(1. 昆明理工大學(xué) 冶金與能源工程學(xué)院 真空冶金國家工程實(shí)驗(yàn)室，昆明 650093；
2. 昆明理工大學(xué) 理學(xué)院，昆明 650500)
摘 要: 通過熱力學(xué)分析和實(shí)驗(yàn)研究了真空條件下碳熱還原氧化鋁的二次反應(yīng)。熱力學(xué)分析表明：低溫、高壓有利于碳熱還原氧化鋁的產(chǎn)物Al2O、Al與CO的二次反應(yīng)。分別繪制了Al2O和Al在一定分壓下，與CO的二次反應(yīng)平衡曲線圖，給出了各二次反應(yīng)的CO平衡分壓與溫度的關(guān)系，根據(jù)CO的分壓和溫度、利用二次反應(yīng)平衡曲線圖分析二次反應(yīng)的產(chǎn)物。氧化鋁與石墨的真空碳熱還原實(shí)驗(yàn)研究證實(shí)：Al2O與CO降低溫度首先生成Al4O4C和C，Al與CO降低溫度首先生成Al4O4C和Al4C3，符合根據(jù)二次反應(yīng)平衡曲線圖分析得到的結(jié)論，說明二次反應(yīng)平衡曲線圖的合理性。
關(guān)鍵字: 碳熱還原；氧化鋁；石墨；真空；Al2O；Al
（1. National Engineering Laboratory of Vacuum Metallurgy, Faculty of Metallurgy and Energy Engineering,
Kunming University of Science and Technology, Kunming 650093, China;
2. Faculty of Science, Kunming University of Science and Technology, Kunming 650500, China）
Abstract:The back-reactions of the carbothermal reduction of alumina in a vacuum were investigated. The thermodynamic analysis indicates that both low temperature and high pressure favor the back-reactions of Al2O3, Al and CO generated from the carbothermal reduction of alumina. The equilibrium curves for the back-reactions of Al2O and CO, and those of Al and CO are obtained, respectively, for certain partial pressures of Al2O and those of Al, showing the CO equilibrium partial pressure of the back-reactions as a function of the temperature. From the equilibrium curves, the species formed by the back-reactions are determined by the CO partial pressure and the temperature. The experiments on the alumina and graphite show that Al2O reacts back with CO to first form Al4O4C and C, and Al reacts back with CO to first form Al4O4Cand Al4C3, verifying the conclusions obtained from the equilibrium curves. The equilibrium curves of the back-reactions are reasonable.
Key words: carbothermal reduction; alumina; graphite; vacuum; Al2O; Al
