Abstract
Abstract The paper presents the results of researching magnesia compositions, which contain caustic magnesite and porous technogenic fillers. The research is aimed at creating resource-saving magnesia materials with the density less than 1000 kg/m3. The dependence of the magnesia composition’s density and strength on the size of arboreal particles is exposed. The increase of the particles’ size lowers the density of materials, but worsens the moulding characteristics. The influence of ash microsphere on the structural and mechanical properties of magnesia materials is found out. The content of hollow particles in the magnesia mixture is restricted due to the decrease of the raw materials’ mass plasticity. The mathematical models, presenting the dependences of moulding mass’ properties and composition density on the filler’s composition, are obtained. The compositions of raw materials’ mixtures for getting materials with a reduced density are determined. Moulding masses, which contain the integral filler (20-50% of arboreal particles with the size 0.63-2.5 mm and 50-80% of the ash microsphere), are preferable. The combination of fibrous and spherical hollow particles provides mouldability of the raw materials’ mixture as well as a reduced density of magnesia compositions. The electronic microscopy is used to research the materials’ structure.