Research on effect of CaO/SiO2 on recovery iron from converter slag under smelting condition

How to increase the ration of iron and heat recovery from the smelting steel slag is an important issue in metallurgy. So a study of extracting iron from converter slag was done by smelting reduction method. Here we studied the effect of CaO/SiO₂ on the recovery during smelting reduction. Results showed that the CaO/SiO₂ directly regulated the reduction reaction of Fe²⁺ / Fe³⁺, the viscosity of slag and separation effect of slag-iron, and thereby affected the recovery ration and metallization ration of iron. And both rations increase first and then decrease as the bascity increased; when CaO/SiO₂ is 1.1, both rations reach at the maximum, 94.40% and 99.09% respectively. Among the slag MFe is the most abundant and disperses as particles; whereas the non-reduced iron exists mainly as Fe²⁺. When the CaO/SiO₂ is less than 1.1, the iron in the slag is mainly in form of MFe; while when the CaO/SiO₂ is more than 1.1, there is also plenty of Fe²⁺/Fe³⁺ in addition to MFe in the slag. This study provides important reference for the iron recovery from the converter slag.