Life cycle inventory processes of the integrated steel plant (ISP) in Krakow, Poland-continuous casting of steel (CCS): a case study

PurposeThe purpose of this study is to perform the life cycle inventory (LCI) to continuous casting of steel (CCS) process in integrated steel plant (ISP) in Krakow, Poland. The present LCI is representative for year 2015 by application of PN-EN ISO 14040 (2009). The system boundary was labeled as gate to gate. The background input and output data from the CCS has been inventoried as follows: consumption of energy and fuels, materials inputs, and waste.MethodsIn this paper, LCI CCS process on integrated permit (secondary data), literature information, and expert consultations was developed. The functional unit (FU) is represented by 1 t of steel slabs produced by CCS. Operating parameters as well as air emissions associated with the CCS process were presented. The production data (slabs) was given. The emissions of dust, Fe, PM10 and PM2.5, and waste (iron dust, iron particles, the others) are outcomes of the CCS processes.Results and discussionAnnually production of steel slabs in CCS plant amounted to 200,000 t. Coke oven gas, natural gas, steam, air, oxygen, casting powders for crystallizer and for intermediate tundish, refractory material, oil, lubricant, argon, and industrial water amounts were in the order of 2,750,000 Nm3/year, 770,000 Nm3/year, 2000 t/year, 90,000,000 Nm3/year, 970 t/year, 1300 t/year, 810 t/year, 30 t/year, 45 t/year, 330 t/year, and 13,175,300 m3/year, respectively. The average heat and electric energy consumptions were about 0.023 to 0.068 GJ/t and 12.0 to 17.2 kWh/t, respectively. Emissions in air of dust, Fe, PM10, and PM2.5 were in the order of 1.3, 0.1, 0.5, and 0.44 kg/h, respectively. The amounts of iron dust and the other waste were 200 t/year and 240 t, respectively. No information is available on CO2 emission.ConclusionsThe LCI study resulted in the development of a database with an inventory of secondary data regarding CCS process referring to the year 2015. The scope of this study considered input items needed in CCS production (entry gate) to the final delivery of steel slabs (exit gate). The raw materials, supplies, and equipment to the CCS plant and infrastructure are not taken into consideration in the analysis. The FU is 1 t of steel slabs.Recommendations and outlookThe LCI offers environmental information consisting of the list of environmental loads. The impact assessment phase aims to present more understandable results from the inventory analysis, and life cycle impact assessment will be the direction for future research.