• Hydrogen pre-reduction of Nchwaning manganese ore effectively reduces higher manganese oxides to MnO, with smaller particle sizes and higher temperatures enhancing the reduction degree.
• The use of hydrogen as a reductant in manganese ore pre-reduction can significantly reduce CO2 emissions compared to conventional carbon-based processes.
• Decrepitation of ore particles during reduction was measured, providing insights into particle stability and process optimization.
• The study demonstrates that complete pre-reduction to MnO is achievable, which is critical for minimizing aluminum consumption in downstream processes like the HalMan process.