The paper studies the influence of nanodispersed aluminum and silicon oxides on the structural, physico-chemical and mechanical characteristics of calcium-magnesium bentonite deposits of the Republic of Tatarstan, in order to determine the optimal concentrations of the nanomodifier, and to improve the performance of respective materials. It was found that nanomodification of bentonite increases the strength of samples after firing by more than 1,5 times, the adsorption index by 20–25 %. The optimal concentration of nanoparticles was determined by changing the properties. The methods of Brunauer-Emmett-Teller (BET), x-ray phase analysis and infrared spectroscopy show an increase in the specific surface area, a change in the phase composition of the annealed samples, the intensity and position of the characteristic absorption bands, as well as the chemical bond silicon-oxygen in bentonite, modified by nanoparticles of aluminum and silicon oxides of similar nature.

The paper shows the possibility of using such quantitative characteristics of the element-oxygen chemical bond as the covalent character, metallic character and ionic character in substances to select a set of technological methods and develop a technology for nanomodification of natural bentonite aluminosilicates. The research results showed that thermal activation of bentonite at 200, 300, 380 and 400 °C with different modes of isothermal exposure (15, 30, 60, 120 minutes) does not significantly affect the efficiency of its modification with silicon (SS) and aluminum (AS) oxide nanoparticles, estimated by the increment of the compressive strength and the adsorption index for methylene blue. Obtaining a 46 % aqueous suspension of bentonite and modifying it with silicon and aluminum oxide nanoparticles followed by ultrasonic treatment after standing decreases the particle size by more than 4 times, which is a promising technological solution for improving the performance properties of ceramics, molding mixtures, adsorbents and other materials based on bentonite from various deposits.

The paper considers the formulation of nanomodification of alumino-silicate raw materials, in order to obtain ceramic materials, based on it, by various molding methods with an increased strength and other operational properties. Studies of the dependence of the compressive strength on the type and concentration of aluminum and silicon oxide nanoparticles, their influence on the granulo-metric composition and microstructure of alumino-silicate powders, based on alkaline earth bentonite, are presented. It is shown that the addition of oxide nanoparticles in small concentrations leads to a decrease in the average particle size, aggregated structural elements of bentonite and their redistribution, and changes in morphological parameters (the shape of micro-aggregates and aggregates, pores), which increases the strength of raw materials and, as a result, burnt products.

The article studies the chemical, mineralogical, granulometric composition and type of chemical bond, as well as meso- and macrostructure of bentonite of the Nurlat deposit of the Republic of Tatarstan. By laser diffraction, the average particle size in the studied bentonite was found to be dominated by fractions of particles with a size of less than 10 µm (31.18%) and 10-40 µm (36.99%). The average particle size of bentonite was 45.67 µm. According to X-ray analysis, bentonite is mineralogically represented by montmorillonite with an interplane distance of 15.0 Å (001), muscovite, chlorite, kaolinite, clinoptilolite, albite and quartz. The microstructure of bentonite is formed mainly by large anisometric flattened microaggregates and volumetric isometric aggregates up to 70 µm. The average pore size was 0.23 µm, porosity was 39.2%. The microstructural model was cellular with elements of a spongy structure.

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