Low-temperature Sintering of High-Siliceous Clay under Conditions of Oxygen Deficiency

In the work, the processes of phase reconstruction and properties of ceramics obtained from high-siliceous clay-sand, clay-cullet, and clay-sand-cullet mixtures are considered. It is possible to perform plastic molding of blanks from the given mixtures due to the presence of montmorillonite in clay and sand and sintering at 800 oC for 8 h under conditions of oxygen deficiency. Depending on the composition of the initial mixtures, specimens ranging in color from gray to black can be obtained. It has been established by the XRD, IR spectroscopy, and electron microscopy methods that the synthesized material is glass ceramics consisting of quartz, feldspars, and a glass phase. Depending on the content of the initial components in the mixtures, it is possible to obtain glass ceramics with high strength properties or coarse-pored glass ceramics whose properties are similar to those of foamed ceramics.