Preparation method for producing macrocrystalline fused magnesite and co-producing fused magnesite and light calcined magnesia by one-step method

The invention relates to the technical field of fused magnesite production, in particular to a preparation method for producing macrocrystalline fused magnesite and co-producing fused magnesite and light calcined magnesia through a one-step method. The preparation method comprises the following steps: selecting magnesite which has the magnesium oxide content of more than 45wt% and is ground to the granularity of 30-80mm as a raw material; smelting in an electric arc furnace: adding the magnesite raw material into a closed double-body electric smelting magnesium smelting furnace, and continuously electrifying and smelting for 7-10 hours at the temperature of 3000-3500 DEG C; and after smelting is finished, a hot air circulation temperature control system of the closed double-body fused magnesia smelting furnace is started, heat preservation cooling crystallization, graded crushing and screening are carried out, and large-crystal fused magnesia, fused magnesia and light calcined magnesia are obtained. According