Evaluation of mechanical activation efficiency in construction-grade sands using various parameters

Industrial processes for the preliminary preparation of mineral raw materials, whether natural or man-made, often involve mechanical disintegration to achieve specific surface area values. This process is believed to activate the particles within the resulting powder systems, thereby enhancing the quality of the final building composites for various functional purposes. The outcome of mechanical activation is reflected in measurable changes in the energy characteristics of the surface of the analyzed system, such as the energy of the activated surface layer and the proportion of chemical bonds broken within it. Additionally, changes in the geometric shape of the surface particles are considered, particularly through the fractal dimension. To quantitatively assess the mechanical activation process, this paper presents a description of the changes in surface properties of highly dispersed powders produced by grinding sands from several deposits in the Arkhangelsk region. Based on experimental data, the following parameters were calculated for powders processed with varying grinding times: surface activity, the degree of change in properties, the proportion of broken bonds in the crystal structure, and the fractal dimension. The study found that despite a significant increase in the specific surface area and a decrease in the dimensional characteristics of the sand powders, the change in surface properties was only 6–7 % after 30 minutes of mechanical grinding, with volumetric property changes of up to 18 %. This indicates that activation processesoccur during the mechanical treatment of the studied raw materials.The research was funded by the Russian Science Foundation under project No. 23-13-20013, «Soil concretes using organomineral reactive binders for the reinforcement of historical road structures on the Solovetsky Archipelago».