A method and equipment for continuous mass production of spherical silver powder

Abstract

The present invention relates to the technical field of silver powder preparation, and in particular to a method and apparatus for the continuous mass production of spherical silver powder, comprising a cylindrical crucible, a tungsten needle disposed at the right end of the cylindrical crucible, and a graphite turntable disposed to the right of the tungsten needle. In the present invention, molten silver is sprayed into a nano-spray stream using the cylindrical crucible and the tungsten needle, which is then received by a rotating graphite disk coated with a magnesium oxide layer. Under the high-speed rotation of the graphite disk, the silver stream is intercepted and separated before solidification. When the silver stream contacts the magnesium oxide layer, the liquid / solid non-wetting effect, in which the magnesium oxide layer and silver do not wet each other, causes the intercepted silver stream to form spherical silver powder during the tumbling process. The resulting silver powder has good sphericity, a smooth surface, and excellent conductivity. Compared with conventional spray pyrolysis methods, this method overcomes the problems of poor sphericity and wide particle size distribution.

Description

Technical Field

[0001] The present invention relates to the technical field of silver powder preparation, in particular to a method and equipment for continuous mass production of spherical silver powder. Background Art

[0002] Silver powder is typically prepared using a liquid-phase reduction method. However, this traditional method is difficult to improve, produces a significant amount of wastewater during the preparation process, and the resulting silver powder is prone to soft agglomeration. Organic matter-coated silver powder is difficult to clean. Improvements to liquid-phase reduction apparatus have primarily focused on the microtitration step. Physical methods for preparing silver nanoparticles offer a simple process and produce high-purity, high-performance silver nanoparticles. However, these methods require stringent instrumentation and are expensive.

[0003] The physical atomization method involves pulverizing molten metal liquid in an atomizer with a high-pressure airflow. The pulverized metal liquid splatters into countless tiny spherical particles, which are then collected by a cooling medium to form a powder. Conventional atomization methods produce relatively coarse metal powders, typically 0.01-1mm in diameter. The typical particle size of silver powder used in front-side silver pastes is 1-2μm, so controlling the powder's particle size distribution and sphericity is crucial.

[0004] The traditional spray pyrolysis method has a wide particle size distribution and uncontrolled sphericity. Therefore, to address the above problems, a method and equipment for large-scale continuous production of spherical silver powder are proposed. Summary of the Invention

[0005] The object of the present invention is to provide a method and apparatus for the large-scale continuous production of spherical silver powder, so as to solve the problems raised in the above-mentioned background technology.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A device for continuously producing a large amount of spherical silver powder, comprising a cylindrical crucible, a tungsten needle arranged at the right end of the cylindrical crucible, and a graphite turntable arranged at the right side of the tungsten needle;

[0008] The tungsten needle is provided with a central hole along the axis of the tungsten needle, and the graphite turntable is perpendicular to the right side of the central hole of the tungsten needle to receive the wire ejected from the central hole;

[0009] A silver raw material is loaded into a cylindrical crucible, and the silver raw material is ejected through the central hole of a tungsten needle to spin into fibers at the outlet end of the tungsten needle;

[0010] The surface of the left panel of the graphite turntable is provided with a magnesium oxide coating, and the cylindrical crucible is connected to the tungsten needle;

[0011] The invention also includes a high-voltage DC power supply, wherein the positive electrode of the high-voltage DC power supply is connected to the tungsten needle, the outer shell of the graphite turntable is grounded, and the tungsten needle, the silver raw material and the outer shell of the graphite turntable form a high-voltage electric field;

[0012] A graphite piston is slidably arranged inside the cylindrical crucible, and the negative pole of the high-voltage DC power supply is connected to the graphite piston and electrically contacts the silver raw material.

[0013] Preferably, it also includes a frame, a mounting frame for mounting a cylindrical crucible is fixedly provided in the middle position of the bottom plate of the frame, a driving table extending to the left end of the frame is fixedly provided at the left end of the mounting frame, a second spiral bevel gear box and a slide are fixedly provided on the driving table from left to right, a screw rod is rotatably provided inside the slide, and a slider sliding in the slide is provided on the screw rod, a push plate is fixedly provided on the top of the slider, and a push rod connected to the graphite piston is fixedly provided on the push plate.

[0014] Preferably, a rotating mounting cylinder is fixedly provided on the right side frame of the frame and passes through the side frame horizontally, and a rotating shaft is provided at the middle of the right end of the graphite turntable, which passes through the rotating mounting cylinder and is rotatably connected to the inside of the rotating mounting cylinder through a bearing.

[0015] Preferably, a mounting table is fixedly provided on the right side frame of the frame below the rotating mounting cylinder, and a first spiral bevel gearbox and a drive motor are arranged on the mounting table from left to right. The output shaft at the left end of the first spiral bevel gearbox is connected to the shaft of the graphite turntable through a coupling, and the motor shaft of the drive motor is connected to the drive shaft at the right end of the first spiral bevel gearbox.

[0016] Preferably, a first sprocket and a second sprocket are respectively provided on the top plate of the frame directly above the first spiral bevel gear box and the second spiral bevel gear box, and a rotating rod rotatably connected to the top plate of the frame is respectively provided at the bottom of the first sprocket and the second sprocket, the rotating rod of the first sprocket is connected to the kinetic energy output shaft at the top of the first spiral bevel gear box through a coupling, the rotating rod of the second sprocket is connected to the kinetic energy input shaft at the top of the first spiral bevel gear box through a coupling, and the kinetic energy output shaft on the right side of the first spiral bevel gear box is connected to the screw rod.

[0017] Preferably, a hopper is provided at the top of the left end of the cylindrical crucible, and a discharge port at the bottom of the hopper extends into the interior of the cylindrical crucible, and a distance of a graphite piston thickness is left between the discharge port and the cylindrical crucible.

[0018] Preferably, a sliding contact is fixedly provided on the inner wall of the right side frame of the frame, the conductor on the sliding contact contacts the graphite turntable, and the contact of the sliding contact is connected to the negative pole of the high voltage DC power supply.

[0019] Preferably, the method for mass continuous production of spherical silver powder comprises the following steps:

[0020] Step 1: Place the silver raw material into a cylindrical crucible;

[0021] Step 2: Turn on the switch connecting the tungsten needle and the high-voltage DC power supply. A heating voltage is generated between the tungsten needle and the graphite piston, heating the silver raw material inside the cylindrical crucible. The heating temperature is controlled above 961°C until the silver raw material melts into liquid silver.

[0022] Step 3: When completing step 2, an electric field exists between the tungsten needle and the graphite turntable;

[0023] Step 4: Apply pressure to the graphite piston, causing the liquid silver inside the cylindrical crucible to be ejected from the central hole of the tungsten needle at a rate of 0.1-100 mL / min. Under the action of the electric field, the liquid silver forms a Taylor cone and is ejected, and liquid silver spinning is carried out. The liquid silver thread is a nano-spray thin stream of silver before contacting the graphite turntable;

[0024] Step 5: While the liquid silver is spinning, the graphite turntable is started to rotate, and the speed is controlled between 1000-100000rpm, so that the silver stream moves toward the graphite turntable under the action of the electric field. After contacting the graphite disc, the silver stream is intercepted and separated before solidification. The spherical droplets are formed by the centrifugal action of the graphite turntable and thrown out. During the throwing process, the spherical droplets cool to obtain spherical silver powder, which is then recovered to complete the production of spherical silver powder.

[0025] Preferably, the silver raw material is silver alloy powder or block.

[0026] Preferably, in step five, when the silver thin stream contacts the magnesium oxide on the graphite disk, the intercepted nano-spray thin stream is tumbled to form spherical silver powder by utilizing the liquid / solid non-wetting effect in which magnesium oxide and silver do not wet each other at all.

[0027] Compared with the prior art, the present invention has the following beneficial effects: molten silver is sprayed into nano-spray streams using a cylindrical crucible and a tungsten needle, which are received by a rotating graphite disk coated with a magnesium oxide layer. Under the high-speed rotation of the graphite disk, the silver stream is cut off and separated before solidification. When the silver stream contacts the magnesium oxide layer, the liquid / solid non-wetting effect, in which the magnesium oxide layer and silver do not wet each other at all, is utilized to form spherical silver powder during the tumbling process. The generated silver powder has good sphericity, a smooth surface, and good conductivity. Compared with the general spray pyrolysis method, the problems of poor sphericity and wide particle size distribution are overcome. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a schematic diagram of the overall structure of the equipment for continuous mass production of spherical silver powder in the present invention;

[0029] Figure 2 This is a schematic diagram of the structure of the cylindrical crucible and the graphite piston in the present invention;

[0030] Figure 3Schematic diagram of the operating principle of the equipment for mass continuous production of spherical silver powder in the present invention.

[0031] In the figure: 1. cylindrical crucible; 11. charging hopper; 2. graphite piston; 21. push rod; 22. slide; 221. screw; 222. slider; 23. push plate; 3. tungsten needle; 4. magnesium oxide coating; 5. graphite turntable; 51. rotating mounting cylinder; 6. high-voltage DC power supply; 7. sliding contact; 8. frame; 81. mounting frame; 82. drive table; 83. mounting table; 9. drive motor; 91. first spiral bevel gearbox; 92. first sprocket; 93. second sprocket; 94. second spiral bevel gearbox. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0033] It should be noted that when an element is referred to as being “fixed on” or “disposed on” another element, it may be directly on the other element or indirectly on the other element. When an element is referred to as being “connected to” another element, it may be directly connected to the other element or indirectly connected to the other element.

[0034] In the description of the present invention, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention.

[0035] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature identified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0036] In order to better understand the above technical solution, the above technical solution will be described in detail below with reference to the accompanying drawings and specific implementation methods.

[0037] Example:

[0038] See also Figure 1-3, this embodiment provides a technical solution:

[0039] A device for continuously producing a large amount of spherical silver powder, comprising a cylindrical crucible 1, a tungsten needle 3 arranged at the right end of the cylindrical crucible 1, and a graphite turntable 5 arranged on the right side of the tungsten needle 3;

[0040] The tungsten needle 3 is provided with a central hole along the axis of the tungsten needle 3, and the graphite turntable 5 is perpendicular to the right side of the central hole of the tungsten needle 3 to receive the wire ejected from the central hole;

[0041] Wherein, the tungsten needle 3 is a nano-scale tungsten needle or a micro-scale tungsten needle;

[0042] The cylindrical crucible 1 is loaded with silver raw material, which is melted by electric current and ejected through the central hole of the tungsten needle 3 to be spun into fibers at the outlet end of the tungsten needle 3;

[0043] The surface of the left panel of the graphite turntable 5 is provided with a magnesium oxide coating, and the cylindrical crucible 1 is connected to the tungsten needle 3; specifically, a rotating rod driven by a motor is provided at the center position on the right side of the graphite turntable 5;

[0044] The crucible 1 further includes a high-voltage DC power supply 6, the positive electrode of the high-voltage DC power supply 6 is connected to the tungsten needle 3, the outer shell of the graphite turntable 5 is grounded, a high-voltage electric field is formed between the tungsten needle 3 and the graphite turntable 5, a graphite piston 2 is slidably provided inside the cylindrical crucible 1, the negative electrode of the high-voltage DC power supply 6 is connected to the graphite piston 2, and the graphite piston 2 is in direct contact with the silver raw material;

[0045] Molten silver is sprayed into a nano-spray stream using a cylindrical crucible 1 and a tungsten needle 3, and is received by a rotating graphite disk coated with magnesium oxide. Under the high-speed rotation of the graphite disk, the silver stream is cut off and separated before solidification. When the silver stream contacts the magnesium oxide coating, the liquid / solid non-wetting effect of the magnesium oxide coating and silver is completely non-wetted, so that the cut silver stream forms spherical silver powder during the tumbling process. By controlling parameters such as voltage, nozzle distance, spinning speed and disk rotation speed, the flow size of the cut silver stream is controlled to achieve silver powder size regulation and generate nano- and micron-sized silver powder. The generated silver powder has good sphericity, smooth surface and good conductivity. Compared with the general spray pyrolysis method, the problems of poor sphericity and wide particle size distribution are overcome.

[0046] In this embodiment, a sliding contact 7 is provided on the outer shell of the graphite turntable 5 , and the sliding contact 7 is connected to the grounding circuit of the high-voltage DC power supply 6 .

[0047] In this embodiment, please refer to Figure 1, further comprising a frame 8, a mounting frame 81 for mounting the cylindrical crucible 1 is fixedly provided at the middle position of the bottom plate of the frame 8, a driving table 82 extending to the left end of the frame 8 is fixedly provided at the left end of the mounting frame 81, a second spiral bevel gear box 94 and a chute 22 are fixedly provided on the driving table 82 from left to right, a screw rod 221 is rotatably provided inside the chute 22, and a slider 222 slidably provided in the chute 22 is provided on the screw rod 221, a push plate 23 is fixedly provided on the top of the slider 222, and a push rod 21 connected to the graphite piston 2 is fixedly provided on the push plate 23;

[0048] Furthermore, a rotating mounting cylinder 51 is fixedly provided on the right side frame of the frame 8 and passes through the side frame horizontally. A rotating shaft is provided at the middle of the right end of the graphite turntable 5 and passes through the rotating mounting cylinder 51 and is rotatably connected to the inside of the rotating mounting cylinder 51 through a bearing.

[0049] Furthermore, a mounting table 83 is fixedly provided on the right side frame of the frame 8 below the rotating mounting cylinder 51. A first spiral bevel gearbox 91 and a drive motor 9 are sequentially provided on the mounting table 83 from left to right. The output shaft at the left end of the first spiral bevel gearbox 91 is connected to the shaft of the graphite turntable 5 through a coupling, and the motor shaft of the drive motor 9 is connected to the drive shaft at the right end of the first spiral bevel gearbox 91.

[0050] Furthermore, a first sprocket 92 and a second sprocket 93 are respectively provided on the top plate of the frame 8 directly above the first spiral bevel gear box 91 and the second spiral bevel gear box 94, and a rotating rod rotatably connected to the top plate of the frame 8 is respectively provided at the bottom of the first sprocket 92 and the second sprocket 93. The rotating rod of the first sprocket 92 is connected to the kinetic energy output shaft at the top of the first spiral bevel gear box 91 through a coupling, and the rotating rod of the second sprocket 93 is connected to the kinetic energy input shaft at the top of the first spiral bevel gear box 91 through a coupling. The kinetic energy output shaft on the right side of the first spiral bevel gear box 91 is connected to the screw rod 221;

[0051] Specifically, during use, when the drive motor 9 drives the first spiral bevel gearbox 81 to rotate, the kinetic energy output shaft at the left end of the first spiral bevel gearbox 81 drives the rotating shaft at the right end of the graphite turntable 5 to rotate, thereby driving the graphite turntable 5 to rotate to receive the ejected silver stream;

[0052] At the same time, the kinetic energy output shaft on the top of the first spiral bevel gearbox 81 drives the first sprocket 92 to rotate, and the first sprocket 92 is connected to the second sprocket 93 through a chain, driving the second sprocket 93 to rotate, and the second sprocket 93 drives the second spiral bevel gearbox 94 to rotate, and the second spiral bevel gearbox 94 drives the screw rod 221 to rotate, thereby driving the slider 222 to slide in the slide groove 22, and the slider 222 drives the push plate 23 to displace, and the push plate 23 drives the graphite piston 2 to displace in the cylindrical crucible 1 during the displacement process, thereby realizing the extrusion and ejection of the silver thin stream.

[0053] In this embodiment, a hopper 11 is provided at the top left end of the cylindrical crucible 1, and a discharge port at the bottom of the hopper 11 extends into the interior of the cylindrical crucible 1, and a distance of the thickness of a graphite piston 2 is left between the discharge port and the cylindrical crucible 1. When the graphite piston 2 is moved to the leftmost end of the cylindrical crucible 1, material can be added to the hopper 11.

[0054] In this embodiment, a sliding contact 7 is fixedly provided on the inner wall of the right side frame of the frame 8 , the conductor on the sliding contact 7 contacts the graphite turntable 5 , and the contact of the sliding contact 7 is connected to the negative pole of the high-voltage DC power supply 6 .

[0055] The method for mass continuous production of spherical silver powder comprises the following steps:

[0056] Step 1: Place the silver raw material into a cylindrical crucible;

[0057] Step 2: Turn on the switch connecting the tungsten needle and the high-voltage DC power supply. A heating voltage is generated between the tungsten needle and the graphite piston, heating the silver raw material inside the cylindrical crucible. The heating temperature is controlled above 961°C until the silver raw material melts into liquid silver.

[0058] Step 3: When completing step 2, an electric field exists between the tungsten needle and the graphite turntable;

[0059] Step 4: Apply pressure to the graphite piston, causing the liquid silver inside the cylindrical crucible to be ejected from the central hole of the tungsten needle at a rate of 0.1-100 mL / min. Under the action of the electric field, the liquid silver forms a Taylor cone and is ejected, and liquid silver spinning is carried out. The liquid silver thread is a nano-spray thin stream of silver before contacting the graphite turntable;

[0060] Step 5: While the liquid silver is spinning, the graphite turntable is started to rotate, and the speed is controlled between 1000-100000 rpm, so that the silver stream moves toward the graphite turntable under the action of the electric field. After contacting the graphite disc, the silver stream is intercepted and separated before solidification, and is formed into spherical droplets by the centrifugal action of the graphite turntable and thrown out. During the throwing process, the spherical droplets cool to obtain spherical silver powder, which is recovered to complete the production of spherical silver powder. When the silver stream contacts the magnesium oxide on the graphite disc, the liquid / solid non-wetting effect of magnesium oxide and silver is used to make the intercepted nano-spray stream tumble to form spherical silver powder.

[0061] In this embodiment, the silver raw material is silver alloy powder or block.

[0062] In this embodiment, the voltage of the high-voltage DC power supply 6 is controlled between 10-30 kV, and the distance between the tungsten needle 3 and the graphite turntable 5 can be 5-30 cm.

[0063] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A device for the continuous mass production of spherical silver powder, characterized by: It comprises a cylindrical crucible (1), a tungsten needle (3) arranged at the right end of the cylindrical crucible (1), and a graphite turntable (5) arranged on the right side of the tungsten needle (3); The tungsten needle (3) is provided with a central hole along the axis of the tungsten needle (3), and the graphite turntable (5) is perpendicular to the right side of the central hole of the tungsten needle (3) to receive the wire ejected from the central hole; The cylindrical crucible (1) is loaded with a silver raw material, and the silver raw material is ejected through the central hole of the tungsten needle (3) to be spun at the outlet end of the tungsten needle (3) to form fibers; The surface of the left panel of the graphite turntable (5) is provided with a magnesium oxide coating, and the cylindrical crucible (1) is connected to the tungsten needle (3); It also includes a high-voltage DC power supply (6), the positive electrode of the high-voltage DC power supply (6) is connected to the tungsten needle (3), the outer shell of the graphite turntable (5) is grounded, and the tungsten needle (3), the silver raw material and the outer shell of the graphite turntable (5) form a high-voltage electric field; A graphite piston (2) is slidably provided inside the cylindrical crucible (1), and the negative electrode of the high-voltage DC power supply (6) is connected to the graphite piston (2) and is in electrical contact with the silver raw material; It also includes a frame (8), a sliding contact (7) is fixedly provided on the inner wall of the right side frame of the frame (8), the conductor on the sliding contact (7) is in contact with the graphite turntable (5), and the electrical connector of the sliding contact (7) is connected to the negative electrode of the high-voltage DC power supply (6); The voltage of the high-voltage DC power supply (6) is controlled between 10-30 kV, and the distance between the tungsten needle (3) and the graphite turntable (5) is 5-30 cm.

2. The equipment for continuous mass production of spherical silver powder according to claim 1, characterized in that: A mounting frame (81) for mounting a cylindrical crucible (1) is fixedly provided at the middle position of the bottom plate of the frame (8), a driving table (82) extending to the left end of the frame (8) is fixedly provided at the left end of the mounting frame (81), a second spiral bevel gear box (94) and a slide groove (22) are fixedly provided on the driving table (82) from left to right, a screw rod (221) is rotatably provided inside the slide groove (22), and a slider (222) is provided on the screw rod (221) and is slidably provided in the slide groove (22), a push plate (23) is fixedly provided on the top of the slider (222), and a push rod (21) connected to the graphite piston (2) is fixedly provided on the push plate (23).

3. The equipment for continuous mass production of spherical silver powder according to claim 2, characterized in that: A rotating mounting cylinder (51) is fixedly provided on the right side frame of the frame (8) and passes through the side frame horizontally. A rotating shaft is provided at the middle of the right end of the graphite turntable (5) and passes through the rotating mounting cylinder (51) and is rotatably connected to the inside of the rotating mounting cylinder (51) through a bearing.

4. The equipment for continuous mass production of spherical silver powder according to claim 3, characterized in that: A mounting table (83) is fixedly provided on the right side frame of the frame (8) below the rotating mounting cylinder (51), and a first spiral bevel gear box (91) and a drive motor (9) are sequentially provided on the mounting table (83) from left to right. The output shaft at the left end of the first spiral bevel gear box (91) is connected to the shaft of the graphite turntable (5) through a coupling, and the motor shaft of the drive motor (9) is connected to the drive shaft at the right end of the first spiral bevel gear box (91).

5. The equipment for continuous mass production of spherical silver powder according to claim 4, characterized in that: A first sprocket (92) and a second sprocket (93) are respectively provided on the top plate of the frame (8) directly above the first spiral bevel gear box (91) and the second spiral bevel gear box (94), and a rotating rod rotatably connected to the top plate of the frame (8) is respectively provided at the bottom of the first sprocket (92) and the second sprocket (93), the rotating rod of the first sprocket (92) is connected to the kinetic energy output shaft at the top of the first spiral bevel gear box (91) through a coupling, the rotating rod of the second sprocket (93) is connected to the kinetic energy input shaft at the top of the first spiral bevel gear box (91) through a coupling, and the kinetic energy output shaft on the right side of the first spiral bevel gear box (91) is connected to the screw rod (221).

6. The equipment for continuous mass production of spherical silver powder according to claim 5, characterized in that: A feeding hopper (11) is provided at the top of the left end of the cylindrical crucible (1), and a discharge port at the bottom of the feeding hopper (11) extends into the interior of the cylindrical crucible (1), and a distance of the thickness of a graphite piston (2) is left between the discharge port and the cylindrical crucible (1).

7. A method for continuously producing spherical silver powder in large quantities using the apparatus for continuously producing spherical silver powder in large quantities according to any one of claims 1 to 6, characterized in that: The following steps are involved: Step 1: Place the silver raw material into a cylindrical crucible; Step 2: Turn on the switch connecting the tungsten needle and the high-voltage DC power supply. A heating voltage is generated between the tungsten needle and the graphite piston, heating the silver raw material inside the cylindrical crucible. The heating temperature is controlled above 961°C until the silver raw material melts into liquid silver. Step 3: When completing step 2, an electric field exists between the tungsten needle and the graphite turntable; Step 4: Apply pressure to the graphite piston, causing the liquid silver inside the cylindrical crucible to be ejected from the central hole of the tungsten needle at a rate of 0.1-100 mL / min. Under the action of the electric field, the liquid silver forms a Taylor cone and is ejected, and liquid silver spinning is carried out. The liquid silver thread is a nano-spray thin stream of silver before contacting the graphite turntable; Step 5: While the liquid silver is spinning, the graphite turntable is started to rotate, and the speed is controlled between 1000-100000rpm, so that the silver stream moves toward the graphite turntable under the action of the electric field. After contacting the graphite disc, the silver stream is intercepted and separated before solidification. The spherical droplets are formed by the centrifugal action of the graphite turntable and thrown out. During the throwing process, the spherical droplets cool to obtain spherical silver powder, which is then recovered to complete the production of spherical silver powder.

8. The method for continuous mass production of spherical silver powder according to claim 7, characterized in that: The silver raw material is silver alloy powder or block.

9. The method for continuous mass production of spherical silver powder according to claim 7, characterized in that: In the step 5, when the silver thin stream contacts the magnesium oxide on the graphite disk, the intercepted nano-spray thin stream is rolled to form spherical silver powder by utilizing the liquid / solid non-wetting effect in which magnesium oxide and silver do not wet each other at all.

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