Separation of Mg and Si from low-grade magnesite through sulfuric acid leaching method

Sulfuric acid leaching method was used to separate magnesium and silicon from low-grade magnesite directly in this paper. The studies indicate that when the reaction time is 2 h, reaction temperature 150°C, mixture ratio of acid and magnesite 3:1 (ml:g), acid concentration 70%, the extraction rate of Mg is 96.2%. The acid-leaching residue was detected by XRD and SEM. The main component of residue is SiO₂, minute quantity talc phase exists. The residue is cellular, the framework of magnesite particles isn´t destroyed.