Equilibrium distribution ratio of phosphorus between solid iron and magnesiowustite-saturated Al2O3-CaO-FetO-MgO- SiO2 Slag at 1 623 K

Abstract

In the conventional iron-making process, the oxygen potential in the hearth of the blast furnace is determined only by the temperature because of the carbon-saturated conditions. As a consequence, impurities such as phosphorus are reduced and dissolved in the iron because of the excessively low oxygen partial pressure. The oxygen partial pressure can be controlled by using gas reductants such as hydrogen and carbon monoxide. Under these conditions, solid iron is obtained because of the low carbon content. In this study, the equilibrium distribution of phosphorus between the solid iron and molten slag is investigated at 1 623 K as functions of the oxygen partial pressure and the basicity of the slag. The experimental results show that the phosphorus content in the solid iron is sufficiently low under the experimental conditions employed. The phosphate capacity is also evaluated, and a regression equation is obtained by comparing the results with those of previous studies. © 2013 ISIJ.