Deoxidation of iron melt with immersed MgO-C porous tube

Abstract

In the present study, the deoxidation of iron melt is performed by immersing MgO-C porous tube with and without evacuating its inside. It is found that Mg vapor produced by the reaction between MgO and C of the tube takes part in the deoxidation process. The deoxidation product in a gaseous form (CO) is easily removed from the melt and the product in a solid form (MgO) attaches on the tube surface or floats up to the free surface of the melt. Reducing the internal pressure of the tube enhances the carbon-oxygen reaction. The amount of removed oxygen from the melt increases with initial oxygen content of the melt. This is because of higher efficiency of reaction between Mg vapor and oxygen in the melt. Initial carbon supply from the porous tube is large and hence, the carbon content in the melt increases rapidly at the initial stage of the reaction. At higher initial oxygen content, intensive CO boiling occurs in the melt. Under this condition the carbon content of the tube does not show an appreciable effect on the deoxidation rate. The oxygen supply by the dissociation of MgO crucible prevents the oxygen content of the melt from decreasing to <20ppm.