Steel slag used as metallurgical raw materials

1) Recycling scrap steel, steel slag contains a large amount of iron, with an average mass fraction of about 25%, of which metallic iron accounts for about 10%. After magnetic separation, scrap steel of various particle sizes can be recovered, with most of the high-grade steel slag containing iron used as raw materials for steelmaking and ironmaking.

2) Steel slag is used as a sintering material. Due to the presence of 40% to 50% CaO in converter steel slag, using it as a sintering ingredient instead of some limestone can not only recycle residual steel, iron oxide, calcium oxide, magnesium oxide, manganese oxide, rare elements (V, Nb, etc.) in steel slag, but also increase the number of drum fingers and agglomeration rate, which is beneficial for sintering, pelletizing, and improving sintering speed. The heat generated by the oxidation reaction of Fe and FeO in steel slag can reduce the fuel consumption of sintered ore. 

3) Steel slag is used as a blast furnace flux, and converter steel slag contains 40% to 50% CaO and 6% to 10% MgO. Recycling it as a blast furnace co solvent can replace limestone and dolomite, thereby saving ore resources.

In addition, due to the energy consumption required for the decomposition of limestone (CaCO3) and dolomite [CaMg (CO3) 2] into CaO and MgO, while Ca and Mg in steel slag exist in the form of oxides, a large amount of thermal energy is saved .

4) Steel slag is used as a slag material for steelmaking, and returning it to the converter for smelting can reduce raw material consumption and total slag amount. For smelting itself, it can also promote slagging and shorten smelting time.