Zeta potential of coal fine-particles in aqueous suspension

The relation between the zeta potential of coal fine-particles and pH value of suspension in aqueous suspension for different kinds of coal samples was determined by using a rectangular micro-electrophoresis cell.

The empirical equation of the relation between the zeta potential of the particles and the chemical components of coal samples was determined in aqueous suspension of different pH values. The equation is represented as follows: Z = B_C × (C) + B_H × (H) + B_O × (O) + B_N X × (N) + B_S × (S) + B_A × (A) where Z is the zeta potential of the particles, (C), (H), (O), (N), (S) and (Ash) are weight percent of carbon, hydrogen, oxygen, nitrogen, sulphur and ash, respectively, and B_C, B_H, B_O, B_N, B_S and B_A are coefficients of each of the respective components of coal samples.

The above coefficients were calculated numerically by the least-square method in suspensions with different pH values. The values of the coefficients, B_C, B_H, etc., (mV/%), indicate the zeta potential of each respective single component; viz. carbon, hydrogen, etc., of the coal samples. When the chemical components of a coal sample are known, the zeta potential of the coal fine-particles can be determined by the equation with the coefficients obtained in suspensions with different pH values.