(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 650093)
摘 要: 對(duì)真空條件下碳熱還原氧化鋁進(jìn)行熱力學(xué)研究。結(jié)果表明：在1 643~1 843 K的溫度范圍內(nèi)，真空碳熱還原氧化鋁生成氣體產(chǎn)物，該氣體在溫度降低時(shí)發(fā)生二次反應(yīng)形成冷凝物，反應(yīng)過程中體系壓力保持在5~150 Pa。熱力學(xué)分析表明：當(dāng)體系壓力為1~100 Pa時(shí)，在1 200~1 900 K的溫度范圍內(nèi)，碳熱還原氧化鋁生成Al2O、Al和CO；生成Al2O的初始反應(yīng)溫度低于生成Al的初始反應(yīng)溫度，但反應(yīng)溫度高于一定值時(shí)，更易生成Al氣體，該溫度取決于體系的壓力；當(dāng)CO的分壓分別為1、10和100 Pa時(shí)，Al2O穩(wěn)定存在的溫度分別高于1 462、1 560和1 674 K，Al氣體穩(wěn)定存在的溫度分別高于1 514、1 635和1 777 K。
關(guān)鍵字: 氧化鋁；碳；碳熱還原；熱力學(xué)
（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 650093, China）
Abstract:The thermodynamics of the carbothermal reduction of alumina in the vacuum was investigated. The experimental results show that the reduction of alumina with carbon generates gaseous products at a temperature ranging from 1 643 to 1 843 K, and then the gaseous products react to form condensates at lower temperatures, in which the pressure is ranged from 5 to 150 Pa. Thermodynamic analysis indicates that the carbothermal reduction of alumina leads to the generation of Al2O, Al and CO gas at a temperature ranging from 1 200 to 1 900 K and a pressure ranging from 5 to 100 Pa. The initial temperature of the formation of Al2O is lower than that of the formation of Al. However, the formation of Al is easier than that of Al2O when the reaction temperature is higher than a certain value that is determined by the pressure of the system. When the pressure of CO is 1, 10 and 100 Pa, Al2O is stable above 1 462, 1 560 and 1 674 K, and Al is stable above 1 514, 1 635 and 1 777 K, respectively.
Key words: alumina; carbon; carbothermal reduction; thermodynamics
