SLAG-FORMING MIXTURE FOR CONTINUOUS RAIL STEEL CASTING Russian patent published in 2011 - IPC B22D11/111 

FIELD: chemistry.

SUBSTANCE: invention relates to ferrous metallurgy, specifically to compositions of slag-forming mixtures used in continuous steel casting, particularly for making railway rails. The slag-forming mixture is obtained by mixing amorphous graphite, fluorspar concentrate and materials containing oxides of silicon, aluminium and alkali metals. The materials containing oxides of silicon, aluminium and alkali metals used is a mixture which contains finely ground pegmatite KPSTM 0.2-2.0, calcined soda and finely ground quartzite. The components are taken in the following ratio, wt %: amorphous graphite 17-23, fluorspar concentrate 9-15, finely ground pegmatite 17-39, calcined soda 1-12, finely ground quartzite 1-13, cement - the rest. The mixture has basicity (CaO/SiO₂) 0.6-0 and the following chemical composition in wt %: C 13.0-19.0, CaO 22.0-28.0, SiO₂ 30.0-36.0, Al₂O₃ 5.0- 8.5, F 4.0-7.0, (Na⁺+K⁺) 3.0-12.0.

EFFECT: high assimilative capability of the mixture with respect to non-metallic inclusions, high quality o steel owing to an improved macrostructure, reduced surface defects of workpieces owing to improved mould lubrication.

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