Hydrogen-assisted mineral phase transformation for iron recovery and sulfur removal from laterite nickel ore tailings

• Hydrogen-assisted mineral phase transformation enables efficient iron recovery (90.11%) from laterite nickel ore tailings, achieving a final iron grade of 61.00 wt%. • Pre-treatment at 950°C for 15 min reduces sulfur content from 2.09 wt% to 0.295 wt%, mitigating environmental hazards. • Synergistic desulfurization using wet scrubbing and limestone achieves an overall desulfurization rate of 85.83%. • The process offers a sustainable route for valorizing HPAL tailings, with potential for industrial scale-up.