中国是世界上最大的金属镁生产国和出口国，但较低的镁还原率导致炼镁能耗高、生产效率低、废镁渣多且氧化镁含量高，严重制约了中国金属镁产业的绿色、健康发展。为提高炼镁还原率，对炼镁原料煅白进行了改性处理。首先，将白云石煅烧得到的煅白通过水化-再煅烧工艺制备水化改性煅白。随后，分别以煅白和水化改性煅白为原料，与硅铁、萤石混合并压制成还原球团，在高温、真空条件下进行炼镁实验。通过热重分析（TG）、X射线衍射（XRD）、比表面积分析（BET）、粒度分析仪及扫描电镜-能谱分析（SEM-EDS）对水化改性前后煅白及炼镁实验还原渣的物相性质、结构、组分和形貌进行了系统表征。实验结果表明，水化改性后的煅白粒度显著减小，颗粒尺寸从60 μm降至1 μm，其微观形貌呈现疏松多孔结构，孔隙发达且孔径增大，比表面积从8.41 m²/g增加至23.23 m²/g。煅白经改性处理后，炼镁实验的镁还原率显著提高，在还原时间为1.0 h的条件下，以煅白为原料的炼镁实验镁还原率为82%，而以水化改性煅白为原料的炼镁实验镁还原率提升至94%。这表明水化改性处理有效改善了煅白的物理化学性质，从而显著提升了炼镁效率。

China is the world′s leading producer and exporter of metallic magnesium.However，the low reduction rate of magnesium oxide results in high energy consumption，inefficient production，and a significant amount of waste magnesium slag with a high content of magnesium oxide.This hinders the green and healthy development of the metallic magnesium industry.To enhance reduction rate of magnesium oxide in magnesium smelting，modified treatment was conductedon the dolime.The dolime derived from dolomite was firstly hydrated and subsequently subjected to further calcination in order to produce hydrated modified dolime.Then the dolime and the hydrated modified dolime were mixed with ferrosilicon and fluorite，pressed into reduced pellets，and subjected to the magnesium extraction experiment under high temperature and vacuum.The properties，structure，composition and morphology of dolime before and after hydration modification and the residual slag and Mg after experiments were characterized by TG，XRD，BET，particle size analyzer and SEM-EDS.The results demonstrated a significant reduction in the particle size of hydrated modified dolime，with the particle size decreasing from 60 μm to 1 μm.The microstructure exhibited a loose and porous nature，characterized by well⁃developed pores and increased pore size，and the specific surface area was increased from 8.41 m²/g to 23.23 m²/g.Furthermore，the modification treatment led to an increase in the reduction rate of magnesium oxide，as evidenced by a reduction rate of 82% for magnesium oxide in experiments using dolime as raw material under a reduction time of 1.0 h，compared to a reduction rate of 94% for magnesium oxide in experiments using hydrated modified dolime as raw material.It suggested that the hydration modification treatment effectively enhanced the physicochemical properties of the dolime，thereby significantly boosting the magnesium smelting efficiency.