Control of Slag and Insoluble Buildup in Ladles, （控制钢包渣和不可溶性累积的）.pdf

Control of Slag and Insoluble Buildup in Ladles, Melting and Pressure Pour Furnaces By R. L. (Rod) Naro, ASI International, Ltd., Cleveland, Ohio Dave Williams, Allied Mineral Products, Inc., Columbus, Ohio Pete Satre, Allied Mineral Products, Inc., Columbus, Ohio Introduction: During the past 30 years, the melting methods and associated molten metal-handling systems used by the U.S. foundry industry have changed significantly. During the same period, while ductile iron production has experienced continued growth, the quality of metallic scrap and other iron- unit feed stocks has steadily deteriorated. The result: slag related melting problems have become widespread issues in recent years. Yet, a search of the foundry technical literature from the past 30 years about slag control and buildup will result in only a handful of articles. A new flux, Redux EF40L, has been developed that controls and minimizes buildup in pouring ladles, melting furnaces, pressure pour furnaces and magnesium treatment vessels with minimal to no adverse effects on refractory linings. Slag Formation: The formation of slag in the melting of ferrous metals in the foundry is inevitable. The composition of slag varies with the type of melting process used and the type of iron or steel being melted. The cleanliness of the metallic charge, often consisting of sand-encrusted gates and risers from the casting process or rust- and dirt-encrusted scrap, significantly affects the type of slag formed during the melting operation. Additional oxides or nonmetallic compounds are formed when liquid metal is treated with materials to remove impurities or to change the chemistry of the system (inoculation and nodulizing). Because these oxides and n