One of the most effective ways to reduce carbon dioxide (CO2) emissions in the oxygen steelmaking process is to lower the hot metal ratio (HMR) in the basic oxygen furnace (BOF). However, if the HMR is lowered, the amount of oxygen blowing during decarburisation in the BOF converter increases due to a lack of heat source. This reduces the cleanliness of the molten steel because the end point oxygen content in the molten steel increases. Hence, we sought to ensure the molten steel quality even at a decreased HMR of about 10%p compared to the current level to reduce carbon emissions in BOF steelmaking. An appropriate amount of silicon in hot metal was suggested to maintain the lowered HMR. In addition, a process optimisation for solving dephosphorisation as well as tramp elements problem was proposed even if the scrap charge increased. As a result, CO2 emissions from steel mills decreased from 2.20 t-CO2/t-steel to 2.06 t-CO2/t-steel.
MadhavanNBrooksGARhamdhaniMA, et al.Application of mass and energy balance in oxygen steelmaking. Ironmak Steelmak2021; 48: 995–1000.
11.
WangCRymanCDahlJ. Potential CO2 emission reduction for BF–BOF steelmaking based on optimised use of ferrous burden materials. Int J Greenhouse Gas Control2009: 29–38. https://doi.org/10.1016/j.ijggc.2008.06.005
12.
GuptaPKumarSBabuJH, et al.Production of low phosphorous steel from low silicon high phosphorous hot metal in BOF. Ironmak Steelmak2023. https://doi.org/10.1080/03019233.2023.2173877
13.
MaoWWLiCXLuH, et al.Silicon volatilisation in the form of SiO during slagging by limestone in BOF. Ironmak Steelmak2017; 44: 389–393.
14.
ItohYSatohSKawauchiY. Development of slag minimum refining process by desiliconization of hot metal. ISIJ Int1983; 23: 256–265.
15.
BarellaSCeccaCDMapelliC, et al.Study of a new operating practice for refining high silicon hot metal in a BOF converter. Steel Res Int2016; 87: 941–946.
16.
DaiYLiJShiC,et al.Dephosphorization of high silicon hot metal based on double slag converter steelmaking technology. Ironmak Steelmak2021; 48: 447–456.
17.
YangWYangJShiY, et al.Effect of basicity on dephosphorization of hot metal with a low basicity slag at 1653 K. Ironmak Steelmak2021; 48: 69–77.
18.
TianZLiBZhangX,et al.Double slag operation dephosphorization in BOF for producing low phosphorus steel. J Iron Steel Res Int2009; 16: 06–14.
19.
ZhangRYangJYangW,et al.Kinetics of dephosphorization in double slag converter steelmaking process at different temperatures with industrial experiments and laboratorial experiments. Metall Mater Trans B2022; 53: 3013–3024.
20.
ZhangRYangJSunH,et al.Kinetics of dephosphorization at different slag basicities in the double slag converter steelmaking process. Steel Res Int2021; 92: 2100256.
21.
YangWYangJZhangR, et al.Effect of the basicity on mineralogical phases and micro-structure of dephosphorization slag in the new double slag converter steelmaking process. MDPI Metals2021; 11: 1480.
22.
SunHYangJLuX, et al.Dephosphorization in double slag converter steelmaking process at different temperatures by industrial experiments. MDPI Metals2021; 11: 1030.
23.
KovtunOKarbayevMKorobeinikovI, et al.Phosphorus partition between liquid crude steel and high-basicity basic oxygen furnace slags. Steel Res Int2021; 2000607. https://doi.org/10.1002/srin.202000607
24.
ZhouCChenQJiY, et al.Effect of highly oxidizing converter dephosphorization slag on dephosphorization behaviour of molten steel. Ironmak Steelmak2023. https://doi.org/10.1080/03019233.2023.2168344
25.
YangJZhangRYangW,et al.Dephosphorization at low temperature and low basicity in the double slag converter steelmaking process with Low CO2 emission. Int Congr Sci Technol Steelmak2022. DOI https://doi.org/10.33313/531/021
26.
WangMYangW. Dephosphorization in the early stage of converter steelmaking. Ironmak Steelmak2020; 47: 1127–1134.
27.
YaoLZhuRDongK, et al.Influence of the non-uniform bottom blowing gas supply mode on the dynamic conditions of molten pool during the converter steelmaking process. Ironmak Steelmak2021; 48: 180–190.
28.
LiuGLiuKHanP. Metallurgical performance of innovative double-parameter oxygen lance in BOF steelmaking. Ironmak Steelmak2021; 48: 437–446.
29.
ZhouYZhuRHuS,et al.Study on metallurgical characteristics of the bottom-blown O2–CaO converter. Ironmak Steelmak2021; 48: 142–148.
30.
OhMKKimTSParkJH. Effect of CaF2 on phosphorus refining from molten steel by electric arc furnace slag using direct reduced iron (DRI) as a raw material. Metall Mater Trans B2020; 51: 3028–3038.
31.
CheremisinaELesiakSRiegerJ, et al.Assessment of the dissolution rate and behaviour of raw dolomite and limestone with different calcination degrees in primary steelmaking slags. Ironmak Steelmak2023; 50: 379–391.
32.
LiuYZhangPTianY, et al.Role of self-disintegrating effect produced by decomposition of limestone core on accelerating dissolution of lime in CaO–SiO2–FeOx slag. Ironmak Steelmak2023. https://doi.org/10.1080/03019233.2023.2217026
33.
MurakiMFukushimaHSanoN. Phosphorus distribution between CaO-CaF2-SiO2 melts saturated with solid CaO compounds and carbon-saturated iron. Tetsu-to-Hagane1985; 71: 693–699.
34.
SuitoHInoueR. Thermodynamic assessment of hot metal and steel dephosphorization with MnO-containing BOF slags. ISIJ Int1995; 35: 258–265.
35.
TabataYTeradaOHasegawaT, et al.Manganese partition equilibrium in less slag blowing at BOF linked to high speed dephosphorization of hot metal. Tetsu-to-Hagane1990; 76: 1916–1923.
36.
KunisadaKIwaiH. Rate of dephosphorization of liquid iron by the slag of CaO-SiO2-FeO system. Tetsu-to-Hagane1984; 70: 1681–1688.
37.
KitamuraSKitamuraTShibataK, et al.Effect of stirring energy temperature and flux composition on hot metal dephosphorization kinetics. ISIJ Int1991; 31: 1322–1328.
38.
ZhangRYangJYangW,et al.Kinetic model of dephosphorization in the new double slag converter steelmaking process. Ironmak Steelmak2021; 48: 1277–1290.
39.
YangWYangJZhangR,et al.Microstructure and viscosity of dephosphorization slag in new double slag converter steelmaking process. ISIJ Int2021; 61: 2490–2500.
40.
AbeKAokiT. Steelmaking process, 1959.
41.
YangWYangJShiY, et al.Effect of temperature on dephosphorization of hot metal in double-slag converter steelmaking process by high-temperature laboratorial experiments. Steel Res Int2021; 92: 2000438.
42.
KitamuraSYonezawaKOgawaY,et al.Improvement of reaction efficiency in hot metal dephosphorisation. Ironmak Steelmak2002; 29: 121–124.
43.
MoriKFukamiYKawaiY. Rate of dephosphorization of liquid iron-carbon alloys by molten slags. ISIJ Int1988; 28: 315–318.
44.
WangXTangFLiZ, et al.Development of a high-efficiency dephosphorization process via the fine in situ phases due to the composite ball explosion. Ironmak Steelmak2021; 48: 1110–1114.
45.
DrainPBMonaghanBJZhangG, et al.A review of phosphorus partition relations for use in basic oxygen steelmaking. Ironmak Steelmak2017; 44: 721–731.
46.
DeoBHalderJSnoeijerB, et al.Effect of MgO and Al2O3 variations in oxygen steelmaking (BOF) slag on slag morphology and phosphorus distribution. Ironmak Steelmak2005; 32: 54–60.
HanXLiJZhouCG, et al.Study on mineralogical structure of dephosphorisation slag at the first deslagging in BOF steelmaking process. Ironmak Steelmak2017; 44: 262–268. https://doi.org/10.1080/03019233.2016.1210371
YoshidaKTamazakiITozakiY, et al.Development of effective refining process consisting of both hot metal pretreatment and decarburization in two top and bottom blown converters. ISIJ1990; 76: 53–58. https://doi.org/10.2355/tetsutohagane1955.76.11_1817
54.
ShiwakuKKawasakiSKamimoriA, et al.Sequential dephosphorization and desulphurization of hot metal by newly developed pretreatment furnace. ISIJ1987; 73: 1567–1574. https://doi.org/10.2355/tetsutohagane1955.73.11_1567
55.
KimKH. A Study on the Dephosphorization Efficiency Depending on the Temperature Change before/after the Dephosphorization Process. A Master's Thesis.
OgawaYYanoMKitamuraSHirataH. Development of the continuous dephosphorization and decarburization process using BOF. Tetsu-to-Hagane2001; 87: 21–28. https://doi.org/10.2355/tetsutohagane1955.87.1_21
VorabergerBWimmerGSalgadoUD, et al.(BOF) Steelmaking—reduced CO2 emissions via increased scrap rate. MDPI metals2022; 466. https://doi.org/10.3390/met12030466
61.
RymanCLarssonM. Reduction of CO2 emissions from integrated steelmaking by optimised scrap strategies: application of process integration models on the BF–BOF system. ISIJ Int2006; 46: 1752–1758.
DaiYLiJYanW,et al.Corrosion mechanism and protection of BOF refractory for high silicon hot metal steelmaking process. J Mater Res Technol2020: 4292–4308. https://doi.org/10.1016/j.jmrt.2020.02.055
67.
LiuFWangGZhaoY, et al.Hot metal dephosphorisation by low basicity slag in the early stage of converting process. Ironmak Steelmak2019; 46: 392–403.
68.
KimGEOhHSLeeJH, et al.Development of alternative reductant using biomass for reducing CO2 in ironmaking process. Korea J Met Mater2023; 61: 218–230.
69.
ParkJWKimMKSuhIK, et al.Investigation of carburization and melting behavior of fully reduced LRI and IOS on coke substrates. Met Mater Int2023. https://doi.org/10.1007/s12540-023-01551-2
70.
SuerJTraversoMJägerN. Review of life cycle assessments for steel and environmental analysis of future steel production scenarios. MDPI Sustainability2022; 14131. https://doi.org/10.3390/su142114131
71.
DongWXuALiH, et al.Study on the reaction behavior of CO2 with molten steel in converter process by top blowing mixed CO2–O2 gas. Metall Mater Trans B2022; 53: 3575–3584.
