The thermodynamics of manganese oxide in high-MnO-containing slags was investigated using the chemical equilibrium method in the temperature range of 1623 to 1723 K. MnO-SiO₂-Al₂O₃ slags were brought into equilibrium with molten silver (Ag) under controlled CO/CO₂ gas atmosphere. The equilibrium Mn concentration in the silver was measured by ICP-AES (inductively coupled plasma atomic emission spectroscopy) analysis after the experiment. Slag samples were analyzed by EPMA (electron probe microanalyzer) analysis. The obtained activity a_MnO and activity coefficient γ_MnO were derived as a function of the slag composition and temperature. The activity coefficient of MnO within the investigated slag system increased with an increasing MnO/SiO₂ ratio. The derived temperature dependence of the activity coefficient and partition ratio of Mn between the metal and the slag was strongly influenced by the slag composition. The thermodynamic assessment of the activity and activity coefficient of MnO was carried out by applying the regular solution model (RSM) on the basis of interaction energies of the cations and with FactSage^TM 7.3. The theoretical calculations were compared with the experimentally derived values.

中文翻译：

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化学平衡法测定高锰渣中MnO活性系数的实验研究

使用化学平衡法在 1623 至 1723 K 的温度范围内研究了高 MnO 渣中锰氧化物的热力学。MnO-SiO ₂ -Al ₂ O ₃渣在受控的 CO/CO ₂气体气氛。实验后通过ICP-AES（电感耦合等离子体原子发射光谱）分析测量银中的平衡Mn浓度。通过EPMA（电子探针微量分析仪）分析来分析炉渣样品。得到的活度a _MnO和活度系数γ _MnO是作为炉渣成分和温度的函数推导出来的。随着MnO/SiO ₂比的增加，所研究的渣体系中MnO 的活性系数也增加。金属与渣之间的活度系数和分配比的衍生温度依赖性受渣组成的强烈影响。MnO 的活性和活性系数的热力学评估是通过基于阳离子的相互作用能和 FactSage ^TM 7.3应用常规溶液模型 (RSM) 进行的。理论计算与实验得出的值进行了比较。