A device for cleaning powder, a method for cleaning powder and use

Abstract

The application provides a device, a method and an application for cleaning powder, which comprises a shell, a flow cleaning cavity in the shell, at least one layer of hollow support plates arranged in the flow cleaning cavity along the direction from the top to the bottom of the shell, at least one material container arranged on each layer of the hollow support plates, at least one leakage hole arranged on the bottom and / or the side of the material container, and the material container is used for containing the powder to be cleaned; the device further comprises a liquid circulating assembly which is in communication with a liquid inlet arranged on the top of the shell and an inlet and outlet arranged on the bottom of the shell respectively, and a liquid outlet arranged on the side wall of the shell and in communication with the liquid circulating assembly, and the liquid outlet is located above the hollow support plate adjacent to the top of the shell. The device has the advantages of short time consumption, small consumption of acid liquid and water, low use cost, and can completely remove the metal and acid liquid on the surface of the silicon carbide powder.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of semiconductor materials, and relates to a powder cleaning device, in particular to a powder cleaning device, a powder cleaning method and application. BACKGROUND

[0002] Silicon carbide (SiC) is a third-generation semiconductor material with a wide band gap, a high critical electric field and a high saturation mobility, and has great advantages in the field of power devices and is widely used in new energy vehicles, photovoltaic power generation, railway transportation and power systems.

[0003] However, due to the stable physical and chemical properties of SiC, it is extremely difficult to grow SiC crystals. At present, the single crystal substrate used for making SiC devices is mainly prepared by a physical vapor transport (PVT) method, and the raw material is SiC powder. The purity, particle size and crystal form of the powder have certain influence on the quality of the SiC single crystal grown by the PVT method and the quality of the subsequent devices, especially the Al, Fe, Na, Co and Ni elements in the powder, which have a significant impact on the device end. At present, the widely used powder is basically large particle powder less than 40 mesh. The improved self-propagating method is generally used for industrial production to synthesize SiC. Since the process of synthesizing large particle size will cause the phenomenon of blockage of the material block, post-processing of crushing is required. However, there is a risk of metal contamination in the crushing process, which leads to a high surface metal content of the powder, and surface metal treatment is required. At present, the process for removing the surface metal of the powder in the industry is simple acid pickling and water washing to remove residual acid, but the process is time-consuming, requires a large amount of pure water and acid, and is low in efficiency, and there is a phenomenon that the surface metal and acid are not completely removed.

[0004] CN112371635A discloses a silicon carbide ceramic raw material impurity removal device, which comprises a base, a feeding table fixedly installed on the left side of the base through bolts, a discharging table fixedly installed on the right side of the base through bolts, and at least three cleaning boxes arranged in a linear array and fixedly installed in the middle of the base through bolts. The beneficial effect is that the impurity removal device can effectively transport the silicon carbide ceramic material in the material cage to the corresponding cleaning box for acid pickling, alkali washing and water washing through the cooperation of the driving motor and the first lifting push rod, so as to effectively utilize the acid and alkali resistance of the silicon carbide raw material to remove various soluble impurity components contained therein, and the entire cleaning process can be automatically completed on the same equipment. However, the silicon carbide ceramic raw material impurity removal device has a long time consumption and requires a large amount of pure water, acid and alkali, resulting in a high cost.

[0005] CN114314592A discloses a purification method and filtration device for recovering silicon carbide micro powder from silicon cutting waste slurry. The main steps are: ① Adding sodium silicate (0.2-0.4% by weight) to the raw material slurry and adjusting the pH to 7-8 with sodium hydroxide; ② Transferring the slurry to an acid washing tank and adding sulfuric acid and hydrofluoric acid in a mass ratio of 1:2-1:5 to adjust the pH to >5; ③ Transferring the slurry to an automatic filtration device to remove particles larger than 20μm; ④ Transferring the slurry to an alkaline washing tank, adding sodium hydroxide (3-7% by weight) to adjust the pH to 5-7, and then dehydrating and drying. The automatic filtration device includes: an outer rotating drum; an inner support connecting a motor and an inner winch for discharging material inside the outer rotating drum; a water inlet assembly and a feed assembly connecting the outer rotating drum; and a liquid receiving tray at the bottom of the outer rotating drum. However, the purification method and filtration device for recovering silicon carbide micro powder from silicon cutting waste slurry cannot remove the metal from the surface of silicon carbide micro powder.

[0006] Currently available powder cleaning devices all have certain drawbacks, including long cleaning times, high consumption of pure water and acid, and incomplete removal of metals and acids from the surface of silicon carbide powder. Therefore, it is crucial to develop and design a novel powder cleaning device and method. Summary of the Invention

[0007] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a powder cleaning device, a powder cleaning method and application. The powder cleaning device provided by this invention has a shorter time consumption, which is only 1 / 4 to 1 / 5 of the conventional method. It consumes less acid and water, has a lower cost, and can more thoroughly remove metal and acid from the surface of silicon carbide powder, making it suitable for large-scale promotion and use.

[0008] To achieve this objective, the present invention adopts the following technical solution:

[0009] In a first aspect, the present invention provides a powder washing device, the device comprising a housing, the housing having a flow washing chamber, and at least one layer of perforated support plate disposed in the flow washing chamber along the direction from the top to the bottom of the housing, each layer of the perforated support plate being provided with at least one material container, the material container having at least one drain hole on its bottom and / or side, the material container being used to hold the powder to be washed.

[0010] The device also includes a liquid circulation assembly, which is connected to a liquid inlet at the top of the housing and an inlet / outlet at the bottom of the housing. A liquid outlet connected to the liquid circulation assembly is also provided on the side wall of the housing, and the liquid outlet is located above a perforated support plate adjacent to the top of the housing.

[0011] The powder cleaning device provided by this invention has a shorter time consumption, only 1 / 4 to 1 / 5 of the conventional method, consumes less acid and water, has lower operating costs, and can more thoroughly remove metal and acid from the surface of silicon carbide powder, making it suitable for large-scale promotion and use.

[0012] Preferably, the liquid circulation assembly includes a liquid pipeline connecting the liquid inlet and the inlet / outlet, and a first switching valve, an acid-resistant pump, and a second switching valve are sequentially arranged on the liquid pipeline along the direction from the liquid inlet to the inlet / outlet;

[0013] The liquid pipeline is also provided with a water washing branch pipeline, one end of which is connected to the first switch valve and the other end is connected to the water storage tank.

[0014] The liquid pipeline is also provided with a circulation branch pipeline, one end of which is connected to the liquid outlet, and the other end is connected to the liquid pipeline between the first switch valve and the acid-resistant pump.

[0015] The liquid pipeline is also connected to an outlet branch pipeline, one end of which is connected to the second switch valve and the other end is connected to the drain outlet.

[0016] The liquid circulation assembly also includes an acid reservoir, which is connected to the liquid inlet.

[0017] Preferably, a sprayer communicating with the liquid inlet is provided at the top of the housing.

[0018] Preferably, the perforated support plate is provided with at least one perforated hole, and the area of ​​the perforated hole is smaller than the bottom surface area of ​​the material container.

[0019] Preferably, each layer of the hollow support plate is independently provided with 1 to 20 material containers, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20, but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0020] Preferably, the mass of the powder to be washed in each layer of the material container is 1 to 20 kg, for example, it can be 1 kg, 3 kg, 5 kg, 7 kg, 10 kg, 12 kg, 14 kg, 16 kg, 18 kg or 20 kg, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0021] Preferably, the diameter of the pore is greater than 100 mesh, for example, it can be 101 mesh, 105 mesh, 110 mesh, 120 mesh, 150 mesh, 180 mesh, 200 mesh, 250 mesh, 300 mesh, 500 mesh or 1000 mesh, but it is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0022] Preferably, a removable filter screen is provided inside the inlet and outlet.

[0023] Preferably, the device further includes an ultrasonic heating tank, on which an ultrasonic device and a heater are disposed, and liquid is disposed inside the ultrasonic heating tank, with the housing located in the liquid inside the ultrasonic heating tank.

[0024] The materials of the shell, material container, hollow support plate, liquid pipeline, first switch valve, second switch valve, sprayer and filter screen described in this invention are each independently composed of any one of polytetrafluoroethylene, polypropylene or graphite.

[0025] In a second aspect, the present invention provides a powder cleaning method using the apparatus described in the first aspect, the powder cleaning method comprising the following steps:

[0026] (1) After acid washing, the liquid circulation component controls the acid to be discharged from the inlet and outlet and then from the shell;

[0027] The circulating pickling includes: the liquid circulation component controls the acid in the cleaning chamber to flow out of the shell through the liquid outlet, and after passing through the liquid circulation component, it enters the shell through the inlet and outlet. The acid flows from the bottom to the top of the shell into the material container provided on each layer of the hollow support plate, and then flows out from the opening at the top of each layer of the material container. It then passes through the hollow support plate above each layer of the material container and finally flows out of the shell through the liquid outlet, thus realizing the circulating pickling.

[0028] (3) After the water is washed, the liquid circulation component controls the water to be discharged from the inlet and outlet of the housing;

[0029] The flowing water washing includes: the liquid circulation component controls the water in the flowing cleaning chamber to flow out of the housing through the liquid outlet, and after passing through the liquid circulation component, the water enters the housing through the inlet and outlet. The water flows from the bottom to the top of the housing into the material container provided on each layer of the hollow support plate, and then flows out from the opening at the top of each layer of the material container. It then passes through the hollow support plate above each layer of the material container and finally flows out of the housing through the liquid outlet, thus realizing the flowing water washing.

[0030] Preferably, the concentration of the acid solution is 1% to 80%, for example, 1%, 5%, 10%, 15%, 20%, 30%, 40%, 50%, 60%, 70% or 80%, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0031] Preferably, the acid solution comprises any one or a combination of at least two of hydrochloric acid, nitric acid, sulfuric acid, selenic acid, phosphoric acid, perchloric acid, hydrofluoric acid, hydrobromic acid, hydroiodic acid, hydrocyanic acid, sulfurous acid, nitrous acid, acetic acid, sulfonic acid, perhalocarboxylic acid, oxalic acid, dihaloacetic acid, malonic acid, or monohaloacetic acid. Typical but non-limiting combinations include the combination of hydrochloric acid and nitric acid, the combination of sulfuric acid and selenic acid, the combination of phosphoric acid and perchloric acid, the combination of hydrocyanic acid and sulfurous acid, or the combination of dihaloacetic acid, malonic acid, and monohaloacetic acid.

[0032] Preferably, the powder cleaning method further includes performing at least one first water wash before step (1). The first water wash includes: the liquid circulation component controls water to be injected into the flow cleaning chamber through the liquid inlet. The water flows sequentially into the material container provided on each layer of the hollow support plate along the direction from the top to the bottom of the shell, flows out from the drain hole provided on the bottom and / or side of each layer of the material container, and then passes through each layer of the hollow support plate until the water level in the flow cleaning chamber is higher than the surface of the powder to be washed in the material container adjacent to the top of the shell. Then the water injection is stopped. After standing for a first set time, the liquid circulation component controls the water to flow out from the inlet and outlet and then discharges.

[0033] Preferably, the first set time is 1 to 60 minutes, for example, it can be 1 minute, 3 minutes, 5 minutes, 7 minutes, 9 minutes, 12 minutes, 15 minutes, 20 minutes, 25 minutes, 30 minutes, 40 minutes, 50 minutes or 60 minutes, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0034] Preferably, the number of times the first water wash is 1 to 10 times, for example, it can be 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 times, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0035] Preferably, the powder cleaning method further includes a static acid washing between the first water washing and step (1). The static acid washing includes: the acid in the acid storage tank is injected into the flow cleaning chamber through the liquid inlet. The acid flows sequentially from the top to the bottom of the shell into the material container provided on each layer of the hollow support plate. It flows out from the drain hole provided on the bottom and / or side of each layer of the material container, and then passes through each layer of the hollow support plate until the acid liquid level in the flow cleaning chamber is higher than the inner wall of the shell corresponding to the liquid outlet. The acid injection is stopped, and the mixture is left to stand for a second set time.

[0036] Preferably, the second set time is 1 to 48 hours, for example, it can be 1 hour, 3 hours, 5 hours, 7 hours, 10 hours, 12 hours, 15 hours, 18 hours, 20 hours, 25 hours, 30 hours, 35 hours, 40 hours, 45 hours or 48 hours, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0037] Preferably, the cyclic pickling time is 1 to 50 hours, for example, it can be 1 hour, 3 hours, 5 hours, 10 hours, 12 hours, 15 hours, 20 hours, 25 hours, 30 hours, 35 hours, 40 hours, 45 hours or 50 hours, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0038] Preferably, the powder cleaning method further includes the acid circulation and ultrasonic cyclic acid washing between the acid circulation component controlling the acid to be discharged from the inlet and outlet of the housing. The ultrasonic cyclic acid washing includes: while maintaining the cyclic acid washing, turning on the ultrasonic device to perform a first cyclic ultrasonic treatment, the first cyclic ultrasonic treatment including a first ultrasonic treatment and a first settling treatment performed sequentially.

[0039] Preferably, the first ultrasonic treatment time is 5 to 180 minutes, and the first static treatment time is 5 to 600 minutes.

[0040] In this invention, the duration of the first ultrasonic treatment is 5 to 180 minutes, for example, it can be 5 minutes, 10 minutes, 15 minutes, 20 minutes, 25 minutes, 30 minutes, 35 minutes, 40 minutes, 50 minutes, 60 minutes, 80 minutes, 100 minutes, 120 minutes, 140 minutes, 160 minutes or 180 minutes, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0041] Preferably, the number of the first cycle of ultrasound is 1 to 10 times, for example, it can be 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 times, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0042] Preferably, the powder cleaning method further includes turning on the heater to perform a first heating treatment, which accompanies the entire ultrasonic cyclic acid washing process.

[0043] Preferably, the temperature of the first heat treatment is 40 to 80°C, for example, it can be 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C or 80°C, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0044] Preferably, the powder cleaning method further includes a second water wash between step (1) and step (2). The second water wash includes: the liquid circulation component controls water to be injected into the flow cleaning chamber through the liquid inlet. The water flows sequentially into the material container provided on each layer of the hollow support plate along the direction from the top to the bottom of the shell. It flows out from the drain hole provided on the bottom and / or side of each layer of the material container and then passes through each layer of the hollow support plate until the water level in the flow cleaning chamber is higher than the surface of the powder to be washed in the material container adjacent to the top of the shell. Then the water injection is stopped. After standing for a third set time, the liquid circulation component controls the water to flow out from the inlet and outlet and then discharge it.

[0045] Preferably, the third set time is 1 to 60 minutes, for example, it can be 1 minute, 5 minutes, 10 minutes, 15 minutes, 20 minutes, 25 minutes, 30 minutes, 40 minutes, 50 minutes or 60 minutes, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0046] Preferably, the second water washing is performed 1 to 5 times, for example, 1, 2, 3, 4 or 5 times, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0047] Preferably, the running water washing time is 1 to 200 minutes, for example, it can be 1 minute, 5 minutes, 10 minutes, 15 minutes, 20 minutes, 25 minutes, 30 minutes, 40 minutes, 50 minutes, 60 minutes, 80 minutes, 100 minutes, 120 minutes, 140 minutes, 160 minutes, 180 minutes or 200 minutes, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0048] Preferably, the powder cleaning method further includes the flowing water washing and the ultrasonic flowing water washing between the liquid circulation component controlling the water to be discharged from the inlet and outlet of the housing and then discharged. The ultrasonic flowing water washing includes: while maintaining the flowing water washing, turning on the ultrasonic device to perform a second cycle of ultrasonic washing. The second cycle of ultrasonic washing includes a second ultrasonic treatment and a second settling treatment performed sequentially.

[0049] Preferably, the second ultrasonic treatment time is 5 to 60 minutes, and the second static treatment time is 5 to 20 minutes.

[0050] In this invention, the duration of the second ultrasonic treatment is 5 to 60 minutes, for example, it can be 5 minutes, 10 minutes, 15 minutes, 20 minutes, 25 minutes, 30 minutes, 35 minutes, 40 minutes, 45 minutes, 50 minutes, 55 minutes or 60 minutes, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0051] Preferably, the number of cycles of ultrasound in the second cycle is 1 to 10, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 times, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0052] Preferably, the powder cleaning method further includes turning on the heater to perform a second heating treatment, which accompanies the entire ultrasonic flow water washing process.

[0053] Preferably, the temperature of the second heat treatment is 40 to 80°C, for example, it can be 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C or 80°C, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0054] As a preferred embodiment of the powder cleaning method of the present invention, the powder cleaning method includes the following steps:

[0055] (1) Perform 1 to 10 first water washes. The first water wash includes: the liquid circulation component controls water to be injected into the flow cleaning chamber through the liquid inlet. The water flows sequentially into the material container provided on each layer of hollow support plate along the direction from the top to the bottom of the shell. It flows out from the drain hole provided on the bottom and / or side of each layer of material container and then passes through each layer of hollow support plate until the water level in the flow cleaning chamber is higher than the surface of the powder to be washed in the material container adjacent to the top of the shell. Then the water injection is stopped. After standing for 1 to 60 minutes, the liquid circulation component controls the water to flow out from the inlet and outlet and then discharges it.

[0056] (2) Static pickling, wherein the static pickling includes: the acid in the acid reservoir is injected into the flow cleaning chamber through the liquid inlet, and the acid flows sequentially into the material container provided on each layer of the hollow support plate along the direction from the top to the bottom of the shell, flows out from the drain hole provided on the bottom and / or side of each layer of the material container, and then passes through each layer of the hollow support plate until the acid liquid level in the flow cleaning chamber is higher than the inner wall of the shell corresponding to the liquid outlet, and then the acid injection is stopped, and the acid is allowed to stand for 1 to 48 hours;

[0057] (3) Circulating pickling, wherein the circulating pickling includes: the liquid circulation component controls the acid in the cleaning chamber to flow out of the shell through the liquid outlet, and after passing through the liquid circulation component, it enters the shell through the inlet and outlet. The acid flows from the bottom to the top of the shell into the material container provided on each layer of the hollow support plate, and then flows out from the opening at the top of each layer of the material container, and then passes through the hollow support plate above each layer of the material container, and finally flows out of the shell through the liquid outlet to realize the circulating pickling. The acid circulation is carried out for 1 to 50 hours.

[0058] (4) Ultrasonic cyclic pickling, wherein the ultrasonic cyclic pickling includes: while maintaining cyclic pickling, turning on the heater to perform a first heating treatment, the temperature of the first heating treatment being 40-80°C, the first heating treatment accompanying the entire ultrasonic cyclic pickling process; turning on the ultrasonic device to perform 1-10 first cyclic ultrasonic cycles, the first cyclic ultrasonic cycles including a first ultrasonic treatment of 5-180 min and a first settling treatment of 5-600 min performed sequentially; after ultrasonic cyclic pickling, the liquid circulation component controls the acid to flow out from the inlet and outlet and then discharge.

[0059] (5) Perform 1 to 5 second water washes. The second water wash includes: the liquid circulation component controls water to be injected into the flow cleaning chamber through the liquid inlet. The water flows into the material container provided on each layer of the hollow support plate in the direction from the top to the bottom of the shell. It flows out from the drain hole provided on the bottom and / or side of each layer of the material container. It then passes through each layer of the hollow support plate until the water level in the flow cleaning chamber is higher than the surface of the powder to be washed in the material container adjacent to the top of the shell. Then the water injection is stopped. After standing for 1 to 60 minutes, the liquid circulation component controls the water to flow out from the inlet and outlet and then discharges it.

[0060] (6) Perform a flowing water wash for 1 to 200 minutes. The flowing water wash includes: the liquid circulation component controls the water in the flowing cleaning chamber to flow out of the shell through the liquid outlet, and after passing through the liquid circulation component, the water enters the shell through the inlet and outlet. The water flows from the bottom to the top of the shell into the material container provided on each layer of the hollow support plate, and then flows out from the opening at the top of each layer of the material container. It then passes through the hollow support plate above each layer of the material container and finally flows out of the shell through the liquid outlet, thus realizing the flowing water wash.

[0061] (7) Ultrasonic flowing water washing, wherein the ultrasonic flowing water washing includes: while maintaining the flowing water washing, turning on the heater to perform a second heating treatment, the temperature of the second heating treatment is 40-80°C, the second heating treatment accompanies the entire ultrasonic flowing water washing process; turning on the ultrasonic device to perform a second cycle of ultrasonic 1-10 times, the second cycle of ultrasonic 1-10 times, the second cycle of ultrasonic 1-10 times including a second ultrasonic treatment of 5-60 minutes and a second settling treatment of 5-20 minutes in sequence; after ultrasonic flowing water washing, the liquid circulation component controls the water to flow out from the inlet and outlet and then discharge.

[0062] Thirdly, the present invention provides an application of the apparatus described in the first aspect, the apparatus being used for cleaning silicon carbide powder.

[0063] Compared with the prior art, the present invention has the following beneficial effects:

[0064] The powder cleaning device provided by this invention has a shorter time consumption, only 1 / 4 to 1 / 5 of the conventional method, consumes less acid and water, has lower operating costs, and can more thoroughly remove metal and acid from the surface of silicon carbide powder, making it suitable for large-scale promotion and use. Attached Figure Description

[0065] Figure 1 This is a schematic diagram of a powder cleaning device provided in a specific embodiment of the present invention.

[0066] The components are as follows: 1-shell; 2-flow cleaning chamber; 3-perforated support plate; 4-material container; 5-liquid inlet; 6-inlet / outlet; 7-liquid outlet; 8-liquid pipeline; 9-first switch valve; 10-acid-resistant pump; 11-second switch valve; 12-water reservoir; 13-drain outlet; 14-acid reservoir; 15-sprayer; 16-ultrasonic heating tank. Detailed Implementation

[0067] It should be understood that in the description of this invention, the terms "upper," "lower," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0068] It should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "set," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0069] Those skilled in the art should understand that the present invention necessarily includes the necessary pipelines, conventional valves and general pump equipment for achieving complete process, but the above content is not the main innovation of the present invention. Those skilled in the art can add layouts based on process flow and equipment structure selection, and the present invention does not make any special requirements or specific limitations in this regard.

[0070] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0071] In one specific implementation, such as Figure 1 As shown, the present invention provides a powder washing device, the device including a housing, the housing having a flow washing chamber inside, and at least one layer of perforated support plate arranged in the flow washing chamber along the direction from the top to the bottom of the housing. Each layer of the perforated support plate is provided with at least one material container, and the material container is provided with at least one drain hole on the bottom and / or side. The material container is used to hold the powder to be washed.

[0072] The device also includes a liquid circulation assembly, which is connected to a liquid inlet at the top of the housing and an inlet / outlet at the bottom of the housing. A liquid outlet connected to the liquid circulation assembly is also provided on the side wall of the housing, and the liquid outlet is located above a perforated support plate adjacent to the top of the housing.

[0073] The powder cleaning device provided by this invention has a shorter time consumption, only 1 / 4 to 1 / 5 of the conventional method, consumes less acid and water, has lower operating costs, and can more thoroughly remove metal and acid from the surface of silicon carbide powder, making it suitable for large-scale promotion and use.

[0074] Furthermore, the liquid circulation assembly includes a liquid pipeline connecting the liquid inlet and the inlet / outlet, and along the direction from the liquid inlet to the inlet / outlet, a first switching valve, an acid-resistant pump, and a second switching valve are sequentially arranged on the liquid pipeline;

[0075] The liquid pipeline is also provided with a water washing branch pipeline, one end of which is connected to the first switch valve and the other end is connected to the water storage tank.

[0076] The liquid pipeline is also provided with a circulation branch pipeline, one end of which is connected to the liquid outlet, and the other end is connected to the liquid pipeline between the first switch valve and the acid-resistant pump.

[0077] The liquid pipeline is also connected to an outlet branch pipeline, one end of which is connected to the second switch valve and the other end is connected to the drain outlet.

[0078] The liquid circulation assembly also includes an acid reservoir, which is connected to the liquid inlet.

[0079] Furthermore, a sprayer communicating with the liquid inlet is provided at the top of the housing.

[0080] Furthermore, the hollow support plate is provided with at least one hollow hole, the area of ​​which is smaller than the bottom surface area of ​​the material container.

[0081] Furthermore, each of the hollow support plates is independently provided with 1 to 20 material containers.

[0082] Furthermore, the mass of the powder to be washed in each of the material containers is 1 to 20 kg.

[0083] Furthermore, the diameter of the leak hole is greater than 100 mesh.

[0084] Furthermore, a removable filter screen is provided inside the inlet and outlet.

[0085] Furthermore, the device also includes an ultrasonic heating tank, on which an ultrasonic device and a heater are disposed, and liquid is disposed inside the ultrasonic heating tank, with the housing located in the liquid inside the ultrasonic heating tank.

[0086] The materials of the shell, material container, hollow support plate, liquid pipeline, first switch valve, second switch valve, sprayer and filter screen described in this invention are each independently composed of any one of polytetrafluoroethylene, polypropylene or graphite.

[0087] Example 1

[0088] This embodiment provides a powder washing device, which includes a housing 1, inside which is a flow washing chamber 2. Along the top to the bottom of the housing 1, the flow washing chamber 2 is provided with two layers of perforated support plates 3. Each layer of perforated support plates 3 is provided with three material containers 4. The mass of the powder to be washed in each layer of material containers 4 is 5 kg. The bottom of each material container 4 is provided with six 120-mesh perforations. The material containers 4 are used to hold the powder to be washed. The perforated support plates 3 are provided with ten perforated holes. The area of ​​the perforated holes is smaller than the bottom area of ​​the material containers 4.

[0089] The device also includes a liquid circulation assembly, which includes a liquid pipe 8 connecting the liquid inlet 5 and the inlet / outlet 6. A sprayer 15 communicating with the liquid inlet 5 is provided at the top of the housing 1, and a removable filter screen is provided in the inlet / outlet 6.

[0090] Along the direction from the liquid inlet 5 to the inlet / outlet 6, the liquid pipeline 8 is sequentially provided with a first switching valve 9, an acid-resistant pump 10 and a second switching valve 11;

[0091] The liquid pipeline 8 is also provided with a water washing branch pipeline. One end of the water washing branch pipeline is connected to the first switch valve 9, and the other end is connected to the water storage tank 12.

[0092] The liquid pipeline 8 is also connected to an outlet branch pipeline. One end of the outlet branch pipeline is connected to the second switch valve 11, and the other end is connected to the drain outlet 13.

[0093] The liquid circulation assembly also includes an acid reservoir 14, which is connected to the liquid inlet 5;

[0094] The side wall of the housing 1 is also provided with a liquid outlet 7 that communicates with the liquid circulation assembly. The liquid outlet 7 is located above the hollow support plate 3 adjacent to the top of the housing 1.

[0095] The liquid pipeline 8 is also provided with a circulation branch pipeline. One end of the circulation branch pipeline is connected to the liquid outlet 7, and the other end is connected to the liquid pipeline 8 between the first switch valve 9 and the acid-resistant pump 10.

[0096] The device also includes an ultrasonic heating tank 16, on which an ultrasonic device and a heater are provided. Liquid is provided inside the ultrasonic heating tank 16, and the housing 1 is located in the liquid inside the ultrasonic heating tank 16.

[0097] Example 2

[0098] This embodiment provides a powder washing device, which includes a housing 1, inside which is a flow washing chamber 2. Along the top to the bottom of the housing 1, a perforated support plate 3 is disposed in the flow washing chamber 2. Ten material containers 4 are disposed on the perforated support plate 3. The mass of the powder to be washed in each material container 4 is 1 kg. Two 200-mesh perforations are respectively provided on the bottom and side of each material container 4. The material container 4 is used to hold the powder to be washed. The perforated support plate 3 is provided with thirty perforated holes, the area of ​​which is smaller than the bottom area of ​​the material container 4.

[0099] The device also includes a liquid circulation assembly, which includes a liquid pipe 8 connecting the liquid inlet 5 and the inlet / outlet 6. A sprayer 15 communicating with the liquid inlet 5 is provided at the top of the housing 1, and a removable filter screen is provided in the inlet / outlet 6.

[0100] Along the direction from the liquid inlet 5 to the inlet / outlet 6, the liquid pipeline 8 is sequentially provided with a first switching valve 9, an acid-resistant pump 10 and a second switching valve 11;

[0101] The liquid pipeline 8 is also provided with a water washing branch pipeline. One end of the water washing branch pipeline is connected to the first switch valve 9, and the other end is connected to the water storage tank 12.

[0102] The liquid pipeline 8 is also connected to an outlet branch pipeline. One end of the outlet branch pipeline is connected to the second switch valve 11, and the other end is connected to the drain outlet 13.

[0103] The liquid circulation assembly also includes an acid reservoir 14, which is connected to the liquid inlet 5;

[0104] The side wall of the housing 1 is also provided with a liquid outlet 7 that communicates with the liquid circulation assembly. The liquid outlet 7 is located above the hollow support plate 3 adjacent to the top of the housing 1.

[0105] The liquid pipeline 8 is also provided with a circulation branch pipeline. One end of the circulation branch pipeline is connected to the liquid outlet 7, and the other end is connected to the liquid pipeline 8 between the first switch valve 9 and the acid-resistant pump 10.

[0106] The device also includes an ultrasonic heating tank 16, on which an ultrasonic device and a heater are provided. Liquid is provided inside the ultrasonic heating tank 16, and the housing 1 is located in the liquid inside the ultrasonic heating tank 16.

[0107] Example 3

[0108] This embodiment provides a powder washing device, which includes a housing 1, inside which is a flow washing chamber 2. Along the top to the bottom of the housing 1, the flow washing chamber 2 is provided with five layers of perforated support plates 3. Each layer of perforated support plate 3 is provided with a material container 4. The mass of the powder to be washed in each layer of material container 4 is 20 kg. The bottom of the material container 4 is provided with five 800-mesh perforations. The material container 4 is used to hold the powder to be washed. The perforated support plate 3 is provided with twenty perforated holes. The area of ​​the perforated holes is smaller than the bottom area of ​​the material container 4.

[0109] The device also includes a liquid circulation assembly, which includes a liquid pipe 8 connecting the liquid inlet 5 and the inlet / outlet 6. A sprayer 15 communicating with the liquid inlet 5 is provided at the top of the housing 1, and a removable filter screen is provided in the inlet / outlet 6.

[0110] Along the direction from the liquid inlet 5 to the inlet / outlet 6, the liquid pipeline 8 is sequentially provided with a first switching valve 9, an acid-resistant pump 10 and a second switching valve 11;

[0111] The liquid pipeline 8 is also provided with a water washing branch pipeline. One end of the water washing branch pipeline is connected to the first switch valve 9, and the other end is connected to the water storage tank 12.

[0112] The liquid pipeline 8 is also connected to an outlet branch pipeline. One end of the outlet branch pipeline is connected to the second switch valve 11, and the other end is connected to the drain outlet 13.

[0113] The liquid circulation assembly also includes an acid reservoir 14, which is connected to the liquid inlet 5;

[0114] The side wall of the housing 1 is also provided with a liquid outlet 7 that communicates with the liquid circulation assembly. The liquid outlet 7 is located above the hollow support plate 3 adjacent to the top of the housing 1.

[0115] The liquid pipeline 8 is also provided with a circulation branch pipeline. One end of the circulation branch pipeline is connected to the liquid outlet 7, and the other end is connected to the liquid pipeline 8 between the first switch valve 9 and the acid-resistant pump 10.

[0116] The device also includes an ultrasonic heating tank 16, on which an ultrasonic device and a heater are provided. Liquid is provided inside the ultrasonic heating tank 16, and the housing 1 is located in the liquid inside the ultrasonic heating tank 16.

[0117] Application Example 1

[0118] This application example provides a powder cleaning method for the device described in Embodiment 1, the powder cleaning method comprising the following steps:

[0119] (1) Perform five first water washes. The first water wash includes: the liquid circulation component controls water to be injected into the flow cleaning chamber 2 through the liquid inlet 5. The water flows sequentially from the top to the bottom of the shell 1 into the material container 4 provided on each layer of hollow support plate 3, flows out from the drain holes provided on the bottom and / or side of each layer of material container 4, and then passes through each layer of hollow support plate 3 until the water level in the flow cleaning chamber 2 is higher than the surface of the powder to be washed in the material container 4 adjacent to the top of the shell 1. Then the water injection is stopped. After standing for 5 minutes, the liquid circulation component controls the water to flow out from the inlet and outlet 6 and then discharges it.

[0120] (2) Static pickling, wherein the static pickling includes: the acid in the acid reservoir 14 is injected into the flow cleaning chamber 2 through the liquid inlet 5, and the acid flows sequentially from the top to the bottom of the shell 1 into the material container 4 provided on each layer of the hollow support plate 3, flows out from the drain hole provided on the bottom and / or side of each layer of the material container 4, and then passes through each layer of the hollow support plate 3 until the acid liquid level in the flow cleaning chamber 2 is higher than the inner wall of the shell 1 corresponding to the liquid outlet 7, and then stops the injection of acid liquid, and stands for 1 hour;

[0121] (3) Circulating pickling, wherein the circulating pickling includes: the acid in the cleaning chamber controlled by the liquid circulation component flows out of the housing through the liquid outlet, and after passing through the liquid circulation component, it enters the housing 1 through the inlet and outlet 6. The acid flows from the bottom to the top of the housing 1 into the material container 4 provided on each layer of the hollow support plate 3, and then flows out from the opening at the top of each layer of the material container 4, and then passes through the hollow support plate 3 above each layer of the material container 4, and finally flows out of the housing 1 through the liquid outlet 7 to realize the circulating pickling. The acid circulation is carried out for 7 hours.

[0122] (4) Ultrasonic cyclic pickling, wherein the ultrasonic cyclic pickling includes: while maintaining the cyclic pickling, turning on the heater to perform a first heating treatment, the temperature of the first heating treatment is 60°C, the first heating treatment accompanies the entire ultrasonic cyclic pickling process; turning on the ultrasonic device to perform 5 first cyclic ultrasonic treatments, the first cyclic ultrasonic treatment includes a first ultrasonic treatment of 80 minutes and a first settling treatment of 40 minutes in sequence; after ultrasonic cyclic pickling, the liquid circulation component controls the acid to flow out from the inlet and outlet 6 and then discharge it.

[0123] (5) Perform three second water washes. The second water wash includes: the liquid circulation component controls water to be injected into the flow cleaning chamber 2 through the liquid inlet 5. The water flows sequentially from the top to the bottom of the shell 1 into the material container 4 provided on each layer of hollow support plate 3. The water flows out from the holes provided on the bottom and / or side of each layer of material container 4, and then passes through each layer of hollow support plate 3 until the water level in the flow cleaning chamber 2 is higher than the surface of the powder to be washed in the material container 4 adjacent to the top of the shell 1. Then the water injection is stopped. After standing for 10 minutes, the liquid circulation component controls the water to flow out from the inlet and outlet 6 and then discharges it.

[0124] (6) Perform a 40-minute flowing water wash, the flowing water wash includes: the liquid circulation component controls the water in the flowing cleaning chamber to flow out of the housing through the liquid outlet, and after passing through the liquid circulation component, it enters the housing 1 through the inlet and outlet 6. The water flows from the bottom to the top of the housing 1 into the material container 4 provided on each layer of hollow support plate 3, and then flows out from the opening at the top of each layer of material container 4, and then passes through the hollow support plate 3 above each layer of material container 4, and finally flows out of the housing 1 through the liquid outlet 7, thus realizing the flowing water wash;

[0125] (7) Ultrasonic flowing water washing, wherein the ultrasonic flowing water washing includes: while maintaining the flowing water washing, turning on the heater to perform a second heating treatment, the temperature of the second heating treatment is 60°C, the second heating treatment accompanies the entire ultrasonic flowing water washing process; turning on the ultrasonic device to perform a second cycle of ultrasonic 5 times, the second cycle of ultrasonic 5 times including a second ultrasonic treatment of 5 minutes and a second static treatment of 3 minutes in sequence; after ultrasonic flowing water washing, the liquid circulation component controls the water to flow out from the inlet and outlet 6 and then discharge it.

[0126] Application Example 2

[0127] This application example provides a powder cleaning method for the device described in Embodiment 1, the powder cleaning method comprising the following steps:

[0128] (1) Perform a first water wash, the first water wash includes: the liquid circulation component controls water to be injected into the flow cleaning chamber 2 through the liquid inlet 5, the water flows into the material container 4 provided on each layer of hollow support plate 3 in the direction from the top to the bottom of the shell 1, flows out from the leakage hole provided on the bottom and / or side of each layer of material container 4, and then passes through each layer of hollow support plate 3 until the water level in the flow cleaning chamber 2 is higher than the surface of the powder to be washed in the material container 4 adjacent to the top of the shell 1, then the water injection is stopped, and after standing for 10 minutes, the liquid circulation component controls the water to flow out from the inlet and outlet 6 and then discharges it.

[0129] (2) Static pickling, wherein the static pickling includes: the acid in the acid reservoir 14 is injected into the flow cleaning chamber 2 through the liquid inlet 5, and the acid flows sequentially from the top to the bottom of the shell 1 into the material container 4 provided on each layer of the hollow support plate 3, flows out from the drain hole provided on the bottom and / or side of each layer of the material container 4, and then passes through each layer of the hollow support plate 3 until the acid liquid level in the flow cleaning chamber 2 is higher than the inner wall of the shell 1 corresponding to the liquid outlet 7, and then stops the injection of acid liquid, and stands for 10 hours;

[0130] (3) Circulating pickling, wherein the circulating pickling includes: the liquid circulation component controls the acid in the cleaning chamber to flow out of the shell through the liquid outlet, and after passing through the liquid circulation component, it enters the shell 1 through the inlet and outlet 6. The acid flows from the bottom to the top of the shell 1 into the material container 4 provided on each layer of the hollow support plate 3, and then flows out from the opening at the top of each layer of the material container 4, and then passes through the hollow support plate 3 above each layer of the material container 4, and finally flows out of the shell 1 through the liquid outlet 7 to realize the circulating pickling. The acid circulation is carried out for 1 hour.

[0131] (4) Ultrasonic cyclic pickling, wherein the ultrasonic cyclic pickling includes: while maintaining the cyclic pickling, turning on the heater to perform a first heating treatment, the temperature of the first heating treatment is 80°C, the first heating treatment accompanies the entire ultrasonic cyclic pickling process; turning on the ultrasonic device to perform a first cycle of ultrasonic, the first cycle of ultrasonic includes a first ultrasonic treatment of 50 minutes and a first settling treatment of 10 minutes in sequence; after ultrasonic cyclic pickling, the liquid circulation component controls the acid to flow out from the inlet and outlet 6 and then discharge.

[0132] (5) Perform five second water washes. The second water wash includes: the liquid circulation component controls water to be injected into the flow cleaning chamber 2 through the liquid inlet 5. The water flows sequentially from the top to the bottom of the shell 1 into the material container 4 provided on each layer of hollow support plate 3. The water flows out from the holes provided on the bottom and / or side of each layer of material container 4, and then passes through each layer of hollow support plate 3 until the water level in the flow cleaning chamber 2 is higher than the surface of the powder to be washed in the material container 4 adjacent to the top of the shell 1. Then the water injection is stopped. After standing for 1 minute, the liquid circulation component controls the water to flow out from the inlet and outlet 6 and then discharges it.

[0133] (6) Perform a 100-minute flowing water wash, the flowing water wash includes: the liquid circulation component controls the water in the flowing cleaning chamber to flow out of the housing through the liquid outlet, and after passing through the liquid circulation component, it enters the housing 1 through the inlet and outlet 6. The water flows from the bottom to the top of the housing 1 into the material container 4 provided on each layer of hollow support plate 3, and then flows out from the opening at the top of each layer of material container 4, and then passes through the hollow support plate 3 above each layer of material container 4, and finally flows out of the housing 1 through the liquid outlet 7, thus realizing the flowing water wash;

[0134] (7) Ultrasonic flowing water washing, wherein the ultrasonic flowing water washing includes: while maintaining the flowing water washing, turning on the heater to perform a second heating treatment, the temperature of the second heating treatment is 40°C, the second heating treatment accompanies the entire ultrasonic flowing water washing process; turning on the ultrasonic device to perform a second cycle of ultrasound 10 times, the second cycle of ultrasound including a second ultrasound treatment of 5 minutes and a second settling treatment of 5 minutes in sequence; after ultrasonic flowing water washing, the liquid circulation component controls the water to flow out from the inlet and outlet 6 and then discharge it.

[0135] Application Example 3

[0136] This application example provides a powder cleaning method for the device described in Embodiment 1, the powder cleaning method comprising the following steps:

[0137] (1) Perform 10 first water washes. The first water wash includes: the liquid circulation component controls water to be injected into the flow cleaning chamber 2 through the liquid inlet 5. The water flows sequentially into the material container 4 provided on each layer of hollow support plate 3 along the direction from the top to the bottom of the shell 1. It flows out from the leakage holes provided on the bottom and / or side of each layer of material container 4, and then passes through each layer of hollow support plate 3 until the water level in the flow cleaning chamber 2 is higher than the surface of the powder to be washed in the material container 4 adjacent to the top of the shell 1. Then the water injection is stopped. After standing for 1 minute, the liquid circulation component controls the water to flow out from the inlet and outlet 6 and then discharges it.

[0138] (2) Static pickling, wherein the static pickling includes: the acid in the acid reservoir 14 is injected into the flow cleaning chamber 2 through the liquid inlet 5, and the acid flows sequentially from the top to the bottom of the shell 1 into the material container 4 provided on each layer of the hollow support plate 3, flows out from the drain hole provided on the bottom and / or side of each layer of the material container 4, and then passes through each layer of the hollow support plate 3 until the acid liquid level in the flow cleaning chamber 2 is higher than the inner wall of the shell 1 corresponding to the liquid outlet 7, and then stops the injection of acid liquid, and stands for 5 hours;

[0139] (3) Circulating pickling, wherein the circulating pickling includes: the acid in the cleaning chamber controlled by the liquid circulation component flows out of the housing through the liquid outlet, and after passing through the liquid circulation component, it enters the housing 1 through the inlet and outlet 6. The acid flows from the bottom to the top of the housing 1 into the material container 4 provided on each layer of the hollow support plate 3, and then flows out from the opening at the top of each layer of the material container 4, and then passes through the hollow support plate 3 above each layer of the material container 4, and finally flows out of the housing 1 through the liquid outlet 7, thereby realizing the circulating pickling. The acid circulation is carried out for 5 hours.

[0140] (4) Ultrasonic cyclic pickling, wherein the ultrasonic cyclic pickling includes: while maintaining the cyclic pickling, turning on the heater to perform a first heating treatment, the temperature of the first heating treatment is 40°C, the first heating treatment accompanies the entire ultrasonic cyclic pickling process; turning on the ultrasonic device to perform three first cyclic ultrasonic treatments, the first cyclic ultrasonic treatments include a first ultrasonic treatment of 60 minutes and a first settling treatment of 40 minutes in sequence; after ultrasonic cyclic pickling, the liquid circulation component controls the acid to flow out from the inlet and outlet 6 and then discharge it.

[0141] (5) Perform a second water wash, the second water wash includes: the liquid circulation component controls water to be injected into the flow cleaning chamber 2 through the liquid inlet 5, the water flows into the material container 4 provided on each layer of hollow support plate 3 in the direction from the top to the bottom of the shell 1, flows out from the leakage hole provided on the bottom and / or side of each layer of material container 4, and then passes through each layer of hollow support plate 3 until the water level in the flow cleaning chamber 2 is higher than the surface of the powder to be washed in the material container 4 adjacent to the top of the shell 1, then the water injection is stopped, and after standing for 60 minutes, the liquid circulation component controls the water to flow out from the inlet and outlet 6 and then discharges it.

[0142] (6) Perform a 200-minute flowing water wash, the flowing water wash includes: the liquid circulation component controls the water in the flowing cleaning chamber to flow out of the housing through the liquid outlet, and after passing through the liquid circulation component, it enters the housing 1 through the inlet and outlet 6. The water flows from the bottom to the top of the housing 1 into the material container 4 provided on each layer of hollow support plate 3, and then flows out from the opening at the top of each layer of material container 4, and then passes through the hollow support plate 3 above each layer of material container 4, and finally flows out of the housing 1 through the liquid outlet 7, thus realizing the flowing water wash;

[0143] (7) Ultrasonic flowing water washing, wherein the ultrasonic flowing water washing includes: while maintaining the flowing water washing, turning on the heater to perform a second heating treatment, the temperature of the second heating treatment is 80°C, the second heating treatment accompanies the entire ultrasonic flowing water washing process; turning on the ultrasonic device to perform a second cycle of ultrasonic 5 times, the second cycle of ultrasonic 5 times including a second ultrasonic treatment of 30 minutes and a second settling treatment of 10 minutes in sequence; after ultrasonic flowing water washing, the liquid circulation component controls the water to flow out from the inlet and outlet 6 and then discharge it.

[0144] Comparative Example 1

[0145] This comparative example provides a conventional powder cleaning method, which includes the following steps: first, soaking the powder in acid solution for 24 hours, rinsing it with pure water 5-10 times after soaking, and continuing to rinse the powder with pure water, repeating this action 40-60 times.

[0146] The total time for the conventional powder cleaning method provided in the comparative example is 50 hours.

[0147] By comparing the total time of the powder cleaning method in Example 1 with the total time of the powder cleaning method in Comparative Example 1, it can be seen that the powder cleaning device provided by the present invention has a shorter time consumption, which is only 1 / 4 to 1 / 5 of the conventional method.

[0148] The silicon carbide powder cleaned using the powder cleaning method provided in this embodiment was subjected to GDMS testing. The test results showed that the silicon carbide powder contained 0.03 ppm of B, less than 1 ppm of F, less than 0.01 ppm of Na, 0.11 ppm of Al, 0.22 ppm of S, 0.07 ppm of Cl, less than 0.1 ppm of K, less than 0.1 ppm of Ca, less than 0.1 ppm of Sc, less than 0.05 ppm of Ti, less than 0.03 ppm of Ti, less than 0.01 ppm of V, less than 0.1 ppm of Cr, less than 0.05 ppm of Fe, less than 0.01 ppm of Ni, and less than 0.05 ppm of Cu. Therefore, the powder cleaning method provided in this embodiment can significantly reduce the surface metal content of silicon carbide powder.

[0149] The silicon carbide powder cleaned using the powder cleaning method in Comparative Example 1 was subjected to GDMS testing. The results showed that the content of each element in the silicon carbide powder was as follows: B 0.1 ppm, F less than 1 ppm, Na 0.29 ppm, Al 0.36 ppm, S 0.24 ppm, Cl 0.18 ppm, K less than 0.1 ppm, Ca less than 0.1 ppm, Sc less than 0.05 ppm, Ti 0.06 ppm, V less than 0.01 ppm, Cr less than 0.1 ppm, Fe less than 0.05 ppm, Ni less than 0.01 ppm, and Cu less than 0.05 ppm.

[0150] By comparing the elemental content of the cleaned silicon carbide powder in Example 1 with that in Comparative Example 1, it can be seen that the powder cleaning device and powder cleaning method provided by the present invention can thoroughly remove the metal and acid from the surface of silicon carbide powder, and are suitable for large-scale promotion and use.

[0151] The above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A method for cleaning powder, characterized in that, The powder cleaning method is carried out using a powder cleaning device, which includes a housing and a flow cleaning chamber inside the housing. Along the direction from the top to the bottom of the housing, at least one layer of perforated support plate is provided in the flow cleaning chamber. At least one material container is provided on each layer of perforated support plate. At least one leakage hole is provided on the bottom and / or side of the material container. The material container is used to hold the powder to be cleaned. The device also includes a liquid circulation assembly, which is connected to a liquid inlet at the top of the housing and an inlet / outlet at the bottom of the housing. A liquid outlet connected to the liquid circulation assembly is also provided on the side wall of the housing, and the liquid outlet is located above a perforated support plate adjacent to the top of the housing. The powder cleaning method includes the following steps: (1) Perform 1 to 10 first water washes. The first water wash includes: the liquid circulation component controls water to be injected into the flow cleaning chamber through the liquid inlet. The water flows into the material container provided on each layer of the hollow support plate in the direction from the top to the bottom of the shell. It flows out from the drain hole provided on the bottom and / or side of each layer of the material container and then passes through each layer of the hollow support plate until the water level in the flow cleaning chamber is higher than the surface of the powder to be washed in the material container adjacent to the top of the shell. Then the water injection is stopped. After standing for 1 to 60 minutes, the liquid circulation component controls the water to flow out from the inlet and outlet and then discharges it. (2) Static pickling, wherein the static pickling includes: the acid in the acid reservoir is injected into the flow cleaning chamber through the liquid inlet, and the acid flows into the material container provided on each layer of the hollow support plate in the direction from the top to the bottom of the shell, flows out from the drain hole provided on the bottom and / or side of each layer of the material container, and then passes through each layer of the hollow support plate until the acid liquid level in the flow cleaning chamber is higher than the inner wall of the shell corresponding to the liquid outlet, and then stops the injection of acid liquid, and stands for 1~48 hours; (3) Circulating pickling, wherein the circulating pickling includes: the liquid circulation component controls the acid in the cleaning chamber to flow out of the shell through the liquid outlet, and after passing through the liquid circulation component, it enters the shell through the inlet and outlet. The acid flows from the bottom to the top of the shell into the material container provided on each layer of the hollow support plate, and then flows out from the opening at the top of each layer of the material container, and then passes through the hollow support plate above each layer of the material container, and finally flows out of the shell through the liquid outlet to realize the circulating pickling. The circulating pickling is carried out for 1 to 50 hours. (4) Ultrasonic cyclic pickling, wherein the ultrasonic cyclic pickling includes: while maintaining the cyclic pickling, turning on the heater to perform a first heating treatment, the temperature of the first heating treatment is 40~80℃, the first heating treatment accompanies the entire ultrasonic cyclic pickling process; turning on the ultrasonic device to perform 1~10 first cyclic ultrasonic treatments, the first cyclic ultrasonic treatments include a first ultrasonic treatment of 5~180min and a first settling treatment of 5~600min performed sequentially; after ultrasonic cyclic pickling, the liquid circulation component controls the acid to flow out from the inlet and outlet and then discharge. (5) Perform 1 to 5 second water washes. The second water wash includes: the liquid circulation component controls water to be injected into the flow cleaning chamber through the liquid inlet. The water flows sequentially into the material container provided on each layer of the hollow support plate along the direction from the top to the bottom of the shell. It flows out from the drain hole provided on the bottom and / or side of each layer of the material container and then passes through each layer of the hollow support plate until the water level in the flow cleaning chamber is higher than the surface of the powder to be washed in the material container adjacent to the top of the shell. Then the water injection is stopped. After standing for 1 to 60 minutes, the liquid circulation component controls the water to flow out from the inlet and outlet and then discharges it. (6) Perform a flowing water wash for 1 to 200 minutes. The flowing water wash includes: the liquid circulation component controls the water in the flowing cleaning chamber to flow out of the shell through the liquid outlet, and after passing through the liquid circulation component, the water enters the shell through the inlet and outlet. The water flows from the bottom to the top of the shell into the material container provided on each layer of the hollow support plate, and then flows out from the opening at the top of each layer of the material container. It then passes through the hollow support plate above each layer of the material container and finally flows out of the shell through the liquid outlet, thus realizing the flowing water wash. (7) Ultrasonic flowing water washing, wherein the ultrasonic flowing water washing includes: while maintaining the flowing water washing, turning on the heater to perform a second heating treatment, the temperature of the second heating treatment is 40~80℃, the second heating treatment accompanies the entire ultrasonic flowing water washing process; turning on the ultrasonic device to perform a second cycle of ultrasonic 1~10 times, the second cycle of ultrasonic 1~10 times, the second cycle of ultrasonic 1~10 times including a second ultrasonic treatment of 5~60 minutes and a second settling treatment of 5~20 minutes in sequence; after ultrasonic flowing water washing, the liquid circulation component controls the water to flow out from the inlet and outlet and then discharge.

2. The powder cleaning method according to claim 1, characterized in that, The liquid circulation assembly includes a liquid pipeline connecting the liquid inlet and the inlet / outlet. Along the direction from the liquid inlet to the inlet / outlet, a first switching valve, an acid-resistant pump, and a second switching valve are sequentially arranged on the liquid pipeline. The liquid pipeline is also provided with a water washing branch pipeline, one end of which is connected to the first switch valve and the other end is connected to the water storage tank. The liquid pipeline is also provided with a circulation branch pipeline, one end of which is connected to the liquid outlet, and the other end is connected to the liquid pipeline between the first switch valve and the acid-resistant pump. The liquid pipeline is also connected to an outlet branch pipeline, one end of which is connected to the second switch valve and the other end is connected to the drain outlet. The liquid circulation assembly also includes an acid reservoir, which is connected to the liquid inlet.

3. The powder cleaning method according to claim 1, characterized in that, A sprayer connected to the liquid inlet is provided at the top of the housing.

4. The powder cleaning method according to claim 1, characterized in that, The perforated support plate is provided with at least one perforated hole, and the area of ​​the perforated hole is smaller than the bottom area of ​​the material container.

5. The powder cleaning method according to claim 1, characterized in that, Each layer of the hollow support plate is independently equipped with 1 to 20 material containers.

6. The powder cleaning method according to claim 1, characterized in that, The mass of the powder to be washed in each of the material containers is 1~20kg.

7. The powder cleaning method according to claim 1, characterized in that, The diameter of the leak is greater than 100 mesh.

8. The powder cleaning method according to claim 1, characterized in that, The inlet and outlet are equipped with removable filters.

9. The powder cleaning method according to any one of claims 1 to 8, characterized in that, The device also includes an ultrasonic heating tank, on which an ultrasonic device and a heater are provided. Liquid is provided inside the ultrasonic heating tank, and the housing is located in the liquid inside the ultrasonic heating tank.

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