Research Article

Effects of Oxygen Element and Oxygen-Containing Functional Groups on Surface Wettability of Coal Dust with Various Metamorphic Degrees Based on XPS Experiment

Figure 1

Chart of XPS full spectrum scan of coal samples with different metamorphic grades.
(a) Beizao lignite
(b) Yushuwan gas coal
(c) Xinjulong fat coal
(d) Yangquan anthracite