A contribution to the mechanism of formation of humic acids in coal

This paper presents a study of the influence of mechanochemical activation of coal on the process of formation and degradation of humic acids. The increasing period of mechanical activation of coal causes an increase in hydrophility, electrophoretic mobility, and of electrokinetic potential of surface layers as a result of acidic carboxyl and phenolic OH groups. The effective activation requires a short period of grinding. The increased time of activation causes the secondary processes of grain agglomeration and degradation of humic acids.