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CN-121988746-A - Powder preparation method and device

CN121988746ACN 121988746 ACN121988746 ACN 121988746ACN-121988746-A

Abstract

The application discloses a powder preparation method which comprises the steps of preparing a silver nitrate solution, ammonia water, alkali liquor, a dispersing agent, a reducing agent and a coating agent, adding the ammonia water into the silver nitrate solution and stirring for 2-10min, adding the alkali liquor into the solution and stirring to keep the pH at 9-11, adding the dispersing agent into the solution and stirring for 5-10min, adding the reducing agent into the solution and stirring for 15-20s, adding the coating agent into the solution and stirring for 10-20min, separating silver simple substances in the reaction solution and conducting drying and dispersing treatment to obtain a silver powder finished product, wherein the reaction temperature of a reaction stage is 10-40 ℃. By adopting the powder preparation method and the device provided by the application, the tap density of the prepared silver powder is more than or equal to 6g/ml, and the tap density is higher, so that the subsequent use of the silver powder is facilitated. Meanwhile, the burning loss of the silver powder finished product is low. The application also discloses a powder preparation device.

Inventors

  • HE JIACHENG
  • NIE HAITAO
  • WU WEIPING

Assignees

  • 广东长信精密设备有限公司

Dates

Publication Date
20260508
Application Date
20260113

Claims (10)

  1. 1. A method for preparing powder, comprising the steps of: S100, preparing silver nitrate solution, ammonia water, alkali liquor, dispersing agent, reducing agent and coating agent; S200, reaction stage: s210, adding ammonia water into the silver nitrate solution and stirring, wherein the reaction time is 2-10min; S220, adding alkali liquor into the solution and stirring to keep the pH value at 9-11; s230, adding a dispersing agent into the solution and stirring, wherein the reaction time is 5-10min; S240, adding a reducing agent into the solution and stirring, wherein the reaction time is 15-20S; s250, adding a coating agent into the solution, and stirring for 10-20min; S300, a post-treatment stage, namely separating silver simple substances in the reaction solution, and performing drying and dispersing treatment to obtain a silver powder finished product; Wherein the reaction temperature of the reaction stage is 10-40 ℃.
  2. 2. The powder preparation method according to claim 1, wherein the preparation step of the silver nitrate solution comprises adding pure water into silver nitrate under nitrogen atmosphere, stirring and dissolving, and controlling the solution temperature at 10-40 ℃; the preparation method of ammonia water comprises adding concentrated ammonia water into pure water, mixing, and controlling ammonia water temperature at 10-40deg.C; the alkali solution is prepared by adding sodium hydroxide into pure water, stirring for dissolving, and controlling the temperature of the solution at 10-40 ℃; The preparation method of the dispersing agent comprises the steps of adding the dispersing material into absolute ethyl alcohol, stirring and dissolving, and controlling the temperature of the solution at 10-40 ℃; the preparation method of the reducing agent comprises adding the reducing substance into pure water, mixing and stirring, and controlling the solution temperature at 10-40deg.C; the preparation process of the coating agent includes adding coating material into absolute alcohol, stirring to dissolve and controlling the temperature of the solution at 10-40 deg.c.
  3. 3. The powder production method according to claim 2, wherein the dispersion substance is one or more of PEG, PVP, PAA.
  4. 4. The powder preparation method according to claim 2, wherein the reducing substance is one or more of formaldehyde, paraformaldehyde, hydrazine hydrate, glucose, ascorbic acid or a corresponding aqueous solution.
  5. 5. The powder production method according to claim 2, wherein the coating substance is one or more of lauric acid, stearic acid, oleic acid, fatty alcohol.
  6. 6. The powder production method according to claim 1, wherein S300 comprises the steps of: s310, carrying out solid-liquid separation on the solution; S320, washing the solid material with water; S330, centrifuging the solid material to obtain a filter cake; S340, drying the filter cake; S350, crushing and screening the filter cake to obtain a silver powder finished product.
  7. 7. The powder production method according to claim 6, wherein in S320, the filter cake is washed with water until the conductivity of the washing water is <10us/cm.
  8. 8. A powder preparation apparatus for carrying out the powder preparation method according to any one of claims 1 to 7, comprising: A reaction kettle; the storage tanks are respectively used for storing ammonia water, alkali liquor, dispersing agents, reducing agents and coating agents, and each storage tank is connected with the reaction kettle; the solid-liquid separation mechanism is arranged at the downstream of the reaction kettle; the dryer is arranged at the downstream of the solid-liquid separation mechanism; And the pulverizer is arranged at the downstream of the dryer.
  9. 9. The powder preparing device of claim 8, further comprising a transfer mechanism disposed between the reaction vessel and the solid-liquid separation mechanism.
  10. 10. The powder preparation device according to claim 8, further comprising a heat exchange mechanism, wherein a jacket space is provided outside the reaction kettle and each of the tanks, and the heat exchange mechanism is connected to the jacket space and is configured to provide a heat exchange medium flowing in a circulating manner to the jacket space.

Description

Powder preparation method and device Technical Field The application belongs to the technical field of metal powder preparation, and particularly relates to a powder preparation method and device. Background Silver powder is a common metal powder in the electronic industry, has excellent heat and electric conduction performance, and is widely applied to industries such as electronics and semiconductors, photovoltaics, fuel cells, lithium ion batteries and the like. The superfine silver powder is silver powder with the particle size between nanometer and submicron, and has the characteristics of high sintering activity, compact sintering, controllable specific surface area and morphology and the like. The current production method of superfine silver powder comprises a liquid phase method, a gas phase method and a solid phase method. Among them, the liquid phase method is the most widely used preparation method because of simple operation process, small investment, large output and small loss. The principle of the liquid phase method is that silver ions are reduced into metallic silver atoms by using a reducing agent, and then the silver atoms are aggregated and deposited in a powder form. For example, the Chinese patent application with publication number CN116967461A discloses a preparation method of high-dispersion low-burning-loss superfine silver powder, the morphology of the superfine silver powder prepared by the method is spheroid, the particle size of D50 is regulated and controlled between 0.4 and 1.2 mu m, the tap density is 4.0 to 5.0g/cm < 3 >, and the burning loss rate is less than or equal to 0.5 percent. The superfine silver powder prepared by the method has low tap density, and is unfavorable for subsequent use, such as powder metallurgy, electrode materials and the like. Disclosure of Invention The application aims to solve the technical problem that the tap density of silver powder prepared by the existing superfine silver powder preparation method is low, and provides a powder preparation method and device capable of improving the tap density of silver powder. The technical scheme provided by the application is as follows: a method of preparing a powder comprising the steps of: S100, preparing silver nitrate solution, ammonia water, alkali liquor, dispersing agent, reducing agent and coating agent; S200, reaction stage: s210, adding ammonia water into the silver nitrate solution and stirring, wherein the reaction time is 2-10min; S220, adding alkali liquor into the solution and stirring to keep the pH value at 9-11; s230, adding a dispersing agent into the solution and stirring, wherein the reaction time is 5-10min; S240, adding a reducing agent into the solution and stirring, wherein the reaction time is 15-20S; s250, adding a coating agent into the solution, and stirring for 10-20min; S300, a post-treatment stage, namely separating silver simple substances in the reaction solution, and performing drying and dispersing treatment to obtain a silver powder finished product; Wherein the reaction temperature of the reaction stage is 10-40 ℃. Further, the preparation of the silver nitrate solution comprises the steps of adding pure water into silver nitrate under the nitrogen atmosphere, stirring and dissolving, and controlling the temperature of the solution to be 10-40 ℃; the preparation method of ammonia water comprises adding concentrated ammonia water into pure water, mixing, and controlling ammonia water temperature at 10-40deg.C; the alkali solution is prepared by adding sodium hydroxide into pure water, stirring for dissolving, and controlling the temperature of the solution at 10-40 ℃; The preparation method of the dispersing agent comprises the steps of adding the dispersing material into absolute ethyl alcohol, stirring and dissolving, and controlling the temperature of the solution at 10-40 ℃; the preparation method of the reducing agent comprises adding the reducing substance into pure water, mixing and stirring, and controlling the solution temperature at 10-40deg.C; the preparation process of the coating agent includes adding coating material into absolute alcohol, stirring to dissolve and controlling the temperature of the solution at 10-40 deg.c. Further, the dispersed substance is one or more of PEG, PVP, PAA. Further, the reducing substance is one or more of formaldehyde, paraformaldehyde, hydrazine hydrate, glucose and ascorbic acid or a corresponding aqueous solution. Further, the coating substance is one or more of lauric acid, stearic acid, oleic acid and fatty alcohol. Further, S300 includes the steps of: s310, carrying out solid-liquid separation on the solution; S320, washing the solid material with water; S330, centrifuging the solid material to obtain a filter cake; S340, drying the filter cake; S350, crushing and screening the filter cake to obtain a silver powder finished product. Further, in S320, the filter cake is washed with water until the conductivity of th