Magnesium oxide

Patent Granted The invention relates to the technical field of comprehensive utilization of secondary resources, in particular relates to a method for preparing high-purity magnesium oxide from titanium sponge byproduct fused magnesium chloride. The method comprises the following steps: in the process of titanium sponge production, leading the fused magnesium chloride generated in a distillation process section and oxygen into an in-situ pyrolytic reaction device in a molar ratio of (1:0.5)-(1:10); and carrying out pyrolytic reaction for 1-60 minutes by utilizing waste heat of the fused magnesium chloride while stirring at the reaction temperature of 600-1000 DEG C so as to obtain a solid product containing magnesium oxide and a byproduct chlorine.