Investigation on the garnierite and limonite mixed laterite ore for nickel recovery

Abstract

Laterite, as an important resource of nickel, has become the focus of development and utilization. This study adopted the method of mixing ore (garnierite and limonite) to increase the recovery rate of nickel in garnierite ore. The phase transformation of the two ores was investigated during the heating process; dehydroxylation and recrystallization were observed and the iron oxides phase was finally transformed into the iron-containing spinel. By changing the proportion of the two ores, increasing the iron content in the sample was beneficial to the reduction of nickel. Then, Fe2O3, Fe3O4, and Fe were used as the iron source to study the mechanism of the iron-bearing minerals in promoting the reduction of nickel. The results indicated that hematite and/or magnetite would react with amorphous silicate minerals to generate magnesioferrite and enstatite, thereby avoiding additional forsterite generation; moreover, the trevorite phase would be formed, which strengthens the aggregation of nickel and iron.

Keywords

• garnierite ore
• limonite ore
• reduction
• phase transformation