WALL CERAMIC PRODUCTS AND METHOD OF MANUFACTURE THEREOF FROM SAND-CLAY MIXES Russian patent published in 1997 - IPC

FIELD: ceramic production. SUBSTANCE: wall ceramic product is manufactures from raw mix which comprises (wt %): 50-85 clay component; 3-40 quartz sand; 5-15 fireclay; 0.2-15 soda caustic based on Na₂O. Method comprises liquefying clay component, dispersing it at 200-300 C, stirring it with sand and in screw-type mixer and grounding the compound for 3-10 minutes to achieve specific area of 2000-7000 sq.m/g. The mixture is then moistened with soda caustic solution. When briquetting on hydraulic press, moisture content of the compound is 6-8 % and when molding on band type screw, press with the compound previously vacuum treated moisture content of the compound is 12.5-13 %. Molded semifinished products are dried at 120-150 for 2-4 hours and fired isothermally at 950-1000 C for 3-5 hours. Physico-chemical properties of products: water absorption is 4.5-10 %; frost resistance 40-100 cycles; ultimate compressive strength is 35-90 MPa and ultimate bending strength is 18-31 MPa. Products are moisture resistant. and after being dried, they have bending strength of 16-35 MPa. EFFECT: improved properties of the wall ceramic product. 4 cl, 3 tbl