Study on the particle morphology, powder characteristics and hydration activity of blast furnace slag prepared by different grinding methods

This paper compares and studies the particle morphology, particle size distribution (PSD) characteristics, powder characteristics and hydration characteristics of ground granulated blast furnace slag prepared by a ball mill and a vertical roller mill. Both types of slag particles are found to comply with the Rosin-Rammler-Bennett (RRB) distribution model. The degree of sphericity of the blast furnace slag powder particles decreases with the particle size and is lower when produced by vertical roller milling than by ball milling; the differences in particle morphology mainly exist at the 0-3 mu m particle grade. For the same specific surface area, ball-milled slag powder has a higher angle of repose, natural bulk density and tapped bulk density than does vertical-roller-milled slag powder. Both slag powders are categorized as Coulomb solids, which exhibit cohesiveness and high flow resistance. Ball-milled slag powder has better hydration activity than that of vertical-roller-milled slag powder. The difference in the homogeneity coefficients of the two powders is important to the obvious differences in the particle characteristics and hydration activities of the ball-milled and vertical-roller-milled slags. (C) 2020 Elsevier Ltd. All rights reserved.