This research aims to investigate the influence of the slag basicity from 1.40 to 1.83 on dephosphorization of the hot metal with a CaO–FeO–SiO2–MgO–Al2O3 molten slag at the low temperature of 1653 K. The results indicated that the dephosphorization ratio was increased with the increase of basicity. Even at the low basicities of 1.73 and 1.83, the dephosphorization ratios can be as high as 77.3 and 80.7%, respectively. With the increase of basicity, the contents of P2O5 and total iron in the slag were increased, whereas the content of MnO was decreased. The distribution ratio of phosphorus was expressed as . The values calculated by the present method are well consistent with the measurement values. Besides, the dark grey phase B and the light grey phase D could be considered as the phosphorus-rich phases containing C2S solid particles.
Get full access to this article
View all access options for this article.
References
1.
IwasakiMMatsuoM.Change and development of steel-making technology. Nippon Steel Tech Rep. 2011;391:88–93.
2.
KawamotoM.Recent development of steelmaking process in Sumitomo metals. J Iron Steel Res Int. 2011;18(S2):28–35.
3.
TanakaSKohiraSWatanabeAet al.Development of the new steelmaking process “ZSP" (zero slag process). NKK Tech Rep. 2000;169:6–10.
4.
OgawaYYanoMKitamuraSet al.Development of the continuous dephosphorization and decarburization process using BOF. Tetsu to Hagane. 2001;87(1):21–28. doi: 10.2355/tetsutohagane1955.87.1_21
5.
LiFSLiXPYangSFet al.Distribution ratios of phosphorus between CaO–FeO–SiO2–Al2O3/Na2O/TiO2 slags and carbon-saturated iron. Metall Mater Trans B. 2017;48(5):2367–2378. doi: 10.1007/s11663-017-1023-8
6.
MaruokaNOnoSShibataHet al.Equilibrium distribution ratio of phosphorus between solid iron and magnesiowustite-saturated Al2O3–CaO–FetO–MgO–SiO2 slag at 1623K. ISIJ Int. 2013;53(10):1709–1714. doi: 10.2355/isijinternational.53.1709
7.
LiGQZhuCYLiYJet al.The effect of Na2O and K2O on the partition ratio of phosphorus between CaO–SiO2–FetO–P2O5 slag and carbon-saturated iron. Steel Res Int. 2013;84(7):687–694. doi: 10.1002/srin.201200216
8.
LiuFYWangGCZhaoYet al.Hot metal dephosphorization by low basicity slag in the early stage of converting process. Ironmak Steelmak. 2019;46(4):392–403. doi: 10.1080/03019233.2017.1403134
9.
WuWDaiSFLiuY.Dephosphorization stability of hot metal by double slag operation in basic oxygen furnace. J Iron Steel Res Int. 2017;24(9):908–915. doi: 10.1016/S1006-706X(17)30133-4
10.
YangXSunFMYangJLet al.Optimization of low phosphorus steel production with double slag process in BOF. J Iron Steel Res Int. 2013;20(8):41–47. doi: 10.1016/S1006-706X(13)60139-9
11.
TianZHLiBHZhangXMet al.Double slag operation dephosphorization in BOF for producing low phosphorus steel. J Iron Steel Res Int. 2009;16(3):6–14. doi: 10.1016/S1006-706X(09)60036-4
12.
WangXHZhuGSLiHBet al.Investigation on “slag-remaining + double-slag” BOF steelmaking technology. China Metallurgy. 2013;23(4):40–46.
13.
HeXFWangXHChenSHet al.Experimental investigation on dephosphorization for converter using double slag process in Pangang. Iron Steel. 2012;47(4):32–37.
14.
WanXFCaoDLiDGet al.Technical study and practice on deep dephosphorization with double slags in converter in Ansteel. Iron Steel. 2012;47(6):32–36.
15.
YangXMatsuuraHTsukihashiF.Condensation of P2O5 at the interface between 2CaO·SiO2 and CaO–SiO2–FeOx–P2O5 slag. ISIJ Int. 2009;49(9):1298–1307. doi: 10.2355/isijinternational.49.1298
16.
LinYLiuYChouKet al.Effects of oxygen atmosphere, FeOx and basicity on mineralogical phases of CaO–SiO2–MgO–Al2O3–FetO–P2O5 steelmaking slag. Ironmak Steelmak. 2019;46(10):987–997. doi:10.1080/03019233.2018.1470362.
17.
ShuQFLiuY.Effects of basicity, MgO and MnO on mineralogical phases of CaO–FeOx–SiO2–P2O5 slag. Ironmak Steelmak. 2017;45(4):363–370. doi: 10.1080/03019233.2016.1274463
18.
ShimauchiKIKitamuraSYShibataH.Distribution of P2O5 between solid dicalcium silicate and liquid phases in CaO–SiO2–Fe2O3 system. ISIJ Int. 2009;49(4):505–511. doi: 10.2355/isijinternational.49.505
19.
KitamuraSYMiyamotoKIShibataHet al.Analysis of dephosphorization reaction using a simulation model of hot metal dephosphorization by multiphase slag. ISIJ Int. 2009;49(9):1333–1339. doi: 10.2355/isijinternational.49.1333
20.
MonaghanBJPomfretRJColeyKS.The kinetics of dephosphorization of carbon-saturated iron using an oxidizing slag. Metall Mater Trans B. 1998;29(1):111–118. doi: 10.1007/s11663-998-0013-2
21.
XiaYJGuoXLiJet al.Effect of adding mode of iron oxide on dephosphorization behavior with the recycling of decarburization slag. Steel Res Int. 2018;89(8):1800104. doi: 10.1002/srin.201800104
22.
ZhuCYLiGQChenZPet al.Manganese distribution equilibrium between CaO–FetO–SiO2–MnO–P2O5–(Al2O3) slags and carbon saturated iron. ISIJ Int. 2008;48(2):123–129. doi: 10.2355/isijinternational.48.123
23.
BanYS.Mathematical expression of slag-metal reactions in steelmaking process by quadratic formalism based on the regular solution model. ISIJ Int. 1993;33(1):2–11. doi: 10.2355/isijinternational.33.2
24.
BasuSLahiriAKSeetharamanS.Phosphorus partition between liquid steel and CaO–SiO2–P2O5–MgO slag containing low FeO. Metall Mater Trans B. 2007;38(3):357–366. doi: 10.1007/s11663-007-9057-y
25.
TurkdoganET.Assessment of P2O5 activity coefficients in molten slags. ISIJ Int. 2000;40(10):964–970. doi: 10.2355/isijinternational.40.964
26.
ShimJ-DBanYS.The solubility of magnesia and ferric-ferrous equilibrium in liquid FetO–SiO2–CaO–MgO slags. Tetsu to Hagane. 1981;67(10):1735–1744. doi: 10.2355/tetsutohagane1955.67.10_1735
27.
WatanabeYKitamuraKRachevIPet al.Thermodynamics of phosphorus and sulfur in the BaO–MnO flux system between 1573 and 1673 K. Metall Trans B. 1993;24(2):339–347. doi: 10.1007/BF02659137
28.
PakJJFruehanRJ.The effect of Na2O on dephosphorization by CaO-based steelmaking slags. Metall Trans B. 1991;22(1):39–46. doi: 10.1007/BF02672525
29.
SuitoHInouceR.Effects of Na2O and BaO additions on phosphorus distribution between CaO–MgO–FetO–SiO2-slags and liquid iron. Trans ISIJ. 1984;24(1):47–53. doi: 10.2355/isijinternational1966.24.47
30.
ImJMoritaKSanoN.Phosphorus distribution ratios between CaO–SiO2–FetO slags and carbon-saturated iron at 1573 K. ISIJ Int. 1996;36(5):517–521. doi: 10.2355/isijinternational.36.517
31.
HealyG.New look at phosphorus distribution. J Iron Steel Inst. 1970;208(7):664–668.
32.
SuitoHInoueR.Phosphorus distribution between MgO-saturated CaO–FetO–SiO2–P2O5–MnO slags and liquid iron. Tetsu to Hagane. 1984;70(2):186–193. doi: 10.2355/tetsutohagane1955.70.2_186
33.
IdeKFruehanR.Evaluation of phosphorus reaction equilibrium in steelmaking. Iron Steelmak. 2000;27(12):65–70.
