Leaching of aluminum from coal spoil by mechanothermal activation

Abstract

The process of activating coal spoil (CS) in order to recover aluminum as a high value product was investigated. The CS was first characterized by X-ray fluorescence (XRF), X-ray diffraction (XRD) and thermogravimetric analysis-differential scanning calorimetry (TGA-DSC) in order to determine the chemical and mineral compositions of the CS. Then a mechanothermal activation method was adopted to increase the aluminum activity in the coal spoil. Over 95% of the aluminum in the CS could be extracted using this activation method. The mechanothermal activation process promoted the destruction of kaolinite structures and hindered the formation of amorphous γ-Al₂O₃. This resulted in a high aluminum leaching activity in the mechanothermally activated CS.

Key words： coal spoil; mechanothermal compound activation; leaching

Acknowledgements

This work was financially supported by the National High Technology Research and Development Program of China (Grant No. 2011AA06A102), the National Natural Science Foundation of China (Grant No. 21306053), the Key Project of Scientific Research Innovation of Shanghai Municipal Education Commission (Grant No. 14ZZ063), and the Fundamental Research Fund for the Central Universities (WB1213008).

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