ABSTRACT
A D/MAX 2500 X-ray diffractometer (Rigaku, Japan) was used.
Rock samples were collected from different locations of the collapse columns and faults in the working surface of the Fenxi Shuguang coalmine (#1206). 200 g hand specimens, of a size of ∼15 cm, were taken for full-rock constituent analysis; whereas 50 g samples were taken from rock samples 1#, 2#, 3#, F14-1, and F14-2 for clay constituent analysis.
