Coal fly ash, commonly produced from thermal power plants, is not only an industrial waste but an aluminum-rich resource that needs to be disposed of properly. This study aims to extract aluminum from coal fly ash using pressurized sulfuric acid (H₂SO₄) leaching and to investigate the dissolution mechanism during the leaching process. The effects of initial concentration of H₂SO₄, reaction temperature and time on the extraction of aluminum were investigated. Under optimized conditions (3 mol/l H₂SO₄, 220°C and 180 min), the extraction of aluminum reached 82.51%. It was found that mullite (3Al₂O₃·2SiO₂) contained in coal fly ash was completely dissolved during the leaching, while the dissolution of silica-alumina glass beads was at a limited degree. The un-leached aluminum was found to be locked inside the glass beads which H₂SO₄ was unable to access.

通常由火力发电厂产生的粉煤灰不仅是一种工业废物，而且是一种需要妥善处理的富含铝的资源。本研究旨在使用加压硫酸 (H ₂ SO ₄ ) 浸出从粉煤灰中提取铝，并研究浸出过程中的溶解机制。考察了H ₂ SO ₄初始浓度、反应温度和时间对铝提取的影响。在优化条件下（3 mol/l H ₂ SO ₄、220℃、180 min），铝的提取率达到82.51%。发现莫来石(3Al ₂ O ₃ ·2SiO ₂) 粉煤灰在浸出过程中完全溶解，而硅铝玻璃珠的溶解程度有限。发现未浸出的铝被锁定在 H ₂ SO ₄无法进入的玻璃珠内。