Devolatilization of charcoal and interaction of volatiles with manganese ore

Charcoal is considered as an alternative reductant in manganese ferroalloy production to replace metallurgical coke, thereby reducing fossil-based CO₂ emissions. However, charcoal differs from metallurgical coke in both chemical and physical properties. Its higher CO₂ reactivity may lead to increased carbon and energy losses via the Boudouard reaction. Additionally, its lower mechanical strength can result in excessive fines within the furnace, negatively affecting permeability. Charcoal also contains a higher proportion of volatile compounds compared to coke. Previous studies have shown that gases such as hydrogen, carbon monoxide, carbon dioxide, and methane are released from charcoal when temperatures reach 400–500 °C. Increased volatiles content may introduce challenges in the off-gas handling due to increased gas-flow. On the other hand, if these volatile species interact with manganese ores in the furnace, they may enhance the prereduction process, potentially lowering the specific carbon and energy consumption during production. In this study, the devolatilization behaviour of industrial charcoal and the effect of its volatile species on the prereduction of manganese ores were investigated.