Abstract: The raw coal waste is very stable and difficult to extract Al₂O₃ directly without chemical activation. In the current work, with mechanical ball milling of the coal waste for 10h, the Al₂O₃ extraction ratio is improved from 7.24 % to 88.17 % and the reactivity of waste can be efficiently enhanced by ball milling; even for the waste after calcinations, the milling method is still effective and with increase of the milling time, the effect of activation is more marked.