EXPERIMENTAL EVALUATION OF AGRICULTURAL BIOMASS-BASED REDUCTANT FOR SUSTAINABLE FERROALLOY SMELTING

The South African ferroalloy industry faces increasing environmental pressures to transition toward sustainable metallurgical practices. Traditional smelting relies heavily on fossil-based reductants and fluxing agents, contributing significantly to carbon emissions. This study investigates the capabilities of macadamia nutshell biochar as an alternative reductant in ferromanganese production. High-grade manganese ore was crushed and pulverized to ~75 μm. Its mineralogy was analyzed through X-ray diffraction (XRD), while scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM/EDS) and X-ray fluorescence (XRF) characterized its chemical composition, Macadamia nutshells were pyrolyzed at 700 °C for 45 minutes under an argon atmosphere to produce biochar, which was characterized using proximate and ultimate analysis. Reduction experiments were performed in an alumina tube furnace at 1300 °C under argon using a graphite crucible to assess the biochar’s effectiveness as a reductant. Preliminary results showed great that the use of macadamia biochar as an alternative reductant to produce high carbon ferromanganese production can be effective if thoroughly investigated. Also, the raw macadamia nutshell conversion to biochar was successful with fixed carbon reaching 85.97%.