The Study on the Separation of Steelmaking Slags Using Air Classification

Abstract

The cement industry, one of the major greenhouse gas-emitting sectors in South Korea, produces approximately 39 million tons of greenhouse gases annually, with over half of this emission stemming from the calcination of limestone (CaCO 3 ). This study investigates the behavior of key components in slag generated by Company "P", utilizing ball mill grinding technology and air classification technology to explore the effects of process condition changes. In particular, the study aims to understand the separation behavior of CaO and Fe within the slag through the application of air classification technology. The results indicate that as the rotor speed of the air classifier increases, the CaO content increases by up to 9.97%, while the Fe content decreases by up to 24.27%. Considering the recovery rate, it was determined that operating the rotor at a speed below 5,000 rpm is efficient. This study demonstrates the utility of air classification technology for utilizing slag, a byproduct of steelmaking, as an alternative raw material for cement calcination, confirming the potential to control the contents of CaO, Fe, and Cr in the slag.