Dispersion performances and adsorption behavior of novel block polycarboxylate with hybrid side chains in coal-water slurry

Abstract

A serial of novel block polycarboxylate dispersants (PCDs) with hybrid side chains employing long-short composite side chains for making coal-water slurry (CWS) were synthesized and applied to a low rank coal in the north of China to make slurry. The relationship of the fine structure of side chains and properties of the CWS were investigated. The results show that the apparent viscosity, zeta potential and stability of the CWS are impacted by the molar ratio of short side chain to long side chain of the PCD. Meanwhile, the viscosity reduction, stability property and zeta potentials of the CWSs are increased in accord with the order of adsorption amount of PCD on coal. These facts confirm that the PCD with a molar ratio of the short side chain to long side chain of just over unity more easily forms a larger adsorption amount on the coal surface and has optimal dispersion and stability characteristics. It is helpful to regulate the adsorption behavior of polycarboxylate dispersant to improve its dispersion property. It provides a good pathway to design and prepare a highly effective dispersant for low rank coal.