GRANULATED SLAG-FORMING MIXTURE AND METHOD FOR ITS PRODUCTION Russian patent published in 1994 - IPC

FIELD: metallurgy. SUBSTANCE: granulated slag-forming mixture contains granules with fraction sizes, mm: 0.05-0.15; 0.15-0.30; 0.3-1.0; and 1.0-1.5 with ratio (0.2-8.0):(0.3-12.0):(60-99):(0.5-20.0) and each granule of mixture is hollow with volume of spherical hollow amounting up 0.12-0.80 of granule volume. 30-80% of granule outer surface is coated with carbon particles. Method for production of mixture is characterized by introduction of graphite into 15-25% aqueous solution of calcium chloride heated up to 30-50 C and mixed with suspension of other ingredients. Mixed suspension of all ingredients is sprayed into atmosphere of products of incomplete combustion of fuel moved in direction square to flow of drops and having temperature of 540-680 C. Granulometric composition and structure of mixture granules produced by the offered method provides for homogeneity of chemical composition of slag melt film, uniform heat removal from forming skin of casting and reduction of lateral cracks down to 0.2-0.6 per meter of casting. Mixture consumption equals 0.5-1.5 kg per ton of steel. EFFECT: reduced difference in thickness of forming casting skin and number of lateral cracks of casting surface. 2 cl, 3 tbl