Interaction between quaternary ammonium surfactants with coal pitch and analysis surfactants effects on preparing coal pitch water slurry

•The wetting of the OTAC, CTAC and HDBAC aqueous solution the surface of coal pitch obeys Zisman theory.•The value of adhesion work of the OTAC, CTAC and HDBAC aqueous solution on the surface of coal pitch is basically the same.•The mass concentration of coal pitch water slurry preparing by OTAC can reaches 62–67% and shows a pseudo-plastic behavior.

The wetting behavior, adsorption amount and Zeta potential of aqueous solutions of the octadearyl dimethyl ammonium chloride (OTAC), cetyl trimethyl ammonium chloride (CTAC) and benzyl hexadecyl dimethyl ammonium chloride (HDBAC) on coal pitch surface were investigated. When the content of surfactant was constant, along with the growing of slurry concentration, the apparent viscosity of coal pitch water slurry (CPWS) increased. On the other side, it declined when shear rate grew. There was a liner relationship between contact angle and surface tension, so Zisman theory was well agreed with this wetting system. The adsorption amount of dispersants on coal pitch surface increased with the growing of solution concentration. The Zeta potential grew at first, and then stayed the constant.

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