【摘要】 研究采用硫酸铵焙烧—水浸工艺提高菱镁矿的利用效率，结合XRD和TG-DTA分析以及对比硫酸铵焙烧MgO的物相变化得到焙烧过程中矿相的转化过程。实验结果表明，在菱镁矿粒度为～74μm、硫酸铵与菱镁矿物料摩尔比为1.6:1、焙烧温度为475℃和焙烧时间为2 h的条件下，镁的提取率达到98.7%。反应中物相转化过程可以概括如下：MgCO₃先转变为（NH₄）₂Mg₂（SO₄）₃，再分解得到MgSO₄。反应遵循化学反应和扩散混合控制机理，其表观活化能为33.02 k J/mol。更多还原

【Abstract】 (NH₄)₂SO₄ roasting–water leaching process was studied as a method for improving the utilization efficiency of magnesite. Transformation of the mineral phases during roasting was evaluated by X-ray diffraction（XRD） analysis, combined with thermogravimetry-differential thermal analysis（TG-DTA）. The data were compared with the phase transformation of Mg O during roasting using（NH₄）₂SO₄. The experimental results demonstrated that at a（NH₄）₂SO₄/magnesite（Mg O in ore） molar ratio of 1.6:1, roasting temperature of 475 °C, and roasting time of 2 h using a particle size of ～74 μm, the magnesium extraction rate reached a maximum of 98.7%. The phase transformation during roasting could be summarized as follows: Mg CO₃ was transformed into（NH₄）₂Mg₂（SO₄）₃, and then decomposed into MgSO₄. The reaction followed the mixed control mechanism involving chemical reaction control and diffusion control, with an apparent activation energy of 33.02 kJ/mol.更多还原