The high-P content in convert slag limits its recycling in the steelmaking process. The P could be removed out of the slag as gas when the convert slag is reduced by reductants, such as carbon. Through the experiments and thermodynamic calculations, one of the main dephosphorization products is determined to be P2 as the converter slag being reduced by C. In the experiments, the reduction driving force of P2O5 is greater than that of FeO; while the actual Gibbs free energy of P2O5 is lower than that of FeO at a high temperature in the atmosphere of flowing N2. The dephosphorization of converter slag conforms to the interface chemical reaction model, and a model was established to describe the dephosphorization process in this study. The results indicate the apparent activation energy of the dephosphorization reaction is 165.78 kJ mol−1 and the dephosphorization reaction is controlled by the mass transfer of reactants in the slag.
Get full access to this article
View all access options for this article.
References
1.
JiangMFCuiYYWangDYet al.Effect of Modification Treatment for Reduction of Dephosphorization Slag in Hot Metal Bath. J Iron Steel Res Int. 2013;20(1):1–20.
2.
JungSMDoYJ.Reduction behaviour of BOF slags by carbon in iron. Steel Res Int. 2006;77(5):312–316.
3.
SukMOJoSKKimSHet al.X-ray observation of phosphorus vaporization from steelmaking slag and suppression method of phosphorus reversion in liquid iron. Metall Mater Trans B. 2006;37(1):99–107.
4.
QianQ.Analysis of rock facies structure of converter slag under different processing methods. Sichuan Metallurgy. 2019;41(2):48–51.
5.
IshikawaM.Reduction behaviors of hot metal dephosphorization slag in a slag regenerator. ISIJ Int. 2006;46(4):530–536.
6.
WangSHWuYQLiuXSet al.Experimental Study on Gasification Dephosphorization of Converter Slag With Reduction by Silicon. Iron Steel. 2008;43(2):31–35.
7.
WangSHWuYQXuZRet al.Thermodynamic analysis of gasification and dephosphorization of silicon reduction converter slag. Steelmaking. 2008;24(1):31–34.
8.
LiGQZhangFZhangLet al.Recycle of Converter Slag by High Temperature Carbon Thermal Reduction. J Mater Metall. 2003;3(2):167–172.
9.
LiuLXWangLQLiHet al.Process of Micropowders with Steelmaking Slag. Metall Equip. 2019;1:55–57.
10.
WangDGLiLXiaYJet al.Dephosphorization behavior in CaO-SiO2-Al2O3-Fe2O3 slag system. J Iron Steel Res. 2016;28(7):20–25.
11.
KitamuraSAokiHOkohiraK.Dephosphorization reaction of chromium containing molten iron by CaO-based flux. ISIJ Int1994;34(5):401–407.
12.
OgawaYYanoMKitamuraSet al.Development of the continuous dephosphorization and decarburization process using BOF. Testu-to-Hagane. 2001;87(1):21–28.
13.
UekiTFujiwaraKYamadaNet al.Proc. of 10th Japan-China Symp. on Science and Technology of Iron and Steel, ISIJ, Tokyo, (2004), 116.
14.
TurkdoganET.Assessment of P2O5 activity coefficients in molten Slags. ISIJ Int. 2000;40(4):964–970.
15.
ChenYJ.Application of Steel Slag Tailings in Converter Slagging. Shanxi Metall. 2018;41(6):19–22.
16.
WuQFBaoYP.LinLet al.Phases of converter slagand their cooling precipitation. J Wuhan Univ Sci Technol (Nat Sci Ed). 2014;6(37):411–414.
17.
WuM.Low carbon steel production with BOF slag-remaining practice. Steelmaking. 2009;25(2):16–19.
18.
WuXRAnJNChenRH.Distribution and Concentration of Phosphorus in Factory Converter Slags and Growth of P-concentrating Phase. J Anhui Univ Technol (Nat Sci). 2010;3(27):233–237.
19.
WangNLiangZGChenMet al.Enrichment Behavior of Phosphorus in CaO-SiO2-FetO-P2O5 Slag. J Northeastern Univ (Nat Sci). 2011;32(6):814–817.
20.
LiCXLiHZhouB.et al.Experimental study on steelmaking using limestone instead of lime as the slagging material in 100t converter. Chin Metall. 2015;25(12):22–26.
21.
LiangYJCheCY.Handbook for inorganic thermodynamic calculation; 2001. p. 219–222.
22.
LiuJXiaJPChenZJet al.Yellow Phosphorus Production in Electric Furnace Using Potassium Feldspar to Replace Silica as Flux. J Chem Eng Chin Univ. 2017;31(6):1419–1425.
23.
MengHLuSW.Safety risks analysis and precautions for yellow phosphorus production with electric furnace process. Inorg Chemicals Ind. 2014;46(06):56–58.
24.
CuiHXChenQWShenYYet al.Technology Research on Phosphorus Enrichment and Application of Converter Steel Slag. Chin Metall. 2010;20(3):35–38.
25.
ChenSJ. Effect of physicochemical properties of phosphate rock on phosphorus production operation in electric furnace. SP & BMH Relat Eng. 2010;5:33–40.
26.
LvYZhangMAiLQet al.Experimental research on dephosphorization of converter slag by microwave heating and carbon thermal reduction. Steelmaking. 2010;4(26):70–74.
27.
HuangXG.Principles of iron and steel metallurgy. Beijing, China: Metallurgical Industry Press; 1990. p. 180–182
28.
HanQY.Metallurgical process dynamics [M]. Beijing, China: Metallurgical Industry Press; 1983. p. 93–106.
29.
ChenJX.Data manual for commonly used icons in steelmaking, 1984.
30.
WangJY.German Association of Steel Engineers (Slag Atlas), 1983.
31.
Ono-NakazatoHYonezawaTUsuiT.Effect of water-gas shift reaction on reduction of iron oxide powder packed bed with H2-CO mixtures. ISIJ Int. 2003;43(10):1502–1511.
32.
ZhangWWangHXingHWet al.Kinetic Study for Gasification Dephosphorization of High-phosphorus Oolitic Hematite. Mining Metall Eng. 2015;35(3):79–82.
