Research Study of Zeta Potential and Wettability of Coal Slurries from Moravian-Silesian Region

Optimally functioning coal treatment plant circuit has a significant effect on the economic outcome of treatment of raw coal itself. Sludge is produced at the treatment plant by wet separation of fine particles. The main process, which involves the separation of coal particles from gangue grains, is the foam flotation. The effectiveness of the process depends on the mineral composition of the whole suspension. The main goal of the work was therefore focused on identification and evaluation of various physical and chemical (electrochemical) parameters in coal suspensions. Concern has been pointed on individual components of mixed coal slurries as well as on application of specific methods for the study of phase contact coal-water and three-phase contact of coal-water-air. Coal samples has been taken from active part of coal region of Mine Karvina CSA with technological granulation 0-0.5 mm. The results of the surface properties of the materials studies show a strong dependence of electrokinetic properties of samples of coal suspensions due to pH solutions and mineralized water. The study showed the zeta potential of the surface charge distribution of the samples at a pH. Relation between the mined raw coal and fine particles of coal material which is coming to coal treatment plant was characterized by zeta potential, contact angle and thermogravimetric analysis. Determination of wetting angle results of surface electrokinetic properties of real value added wettability with a visual assessment of the three-phase contact. Measurement results show sufficient wetting angle of the surface hydrophobicity of particles of coal samples with values between 70.14 degrees-77.24 degrees.