Experimental Investigation of Coal Dust Wettability Based on Surface Contact Angle

Table 4

Determination results of contact angles of coal samples with different porosities.

Name of reagents	Contact angle/°
	Concentration/%	Coal samples from different work faces
		#10301	#1308	#7301
Sodium dodecyl sulfate (SDS)/anionic	0.005	16.73	19.43	26.35
	0.05	13.76	12.37	17.37
	0.5	0	0	0
Cetyltrimethyl ammonium bromide (CTAB)/cationic	0.005	12.78	14.34	19.25
	0.05	8.48	7.89	9.51
	0.5	0	0	0
Cocoanut fatty acid diethanolamide (CFAD)/nonionic	0.005	27.23	30.59	32.27
	0.05	17.87	18.65	20.92
	0.5	2.01	6.08	6.64
Dodecyl dimethyl betaine (DDB)/amphoteric	0.005	32.03	34.01	37.75
	0.05	23.41	25.11	25.81
	0.5	3.90	6.18	7.04