2026 Park Hydrogen DRI Melting Behavior

The iron and steel industry faces increasing pressure to reduce CO2 emissions, necessitating a shift from conventional fossil fuel reductants to hydrogen-based direct reduced iron (H2-DRI), which produces iron without direct carbon participation. This study investigates the melting behavior of H2-DRI under varying reduction degrees by blending with Coke Dry Quenching dust (CDQ) or Graphite (GR) and fluxing agents (CaO). Melting experiments were executed using in situ Confocal Scanning Laser Microscopy (CSLM) at temperatures up to 1585 °C under a purified Ar atmosphere. Our findings indicate that controlled carbon addition significantly lowers the melting temperature of H2-DRI, but only partial melting was observed, maintaining the porous structure. The acidic gangue components reacted with carbon to form stable oxides, preventing structural collapse, while CaO enhanced melting by neutralizing these components. Additionally, thermodynamic calculations identified optimal conditions for the rapid and complete melting of H2-DRI near 1400 °C, which is considerably lower than the melting point of pure Fe. These results demonstrate a feasible approach to reducing energy consumption in Electric Smelting Furnace operations through strategic carburization and flux addition, thereby promoting sustainable practices in iron and steelmaking.