Abstract: Obtained from coal gangue as raw matcrials of boehmite was through mechanical activation, thermal activation and acid extraction.Mg-Al layered double metal hydroxides(LDHs) was produced by co-precipitation method.The products were characterized by XRD,IR and scanning electron microscopy (SEM) measurements.Experimental results show that: Coal gangue is activated at the calcination temperature of 700 ℃, leaching temperature is 100 ℃, extraction time is 150 min,the quality ratio between solvent and sample is 2∶10,the concentration of sulfuric acid is 4 mol/L,the ratio between liquid and solid is 15∶1,the extraction rate of Al2O3 is 0.937.When the molar ratio of Mg and Al is 2∶1,pH is 10 and the reaction temperature is 60 ℃,Mg-Al layered double hydroxides with interlamellar spacing d(003) of 0.798 nm are prepared by co-precipitation method.

Key words: coal gangue;boehmite;layered double metal hydroxides(LDHs);co-precipitation