DATABASE SELECTION FOR FERROUS APPLICATIONS. Database Selection for Ferrous Applications 1

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1 DATABASE SELECTION FOR FERROUS APPLICATIONS Database Selection for Ferrous Applications 1

2 Contents Topics Slide # FactSage databases for steelmaking: History and important solution phases Steelmaking chemistry and availability of database 10 Important phase diagrams for steelmaking processes 12 Slag viscosity database 33 3 Database Selection for Ferrous Applications 2

3 FactSage databases for steelmaking applications Brief History of Database Development Important Solution Phases for Steelmaking Applications Ref. : I.-H. Jung, Overview of the applications of thermodynamic databases to steelmaking processes, Calphad, 2010, vol. 34, pp Database Selection for Ferrous Applications 3

4 Databases in FactSage Brief History of FactSage Database Development 1976~2001: FACT 2001~present: FactSage (a fusion of FACT + ChemSage) < 1998 : FACT database (before 1998) 1999~2003 : FACT53 database 2000~2004 : FACT Consortium project (2000~2004): 16 companies pyrometallurgy (ferrous, non-ferrous), hydrometallurgy-corrosion, glassmaking - FACT53 database FToxid, FTmisc, FThall, FTsalt, FThelg,.. - New alloy databases: FSstel, FSlite, FScopp, SGTE,. 2004~2010 : Mini-consortiums - Al consortium (Alcoa, Alcan, and Norsk-Hydro) - Glass consortium (Corning, Schott, and Saint-Gobain) - Light alloy (Al, Mg) consortium (Al consortium, GM, MagNET): FTlite 2009~present : Mini-consortiums - Al consortium (3 companies), Glass consortium (3 companies) - Steelmaking consortium: 11 companies Consortium database ( CON1 or CON2 ) Database Selection for Ferrous Applications 4

5 Databases in FactSage for Steelmaking Applications FactPS (pure substances database): All gaseous species, stoichiometric solid and liquid species (organic, inorganic) Similar to thermodynamic tables like JANAF, Barin-Kubaschewski. (When you need a Gas phase you always have to select this database). FToxid: Frequently updated oxide database containing - many solution phases (slag, spinel, monoxide, olivine, etc.) - pure solid and liquid oxides, no gas phase FTmisc: FeLq solution - most reliable liquid steel database for steelmaking calculations (slags/refractories/gases/molten iron) FSstel: solid and liquid steel phases (also includes a small number of gases, oxides, sulfides, nitrides, etc.) - for steel solidification and alloy design. - liquid steel: reasonable calculations for steelmaking applications For steelmaking calculations: priority: FToxid > FeLq > FactPS (In the FactSage 6.4 and later versions, the best selections of compounds among multiple compound databases are provided automatically. But solutions must be selected carefully.) Database Selection for Ferrous Applications 5

6 FToxid database The four character in red Main solution phases when T > 1550 o C (steelmaking) give the name of each solution phase Slag (I option): CaO-MgO-Al 2 -SiO 2 -FeO-Fe 2 -MnO-Mn 2 -Ti 2 -TiO 2 + Gas solubility such as S (SO 2 ), P, H (OH), N, C, F, - All oxide components + sulfides: valid for liquid oxy-sulfide solution over a wide range - (Ca,Al,Mg,Si,Na//O,F): liquid oxy-fluoride valid up to ~ 50% fluoride content. Spinel (I option) (SPIN): (Mg,Fe,Mn,Co,Ni,Zn)(Al,Fe,Cr,Co,Mn,Va) 2 O 4, extensive solid solution containing MgAl 2 O 4, MgCr 2 O 4, MgFe 2 O 4, FeCr 2 O 4, Fe 3 O 4, FeAl 2 O 4, Cr 3 O 4, MnAl 2 O 4, MnCr 2 O 4, MnFe 2 O 4, etc. Al spinel (AlSp): (Fe,Mg,Mn)Al 2 O 4 -Al 2 solution a-, a -Ca2SiO4 (ac2s, bc2s): Ca 2 SiO 4 (C 2 S)-rich solution with limited solubility of Mg 2 SiO 4, Fe 2 SiO 4, Mn 2 SiO 4,etc. Olivine (Oliv): Mg 2 SiO 4, Fe 2 SiO 4, etc. (Mg,Fe,Ca,Mn,Ni,Zn,Co,Cr,etc.) 2 SiO 4, covering forsterite (Mg 2 SiO 4 ), fayalite (Fe 2 SiO 4 ), -Ca 2 SiO 4, monticellite CaMgSiO 4, tephroite Mn 2 SiO 4. Use I option specially when Ca 2 SiO 4 is present. Corundum (CORU): (Al,Cr,Fe,Mn) 2 solution, the solution of Al 2, Cr 2, Mn 2 and Fe 2. Solid miscibility gaps exist between the constituents. I option required. Monoxide (halite) (MeO_): solution of CaO-MgO-FeO-MnO-NiO-Fe 2 -Al 2 -Cr 2 etc. Major constituents: lime (CaO), periclase (MgO) and wustite (FeO). Use I option especially when CaO and MgO are present together. Database Selection for Ferrous Applications 6

7 FToxid database Mn/Ti oxides: i) ilmenite (ILME): (FeTi (ilmenite) Ti 2 MgTi MnTi + Al 2 ), ii) pseudo-brookite (PSEU): (Ti 3 O 5 FeTi 2 O 5 -MgTi 2 O 5 MnTi 2 O 5 ), iii) Ti-spinel (TiSp): (Mg,Fe,Mn)[Mg,Fe,Mn,Ti,Al] 2 O 4 iv) Rutile (TiO 2 ):TiO 2 + Ti 2 -ZrO 2 solid solution Mullite (Mull): non-stoichiometric Al 6 Si 2 O 13 with possible solubility of B. (MulF): stoichiometric Al 6 Si 2 O 13 with dilute Fe 6 Si 2 O 13. Melilite (Mel_): Ca 2 [Mg,Fe 2+,Fe 3+,Al](Fe 3+,Al,Si) 2 O 7. Akermanite Ca 2 MgSi 2 O 7 and gehlenite Ca 2 Al 2 SiO 7 form the melilite solid solution stable below 1590 C. Main additional solution phases when T < 1550 o C (solidification of slag): (Including all above phases + additional phases below) Wollastonite (Woll): (Ca,Mg,Mn)Si, which is a CaSi -rich phase stable below 1300 C. Pseudo-wollastonite is stoichiometric CaSi stable below 1550 C. Pyroxene (ppyr, opyr, cpyr): (Mg,Ca,Fe)[Mg,Fe]Si 2 O 6, which is a MgSi -rich phase stable below 1560 C. Proto-, ortho-, low-clino-pyroxene exist. Clino-pyroxene is a CaMg 2 SiO 6 -rich phase, which is stable below 1390 C. Rhodonite (Rhod): (Mn,Ca)Si, a MnSi -rich solid stable below 1300 C. Database Selection for Ferrous Applications 7

8 FToxid database Main additional solution phases in the CaO-Al 2 -SiO 2 -Fe t O system at high PO 2 (air) CAFS Ca 2 (Al,Fe) 8 SiO 16, CAF6 Ca(Al, Fe) 12 O 19, CAF3 Ca(Al,Fe) 6 O 10, CAF2 Ca(Al,Fe) 4 O 7 CAF1 Ca(Al,Fe) 2 O 4, C2AF Ca 2 (Al,Fe) 2 O 5, C3AF Ca 3 (Al,Fe) 2 O 6 Main additional solution phases when T < 1550 o C (mould flux, Na 2 O-containing systems) Nepheline (Neph): NaAlSiO 4 with excess SiO 2. Carnegeite (Carn): NaAlSiO 4 with excess SiO 2. NaAlO2 (NASl): low temperature - NaAlO 2 with excess NaAlSiO 4 NaAlO2 (NASh): high temperature - NaAlO 2 with excess NaAlSiO 4 Combeite (NCSO): Na 4 CaSi 3 O 9 (bombeite) Na 2 Ca 2 Si 3 O 9 solid solution Feldspar (Feld): complete solution between Anorthite(CaAl 2 Si 2 O 8 )-Albite(NaAlSi 3 O 8 ) NCA2: (Na 2,Ca)O Na 2 O 2Al 2 solid solution C3A1: Ca 3 Al 2 O 6 dissolving Na 2 O, (Ca,Na 2 )1Ca 8 Al 6 O 18 solution Database Selection for Ferrous Applications 8

9 FTmisc (FeLq) and FSstel FeLq Liquid Fe containing Ag,Al,B,Ba,C,Ca,Ce,Co,Cr,Cu,H,Hf,La,Mg,Mn,Mo,N,Nb,Nd,Ni,O,P,Pb,Pd,S,Si, Sn,Ta,Th,Ti,U,V,W,Zr. This phase is better suited for calculations involving iron and steelmaking processes (optimized for iron-rich solutions only). Based on the Unified Interaction Parameter Formalism (more advanced than classical Wagner Interaction Parameter Formalism) with associate model for deoxidation. Many interaction parameters between metallic elements are taken from JSPS (Japanese compilation) FSstel database FCC/BCC: Fe / Carbide / Nitride are all treated as FCC phases Fe with N and C : use J option (possible 3-phase immiscibility). Fe with N or C : use I option (possible 2-phase immiscibility). Also recommend to use I option for BCC phase See Fe-Ti-Nb-C-N example. Liquid: O and S are treated by the associate model FCC ordered phase (FCC_L12), BCC ordered phase (BCC_B2) normally slow down the calculations significantly. If you are not really interested in order/disorder transitions, do not select these phases. Carbon: when C content is lower than ~ 1%, Fe 3 C (metastable) phase is normally formed instead of C (stable). So, in the selection of solid phases, deselect C solid. Database Selection for Ferrous Applications 9

10 Steelmaking Chemistry and Availability of Databases The important chemical systems of non-metallic phases for steelmaking processes can be summarized as follows. All of these are modeled in the FactSage databases. Database availability for general steelmaking processes: Blue: available in FactSage 6.4; Green: available in 7.0; Red: unavailable 1) Molten slag for refining processes a) CaO-FeO-Fe 2 -SiO 2 -MgO-MnO-P 2 O 5 system: BOF process b) CaO-MgO-Al 2 -SiO 2 -FeO-Fe 2 system: ladle refining process c) CaO-MgO-SiO 2 -CaF 2 system: stainless steel refining d) CaO-CrO-Cr 2 -MgO-SiO 2 system: AOD and VOD process for stainless steel e) CaO-MgO-SiO 2 -MnO-CrO-Cr 2 system: high-mn stainless steel 2) Mould flux for casting processes a) CaO-MgO-Al 2 -SiO 2 -Na 2 O(-Li 2 O)-F system: conventional process b) CaO-MgO-Al 2 -SiO 2 -Na 2 O-Li 2 O-B 2 system: new candidate. Database Selection for Ferrous Applications 10

11 3) Non-metallic inclusions a) CaO-Al 2 -MgO-CaS: conventional low carbon steels b) MnO-SiO 2 -Al 2 -CaO-MnS: wire steels and free cutting steels c) MnO-SiO 2 -Ti 2 -TiO 2 -Al 2 : high strength steels d) Al 2 -Ti 2 -TiO 2 : interstitial-free (IF) steels e) Ti-Nb-C-N: high-strength low-alloy (HSLA) steels containing Ti and Nb 4) Refractories a) MgO-C: BOF and RH vessel refractories, ladle slag line b) MgO-Al 2 : ladle castable c) MgO-Cr 2 -FeO-Fe 2 -Al 2 : VOD and AOD refractories d) Al 2 -ZrO 2 -SiO 2 -C: nozzle refractories and tundish plugs Database Selection for Ferrous Applications 11

12 Most common phase diagrams for steelmaking applications CaO-MgO-SiO 2 -Al 2 -FeO-Fe 2 -MnO Na 2 O-CaO-Al 2 -SiO 2 MnO-Ti 2 -TiO 2 Database Selection for Ferrous Applications 12

13 Temperature, o C Important phases and phase diagrams Temperature, o C 3000 Monoxide; halite solution (MeO_) Fe(liquid)+MW+Slag Fetters and Chipman[71] Schenck and Pfaff[54] Gokcen[69] Fischer and Ende[72] Taylor and Chipman[70] Shim and Ban-Ya[74] Scheel et al.[73] Fe(liquid)+Slag Fe(liquid)+MW Fe(bcc) + MW Fe(fcc) + MW molar ratio FeO/(MgO+FeO) Lime + Slag Zhao et al.[45] Abbatista[20] Allen and Snow[17] Larson[21] Takeda[22] Timucin[23] Slag 1371 o C 1200 Lime o C o C Lime+Wustite Wustite Lime + Ca 2 Fe 2 O 5 Ca 2 Fe 2 O 5 Ca 2 Fe 2 O 5 + Wustite mass FeO/(CaO+FeO) Database Selection for Ferrous Applications 13

14 Important phases and phase diagrams Temperature ( o C) Olivine: M 2 SiO 4 MgSi -rich: pyroxene MnSiO3-rich: rhodonite o C 2 Liquids Liquid 1702 o C SiO 2 (Crist) 1500 MnO 1465 o C 1400 SiO 2 (Trid) 1347 o C 1328 o C o C 0.43 Mn 2 SiO 4 MnSi 1251 o C mole fraction MnO Database Selection for Ferrous Applications 14

15 Temperature, o C Monoxide Temperature, o C Temperature ( o C) Temperature ( o C) o C 1890 o C 1890 o C Al 2 Mullite (Al 6 Si 2 O 13 ) Important phases and phase diagrams Liquid 1596 o C o C mole fraction SiO 2 Mullite SiO 2 (Crist) SiO 2 (Trid) 1723 o C o C Al o C MnAl 2 O mole fraction MnO Jacob[16] Olsen & Heynert[17] 1527 o C 0.77 MnO 1842 o C Rankin and Merwin[21] Viechnicki et al[23] Alper et al[22] Saalfeld and Jagodzinski[32] Viertel and Seifert[30] (1985, 0.36) Shirasuka and Yamaguchi[29] Henriksen and Kingery[27] Whitney and Stubican[28] Liquid 2122 Spinel Mori[24] Stubican and Roy[25] Frenkel et al[26] Roy et al[31] Lejus[33] (1994, 0.79) (2008, 0.92) MgO mole fraction Al 2 Spinel: A 2+ (B 3+ ) 2 O 4 Al MW Roberts and Merwin[66]: phase boundaries Woodhouse and White[39]: monoxide boundary Willshee and White[65]: invariant points Schurmann and Kolm[68]: Slag MW + Spinel MW + Slag 1711 Slag Spinel Phillips et al.[67] Slag MW+Slag Slag+Solid MW MW+Spinel Spinel Spinel + Fe molar ratio Fe 2 /(MgO+Fe 2 ) Database Selection for Ferrous Applications 15

16 Important phases and phase diagrams Database Selection for Ferrous Applications 16

17 T(C) Important phases and phase diagrams Mg 2 SiO 4 - Fe 2 SiO 4 - Fe Fe/(Mg 2 SiO 4 +Fe 2 SiO 4 ) (mol/mol) = ASlag-liq Fe saturation ASlag-liq + AOlivine Fe(liq) Fe(s) Fe(s) Fe(s2) 1200 AOlivine Fe 2 SiO 4 /(Mg 2 SiO 4 +Fe 2 SiO 4 ) (mol/mol) Database Selection for Ferrous Applications 17

18 Important phases and phase diagrams Database Selection for Ferrous Applications 18

19 Important phases and phase diagrams MgO (2825) SiO 2 (1723) 2600 SiO 2 (Trid) Two-Liquids 1600 SiO 2 (Crist) MgSi Cordierite (Mg 2 Al 4 Si 5 O 18 ) MgO CaMg 2 Al 16 O 27 Ca 3 MgAl 4 O Mg 2 SiO Sapphirine (Mg 4 Al 10 Si 2 O 23 ) Mullite 1800 Spinel Ca 2 Mg 2 Al 28 O SiO 2 (1723) Al CaO CaAl 2 O 4 CaAl O 7 Al (1604) 1597 (1765) CaO Ca 3 Al 2 O 6 CaAl 12 O 19 (2572) (2054) 1400 Mole fraction Al 2 2 Liquids MgO Spinel MgO weight percent Al 2 (2825) (2054) MnSi Rhodonite Cristobalite Tridymite Mullite Mn 2 Al 4 Si 5 O 18 (Mn-Cordierite) (1180) Mn 3 Al 2 Si 3 O 12 (Spessartite) (1200) Mn 2 SiO 4 Tephroite 1156 (1347) MnO Galaxite Corundum Al 6 Si 2 O 13 (1890) 1890 MnO (1842) 1527 weight percent 1769 MnAl 2 O 4 (2054) Database Selection for Ferrous Applications 19 Al 2

20 Important phases and phase diagrams Database Selection for Ferrous Applications 20

21 Important phases and phase diagrams T( o C) Coru solution Spinel solution System Ca 2 Al 2 SiO 7 - Ca 2 MgSi 2 O [41] Osborn and Schairer Liquid Liquid + Mel Mel [22] Buddington : rxn time not enough Liquid Liquid + rare mel mel + rare L Melilite solid solution 1500 Liquid 1400 L+Merw (75, 1390 o C) Geh-Aker (melilite solution) wt% Ca 2 MgSi 2 O 7 /(Ca 2 Al 2 SiO 7 +Ca 2 MgSi 2 O 7 ) Database Selection for Ferrous Applications 21

22 Important phases and phase diagrams Pseudo-brookite Ti-spinel ilmenite Database Selection for Ferrous Applications 22

23 Important phases and phase diagrams Database Selection for Ferrous Applications 23

24 T(C) Na 2 O-containing system: Na 2 O-SiO 2 -CaO-Al 2 CaAl 2 Si 2 O 8 - NaAlSi 3 O 83 Weill et al. (1980), compliation C: CaO A: Al 2 N: Na 2 O S: SiO 2 CA CaO C 2 AS C 2 S Feldspar Slag CS mole NaAlSi 3 O 8 /(CaAl 2 Si 2 O 8 +NaAlSi 3 O 8 ) CAS 2 Al 2 NA 6 NA Na 2 O NAS NAS 6 2 NS SiO 2 * Most recently updated version: CON1 database Database Selection for Ferrous Applications 24

25 Temperature (K) Important phases and phase diagrams: Na 2 O-Al 2 -SiO 2 system T(C) NaAl 9 O 14 (s) + Al 2 (s4) Rys (2008): DTA-TG, heating Rys (2008): DTA-TG, cooling Na 10 SiO 7 Na 4 SiO 4 Na 6 Si 2 O 7 Na 2 Si Na 2 Si 2 O 5 Na 6 Si 8 O Na 2O - Al Na 2 O mole fraction SiO 2 ASlag-liq ASlag-liq + NaAl 9 O 14 (s) ASlag-liq + NaAlO 2 (s2) NaAlO 2 (s2) + NaAl 9 O 14 (s) 1100 Na 2 O(s3) + NaAlO 2 (s2) 900 Na 2 O(s2) + NaAlO 2 (s2) NaAlO 2 (s2) + Na 2 Al 12 O 19 (s) 700 Na 2 O(s) + NaAlO 2 (s2) Al 2 /(Na 2 O+Al 2 ) (mol/mol) Database Selection for Ferrous Applications 25

26 Important phases and phase diagrams: Na 2 O-Al 2 -SiO 2 system Carg NASh Neph NASl Database Selection for Ferrous Applications 26

27 Important phases and phase diagrams: Na 2 O-CaO-SiO 2 system T(C) CaSi - Na 2 Si NCSO: 1:2:3 solid solution SiO 2 - CaO - Na 2 O Moir and Glasser (1974) (1:2:3) (1:2:3) + (2:1:3) (1:2:3) + bcs L + (1:2:3) (2:1:3) L + (2:1:3) (2:1:3) + NS acs acs + (1:2:3) acs + bcs + (1:2:3) L + acs bcs + (1:2:3) acs + bcs L L + NS (1:2:3)' - maybe (1:1:2) (1:2:3)' + NS (1:2:3) + (2:1:3) + NS Slag Slag + CaSiO3(s2) 1:2:3 + CaSiO3(s2) SiO Na2SiO3(s) + Na4CaSi3O9(s) 1:2:3 (a:b:c) = ana 2 O.bCaO.cSiO 2 Morey and Bowen (1925) (0:1:1) (0:0:1) - Tr. (0:0:1) - Cr. (0:3:2) (1:2:3) (1:3:6) (1:0:2) Na 2 O (0:0:1) - Qz. (3:0:2) (2:0:1) (1:0:1) (1:0:2) (1:3:6) (4:3:5) (0:1:1) (2:1:3) (1:2:3) (4:3:5) (1:2:2) (0:3:2) (1:1:1) (0:2:1) Weight % Segnit (1953) (2:1:3) (1:1:1) (1:0:1) (1:1:5) (1:0:1) (3:0:8) (2:1:3) (0:2:1) 1000 o C 1100 o C 1200 o C Shahid and Glasser (1971) (1:1:5) (3:0:8) (5:0:1) (1:0:2) (0:0:1) - Qz. (1:2:3) (0:0:1) - Tr. (1:3:6) 1100 o C 1300 o C 1400 o C 1500 o C (1:2:3) (0:1:1) (1:2:2) (0:4:1) CaO 600 1:2:3 + CaSiO3(s) 1:2:3 + Na2SiO3(s) (a:b:c) = ana 2 O.bCaO.cSiO CaO-Na 2 O-SiO 2 mole CaSi /(CaSi +Na 2 Si ) SiO 2 (3:0:8) (1:1:5) (1:0:2) (1:3:6) (1:0:1) (2:1:3) (1:2:3) (3:0:2) (4:3:5) (2:0:1) (1:2:2) (1:1:1) (5:0:1) (0:1:1)? (0:3:2) (0:2:1) (0:4:1) FactSag Na 2 O mole fraction Database Selection for Ferrous Applications CaO

28 Important phases and phase diagrams: Na 2 O-Al 2 -CaO system (a:b:c) = ana 2 O.bCaO.cAl Na 2 O (1:8:3) (1:0:9) (0:3:1) Na 2 O - Al 2 - CaO CaO(s) Projection (Slag) CaAl 2 O 4 (s) CaAl 4 O 7 (s) Al 2 (s4) (0:1:1) (0:1:2) (0:1:6) CaO Al 2 mole fraction NaAlO 2 (s2) (1:0:1) 1:1:2 NaAl 9 O 14 (s) N(a)C(b)A(c) = ana 2 O.bCaO.cAl 2 Slag (1:0:6) FactSage NC8A C3A Na 2 O - Al 2 - CaO 1200 o C Na 2 O CA CA2 CA CaO Al 2 mole fraction NCA2 s.s Database Selection for Ferrous Applications 28 Verweij and Saris (1986), maximum solubility NA NC3A8 NA6 NA9 FactSage NCA2: (Na 2,Ca)O Na 2 O 2Al 2 solid solution

29 Important phases and phase diagrams: Na 2 O-Al 2 -SiO 2 -CaO system CaO D:\Work\CRCT\2007_MoldFlux_POSCO\Na2O-CaO-SiO2-Al2O3\quaternary_parameter\PD_CaSiO3-Ca2Al2SiO7-NaAlSiO4.emf 10/25/2008 Al 2 Juan (1950) Ca 2 Al 2 SiO 7 T(min) = o C, T(max) = o C Na 2 O SiO 2 MEL Cg Ne PW Ca 3 Si 2 O 7 (s) CaSi (s2) Melilite Nepheline Carnegieite CaSi NaAlSiO 4 mass fraction Database Selection for Ferrous Applications 29

30 Important phases and phase diagrams: Na 2 O-Al 2 -SiO 2 -CaO system CaO D:\Work\CRCT\2007_MoldFlux_POSCO\Na2O-CaO-SiO2-Al2O3\quaternary_parameter\PD_CaSiO3-CaAl2Si2O8-NaAlSiO4.emf 10/25/2008 Al 2 Gummer (1943) CaAl 2 Si 2 O 8 T(min) = o C, T(max) = 1555 o C Na 2 O SiO 2 CA2S2 Cg Ne C3A PW C2AS2 b-a CaSi (s2) Melilite Feldspar Carnegieite CaSi NaAlSiO 4 mass fraction Database Selection for Ferrous Applications 30

31 Important phases and phase diagrams: Na 2 O-Al 2 -SiO 2 -CaO system CaO D:\Work\CRCT\2007_MoldFlux_POSCO\Na2O-CaO-SiO2-Al2O3\quaternary_parameter\PD_NaAlSiO4-CaSiO3-Na2SiO3.emf 10/25/2008 Al 2 Spivak (#1342) NaAlSiO 4 T(min) = o C, T(max) = o C Na 2 O SiO 2 1:2:3 2:1:3 Cg Ne PW NS W CaSi (s2) Carnegieite Nepheline 1:2: Na 2 Si (s) 2:1: CaSi Na 2 Si mass fraction Database Selection for Ferrous Applications 31

32 Important phases and phase diagrams: Na 2 O-Al 2 -SiO 2 -CaO system CaO SiO 2 - CaO - Na 2 O - Al 2 15wt% Al 2 section Al 2 SiO 2 Al 6 Si 2 O 13 (s) T(min) = o C, T(max) = o C Na 2 O SiO 2 CaO(s) NaAlO2-NaAlSiO Feldspar Nepheline Na 2 Ca 3 Si 6 O 16 (s) NaAlO2-NaAlSiO4 NaAlO2-NaAlSiO41 CaSi (s2) 1:2: Feldspar Ca 3 Si 2 O 7 (s) Melilite Ca 2 SiO 4 (s2) 1:1:2 Ca 2 SiO 4 (s3) 1400 Na 2 O mass fractions /(SiO 2 +CaO+Na 2 O) CaO Database Selection for Ferrous Applications 32

33 Slag Viscosity: Structural Viscosity Model Modified Quasichemical Model Bond fraction (Silicate network structure) Activation energy of bond breaking reaction: Binary parameters + Association energy for M + Al 3+ replacing Si 4+ in silicate network Prediction of multicomponent systems (oxide and oxyfluoride) Heterogeneous (solid + liquid): Einstein-Rosco equation Database for molten slag CaO-MgO-SiO 2 -Al 2 -FeO-Fe 2 -MnO-TiO-TiO 2 -Na 2 O-K 2 O- B 2 -F (-PbO-NiO) Database for glass (supercooled melt) CaO-MgO-SiO 2 -Al 2 -Na 2 O-K 2 O-B 2 -PbO- Database Selection for Ferrous Applications 33

34 The Na 2 O-Al 2 -SiO 2 system ln(visc) [PaS] Fig. 16 Fig SiO mole fraction T = 1400 C Riebling, 1966 Fig. 20 Toplis et al., 1997 Fig. 19 Fig Na 2 O Al C mole fraction SiO 2 = 0.5 Toplis et al Riebling, 1966 below liquidus C C 1600 C molar ratio Al 2 / (Al 2 +Na 2 O) Database Selection for Ferrous Applications 34

35 The Na 2 O-Al 2 -SiO 2 system ln(visc) [PaS] Fig. 16 Fig SiO mole fraction T = 1400 C Riebling, 1966 Fig. 20 Toplis et al., 1997 Fig. 19 Fig Na 2 O Al C mole fraction SiO 2 = 0.67 Toplis et al Stein and Spera, 1993 Riebling, 1966 Kim and Lee, below liquidus C C 1600 C molar ratio Al 2 / (Al 2 +Na 2 O) Database Selection for Ferrous Applications 35

36 ln (Pa s) Viscosity of CaO-Al 2 -SiO 2 -R 2 O (R=K, Na, Li) 1 0 T = 1600 o C Addition of K 2 O Addition of Na 2 O Addition of Li 2 O , Sukenaga et al. Addition of K 2 O Na 2 O Li 2 O Initial Composition (wt.%) 32CaO-48SiO 2-20Al 2 40CaO-40SiO 2-20Al 2 44CaO-36SiO 2-20Al Mole fraction of alkali oxide R 2 O Database Selection for Ferrous Applications 36

37 12 Viscosities of various systems ln [Pa s], Experimental Al 2 -SiO 2 10 CaO-Al 2 8 CaO-SiO 2 18 MgO-SiO CaO-MgO-SiO 2 K 2 O-SiO CaO-Na O-SiO 2 4 Na 2 O-SiO Na O-Al7 2 -SiO 2 CaO-Al 2 -MgO-SiO 2 2 CaO-Al 2 -SiO CaO-Al 2 -Na 2 O-MgO-SiO 2 MgO-Al 2 -SiO ln [Pa s], -2 0 Calculated ln [Pa s], Calculated ln [Pa s], Experimental ln [Pa s], Experimental ln [Pa s], Calculated Database Selection for Ferrous Applications 37