The application of ultrafine nickel powder in various fields

Nickel metal through crushing, grinding processed into nickel powder is a remarkably versatile metal powder materials, due to the magnetic properties, ultrafine nickel powder can be used as magnetic materials, the ultrafine pigment level products in the security printing inks have good role. Nickel powder for metal carbides and graphite having good wettability and good suppression performance, tsintering properties, etc, thus it is an important carbide and diamond matrix bonding metal powder material.

Ultrafine nickel powder is a nano-metal materials, with a series of unique physical and chemical properties: ultrafine nickel powder has high surface activity, large surface area, is a good catalyst, use nickel powder to make nano-composite catalyst can make organics plushydrogen or the efficiency of the dehydrogenation reaction was increased by 10 times than the conventional nickel agent; ultrafine nickel powder has a good conductivity, low cost, is widely used in the conductive paste, a multilayer ceramic capacitor and a nickel-cadmium battery electrodes, etc, the nanonickel powder being applied to the nickel-metal hydride battery, also the direction of the nickel metal hydride batteries developing. In solid propellant of rocket launch satellites, adding about 1% of the nano-nickel, can be tripled its fuel value. So that ultrafine nickel powder in the catalyst sintering activator, conductive paste, battery, carbide has broad application prospects. China have rich nickel resources and strong nickel smelting capacity, automotive, electronics, machinery, information industry development momentum catch worldwide attention, the applications of nickel powder continue to broaden and extend. If in nickel powder, especially in the preparation and application of ultrafine nickel powder have progress, it will important to have full use of resources, and improve economic efficiency.

The nickel powder production method has a lot, there are having electrolytic production nickel powder, a solution containing Ni ions added in an electrolytic cell, use graphite or a noble metal as an electrode, the power is turned on, and periodically changing the direction of current. Electrolyzing a period of time can use magnetic material to collect a nickel powder in the bottom of electrolytic cell. The morphology and size of the nickel powder can be controlled by changing the current conditions. The method is a commonly used method in the industry, but the drawback is the prepared nickel powder coarse, high energy consumption. Electrolytic production of nickel powder have high purity, particle size and bulk density can be controlled, dendritic particles, large surface area and excellent performance of repression and sintering properties, has an important use in the powder metallurgy industry. Currently, the production of electrolytic nickel powder mainly used full chlorine electrolyte, also have the report about using high chloride electrolyte.

The mechanical crushing method: refers to use mechanical force broken large solid into the desired particle size processing method. Different by the mechanical force can be divided into mechanical impact pulverization method, air pulverization method, ball milling and ultrasonic pulverization method. Currently, ball milling method is the most using mechanical method in preparing ultrafine nickel powder. The advantage of this method is capable of continuous operation, production capacity is large, but the morphology of the powder is difficult to control, while the range of particle size distribution is unevenness. Now is still at the experimental stage.

Solid-phase reduction: heated decompose nickel carbonate or nickel oxalate to get nickel oxide, and then nickel oxide use activated carbon reduction can be obtained metallic nickel powder. But while using activated carbon as a reductant, the reaction is slow, and the resulting nickel powder susceptible to contaminate by carbon.

Source:http://www.mhcmp.com