Micro-nano powder washing, dispersing and filtering device

Abstract

The utility model discloses a micro-nano powder washing, dispersing and filtering device, which relates to the technical field of powder washing and separating equipment and comprises an outer barrel and a centrifugal barrel, a plurality of through holes I are arranged on the barrel wall of the centrifugal barrel, filter cloth is mounted close to the inner wall of the centrifugal barrel, the barrel bottom of the centrifugal barrel is a smooth arc-shaped bottom surface, and a discharge port is arranged in the center of the bottom of the centrifugal barrel. The bottom of the centrifugal barrel is connected with a driving motor I through a transmission assembly penetrating through the outer barrel, the driving motor I drives the centrifugal barrel to rotate, a liquid outlet is formed in the bottom of the outer barrel, and the problems that in the prior art, micro-nano powder is difficult to wash and disperse, and agglomeration and hardening are prone to occurring when a conventional centrifugal machine is adopted for washing and dispersing are solved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of powder equipment technology of preparing new chemical materials, food medicine, electronic material etc. BACKGROUND

[0002] Micro-nano powder material mainly refers to the material with particle size in micron level and nanometer level, and is commonly seen in spherical or ellipsoidal particles with particle size between 100nm and 100um. Because the micro-nano particles have special small size effect and high surface energy, they show special performance in optics, heat conduction, electricity conduction, metallization and magnetism. Common micro-nano powder materials are mainly applied in the following aspects: semiconductor electronic information industry, such as ultra-fine metal powder for conductive paste, ultra-fine silver powder, ultra-fine copper powder, ultra-fine nickel powder, ultra-fine aluminum powder, ultra-fine tungsten powder, ultra-fine platinum powder, etc.; nickel cobalt lithium carbonate, lithium carbonate, carbon powder and other electrode materials applied in new energy batteries; various coating ceramic powder such as titanium dioxide, zinc oxide, silicon powder, zirconium oxide, silicon carbide, etc. applied in chemical industry ceramic new energy; calcium carbonate, starch, glucose, ascorbic acid, food additives, etc. applied in food medicine; wollastonite powder, silicate powder, refractory material powder, etc. applied in building industry.

[0003] Most of the above-mentioned powders are prepared by wet chemical method or need to be washed, filtered and dried. Micro-nano powder particles are small, and particles will spontaneously agglomerate or even be cemented into blocks. If the particle agglomeration is serious, it will reduce the performance advantage of micro-nano powder. In the application fields of new chemical materials, new energy and semiconductors, it is required that the powder has high purity and dispersibility. In order to improve the purity of the powder, a fine washing process is needed. The dispersibility and purity of ultra-fine powder prepared by wet chemical method are contradictory, which brings great difficulty to engineering technology. Except for the salt particles crystallized out, most powders are insoluble in water or other solvents, or have slow solubility. Theoretically, the impurities can be removed by washing. With the rapid development of China's industry and technology, the demand for various ultra-fine powders, especially metal powders, ceramic powders and coatings, has increased dramatically. It is a challenge for current engineering technology to solve the purity and dispersibility of powders in large scale.

[0004] At present, the conventional washing and filtering equipment and technology can meet the filtering and washing of particles above several hundred microns, but cannot meet the industrial fine needs of micron-level, nanometer-level and special performance powders. The washing and filtering treatment capacity, washing efficiency, dispersing effect and product rate of the powder are restricted by equipment and process technology. For example, in the semiconductor industry, micro-nano ultra-fine silver powder has excellent electrical conductivity, thermal conductivity, metal stability and weldability, and becomes an important electrode packaging material. Ultra-fine silver powder is prepared by wet chemical oxidation-reduction, and the particle size of silver powder is between 50nm and 1500nm, and the specific surface area is between 0.5 and 12m2 / g.2 The silver powder has small particle size, high specific surface area and high bulk density.

[0005] In order to ensure good dispersibility of the silver powder, a large amount of dispersants and surfactants are generally added in the synthesis stage, and the surface of the silver particles is roughened to increase the specific surface area of the silver particles, which causes the silver powder to adsorb a large amount of organic matter, salt and other harmful ions. These impurities seriously affect the application performance of the silver powder in products, and the silver powder needs to be washed and filtered to remove the impurities. However, the removal of these impurities often causes secondary agglomeration of the particles. The existing washing method is to pour the synthesized silver powder into a filter kettle, remove the solvent by positive pressure or negative pressure, and then repeatedly inject a certain amount of pure water, which is filtered after manual stirring. This way of cleaning the silver powder can easily block the filter holes, and cannot be scaled up, which affects the final water content, purity, dispersibility, yield and processing efficiency of the silver powder. With the advent of industrial centrifuges, some of the difficulties in washing and filtering powder have been solved, but there are still technical bottlenecks in filtering and dispersing high-value-added powders such as metal and ceramic powders.

[0006] Industrial centrifuges have high centrifugal force separation coefficient and are good for separating large particle powder materials, especially for sewage treatment and food processing wastewater treatment, and have high processing efficiency without considering the damage of centrifugal force to the powder. However, for metal and ceramic powders, the particles are finer, the protective layer on the particle surface is thinner, and the specific gravity of the powder is larger. Under the action of the centrifuge, small particles often flow through the filter and are lost, and the filter cake is easily agglomerated and hardened under the action of centrifugal force. Once agglomerated and hardened, it is difficult to disperse again, and the performance of the powder itself is damaged. Therefore, the commonly used industrial centrifuge in the prior art is not suitable for washing micro-nano powder. Practical new type content

[0007] The utility model aims at solving the washing and dispersing difficulties of micro-nano powder in the prior art, and the problem of easy agglomeration and hardening in the washing and dispersing of the conventional centrifuge.

[0008] In order to achieve the above-mentioned purpose of the invention, the technical scheme of the utility model is as follows:

[0009] A micro-nano powder washing and dispersing filter device, comprising an outer barrel and a centrifugal barrel, a plurality of through holes I are formed in the barrel wall of the centrifugal barrel, a filter cloth is installed next to the inner wall of the centrifugal barrel, the bottom of the centrifugal barrel is a smooth arc surface, a discharge port is arranged at the center of the bottom of the centrifugal barrel, the bottom of the centrifugal barrel is connected with a driving motor I through a transmission assembly penetrating the outer barrel, the driving motor I drives the rotation of the centrifugal barrel, and a liquid discharge port is arranged at the bottom of the outer barrel.

[0010] Further, the detachable cover is further connected with a feeding pipe and a high-pressure water / hot air pipe, a plurality of through holes II are formed on the high-pressure water / hot air pipe, and the through holes II are directed to the filter cloth.

[0011] Further, the high-pressure water / hot air pipe extends into the lower part of the centrifugal barrel, the through holes II on the upper part of the high-pressure water / hot air pipe are directed upward, and the through holes II on the lower part of the high-pressure water / hot air pipe are directed downward, so that the water or hot air sprayed through the high-pressure water / hot air pipe covers the filter cloth in the longitudinal direction of the barrel wall of the centrifugal barrel.

[0012] Further, the diameter of the through holes II is about 0.5-1.0 mm.

[0013] Further, the cover is provided with an up-and-down movable stirring paddle and a lifting brush for brushing the barrel wall of the centrifugal barrel, the stirring paddle is driven by a driving motor II, and the lifting brush is driven by a driving assembly to reciprocate in the longitudinal direction of the centrifugal barrel and rotate in the horizontal direction.

[0014] Further, the stirring paddle comprises a detachable stirring rod and a stirring head, and two stirring paddles are symmetrically arranged on the cover.

[0015] Further, the end of the stirring head is 20-50 mm away from the filter cloth.

[0016] Further, the cover is provided with a backwashing spray head, and a sight glass is further arranged on the cover.

[0017] Further, the filter cloth has a filtering precision of 0.1-2000 microns.

[0018] Further, the roughness of the inner wall and the bottom surface of the centrifugal barrel is less than 1Ra, and the included angle between the bottom of the centrifugal barrel and the horizontal plane is 10-30 degrees.

[0019] The beneficial effects of the present application are as follows:

[0020] Firstly, the present application discloses a micro-nano powder washing and dispersing filter device with a new structure, wherein a filter cloth is arranged on the inner wall of the centrifugal barrel, and the filter cloth is arranged only on the inner wall of the centrifugal barrel, and the bottom of the centrifugal barrel is a smooth arc-shaped bottom surface, so that the filtrate is discharged only along the inner wall of the centrifugal barrel during centrifugal filtration.

[0021] The utility model discloses a more optimal structure, still including detachable cover, and the cover still is connected with inlet pipe and high pressure water / hot -blast pipe, and a plurality of through -hole II are seted up on high pressure water / hot -blast pipe, and through -hole II is towards filter cloth, and the device can be washed to filter cloth when using, and the high pressure water is passed into, avoids the micro -nanometer powder to gather, to agglomerate in the vicinity of filter cloth, influences product quality, or the hot -blast (or hot steam) is passed into high pressure water / hot -blast pipe, realizes the blowing of the micro -nanometer powder that adheres on filter cloth or the drying of micro -nanometer powder, or the device after using is cleaned, dries, and is convenient for next time use. Such structure can realize the deep cleaning of residual powder on filter cloth, automatic cleaning, greatly saves the time of replacing and cleaning filter bag when batch production, and improves product rate simultaneously.

[0022] Three, the utility model discloses a more optimal one of the embodiment of micro -nanometer powder washing dispersion filter device, and high pressure water / hot -blast pipe stretches into centrifugal bucket lower part, and high pressure water / hot -blast pipe is connected high pressure water pipe or clean hot -blast pipe (steam pipe) away from centrifugal bucket end, and the through -hole II of high pressure water / hot -blast pipe upper part is upwards, and the through -hole II of lower part is downwards, guarantees the water or hot -blast that sprays through high pressure water / hot -blast pipe covers the filter cloth on centrifugal bucket barrel wall longitudinal, reaches the more optimal washing, drying effect. Through many times trial, and the aperture of through -hole II is seted up as 0.5~1.0mm, and can satisfy the washing, drying demand of most micro -nanometer powder.

[0023] Four, the utility model discloses a more optimal one of the embodiment of micro -nanometer powder washing dispersion filter device, and the cover is installed with the stirring paddle that can move up and down and is used for the lifting brush of the brush washing centrifugal bucket barrel wall, and the stirring paddle is driven through drive motor II, and the lifting brush is driven its reciprocating motion, horizontal direction rotation in centrifugal bucket longitudinal through drive assembly, and it is more convenient to realize the automatic process of soaking, washing, dispersion, filtering. The stirring paddle that can move up and down can be applicable to the washing of different material quantity's micro -nanometer powder, and the lifting brush can reciprocate and brush wash, and can disturb the micro -nanometer powder near filter cloth, avoids the powder to gather near filter cloth, influences normal filtration and product quality, and the lifting brush can also rotate in horizontal direction, and when not needing to disturb filter cloth surface material, can rotate lifting brush, and the operation is simple.

[0024] Five, the utility model discloses a stirring paddle includes detachable stirring rod and stirring head, and the stirring blade material of stirring head can select rubber strip, silica gel strip, polytetrafluoroethylene strip and so on different hardness and rigidity material according to demand. When practical application, the different specifications of micro -nanometer powder washing dispersion filter device can be designed according to the processing amount of material, and then the stirring paddle of proper number is selected and designed according to the specification of device. In the scheme, preferably, the stirring paddle includes two, and two stirring paddles are symmetrically arranged on the cover. The end of stirring head is preferably 20~50mm from filter cloth.

[0025] Six, in the utility model, the cover body is equipped with backflushing shower head, the cover body is also installed with sight glass, is used for observing the state of material and mechanism in device, backflushing shower head connects pure water supply pipe, can realize self-cleaning of machine cover and sight glass, reaches green environmental protection requirement. Backflushing shower head can also realize the absorption of volatile solvent and dust.

[0026] Seven, in the utility model, the filter cloth is detachably connected and installed with the centrifugal barrel, the filter cloth is made of polypropylene, polyester, polytetrafluoroethylene or other materials according to the material properties (such as viscosity, solid content, granularity, etc.), and the pore size of the filter cloth is preferably 0.1-2000 μm.

[0027] Eight, in the utility model, the centrifugal barrel inner wall needs to be polished, so that the roughness of the inner wall and bottom surface of the centrifugal barrel is less than 1Ra, the included angle between the centrifugal barrel bottom and horizontal plane is 10-30 °, the material at the bottom is ensured to slide to the filter cloth on the barrel wall under centrifugal force, the lowest end of the barrel bottom center is designed as a horizontal plane, and is smoothly connected with the side wall arc chamfer of the centrifugal barrel, to prevent material accumulation. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 It is the structure schematic view of the micro-nano powder washing, dispersing and filtering device in embodiment 1.

[0029] Figure 2 It is the three-dimensional structure schematic view of another embodiment of the micro-nano powder washing, dispersing and filtering device.

[0030] Figure 3 It is the front view of Figure 2 .

[0031] Figure 4 It is the top view of Figure 2 .

[0032] Figure 5 It is the A-A sectional view of Figure 4 .

[0033] Figure 6 It is the enlarged view of A part of Figure 5 .

[0034] Figure 7 It is the local enlarged view of high-pressure water / heat air pipe.

[0035] Figure 8 It is the structure schematic view of one embodiment of filter cloth quick-mounting assembly.

[0036] Wherein, 1, outer barrel; 2, centrifugal barrel; 3, through hole I; 4, filter cloth; 5, transmission assembly; 6, drive motor I; 7, discharge port; 8, liquid discharge port; 9, cover; 10, feed pipe; 11, high pressure water / hot air pipe; 12, through hole II; 13, stirring paddle; 14, lifting brush; 15, drive motor II; 16, drive assembly; 17, backwash spray head; 18, sight glass; 19, support seat; 20, locking piece; 21, filter cloth quick mounting assembly; 13.1, stirring rod; 13.2, stirring head; 21.1, quick mounting bolt; 21.2, bottom ring; 21.3, liquid baffle. DETAILED DESCRIPTION

[0037] The utility model will be further described in detail in connection with the embodiments, but the implementation of the utility model is not limited to this.

[0038] Example 1

[0039] This embodiment is the most basic implementation, a kind of micro-nano powder washing dispersion filter device, it is related to preparation chemical new material, food medicine, electronic material and powder equipment technical field, refer to Figure 1 , including outer barrel 1 and centrifugal barrel 2, a plurality of through holes I 3 are set on the barrel wall of centrifugal barrel 2, filter cloth 4 is mounted on the inner wall of centrifugal barrel 2, the bottom of centrifugal barrel 2 is smooth arc bottom surface, the bottom center of centrifugal barrel 2 is equipped with discharge port 7, centrifugal barrel 2 bottom is connected with drive motor I 6 by transmission assembly 5 passing through outer barrel 1, drive motor I 6 drives centrifugal barrel 2 to rotate, and outer barrel 1 bottom is equipped with liquid discharge port 8.

[0040] The micro-nano powder washing dispersion filter device can be used for the washing, dispersion and filtration of micro-nano powder with a particle size of 100 nm to 100 μm, and has good washing and dispersion effect, and rarely has the problem of agglomeration and hardening.

[0041] Example 2

[0042] This embodiment is a further optimization of example 1, the difference lies in that it further comprises a detachable cover 9, refer to Figure 2 , 7 The cover 9 is further connected with a feed pipe 10 and a high-pressure water / hot air pipe 11, a plurality of through holes II 12 are formed in the high-pressure water / hot air pipe 11, and the through holes II 12 are directed towards the filter cloth 4.

[0043] The high-pressure water / hot air pipe 11 is connected with a high-pressure water supply pipe and a hot air supply pipe respectively, and valves are arranged on the high-pressure water supply pipe and the hot air supply pipe, so that high-pressure water or clean hot air can be introduced into the micro-nano powder washing dispersion filter device by switching the valves on the pipes, and the high-pressure water or hot air through holes II 12 spray towards the filter cloth 4 close to the inner wall of the centrifugal barrel 2, so as to realize the timely cleaning and drying of the filter cloth 4 and the inner wall of the centrifugal barrel 2 in the device.

[0044] Example 3

[0045] Compared with Embodiment 2, the difference in this embodiment is that the high-pressure water / hot air pipe 11 extends into the lower part of the centrifuge tank 2, and the through hole II 12 at the upper part of the high-pressure water / hot air pipe 11 faces upward; the through hole II 12 at the lower part faces downward, as shown in the reference. Figure 7 Water or hot air sprayed through the high-pressure water / hot air pipe 11 covers the filter cloth 4 on the longitudinal side of the centrifuge barrel 2.

[0046] Example 4

[0047] Compared with Examples 1 to 3, the difference in this embodiment is that the pore diameter of the through hole II 12 is preferably set to 0.5~1.0mm, which can meet the washing and drying requirements of most micro and nano powders.

[0048] Example 5

[0049] Compared with Examples 1-4, the difference in this embodiment is that the cover 9 is equipped with a vertically movable stirring paddle 13 and a lifting brush 14 for scrubbing the walls of the centrifuge tank 2. (See reference...) Figures 2 to 5 The stirring paddle 13 is driven by the drive motor II 15, and the lifting brush 14 is driven by the drive assembly 16 to reciprocate in the longitudinal direction and rotate in the horizontal direction in the centrifuge tank 2.

[0050] In this embodiment, the up-and-down moving stirring paddle 13 is suitable for washing micro-nano powders of different material amounts. The lifting brush 14 can reciprocate up and down to brush, which can agitate the micro-nano powders near the filter cloth 4, preventing the powders from agglomerating near the filter cloth 4 and affecting normal filtration and product quality. The lifting brush 14 can also rotate in the horizontal direction. When it is not necessary to agitate the material on the surface of the filter cloth 4, the lifting brush 14 can be rotated to prevent the brush head of the lifting brush 14 from contacting the filter cloth 4, making operation simple.

[0051] Example 6

[0052] The difference between this embodiment and embodiments 1-5 is that, in reference... Figure 5 The stirring paddle 13 includes a detachable stirring rod 13.1 and a stirring head 13.2. The stirring blades of the stirring head 13.2 can be made of materials with different hardness and rigidity, such as rubber strips, silicone strips, and polytetrafluoroethylene strips, depending on the requirements. In this embodiment, there are two stirring paddles 13, which are symmetrically arranged on the cover 9.

[0053] Example 7

[0054] Compared with Examples 1 to 6, the difference in this embodiment is that the distance between the end of the stirring head 13.2 and the filter cloth 4 should be 20 to 50 mm, so as to ensure the stirring effect without affecting the normal operation of the stirring head 13.2.

[0055] Example 8

[0056] The difference between the embodiment and the embodiments 1-7 is that the cover 9 is provided with a backwashing spray head 17, and the cover 9 is further provided with a sight glass 18. Figures 2 to 5 The backwashing spray head 17 is connected with a pure water supply pipe, so that the cover 9 and the observation sight glass 18 can be automatically cleaned, and the green environmental protection requirement is achieved. In addition, the backwashing spray head 17 can also be used for absorbing volatile solvents and dust.

[0057] Embodiment 9

[0058] The difference between the embodiment and the embodiments 1-8 is that the filtering precision of the filter cloth 4 is preferably controlled to be 0.1-2000 μm.

[0059] Embodiment 10

[0060] The difference between the embodiment and the embodiments 1-9 is that the roughness of the inner wall and the bottom surface of the centrifugal barrel 2 is less than 1 Ra, the inner wall of the centrifugal barrel 2 needs to be polished to make the inner wall and the bottom surface of the centrifugal barrel 2 smooth, the included angle between the barrel bottom of the centrifugal barrel 2 and the horizontal plane is 10-30°, so as to ensure that the material at the bottom slides to the filter cloth 4 at the barrel wall under the centrifugal force, and the lowest end of the barrel bottom center is designed as a horizontal plane and is smoothly connected with the arc chamfer of the side wall of the centrifugal barrel 2, so as to prevent material accumulation.

[0061] Embodiment 11

[0062] In order to facilitate the public to understand the scheme, the embodiment takes a relatively optimal micro-nano powder washing, dispersing and filtering device as an example to further illustrate the scheme.

[0063] The micro-nano powder washing, dispersing and filtering device comprises an outer barrel 1, a centrifugal barrel 2 and a detachable cover 9. Figures 2 to 7 The device can automatically wash, disperse, filter, clean and dry the micro-nano powder with a size of 100 nm-100 μm.

[0064] In the embodiment, a plurality of through holes I 3 are formed in the barrel wall of the centrifugal barrel 2, and a filter cloth 4 is mounted next to the inner wall of the centrifugal barrel 2. The barrel bottom of the centrifugal barrel 2 is a smooth arc bottom surface. The centrifugal barrel 2 is connected with a driving motor I 6 through a transmission assembly 5 penetrating through the outer barrel 1. The driving motor I 6 drives the centrifugal barrel 2 to rotate. The centrifugal barrel 2 is provided with a discharge port 7 at the bottom. The installation position of a discharge driving mechanism can be determined according to specific conditions beside the discharge port 7. The outer barrel 1 is provided with a liquid discharge port 8 at the bottom. The cover 9 is further connected with a feeding pipe 10 and a high-pressure water / hot air pipe 11. A plurality of through holes II 12 are formed in the high-pressure water / hot air pipe 11, and the through holes II 12 face the filter cloth 4.

[0065] Valves are arranged on the high-pressure water supply pipe and the hot air supply pipe, and high-pressure water or clean hot air is supplied to the micro-nano powder washing, dispersing and filtering device by switching the valves.

[0066] In this embodiment, the high-pressure water / hot air pipe 11 extends into the lower part of the centrifugal barrel 2, and the through holes II 12 on the upper part of the high-pressure water / hot air pipe 11 face upwards; the through holes II 12 on the lower part face downwards, and the water or hot air sprayed through the high-pressure water / hot air pipe 11 covers the filter cloth 4 on the longitudinal wall of the centrifugal barrel 2. The diameter of the through holes II 12 is 0.5 mm.

[0067] In this embodiment, the cover 9 and the outer barrel 1 are detachable. One side of the cover 9 is connected to the outer barrel 1 through a hinge, which is preferably a hydraulic flip cover mechanism, and can realize automatic flip cover of 0-120°; or the cover 9 and the outer barrel 1 are opened and closed through multiple locking pieces 20.

[0068] In this embodiment, the cover 9 is provided with an up-and-down movable stirring paddle 13 and a lifting brush 14 for brushing the barrel wall of the centrifugal barrel 2. The lifting brush 14 is driven by a driving assembly 16 to reciprocate in the longitudinal direction of the centrifugal barrel 2 and rotate in the horizontal direction. The stirring paddle 13 includes a detachable stirring rod 13.1 and a stirring head 13.2. Two stirring paddles 13 are symmetrically arranged on the cover 9, and the two stirring paddles 13 are respectively driven to rotate by two driving motors II 15. The driving motor II 15 is a variable frequency speed regulating motor. The stirring motor lifting device drives the stirring head 13.2 to insert into the powder for stirring and dispersing. According to the properties of the powder such as viscosity, bulk density, hardness, batch size, the stirring head 13.2 can selectively install stirring blades of different materials and size specifications to match the material properties for optimal soaking, stirring and dispersing of the material.

[0069] In this embodiment, the end of the stirring head 13.2 is 20 mm away from the filter cloth 4.

[0070] In this embodiment, the cover 9 is provided with a backwashing spray head 17, and a sight glass 18 is also arranged on the cover 9.

[0071] In this embodiment, the filter cloth 4 has a filtering accuracy of 0.1 μm.

[0072] In this embodiment, the roughness of the inner wall and the bottom surface of the centrifugal barrel 2 is less than 1 Ra, and the included angle between the bottom of the centrifugal barrel 2 and the horizontal plane is 10°-30°.

[0073] In use, taking the washing, dispersion, and filtration of micron spherical silver powder as an example, the silver powder has a solid content of 50% to 80%, contains 5% to 20% of nitrate and organic impurities, and has a particle size D10 of 0.5 to 1.5 μm, a D50 of 1.5 to 5 μm, and a D90 of 3.0 to 7 μm, a wet-state bulk density of 1.5 to 2.5 g / mL, a pH of 1 to 3, and a conductivity of 40 ms / cm. The micro-nano powder comprises the following steps:

[0074] Step one: referring to Figure 8 , a filter cloth 4 with a pore size of 10 μm is selected, and the filter cloth 4 is inserted into a mounting groove in the inner wall of a centrifugal barrel 2 through a filter cloth quick-mounting assembly 21. The filter cloth quick-mounting assembly 21 has a structure as shown in Figure 8 , including a quick-mounting bolt 21.1, a bottom ring 21.2, and a liquid blocking plate 21.3. After mounting, the filter cloth 4 is flatly attached to the inner wall of the centrifugal barrel 2. Blades made of polytetrafluoroethylene and silica gel are respectively installed on the stirring heads 13.2 of two drive motors Ⅱ 15, and the stirring paddles 13 are respectively lowered to a certain height, so that the stirring heads 13.2 of the two stirring paddles 13 are respectively 20 mm and 100 mm away from the bottom of the centrifugal barrel 2. The discharge port 7 is closed, the cover 9 is closed, and the valve on the feed pipe 10 and the liquid discharge port 8 are opened.

[0075] Step two: the wet-state powder material is pumped into the centrifugal barrel 2 from the feed pipe 10, and the filling volume reaches 70% of the total capacity of the centrifugal barrel 2. The speed of the drive motor I 6 is set to 500 rpm, and the drive motor I 6 is started to separate the wet powder solid-liquid. After about 3 min, the liquid discharge speed of the liquid discharge port 8 slows down, and the drive motor I 6 is turned off at this time.

[0076] Step three: the high-pressure water / heat gas pipe 11 is opened, and the washing liquid (connected to the high-pressure water pipe) is switched to the liquid, that is, the valve on the high-pressure water supply pipe connected to the high-pressure water / heat gas pipe 11 is opened. Pure water is used as the washing liquid, the drive motor I 6 is started, and the centrifugal barrel 2 is kept at a speed of 10 rpm. A small amount of silver powder attached to the filter cloth 4 is washed into the bottom of the centrifugal barrel 2 by the pure water sprayed by the high-pressure water / heat gas pipe 11. At the same time, pure water is added through the feed pipe 10. When the volume of the material in the centrifugal barrel 2 reaches 50% to 70%, the water supply is stopped, the centrifugal barrel 2 is stopped, the speed of the drive motor Ⅱ 15 is adjusted to 300 rpm, and the drive motor Ⅱ 15 is started. The powder material is stirred, dispersed, and soaked for 3 min.

[0077] In actual application, a spray head can be added at the through hole Ⅱ 12 according to needs.

[0078] Step four: after the stirring and dispersion are completed, the drive motor Ⅱ 15 is stopped, the speed of the drive motor I 6 is adjusted to 1000 rpm, and the drive motor I 6 is started. After 2 min, the liquid discharge speed of the liquid discharge port 8 slows down, and the drive motor I 6 is stopped.

[0079] Step five: repeat steps three to four, soak, stir, centrifuge 5 times, and stop washing when the filtrate meets the requirements;

[0080] Step six: after the washed powder is centrifuged at 1000 rpm for 2 min to remove water, the discharge port 7 is opened, the filter cake after drying is discharged from the centrifugal barrel 2, the driving motor I 6 is started to keep the centrifugal barrel 2 at 10 rpm, the lifting brush 14 is slowly lowered, the brush head is kept in contact with the filter cloth 4, and the residual powder on the filter cloth 4 is brushed to the bottom of the barrel; the powder is transferred to the drying equipment for drying;

[0081] Step seven: keep the centrifugal barrel 250 rpm running at low speed, open the high-pressure pump and corresponding valve connected to the high-pressure water supply pipe of the high-pressure water / heat air pipe 11, use pure water to spray and wash the filter bag, slowly lower the lifting brush 14 to keep the brush head in contact with the filter cloth 4, wash the filter bag for 1 min under the action of the washing liquid and the lifting brush 14, and then switch the high-pressure water / heat air pipe 11 to the hot air mode, i.e. close the high-pressure pump and corresponding valve connected to the high-pressure water supply pipe, open the valve on the hot air supply pipe, and use high-pressure hot air to quickly dry the filter bag within 3 min.

[0082] After the silver powder is dispersed, washed, and filtered, the silver mud filter cake is loose after drying, and there is no caking phenomenon. The collection rate of the dried silver powder reaches 99.7%, and after pulverization, the particle size D10 is 0.5-1.1 μm, D50 is 1.5-2.0 μm, D90 is 3.0-3.5 μm, the bulk density is 2.8 g / mL, and the monitoring nitrate content is <20 ppm. The silver powder treated by the device of the embodiment has higher yield and can reach electronic grade in purity. The device is convenient to operate, and can be automatically cleaned and dried, saving time and effort. The cleaning and drying device is convenient for next use.

Claims

1. A micro / nano powder washing, dispersing, and filtering device, characterized in that: It comprises an outer barrel (1) and a centrifugal barrel (2), a plurality of through holes I (3) are arranged on the barrel wall of the centrifugal barrel (2), a filter cloth (4) is arranged on the inner wall of the centrifugal barrel (2) in close proximity, the bottom of the centrifugal barrel (2) is a smooth arc bottom surface, a discharge port (7) is arranged at the center of the bottom of the centrifugal barrel (2), the bottom of the centrifugal barrel (2) is connected with a driving motor I (6) through a transmission assembly (5) penetrating through the outer barrel (1), the driving motor I (6) drives the centrifugal barrel (2) to rotate, and the bottom of the outer barrel (1) is provided with a liquid discharge port (8).

2. The micro-nano powder washing, dispersing and filtering device according to claim 1, characterized in that: It also comprises a detachable cover body (9), a feeding pipe (10) and a high-pressure water / hot air pipe (11) are further connected to the cover body (9), a plurality of through holes II (12) are arranged on the high-pressure water / hot air pipe (11), and the through holes II (12) are directed towards the filter cloth (4).

3. The micro-nano powder washing, dispersing and filtering device according to claim 2, characterized in that: The high-pressure water / hot air pipe (11) extends into the lower part of the centrifugal barrel (2), the through holes II (12) on the upper part of the high-pressure water / hot air pipe (11) are directed upwards, the through holes II (12) on the lower part are directed downwards, and the water or hot air sprayed through the high-pressure water / hot air pipe (11) covers the filter cloth (4) on the longitudinal barrel wall of the centrifugal barrel (2).

4. The micro-nano powder washing, dispersing and filtering device according to claim 3, characterized in that: The diameter of the through holes II (12) is 0.5-1.0 mm.

5. The micro-nano powder washing, dispersing and filtering device according to claim 2, characterized in that: The cover body (9) is provided with an up-and-down movable stirring paddle (13) and a lifting brush (14) for brushing the barrel wall of the centrifugal barrel (2), the stirring paddle (13) is driven by a driving motor II (15), and the lifting brush (14) is driven by a driving assembly (16) to reciprocate in the longitudinal direction of the centrifugal barrel (2) and rotate in the horizontal direction.

6. The micro-nano powder washing, dispersing and filtering device according to claim 2, characterized in that: The stirring paddle (13) comprises a detachable stirring rod (13.1) and a stirring head (13.2), and the stirring paddle (13) comprises two, and the two stirring paddles (13) are symmetrically arranged on the cover body (9).

7. The micro-nano powder washing, dispersing and filtering device according to claim 6, characterized in that: The end of the stirring head (13.2) is 20-50 mm away from the filter cloth (4).

8. The micro-nano powder washing, dispersing and filtering device according to claim 2, characterized in that: The cover body (9) is provided with a backwashing spray head (17), and a sight glass (18) is further arranged on the cover body (9).

9. The micro-nano powder washing, dispersing and filtering device according to claim 1, characterized in that: The filter precision of the filter cloth (4) is 0.1-2000 μm.

10. The micro-nano powder washing, dispersing and filtering device according to claim 1, characterized in that: The roughness of the inner wall and the bottom surface of the centrifugal barrel (2) is less than 1 Ra, and the included angle between the bottom of the centrifugal barrel (2) and the horizontal plane is 10-30°.

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