Method for preparing nano nickel powder

Abstract

The invention provides a method for preparing nano nickel powder. The method comprises the following steps of: mixing nickel nitrate, nickel sulfate or nickel chloride and NaOH or KOH, and dissolving in deionized water to prepare deionized solution; adding surfactant into the solution to obtain stable and uniform Ni(OH)2 colloid; mixing the Ni(OH)2 colloid, a reducing agent NaBH4, or N2H4.H2O, and adding catalyst to prepare Ni(OH)2 size; placing the Ni(OH)2 size into a fluidized bed reactor at the temperature of between 50 and 120 DEG C, and reducing for 1 to 30 minutes, and cooling and suction-filtering to obtain the nickel powder with the grain size of between 20 and 100nm; and desalting the residual reaction liquid and then returning to the fluidized bed reactor. The process can run stably and continuously, is low in energy consumption, is environment-friendly, and achieves zero emission, and the industrial water can be recycled.

Description

technical field [0001] The invention relates to the technical field of nano nickel powder, in particular to a preparation method of nano nickel powder. Background technique [0002] With the miniaturization, ultra-large, and integrated development of electronic technology, electronic components will become smaller and smaller, and the nickel powder used as electronic paste is also required to reach nanoscale particles; nano-nickel powder is also due to its high Its reactivity and sintering activity can be used as petroleum cracking catalysts, fine organic synthesis catalysts, rocket fuel catalysts, etc. Different fields have different requirements for the performance of nickel powder, so its preparation methods are also different, but its application is very large. The extent depends on the economy of the production method, and its preparation method is nothing more than physical and chemical methods. [0003] The physical method is to use external physical force to crush m...

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Problems solved by technology

[0003] The physical method is to use external physical force to crush metal nickel powder into fine particles. The typical atomization method and evaporation-condensation method, among them, the atomization method is a method commonly used in industry at present. In the process, the metal nickel is first melted, Then water or gas atomization, the nickel powder prepared by this method is spherical, but the particles are not easy to control

Evaporation-condensation method is to heat metal nickel to 1425°C to vaporize, and then quickly condense the steam to produce nickel powder. The disadvantages of this method are: low production efficiency, easy oxidation of particles, complicated equipment, high technical requirements, and high cost , so it is difficult to achieve industrial production

[0004] Chemical methods include carbonyl nickel thermal decomposition method, high-pressure hydrogen reduction method, ultrasonic atomization-thermal decomposition method, etc. The carbonyl nickel thermal decomposition method was first proposed by Mond, England, and has now been industrialized. At present, Canada, the United Kingdom, the United States, Russia Other countries use this method to produce nickel carbonyl. There are two disadvantages in this method: one is that the decomposition temperature in the pyrolysis tower is relatively high, and the nickel powder is easy to sinter, so the particle size is relatively large; the other is that nickel carbonyl is a highly toxic substance. , which is harmful to human health and causes great pollution to the environment

The high-pressure hydrogen reduction method is to reduce the ammoniacal aqueous solution of nickel or water-insoluble basic nickel carbonate, nickel hydroxide and other water slurries in the presence of a catalyst in an autoclave, and the average particle size of 1.0~1.2um can be obtained. Nickel powder, the high-pressure hydrogen reduction method is simple to operate, low in cost, and easy to promote in industry, but high-pressure equipment and catalyst must be used

The ultrasonic atomization-thermal decomposition method utilizes the high-energy dispersion mechanism of ultrasonic waves. The mother liquid of the target precursor passes through the ultrasonic atomizer to produce micron-sized mist droplets, which are brought into the high-temperature reactor by the carrier gas for thermal decomposition to obtain ultra-uniform particle size. For fine powder materials, the target composition is easy to control and the precursors are easy to obtain when using this method, but it is difficult to realize industrialization and mass production due to the difficulty of large-scale ultrasonic equipment

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