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Samples of mechanically activated quartz sand powder were obtained by grinding on a planetary ball mill to different specific surface values (1200-3000 m2/kg). For these dispersed systems, the surface activity criterion (kS) was calculated as a value equal to the ratio of the free surface energy of the system to its total potential value (specific mass energy of atomization). It is established that the value of this criterion does not depend linearly on the time parameters of mechanical dispersion of the initial samples. The kS parameter is recommended for evaluating the effectiveness of the process of mechanical activation of rocks.

Rocks of various chemical and mineralogical composition are widely used as raw materials in the construction materials industry. At the same time, preliminary mechanical activation of mineral raw materials to a finely dispersed state contributes to a change in the energy potential of the system and affects the tendency of the surface of a finely dispersed system to transformations. Studies of the physicochemical activity of mechanically activated rocks allow to determine the rational areas of use of mineral components. The paper presents the results of evaluating the efficiency of mechanical activation of silica-containing raw materials by the values of surface activity (ks), defined as the ratio of the value of the free surface energy to the specific mass energy of atomization. Fine powders are obtained by grinding in a planetary ball mill to a different specific surface area of quartz sand (1200 – 3000 m2/kg) and polymineral sand (700 – 1335 m2/kg). The presence of a functional dependence of the surface activity on the time parameters of mechanical activation of the studied rocks is shown. The mechanical activation of the feedstock at the optimal time of its grinding makes it possible to achieve a given value of the surface activity. It is recommended to use the ks parameter as a criterion for assessing the efficiency of the process of mechanical activation of silica-containing rocks

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Introduction. Mineral raw materials, mechanically dispersed to a fine-grained condition, contribute to the effective use of the energy potential in the course of the structuring of composite materials. An important parameter, characterizing the dispersion ability and allowing to evaluate the ability of the system to transform is the specific surface of the substance. The experimental value of the specific surface depends on the measurement method and may differ for the same solids when different methods are applied. The purpose of the work is to study the morphological features of the surface of powdered quartz-containing systems having varying degrees of dispersion. The work represents the experimental identification of specific surface. Materials and methods. Filtration and adsorption methods were used to identify the specific surface of a mechanically activated sample of polymineral sand. Fine powders of sand were obtained by dry grinding in a planetary ball mill. The analysis of the obtained results was conducted taking into account the surface tension values of the powders as the characteristics of the surface energy of a surface area unit. Results. It is found that dimensions of the specific surface identified using the gas filtration method are smaller than those obtained using the nitrogen adsorption method. The authors have identified a linear functional dependence between the ratio of dispersion and polarization components of the surface tension and the ratio of specific surfaces obtained using different methods for one sample of sand. Conclusions. Despite a difference in the values obtained for the same material sample, specific surface area indicators, identified using different methods, allow to evaluate the extent of the surface maturity, the availability of active centres, and the energy potential of mineral powders. The ratio of specific surfaces can be used as a criterion for the rational choice of the operating parameters of mechanical activation of quartz-containing powder systems to increase the energy potential of the surface.