Methane–Hydrogen-Based Pre-reduction Chromite: Reduction Behavior and Pellet Compressive Strength

This study has focused on reducing the carbon emissions and energy consumption for producing ferrochrome, an essential component in stainless-steel manufacturing. The research primarily investigates the reduction behavior and compressive strength of chromite pellets in atmospheres based on methane and hydrogen. The findings indicate that the reduction of pellets is positively influenced by temperature, time, and methane proportion. The most favorable reduction conditions were established with a methane concentration of 10% and a hydrogen concentration of 90% at 1100°C for a duration of 3 h, which achieved a comprehensive metallization rate of 36.3% for the pellets, with a strength of 1051 N. Additionally, the study has revealed that, with the decomposition of spinel, various chromium carbides initially formed, followed by the production of metallic chromium due to the highly reactive carbon released from methane cracking. The carbon filled the voids in the pellets, leading to densification of the surface layer. However, an excess of carbon can result in the pellets' outer layer becoming fragile and disintegrating. Therefore, the amount of methane input has been identified as a crucial factor affecting pellet strength, highlighting the need for a balanced methane input to effectively optimize pellet consolidation.