Chemical analysis was performed and the phase composition of the sand dunes, which consists of quartz, clay minerals, carbonates and muscovite, was determined. The macrostructure of the proposed wall ceramics consists of sand pellets with a size of less than 1.5 mm and a finely ground bundle of sand and soda ash. Diagrams of the fusibility of sand dunes and composite bundles of finely ground sand dunes and soda ash are constructed. The affinity of the bundles to the grains of sand dunes and their high reactivity with respect to the surface of the grains ensures a high degree of sintering and obtaining low-stress ceramic structures. The physical and technical properties of sand pellets and firing bundles have been studied. Soda ash additives intensively increase the compressive strength of samples, as well as reduce water absorption and average density.The greatest increase in strength and reduction of water absorption, average density of samples is achieved with the addition of 3 % soda. The introduction of soda into the composition of mixtures contributes to the appearance of a liquid phase at low temperatures (740–760 °C), the amount of which increases with increasing temperature as a result, the sintering process intensifies, as a result of which the physical and mechanical properties of ceramics increase.The resulting liquid phase envelops the entire surface of the sand core, fills the voids between them and pulls the cores together, creating their most advantageous location. In addition, partially melting the surface of the sand core, the liquid phase of the shell contributes to an intensive increase in the amount of melt. The main crystalline phase is anorthite, the formation of which is possibly due to the reaction between CaO formed during the decomposition of calcite and metakaolinite formed during firing and quartz. A high-strength ceramic brick with a strength of 19.7 MPa and a water absorption of 15.4 % was obtained by semi-dry pressing and the content of sand in the charge of 97–99 %, soda ash 1–3 %.

ceramic brick, sand sand, soda ash, core, shell, semi-dry pressing, firing, physical and mechanical properties, strength, structure.