Abstract

The effects of dry grinding of diaspore (αAlOOH) on the structure of diaspore were investigated by means of X-ray diffraction(XRD), particle size measurement, infrared (IR)spectroscopy and nitrogen adsorption techniques. Grinding of diaspore can increase the BrunauerEmmetTeller surface area of diaspore. As the grinding time is prolonged, the rate of size reduction decreases gradually. The size reduction of the original diaspore particle appears to reach a limit after 2 h grinding. Particle size data suggest that moderate aggregation occurs during grinding. The mechanochemical effect obviously promotes the decreases in reflection intensities of XRD with the increase the grinding time, but no new phase appears between 1 h to 2 h grinding, and the structure of αAlOOH is still retained perfectly. N_2 adsorption study indicates that diaspore ground for 12 h shows a little smaller average pore diameter than the sample ground for 6 h and the original diaspore as well. This shows that the grinding is favorable for the formation of microstructure pores. IR spectroscopy analysis indicates that some change accurs in the bands of diaspore after mechanochemical treatment.