Research on the magnesium reduction process by integrated calcination in vacuum

Abstract At present, the predominant method for magnesium production relies on the Pidgeon process, a straightforward yet inefficient procedure characterized by high energy consumption and substantial greenhouse gas emissions. In order to foster advancements in magnesium production technology, this study explored an approach that consolidates silicon calcination and thermal reduction stages into a single stage. The main raw material used in this process is dolomite powder, which replaces the previously calcined dolomite. The primary objective of this novel approach is to streamline production timelines, enhance coherence between stages, and curtail energy usage in magnesium production. The investigation delves into the impact of dolomite decomposition temperature and forming pressure on the efficiency of the integrated process. Laboratory-scale experimentation revealed that the optimal decomposition temperature is 800°C. While the forming pressure significantly influenced the reduction rate, it did not markedly impact the final reduction efficiency. A forming pressure of 150 MPa yielded the highest reduction rate. This decrease is attributed to the dissociation of reactants during dolomite decomposition, indicating a need for further research to address the reduction in contact area during the degradation stage and enhance the efficiency of this integrated process.