| 摘要 |
High strength porcelain having an unglazed bending strength of greater than 1,400 kg/cm2 and consisting essentially of 22-85% by weight of SiO2, 10-73% by weight of Al2O3, and 1.5-6.5% by weight of K2O and/or Na2O. The porcelain has a total degree of crystallinity of more than 40% by weight, and a crystalline grain size of not greater than 20 mu m, and it is free from defects of larger than 40 mu m. The procelain is produced by pulverizing a starting material mixture of quartz-feldspar-alumina system so that 85-95% by weight of particles thereof have a grain size of not greater than 10 mu m, calcining the mixture, adding clay-mineral material therein, pulverizing so that the clay-mineral-added mixture contains less than 85% by weight of particles with a grain size of not greater than 10 mu m, forming, drying, and firing at 1,100 DEG -1,400 DEG C. |
