High Mechanical Strength Porcelain Body Prepared from Amakusa Pottery Stone Containing Soda Feldspar

Abstract

Amakusa low refractory potterystone contains a certain amounts of soda feldspar, so have not been used as raw materials of porcelain body. Effects of grinding on manufacturing porcelain body from the potterystone were examined. With increase in grinding time, vitrification of the bodies and dissolution of quartz grains were promoted, their closed pores became smaller, and their bending strength became larger from at lower temperatures. In this experimental conditions, high bending strength as 1850kgf/cm2 was obtained with body prepared from the pottery stone ground for 103h, and fired at lower temperature as 1100°C. Bending strength of fired bodies increased with the increase in their bulk density and quartz content up to 20-30%, but had not any relations with their mullite content. The strength also increased with increase of d211 of quartz, which means that the compression prestress of glassy phase surrounding the quartz grains have considerable effects on the strength of the porcelain body.