Effects of chemical structure on the properties of carboxylate‐type copolymer dispersant for coal‐water slurry

Abstract

in Wiley InterScience (www.interscience.wiley.com).In this study, a series of carboxylate-type copolymer dispersants were prepared. The effects of chemical structures of the copolymer dispersants, including the molecular weight, kind, quantity and ratio of hydrophilic/hydrophobic groups, and side chain length, on the solid loading, apparent viscosity, zeta potential, rheological behavior, and stability of coal-water slurry (CWS) prepared from Dongtan, Yima, and Datong coals were systematically investigated. The dispersion performance of the copolymer can be improved by adjusting its chemical structures, and the dispersion mechanism was discussed. In addition, a high solid loading CWS with excellent stability toward settling can be achieved by means of the copolymer dispersant and carboxymethyl cellulose sodium salt (CMC-Na). Experiments have proved that the copolymer has the potential to be developed as a new high-effective dispersant for CWS. V

Production of carboxymethylated lignin and its application as a dispersant

“…The pKa of carboxylate group is 4.76 and below this pH, the carboxylate groups become protonated, which decreases its solubility [51]. Furthermore, the maximum solubility of carboxymethylated lignin was found to be 80 g/L at pH 7. repulsion between clay particles, and this increased the DC voltage and turbidity of the clay sample [52]. In a work conducted by Pawlik on coal aqueous slurries, anionic polymers were found to be better dispersants compared to non-ionic polymers because of their ability to generate electrostatic repulsion forces between the coal particles [53].…”

Influence of different dispersants on rheological behaviors of coal water slurry prepared from a low quality coal

“…In CWS preparation processes, dispersants could be employed to reduce the apparent viscosity of CWS by modifying the coal surface. 21,22 According to the charge properties of molecular chains, CWS dispersants included nonionic, anionic and cationic classes. Because of high cost and poor dispersion effect, cationic dispersants were rarely used in industry.…”

Coke Slurries with Improved Higher Heating Value and Good Processability via Particle Shape Design

“…Viscosity could be reduced using a certain amount of fine particle content. For further viscosity reduction, different surface‐active additives were used as dispersing or wetting agents, thus, an agglomeration of particles could be prevented and an increase of solids loading of the slurry could be achieved due to reduced attractive interactions among particles .…”