【摘要】 以菱镁矿为初始原料，经煅烧、水化、碳化、热解获得棒状三水碳酸镁前驱体，并以三水碳酸镁和氯化铵（NH₄Cl）为原料，采用水热法制备无水碳酸镁晶体，探索水热温度、水热时间及固液质量比对产物物相组成和微观形貌的影响及形成机理。结果表明：NH₄Cl浓度为0.5 mol/L、水热温度为170℃、水热时间为11 h、固液质量比为1∶30时，可获得平均直径为2～5μm的菱块状无水碳酸镁晶体。水热反应期间，添加剂NH₄Cl水解产生的H⁺加速无水碳酸镁的形成。更多还原

【Abstract】 Using magnesite as the initial raw material, the rod-shaped nesquehonite precursor was obtained by a calcination-hydration-carbonization-pyrolysis method. Using nesquehonite and NH₄Cl as raw materials, anhydrous magnesium carbonate crystals were prepared by hydrothermal method. The effects of hydrothermal temperature, hydrothermal time and solid-to-liquid mass ratio on the physical phase composition and microscopic morphology of the products were explored, and the formation mechanism was further investigated. The results show that when the concentration of NH₄Cl is 0.5 mol/L, the hydrothermal temperature is 170 ℃, the hydrothermal time is 11 h and the solid-to-liquid ratio is 1∶30, rhombic anhydrous magnesium carbonate crystals with average diameters of 2～5 μm can be obtained. During the hydrothermal reaction, the H⁺ produced by ammonium chloride hydrolysis accelerate the formation of anhydrous magnesium carbonate.更多还原