Kinetics study on the H2 reduction of Nchwaning manganese ore at elevated temperatures

• Hydrogen reduction of Nchwaning manganese ore at 800–900°C effectively converts Fe2O3 to metallic iron and Mn2O3 to MnO, enabling a sustainable ferromanganese production route. • The HAlMan process can reduce CO2 emissions by approximately 1.5 tonnes per tonne of ferromanganese produced, offering a significant environmental benefit. • Kinetic analysis using a second-order reaction model yields apparent activation energies of 29.79 kJ/mol for dried ore and 61.71 kJ/mol for pre-calcined ore, indicating temperature-dependent reduction kinetics. • The rate-limiting step is identified as the chemical reaction at the gas–solid interface, providing critical insights for process optimization in industrial applications.