METHOD OF MANUFACTURING PRODUCTS Russian patent published in 1997 - IPC

FIELD: manufacture of building materials. SUBSTANCE: invention deals with manufacturing facing slabs, dalles, and cutting tool bodies. Invention aims at improving architectural appearance of products and creating thixotropy of molding mixture with B/T = 0.2-0.3, as well as reducing period of time required for actual hardening without reducing time of possible dismantling of forms for products with thickness less than 30 mm under natural conditions of hardening without or with preheating at 60 C. Invention also intends to enlarge the resource for reuse of iron- containing disperse-reinforcing wastes from other production areas with no decrease in strength. Method of invention includes preparing molding compound by mixing caustic magnesite with ground basic blast- furnace slag, disperse-reinforcing iron-containing component with particle size less than 0.63 mm, and magnesium chloride solution with density 1.3 g/cu.cm. Thereafter products are molded with vibrational compacting and aging in molds until dismantling is accomplished. Method is distinguished by that caustic magnesite and ground basic blast-furnace slag are first mixed and resultant mixture is added under vigorous stirring to magnesium chloride aqueous solution with density 1.3 g/cu. cm preheated to 70 C, and then, with stirring not interrupted, disperse-reinforcing iron-containing component is added. The thus obtained blend is cooled and alkali-neutralized polyvinylacetate emulsion with density 1.1 g/cu. cm is added. Prior to molding, compound is supplemented with hydrated lime in amount 1.5-3% above 100% based on weight of molding compound. The latter is composed, wt. -%: caustic magnesite, 21.1-28.6; ground basic blast-furnace slag, 30.4-36.4; magnesium chloride solution (on conversion to solid material), 8.18-11.7; disperse-reinforcing iron- containing component, 9.5-12.5; polyvinylacetate emulsion, 0.9-1.0; water, the balance. As disperse-reinforcing iron-containing component, subjected to high-temperature heat treatment and containing less than 50% of iron-containing particles, waste is utilized selected from the group including blast-furnace dust, magnetoactive brown-coal ashes, cyclone dust from cleaning of steel accessories with shot-blasting apparatus, and iron-containing waste from electromagnetic cleaning of chamotte powders. Open surface of molded products is tightly covered with adhesive steam- and air-proof film and kept until dismantling is accomplished. EFFECT: increased economical efficiency of process. 1 tbl