Table 1.
The 12 kinds of surfactants selected in the experiment.
Fig 1.
Diagram of the experimental equipment.
Fig 2.
Sedimentation experimental device.
Fig 3.
Ultimate analysis and proximate analysis of lignite.
Table 2.
Absorption peaks of groups.
Fig 4.
Infrared spectrogram of lignite.
Fig 5.
Surface tension of surfactants at different concentrations;(a) Anionic surfactants, (b) Nonionic surfactants, (c) Amphoteric surfactants.
Fig 6.
Contact angle between solid and liquid.
Fig 7.
Contact angle of surfactants at different concentrations;(a) Anionic surfactants, (b) Nonionic surfactants, (c) Amphoteric surfactants.
Table 3.
Sedimentation velocity of surfactants at different concentrations.
Fig 8.
The wetting feature of compound solutions.