In order to the improvement of steel quality and dephosphorization capacity, it is vital to realize the microscopic essence of dephosphorization reaction of the slags. In this work, the temperature dependence of phosphorus distribution ratio and phosphate capacity is discussed with respect to the structure characterized by Raman and MAS-NMR. As the temperature increases from 1550°C to 1600°C, the reduction of Q0(Si) and Q0(P) weakens the formation of the Si–O–Ca–O–P linkages that can stabilize the silicate and phosphate network, which is not conducive to the increase of phosphorus distribution ratio and phosphate capacity. Meanwhile, the slight reduction of NBO/T lowers the activity of O2−, resulting that the hybrid entropy of dephosphorization reaction at 1600°C being slightly greater than that at 1550°C, indicating that the dephosphorization reaction proceeds towards the reverse direction with the increase of temperature.
Get full access to this article
View all access options for this article.
References
1.
ZhouCGLiJShiCBet al.Dependence of temperature and slag composition on deophosphorization at the first deslagging in BOF steelmaking process. High Temp Mater Proc.2016;35:433–440.
2.
MaruokaNOnoSShibataHet al.Equilibrium distribution ratio of phosphorus between solid iron and magnesiowustite-saturated Al2O3-CaO-FetO-MgO-SiO2 slag at 1 623 K. ISIJ Int.2013;53:1709–1714.
3.
KitamuraSKitamuraTShibataKet al.Temperature and flux composition on hot metal dephosphorization kinetics. ISIJ Int. 1991;31:1322–1328.
4.
MukawaS.Effect of CaF2 addition, temperature, basicity and lime diameter on the rate of hot metal dephosphorization. Tetsu-to-Hagané. 2004;100:77.
5.
YeGFYangJZhangRHet al.Behavior of phosphorus enrichment in dephosphorization slag at low temperature and low basicity. Int J Miner Metall Mater. 2021;28:66–75.
6.
ZhouCGLiJWuHet al.Study on the temperature of first deslagging of double slag dephosphorization in converter. Iron Steel. 2014;49:24.
7.
WenFX. Research and application of duplex converter steelmaking dephosphorization technology. Anshan: University of Science and Technology Liaoning; 2016, 6.
8.
ZhouCGHuJZChenHet al.Dephosphorization behavior of molten steel based on high FeO converter slag. Iron Steel. 2021;56:63.
9.
ZhouCJiYChenQet al.Effect of P2O5 addition on enrichment behaviour of phosphorus in CaO–SiO2–FeO–P2O5 slag. Iron Steel. 2022. https://doi.org/10.1080/03019233.2022.2102337.
10.
LockyerMWGHollandDDupreeR.NMR investigation of the structure of some bioactive and related glasses. J Non-Cryst Solids. 1995;188:207–219.
11.
WangZSunYSeetharamanSet al.Viscous flow and crystallization behaviors of P-bearing steelmaking slags with varying fluorine content. ISIJ Int. 2016;56:546–553.
12.
DongWLPanHWLuoLet al.Phosphorous distribution in dephosphorization slag。 Iron Steel. 2020;55:75.
13.
MysenBOVirgoDScarfeCM.Relations between the anionic structure and viscosity of silicate melts - a Raman-spectroscopic study. Am Mineral. 1980;65:690.
14.
TaylorMBrownGEFennPM.Structure of mineral glasses—III. NaAlSi3O8 supercooled liquid at 805°C and the effects of thermal history. Geochim Cosmochim Ac. 1980;44:109–117.
15.
ZhangRMinYWangYet al.Structural evolution of molten slag during the early stage of basic oxygen steelmaking. ISIJ Int. 2020;60:212–219.
16.
WagnerC.The concept of the basicity of slags. Metall Trans B. 1975;6:405–409.
17.
The Japan Society for the Promotion of Science. Steelmaking data sourcebook. New York: Gordon and Breach Science; 1988.
18.
Van NiekerkWHDippenaarRJ.Phosphorus distribution between carbon-saturated iron at 1350°C and lime-based slags containing Na2O and CaF2. Metall Mater Trans B. 1998;29:147–153.
19.
MoustafaYMEl-EgiliK.Infrared spectra of sodium phosphate glasses. J Non-Cryst Solids. 1998;240:144–153.
20.
JeznachOGajcMKorzebK.New calcium-free Na2O–Al2O3–P2O5 bioactive glasses with potential applications in bone tissue engineering. J Am Ceram Soc. 2018;10:602–611.
21.
StochPGojPCiecińskaMet al.Structural features of 19Al2O3–19Fe2O3–62P2O5 glass from a theoretical and experimental point of view. J Non-Cryst Solids. 2019;521:119499.
22.
RajavaramRKimHParkJet al.Bridging between the physical properties: structure and density of CaO–SiO2–Al2O3 melts at CaO/SiO2=1.3 and different mole% of Al2O3. Ceram Int. 2019;45:19409–19414.
23.
YanWZhangGHLiJ.Viscosity and structure evolution of CaO–SiO2-based mold fluxes with involvement of CaO–Al2O3-based tundish fluxes. Ceram Int. 2020;46:14078–14089.
24.
MysenBORichetP.Silicate glasses and melts. Amsterdam: Elsevier; 2019.
25.
SilvaAMCorreiaRNOliveiraJMet al.Structural characterization of TiO2–P2O5–CaO glasses by spectroscopy. J Eur Ceram Soc. 2010;30:1253–1258.
26.
LiuCJZhangRZhaoXet al.Quantification of phosphorus structures in CaO-SiO2-P2O5 glasses via Raman spectroscopy. J Non-Cryst Solids. 2022;557:120579.
27.
WuYQJiangGCYouJLet al.Raman scattering coefficient of symmetrical tretching mode of silicate melt units. Acta Phys Sin. 2005;54:961.
28.
MatsugiRMiwaKHasegawaM.Activities of FeO and P2O5 in dephosphorization slags coexisting with solid solutions between di-calcium silicate and tri-calcium phosphate. ISIJ Int. 2017;57:1718–1724.
29.
LiJYMeiZMinGet al.Phosphate enrichment mechanism in CaO–SiO2–FeO–Fe2O3–P2O5 steelmaking slags with lower binary basicity. Int J Miner Metall Mater. 2016;23:520–533.
30.
SunHYangJZhangRet al.Influence of temperature on dephosphorization at lower basicity and lower temperature based on industrial experiments and IMCT. ISIJ Int. 2022;62:10878.
31.
ToopGSamisC.Activities of ions in silicate melts. Trans Metall Soc AIME. 1962;224:878.
