Studies on the Properties of Modified Sulfonated Acetone Formaldehyde Polycondensate as a Dispersant for Coal–Water Slurry

As a dispersant for coal–water slurry (CWS), sulfonated acetone formaldehyde condensate dispersant (SAF) has advantages in synthesis process, cost, and performance, but its application in the industrial production of CWS is constrained due to its weak adsorption affinity with the coal surface, especially as the desorption phenomenon becomes more pronounced with increasing temperature. In this paper, the modification of SAF was conducted to achieve effective adsorption on the coal surface and a wider temperature adaptation range. The molecular structure of the modified SAF (MSAF) was characterized using Fourier transform infrared (FT-IR) spectroscopy, and the interface characteristics of coal/water were studied through measurements of contact angle, adsorption of dispersants, and ζ-potential. Additionally, the effect of temperature changes on the properties of CWS prepared with different dispersants was investigated. The results indicated that compared with the CWSs prepared from dispersants SAF and NSF (napthalenesulfonate formaldehyde condensate), the CWS prepared from dispersant MSAF had pseudoplasticity, higher concentration, better fluidity, and superior stability and could be suitable for a wide temperature range. Correspondingly, the action mechanisms of MSAF as a high-performance dispersant for CWS were elucidated. The studies expand the application of SAF-based dispersants in the field of CWS, providing a demonstration of the modification of CWS dispersants.