The present study was aimed at highlighting the effect of silica on chromium distribution and enrichment in certain stainless-steel slag when basicity ranged from 0.96 to 1.96. Industrial slag samples of the CaO–Al2O3–MgO–SiO2–CrOX–FeXO system were investigated with different silica addition contents and soaked at the targeted regime. X-ray diffraction, electron probe micro-analyzer with wavelength-dispersive X-ray spectrometer, as well as Fourier-transform infrared spectroscopy and NIH ImageJ software were used for sample characterisation. FactSage version 6.4 was employed to calculate phase equilibria at 1200°C for the slag system to understand the crystallisation procedure. Results indicated that chromium was enriched in CaCr2O4 at high basicity, but in spinel at lower basicity. The spinel phase increased in size and chromium distribution with Fe(II) participated in growth with the decrease in depolymerisation of the slag structure.
Get full access to this article
View all access options for this article.
References
1.
PillayKvon BlottnitzHPetersenJ.Ageing of chromium(III)-bearing slag and its relation to the atmospheric oxidation of solid chromium(III)-oxide in the presence of calcium oxide. Chemosphere. 2003;52(10):1771–1779. doi: 10.1016/S0045-6535(03)00453-3
2.
SamadaYMikiTHinoM.Prevention of chromium elution from stainless steel slag into seawater. ISIJ Int. 2011;51(5):728–732. doi: 10.2355/isijinternational.51.728
3.
MudersbachDKuehnMGeiselerJet al.Chrome immobilisation in EAF-slags from high-alloy steelmaking: tests at FEhS-Institute and development of an operational slag treatment process. Paper presented at the 1st international slag valorisation symposium; 2009; Leuven.
4.
Garcia-RamosERomero-SerranoAZeifertBet al.Immobilization of chromium in slags using MgO and Al2O3. Steel Res Int. 2008;79(5):332–339. doi: 10.1002/srin.200806135
5.
LiJLXuAJHeDFet al.Effect of FeO on the formation of spinel phases and chromium distribution in the CaO-SiO2-MgO-Al2O3-Cr2O3 system. Int J Miner Metall Mater. 2013;20(3):253–258. doi: 10.1007/s12613-013-0720-9
6.
ShuQFLuoQYWangLJet al.Effects of MnO and CaO/SiO2 mass ratio on phase formations of CaO-Al2O3-MgO-SiO2-CrOx slag at 1673K and PO2=10−10 atm. Steel Res Int. 2015;86(4):391–399. doi: 10.1002/srin.201400117
7.
AlbertssonGTengLBjorkmanBet al.Effect of low oxygen partial pressure on the chromium partition in CaO-MgO-SiO2-Cr2O3-Al2O3 synthetic slag at elevated temperatures. Steel Res Int. 2013;84(7):670–679.
8.
MillsKCLangYJonesRT.Estimating the physical properties of slags. J South Afr Inst Min Metall. 2011;111(10):649–658.
9.
ChayesF.On the bias of grain-size measurements made in thin section. J Geol. 1950;58(2):156–160. doi: 10.1086/625716
10.
HeilbronnerRBruhnD.The influence of three-dimensional grain size distributions on the rheology of polyphase rocks. J Struct Geol. 1998;20(6):695–705. doi: 10.1016/S0191-8141(98)00010-8
11.
FredericciCZanottoEDZiemathEC.Crystallization mechanism and properties of a blast furnace slag glass. J Non Cryst Solids. 2000;273(1–3):64–75. doi: 10.1016/S0022-3093(00)00145-9
12.
MerliniMGemmiMArtioliG.Thermal expansion and phase transitions in akermanite and gehlenite. Phys Chem Miner. 2005;32(3):189–196. doi: 10.1007/s00269-005-0458-7
13.
SwainsonIPDoveMTSchmahlWWet al.Neutron powder diffraction study of the akermanite-gehlenite solid solution series. Phys Chem Miner. 1992;19(3):185–195. doi: 10.1007/BF00202107
14.
ChanCJKrivenWMYoungJF.Physical stabilization of the β→γ transformation in dicalcium silicate. J Am Ceram Soc. 1992;75(6):1621–1627. doi: 10.1111/j.1151-2916.1992.tb04234.x
15.
ErikssonJBjörkmanB.Mgo modification of slag from stainless steelmaking. Paper presented at the VII international conference on molten slags, fluxes and salts; 2004; Cape Town.
16.
AlbertssonGJTengLDEngstromFet al.Effect of the heat treatment on the chromium partition in CaO-MgO-SiO2-Cr2O3 synthetic slags. Metall Mater Trans B. 2013;44(6):1586–1597. doi: 10.1007/s11663-013-9939-0
17.
AgathopoulosSTulyaganovDUVenturaJMGet al.Structural analysis and devitrification of glasses based on the CaO-MgO-SiO2 system with B2O3, Na2O, CaF2 and P2O5 additives. J Non Cryst Solids. 2006;352(4):322–328. doi: 10.1016/j.jnoncrysol.2005.12.003
18.
KimHKimWHSohnIet al.The effect of MgO on the viscosity of the CaO-SiO2-20 wt% Al2O3-MgO slag system. Steel Res Int. 2010;81(4):261–264. doi: 10.1002/srin.201000019
PuertasFTriviñoF.Examinations by infra-red spectroscopy for the polymorphs of dicalcium silicate. Cem Concr Res. 1985;15(1):127–133. doi: 10.1016/0008-8846(85)90017-1
21.
LuytASDramićaninMDAntićŽet al.Morphology, mechanical and thermal properties of composites of polypropylene and nanostructured wollastonite filler. Polym Test. 2009;28(3):348–356. doi: 10.1016/j.polymertesting.2009.01.010
22.
SmithAL.The coblentz society desk book of infrared spectra. In CarverCD, editor. The Coblentz society desk book of infrared spectra. 2nd ed. Kirkwood, MO: The Coblentz Society; 1982. pp. 1–24.
MysenBOVirgoDScarfeCM.Relations between the anionic structure and viscosity of silicate melts; a Raman spectroscopic study. Am Mineral. 1980;65(7–8):690–710.
25.
KimHSohnI.Effect of CaF2 and Li2O additives on the viscosity of CaO-SiO2-Na2O slags. ISIJ Int. 2011;51(1):1–8. doi: 10.2355/isijinternational.51.1
26.
EngstromFAdolfssonDYangQet al.Crystallization behaviour of some steelmaking slags. Steel Res Int. 2010;81(5):362–371. doi: 10.1002/srin.200900154
