(1. 福州大學石油化工學院，福州 350108；
2. 澳大利亞科廷大學西澳礦業(yè)學院，西澳大利亞 6102)
摘 要: 針對當前由粉煤灰制備氧化鋁成本高、除雜難度大等問題，提出了以富鋁粉煤灰為原料的硫酸加壓浸取、鉀明礬結晶凈化、鉀明礬熱解生產氧化鋁的新技術路線，并對關鍵環(huán)節(jié)進行了熱力學分析和試驗驗證。結果表明：該技術路線可實現低物料消耗、低能耗浸出，高效地解決從復雜硫酸鹽溶液中分離鋁的問題，并實現了反應過程所需硫酸、硫酸鉀以及過量硫酸的循環(huán)利用。通過與傳統(tǒng)拜耳法生產氧化鋁工藝對比，本文所述技術路線理論能耗和物料消耗更低、原料來源更廣泛，展現了高硅富鋁粉煤灰酸法生產氧化鋁新工藝的廣闊應用前景。
關鍵字: 粉煤灰；酸法；鉀明礬；熱解；氧化鋁
（1. College of Chemical Engineering, Fuzhou University, Fuzhou 350116, China;
2.Western Australian School of Mines: Minerals, Energy and Chemical Engineering, Curtin University, WA, 6102, Australia）
Abstract:Theproduction of aluminium oxide from coal flay ash, an aluminum-rich and silicate-based solid waste, has been found uneconomic, particularly due to the great challenge for impurity removal.The present study proposes a new process to recover aluminum oxide from coal fly ash using pressure leaching with sulfuric acid, followed by crystallization and pyrolysis of potassium-alum. The thermodynamic and experimental analyses results show the feasibility of obtaining metallurgical-grade aluminum oxide using the new process, with low reagent and energy consumption. In the process, the separation of aluminum from the complicated sulfate leachate can be achieved efficiently. The excess sulfuric acid, potassium sulfate and oxy-sulfide (obtained from pyrolysis) can all be recycled for reused. The comparisons between the new process and the traditional Bayer process indicate that the new process for aluminum oxide production from aluminum-rich and silicate-based materials has a wide application.
Key words: coal fly ash; acidic method; potassium alum; pyrolysis; aluminum oxide
