HIGH STRENGTH FELDSPATHIC PORCELAIN AND METHOD FOR PRODUCING THE SAME

摘要

Abstract of the DisclosureHigh strength porcelain having an unglazedbending strength of more than 1,400 kg/cm2 and consistingessentially of 22-85% by weight of SiO2, 10-73% byweight of A?2O3, and 1.5-6.5% by weight of K2O and/orNa2O. The porcelain has a total degree of crystallinityof more than 40% by weight, and a crystalline grainsize of not greater than 20 µm, and it is free fromdefects of larger than 40 µm. The porcelain is producedby pulverizing a starting material mixture of quartz-feldspar-alumina system so that 85-95% by weight ofparticles thereof have a grain size of not greater than10 µm, calcining the mixture, adding clay-mineralmaterial therein, pulverizing so that the clay-mineral-added mixture contains less than 85% by weight ofparticles with a grain size of not greater than 10 µm,forming, drying, and firing at 1,000-1,400°C.