PHOSPHATE CORUNDRUM CELLULAR CONCRETE WITH ALUMINOSILICATE INDUSTRIAL WASTE ADDED

Abstract

Phosphate non-fired materials are promising for use as heat-insulating materials. The paper presents the study results of the phase composition and structure of corundum cellular concrete with dispersed additives – fireclay production wastes and dialuminium trioxide with dichromium trioxide admixture. D800 concrete with a maximum application temperature of 1600 °C is obtained. Differential thermal analysis, X-ray phase analysis and electron microscopy methods are used in the study. The final phase composition is formed at a temperature close to the application temperature of 1600 °C and includes heat-resistant compounds such as corundum, aluminium orthophosphate in a cristobalite form, and magnesium spinel. The structure of the cellular concrete contains 3 mm pores, represented by complex aluminium phosphates (substituted aluminium phosphates). Aluminium orthophosphate forms in plate-like crystals. Heating cellular concrete to the application temperature does not significantly affect its structure. Cellular concrete with the fireclay production waste additives is found to have a denser structure compared to the composition with no additives. The paper describes the main heat-resistant properties of the developed cellular concrete. It shows that the addition of fireclay production wastes reduces the cost of cellular concrete and does not significantly affect its heat-resistant properties.