Utilization of converter steel slag by remelting and reducing treatment

Abstract

In China, as by-products of iron and steel industry, the utilization rate of steel slag is still relatively low and its open-air stacking occupies a lot of land, where there is a quite different situation of blast furnace slag as supplementary cementitious material in concrete. Considerable amount of metallic iron and iron oxide are lost within slag. In addition, undesirable volume change occurs when slag used as admixture in construction due to high free-CaO content, limiting its application in cement and concrete industry. In this study, remelting and reducing treatment was conducted to recycle iron and modify the chemical composition of the residue. Results showed that iron oxide could be reduced to iron and adjusting materials were found to promote reduction of iron oxide and stability of slag and separation of iron and slag.