(1. 云南師范大學 化學化工學院，昆明 650092；
2. 昆明理工大學 真空冶金國家工程實驗室，昆明 650093)
摘 要:
利用“物質(zhì)吉布斯自由焓函數(shù)法”，討論不同壓力下低價氟化鋁生成及分解的熱力學條件。結(jié)果表明：系統(tǒng)壓力為100 kPa時，在1941.76 K以上才能生成低價氟化鋁；而當系統(tǒng)壓力降低到100~10 Pa時，在1 486.32~ 1 373.28 K 能生成低價氟化鋁。同時，當系統(tǒng)壓力小于300 Pa時在1 673 K下用氧化鋁、氟化鋁與還原劑碳在真空爐內(nèi)實驗，驗證了理論研究結(jié)果，得到純度為93.77%的金屬鋁；以焦碳作還原劑，鋁土礦為原料在1 723 K進行了實驗，得到純度為95.13%的金屬鋁。
關鍵字: 鋁；真空冶金；歧化反應；低價氟化物；制備
（1. School of Chemistry and Chemical Engineering ,Yunnan Normal University, Kunming 650092, China;
2. National Engineering Laboratory of Vacuum Metallurgy, Kunming University of Science and Technology,Kunming 650093, China）
Abstract:Thermodynamics process and experiment of aluminum extracting from bauxite and Al2O3, were studied. The temperature, at which alumina, aluminum fluoride and carbon react to form aluminum sub-fluoride at different pressures, was evaluated with “Substance Gibbs’ Free Energy Functional Determinant” method. The results show that the reaction temperature can be considerable declined in vacuum, such as the temperature dropped to 1 486.32−1 373.28 K in the pressure range from 100 Pa to 10 Pa, but the temperature of the reaction needed is more than 1 941.76 K under 100 kPa. The metal aluminum with the purity of 93.77% is obtained by the experiment alumina, aluminum fluoride and carbon in a vacuum furnace when the system pressure is less than 300 Pa at 1 673 K; the aluminum metal with the purity of 95.13% is also gotten at 1 723 K by using coke for reducing bauxite.
Key words: aluminum; vacuum metallurgy; disproportion; sub-fluoride; preparation
