Steam Calcination of Magnesite for the Production of Reactive Magnesia

This study systematically evaluates steam calcination as a method for producing magnesium oxide (MgO) from magnesite (MgCO₃), by testing actual industry samples under varying conditions. While the potential benefits of steam calcination were previously acknowledged, this work provides the first comprehensive quantification of its advantages over conventional methods such as flue gas and flue gas with steam calcination. The results demonstrate that steam calcination significantly lowers the decomposition temperature of MgCO₃, achieving near-complete decomposition within 20 min at 600°C while also accelerating the decomposition of dolomite and calcite present in magnesite ores. Steam calcination enhances the specific surface area of MgO to 49.61 m²/g, optimizes structural properties such as pore volume, and improves reactivity, with reaction times as short as 45 s. Environmentally, steam calcination reduces total energy consumption by approximately 15%, and simplifies CO₂ capture by separating it from condensed steam, enabling a potential carbon emissions reduction of 1.09 kg CO₂-e per kilogram of MgO produced. Furthermore, its compatibility with renewable energy sources aligns with sustainable industrial goals, establishing steam calcination as a highly efficient and environmentally friendly alternative for industrial MgO production.