Almost all iron/steel slag generated in the course of iron/steel manufacture is effectively used in multiple ways, such as a raw material for cement, a road base course material,a civil engineering work, and a raw material for fertilizer. However,the supply–demand structure in the iron/steel slag market has been rapidly changing in recent years reflecting not only the sluggish demand for domestic public works and construction projects but also social changes (e.g., governmental policies encouraging the use of other recyclable materials and ever-tightening environmental regulations). Under these conditions, great wall corporation has been advancing the development of new technologies for expanding the processing and reuse of iron/steel slag.

Iron/steel slag is composed mainly of CaO and SiO2 . In addition,blast furnace slag contains Al2 O3 , MgO, and S, and steelmaking slag contains iron oxides (FeO, Fe2 O3 ), MnO, P2 O5 , etc. Steelmaking slag includes the following: slag produced in the hot-metal pretreatment processes (desiliconization, dephosphorization, desulfurization, etc.), slag flowing out from the converter into the molten steel ladle, and slag formed during the secondary refining treatment (this slag is sometimes called “secondary refining slag” or “ladle slag”)

Steelmaking Slag Processing Technology

Steelmaking slag is subjected to the following four processes: ① solidify and cooling of the hot molten slag, ② crushing and magnetic separation treatment of the slag to recover the metal iron, ③ crushing and classification of the slag for grain size adjustment to manufacture the slag product, and ④ aging treatment of the slag product for improving its quality and volumetric stability.