FILLER FOR BURNING-INHIBITING COATINGS Russian patent published in 2004 - IPC

FIELD: foundry, namely manufacture of burning-inhibiting coatings for casting molds and cores. SUBSTANCE: slag formed at remelting secondary aluminum alloys is used as filler for coating compositions. Said slag contains metallic aluminum in quantity 3.4 - 23.2 mass% and silica in quantity 6.85 mass%. Due to presence of Al₂O₃ and SiO₂, having high refractoriness, thermal burning on castings is reduced. Metallic aluminum in the result of contact with melt forms additional quantity of Al₂O₃. Use of flux components provides formation at high temperature of activated gas phase in the form of chlorine-, fluorine- and hydrogen-containing ions and radicals. When metallic aluminum, slag and iron from melt metal react with said gas phase chlorides are formed. Said chlorides form "crust" preventing realization of chemical reactions between casting and mold. EFFECT: enhanced quality of castings due to complex action of slag. 2 tbl