Effect of alkali earth oxides on the body of porcelain insulators

In porcelain insulator bodies, feldspar is generally used as a fluxing agent. Nowadays, studies on stoneware, ceramic sanitary ware, anorthite-based porcelains, bone porcelains, and ceramic tiles have observed the use of various magnesium oxide sources to provide fluxing properties, as well as an increase in strength values and a decrease of approximately 50°C in sintering peak temperatures. As an alternative to the high-cost feldspars used in porcelain insulators, the substitutability of raw materials containing alkaline earth elements will reduce raw material costs and create alternative fluxing sources. Additionally, by reducing the sintering times of porcelain insulators, it will help reduce natural gas consumption, conserving energy resources and enabling a more environmentally friendly production process. In this study, raw materials containing magnesium oxide, such as talc and magnesite, and raw materials containing calcium oxide, such as calcite and wollastonite, were substituted in the porcelain insulator body at 0.5-1% and 3% ratios, replacing potassium feldspar, and their effects on the technical properties were investigated. In electroporcelain, as the usage ratio of magnesium oxide sources like talc and magnesite, and calcium oxide sources like calcite and wollastonite increased, an increase in % apparent porosity, % water absorption, and deformation values, as well as a decrease in % apparent solid density, bisque and glazed firing strength values, were observed. Furthermore, as the proportion of these materials increased, it was found that calcium oxide sources reduced the % firing shrinkage in the porcelain insulator body, while magnesium oxide sources increased the % firing shrinkage.