A two-stage reduction process for the production of high-purity ultrafine Ni particles in a micro-fluidized bed reactor--颗粒学报PARTICUOLOGY

Li, J., Liu, X., Zhou, L., Zhu, Q., & Li, H. (2015). A two-stage reduction process for the production of high-purity ultrafine Ni particles in a micro-fluidized bed reactor. Particuology, 19, 27–34. https://doi.org/10.1016/j.partic.2014.04.008

A two-stage reduction process for the production of high-purity ultrafine Ni particles in a micro-fluidized bed reactor

Jun Li, Xinwei Liu, Li Zhou, Qingshan Zhu^*, Hongzhong Li

State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China

10.1016/j.partic.2014.04.008

Volume 19, April 2015, Pages 27-34

Received 17 December 2013, Revised 28 March 2014, Accepted 2 April 2014, Available online 20 July 2014.

E-mail: qszhu@ipe.ac.cn

Highlights

• High purity and low density ultrafine nickel powder was prepared by a two-stage reduction process.

• Formation of agglomerated Ni particles at lower temperatures was crucial to avoiding defluidization.

• A concept design of a two-stage fluidized bed reactor process was proposed for Ni production.

• This method may be extended to synthesis of other nanoparticles.

Abstract

A novel two-stage reduction process for synthesis of ultrafine nickel powder with a high purity and low density in a fluidized bed reactor has been developed in this work. The raw ultrafine NiO particles are first pre-reduced using hydrogen at lower temperatures (340–400 °C), followed by further reduction at higher temperatures (500–600 °C). The self-agglomeration of Ni particles formed during low-temperature reduction decreases the sintering activity of the newly formed ultrafine Ni particles, leading to good fluidization quality, even for the subsequent high-temperature reduction process. The agglomerated Ni particles have a high Ni content (above 99 wt%), a low density (0.78 g/cm³) and a uniform particle size (approximately 100 μm). A concept design for a novel two-stage fluidized bed reactor process used to produce high-purity Ni powder was also proposed. This approach may be extended to the synthesis of other ultrafine/nanosized metals or metal oxides through a fluidization method.

Graphical abstract

Keywords

Ultrafine Ni powder; Production; Fluidized bed reactor; Two-stage reduction

文章导读