Preparation of an ultrafine nickel powder by solid-phase reduction with a NaCl separator agent.

• A new idea for the preparation of ultrafine nickel powder. • The interaction among primary nickel particles can isolated by NaCl. • NaCl can prevents agglomeration among the primary nickel particles. • Particle size of the obtained nickel powder is nearly spherical. This paper explored a solid-phase reduction method to prepare ultrafine nickel powder under different conditions. The effect of a NaCl separator agent on the morphology, primary particle size and specific surface area of the prepared nickel powder is discussed. The results show that direct contact among primary Ni particles can be effectively inhibited during the reduction of nickel oxalate due to the presence of the NaCl separator agent. An ultrafine nickel powder with a primary particle size of between 80 and 150 nm can be prepared with NaCl as the separator agent at temperatures from 400 °C to 460 °C. The powder reduced at 430 °C has a uniform particle distribution and a decreased amount of agglomeration. [ABSTRACT FROM AUTHOR]