High-energy ball mill parameters used to obtain ultra-fine portland cement at laboratory level

One of the most significant characteristics of ultra-fine cement (UFC) is its high fineness (maximum particle size below 787 μin. [20 μm]). This kind of cement is obtained once ordinary portland cement (OPC) is ground in common grinding devices; the main disadvantages of this type of processing are the long time spent in milling processing and the high production cost. Some novel grinding devices, such as high-energy ball mills (HEBMs), have been used as an alternative to the fine and ultra-fine grinding process, especially in the advanced materials processing research field; but this is not often used in cement research. The aim of this research was to study the different milling parameters (time, ballpowder ratio [b/p], and milling speed) used in OPC dry-milling processing and to determine the most suitable combination of these parameters to obtain UFC at the laboratory level. This combination was determined after the characterization of the processed cement powder. The carried-out characterization techniques used were chemical composition, crystallographic phase quantification, change of temperature during the hydration process, and scanning electron microscopy (SEM) images for the morphology of the milled cement. The optimal combination of parameters produced an UFC with a maximum particle size below 590 μin. (15 μm) and a Blaine specific surface area (BSSA) of over 9000 cm²/g.