Reduction of limonite ore from South Sulawesi with additive Na₂SO₄ using carbon monoxide

This study utilised a selective reduction method to generate ferronickel from limonitic ore, followed by a magnetic separation stage. The research explored the kinetics and the influence of time and temperature on nickel content and recovery. Sodium sulfate was incorporated as an additive, and carbon monoxide (CO) gas served as the reductant in a vertical tube furnace. Magnetic separation employed a permanent magnet set at 500 G. Reduction took place at temperatures of 900°C, 1000°C, and 1100°C, with varying durations from 30 min to 180 min. Optimal recovery and nickel grade were achieved at 1100°C for 180 min, reaching 70.07% and 8.49%, respectively. Increasing the reduction temperature and time correlated with enhanced recovery and nickel grade.