| 摘要 |
<p>High strength porcelain having an unglazed bending strength of more than 1,400 kg/cm2 and consisting essentially of 22-85% by weight of SiO2, 10-73% by weight of A?2O3, 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 porcelain is produced by pulverizing a starting material mixture of quartzfeldspar-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 1,000-1,400.degree.C.</p> |
