Preparation method and system of nano metal oxide powder

Abstract

The present invention provides a method for preparing nano metal oxide powder, wherein the plasma generated by a plasma gun is used to heat a solid mixture in a gasification furnace body, and the obtained gaseous material undergoes an oxidation reaction with air to obtain metal oxide, and the metal oxide enters a material receiving system driven by air and is rapidly cooled to obtain nano metal oxide powder; in the process of heating and gasifying the solid mixture by the plasma gun, the solid mixture is transported into the furnace to maintain the material layer height in the furnace at a set height of ±2 cm; and an excitation winding is provided on the circumference of the plasma furnace, and an alternating current is passed into the excitation winding in the process of heating and gasifying the solid mixture by the plasma gun, and the generated alternating magnetic field expands the size of the plasma in the horizontal direction. The preparation method has a wide source of materials, is easy to implement, is environmentally friendly, does not generate wastewater, can be used for large-scale production, and can prepare metal oxide powder for ceramic targets with small powder particle size, good particle uniformity, high purity, and no agglomeration.

Description

Technical Field

[0001] The invention belongs to the technical field of nano powder preparation, and relates to a method and a system for preparing nano metal oxide powder, and in particular to a method and a system for preparing nano metal oxide powder for ceramic targets. Background Art

[0002] Oxide ceramic targets are a type of material widely used in a variety of fields, mainly in industries such as liquid crystal panels, touch screens, thin-film solar cells, and light-emitting diodes. Specifically, oxide ceramic targets include indium tin oxide (ITO) targets, indium gallium zinc oxide (IGZO) targets, and aluminum zinc oxide powder (AZO) targets. Oxide ceramic targets are made into thin films by magnetron sputtering, electron beam evaporation, and chemical vapor deposition. These films have the characteristics of high hardness, wear resistance, and good chemical stability, which makes them play an important role in the above-mentioned fields.

[0003] Nano-indium oxide powder and nano-tin oxide powder are the main raw materials for preparing transparent conductive film ITO (indium tin oxide) targets. The powder properties have a significant impact on the quality of the prepared ITO targets. How to prepare high-performance powders has always been a key research topic.

[0004] Wang Zhicheng et al. (patent application: A method for preparing highly dispersed nano-tin oxide powder by microwave method, application number 202311014576.9) disclosed a method for preparing nano-tin oxide powder, which comprises mixing tin chloride with methanol to prepare a tin solution, adding a tin alloy to the tin solution and purifying it to obtain a refined tin product; heating the refined tin product to liquefy it, heating it by electric arc to generate tin oxide vapor, and cooling and crystallizing it to obtain a granular product; putting the granular product into a sodium hydroxide aqueous solution, stirring and mixing it, and continuously heating it by microwave to obtain a sol intermediate; ultrasonically dispersing the sol intermediate, and performing gel drying to remove water to produce nano-tin oxide powder. However, this method has problems such as complex processing flow and high preparation cost. Nano indium oxide powder, nano gallium oxide powder, and nano zinc oxide powder are important raw materials for preparing indium gallium zinc oxide thin films. Wang Kai et al. (patent application: A method for preparing nano indium oxide with a large specific surface area, application number 202011460456.8) disclosed a method for preparing nano indium oxide powder. The method dissolves metallic indium in a dilute acid solution and heats it until it is completely dissolved to obtain a solution with a total indium ion concentration of 2 to 4 mol / L; adds a precipitant to control the reaction temperature to 60 to 80 ° C, and the pH value of the reaction liquid is 6.5 to 7.5; adds a converter to control the pH value of the feed liquid to 9.0 to 10.0, heats to near boiling, and keeps warm for 20 to 40 minutes; adds a neutralizer to control the pH value of the feed liquid to 6.5 to 7.5; finally, after filtering, washing, drying, calcining, decomposing, crushing, and screening, nano indium oxide powder is obtained. The purity of the prepared nano indium oxide exceeds 99.995%, the particle size is less than 70nm, and the specific surface area exceeds 65m 2 / g. However, this method has problems such as complicated processing flow, high preparation cost and large amount of wastewater treatment.

[0005] It is an urgent problem to be solved to prepare nano-oxide powder with uniform particle size, excellent performance and high purity by using a simple process, no wastewater generation and low cost. Summary of the invention

[0006] In response to the above technical problems, the present application provides a method and system for preparing nano metal oxide powder for ceramic targets.

[0007] To achieve the above objectives, this application proposes the following technical solutions: In a first aspect, a method for preparing nano metal oxide powder is provided by using a plasma furnace, wherein the plasma furnace is provided with a plasma gun, and the plasma gun is provided above a solid mixture layer in the plasma furnace, and the preparation method comprises: The plasma generated by the plasma gun heats the solid mixture in the gasification furnace to obtain gaseous materials. During the gasification process, air enters the furnace, and the gaseous materials and air undergo oxidation reactions to obtain metal oxides. The metal oxides enter the material collection system driven by the air and are quickly cooled to obtain nano metal oxide powders. The solid mixture is one or more of metal oxides, metals, and alloys. During the process of heating and gasifying the solid mixture by the plasma gun, the solid mixture is transported into the furnace to maintain the material layer height of the solid mixture in the furnace at a set material layer height of ±2 cm; and an excitation winding is provided on the circumference of the plasma furnace. During the process of heating and gasifying the solid mixture by the plasma gun, an alternating current is passed through the excitation winding, and the generated alternating magnetic field expands the size of the plasma in the horizontal direction.

[0008] Furthermore, the air inlet flow rate is 5000~10000m3 / h.

[0009] Furthermore, the plasma furnace is provided with an air inlet; the air inlet is located between the plasma gun and the solid mixture layer.

[0010] Furthermore, an exhaust fan is provided downstream of the plasma furnace, and an air inlet of the exhaust fan is connected to an air outlet of the plasma furnace; the air enters the furnace through the exhaust effect of the exhaust fan.

[0011] Furthermore, the gas outlet of the plasma furnace is located at the upper part of the plasma furnace.

[0012] Furthermore, the solid mixture is one or more of indium gallium zinc oxide waste target material (IGZO), zinc aluminum oxide waste target material (AZO), indium tin oxide waste target material (ITO), gallium zinc oxide waste target material (GZO), antimony tin oxide (ATO) waste target material, indium gallium zinc alloy, zinc aluminum alloy, indium tin alloy, gallium zinc alloy, tin antimony alloy, metal indium, metal tin, metal gallium, metal zinc, metal aluminum, and metal antimony.

[0013] Furthermore, the purity of each component in the solid mixture is independently 4N or above.

[0014] Furthermore, the feeding rate of the solid mixture is 20-150 kg / h, preferably 20-80 kg / h.

[0015] Furthermore, the solid mixture is transported into the furnace body through a screw feeder or a vibrating feeder.

[0016] Furthermore, the particle size of the solid mixture is less than 10 meshes.

[0017] Furthermore, the solid mixture is obtained by crushing the raw materials and then mixing them.

[0018] Furthermore, the power of the plasma gun is 50-100 kW.

[0019] Furthermore, 3 to 4 excitation windings are evenly spaced along the circumference of the furnace body.

[0020] Furthermore, the axial direction of the excitation winding is perpendicular to the axial direction of the plasma furnace.

[0021] Furthermore, the upper surface of the solid mixture layer is between the upper end and the lower end of the excitation winding.

[0022] Furthermore, the operating frequency of the alternating current is 50 Hz, and the alternating current is 10-250A.

[0023] Furthermore, the method further comprises: filtering and cooling the obtained nano metal oxide powder, and collecting the nano metal oxide powder. The filtering accuracy is 0.05-0.1 μm; and the filtering wind speed is 0.1-1 m / min.

[0024] Furthermore, the average particle size of the nano metal oxide powder is 20-100 nm.

[0025] In a second aspect, a system for preparing nano metal oxide powder is provided, comprising: A plasma furnace, wherein the plasma furnace is provided with an air inlet, an air outlet and a feed inlet; A plasma gun, the plasma gun is arranged on the plasma furnace and is located above the solid mixture layer in the plasma furnace; the plasma generated by the plasma gun is used to gasify the solid mixture in the gasification furnace; An air intake assembly, the air intake assembly is communicated with the plasma furnace, and the air intake assembly is used to guide air into the furnace from the air inlet; A feed assembly, the discharge port of the feed assembly is connected to the feed port, and the feed assembly is used to uniformly transport materials into the furnace; A material receiving component, wherein the material inlet of the material receiving component is connected to the gas outlet, and the material receiving component is used to receive and cool the metal oxides generated by the reaction in the furnace and collect nano metal oxide powders; The excitation winding is arranged on the peripheral surface of the plasma furnace. The alternating magnetic field generated by the alternating current flowing through the excitation winding expands the size of the plasma in the horizontal direction.

[0026] Furthermore, the material receiving assembly includes a filter element dust collector, the feed port of the filter element dust collector is connected to the gas outlet, and the filter element dust collector is used to receive, cool and filter the metal oxides in the plasma furnace.

[0027] Furthermore, 3 to 4 excitation windings are evenly spaced along the circumference of the plasma furnace.

[0028] Furthermore, the axial direction of the excitation winding is perpendicular to the axial direction of the plasma furnace.

[0029] Furthermore, the upper surface of the solid mixture layer is between the upper end and the lower end of the excitation winding.

[0030] Compared with the prior art, one or more of the above technical solutions can achieve at least one of the following beneficial effects: The preparation method provided by the present invention has a wide source of materials and can prepare metal oxide powders with small powder size, good particle uniformity, high purity and no agglomeration, such as metal oxide powders for ceramic targets. The preparation method is simple, easy to implement, environmentally friendly, and does not generate wastewater, and can be used for large-scale production. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0032] Figure 1 It is a schematic diagram of the production system of nano metal oxides of the present invention.

[0033] Reference numerals: 1. Crusher; 2. Three-dimensional mixer; 3. Screw feeder; 4. Plasma furnace; 4-1. Furnace body; 4-2. Furnace cover; 5. Plasma gun; 6. Filter element dust collector. DETAILED DESCRIPTION The present invention provides a method for preparing nano metal oxide powder, which is prepared by using a plasma furnace, wherein the plasma furnace is provided with a plasma gun, and the plasma gun is arranged above a solid mixed material layer in the plasma furnace. The preparation method comprises: The plasma generated by the plasma gun heats the solid mixture in the gasification furnace to obtain gaseous materials. During the gasification process, air enters the furnace, and the gaseous materials and air undergo oxidation reactions to obtain metal oxides. The metal oxides enter the material collection system driven by the air and are quickly cooled to obtain nano metal oxide powders. The solid mixture is one or more of metal oxides, metals, and alloys. During the process of heating and gasifying the solid mixture by the plasma gun, the solid mixture is transported into the furnace to maintain the material layer height of the solid mixture in the furnace at a set material layer height of ±2 cm; and an excitation winding is provided on the circumferential surface of the plasma furnace. During the process of heating and gasifying the solid mixture by the plasma gun, an alternating current is passed through the excitation winding, and the generated alternating magnetic field causes the plasma generated by the plasma gun to rotate, that is, the generated alternating magnetic field causes the size of the plasma to expand in the horizontal direction.

[0034] By controlling the particle stacking height in the furnace to remain basically unchanged, the reaction interface can be guaranteed to be smooth and the powder performance can be ensured to be stable; the rotating magnetic field generated by the excitation winding can make the plasma rotate, expand the reaction area, and make the temperature in the furnace uniform, so that the output powder particle size is smaller and the distribution is narrower. The excitation winding can also increase the plasma energy, significantly improving production capacity.

[0035] The plasma gun extends to above the solid mixture layer in the furnace body. Usually, the plasma gun is 5 to 7 cm above the solid mixture layer, which is a conventional distance in the art.

[0036] In some preferred embodiments, the air intake is 5000-10000m 3 / h, for example 5000m 3 / h、5500m 3 / h、6000m 3 / h、6500m 3 / h、7000m 3 / h、7500m 3 / h、8000m 3 / h、8500m 3 / h、9000m 3 / h、9500m 3 / h、10000m 3 / h, etc. The air can be produced by conventional means such as exhaust or blowing in the art.

[0037] In some preferred embodiments, the plasma furnace is provided with an air inlet, and the air inlet is located between the plasma gun and the solid mixture layer. As one of the embodiments, the plasma furnace comprises a furnace body and a furnace cover, and a gap is provided between the furnace body and the furnace cover, and the gap is the air inlet.

[0038] In some preferred embodiments, an exhaust component (such as an exhaust fan) is provided downstream of the plasma furnace, and the air inlet of the exhaust component is connected to the air outlet of the plasma furnace; the air enters the plasma furnace through the exhaust action of the exhaust component. On the one hand, the exhaust can draw the air into the plasma furnace, and on the other hand, it can also bring the metal oxides obtained after oxidation into subsequent processes for further oxidation, as well as cooling and collection of the metal oxides, thereby facilitating the recovery of nano metal oxide products.

[0039] In some preferred embodiments, the solid mixture is one or more of indium gallium zinc oxide waste target material (IGZO), zinc aluminum oxide waste target material (AZO), indium tin oxide waste target material (ITO), gallium zinc oxide waste target material (GZO), antimony tin oxide (ATO) waste target material, indium gallium zinc alloy, zinc aluminum alloy, indium tin alloy, gallium zinc alloy, tin antimony alloy, metal indium, metal tin, metal gallium, metal zinc, metal aluminum, and metal antimony.

[0040] In some preferred embodiments, the purity of each component in the solid mixture is independently 4N or above.

[0041] In some preferred embodiments, the feeding rate of the solid mixture is 20~150kg / h, for example 20kg / h, 30kg / h, 40kg / h, 50kg / h, 60kg / h, 70kg / h, 80kg / h, 90kg / h, 100kg / h, 110kg / h, 120kg / h, 130kg / h, 140kg / h, 150kg / h, etc.

[0042] In some preferred embodiments, the solid mixture is transported to the furnace by a screw feeder or a vibrating feeder or other equipment that can achieve timed and fixed-point feeding. The screw feeder or vibrating feeder is used to quantitatively feed the furnace, and the particle stacking height in the furnace remains basically unchanged, ensuring a stable reaction interface, ensuring the stability of powder performance, and being simple and easy to operate.

[0043] In some preferred embodiments, the power of the plasma gun is 50-100 kW, for example, 50 kW, 60 kW, 70 kW, 80 kW, 90 kW, 100 kW, etc.

[0044] In some preferred embodiments, the operating frequency of the alternating current is a conventional frequency of 50 Hz, although other frequencies are not excluded. 50 Hz is a conventional frequency for industrial applications in this field, and the alternating current is 10 to 250 A, for example, 10 A, 20 A, 30 A, 40 A, 50 A, 60 A, 70 A, 80 A, 90 A, 100 A, 110 A, 120 A, 130 A, 140 A, 150 A, 160 A, 170 A, 180 A, 190 A, 200 A, 210 A, 220 A, 230 A, 240 A, 250 A, etc.

[0045] In some preferred embodiments, 3 to 4 excitation windings are evenly spaced along the circumference of the plasma furnace. When 3 excitation windings are evenly spaced, the spatial difference between two adjacent excitation windings is 120°, that is, the horizontal angle between two adjacent excitation windings and the axis of the plasma furnace is 120°; when 4 excitation windings are evenly spaced, the spatial difference between two adjacent excitation windings is 90°.

[0046] In some preferred embodiments, the axial direction of the excitation winding is perpendicular to the axial direction of the plasma furnace.

[0047] In some preferred embodiments, the upper surface of the solid mixture layer is between the upper end and the lower end of the excitation winding.

[0048] In some preferred embodiments, the process further comprises: filtering and cooling the obtained nano metal oxide powder, and collecting the nano metal oxide powder.

[0049] In some preferred embodiments, the filtration accuracy is 0.05-0.1 μm.

[0050] In some preferred embodiments, the filtration wind speed is 0.1~1 m / min, for example, 0.1 m / min, 0.2 m / min, 0.3 m / min, 0.4 m / min, 0.5 m / min, 0.6 m / min, 0.7 m / min, 0.8 m / min, 0.9 m / min, 1.0 m / min, etc.

[0051] In some embodiments, a filter element dust collector is provided between the plasma furnace and the exhaust assembly; the metal oxide obtained by the reaction enters the filter element dust collector under the action of the exhaust assembly and is filtered to obtain nano metal oxide powder.

[0052] In some preferred embodiments, the particle size of the solid mixture is less than 10 mesh (ie, less than 2 μm). In some preferred embodiments, the solid mixture is obtained by crushing raw materials and then mixing them.

[0053] In some preferred embodiments, the average particle size of the nano metal oxide powder is 20 to 100 nm, for example, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, 50 nm, 55 nm, 60 nm, 65 nm, 70 nm, 75 nm, 80 nm, 85 nm, 90 nm, 95 nm, 100 nm, etc.

[0054] The present invention also provides a system for preparing nano metal oxide powder, comprising: A plasma furnace, wherein the plasma furnace is provided with an air inlet, an air outlet and a feed inlet; A plasma gun, the plasma gun is arranged on the plasma furnace and is located above the solid mixture layer in the plasma furnace; the plasma generated by the plasma gun is used to gasify the solid mixture in the gasification furnace; An air intake assembly, the air intake assembly is communicated with the plasma furnace, the air intake assembly is used to guide air into the furnace from the air inlet, the air reacts with the gasified solid mixture to generate metal oxides, and the air cools the metal oxides into nano powders; A feed assembly, the discharge port of the feed assembly is connected to the feed port, and the feed assembly is used to uniformly transport materials into the furnace; A material receiving component, wherein the material inlet of the material receiving component is connected to the gas outlet, and the material receiving component is used to receive and cool the metal oxides generated by the reaction in the furnace and collect nano metal oxide powders; The excitation winding is arranged on the peripheral surface of the plasma furnace. The alternating magnetic field generated by the alternating current flowing through the excitation winding expands the size of the plasma in the horizontal direction.

[0055] In some embodiments, the air intake component may be an exhaust fan or a blower; when the air intake component is an exhaust fan, the exhaust fan is arranged downstream of the material receiving component, and is used to generate suction to draw air from the air inlet into the furnace body, and draw oxides generated by the reaction in the furnace body into the material receiving component; when the air intake component is a blower, the blower is directly connected to the air inlet of the furnace body, and is used to blow air into the furnace body, react with the gasified material in the furnace body to generate metal oxides, and blow the metal oxides into the material receiving component; preferably, the air intake component is an exhaust fan.

[0056] In some preferred embodiments, the plasma furnace comprises a furnace body and a furnace cover, a gap is provided between the furnace body and the furnace cover, and the gap is an air inlet. The plasma gun is provided on the furnace cover, the feed inlet is provided on the furnace body, and the air outlet is provided on the furnace cover.

[0057] In some embodiments, the feeding assembly includes a screw feeder or a vibrating feeder or other equipment that can achieve timed and fixed-point feeding.

[0058] In some preferred embodiments, the feed inlet is arranged below the upper surface of the solid mixture layer in the furnace.

[0059] In some embodiments, the feeding component also includes a crusher and a three-dimensional mixer; the crusher is arranged upstream of the three-dimensional mixer, and the three-dimensional mixer is arranged upstream of the screw feeder. The crusher is used to crush materials, and the three-dimensional mixer is used to mix the materials crushed by the crusher.

[0060] In some embodiments, the material receiving assembly includes a filter element dust collector, the feed port of the filter element dust collector is connected to the gas outlet, and the filter element dust collector is used to receive, cool and filter the metal oxides in the plasma furnace.

[0061] In some embodiments, the material collecting assembly further includes a barrel, which is disposed below the filter element dust collector and is used to collect the nano metal oxide powder obtained by filtration.

[0062] In some preferred implementations, 3 to 4 excitation windings are evenly spaced along the circumference of the plasma furnace.

[0063] In some preferred embodiments, the axial direction of the excitation winding is perpendicular to the axial direction of the plasma furnace.

[0064] In some preferred embodiments, the upper surface of the solid mixture layer is between the upper end and the lower end of the excitation winding.

[0065] In order to facilitate the understanding of the present invention, the present invention will be described in more comprehensive and detailed manner below in conjunction with the accompanying drawings and preferred embodiments of the specification, but the protection scope of the present invention is not limited to the following specific embodiments.

[0066] Preparation system example: A system for preparing nano metal oxide powder, such as Figure 1 As shown, including: A plasma furnace 4, wherein the plasma furnace 4 comprises a furnace body 4-1 and a furnace cover 4-2, wherein a gap is provided between the furnace body 4-1 and the furnace cover 4-2; the furnace body 4-1 is provided with a feed inlet, and the furnace cover 4-2 is provided with an air outlet; wherein the furnace body 4-1 may be a crucible; Plasma gun 5; the plasma gun 5 is arranged on the furnace cover 4-2; the plasma generated by the plasma gun 5 is used to heat and gasify the solid mixture in the furnace body 4-1; A screw feeder 3, the outlet of the screw feeder 3 is connected to the feed port, and the screw feeder 3 is used to uniformly transport materials into the furnace body 4-1; A filter element dust collector 6, wherein the feed port of the filter element dust collector 6 is connected to the gas outlet, and the filter element dust collector 4 is used to receive and filter the metal oxides generated by the reaction in the furnace body to obtain nano metal oxide powders; an exhaust fan, the exhaust fan being connected to the air outlet of the filter element dust collector 6, the exhaust fan being used to draw air from the gap into the furnace body 4-1, the air reacting with the gasified solid mixture to generate metal oxides and cooling the metal oxides into powders, and under the action of the exhaust fan, the metal oxides generated by the reaction in the plasma furnace 3 are drawn into the filter element dust collector 6 (specifically, the metal oxides generated by the reaction in the furnace body are drawn into the filter element dust collector 6, and the metal oxides in the filter element dust collector 6 are rapidly cooled into metal oxide powders under the action of a large amount of air, and the metal oxide powders are filtered and enter the barrel); A barrel, which is arranged below the discharge port of the filter element dust collector 6 and is used to receive the nano-metal oxide obtained after filtration; Excitation windings, multiple excitation windings are evenly spaced and arranged on the circumference of the furnace body 4-1, and the alternating magnetic field generated by the alternating current passed through the excitation windings expands the size of the plasma in the horizontal direction.

[0067] A bracket may be arranged below the furnace cover 4 - 2 , and the furnace cover 4 - 2 is arranged on the furnace body 4 - 1 through the bracket.

[0068] Preferably, three excitation windings are evenly spaced along the circumference of the furnace body 4-1, and the space difference between two adjacent excitation coils is 120°. Of course, four excitation coils can also be provided, and the space difference between two adjacent excitation coils is 90°.

[0069] The axial direction of the excitation winding is perpendicular to the axial direction of the plasma furnace.

[0070] The upper surface of the solid mixture layer is between the upper end and the lower end of the excitation winding.

[0071] It also includes a crusher 1 and a three-dimensional mixer 2, wherein the crusher 1 is used for crushing materials, the three-dimensional mixer 2 is arranged downstream of the crusher 1, the discharge port of the three-dimensional mixer 2 is arranged above the feed port of the screw feeder 3-1, and the three-dimensional mixer 2 is used for receiving and mixing the materials crushed by the crusher 1, and the materials mixed by the three-dimensional mixer 2 are transported to the furnace body 4-1 through the screw feeder 3-1.

[0072] In addition, there may be no gap between the furnace body 4-1 and the furnace cover 4-2, and the gap between the furnace body 4-1 and the furnace cover 4-2 may be replaced by providing an air inlet on the furnace body 4-1. The air inlet is provided below the plasma gun and above the upper surface of the material layer.

[0073] Preparation Example: Example 1 The system described in the above-mentioned preparation system embodiment is used to prepare nano oxides, such as Figure 1 As shown, the preparation method comprises: (1) Crushing and homogenizing: First, crush the 4N indium gallium zinc oxide waste target (IGZO) to less than 2 mm, and then mix the materials in a three-dimensional mixer; (2) Plasma gasification: Set the plasma furnace output power to 50 kW to gasify the crushed and mixed indium gallium zinc oxide powder in the crucible; at the same time, turn on the exhaust fan and screw feeder, and set the air volume to 5000m 3 / h, the feeding rate of the screw feeder is set to 20kg / h, and the feeding rate is set during the plasma gasification process to control the material layer height of the indium gallium zinc oxide powder in the crucible within the set material layer height ±1cm; three excitation windings are evenly spaced along the circumference of the furnace body, the axial direction of the excitation winding is perpendicular to the axial direction of the plasma furnace, the upper surface of the material layer is between the upper end and the lower end of the excitation winding, the excitation coil is energized, the working frequency is set to 50Hz, and the alternating current is 10A; (3) Product collection: The filtration wind speed in the filter element dust collector is 0.5m / min, and the filtration accuracy is 0.1μm. Nano-indium gallium zinc oxide powder is collected in the filter element dust collector and discharged from the barrel below.

[0074] The analysis results of the obtained nano-indium gallium zinc oxide powder are as follows: purity 99.99%, average particle size 95nm, important indicator BET (specific surface area) 25m 2 / g, the powder particles have good uniformity and there is no powder agglomeration, and the production capacity is 20kg of nano IGZO powder per hour.

[0075] Example 2 The system described in the above-mentioned preparation system embodiment is used to prepare nano oxides, such as Figure 1 As shown, the preparation method comprises: (1) Crushing and homogenizing: First, crush the 4N zinc oxide aluminum waste target (AZO) to less than 2 mm, and then mix the materials in a three-dimensional mixer; (2) Plasma gasification: Set the plasma furnace output power to 50 kW to gasify the zinc oxide aluminum powder in the crucible; at the same time, turn on the exhaust fan and screw feeder, and set the air volume to 5000m 3 / h, the screw feeder is set to feed at 25kg / h; in the plasma gasification process, the feed amount is set to control the material layer height of the indium gallium zinc oxide powder in the crucible within the set material layer height ±1cm; three excitation windings are evenly spaced along the circumference of the furnace body, the axial direction of the excitation winding is perpendicular to the axial direction of the plasma furnace, the upper surface of the material layer is between the upper end and the lower end of the excitation winding, the excitation coil is energized, the working frequency is set to 50Hz, and the alternating current is 20A; (3) Product collection: The filtration wind speed in the filter element dust collector is 0.4m / min, and the filtration accuracy is 0.1μm. Nano zinc oxide aluminum powder is collected in the filter element dust collector and discharged from the barrel below.

[0076] The analysis results of the obtained nano zinc oxide aluminum powder are as follows: purity 99.99%, average particle size 85nm, important index BET (specific surface area) 27m 2 / g, the powder particles have good uniformity and the powder has no agglomeration, and the production capacity is 25kg of nano AZO powder per hour.

[0077] Example 3 The system described in the above-mentioned preparation system embodiment is used to prepare nano oxides, such as Figure 1 As shown, the preparation method comprises: (1) Crushing and homogenizing: First, crush the 4N indium tin oxide waste target (ITO) to less than 2 mm, and then mix the materials in a three-dimensional mixer; (2) Plasma gasification: Set the plasma furnace output power to 65 kW to gasify the crushed and mixed indium tin oxide powder in the crucible; at the same time, turn on the exhaust fan and screw feeder, and set the air volume to 6000m 3 / h, the screw feeder is set to feed at 20kg / h; in the plasma gasification process, the feed amount is set to control the material layer height of the indium gallium zinc oxide powder in the crucible within the set material layer height ±1.5cm; three excitation windings are evenly spaced along the circumference of the furnace body, the axial direction of the excitation winding is perpendicular to the axial direction of the plasma furnace, the upper surface of the material layer is between the upper end and the lower end of the excitation winding, the excitation coil is energized, the working frequency is set to 50Hz, and the alternating current is 40A; (3) Product collection: The filtration wind speed in the filter element dust collector is 0.5m / min, and the filtration accuracy is 0.1μm. Nano indium tin oxide powder is collected in the filter element dust collector and discharged from the barrel below.

[0078] The analysis results of the obtained nano-indium tin oxide powder are as follows: purity 99.99%, average particle size 70nm, important index BET (specific surface area) 29m 2 / g, the powder particles have good uniformity and the powder has no agglomeration, and the production capacity is 20kg of nano ITO powder per hour.

[0079] Example 4 The system described in the above-mentioned preparation system embodiment is used to prepare nano oxides, such as Figure 1 As shown, the preparation method comprises: (1) Crushing and homogenizing: First, crush the 4N gallium zinc oxide waste target (GZO) to less than 2 mm, and then mix the materials in a three-dimensional mixer; (2) Plasma gasification: Set the plasma furnace output power to 70 kW to gasify the crushed and mixed gallium zinc oxide powder in the crucible; at the same time, turn on the exhaust fan and screw feeder, and set the air volume to 6500m 3 / h, the screw feeder is set to feed at 20kg / h; in the plasma gasification process, the feed amount is set to control the material layer height of the indium gallium zinc oxide powder in the crucible within the set material layer height ±1cm; three excitation windings are evenly spaced along the circumference of the furnace body, the axial direction of the excitation winding is perpendicular to the axial direction of the plasma furnace, the upper surface of the material layer is between the upper end and the lower end of the excitation winding, the excitation coil is energized, the working frequency is set to 50Hz, and the alternating current is 60A; (3) Product collection: The filtration wind speed in the filter element dust collector is 1.0m / min, and the filtration accuracy is 0.1μm. Nano-gallium zinc oxide powder is collected in the filter element dust collector and discharged from the barrel below.

[0080] The analysis results of the obtained nano-gallium zinc oxide powder are as follows: purity 99.99%, average particle size 63nm, important indicator BET (specific surface area) 30m 2 / g, the powder particles have good uniformity and there is no powder agglomeration, and the production capacity is 20kg of nano GZO powder per hour.

[0081] Example 5 The system described in the above-mentioned preparation system embodiment is used to prepare nano oxides, such as Figure 1 As shown, the preparation method comprises: (1) Crushing and homogenizing: First, crush the 4N antimony tin oxide waste target (ATO) to less than 2 mm, and then mix the materials in a three-dimensional mixer; (2) Plasma gasification: Set the plasma furnace output power to 75 kW to gasify the crushed and mixed tin antimony oxide powder in the crucible; at the same time, turn on the exhaust fan and screw feeder, and set the air volume to 7000m 3 / h, the feeding rate of the screw feeder is set to 25kg / h; in the plasma gasification process, the feeding rate is set to control the material layer height of the indium gallium zinc oxide powder in the crucible within the set material layer height ±1cm; three excitation windings are evenly spaced along the circumference of the furnace body, the axial direction of the excitation winding is perpendicular to the axial direction of the plasma furnace, the upper surface of the material layer is between the upper end and the lower end of the excitation winding, the excitation coil is energized, the working frequency is set to 50Hz, and the alternating current is 80A; (3) Product collection: The filtration wind speed in the filter element dust collector is 0.8m / min, and the filtration accuracy is 0.1μm. Nano-tin antimony oxide powder is collected in the filter element dust collector and discharged from the barrel below.

[0082] The analysis results of the obtained nano-tin oxide antimony powder are as follows: purity 99.99%, average particle size 57nm, important index BET (specific surface area) 31m 2 / g, the powder particles have good uniformity and no powder agglomeration, and the production capacity is 25kg of nano ATO powder per hour.

[0083] Example 6 The system described in the above-mentioned preparation system embodiment is used to prepare nano oxides, such as Figure 1 As shown, the preparation method comprises: (1) Crushing and homogenizing: First, crush the 4N indium gallium zinc alloy (wherein the metal mass ratio is In:Ga:Zn=1.017:1.014:1.004) to less than 2 mm, and then mix the materials in a three-dimensional mixer; (2) Plasma gasification: Set the plasma furnace output power to 80 kW to gasify the crushed and mixed indium gallium zinc alloy powder in the crucible; at the same time, turn on the exhaust fan and screw feeder, and set the air volume to 8000m 3 / h, the screw feeder is set to feed at 50kg / h; in the plasma gasification process, the feed amount is set to control the material layer height of the indium gallium zinc oxide powder in the crucible within the set material layer height ±2cm; three excitation windings are evenly spaced along the circumference of the furnace body, the axial direction of the excitation winding is perpendicular to the axial direction of the plasma furnace, the upper surface of the material layer is between the upper end and the lower end of the excitation winding, the excitation coil is energized, the working frequency is set to 50Hz, and the alternating current is 120A; (3) Product collection: The filtration wind speed in the filter element dust collector is 1.0m / min, and the filtration accuracy is 0.05μm. Nano-indium gallium zinc oxide powder is collected in the filter element dust collector and discharged from the barrel below.

[0084] The analysis results of the obtained indium gallium zinc oxide powder are as follows: purity 99.995%, average particle size 50nm, important indicator BET (specific surface area) 32m 2 / g, the powder particles have good uniformity and there is no powder agglomeration, and the production capacity is 62kg of nano indium gallium zinc oxide powder per hour.

[0085] Example 7 The system described in the above-mentioned preparation system embodiment is used to prepare nano oxides, such as Figure 1 As shown, the preparation method comprises: (1) Crushing and homogenizing: First, crush the 4N zinc-aluminum alloy (where the metal mass ratio is Zn:Al=74.416:1) to less than 2 mm, and then mix the materials in a three-dimensional mixer; (2) Plasma gasification: Set the plasma furnace output power to 80 kW to gasify the crushed and mixed zinc-aluminum alloy powder in the crucible; at the same time, turn on the exhaust fan and screw feeder, and set the air volume to 8500m 3 / h, the feeding rate of the screw feeder is set to 55kg / h; in the plasma gasification process, the feeding rate is set to control the material layer height of the indium gallium zinc oxide powder in the crucible within the set material layer height ±2cm; three excitation windings are evenly spaced along the circumference of the furnace body, the axial direction of the excitation winding is perpendicular to the axial direction of the plasma furnace, the upper surface of the material layer is between the upper end and the lower end of the excitation winding, the excitation coil is energized, the working frequency is set to 50Hz, and the alternating current is 140A; (3) Product collection: The filtration wind speed in the filter element dust collector is 0.3m / min, and the filtration accuracy is 0.05μm. Nano zinc oxide aluminum powder is collected in the filter element dust collector and discharged from the barrel below.

[0086] The analysis results of the obtained nano zinc oxide aluminum powder are as follows: purity 99.995%, average particle size 43nm, important index BET (specific surface area) 35m 2 / g, the powder particles have good uniformity and the powder has no agglomeration, and the production capacity is 69kg of nano zinc oxide aluminum powder per hour.

[0087] Example 8 The system described in the above-mentioned preparation system embodiment is used to prepare nano oxides, such as Figure 1 As shown, the preparation method comprises: (1) Crushing and homogenizing: First, crush the 4N indium-tin alloy (where the metal mass ratio is In:Sn=9.45:1) to less than 2 mm, and then mix the materials in a three-dimensional mixer; (2) Plasma gasification: Set the plasma furnace output power to 90 kW to gasify the crushed and mixed indium tin alloy powder in the crucible; at the same time, turn on the exhaust fan and screw feeder, and set the air volume to 9000m 3 / h, the screw feeder is set to feed at 60kg / h; in the plasma gasification process, the feed amount is set to control the material layer height of the indium gallium zinc oxide powder in the crucible within the set material layer height ±2cm; three excitation windings are evenly spaced along the circumference of the furnace body, the axial direction of the excitation winding is perpendicular to the axial direction of the plasma furnace, the upper surface of the material layer is between the upper end and the lower end of the excitation winding, the excitation coil is energized, the working frequency is set to 50Hz, and the alternating current is 160A; (3) Product collection: The filtration wind speed in the filter element dust collector is 0.3m / min, and the filtration accuracy is 0.05μm. The nano indium tin oxide powder is collected in the filter element dust collector and discharged from the barrel below.

[0088] The analysis results of the obtained nano-indium tin oxide powder are as follows: purity 99.995%, average particle size 37nm, important index BET (specific surface area) 37m 2 / g, the powder particles have good uniformity and the powder has no agglomeration, and the production capacity is 72kg of nano indium tin oxide powder per hour.

[0089] Example 9 The system described in the above-mentioned preparation system embodiment is used to prepare nano oxides, such as Figure 1 As shown, the preparation method comprises: (1) Crushing and homogenizing: First, crush the 4N gallium-zinc alloy (where the metal mass ratio is Zn:Ga=163.15:1) to less than 2 mm, and then mix the materials in a three-dimensional mixer; (2) Plasma gasification: Set the plasma furnace output power to 100 kW to gasify the crushed and mixed gallium-zinc alloy powder in the crucible; at the same time, turn on the exhaust fan and screw feeder, and set the air volume to 9500m 3 / h, the feeding rate of the screw feeder is set to 55kg / h; in the plasma gasification process, the feeding rate is set to control the material layer height of the indium gallium zinc oxide powder in the crucible within the set material layer height ±2cm; three excitation windings are evenly spaced along the circumference of the furnace body, the axial direction of the excitation winding is perpendicular to the axial direction of the plasma furnace, the upper surface of the material layer is between the upper end and the lower end of the excitation winding, the excitation coil is energized, the working frequency is set to 50Hz, and the alternating current is 200A; (3) Product collection: The filtration wind speed in the filter element dust collector is 0.1m / min, and the filtration accuracy is 0.05μm. Nano-gallium zinc oxide powder is collected in the filter element dust collector and discharged from the barrel below.

[0090] The analysis results of the obtained nano-gallium zinc oxide powder are as follows: purity 99.995%, average particle size 30nm, important index BET (specific surface area) 39m 2 / g, the powder particles have good uniformity and there is no powder agglomeration, and the production capacity is 69kg of nano-gallium zinc oxide powder per hour.

[0091] Example 10 The system described in the above-mentioned preparation system embodiment is used to prepare nano oxides, such as Figure 1 As shown, the preparation method comprises: (1) Crushing and homogenizing: First, crush the 4N tin-antimony alloy (where the metal mass ratio is Sn:Sb=8.486:1) to less than 2 mm, and then mix the materials in a three-dimensional mixer; (2) Plasma gasification: Set the plasma furnace output power to 100 kW to gasify the crushed and mixed tin-antimony alloy powder in the crucible; at the same time, turn on the exhaust fan and screw feeder, and set the air volume to 10,000 m 3 / h, the screw feeder is set to feed at 60kg / h; in the plasma gasification process, the feed amount is set to control the material layer height of the indium gallium zinc oxide powder in the crucible within the set material layer height ±2cm; three excitation windings are evenly spaced along the circumference of the furnace body, the axial direction of the excitation winding is perpendicular to the axial direction of the plasma furnace, the upper surface of the material layer is between the upper end and the lower end of the excitation winding, the excitation coil is energized, the working frequency is set to 50Hz, and the alternating current is 250A; (3) Product collection: The filtration wind speed in the filter element dust collector is 0.1m / min, and the filtration accuracy is 0.05μm. Nano-tin antimony oxide powder is collected in the filter element dust collector and discharged from the barrel below.

[0092] The analysis results of the obtained nano-tin oxide antimony powder are as follows: purity 99.995%, average particle size 20nm, important index BET (specific surface area) 56m 2 / g, the powder particles have good uniformity and the powder has no agglomeration, and the production capacity is 76kg of nano-tin antimony oxide powder per hour.

[0093] Embodiment 11 The system described in the above-mentioned preparation system embodiment is used to prepare nano oxides, such as Figure 1 As shown, the preparation method comprises: (1) Crushing and homogenizing: First, 4N indium gallium zinc oxide waste target, 4N indium gallium zinc alloy, 4N indium and 4N gallium are mixed according to the metal mass ratio In:Ga:Zn=1.017:1.014:1.004, added to the crusher and crushed to less than 2 mm, and then the materials are mixed in a three-dimensional mixer; (2) Plasma gasification: Set the plasma furnace output power to 90 kW to gasify the crushed and mixed powder in the crucible; at the same time, turn on the exhaust fan and screw feeder, and set the air volume to 9000m 3 / h, the screw feeder is set to feed at 40kg / h; in the plasma gasification process, the feed amount is set to control the material layer height of the indium gallium zinc oxide powder in the crucible within the set material layer height ±1.5cm; three excitation windings are evenly spaced along the circumference of the furnace body, the axial direction of the excitation winding is perpendicular to the axial direction of the plasma furnace, the upper surface of the material layer is between the upper end and the lower end of the excitation winding, the excitation coil is energized, the working frequency is set to 50Hz, and the alternating current is 120A; (3) Product collection: The filtration wind speed in the filter element dust collector is 0.1m / min, and the filtration accuracy is 0.05μm. Nano-indium gallium zinc oxide powder is collected in the filter element dust collector and discharged from the barrel below.

[0094] The analysis results of the obtained nano-indium gallium zinc oxide powder are as follows: purity 99.995%, average particle size 30nm, important indicator BET (specific surface area) 42m 2 / g, the powder particles have good uniformity and there is no powder agglomeration, and the production capacity is 49kg nano IGZO powder per hour.

[0095] Example 12 The system described in the above-mentioned preparation system embodiment is used to prepare nano oxides, such as Figure 1 As shown, the preparation method comprises: (1) Crushing and homogenizing: First, 4N zinc oxide aluminum waste target, 4N zinc aluminum alloy, 4N metal zinc, and 4N metal aluminum are crushed to less than 2 mm according to the metal mass ratio Zn:Al=74.416:1, and then the materials are mixed in a three-dimensional mixer; (2) Plasma gasification: Set the plasma furnace output power to 100 kW to gasify the crushed and mixed powder in the crucible; at the same time, turn on the exhaust fan and screw feeder, and set the air volume to 9500m 3 / h, the screw feeder is set to feed at 30kg / h; in the plasma gasification process, the feed amount is set to control the material layer height of the indium gallium zinc oxide powder in the crucible within the set material layer height ±1cm; three excitation windings are evenly spaced along the circumference of the furnace body, the axial direction of the excitation winding is perpendicular to the axial direction of the plasma furnace, the upper surface of the material layer is between the upper end and the lower end of the excitation winding, the excitation coil is energized, the working frequency is set to 50Hz, and the alternating current is 250A; (3) Product collection: The filtration wind speed in the filter element dust collector is 0.3m / min, and the filtration accuracy is 0.1μm. Nano zinc oxide aluminum powder is collected in the filter element dust collector and discharged from the barrel below.

[0096] The analysis results of the obtained nano zinc oxide aluminum powder are as follows: purity 99.995%, average particle size 25nm, important index BET (specific surface area) 47m 2 / g, the powder particles have good uniformity and there is no powder agglomeration, and the production capacity is 38kg of nano AZO powder per hour.

[0097] Example 13 The system described in the above-mentioned preparation system embodiment is used to prepare nano oxides, such as Figure 1 As shown, the preparation method comprises: (1) Crushing and homogenizing: First, the 4N indium tin oxide waste target, 4N indium tin alloy, 4N metal indium, and 4N metal tin are crushed to less than 2 mm according to the metal mass ratio In:Sn=9.45:1, and then the materials are mixed in a three-dimensional mixer; (2) Plasma gasification: Set the plasma furnace output power to 100 kW to gasify the crushed and mixed powder in the crucible; at the same time, turn on the exhaust fan and screw feeder, and set the air volume to 10,000 m 3 / h, the screw feeder is set to feed at 50kg / h; in the plasma gasification process, the feed amount is set to control the material layer height of the indium gallium zinc oxide powder in the crucible within the set material layer height ±2cm; three excitation windings are evenly spaced along the circumference of the furnace body, the axial direction of the excitation winding is perpendicular to the axial direction of the plasma furnace, the upper surface of the material layer is between the upper end and the lower end of the excitation winding, the excitation coil is energized, the working frequency is set to 50Hz, and the alternating current is 220A; (3) Product collection: The filtration wind speed in the filter element dust collector is 0.2m / min, and the filtration accuracy is 0.05μm. The nano indium tin oxide powder is collected in the filter element dust collector and discharged from the barrel below.

[0098] The analysis results of the obtained nano-indium tin oxide powder are as follows: purity 99.995%, average particle size 20nm, important index BET (specific surface area) 53m 2 / g, the powder particles have good uniformity and the powder has no agglomeration, and the production capacity is 60kg of nano ITO powder per hour.

[0099] Embodiment 14 The system described in the above-mentioned preparation system embodiment is used to prepare nano oxides, such as Figure 1 As shown, the preparation method comprises: (1) Crushing and homogenizing: First, the 4N gallium zinc oxide waste target, 4N gallium zinc alloy, 4N metal gallium, and 4N metal zinc are crushed to less than 2 mm according to the metal mass ratio Zn:Ga=163.15:1, and then the materials are mixed in a three-dimensional mixer; (2) Plasma gasification: Set the plasma furnace output power to 95 kW to gasify the crushed and mixed powder in the crucible; at the same time, turn on the exhaust fan and screw feeder, and set the air volume to 9500m 3 / h, the screw feeder is set to feed at 30kg / h; in the plasma gasification process, the feed amount is set to control the material layer height of the indium gallium zinc oxide powder in the crucible within the set material layer height ±1cm; three excitation windings are evenly spaced along the circumference of the furnace body, the axial direction of the excitation winding is perpendicular to the axial direction of the plasma furnace, the upper surface of the material layer is between the upper end and the lower end of the excitation winding, the excitation coil is energized, the working frequency is set to 50Hz, and the alternating current is 240A; (3) Product collection: The filtration wind speed in the filter element dust collector is 0.4m / min, and the filtration accuracy is 0.05μm. Nano-gallium zinc oxide powder is collected in the filter element dust collector and discharged from the barrel below.

[0100] The analysis results of the obtained nano-gallium zinc oxide powder are as follows: purity 99.995%, average particle size 23nm, important indicator BET (specific surface area) 55m 2 / g, the powder particles have good uniformity and there is no powder agglomeration, and the production capacity is 37kg of nano GZO powder per hour.

[0101] Embodiment 15 The system described in the above-mentioned preparation system embodiment is used to prepare nano oxides, such as Figure 1 As shown, the preparation method comprises: (1) Crushing and homogenizing: First, the 4N tin antimony oxide waste target, 4N tin antimony alloy, 4N metal antimony, and 4N metal tin are crushed to less than 2 mm according to the metal mass ratio Sn:Sb=8.486:1, and then the materials are mixed in a three-dimensional mixer; (2) Plasma gasification: Set the plasma furnace output power to 75 kW to gasify the crushed and mixed powder in the crucible; at the same time, turn on the exhaust fan and screw feeder, and set the air volume to 10,000 m 3 / h, the screw feeder is set to feed at 20kg / h; in the plasma gasification process, the feed amount is set to control the material layer height of the indium gallium zinc oxide powder in the crucible within the set material layer height ±1cm; three excitation windings are evenly spaced along the circumference of the furnace body, the axial direction of the excitation winding is perpendicular to the axial direction of the plasma furnace, the upper surface of the material layer is between the upper end and the lower end of the excitation winding, the excitation coil is energized, the working frequency is set to 50Hz, and the alternating current is 230A; (3) Product collection: The filtration wind speed in the filter element dust collector is 0.3m / min, and the filtration accuracy is 0.05μm. Nano-tin antimony oxide powder is collected in the filter element dust collector and discharged from the barrel below.

[0102] The analysis results of the obtained nano-tin oxide antimony powder are as follows: purity 99.995%, average particle size 24nm, important index BET (specific surface area) 57m 2 / g, the powder particles have good uniformity and no powder agglomeration, and the production capacity is 25kg of nano ATO powder per hour.

[0103] Comparative Example 1 The difference from Example 11 is that: with one hour as the beat, the feeding speed in the first half hour is 35kg / h, and the feeding speed in the second half hour is 45kg / h, ensuring that the material feeding speed is 40kg / h per hour, and the feeding speed is consistent with the embodiment.

[0104] The analysis results of the obtained nano IGZO powder are as follows: purity 99.995%, average particle size 300nm, specific surface area (BET) 9m 3 / g, with a production capacity of 49kg IGZO powder per hour.

[0105] Comparative Example 2 The difference from Example 12 is that: no excitation coil is used and there is no rotating magnetic field; The analysis results of the obtained nano zinc oxide aluminum powder are as follows: purity 99.995%, average particle size 200nm, important index BET (specific surface area) 15m 2 / g, with a production capacity of 28kg AZO powder per hour.

[0106] By comparing the data in Table 1, it is found that each embodiment can prepare nano metal oxide powder for ceramic target material with high purity, nanometer particle size (below 100 nm), large specific surface area, uniform particle size and no agglomeration.

[0107] As can be seen from Table 1, in Comparative Example 1, when a controllable amount of material is fed into the furnace body during the reaction process to achieve precise control of the material layer height, the particles of the metal oxide are significantly enlarged and become submicron-level. After analysis, this is because when the material layer height cannot be accurately and stably controlled, for example, in Comparative Example 1, as the reaction proceeds, the material stacking height decreases, but the position of the air inlet remains unchanged, resulting in a change in the wind speed on the reaction interface, causing the powder particle size to increase; in Comparative Example 2, when the excitation winding is not provided on the peripheral surface of the furnace body, the particles of the metal oxide are significantly coarser and the production capacity is significantly reduced. After analysis, this may be because the rotating magnetic field generated by the excitation winding can cause the plasma to rotate and thereby increase the size of the plasma in the horizontal direction, expand the reaction area, and make the temperature in the furnace more uniform, thereby reducing the particle size distribution of the output powder and increasing the production capacity.

[0108] Table 1 The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing nano metal oxide powder, characterized in that: The preparation is carried out by using a plasma furnace, wherein the plasma furnace is provided with a plasma gun, and the plasma gun is arranged above the solid mixed material layer in the plasma furnace. The preparation method comprises: The plasma generated by the plasma gun heats the solid mixture in the gasification furnace to obtain gaseous materials. During the gasification process, air enters the furnace, and the gaseous materials and air undergo oxidation reactions to obtain metal oxides. The metal oxides enter the material collection system driven by the air and are quickly cooled to obtain nano metal oxide powders. The solid mixture is one or more of metal oxides, metals, and alloys. During the process of heating and gasifying the solid mixture by the plasma gun, the solid mixture is transported into the furnace to maintain the material layer height of the solid mixture in the furnace at a set material layer height of ±2 cm; and an excitation winding is provided on the circumference of the plasma furnace. During the process of heating and gasifying the solid mixture by the plasma gun, an alternating current is passed through the excitation winding, and the generated alternating magnetic field expands the size of the plasma in the horizontal direction.

2. The method for preparing nano metal oxide powder according to claim 1, characterized in that: The air inlet flow rate is 5000~10000m 3 / h; Preferably, the plasma furnace is provided with an air inlet; the air inlet is located between the plasma gun and the solid mixture layer; Preferably, an exhaust fan is provided downstream of the plasma furnace, and the air inlet of the exhaust fan is connected to the air outlet of the plasma furnace; the air enters the furnace through the exhaust effect of the exhaust fan; Preferably, the gas outlet of the plasma furnace is located at the upper part of the plasma furnace.

3. The method for preparing nano metal oxide powder according to claim 1, characterized in that: The solid mixed material is one or more of indium gallium zinc oxide waste target material (IGZO), zinc aluminum oxide waste target material (AZO), indium tin oxide waste target material (ITO), gallium zinc oxide waste target material (GZO), antimony tin oxide (ATO) waste target material, indium gallium zinc alloy, zinc aluminum alloy, indium tin alloy, gallium zinc alloy, tin antimony alloy, metal indium, metal tin, metal gallium, metal zinc, metal aluminum, and metal antimony; Preferably, the purity of each component in the solid mixture is independently 4N or above.

4. The method for preparing nano metal oxide powder according to claim 1, characterized in that: The solid mixture feed rate is 20-150 kg / h, preferably 20-80 kg / h; Preferably, the solid mixture is transported into the furnace body by a screw feeder or a vibrating feeder.

5. The method for preparing nano metal oxide powder according to claim 1 or 4, characterized in that: The particle size of the solid mixture is less than 10 mesh; The solid mixture is obtained by crushing the raw materials and then mixing them.

6. The method for preparing nano metal oxide powder according to claim 1, characterized in that: The power of the plasma gun is 50-100 kW.

7. The method for preparing nano metal oxide powder according to claim 1, characterized in that: 3-4 excitation windings are evenly spaced along the circumference of the furnace body; The axial direction of the excitation winding is perpendicular to the axial direction of the plasma furnace; The upper surface of the solid mixture layer is between the upper end and the lower end of the excitation winding; The operating frequency of the alternating current is 50 Hz, and the alternating current is 10-250A.

8. The method for preparing nano metal oxide powder according to claim 1, characterized in that: Also includes: filtering and cooling the obtained nano metal oxide powder to collect the nano metal oxide powder; The filtration accuracy is 0.05~0.1μm; The wind speed of the filtration is 0.1~1m / min; The average particle size of the nano metal oxide powder is 20-100 nm.

9. A system for preparing nano metal oxide powder, characterized in that: include: A plasma furnace, wherein the plasma furnace is provided with an air inlet, an air outlet and a feed inlet; A plasma gun, the plasma gun is arranged on the plasma furnace and is located above the solid mixture layer in the plasma furnace; the plasma generated by the plasma gun is used to gasify the solid mixture in the gasification furnace; An air intake assembly, the air intake assembly is communicated with the plasma furnace, and the air intake assembly is used to guide air into the furnace from the air inlet; A feed assembly, the discharge port of the feed assembly is connected to the feed port, and the feed assembly is used to uniformly transport materials into the furnace; A material receiving component, wherein the material inlet of the material receiving component is connected to the gas outlet, and the material receiving component is used to receive and cool the metal oxides generated by the reaction in the furnace and collect nano metal oxide powders; The excitation winding is arranged on the peripheral surface of the plasma furnace. The alternating magnetic field generated by the alternating current flowing through the excitation winding expands the size of the plasma in the horizontal direction.

10. The system for preparing nano metal oxide powder according to claim 9, characterized in that: The material receiving assembly comprises a filter element dust collector, the feed port of the filter element dust collector is connected to the gas outlet, and the filter element dust collector is used to receive, cool and filter the metal oxides in the plasma furnace; 3-4 excitation windings are evenly spaced along the circumference of the plasma furnace; The axial direction of the excitation winding is perpendicular to the axial direction of the plasma furnace; The upper surface of the solid mixture layer is between the upper end and the lower end of the excitation winding.

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