The Environmental Footprint of the Calcination Process in the Steel Industry

Limestone (CaCo3) and dolomite (CaCO3.MgCO3), anhydrous carbonate minerals, are essential raw materials for producing iron and steel. They play an important role in fixing the acidic compounds of undesirable metals and metalloids from the bath to slag. The life cycle assessment method is employed in the present study to assess the cradle-to-gate environmental effects of limestone and dolomite calcination for 1 ton of product as a functional unit using the GaBi software. According to the findings, the impact of lime production on global warming is 298 kg CO2 equiv. and that of calcined dolomite is 164 kg CO2 equiv. Likewise, acidification, eutrophication, and other impact categories are also discussed using the CML 2001 method. It has been noted that the impact categories are influenced by energy consumption and transportation. The results are compared with the energy-based coke oven gas allocation method and indicate a massive increase in all impact categories, including global warming (18705 kg CO2 equiv. for lime and 240 kg CO2 equiv. for calcined dolomite). Allocation strategies ensure that coke oven gas contributes effectively to the calcination process environmental impacts in steel production.