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.　©　2021,　The　Minerals,　Metals　&　Materials　Society.