CN-121988750-A - System and method for preparing rapid-mixing continuous silver powder

CN121988750ACN 121988750 ACN121988750 ACN 121988750ACN-121988750-A

Abstract

The invention belongs to the technical field of silver powder production, and particularly relates to a rapid-mixing continuous silver powder preparation system and method; the silver powder synthesizing device comprises a silver nitrate base solution preparing kettle, a reducing agent preparing kettle and a micro-flow rate mixer, wherein the silver nitrate base solution preparing kettle and the reducing agent preparing kettle are respectively communicated with the micro-flow rate mixer, the micro-flow rate mixer is communicated with a vacuum belt filter, a pure water storage tank is communicated with the vacuum belt filter, an ethanol storage tank is communicated with the vacuum belt filter, a belt silver powder dryer is connected with a silver powder discharging end of the vacuum belt filter, a silver powder fluidization supply device is connected with a silver powder discharging end of the belt silver powder dryer, and a silver powder fluidization supply device is connected with a honeycomb mill.

Inventors

DING CHENG
WANG JU

Assignees

长春黄金研究院有限公司

Dates

Publication Date: 20260508
Application Date: 20260410

Claims (10)

1. A rapid mixing continuous silver powder production system, comprising: the silver powder synthesis module comprises at least two silver nitrate base solution preparation kettles arranged in parallel, at least two reducing agent preparation kettles arranged in parallel and a micro-flow rate mixer, wherein a liquid outlet of the silver nitrate base solution preparation kettles and a liquid outlet of the reducing agent preparation kettles are communicated with a liquid inlet of the micro-flow rate mixer through a silver nitrate metering pump and a reducing agent metering pump respectively; The silver powder purifying and washing module comprises a vacuum belt filter, a pure water storage tank and an ethanol storage tank, wherein a liquid outlet of a micro-flow rate mixer is communicated with a slurry inlet of the vacuum belt filter; the feeding end of the belt type silver powder dryer is connected with the silver powder discharging end of the vacuum belt type filter; The silver powder depolymerization post-treatment module comprises a silver powder fluidization supply device and a honeycomb mill, wherein the feeding end of the silver powder fluidization supply device is connected with the discharging end of the belt type silver powder dryer, and the discharging end of the silver powder fluidization supply device is communicated with the feeding port of the honeycomb mill.
2. The rapid mixing continuous silver powder production system of claim 1, wherein the micro-flow mixer comprises: The top of the tubular composite body is provided with a slurry liquid outlet which is communicated with a slurry inlet of the vacuum belt filter; a stirrer mounted inside the tubular synthesis body below; the variable frequency driver is fixed at the bottom of the tubular composite body, and a transmission shaft of the variable frequency driver is connected with the stirrer; The concentric tube mixer is arranged at the lower part of the tube type composite body in a penetrating way and matched with the stirrer, one end of the concentric tube mixer is respectively provided with a silver nitrate base solution inlet and a reducing agent liquid inlet, the silver nitrate base solution inlet is communicated with a liquid outlet of a silver nitrate metering pump, and the reducing agent liquid inlet is communicated with a liquid outlet of a reducing agent metering pump.
3. The rapid mixing continuous silver powder preparation system according to claim 2, wherein the micro-flow rate mixer further comprises a constant temperature heat exchange shell, wherein the constant temperature heat exchange shell is sleeved on the outer side of the tubular composite body, and a heat exchange liquid inlet and a heat exchange liquid outlet are formed in the constant temperature heat exchange shell.
4. The rapid mixing continuous silver powder production system of claim 3, further comprising a constant temperature heat exchanger, wherein a liquid outlet of the constant temperature heat exchanger is communicated with the heat exchange liquid inlet, and a liquid return port of the constant temperature heat exchanger is communicated with the heat exchange liquid outlet.
5. The rapid mixing continuous silver powder preparation system according to claim 2, wherein a slurry distributor is sequentially arranged above the vacuum belt filter along the conveying direction of the vacuum belt filter and is communicated with a slurry outlet of the micro-flow rate mixer; and a waste liquid collector is arranged below the vacuum belt filter and is used for collecting waste liquid generated by filtering and washing.
6. The rapid mixing continuous silver powder preparation system according to claim 5, wherein the silver powder purification washing module further comprises a negative pressure tank and a vacuum generator, wherein the waste liquid collector is communicated with one end of the negative pressure tank through a pipeline, and the other end of the negative pressure tank is communicated with the vacuum generator.
7. The rapid mixing continuous silver powder production system of claim 1, wherein the silver powder fluidization supply device comprises: The feed inlet of the silver powder stirring bin is connected with the discharge end of the belt type silver powder dryer; the spiral feeder is arranged at a bottom discharge hole of the silver powder stirring bin; the silver powder jet device is characterized in that the feeding end of the silver powder jet device is connected with the discharging end of the screw feeder, the air outlet of the air blower is connected with the air inlet of the silver powder jet device, and the discharging end of the silver powder jet device is communicated with the feeding port of the honeycomb mill.
8. The rapid-mixing continuous silver powder preparation system according to claim 1, wherein the silver powder depolymerization post-treatment module further comprises a silver powder cyclone separator, a dust remover and a negative pressure induced draft fan, wherein a feed inlet of the silver powder cyclone separator is communicated with a discharge hole of a honeycomb mill, an air inlet of the dust remover is communicated with an air outlet of the silver powder cyclone separator, and an air inlet of the negative pressure induced draft fan is communicated with an air outlet of the dust remover.
9. A method for preparing silver powder by using the rapid-mixing continuous silver powder preparation system according to any one of claims 1 to 8, comprising the following steps: Step S1, alternately and continuously providing silver nitrate base solution through at least two silver nitrate base solution preparation kettles arranged in parallel, alternately and continuously providing reducing agent solution through at least two reducing agent preparation kettles arranged in parallel; step S2, metering the silver nitrate base solution and the reducing agent solution respectively through a silver nitrate metering pump and a reducing agent metering pump, simultaneously feeding the silver nitrate base solution and the reducing agent solution into a micro-flow-rate mixer, carrying out rapid mixing reaction under the stirring condition, generating silver powder slurry, and discharging; Step S3, conveying the silver powder slurry discharged in the step S2 to a vacuum belt filter, and sequentially carrying out mother liquor separation, pure water washing and ethanol washing under a negative pressure condition to obtain purified wet silver powder and discharging the purified wet silver powder; s4, conveying the purified wet silver powder discharged in the step S3 to a belt type silver powder dryer for drying to obtain dry silver powder; and S5, conveying the dried silver powder discharged in the step S4 to a silver powder fluidization supply device, stirring, scattering and conveying the silver powder into a honeycomb mill, and carrying out depolymerization and modification treatment to obtain a target silver powder product.
10. The method for preparing silver powder according to claim 9, wherein the step S2 is specifically that after the silver nitrate base solution and the reducing agent solution are respectively metered by a silver nitrate metering pump and a reducing agent metering pump, the silver nitrate base solution and the reducing agent solution are simultaneously fed into the tubular synthesis body through a concentric tube mixer, and are stirred and mixed by a stirrer to generate silver powder slurry and are discharged from a slurry liquid outlet of the tubular synthesis body; The silver powder slurry discharged from a slurry liquid outlet is conveyed to a slurry distributor, discharged materials discharged from the slurry distributor fall into a vacuum belt filter, the silver powder slurry is subjected to solid-liquid separation through the vacuum belt filter, and mother liquor after the solid-liquid separation of the vacuum belt filter is pumped into a waste liquor collector for collection under the action of negative pressure liquid pumping of a vacuum generator, so that silver powder and mother liquor of silver powder synthetic liquor are separated; Along with the belt conveying of the vacuum belt filter, the silver powder after mother liquor separation is conveyed by the belt of the vacuum belt filter, moves to the lower part of a washing water distributor, at the moment, washing liquid in a pure water storage tank enters the washing water distributor through a pure water pump, the washing water distributor sprays the washing liquid to the silver powder at the corresponding position on the vacuum belt filter below the washing water distributor, after the silver powder is washed by water through the vacuum belt filter, the silver powder moves to the lower part of a washing ethanol distributor again under the belt conveying of the vacuum belt filter, at the moment, the ethanol solution in the ethanol storage tank enters the washing ethanol distributor through an ethanol pump, the washing ethanol distributor sprays the ethanol solution to the washed silver powder at the corresponding position on the vacuum belt filter below the washing ethanol distributor, the ethanol dehydration purification washing of the silver powder is completed through the vacuum belt filter, and purified wet silver powder is obtained and discharged into a belt dryer; The silver powder drying process comprises the steps of enabling the silver powder dried by a belt type silver powder dryer to enter a silver powder stirring bin, scattering silver powder agglomeration under the action of a stirrer in the silver powder stirring bin, enabling the scattered silver powder to be fed into a silver powder jet device through a spiral feeder, starting a blower at the same time, conveying the silver powder to a honeycomb mill through wind power, enabling microscopic depolymerization, homogenization, polishing spheroidization and modification coating of the silver powder under the action of the honeycomb mill, enabling the treated silver powder to enter a silver powder cyclone separator through a discharge hole of the honeycomb mill, carrying out silver powder and gas separation operation in the silver powder cyclone separator, enabling separated target silver powder to fall into a silver powder product collecting storage tank at the bottom of the silver powder cyclone separator, discharging and collecting separated gas through a discharge hole of the silver powder cyclone separator, enabling the gas to enter the dust remover through an air outlet of the silver powder cyclone separator under the action of a negative pressure induced draft fan, and exhausting air through a negative pressure induced draft fan.

Description

System and method for preparing rapid-mixing continuous silver powder Technical Field The invention belongs to the technical field of silver powder production, and particularly relates to a rapid-mixing continuous silver powder preparation system and method. Background Silver powder (generally referred to as silver metal powder) is a core support process in the fields of electronic paste, photovoltaic conductive materials, microelectronic components and the like. At present, the most mainstream silver powder preparation method in industrial production is a chemical reduction method, namely, silver ions in silver nitrate or silver ammonia solution are reduced into elemental silver particles by a reducing agent (such as hydrazine hydrate, glucose, ascorbic acid and the like), and the particle size, morphology (such as spheres and flakes) and crystallinity of the powder are controlled by regulating and controlling reaction conditions. The method has the advantages of mature process, strong controllability, suitability for large-scale production and the like. The silver powder is prepared by essentially taking silver salt, a reducing agent and a dispersing agent as main raw materials, and reducing, nucleating and growing silver ions into powder particles with specific size, morphology and surface characteristics under specific reaction conditions. In the laboratory research stage, the scale of the silver powder preparation device varies according to research targets, yield requirements and funding conditions, and the silver powder preparation device comprises various forms from a simple beaker reaction to a pilot scale reaction kettle. However, continuous and unmanned industrial production from full processes of medicament addition, silver powder synthesis, solid-liquid separation, washing purification, drying dispersion, depolymerization modification and the like are not realized in the industry at present. The existing production line still depends on manual intervention in a plurality of links, so that the stability among batches is insufficient, the production efficiency is limited, and the severe requirement of the high-end application field on the consistency of the silver powder performance is difficult to meet. Therefore, in order to break through the bottleneck of the existing silver powder preparation process and improve the industrialized production capacity and the product performance stability, development of an industrial silver powder preparation production line with continuous operation capacity is needed to promote silver powder manufacturing to be upgraded in the automatic, standardized and efficient directions. Disclosure of Invention In order to overcome the problems, the invention provides a rapid-mixing continuous silver powder preparation system and a rapid-mixing continuous silver powder preparation method, which realize continuous production of the whole process of medicament addition, rapid synthesis preparation, solid-liquid separation, washing purification, drying, scattering and depolymerization modification in the silver powder preparation process. In order to achieve the above purpose, the technical scheme of the invention is as follows: A rapid mixing continuous silver powder production system comprising: the silver powder synthesis module comprises at least two silver nitrate base solution preparation kettles arranged in parallel, at least two reducing agent preparation kettles arranged in parallel and a micro-flow rate mixer, wherein a liquid outlet of the silver nitrate base solution preparation kettles and a liquid outlet of the reducing agent preparation kettles are communicated with a liquid inlet of the micro-flow rate mixer through a silver nitrate metering pump and a reducing agent metering pump respectively; The silver powder purifying and washing module comprises a vacuum belt filter, a pure water storage tank and an ethanol storage tank, wherein a liquid outlet of a micro-flow rate mixer is communicated with a slurry inlet of the vacuum belt filter; the feeding end of the belt type silver powder dryer is connected with the silver powder discharging end of the vacuum belt type filter; The silver powder depolymerization post-treatment module comprises a silver powder fluidization supply device and a honeycomb mill, wherein the feeding end of the silver powder fluidization supply device is connected with the discharging end of the belt type silver powder dryer, and the discharging end of the silver powder fluidization supply device is communicated with the feeding port of the honeycomb mill. The micro-flow mixer includes: The top of the tubular composite body is provided with a slurry liquid outlet which is communicated with a slurry inlet of the vacuum belt filter; a stirrer mounted inside the tubular synthesis body below; the variable frequency driver is fixed at the bottom of the tubular composite body, and a transmission shaft of the variable frequency driver is conn