Preparation method and device of high-dispersion and wide-distribution silver powder

Abstract

The application relates to the technical field of silver powder preparation, in particular to a high-dispersion and wide-distribution silver powder preparation method and device, wherein the preparation device comprises a guide rail, a flushing system, an oven and a material mixing tank composed of an upper tank body and a movable lower seat body; the movable lower seat body can be separated from the upper tank body and sequentially moved to a flushing station below the flushing system along the guide rail to be flushed and to a heating station below the oven to be dried; a movable cleaning assembly is further connected to the guide rail and moved to the exact position below the upper tank body to flush the inside of the upper tank body. The material mixing tank composed of the upper tank body and the movable lower seat body can simultaneously complete the proportioning of silver amine solution A, dispersant solution B, surface active agent solution C and reducing liquid D, so that the work efficiency is greatly improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of silver powder preparation, in particular to a high-dispersion and wide-distribution silver powder preparation method and device. BACKGROUND

[0002] In the field of conductive paste for photovoltaics, controlling the shape or distribution of metal particles has always been a focus, which can greatly affect the long-term printability of the paste and the electrical properties of the film after sintering, and silver powder occupies an important application position.

[0003] Existing silver powder preparation often emphasizes its spherical shape, monodispersity, and narrow distribution, but the particle size of the prepared silver powder is often not well controlled. For example, patent CN 113658739 A discloses a composite spherical silver powder with controllable particle size distribution, which not only has a complex process, but also has poor sphericity and consistency in powder morphology. The particle size distribution range of micron powder and nanometer powder is large, which increases the tap density but makes it difficult to accurately focus on the electrical performance difference and particle size index of different batches of silver powder in silver paste application, increasing the difficulty of paste utilization.

[0004] Moreover, the existing silver powder preparation process is often manually dosed by hand, and when multiple raw materials need to be proportioned, they need to be done one by one, which is very troublesome and inefficient, and cannot meet the demand.

[0005] Therefore, in view of the above technical problems, the present application provides a high-dispersion and wide-distribution silver powder preparation method and device. SUMMARY

[0006] The present application is designed to solve the above problems, and provides a high-dispersion and wide-distribution silver powder preparation method and device, which can simultaneously complete the proportioning of silver ammonia solution A, dispersant solution B, surfactant solution C, and reducing liquid D through a dosing and mixing tank composed of an upper tank body and a movable lower seat body, greatly improving work efficiency.

[0007] To solve the above technical problems, the present application provides a high-dispersion and wide-distribution silver powder preparation device, characterized by comprising a guide rail, a flushing system, an oven, and a dosing and mixing tank composed of an upper tank body and a movable lower seat body. The movable lower seat body can be separated from the upper tank body and moved along the guide rail to a flushing station below the flushing system for flushing and to a heating station below the oven for drying. The guide rail is also connected to a movable cleaning assembly, which moves along the guide rail to the exact position below the upper tank body to flush the inside of the upper tank body.

[0008] The mobile cleaning assembly is composed of a recycling frame, an annular flushing pipe and a rotating disc, the annular flushing pipe is arranged on the rotating disc through a lifting mechanism, the rotating disc is rotatably connected to the bottom of the recycling frame through the driving of a rotating mechanism, and a plurality of flushing holes are arranged on the inner and outer rings of the annular flushing pipe.

[0009] Further, the upper tank body is composed of an outer shell, an upper cover plate, ingredient tanks, storage tanks and a stirring and mixing driving mechanism, the outer shell is supported on a platform through a protruding part integrally arranged on the outer wall, a cavity for mixing and depositing is formed between the outer shell and the mobile lower seat body, the upper cover plate is detachably mounted on the top of the outer shell, four storage tanks are arranged on the top of the upper cover plate, the storage tanks are connected to the upper cover plate through a weighing assembly, one ingredient tank is arranged below each storage tank, the four ingredient tanks are rotatably connected to the bottom of the upper cover plate and connected to the stirring and mixing driving mechanism, a first electric control unloading valve is arranged at the bottom of the storage tank, a second electric control unloading valve is arranged at the bottom of the ingredient tank, and the four ingredient tanks are also connected to a deionized water adding system.

[0010] Further, one upper connecting seat is arranged at the position corresponding to each storage tank at the bottom of the upper cover plate, the upper end of the ingredient tank is limited in the upper connecting seat under the action of a lower connecting seat and rotatably connected to the upper connecting seat through a first bearing arranged in the upper connecting seat, the lower connecting seat is detachably connected to the upper connecting seat, and the deionized water adding system is communicated with the four upper connecting seats, one of the upper connecting seats is also connected to a medicine adding and sampling system.

[0011] Further: the mobile lower seat body includes lower frame, pedestal, ring seat, plugging seat, screen structure, upper cylinder, support rod body, third lifting electric cylinder and fourth lifting electric cylinder, a circle of guide connection grooves is formed in the bottom of the lower frame, the guide sealing part matched with the guide connection groove is arranged on the pedestal, the guide sealing part extends into the guide connection groove and is connected with the guide connection groove through the spring, the sealing rubber ring is arranged between the inner wall of the guide connection groove and the outer wall of the guide sealing part, the ring seat is fixed to the outer side of the plugging seat through the connecting rod, the screen structure is arranged between the inner wall of the ring seat and the outer wall of the plugging seat, the ring seat is detachably mounted on the inner wall of the lower end of the lower frame, the lower end of the ring seat extends out of the lower frame, the bottom in the pedestal is concave, the depth of the concave surface matches the length of the ring seat extending out of the lower frame, the position of the bottom in the pedestal relative to the plugging seat is provided with a groove, the groove is provided with a flow hole, the bottom of the lower frame is provided with a pipeline quick connector communicated with the flow hole, each of the four corners of the bottom of the lower frame is vertically provided with an upper cylinder, the upper end of the support rod body extends into the upper cylinder and is movably connected with the upper cylinder, the third lifting electric cylinder is mounted on the top of the support rod body, the fourth lifting electric cylinder is mounted in the upper end of the upper cylinder, the shaft end of the fourth lifting electric cylinder is connected with the shaft end of the third lifting electric cylinder through the shaft coupling, when the third lifting electric cylinder and the fourth lifting electric cylinder are both started, the plugging seat extends into the groove and seals the flow hole.

[0012] The application also provides a preparation method of high-dispersion and wide-distribution silver powder, which specifically comprises the following steps:

[0013] S1: preparing silver ammonia solution by using deionized water through the first ingredient tank in the ingredient mixing tank, the mass concentration of silver nitrate is 8-26%, adding complexing agent, adjusting PH to 4-12, and obtaining solution A;

[0014] S2: preparing dispersant solution B by using deionized water through the second ingredient tank in the ingredient mixing tank, the mass concentration of the dispersant is 5-40%;

[0015] S3: preparing surfactant solution C by using deionized water through the third ingredient tank in the ingredient mixing tank, the mass concentration of the surfactant is 5-20%;

[0016] S4: preparing reducing liquid D by using deionized water through the fourth ingredient tank in the ingredient mixing tank, the mass concentration of the reducing agent is 4-25%;

[0017] S5: opening the second electric control unloading valve at the bottom of the fourth ingredient tank to send the reducing liquid D in the fourth ingredient tank into the mixing chamber composed of the outer shell and the lower frame, then opening the second electric control unloading valves at the bottoms of the second and third ingredient tanks to add B liquid and C liquid into D liquid respectively, stirring uniformly to form bottom liquid E, and adjusting PH to 4-8.

[0018] S6: open the second electric control discharge valve at the bottom of the first ingredient tank to add the A liquid evenly into the bottom liquid E, after fast stirring for 10 minutes, stand and settle;

[0019] S7: move the movable lower seat body directly below the washing system, and wash the silver powder after reaction and precipitation with deionized water and alcohol for 3 times respectively;

[0020] S8: the silver powder filtered through step S7 is moved to the direct lower part of the oven by the movable lower seat body, and dried at 60 DEG C for 8 hours to obtain the target silver powder.

[0021] Further: the silver ammonia complexing agent is ammonia water.

[0022] Further: the pH regulator is a combination of one or more of nitric acid, sodium hydroxide, ammonia water, ethylamine, ethanolamine and isopropanolamine.

[0023] Further: the dispersing agent is a non-ionic dispersing agent, wherein the ratio of high molecular weight and low molecular weight dispersing agent is 1:1, wherein the high molecular weight dispersing agent is one of polyvinylpyrrolidone and polyethylene glycol, and the low molecular weight dispersing agent is one of Tween and isomeric alcohol polyoxyethylene ether.

[0024] Further: the surfactant is obtained by compounding oleic acid and stearic acid.

[0025] Further: the reducing agent is prepared by mixing sodium borohydride, formaldehyde and ascorbic acid at a ratio of 1:1:1.

[0026] After adopting the above structure, the beneficial effects of the present application are as follows:

[0027] The present application can simultaneously complete the proportioning of silver ammonia solution A, dispersing agent solution B, surfactant solution C and reducing liquid D by the ingredient mixing tank composed of the upper tank body and the movable lower seat body, greatly improving the work efficiency.

[0028] The ingredient mixing tank structure adopted by the present application is to arrange four independent ingredient tanks in the mixing tank, which can be directly poured into the mixing tank for mixing after the ingredient is completed, thereby increasing the practical performance.

[0029] The present application adopts a movable lower seat body, which can directly transport the silver powder precipitated and settled, without the need for collection and transportation, thereby greatly improving the work efficiency.

[0030] The particle size distribution of the spherical silver powder prepared by the preparation method adopted by the present application presents two regular sizes, which are composed of micron and sub-micron. The tap density is high, the specific surface is moderate, and the monodispersity is good. The spherical silver powder has good application prospect in the fields of solar cell silver paste and traditional conductive silver paste. BRIEF DESCRIPTION OF DRAWINGS

[0031] The present application will be further described in detail below in combination with the drawings and specific embodiments.

[0032] Figure 1 It is a structural schematic diagram of the preparation device.

[0033] Figure 2 It is a structural diagram of the ingredient mixing tank.

[0034] Figure 3 It is Figure 2 It is an enlarged view of the middle A.

[0035] Figure 4 It is an internal structural diagram of the upper tank body.

[0036] Figure 5 It is a structural diagram of the mobile lower seat body.

[0037] Figure 6 It is Figure 5 It is an enlarged view of the middle B.

[0038] Figure 7 It is a structural diagram of the mobile cleaning assembly.

[0039] Figure 8 It is Figure 7 It is an enlarged view of the middle C.

[0040] Figure 9 It is an internal structural diagram of the pipeline quick connector.

[0041] Figure 10 It is a schematic diagram of the silver powder of three embodiments processed by the preparation method of the present application.

[0042] In the figure: 1 is the upper tank body, 2 is the upper support plate, 3 is the deionized water flushing storage tank, 4 is the alcohol storage tank, 5 is the first flushing chamber, 6 is the second flushing chamber, 7 is the oven, 8 is the movable cleaning assembly, 9 is the movable lower seat body, 10 is the upper cover plate, 11 is the outer shell body, 12 is the protruding part, 13 is the platform, 14 is the PH adjusting agent storage tank, 15 is the PH detector, 17 is the stand column, 18 is the pumping pump, 19 is the peristaltic pump, 20 is the second three-way control valve, 21 is the first three-way control valve, 22 is the first liquid pumping pipe, 23 is the second liquid pumping pipe, 24 is the pumping pipe, 25 is the weighing assembly, 26 is the storage tank, 27 is the deionized water conveying main pipe, 28 is the conveying auxiliary pipe, 29 is the valve assembly, 30 is the upper connecting seat, 31 is the lower connecting seat, 32 is the rotating shaft, 33 is the mixing drive gear, 34 is the transmission gear, 35 is the ingredient tank, 36 is the second electric control unloading valve, 37 is the stirring paddle, 38 is the lower frame body, 39 is the base, 40 is the blocking seat, 41 is the pipeline quick connector, 41-1 is the first valve body, 41-1-1 is the drainage groove, 41-2 is the second valve body, 41-3 is the annular valve core, 41-4 is the valve core spring, 42 is the upper cylinder, 43 is the annular flushing pipeline, 44 is the second track walking wheel, 45 is the guide sealing part, 46 is the annular seat, 47 is the screen structure, 48 is the spring, 49 is the recovery frame body, 50 is the electric telescopic rod, 51 is the first track walking wheel, 52 is the mechanical sealing structure, 53 is the flange assembly, 54 is the pinion, 55 is the drive motor, 56 is the second lifting electric cylinder, 57 is the flushing pump, 58 is the clamp, 59 is the lower cylinder, 60 is the first telescopic cylinder, 61 is the second telescopic cylinder, 62 is the hose reel, 63 is the conveying hose, 64 is the first lifting electric cylinder, 65 is the large gear ring, 67 is the guide rail, 68 is the support rod body, 69 is the turntable. DETAILED DESCRIPTION

[0043] As Figure 1The device for preparing high-dispersion and wide-distribution silver powder is shown in the figure, which comprises a guide rail 67, a flushing system, an oven 7, and a mixing tank composed of an upper tank body 1 and a movable lower seat body 9. The movable lower seat body 9 can be separated from the upper tank body 1 and sequentially moved along the guide rail 67 to a flushing station below the flushing system for flushing and to a heating station below the oven for drying. A movable cleaning assembly 8 is also connected to the guide rail 67 and moved to the position directly below the upper tank body 1 to flush the inside of the upper tank body 1. During preparation, liquid preparation, mixing, and precipitation are sequentially performed in the mixing tank to obtain silver powder with mixed liquid. Then, the movable lower seat body 9 is separated from the upper tank body 1, and the movable lower seat body 9 is moved to the position below the flushing system to sequentially perform deionized water washing and alcohol flushing to remove the mixed liquid adhered to the surface of the silver powder. The movable lower seat body 9 is continuously moved to the heating station to heat the silver powder, thereby obtaining dry silver powder. After the movable lower seat body 9 is separated from the upper tank body 1, the movable cleaning assembly 8 is moved to the position below the upper tank body 1 to flush the inside of the upper tank body 1 to remove the mixed liquid and silver powder remaining in the upper tank body 1. The mixed liquid and silver powder after cleaning are collected by the movable cleaning assembly 8 for re-collection, thereby reducing unnecessary waste of resources.

[0044] As shown in the figure, Figure 1 The flushing system comprises an upper support plate 2, a deionized water flushing tank 3 arranged on the top of the upper support plate, and an alcohol tank 4. A first flushing chamber 5 is arranged on the bottom of the upper support plate 2 directly below the deionized water flushing tank 3. A second flushing chamber 6 is arranged on the bottom of the upper support plate 2 directly below the alcohol tank 4. The left and right ends of the first flushing chamber 5 and the second flushing chamber 6 are open. The movable lower seat body 9 sequentially passes through the first flushing chamber 5 and the second flushing chamber 6 along the guide rail.

[0045] As shown in the figure, Figure 1 The oven is in a suspended state, and an oven inlet is arranged on the bottom of the oven. The base of the movable lower seat body 9 enters the inside of the oven for silver powder drying under the action of the third lifting cylinder along the oven inlet.

[0046] As shown in the figure, Figure 7The mobile cleaning assembly 8 shown is composed of a recycling frame 49, an annular flushing pipe 43 and a rotating disc 69, the annular flushing pipe 43 is arranged on the rotating disc 69 through a lifting mechanism, the rotating disc 69 is rotatably connected to the bottom of the recycling frame 49 through the driving of a rotating mechanism, a plurality of flushing holes are arranged on the inner and outer rings of the annular flushing pipe 43, the bottom of the recycling frame 49 is connected with a first track wheel 51 through an electric telescopic rod 50, a recycling hole is arranged in the bottom of the recycling frame 49, and the recycling hole is connected with a recycling pipe through a flange assembly 53 arranged at the bottom of the recycling frame 49.

[0047] As shown in Figure 7 and Figure 8 The rotating mechanism includes an annular limiting seat arranged in the bottom of the recycling frame and matched with the rotating disc, a driving motor 55, a pinion 54 and a large gear ring 65, the lower end of the rotating disc is rotatably connected in the annular limiting seat, the driving motor is installed at the bottom of the recycling frame, the pinion 54 is sleeved on the output shaft of the driving motor extending into the recycling frame, the large gear ring is sleeved on the outer wall of the upper end of the rotating disc, and the pinion is meshed with the large gear ring. The rotating disc is rotated by controlling the driving motor and utilizing the cooperation of the pinion and the large gear ring, and the rotating mechanism has the advantages of simple structure, convenient use and high practicability.

[0048] As shown in Figure 8The lifting mechanism includes a first lifting cylinder 64, a second lifting cylinder 56, a lower cylinder 59, a first telescopic cylinder 60 and a second telescopic cylinder 61. The top of each end of the rotating disc is vertically fixed with a lower cylinder 59. The lower end of the first telescopic cylinder 60 extends into the lower cylinder 59 and is slidably connected with the lower cylinder 59. The first lifting cylinder 64 is installed on the outer wall of the lower cylinder 59 and the shaft end thereof is connected with the upper end of the first telescopic cylinder 60. The lower end of the second telescopic cylinder 61 extends into the first telescopic cylinder 60 and is slidably connected with the first telescopic cylinder 60. The second lifting cylinder 56 is installed on the outer wall of the first telescopic cylinder 60 and the shaft end thereof is connected with the upper end of the second telescopic cylinder 61. The annular flushing pipeline 43 is fixed on the upper end of the second telescopic cylinder 61 through a clamp 58. During operation, the annular flushing pipeline 43 is lifted by controlling the first lifting cylinder 64 and the second lifting cylinder 56.

[0049] As shown in Figure 7 and Figure 8 The rotating disc is provided with a flushing pump 57 at the center of the top thereof. The flushing pump 57 is connected with a mechanical seal structure 52 arranged at the bottom of the recycling frame 49 through a first pipeline. The first pipeline passes through the rotating disc and extends out of the recycling frame to be rotatably connected with the mechanical seal structure 52. The mechanical seal structure 52 is connected in communication with a water storage tank through a second pipeline. The rotating disc is provided with a hose reel 62 on each side of the flushing pump 57. The hose reel 62 is rotatably connected with the rotating disc and the inner wall thereof is provided with a flow guide cavity. The flushing pump 57 is connected in communication with the flow guide cavity in the hose reel 62 through a third pipeline. One end of the third pipeline is rotatably connected with the top of the hose reel 62. The surface of the hose reel 62 is wound with a conveying hose 63. One end of the conveying hose 63 is fixed on the hose reel 62 and connected in communication with the flow guide cavity. The other end of the conveying hose 63 extends into the lifting mechanism and is connected in communication with the annular flushing pipeline 43. When the annular flushing pipeline is lifted, the conveying hose will automatically rotate with the hose reel 62. When the annular flushing pipeline is collected, the hose is rewound by reversely rotating the hose reel 62.

[0050] As shown in Figure 2 and Figure 4The upper tank body 1 is composed of an outer shell 11, an upper cover plate 10, ingredient tanks 35, storage tanks 26 and a stirring and mixing driving mechanism. The outer shell 11 is supported on a platform 13 by a protrusion 12 integrally arranged on the outer wall of the outer shell 11. The platform 13 is suspended by a plurality of vertical columns 17 arranged on the bottom. A cavity for mixing and depositing is formed between the outer shell 11 and the movable lower seat body 9. The upper cover plate 10 is detachably mounted on the top of the outer shell 11. Four storage tanks 26 are arranged on the top of the upper cover plate 10. The storage tanks are connected to the upper cover plate 10 by a weighing assembly. One ingredient tank 35 is arranged below each of the four storage tanks 26. The four ingredient tanks 35 are rotatably connected to the bottom of the upper cover plate 10 and are connected to the stirring and mixing driving mechanism. First electrically controlled discharge valves are arranged on the bottom of the storage tanks 26. Second electrically controlled discharge valves 36 are arranged on the bottom of the ingredient tanks 35. The four ingredient tanks are also connected to a deionized water adding system. During operation, silver amine solution A, dispersant solution B, surface active agent solution C and reducing solution D are respectively prepared in the four ingredient tanks by the four storage tanks 26 and the deionized water adding system. Then, the dispersant solution B, the surface active agent solution C and the reducing solution D are poured into the ingredient mixing tank composed of the upper tank body 1 and the movable lower seat body 9, and are stirred uniformly to form a bottom liquid E. Then, the silver amine solution A is added into the ingredient mixing tank, and silver powder is precipitated by rapid stirring.

[0051] As shown in the upper cover plate, Figure 4 An upper connecting seat 30 is arranged on the bottom of the upper cover plate opposite to each of the four storage tanks. The upper end of the ingredient tank 35 is limited in the upper connecting seat 30 under the action of a lower connecting seat 31 and is rotatably connected to the upper connecting seat 30 by a first bearing arranged in the upper connecting seat 30. The lower connecting seat 31 is detachably connected to the upper connecting seat 30. The deionized water adding system is communicated with the four upper connecting seats 30. One of the upper connecting seats 30 is also connected to a medicament adding and sampling system. The upper connecting seat connected to the medicament adding and sampling system is also connected to a complexing agent adding pipeline. The medicament adding and sampling system can detect and adjust the PH value of the silver amine solution A and the PH value in the ingredient mixing tank, and the adjustment is made according to the detection result.

[0052] As shown in the upper cover plate, Figure 4The stirring mixing driving mechanism shown comprises a rotary motor, a rotating shaft 32, a mixing driving gear 33, a transmission gear 34 and a stirring paddle 37. The rotary motor is installed at the center of the top of the upper cover plate 10, the output shaft of the rotary motor is connected with the vertically arranged rotating shaft 32 through the upper cover plate 10, the rotating shaft 32 is rotated by the driving of the rotary motor, the mixing driving gear 33 is sleeved on the rotating shaft 32 and rotates together, one transmission gear 34 is fixedly sleeved on the outer wall of each of the four ingredient tanks 35, the mixing driving gear 33 is engaged with the four transmission gears 34, the four ingredient tanks are rotated respectively by the gear transmission, the stirring paddle 37 is sleeved on the lower end of the rotating shaft and rotates together, and the stirring paddle is located directly below the ingredient tank. The rotary motor can not only rotate the four ingredient tanks respectively to complete the ingredient work, but also can complete the stirring and mixing work of the whole by the stirring paddle at the lower end of the rotating shaft after the respective ingredient work is completed, thereby increasing the practicability.

[0053] As shown in Figure 4 The deionized water adding system shown comprises two deionized water conveying main pipes 27, a conveying auxiliary pipe 28 and a valve assembly 29 with a flow meter. One end of the deionized water conveying main pipe 27 is communicated with a deionized water storage tank, the valve assembly 29 is arranged on the conveying auxiliary pipe 28, one end of the conveying auxiliary pipe 28 is communicated with the deionized water conveying main pipe 27, the other end of the conveying auxiliary pipe 28 is communicated with the ingredient tank 35 through an upper connecting seat 30, every two ingredient tanks 35 are connected with one deionized water conveying main pipe 27, and the conveying amount of the deionized water is accurately controlled by the display of the flow meter during work.

[0054] As shown in Figure 4 The storage tank 26 is connected with the upper cover plate through a weighing assembly 25, the weighing assembly 25 comprises a placing seat, a weighing sensor and an annular support plate, the annular support plate is arranged in the placing seat through the weighing sensor, the lower end of the storage tank is inserted into the placing seat and supported on the annular support plate, and the bottom of the placing seat and the upper cover plate are both provided with a through slot relative to the position of the first electric control unloading valve. The unloading amount of the raw material in the storage tank is accurately controlled by the display of the weighing sensor during work.

[0055] As shown in Figure 2 and Figure 3The shown medicine adding and sampling system comprises a PH detector 15, a PH adjusting agent storage tank 14, a sampling pump 18, a peristaltic pump 19, a first three-way control valve 21 and a second three-way control valve 20, the first three-way control valve 20 and the second three-way control valve 21 are respectively installed on the inner and outer walls of the upper tank body and are communicated with each other, the first three-way control valve is also respectively communicated with a first sampling pipe 22 and a second sampling pipe 23, the first sampling pipe 22 penetrates through the upper connecting seat and extends into the bottom of the ingredient tank, the second sampling pipe extends into the lower end of the ingredient mixing tank, the peristaltic pump is installed on the outer wall of the upper tank body and its inlet and outlet are respectively communicated with the second three-way control valve and the PH detector, the sampling pump 18 is arranged on the top of the PH adjusting agent storage tank and is communicated with the same, and the sampling pump is also communicated with the second three-way control valve 20 through a sampling pipe 24. When working, the peristaltic pump is started to sample first, and the sampling pump is used to add the corresponding amount of PH adjusting agent according to the display result of the PH detector; the present application can automatically complete the PH detection and adjusting work by adopting the above design, and has the effect of increasing the practical performance.

[0056] As Figure 5 and Figure 6The movable lower seat 9 shown includes a lower frame 38, a base 39, an annular seat 46, a blocking seat 40, a screen structure 47, an upper cylinder 42, a support rod 68, a third lifting electric cylinder and a fourth lifting electric cylinder. A guide connecting groove is formed in the bottom of the lower frame 38. A guide sealing part 45 matched with the guide connecting groove is arranged on the base. The guide sealing part 45 extends into the guide connecting groove and is connected with the guide connecting groove through a spring 48. A sealing rubber ring is arranged between the inner wall of the guide connecting groove and the outer wall of the guide sealing part. The annular seat 46 is fixed on the outside of the blocking seat 40 through a connecting rod. The screen structure 47 is arranged between the inner wall of the annular seat 46 and the outer wall of the blocking seat 40. The annular seat is detachably mounted on the lower end inner wall of the lower frame 38. The lower end of the annular seat extends out of the lower frame. The bottom in the base is concave. The depth of the concave surface matches the length of the annular seat extending out of the lower frame. A groove is formed in the position of the bottom in the base relative to the blocking seat 40. A flow hole is formed in the groove. A pipeline quick connector 41 is arranged in the bottom of the lower frame and communicates with the flow hole. An upper cylinder 42 is vertically arranged in each corner of the bottom of the lower frame 38. The upper end of the support rod 68 extends into the upper cylinder 42 and is movably connected with the upper cylinder 42. The third lifting electric cylinder is mounted on the top of the support rod 68. The fourth lifting electric cylinder is mounted in the upper end of the upper cylinder 42. The shaft end of the fourth lifting electric cylinder is connected with the shaft end of the third lifting electric cylinder through a shaft coupling. When the third lifting electric cylinder and the fourth lifting electric cylinder are both started, the blocking seat 40 extends into the groove and seals the flow hole. During work, the third lifting electric cylinder and the fourth lifting electric cylinder are first started to seal the flow hole with the blocking seat 40. After the stirring and precipitation are completed, the pipeline quick connector is connected with the mixed liquid recovery pipeline, then the fourth lifting electric cylinder is closed. The lower frame and the base are displaced under the action of the spring, so as to open the flow hole. The mixed liquid flows out along the flow hole. The silver powder precipitated and separated is left in the base. After the movable lower seat and the upper tank are separated, the third lifting electric cylinder is closed. The movable lower seat is moved through the second track running wheel 44 arranged at the bottom of the support rod 68.

[0057] As Figure 9The shown pipeline quick connector 41 comprises a first valve body 41-1, a second valve body 41-2, an annular valve core 41-3 and a valve core spring 41-4, the upper end of the first valve body is communicated with a leakage hole, the lower end of the first valve body extends into the second valve body and is in sealing state, the first valve body is fixedly connected with the second valve body, the annular valve core is connected between the outer wall of the first valve body and the inner wall of the second valve body in a piston type and is connected with the second valve body through the valve core spring, a leakage groove 41-1-1 is formed in the side wall of the first valve body in the second valve body, the leakage groove 41-1-1 is sealed through the annular valve core, and an internal thread is arranged on the inner wall of the second valve body away from the first valve body. When being communicated, the outer connecting pipeline is inserted into the second valve body to press the annular valve core through the cooperation of the internal and external threads, so that the leakage groove is opened, and the mixed solution is discharged through the leakage groove. The structure of the application plays a role of quick disassembly and assembly. Example one:

[0058] The application provides a preparation method of high-dispersion and wide-distribution silver powder.

[0059] S1: a silver-ammonia solution is prepared by using deionized water through a first ingredient tank in an ingredient mixing tank, the mass concentration of silver nitrate is 8%, a complexing agent is added, and the PH value is adjusted to 4 to obtain a solution A;

[0060] S2: a dispersant solution B is prepared by using deionized water through a second ingredient tank in the ingredient mixing tank, and the mass concentration of the dispersant is 5%;

[0061] S3: a surfactant solution C is prepared by using deionized water through a third ingredient tank in the ingredient mixing tank, and the mass concentration of the surfactant is 5%;

[0062] S4: a reducing solution D is prepared by using deionized water through a fourth ingredient tank in the ingredient mixing tank, and the mass concentration of the reducing agent is 4%;

[0063] S5: the second electric control unloading valve at the bottom of the fourth ingredient tank is opened first to send the reducing solution D in the fourth ingredient tank into a mixing chamber composed of an outer shell and a lower frame body, then the second electric control unloading valves at the bottoms of the second and third ingredient tanks are opened to add the B solution and the C solution into the D solution respectively, the B solution and the C solution are stirred to form a bottom solution E, and the PH value is adjusted to 4;

[0064] S6: the second electric control unloading valve at the bottom of the first ingredient tank is opened to add the A solution into the bottom solution E, and after being stirred rapidly for 10 minutes, the mixture is placed and settled;

[0065] S7: the movable lower seat body is moved to be directly below a flushing system, and the silver powder after reaction and precipitation is washed with deionized water and alcohol for three times respectively;

[0066] S8: The silver powder filtered in step S7 is moved to the direct lower side of the oven using a movable lower seat body, and is dried at a temperature of 60 DEG C for 8 hours to obtain the target silver powder.

[0067] The complexing agent in the method is ammonia water, the pH regulator is a combination of one or more of nitric acid, sodium hydroxide, ammonia water, ethylamine, ethanolamine, and isopropanolamine; the dispersing agent is a non-ionic dispersing agent, wherein the ratio of high molecular weight and low molecular weight dispersing agents is 1:1, wherein the high molecular weight dispersing agent is one of polyvinylpyrrolidone and polyethylene glycol, and the low molecular weight dispersing agent is one of Tween and isomeric alcohol polyoxyethylene ether. The surfactant is obtained by compounding oleic acid and stearic acid. The reducing agent is prepared by mixing sodium borohydride, formaldehyde, and ascorbic acid at a ratio of 1:1:1.

[0068] The silver powder prepared by the method has a micron particle size that is more than 4-5 times the sub-micron particle size, a high tap density, a moderate specific surface area, and good monodispersity, and has good application prospects in the fields of solar cell silver paste and traditional conductive silver paste. Figure 10 Example 2

[0069] The application provides a high-dispersion and wide-distribution silver powder preparation method, which specifically comprises the following steps.

[0070] S1: using deionized water, preparing a silver-ammonia solution through a first ingredient tank in a batching mixing tank, wherein the mass concentration of silver nitrate is 15%, adding a complexing agent, and adjusting the pH to 7 to obtain solution A;

[0071] S2: using deionized water, preparing a dispersing agent solution B through a second ingredient tank in the batching mixing tank, wherein the mass concentration of the dispersing agent is 22%;

[0072] S3: using deionized water, preparing a surfactant solution C through a third ingredient tank in the batching mixing tank, wherein the mass concentration of the surfactant is 12%;

[0073] S4: using deionized water, preparing a reducing agent solution D through a fourth ingredient tank in the batching mixing tank, wherein the mass concentration of the reducing agent is 15%;

[0074] S5: first, opening the second electric control discharge valve at the bottom of the fourth ingredient tank to send the reducing agent solution D in the fourth ingredient tank into a mixing chamber composed of an outer shell and a lower frame, then opening the second electric control discharge valves at the bottoms of the second and third ingredient tanks to add the B solution and the C solution into the D solution respectively, stirring to form a bottom solution E, and adjusting the pH to 6;

[0075] S6: opening the second electric control discharge valve at the bottom of the first ingredient tank to add the A solution into the bottom solution E uniformly, stirring rapidly for 10 minutes, and then standing and settling.​

[0076] S7: moving the movable lower seat body to be directly below the washing system, and washing the silver powder after reaction and precipitation with deionized water and alcohol respectively for three times;

[0077] S8: moving the silver powder after filtering in step S7 to be directly below the oven by using the movable lower seat body, and drying the silver powder at 60 DEG C for 8 hours to obtain the target silver powder.

[0078] The silver powder prepared by the method is shown in the figure, wherein the number of microparticles is approximately equal to that of submicron particles, the tap density of the silver powder after detection is high, the specific surface is moderate, and the monodispersity is good. Figure 10 The silver powder has good application prospect in the fields of solar cell silver paste and traditional conductive silver paste. Example three:

[0079] The application further provides a preparation method of high-dispersion and wide-distribution silver powder, which specifically comprises the following steps:

[0080] S1: preparing silver ammonia solution by using deionized water and a first ingredient tank in an ingredient mixing tank, the mass concentration of silver nitrate is 26%, a complexing agent is added, and the PH is adjusted to 12 to obtain solution A;

[0081] S2: preparing dispersant solution B by using deionized water and a second ingredient tank in the ingredient mixing tank, wherein the mass concentration of the dispersant is 40%;

[0082] S3: preparing surfactant solution C by using deionized water and a third ingredient tank in the ingredient mixing tank, wherein the mass concentration of the surfactant is 20%;

[0083] S4: preparing reducing liquid D by using deionized water and a fourth ingredient tank in the ingredient mixing tank, wherein the mass concentration of the reducing agent is 25%;

[0084] S5: opening the second electric control unloading valve at the bottom of the fourth ingredient tank to send the reducing liquid D in the fourth ingredient tank into the mixing chamber composed of an outer shell body and a lower frame body, then opening the second electric control unloading valves at the bottoms of the second ingredient tank and the third ingredient tank to add the B liquid and the C liquid into the D liquid respectively, stirring to form bottom liquid E, and adjusting the PH to 8;

[0085] S6: opening the second electric control unloading valve at the bottom of the first ingredient tank to add the A liquid into the bottom liquid E, stirring rapidly for 10 min, and then standing and settling;

[0086] S7: moving the movable lower seat body to be directly below the washing system, and washing the silver powder after reaction and precipitation with deionized water and alcohol respectively for three times;

[0087] S8: the silver powder filtered in step S7 is moved to the direct lower side of the oven by using a movable lower seat body, and is dried at 60 DEG C for 8 hours to obtain the target silver powder.

[0088] The silver powder prepared by the method has a sub-micron particle size, is more than micron particle size, and has a ratio of 3 to 5, a high tap density after detection, a moderate specific surface, and good monodispersity, and has a good application prospect in the fields of solar cell silver paste and traditional conductive silver paste. Figure 10

[0089] The above is only the preferred embodiment of the present application, and the protection scope of the present application is not limited to the above-mentioned embodiments, and any technical scheme falling within the idea of the present application belongs to the protection scope of the present application. It should be noted that, for ordinary skilled in the art, some improvements and refinements without departing from the principle of the present application should be considered as the protection scope of the present application.​

Claims

1. A device for preparing highly dispersed, wide-distribution silver powder, characterized in that: The utility model discloses a kind of mixing tanks, including guide rail, flushing system, oven and by upper tank body and movable lower seat body, the movable lower seat body can be separated from the upper tank body and sequentially moved to the flushing station below flushing system for flushing and moved to the heating station below oven for drying, mobile cleaning assembly is also connected on the guide rail, and mobile cleaning assembly moves to the inside of upper tank body for flushing by being directly below it along guide rail; The mobile cleaning assembly is composed of a recycling frame, an annular flushing pipe and a rotating disc. The annular flushing pipe is arranged on the rotating disc through a lifting mechanism. The rotating disc is rotatably connected to the bottom of the recycling frame through the driving of a rotating mechanism. A plurality of flushing holes are arranged on the inner and outer rings of the annular flushing pipe. The upper tank body is composed of an outer shell, an upper cover plate, ingredient tanks, storage tanks and a stirring and mixing driving mechanism. The outer shell is supported on a platform through the protrusions arranged on the outer wall. The outer shell and the movable lower seat body form a cavity for mixing and depositing. The upper cover plate is detachably mounted on the top of the outer shell. Four storage tanks are arranged on the top of the upper cover plate. The storage tanks are connected to the upper cover plate through a weighing assembly. One ingredient tank is arranged below each storage tank. The four ingredient tanks are rotatably connected to the bottom of the upper cover plate and connected to the stirring and mixing driving mechanism. A first electric control unloading valve is arranged on the bottom of each storage tank. A second electric control unloading valve is arranged on the bottom of each ingredient tank. The four ingredient tanks are also connected to a deionized water adding system. An upper connecting seat is arranged on the bottom of the upper cover plate and opposite to each storage tank. The upper end of each ingredient tank is limited in the upper connecting seat under the action of a lower connecting seat and rotatably connected to the upper connecting seat through a first bearing arranged in the upper connecting seat. The lower connecting seat is detachably connected to the upper connecting seat. One of the upper connecting seats is also connected to a medicament adding and sampling system. The upper connecting seat connected to the medicament adding and sampling system is also connected to a complexing agent adding pipeline. The medicament adding and sampling system includes a PH detector, a PH adjusting tank, a sampling pump, a peristaltic pump, a first three-way control valve and a second three-way control valve. During operation, silver ammonia solution A, dispersant solution B, surface active agent solution C and reducing solution D are respectively prepared in the four ingredient tanks through the four storage tanks and the deionized water adding system. Then, the dispersant solution B, the surface active agent solution C and the reducing solution D are poured into the mixing tank composed of the upper tank body and the movable lower seat body, and stirred uniformly to form a bottom liquid E. Finally, the silver ammonia solution A is added into the mixing tank, and the silver powder is precipitated after rapid stirring.

2. The device for preparing high-dispersion, wide-distribution silver powder according to claim 1, characterized in that: The mobile lower seat body includes a lower frame body, a base, an annular seat, a blocking seat, a screen structure, an upper cylinder, a support rod body, a third lifting electric cylinder and a fourth lifting electric cylinder, a guide connection groove is formed in the bottom of the lower frame body, a guide sealing part matched with the guide connection groove is arranged on the base, the guide sealing part extends into the guide connection groove and is connected with the guide connection groove through a spring, a sealing rubber ring is arranged between the inner wall of the guide connection groove and the outer wall of the guide sealing part, the annular seat is fixed to the outer side of the blocking seat through a connecting rod, the screen structure is arranged between the inner wall of the annular seat and the outer wall of the blocking seat, the annular seat is detachably mounted on the inner wall of the lower end of the lower frame body, the lower end of the annular seat extends out of the lower frame body, the bottom of the base is concave, the depth of the concave surface is matched with the length of the annular seat extending out of the lower frame body, a groove is formed in the position of the bottom of the base relative to the blocking seat, a flow hole is formed in the groove, a pipeline quick connector is arranged in the bottom of the lower frame body and communicated with the flow hole, an upper cylinder is vertically arranged at each corner of the bottom of the lower frame body, the upper end of the support rod body extends into the upper cylinder and is movably connected with the upper cylinder, the third lifting electric cylinder is mounted on the top of the support rod body, the fourth lifting electric cylinder is mounted in the upper end of the upper cylinder, the output shaft end of the fourth lifting electric cylinder is connected with the output shaft end of the third lifting electric cylinder through a shaft coupling, when the third lifting electric cylinder and the fourth lifting electric cylinder are both started, the blocking seat extends into the groove and seals the flow hole.

3. A method for producing a high dispersion, wide distribution silver powder using the apparatus of claim 1, characterized by: Specifically comprising the following steps: S1: using deionized water to prepare silver amine solution through the first ingredient tank in the ingredient mixing tank, the mass concentration of silver nitrate is 8-26%, a complexing agent is added, the PH is adjusted to 4-12, and solution A is obtained; S2: using deionized water to prepare dispersant solution B through the second ingredient tank in the ingredient mixing tank, wherein the mass concentration of the dispersant is 5-40%; S3: using deionized water to prepare surfactant solution C through the third ingredient tank in the ingredient mixing tank, wherein the mass concentration of the surfactant is 5-20%; S4: using deionized water to prepare reducing liquid D through the fourth ingredient tank in the ingredient mixing tank, wherein the mass concentration of the reducing agent is 4-25%; S5: first, open the second electric control unloading valve at the bottom of the fourth ingredient tank to send the reducing liquid D in it into the mixing chamber composed of the outer shell and the lower frame, then open the second electric control unloading valves at the bottoms of the second and third ingredient tanks to add B liquid and C liquid into D liquid respectively, stir uniformly to form bottom liquid E, and adjust the PH to 4-8; S6: open the second electric control unloading valve at the bottom of the first ingredient tank to add A liquid into the bottom liquid E, stir quickly for 10 minutes, and then stand for settlement; S7: move the mobile lower seat body to the position directly below the washing system, and wash the silver powder after reaction and precipitation with deionized water and alcohol respectively for three times; S8: move the silver powder filtered through step S7 to the position directly below the oven using the mobile lower seat body, dry at 60℃ for 8 hours, and the target silver powder can be obtained. The dispersing agent is a non-ionic dispersing agent, wherein the ratio of high molecular weight and low molecular weight dispersing agent is 1:1, wherein the high molecular weight dispersing agent is one of polyvinylpyrrolidone and polyethylene glycol, and the low molecular weight dispersing agent is one of Tween and isomeric alcohol polyoxyethylene ether.

4. The method of claim 3, wherein the silver powder has a distribution width of 0.3 or less. The complexing agent is ammonia.

5. The method of claim 3, wherein the silver powder has a distribution width of 0.3 or less. The pH regulator is a combination of one or more of nitric acid, sodium hydroxide, ammonia, ethylamine, ethanolamine, and isopropyl alcoholamine.

6. The method of claim 3, wherein the silver powder has a high dispersion and a wide distribution. The surfactant is obtained by compounding oleic acid and stearic acid.

7. The method of claim 3, wherein the silver powder has a high dispersion and a wide distribution. The reducing agent is obtained by mixing sodium borohydride, formaldehyde, and ascorbic acid at a ratio of 1:1:1.

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