Study of temperature and holding time of second stage in two-stages thermal upgrading of lateritic nickel ore

Abstract

A two-stage thermal upgrading process with the addition of 10 wt.% sodium sulfate and sodium chloride followed by magnetic separation was conducted for treatment low-grade nickeliferous laterite ore to produce a ferronickel product. The aim of this experiment was to investigate the effect of reduction temperature and holding time in two-stage thermal upgrading process, which was carried out from 950°C to 1150°C for 30 to 90 minutes, into the grade and recovery of nickel also the morphology of ferronickel particle. A wet magnetic separation with 500 gauss magnet was conducted to produce ferronickel in concentrate. Increasing the reduction temperature of nickel laterite increased the nickel grade and recovery. The nickel grade and recovery also increased along with the longer holding time in the reduction process. Nevertheless, it decreased the iron recovery.