Producing low fluorine mold powder by replacing CaF2 with Na2CO3, ZnO and Fe2O3

Document Type: Research Paper

Authors

Department of Materials Engineering, Najaf Abad Branch, Islamic Azad University, Esfahan, Iran

Abstract

Mold powders in continuous casting of steel contain fluorine through mainly CaF2 and occasionally NaF and Na3AlF6. Fluorine develops dangerous gases such as SiF4 and HF at high temperatures. In this study, CaF2 is partly replaced by substances such as Na2CO3, ZnO and Fe2O3.Sulfur free Portland cement clinker containing gypsum was used as a new product base. These additions developed comparable viscosity to the industrially used powder. In order to compare the viscosity of laboratory samples with the reference sample, study the crystalline behavior of samples, and compare them to the reference sample, there were performed sloped plate groove viscometer, XRD and SEM studies. It can be detected the Crystalline phases such as Gehlenite, Nepheline, Akermanite, Cuspidine, Na2ZnSiO4, Ca2ZnSi2O7, Ca3SiO5 and Mn3O4, Fe2SiO4. In order to develop less toxic mold powder in continues casting of steels, it is proposed being crystalline and glassy with comparable viscosity.

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