A micro-nanometer flaky silver powder preparation line

Abstract

The application provides a micro-nanometer flaky silver powder preparation line and relates to the technical field of silver powder preparation.The preparation line integrates the structures of a grinding and screening machine, a pneumatic washing and purifying kettle, a nitrogen generator, a nitrogen heater and the like in an integrated design, wherein the grinding and screening machine adopts a multi-layer design of a ball-milling and screening inner cylinder, a screening and collecting intermediate barrel and a heat-exchanging rotary driving outer barrel, so that the grinding of spherical silver powder and the screening of target flaky silver powder are simultaneously realized; the material mixing mechanism ensures the uniformity of the material mixing in the horizontal ball mill, shortens the ball milling time and reduces the over-milling loss; the pneumatic washing and purifying kettle realizes the dispersion washing of the material after the solid-liquid separation through negative pressure liquid extraction, reduces the phenomenon of hardening and uneven manual washing; and the nitrogen heating airflow drying realizes the fluidized drying of the flaky silver powder material, so that the technical problems of the batch quality fluctuation of the silver powder product caused by the stability problem of the ball milling process and the pollution of the grinding aid and the grinding ball to the target flaky silver powder in the ball milling process are solved.

Description

Technical Field

[0001] This invention relates to the field of flake silver powder preparation technology, and specifically to a micro / nano flake silver powder preparation line. Background Technology

[0002] Flake-shaped micro / nanomaterials, with their unique two-dimensional structure, exhibit irreplaceable advantages in numerous application fields. Metallic silver, in particular, stands out for its superior conductivity. Therefore, flake-shaped silver powder plays a crucial role in various fields such as microelectronics, flexible displays, and photovoltaics. Pastes made by combining this silver powder with organic carriers and binders are widely used in electronic components such as filters, thin-film switches, semiconductor chips, and touchscreens, as well as in the back silver electrodes of solar cells. During the formation of conductive coatings, silver pastes formulated with flake-shaped silver powder have larger surface and line contact areas between particles, and the stacking characteristics of the upper and lower flake structures result in denser conductive circuits. This allows flake-shaped silver powder to achieve high conductivity even with lower silver content, and the printed coating thickness is thinner, not only saving silver resources but also compensating for the limitations of spherical silver powder in applications.

[0003] Currently, mechanical ball milling, photo-induced methods, and chemical synthesis are the mainstream methods for preparing flake silver powder. Among them, mechanical ball milling is highly regarded due to its wide applicability and mass production capability. By controlling parameters such as the ball-to-particle ratio, milling aids, solid-liquid ratio, and milling time, mechanical ball milling further transforms spherical silver particles into flake silver powder. Numerous studies have explored the influence of various parameters on the performance of flake silver powder during mechanical ball milling, such as the selection of milling balls, the ball-to-particle ratio, and the rotation speed. By optimizing these parameters, flake silver powder with good performance can be obtained. Preparing highly dispersed spherical silver powder first through chemical precipitation, and then using mechanical ball milling technology to transform it into flake silver powder, is an effective preparation method. However, mechanical ball milling also faces some challenges in silver powder production. First, the stability of the ball milling process leads to batch quality fluctuations in silver powder products; second, the milling aids and milling balls added during the ball milling process may contaminate the silver powder, thus limiting the preparation of high-purity flake silver powder.

[0004] In view of this, it is necessary to develop a micro / nano sheet silver powder preparation line that can effectively ensure batch stability, low contamination, and high purity. Summary of the Invention

[0005] In view of the technical problems existing in the background art, the present invention provides a micro-nano flake silver powder preparation line, which adopts a mechanical ball milling and sieving structure to ensure batch stability, and uses a pneumatic purification and washing equipment to ensure the purity and dispersibility of flake silver.

[0006] This invention provides a micro / nano-sheet silver powder preparation line, which includes a ball powder slurry mixing tank, a grinding and screening machine, and a pneumatic washing and purification tank connected in sequence according to the material conveying direction;

[0007] The grinding disc screening machine includes a ball mill drive mechanism, a material mixing mechanism, and a ball mill rotating body;

[0008] The ball mill rotating body is tumblingly connected to the ball mill drive mechanism, and includes a ball mill screening inner cylinder, a screening and collection intermediate cylinder, and a heat exchange rotating drive outer cylinder arranged coaxially and sequentially from the inside to the outside along the radial direction;

[0009] The material mixing mechanism is rotatably connected to the ball mill rotating body and includes a mixing drive shaft with one end penetrating through the ball mill rotating body and extending into the inner cylinder of the ball mill screening cylinder, a mixing turner symmetrically arranged on the mixing drive shaft, and a mixing drive mechanism for driving the mixing drive shaft to rotate.

[0010] As a further improvement of the present invention, the grinding disc screening machine further includes a cleaning mechanism disposed at one end of the axial direction of the ball mill rotating body; the cleaning mechanism includes a cleaning rotating slip ring, a heat exchange liquid inlet valve, a material cleaning valve, and a waste cleaning valve;

[0011] One end of each of the heat exchange inlet valve, material cleaning valve, and waste cleaning valve is connected to the cleaning rotating ring, and the other end is connected to the heat exchange rotating drive outer barrel, the ball mill screening inner barrel, and the sieve collection intermediate barrel, respectively.

[0012] As a further improvement of the present invention, the grinding disc screening machine also includes a discharge mechanism disposed at the other end of the axial direction of the ball mill rotating body; the discharge mechanism includes a maintenance flange, a discharge rotary slip ring, a discharge valve, a waste valve, a slurry valve, and a heat exchange return valve;

[0013] One side of the maintenance flange is connected to the inner cylinder of the ball mill sieve, the intermediate sieve collection tank, and the outer cylinder of the heat exchange rotary drive, while the other side is connected to the slurry valve via a discharge rotary slip ring. The discharge valve, waste valve, and heat exchange return valve are all fixed on the maintenance flange. At the same time, the discharge valve is connected to the material space of the inner cylinder of the ball mill sieve; the waste valve is connected to the waste space formed by the inner cylinder of the ball mill sieve and the intermediate sieve collection tank; and the heat exchange return valve is connected to the heat exchange space formed by the intermediate sieve collection tank and the outer cylinder of the heat exchange rotary drive.

[0014] The slurry valve, discharge valve, and heat exchange return valve are respectively connected to the discharge rotary slip ring;

[0015] The feed inlet of the discharge valve is equipped with a ball separation plate.

[0016] As a further improvement of the present invention, the cleaning rotating slip ring includes a cleaning rotating moving ring and a cleaning rotating stationary ring that are rotatably connected to each other, and multiple cleaning outlets and multiple cleaning inlets respectively provided on the cleaning rotating moving ring and the cleaning rotating stationary ring.

[0017] The cleaning rotating moving ring and the cleaning rotating stationary ring are provided with a communicating rotating intermediate shaft hole;

[0018] The mixing drive shaft passes through the rotating intermediate shaft hole and is connected to the cleaning rotating slip ring.

[0019] As a further improvement of the present invention, the discharge rotating slip ring includes a discharge rotating moving ring and a discharge rotating stationary ring that are rotatably connected to each other, and a refrigerant inlet and a refrigerant outlet respectively provided on the discharge rotating moving ring and the discharge rotating stationary ring.

[0020] The discharge rotating moving ring and the discharge rotating stationary ring are provided with a connecting intermediate shaft hole;

[0021] The slurry valve is connected to the discharge rotary slip ring through the intermediate shaft hole.

[0022] As a further improvement of the present invention, the ball mill drive mechanism includes a rotary drive reducer, a rotary drive shaft, and a drive support roller connected in sequence; the drive support roller is rolledly connected to both ends of the ball mill rotating body in the axial direction.

[0023] As a further improvement of the present invention, the pneumatic washing purification vessel includes a purification vessel body, a sealed vessel cover and a solid-liquid separation plate respectively disposed on the top and inside of the purification vessel body;

[0024] The surface of the sealed autoclave lid is provided with a washing inlet, an ultrasonic generator, and a gas filter;

[0025] The bottom of the purification vessel is provided with a negative pressure liquid extraction port and a gas stirring port.

[0026] As a further improvement of the present invention, the micro / nano sheet silver powder preparation line also includes a refrigerator; the liquid outlet and liquid return end of the refrigerator are respectively connected to the cleaning mechanism and the discharge mechanism.

[0027] As a further improvement of the present invention, the micro / nano sheet silver powder preparation line also includes a washing solution storage tank, a vacuum pump, a nitrogen heater, and a nitrogen generator;

[0028] The negative pressure extraction port of the pneumatic washing and purification vessel is connected in sequence to the washing liquid storage tank and the vacuum pump;

[0029] The gas stirring port of the pneumatic washing and purification vessel is connected in sequence to a nitrogen heater and a nitrogen generator.

[0030] As a further improvement of the present invention, the micro / nano sheet silver powder preparation line also includes an ethanol supply machine;

[0031] The outlet of the ethanol supply machine is connected to the cleaning mechanism and the pneumatic washing and purification vessel, respectively.

[0032] The beneficial effects of this invention are:

[0033] The micro / nano flake silver powder preparation line provided by this invention integrates a grinding and sieving machine, a pneumatic washing and purification vessel, a nitrogen generator, and a nitrogen heater into a single integrated design. The grinding and sieving machine features a multi-layered design: a ball mill sieving inner cylinder, a sieving and collection intermediate cylinder, and a heat exchange rotating drive outer cylinder. This achieves simultaneous grinding of spherical silver powder into flakes and sieving of the target flake silver powder. Simultaneously, the material mixing mechanism ensures uniform mixing within the horizontal ball mill, shortening grinding time and reducing over-grinding losses. The pneumatic washing and purification vessel utilizes pneumatic and ultrasonic stirring to replace manual washing, achieving negative pressure liquid extraction and solid-liquid separation followed by material dispersion washing, reducing caking and unevenness issues associated with manual washing. Nitrogen-heated airflow drying achieves fluidized drying of the flake silver powder material. Based on this structural design, the overall solution addresses the technical problems of batch quality fluctuations in silver powder products caused by the instability of the ball milling process, as well as the contamination of the target flake silver powder by grinding aids and grinding balls during the ball milling process.

[0034] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and in order to make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described below. Attached Figure Description

[0035] To more clearly illustrate the technical solution of the present invention, the accompanying drawings used in the present invention will be briefly described below. Obviously, the drawings described below are merely some embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0036] Figure 1 This is a schematic diagram of the micro / nano sheet silver powder preparation line provided in an embodiment of the present invention;

[0037] Figure 2 This is a schematic diagram of the structure of the wire grinding and sieving machine for preparing micro / nano flake silver powder provided in an embodiment of the present invention;

[0038] Figure 3 This is a schematic diagram of the cleaning mechanism of the wire mill sieving machine for preparing micro / nano flake silver powder according to an embodiment of the present invention;

[0039] Figure 4 This is a schematic diagram of the material discharge mechanism of the wire mill sieve for preparing micro / nano flake silver powder according to an embodiment of the present invention;

[0040] Figure 5 This is a schematic diagram of the pneumatic washing and purification vessel of the micro / nano sheet silver powder preparation line provided in the embodiments of the present invention;

[0041] Explanation of reference numerals in the attached figures:

[0042] 1. Powder mixing tank; 2. Grinding and screening machine; 3. Ethanol supply machine; 4. Refrigeration unit; 5. Waste recovery tank; 6. Pneumatic washing and purification tank; 7. Washing liquid storage tank; 8. Vacuum pump; 9. Nitrogen generator; 10. Nitrogen heater;

[0043] 21. Adjustable base; 22. Ball mill drive mechanism; 23. Material mixing mechanism; 24. Ball mill rotating body; 25. Cleaning mechanism; 26. Discharge mechanism;

[0044] 61. Sealed vessel lid; 62. Purification vessel body; 63. Solid-liquid separation plate; 64. Support; 65. Washing inlet; 66. Ultrasonic generator; 67. Gas filter; 68. Negative pressure extraction port; 69. Gas stirring port;

[0045] 211. Fixed foundation; 212. Double-sided rotating hinge; 213. Left support expansion joint; 214. Right support expansion joint; 215. Workbench; 216. High-position support;

[0046] 221. Rotary drive reducer; 222. Rotary drive shaft; 223. Drive support roller;

[0047] 231. Mixing drive reducer; 232. Bearing housing; 233. Mixing drive shaft; 234. Mixing turner;

[0048] 241. Inner cylinder of ball mill screening; 242. Intermediate sieve collection cylinder; 243. Outer cylinder of heat exchange rotary drive; 244. Cleaning rotary support end cover; 245. Discharge rotary support end cover;

[0049] 251. Cleaning rotary slip ring; 252. Heat exchanger inlet valve; 253. Material cleaning valve; 254. Waste cleaning valve

[0050] 261. Inspection flange; 262. Discharge rotary slip ring; 263. Discharge valve; 264. Waste valve; 265. Slurry valve; 266. Heat exchange return valve; 267. Ball separator plate;

[0051] 251-1 Cleaning the rotating moving ring; 251-2 Cleaning the rotating stationary ring; 251-3 Rotating intermediate shaft hole; 251-4 Multi-channel cleaning outlet; 251-5 Multi-channel cleaning inlet;

[0052] 262-1, Discharge rotating moving ring; 262-2, Discharge rotating stationary ring; 262-3, Intermediate shaft hole; 262-4, Refrigerant outlet; 262-5, Refrigerant inlet. Detailed Implementation

[0053] The embodiments of the technical solution of the present invention will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the technical solution of the present invention and are therefore intended to limit the scope of protection of the present invention.

[0054] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the invention, are intended to cover non-exclusive inclusion.

[0055] In the description of the embodiments of this invention, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this invention, "multiple" means two or more, unless otherwise explicitly defined.

[0056] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0057] In the description of the embodiments of this invention, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0058] In the description of the embodiments of the present invention, the term "multiple" refers to two or more (including two), similarly, "multiple groups" refers to two or more (including two groups), and "multiple pieces" refers to two or more (including two pieces).

[0059] In the description of the embodiments of the present invention, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present invention and simplifying the description, and are not intended to 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 embodiments of the present invention.

[0060] In the description of the embodiments of the present invention, unless otherwise explicitly specified and limited, the technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention according to the specific circumstances.

[0061] To address the instability issues of traditional ball milling processes that lead to batch quality fluctuations in silver powder products, as well as the technical problems of contamination of the target flake silver powder by grinding aids and grinding balls during the ball milling process, this invention provides a micro / nano flake silver powder preparation line. It employs a mechanical ball milling and sieving structure to ensure batch stability, and uses pneumatic purification and washing equipment to ensure the purity and dispersibility of the flake silver.

[0062] Example 1

[0063] Please refer to Figure 1 As shown, the micro / nano flake silver powder preparation line provided by the present invention mainly includes a ball powder mixing tank 1, a grinding and screening machine 2, an ethanol supply machine 3, a refrigerator 4, a waste recovery tank 5, a pneumatic washing and purification tank 6, a washing liquid storage tank 7, a vacuum pump 8, a nitrogen generator 9, and a nitrogen heater 10.

[0064] Please refer to Figure 2 As shown, the grinding disc screening machine 2 is composed of an adjustable base 21, a ball mill drive mechanism 22, a material mixing mechanism 23, a ball mill rotating body 24, a cleaning mechanism 25, and a discharge mechanism 26.

[0065] The adjustable base 21 includes a fixed base 211, a double-sided rotating hinge 212, a left support telescopic member 213, a right support telescopic member 214, a work surface 215, and a high-position support 216.

[0066] The ball mill drive mechanism 22 includes a rotary drive reducer 221, a rotary transmission shaft 222, and a transmission support roller 223.

[0067] The material mixing mechanism 23 includes a mixing drive reducer 231, a bearing seat 232, a mixing drive shaft 233, and a mixing turner 234.

[0068] The ball mill rotating body 24 includes a ball mill screening inner cylinder 241, a screening and collection intermediate cylinder 242, a heat exchange rotating drive outer cylinder 243, a cleaning rotating support end cover 244, and a discharge rotating support end cover 245.

[0069] The cleaning mechanism 25 includes a cleaning rotary slip ring 251, a heat exchange liquid inlet valve 252, a material cleaning valve 253, and a waste cleaning valve 254.

[0070] The discharge mechanism 26 includes an inspection flange 261, a discharge rotary slip ring 262, a discharge valve 263, a waste valve 264, a slurry valve 265, and a heat exchange return valve 266.

[0071] Please refer to Figure 3 As shown, the cleaning rotating slip ring 251 includes a cleaning rotating moving ring 251-1, a cleaning rotating stationary ring 251-2, a rotating intermediate shaft hole 251-3, a multi-channel cleaning liquid outlet 251-4, and a multi-channel cleaning liquid inlet 251-5.

[0072] Please refer to Figure 4 As shown, the discharge rotating slip ring 262 includes a discharge rotating moving ring 262-1, a discharge rotating stationary ring 262-2, an intermediate shaft hole 262-3, a refrigerant outlet 262-4, and a refrigerant inlet 262-5.

[0073] The workbench 215 is connected to the fixed foundation 211 via a double-sided rotating hinge 212. A left support telescopic device 213 and a right support telescopic device 214 are installed between the left and right sides of the workbench 215 and the fixed foundation 211. The high-position bracket 216 is fixed at the middle position on the right side of the workbench 215. The output end of the rotary drive reducer 221 is connected to the rotary transmission shaft 222. Two transmission support rollers 223 are installed at the front and rear of the rotary transmission shaft 222.

[0074] The ball mill drive mechanism 22 is symmetrically arranged and fixed on the front and rear sides of the worktable 215. The ball mill rotating body 24 has a ball mill screening inner cylinder 241, a screening and collection intermediate cylinder 242, and a heat exchange rotating drive outer cylinder 243 arranged concentrically, with its two ends installed on the cleaning rotating support end cover 244 and the discharge rotating support end cover 245, respectively.

[0075] The ball mill rotating body 24 is rolled on the four-point transmission support roller 223 of the ball mill drive mechanism 22 via the cleaning rotating support end cover 244 and the discharge rotating support end cover 245; the cleaning rotating slip ring 251, heat exchange liquid inlet valve 252, material cleaning valve 253 and waste cleaning valve 254 of the cleaning mechanism 25 are installed on one side of the cleaning rotating support end cover 244.

[0076] The mixing drive reducer 231 and bearing seat 232 of the material mixing mechanism 23 are fixed on the high-level bracket 216. One end of the mixing drive shaft 233 is connected to the output end of the mixing drive reducer 231, and the other end passes through the rotating intermediate shaft hole 251-3 to assemble the cleaning rotating slip ring 251 and extends into the inner cylinder 241 of the ball mill screen. The mixing turner 234 is symmetrically arranged on the surface.

[0077] The heat exchange inlet valve 252, material cleaning valve 253, and waste cleaning valve 254 are connected at one end to the multi-way cleaning outlet 251-4 on the cleaning rotating ring 251-1 through pipelines, and at the other end to the heat exchange rotating drive outer barrel 243, the ball mill screening inner barrel 241, and the sieve collection intermediate barrel 242, respectively.

[0078] The discharge rotary support end cover 245 is detachably bolted to the discharge mechanism 26 via the maintenance flange 261. One side of the maintenance flange 261 is connected to the ball mill screening inner cylinder 241, the screening collection intermediate tank 242, and the heat exchange rotary drive outer tank 243, and the other side is connected to the slurry valve 265 via the discharge rotary slip ring 262.

[0079] The discharge valve 263, waste valve 264, and heat exchange return valve 266 are all fixed on the maintenance flange 261; at the same time, the discharge valve 263 is connected to the material space of the ball mill screening inner cylinder 241; the waste valve 264 is connected to the waste space formed by the ball mill screening inner cylinder 241 and the intermediate screening collection tank 242; and the heat exchange return valve 266 is connected to the heat exchange space formed by the intermediate screening collection tank 242 and the heat exchange rotary drive outer tank 243.

[0080] In short, the discharge valve 263 is connected to the inner cylinder 241 of the ball mill sieve; the waste valve 264 is connected to the intermediate sieve collection tank 242; and the heat exchange return valve 266 is connected to the outer heat exchange rotary drive tank 243.

[0081] The slurry valve 265 is assembled and installed in the intermediate shaft hole 262-3 of the discharge rotary slip ring 262 through a pipeline. The heat exchange return liquid valve 266 is connected to the refrigerant inlet 262-5 of the discharge rotary moving ring 262-1 through a pipeline. A ball material separation plate 267 is provided on the discharge rotary support end cover 245 at the feed end of the discharge valve 263.

[0082] Please refer to Figure 5As shown, the pneumatic washing and purification vessel 6 is composed of a sealed vessel cover 61, a purification vessel body 62, a solid-liquid separation plate 63, and a support 64.

[0083] The sealed kettle lid 61 has a washing inlet 65, an ultrasonic generator 66, and a gas filter 67 on its surface.

[0084] The bottom of the purification vessel 62 has a negative pressure liquid extraction port 68 and a gas stirring port 69, and the solid-liquid separation plate 63 is placed at the bottom end cap of the purification vessel 62.

[0085] In summary, the bottom discharge end of the ball powder slurry preparation vessel 1 is connected to the slurry valve 265 of the grinding disc sieve 2 via a pipeline valve; the liquid outlet end of the ethanol supply machine 3 is connected to the multi-way cleaning inlet 251-5 on the cleaning rotating stationary ring 251-2 of the cleaning rotating slip ring 251 of the grinding disc sieve 2 via a pipeline valve. The liquid outlet end of the ethanol supply machine 3 is also connected to the washing inlet 65 of the pneumatic washing purification vessel 6 via a pipeline valve.

[0086] The liquid outlet of the refrigeration unit 4 is connected to one of the multiple cleaning inlets 251-5 on the cleaning rotating stationary ring 251-2 of the cleaning rotating slip ring 251 of the grinding disc screen 2 via a pipeline valve; the liquid return of the refrigeration unit 4 is connected to the refrigerant outlet 262-4 on the discharge rotating stationary ring 262-2 of the discharge rotating slip ring 262 of the grinding disc screen 2 via a pipeline valve.

[0087] The waste valve 264 and discharge valve 263 of the grinding plate screening machine 2 are respectively connected to the washing inlet 65 of the waste recovery vessel 5 and the pneumatic washing and purification vessel 6.

[0088] The negative pressure extraction port 68 of the pneumatic washing and purification vessel 6 is connected to the washing liquid storage tank 7 and the vacuum pump 8 in sequence through pipeline valves. The gas stirring port 69 of the pneumatic washing and purification vessel 6 is connected to the nitrogen heater 10 and the nitrogen generator 9 in sequence through pipeline valves.

[0089] The working process of the micro / nano sheet silver powder preparation line provided by this invention is as follows:

[0090] First, a specified amount of grinding balls is added to the grinding disc screening machine 2. Then, the ball powder mixing tank 1 is started, and spherical silver powder particles, grinding aid and organic solvent are added to it. After stirring and mixing, the slurry to be ground is obtained.

[0091] When the refrigeration unit 4 is started, the heat exchange medium enters through the pipeline via the multi-way cleaning inlet 251-5 of the cleaning rotating stationary ring 251-2 and exits through the corresponding multi-way cleaning outlet 251-4 of the cleaning rotating moving ring 251-1. Then, it enters the heat exchange rotating drive outer tank 243 through the heat exchange inlet valve 252 to start the heat exchange function. The medium that has completed the heat exchange flows back to the refrigeration unit 4 through the heat exchange return valve 266, the refrigerant inlet 262-5 of the discharge rotating moving ring 262-1, and the refrigerant outlet 262-4 of the discharge rotating stationary ring 262-2.

[0092] The rotary drive reducer 221 of the ball mill drive mechanism 22 of the grinding disc screen 2 starts, and drives the four-point transmission support roller 223 to roll through the rotary transmission shaft 222; the four-point transmission support roller 223 drives the cleaning rotary support end cover 244 and the discharge rotary support end cover 245, thereby driving the ball mill rotating body 24 to rotate at a specified speed.

[0093] Simultaneously, the mixing drive reducer 231 of the material mixing mechanism 23 starts. Under the support of the bearing seat 232 and the cleaning rotating slip ring 251, the mixing drive shaft 233 drives the mixing turner 234 to rotate at a specified speed. During this process, the cleaning rotating moving ring 251-1 and the discharge rotating moving ring 262-1 of the cleaning rotating slip ring 251 and the discharge rotating slip ring 262, as well as the pipelines and valves connected to them, all rotate with the ball mill rotating body 24, while the cleaning rotating stationary ring 251-2, the discharge rotating stationary ring 262-2, and the pipelines connected to them remain stationary.

[0094] When the grinding disc screener 2 enters the working state, the ball powder mixing tank 1 begins to feed the material into the inner cylinder 241 of the ball mill rotating body 24 through the slurry valve 265 and the intermediate shaft hole 262-3 of the discharge rotary slip ring 262. As the material mixing mechanism 23 and the ball mill rotating body 24 rotate at different speeds, the material is ball-milled, uniformly mixed, and screened within the inner cylinder 241. During this process, extremely fine ball powder or flake powder passes through the inner cylinder 241 and enters the intermediate collection bucket 242 for collection, while larger ball powder flakes remain in the inner cylinder 241 after grinding.

[0095] After the designated working time, the ball mill drive mechanism 22 of the grinding disc screen 2 stops working, and the left support telescopic device 213 and the right support telescopic device 214 of the adjustable base 21 are started. Under the support of the double-sided rotating hinge 212, a certain discharge inclination angle of the worktable 215 is adjusted.

[0096] The waste valve 264 of the discharge mechanism 26 opens to discharge waste into the waste recovery vessel 5.

[0097] At the same time, the waste cleaning valve 254 of the cleaning mechanism 25 is opened; the ethanol supply machine 3 is started to realize the sieving and collection of waste in the intermediate tank 242 and emptying, and then the waste cleaning valve 254 and waste valve 264 are closed.

[0098] Open the discharge valve 263 of the discharge mechanism 26 and the material cleaning valve 253 of the cleaning mechanism 25. The ethanol supply machine 3 starts, and under the isolation effect of the ball-material separation plate 267, the target silver flakes are discharged into the pneumatic washing purification vessel 6 through the washing inlet 65, while the grinding balls remain in the grinding flake sieve machine 2. After the discharge is completed, the discharge valve 263 and the material cleaning valve 253 are closed, the refrigeration unit 4 is turned off, and the adjustable base 21 returns to its horizontal working state.

[0099] Vacuum pump 8 is started, and the target flake silver powder in the pneumatic washing purification vessel 6 completes solid-liquid separation on solid-liquid separation plate 63. The liquid enters the washing liquid storage tank 7 for storage, and vacuum pump 8 is turned off.

[0100] Ethanol feeder 3 starts, adding ethanol washing solution through washing inlet 65. Ultrasonic generator 66 and nitrogen generator 9 start. Nitrogen gas is evenly distributed through gas stirring port 69 and solid-liquid separation plate 63, combined with ultrasonic action, to achieve dynamic washing and ethanol purification of the target flake silver powder in pneumatic washing purification vessel 6. After washing, nitrogen generator 9 and ultrasonic generator 66 are turned off. Vacuum pump 8 is started for further washing solution separation, and then vacuum pump 8 is turned off.

[0101] Start the nitrogen generator 9 and nitrogen heater 10, and use nitrogen at a certain temperature to begin airflow drying of the target flake silver powder in the pneumatic washing and purification vessel 6. The dried airflow is discharged through the gas filter 67.

[0102] After the drying process is completed, first turn off the nitrogen heater 10 and then the nitrogen generator 9. Open the sealed lid 61 of the pneumatic washing and purification vessel 6 to obtain the final target flake silver powder.

[0103] In summary, this invention provides a micro / nano-scale silver powder preparation line, relating to the field of silver powder preparation technology. This preparation line integrates a grinding and sieving machine, a pneumatic washing and purification vessel, a nitrogen generator, a nitrogen heater, an ethanol supply unit, and a refrigerator into a single integrated design. The grinding and sieving machine employs a multi-layered design, consisting of a ball mill inner cylinder, a sieving and collection intermediate cylinder, and a heat exchange rotating drive outer cylinder, achieving simultaneous grinding of spherical silver powder and sieving of the target flaky silver powder. Simultaneously, the material mixing mechanism ensures uniform mixing within the horizontal ball mill, shortening grinding time and reducing over-grinding losses. The pneumatic washing and purification vessel utilizes pneumatic and ultrasonic stirring to replace manual washing, achieving negative pressure liquid extraction and solid-liquid separation followed by material dispersion washing, reducing caking and unevenness issues associated with manual washing. Nitrogen-heated airflow drying achieves fluidized drying of the flaky silver powder material. Based on the above structural design, this invention comprehensively solves the technical problems of batch quality fluctuations in silver powder products caused by the instability of the ball milling process, as well as the contamination of the target flaky silver powder by grinding aids and grinding balls during the ball milling process.

[0104] It should be noted that the present invention is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments that have the same structure and perform the same effects as the technical concept within the scope of the present invention are included within the scope of the present invention. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, without departing from the spirit of the present invention, are also included within the scope of the present invention.

Claims

1. A micro-nanoscale flaky silver powder preparation line, characterized in that, The mill sheet screening machine comprises a ball powder slurry mixing kettle, a mill sheet screening machine, and a pneumatic washing and purifying kettle connected in sequence in the material conveying direction. The mill sheet screening machine comprises a ball mill driving mechanism, a material mixing mechanism, and a ball mill rotating body. The ball mill rotating body is rollingly connected with the ball mill driving mechanism and comprises a ball mill screening inner cylinder, a screening and collecting middle barrel, and a heat exchange rotating driving outer barrel arranged coaxially and sequentially from inside to outside along the radial direction. The material mixing mechanism is rotationally connected with the ball mill rotating body and comprises a mixing driving shaft penetrating through the ball mill rotating body and extending into the interior of the ball mill screening inner cylinder, a mixing and turning device symmetrically arranged on the mixing driving shaft, and a mixing driving mechanism for driving the mixing driving shaft to rotate. The mill sheet screening machine further comprises a cleaning mechanism arranged at one axial end of the ball mill rotating body. The cleaning mechanism comprises a cleaning rotating slip ring and a heat exchange liquid inlet valve, a material cleaning valve, and a waste material cleaning valve, one end of which is connected with the cleaning rotating ring and the other end of which is respectively connected with the heat exchange rotating driving outer barrel, the ball mill screening inner cylinder, and the screening and collecting middle barrel. The mill sheet screening machine further comprises a discharging mechanism arranged at the other axial end of the ball mill rotating body. The discharging mechanism comprises a discharging rotating slip ring, a discharging valve, a waste material valve, a slurry valve, and a heat exchange liquid return valve. The discharging valve is communicated with the ball mill screening inner cylinder. The waste material valve is communicated with the screening and collecting middle barrel. The heat exchange liquid return valve is communicated with the heat exchange rotating driving outer barrel. The slurry valve, the discharging valve, and the heat exchange liquid return valve are respectively connected with the discharging rotating slip ring. The discharging valve is provided with a ball material separation plate at the feeding end. The cleaning rotating slip ring comprises a cleaning rotating ring, a cleaning rotating static ring, and a plurality of cleaning liquid outlets and a plurality of cleaning liquid inlets arranged on the cleaning rotating ring and the cleaning rotating static ring. The cleaning rotating ring and the cleaning rotating static ring are provided with a rotating intermediate shaft hole communicated therebetween.

2. The micro-nanoscale flaky silver powder preparation line according to claim 1, characterized in that, The mixing driving shaft penetrates through the rotating intermediate shaft hole and is connected with the cleaning rotating slip ring. 3.The micro-nanoscale flaky silver powder preparation line according to claim 1, characterized in that, The discharging rotating slip ring comprises a discharging rotating ring, a discharging rotating static ring, and a refrigerant liquid inlet and a refrigerant liquid outlet arranged on the discharging rotating ring and the discharging rotating static ring. The discharging rotating ring and the discharging rotating static ring are provided with an intermediate shaft hole communicated therebetween. The slurry valve penetrates through the intermediate shaft hole and is connected with the discharging rotating slip ring. 4.The micro-nanoscale flaky silver powder preparation line according to claim 1, characterized in that, The ball mill driving mechanism comprises a rotating driving speed reducer, a rotating transmission shaft, and a transmission support roller connected in sequence.

5. The micro-nanoscale silver flake production line according to claim 1, characterized in that, The transmission support roller is rollingly connected with the axial ends of the ball mill rotating body. The pneumatic washing and purifying kettle comprises a purifying kettle body and a sealing kettle cover and a solid-liquid separation plate arranged at the top and the interior of the purifying kettle body, respectively. The surface of the sealing kettle cover is provided with a washing feeding port, an ultrasonic generator, and a gas filter. The bottom of the purifying kettle body is provided with a negative pressure liquid pumping port and a gas stirring port. The micro-nano flaky silver powder preparation line further comprises a refrigerator, and the liquid outlet end and the liquid return end of the refrigerator are respectively communicated with the cleaning mechanism and the discharging mechanism. The micro-nano flaky silver powder preparation line further comprises a washing liquid storage tank, a vacuum pump, a nitrogen heater, and a nitrogen generator. The negative pressure liquid pumping port of the pneumatic washing and purifying kettle is sequentially connected with the washing liquid storage tank and the vacuum pump. The gas stirring port of the pneumatic washing purification kettle is connected with a nitrogen heater and a nitrogen generator in sequence.

6. The micro-nanoscale silver flake production line according to claim 1, characterized in that, The micro-nanometer flaky silver powder preparation line further comprises an ethanol feeder. The liquid outlet of the ethanol feeder is communicated with the cleaning mechanism and the pneumatic washing purification kettle respectively.

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