method provided by the present invention can achieve efficient recovery of various tungsten-containing materials.

[0007] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0008] The present invention provides a method for recovering tungsten and tungsten alloys from tungsten-containing waste materials, comprising the following steps:

[0009] The clean tungsten-containing profile is plasma melted in an atmospheric environment, and the molten liquid is water quenched to obtain water-quenched tungsten-containing particles;

[0010] The water-quenched tungsten-containing particles are preliminarily crushed to obtain crushed tungsten-containing particles;

[0011] The crushed tungsten-containing particles are oxidized to obtain oxide particles;

[0012] The oxide particles are subjected to jet milling and sieving in sequence to obtain sieved powder;

[0013] The sieved powder is subjected to reduction treatment to obtain tungsten powder and / or tungsten alloy powder.

[0014] Preferably, when the tungsten-containing waste material is a tungsten-containing wire material or a tungsten-containing wire material, before plasma melting, the tungsten-containing wire material or the tungsten-containing wire material is subjected to a profiling treatment to obtain a tungsten-containing profile;

[0015] When the tungsten-containing waste material is tungsten-containing rods, before plasma melting, the tungsten-containing rods are bundled to obtain tungsten-containing profiles.

[0016] Preferably, the particle size of the tungsten-containing particles after water quenching is 2-5 mm.

[0017] Preferably, the primary crushing method is ball milling; the particle size of the crushed tungsten-containing particles is 20-300 μm.

[0018] Preferably, the temperature of the oxidation treatment is 500-1000° C., and the time of the oxidation treatment is 1-5 hours.

[0019] Preferably, the jet milling treatment is carried out under a nitrogen atmosphere; and the particle size of the powder after screening is less than 75 μm.

[0020] Preferably, the temperature of the reduction treatment is 700-1000° C., and the time of the reduction treatment is 1-5 hours.

[0021] Preferably, the method for obtaining the clean tungsten-containing profile is: soaking the tungsten-containing waste material in alkaline solution, washing with water, ultrasonic cleaning and drying in sequence.

[0022] Preferably, the alkali solution is a sodium hydroxide solution; the mass concentration of the sodium hydroxide solution is 5%; and the soaking time of the alkali solution is 10 to 40 seconds.

[0023] Preferably, the drying temperature is 150-300° C., and the drying time is 3-8 min.

[0024] The present invention provides a method for recovering tungsten and tungsten alloys in tungsten-containing waste materials, comprising the following steps: plasma melting clean tungsten-containing profiles under atmospheric conditions, water quenching the melted liquid to obtain water-quenched tungsten-containing particles; primary crushing the water-quenched tungsten-containing particles to obtain crushed tungsten-containing particles; oxidation treatment of the crushed tungsten-containing particles to obtain oxide particles; sequentially airflow milling and screening of the oxide particles to obtain screened powders; reduction treatment of the screened powders to obtain tungsten powder and / or tungsten alloy powder. The present invention uses plasma melting to melt tungsten-containing profiles that require a relatively high temperature to melt, and has the advantages of simple operation, high melting temperature, and fast melting rate. The subsequent water quenching can quickly cool the melted liquid, so that the water-quenched particles have a relatively high brittleness, thereby facilitating subsequent airflow milling and other treatments. In addition, the recovery method provided by the present invention has no chemical pollution, the entire reaction process is green and environmentally friendly, greatly reduces energy loss, and saves industrial production costs. Compared with other traditional recovery technology methods, the plasma melting-oxidation-reduction method can meet the requirements of efficient recovery of various types of tungsten raw materials. The recycling method provided by the present invention can prepare high-quality tungsten and tungsten alloy powders with good surface morphology and controllable particle size, which can be directly used for the preparation of high-performance alloys, thereby realizing the recycling of resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A schematic diagram of the recovery method provided by the present invention;

[0026] Figure 2 This is a picture of the tungsten-containing particles after water quenching in Example 1;

[0027] Figure 3 This is a morphology of the crushed tungsten-containing particles of Example 1;

[0028] Figure 4 This is the powder morphology after screening of Example 1;

[0029] Figure 5 The powder morphology after reduction of Example 1. DETAILED DESCRIPTION

[0030] The present invention provides a method for recovering tungsten and tungsten alloys from tungsten-containing waste materials, comprising the following steps:

[0031] The clean tungsten-containing profile is plasma melted in an atmospheric environment, and the molten liquid is water quenched to obtain water-quenched tungsten-containing particles;

[0032] The water-quenched tungsten-containing particles are preliminarily crushed to obtain crushed tungsten-containing particles;

[0033] The crushed tungsten-containing particles are oxidized to obtain oxide particles;

[0034] The oxide particles are subjected to jet milling and sieving in sequence to obtain sieved powder;

[0035] The sieved powder is subjected to reduction treatment to obtain tungsten powder and / or tungsten alloy powder.

[0036] Figure 1 The schematic diagram of the recovery method provided by the present invention is as follows:

[0037] The invention performs plasma melting on clean tungsten-containing profiles in an atmospheric environment, and water quenches the molten liquid to obtain water-quenched tungsten-containing particles.

[0038] As an implementation mode, the method for obtaining the clean tungsten-containing profile is: soaking the tungsten-containing waste material in alkaline solution, washing with water, ultrasonic cleaning and drying in sequence.

[0039] As an implementation mode, the alkali solution is a sodium hydroxide solution; the mass concentration of the sodium hydroxide solution is 5%; the alkali solution immersion time is 10 to 40 seconds, and in a specific embodiment, the alkali solution immersion time can be 20 to 30 seconds.

[0040] As an implementation mode, the drying temperature is 150-300° C., and the drying time is 3-8 min. In a specific embodiment, the drying temperature may be 200-250° C., and the drying time may be 5 min.

[0041] As an embodiment, when the tungsten-containing waste material is a tungsten-containing wire or a tungsten-containing wire, before plasma melting, the tungsten-containing wire or the tungsten-containing wire is subjected to a profiling process to obtain a tungsten-containing profile.

[0042] As an implementation mode, when the tungsten-containing waste material is tungsten-containing rods, before plasma melting, the tungsten-containing rods are bundled to obtain tungsten-containing profiles.

[0043] As an embodiment, the particle size of the tungsten-containing particles after water quenching is 2-5 mm.

[0044] In the present invention, the water quenching can solidify the molten liquid and make it embrittled.

[0045] After obtaining the water-quenched tungsten-containing particles, the present invention performs primary crushing on the water-quenched tungsten-containing particles to obtain crushed tungsten-containing particles.

[0046] As an implementation mode, the primary crushing method is ball milling; the particle size of the crushed tungsten-containing particles is 20-300 μm.

[0047] After obtaining the crushed tungsten-containing particles, the present invention performs oxidation treatment on the crushed tungsten-containing particles to obtain oxide particles;

[0048] As an embodiment, the temperature of the oxidation treatment is 500-1000°C, and the time of the oxidation treatment is 1-5 hours. In a specific embodiment, the temperature of the oxidation treatment can be 600-800°C, and the time of the oxidation treatment can be 3-4 hours. As an embodiment, the heating rate of heating to the temperature of the oxidation treatment is 10-20°C / min.

[0049] After obtaining the oxide particles, the present invention sequentially performs jet milling and sieving on the oxide particles to obtain sieved powder.

[0050] As an embodiment, the jet milling process is performed under a nitrogen atmosphere. As an embodiment, the particle size of the powder after screening is less than 75 μm. In a specific embodiment, the particle size of the powder after screening can be 10-50 μm.

[0051] After obtaining the sieved powder, the present invention performs a reduction treatment on the sieved powder to obtain tungsten powder and / or tungsten alloy powder.

[0052] As an implementation mode, the temperature of the reduction treatment is 700~1000°C, the time of the reduction treatment is 1~5h, and the heating rate to the temperature of the reduction treatment is 10~20°C / min; in a specific embodiment, the temperature of the reduction treatment can be 800~900°C, the time of the reduction treatment can be 3~4h, and the heating rate can be 15°C / min.

[0053] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0054] Example 1

[0055] The tungsten wire waste (mainly composed of W) was immersed in a 5wt% NaOH solution for 10 seconds, cleaned with pure water and then ultrasonically cleaned, and then dried at 200°C for 3 minutes to obtain clean tungsten wire waste;

[0056] The clean tungsten wire waste is subjected to a pressing process to obtain a strip-shaped tungsten-containing profile;

[0057] Plasma melting of the strip tungsten-containing profile is performed in an atmospheric environment, and a water quenching pool is used at the bottom of the material to receive the molten liquid for water quenching, thereby obtaining water-quenched tungsten-containing particles with a particle size of 2 to 3 mm;

[0058] The water-quenched tungsten-containing particles are ball-milled to obtain crushed tungsten-containing particles with a particle size of 20 to 200 μm;

[0059] The crushed tungsten-containing particles were placed in a high-temperature oxidation furnace for oxidation treatment at 800°C (the heating rate to 800°C was 10°C / min) for 2 hours to obtain oxide particles;

[0060] The oxide particles were jet milled in a nitrogen atmosphere and then sieved using a 200-mesh screen to obtain tungsten oxide powder with a particle size of 10-50 μm.

[0061] The sieved powder was placed in a high-temperature reduction furnace for reduction treatment at a reduction temperature of 700°C (the heating rate to 700°C was 10°C / min) and a reduction time of 2h to obtain tungsten powder.

[0062] Example 2

[0063] The tungsten sheet (mainly composed of WC and Co) was immersed in a 5wt% NaOH solution for 10 seconds, cleaned with pure water and then ultrasonically cleaned, and then dried at 200°C for 3 minutes to obtain a clean tungsten sheet;

[0064] The clean tungsten sheet is plasma melted in the atmosphere, and a water quenching pool is used at the bottom of the material to receive the molten liquid for water quenching to obtain tungsten-containing particles with a particle size of 4-5 mm after water quenching;

[0065] The water-quenched tungsten-containing particles are ball-milled to obtain crushed tungsten-containing particles with a particle size of 50 to 200 μm;

[0066] The crushed tungsten-containing particles were placed in a high-temperature oxidation furnace for oxidation treatment at 800°C (the heating rate to 800°C was 10°C / min) for 2 hours to obtain oxide particles;

[0067] The oxide particles were jet-milled in a nitrogen atmosphere and sieved using a 200-mesh screen to obtain tungsten oxide powder with a particle size of 20 to 50 μm.

[0068] The sieved powder was placed in a high-temperature reduction furnace for reduction treatment at a reduction temperature of 700°C (the heating rate to 700°C was 10°C / min) and a reduction time of 2h to obtain tungsten and tungsten steel alloy powders.

[0069] Example 3

[0070] The tungsten rod (mainly composed of W, Mo, Ni, and Fe) was immersed in a 5wt% NaOH solution for 10 seconds, cleaned with pure water and then ultrasonically cleaned, and then dried at 200°C for 3 minutes to obtain a clean tungsten rod;

[0071] Bundle the clean tungsten rods to obtain tungsten rod profiles;

[0072] The clean tungsten rod profile is plasma melted in the atmosphere, and a water quenching pool is used at the bottom of the material to receive the molten liquid for water quenching to obtain water-quenched tungsten-containing particles with a particle size of 2~4mm;

[0073] The water-quenched tungsten-containing particles are ball-milled to obtain crushed tungsten-containing particles with a particle size of 20 to 200 μm;

[0074] The crushed tungsten-containing particles were placed in a high-temperature oxidation furnace for oxidation treatment at 800°C (the heating rate to 800°C was 10°C / min) for 2 hours to obtain oxide particles;

[0075] The oxide particles were jet-milled in a nitrogen atmosphere and sieved using a 200-mesh screen to obtain tungsten oxide powder with a particle size of 20 to 50 μm.

[0076] The sieved powder was placed in a high-temperature reduction furnace for reduction treatment at a reduction temperature of 700°C (the heating rate to 700°C was 10°C / min) and a reduction time of 2h to obtain tungsten and tungsten-molybdenum alloy.

[0077] Figure 2 The tungsten-containing particles after water quenching in Example 1 are shown in FIG. Figure 2 It can be seen that the particle size of tungsten-containing particles after water quenching is 2~5mm.

[0078] Figure 3 The morphology of the crushed tungsten-containing particles in Example 1 is shown in FIG. Figure 3 It can be seen that the particle size of the tungsten-containing particles after crushing is 20~200μm.

[0079] Figure 4 The powder morphology after screening of Example 1 is shown in FIG. Figure 4 It can be seen that the particle size of the powder after screening is 10~50μm.

[0080] Figure 5 The powder morphology after reduction of Example 1 is shown in FIG. Figure 5 It can be seen that the particle size of the powder after reduction is relatively uniform, about 10μm.

[0081] Although the above embodiment describes the present invention in detail, it is only a part of the embodiments of the present invention, not all of the embodiments. Other embodiments can be obtained based on this embodiment without creativity, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A method for recovering tungsten and tungsten alloys from tungsten-containing waste materials, characterized in that: The steps are: The tungsten wire waste is placed in a 5wt% NaOH solution and soaked for 10 seconds, washed with pure water and then ultrasonically cleaned, and then dried at 200°C for 3 minutes to obtain clean tungsten wire waste; the main component of the tungsten wire waste is W; The clean tungsten wire waste is subjected to a pressing process to obtain a strip-shaped tungsten-containing profile; Plasma melting of the strip tungsten-containing profile is performed in an atmospheric environment, and a water quenching pool is used at the bottom of the material to receive the molten liquid for water quenching, thereby obtaining water-quenched tungsten-containing particles with a particle size of 2 to 3 mm; The water-quenched tungsten-containing particles are ball-milled to obtain crushed tungsten-containing particles with a particle size of 20 to 200 μm; The crushed tungsten-containing particles were placed in a high-temperature oxidation furnace at 800°C, and the heating rate to 800°C was 10°C / min, and the oxidation treatment was performed for 2 hours to obtain oxide particles; The oxide particles were jet-milled in a nitrogen atmosphere and then sieved using a 200-mesh screen to obtain tungsten oxide powder with a particle size of 10 to 50 μm. The sieved powder was placed in a high-temperature reduction furnace for reduction treatment. The reduction temperature was 700°C, the heating rate to 700°C was 10°C / min, and the reduction time was 2h to obtain tungsten powder.

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