Investigation of the possibilities to modify the building ceramics by utilising MWCNTs

•MWCNTs+CMC modifying additive changes the microstructure of the semimanufacture.•0.0045% MWCNTs+CMC improves the properties of ceramic products.•Density of ceramic body (1000°C) increases by 4.7%, compressive strength – 32%.•MWCNTs additive has no influence on mineralogical composition of the ceramic bodies. Research deals with the possibility to improve the properties of ceramic products by utilising the modifying additive of multi-walled carbon nanotubes (MWCNTs), mixed with carboxymethylcellulose (CMC), which has the properties of dispersant, (MWCNTs+CMC). It was found that after the insertion of modifying additive (MWCNTs+CMC, sufficient to reach 0.0045 mass percent of MWCNTs in the overall formation mass) into ceramic products’ formation mass, plasticity as well as stability of the formation mass increase considerably and microstructure of semimanufacture changes. Density and strength of the semimanufactures become higher. Modified structure of the semimanufactures influences physical and mechanical properties of the burned ceramic bodies, as well as values of structure parameters. However, for the case when burning out sawdust additive is used in the composition of the formation mass, modifying additive has no noticeable influence on the properties of ceramic body. In this case, the absence of influence can be explained by considering that dry porous sawdust on the surfaces easier and more intensively absorb water dispersion with the particles of modifying additive, and therefore distribution of these particles in the formation mass is limited. Carbon nanotubes, adsorbed locally on sawdust particles, burn out together with sawdust. In such a way the positive influence of modifying additive is blocked. This interpretation was confirmed by the positive effect of modifying additive, when the other burning out additive–dispersed anthracite, which is distinguished by its hydrophobic properties, was introduced into the formation mass.