Energy model of surface activation of mineral components of building composite materials

To evaluate effectiveness of mechanical activation of mineral powder applied as a mineral additive for building materials structure formation control it is proposed to use two characteristics: the ratio of coefficients ka/ks and the surface fractal dimension Ds. Proposed mathematical algorithm allows us to characterize dispersed systems by changes in the energy properties of a surface of particles directly involved in the process, and to calculate the fractal dimension of the surface formed with grinding. The adequacy of the proposed model was tested on highly dispersed powders of quartz sand and saponite-containing material isolated from a recycled water suspension of kimberlite ores processing. It is shown that for the studied systems raw materials the 30-minute duration of mechanical dispersion process on a planetary ball mill leads to a significant change of the substance surface properties, and the fractal dimension was 2.36 for quartz sand and 2.46 for saponite-containing material. It is also shown that the traditionally used criteria for evaluating effectiveness of raw materials mechanical grinding on parameters specific surface area and particle size parameters are important, but insufficient. The developed model of mechanical activation, which uses treated substance various constants, establishes the relationship not only between the total number of bonds broken during processing and the number of bonds that change surface properties (the ratio of coefficients ka/ks), but also takes into account changes in the surface geometric characteristics.