Features of mullite synthesis in fireclays on addition of natural topaz components

In the work presented the influence of topaz components on the process of mullite formation was considered. The mullite determines the basic properties of ceramic materials of the silica-alumina nature. Not only common mullite content in a structure of ceramics, but also its structural - morphological features are of the significant value. As a clay component, a non-plastic refractory clay was used, which is widely applied in technologies of both fine ceramics such porcelain and faience and in technologies of silica-alumina refractories. However, under conditions of special preparation it can act as a binding agent. Here it was established, that the influence of topaz rock additions depends on their mineralogical compositions, namely, the relation between topaz and quartz. The data concerning moderating action of increased quartz content on the process of mullite synthesis in kaolinite clays were confirmed. The nature of topaz influence on physico -chemical processes in fireclay is determined by its quantity. Topaz in small quantities (up to 0,5-1,0 %) intensifies the process of mullite and cristobalite formation. It is accompanied both by decreasing their synthesis temperature by 50°C, and increasing an output and improvement of the mullite structure.