SILICEOUS CERAMICS AND METHOD OF MANUFACTURE OF SUCH CERAMICS Russian patent published in 2002 - IPC

FIELD: manufacture of building and road materials; manufacture of self-glazing ceramic articles, border stone, face bricks, pavement and facing slabs. SUBSTANCE: method consists in joint milling of finely-dispersed silica, 10-90; calcium oxide, 2-5; and bischofite, 0.5-1.5 till material at specific surface of 3500-5000 sq.cm/g has been obtained. Added to finely-milled mixture is quartz sand and aqueous solution of sodium hydroxide, 1-7 in terms of Na₂O). Amount of water shall ensure moisture content of mixture being molded between 7 and 8% for dry-press process of molding and 9-12% for vibroforming. Surface-active agent in the amount of 0.1-0.5% is added to mixture for imparting plasticity; then it is subjected to aeration in high-speed stirrer continued for 2 min. Molded articles are dried in stage-by-stage mode at stand at 90- 140-200 C; burning is performed at 790-840 C. Mode of burning is dictated by maximum permissible differential of temperatures between surface and center of article. Calculation is made according to special formula given in the specification. EFFECT: enhanced strength, water- and frost resistance. 3 cl, 2 dwg