Effect of CaF2 on the aggregation and growth of ferronickel particles in the self-reduction of Nickel laterite ore

Abstract

Increasing attention is being paid to the self-reduction and magnetic separation of nickel laterite ore because of economic and efficiency advantages. The aggregation and growth of ferronickel particles during the reduction process is an important factor for subsequent magnetic separation. In this study, the effect of CaF2 on ferronickel particle aggregation and growth during the self-reduction of nickel laterite ore was investigated by visual data analysis of ferronickel particles. The recovery and grade of Ni and Fe from the self-reduction, fine grinding, and magnetic separation of nickel laterite ore under the strengthening action of CaF2 were measured. Increasing CaF2 addition yielded a significant increase in the average particle size of ferronickel particles and an increased recovery of a higher grade of Ni. A ferronickel concentrate with 7.1 wt% Ni and 68.5 wt% Fe was obtained at a Ni recovery of 84.14% in the presence of 8 wt% CaF2. CaF2 accelerates the aggregation and growth of ferronickel particles, which promotes the separation of the ferronickel alloy from the gangue in the magnetic separation process.