high inclined angle coal seam
coal seam with high gas content and low permeabili
coal seam with greater inclination angle
coal with high ash fusion temperature
Deeply Inclined Coal Seam
fat coal with high sulfur content
shallow coal seam with thin bedrock
sharply inclined coal seam
steep-inclined coal seam
Steeply Inclined Coal Seam
top coal seam with parting band
deep inclined seam with potential outburst
deeply inclined angle seam
high inclined angle large section
abnormal coal seam thickness