GTT Annual Workshop, July 3-5, 2013 Incorporation of O 5 into the oxide core database with Al, Si, Ca and Mg 4. Juli 2013 Elena Yazhenskikh 1, Klaus Hack 2, Tatjana Jantzen 2, Michael Müller 1 1 Forschungszentrum Jülich, IEK-2 (Microstructure and properties of materials), Germany 2 GTT-Technologies, Herzogenrath, Germany
Contents Motivation and aim of the work Models, optimisation, phases under consideration The binary systems with O 5 : O 5 -CaO, O 5 -MgO systems O 5 -Al 2 O 3 system O 5 -SiO 2 system The ternary systems with O 5 O 5 -Al 2 O 3 -CaO O 5 -SiO 2 -Al 2 O 3 O 5 -SiO 2 -MgO O 5 -SiO 2 -CaO Modelling of α-ca 2 SiO 4 Modelling of α -Ca 2 SiO 4 Conclusions and outlook 2
Motivation and aim of work O 5 is an essential component for the co-gasification of phytogenic and zoogenic biomass. The addition of O 5 improves the fluidity of molten slags. The phosphates are of interest in connection with soil-fertilizer relationships. The dephosphorization is important in the iron and steel industry. O 5 State of the art: 2-, 3- and multicomponent systems have been thermodynamically assessed using all available experimental data phase diagrams and other thermodynamic properties can be calculated with the obtained self-consistent datasets MgO Al 2 O 3 SiO 2 CaO Aim of our work: development of a new data base, which is applicable for the slag relevant system containing oxides of Si, Al, Na, K, Ca, Mg, Fe, P, S, Cr etc. and suitable for the calculations and/or predictions of the phase equilibria and other thermodynamic properties by variation of T and composition 20. Dezember 2013 GTT Annual Workshop, Juli 3-5, 2013 3
Database development Experimental data from literature source and from our measurements: phase diagram data, activity data etc. Choice of the suitable model Initial data for pure substances, liquid and solid solution components OptiSage in Adjustable parameters: ΔH 298 f and S 298 for the liquid and solid solution species ΔH 298 f and S 298 for the pure solid compounds Interaction parameters between species optimisation Liquid: non-ideal associate solution using Redlich-Kister-Muggianu equation G x G RT x lnx x x L (x x )... 0 (v) m i i i i i j ij i j i j v 0 Solids: compounds v Comparison of the results with exp. data agreement G = A + B*T + C T*ln(T) + D*T 2 + E*T 3 + F/T Solid solutions: sublattice approach (CEF) n n s 0 ( ) s ( ) s ( ) ln( ) ( ) ( ).. m I0 I 0 s i i 1 I 1 I I2 I2 s 1 i 1 0 1 2 G P Y G a RT y y P Y L P Y L I I I New dataset 4
Modelling of binary O 5 -containing phases The species in the non-ideal associate solution containing O 5 were added in order to describe the liquid phase. Binary solid phases were considered as compounds System Associate species in liquid Me x O y : O 5 CaO- O 5 3:1, 2:1, 1:1 Ca 3 O 8, Ca 2 O 7, Ca O 8 [Serena 2011] MgO - O 5 3:1, 2:1, 1:1 Mg 3 O 8 (SGPS), Mg 2 O 7, Mg O 8 Solid phase CaO. 2 O 5 2CaO. 3 O 5 CaO. O 5 2CaO. O 5 (s1,s2,s3) 3CaO. O 5 (s1,s2,s3) 4CaO. O 5 MgO. O 5 2MgO. O 5 3MgO. O 5 Description of solid phase Al 2 O 3 - O 5 1:1 AlPO 4 (SGPS) 3Al 2 O 3. O 5 AlPO 4 (s3,s2,s1) Al 2 O 3. 3 O 5 SiO 2 - O 5 1:1 SiO. 2 O 5 Si O 7 5SiO 2. 3 O 5 5
Mg 2 O 7 (s) MgO 6 (s) T(C) Ca 4 (PO 4 ) 2 O T(C) CaO- O 5 and MgO- O 5 CaO - O 5 1 bar 2800 2500 [Hill, 1944] [Trömmel, 1961, DTA] [Trömmel, 1961, hot stage microscope] 2200 1900 1600 Slag MeO + Slag J. Berak, Rocz. Chem., 32 [1], (1958), pp.17-22. 1300 MeO + Ca 4 (PO 4 ) 2 O(s) 1000 700 400 O 5 CaP 4 O 11 Ca 2 P 6 O 17 Ca(PO 3 ) 2 Ca 2 O 7 Ca 3 (PO 4 ) 2 100 0 0.2 0.4 0.6 0.8 1 CaO/(CaO+ O 5 ) (g/g) 2700 2400 MgO - O 5 1 atm [J. Berak, 1958] 2100 Slag W. L. Hill, G. T. Faust, and D. S. Reynolds, Am. J. Sci., 242 [9] 457-477 (1944); G. Troemel, Stahl Eisen, 63 [2] 21-30 (1943). 1800 MeO + Slag 1500 1200 900 MeO + Mg 3 O 8 (s) 600 Mg 3 O 8 MgO 6 (s) + O 5 (s2) 300 0 0.2 0.4 0.6 0.8 1 O 5 /(MgO+ O 5 ) (g/g) 6
AlP 3 O 9 (s) T(C) Al 3 PO 7 (s) Al 2 O 3 - O 5 2700 2500 2300 [Stone, Egan, 1956] Al 2 O 3 - O 5 1 bar [Tananaev, Maksimchuk, 1978] 2100 Slag 1900 1700 1500 P.E. Stone, E.P. Egan, J.R. Lehr, J. Am, Ceram. Soc., 39 [3], (1956), pp.89-98. 1300 1100 900 Al 2 O 3 (s) + Al 3 PO 7 (s) AlPO 4 (s3) 700 500 300 100 AlPO 4 (s2) AlPO 4 (s) AlP 3 O 9 (s) + O 5 (s2) 0 0.2 0.4 0.6 0.8 1 O 5 /(Al 2 O 3 + O 5 ) (g/g) I.V. Tananaev, E.V. Maksimchuk,Y. G. Bushuev, S.A. Shestov, Izv. Akad. Nauk SSSR, Neorg. Mater., 14 [4], (1978), pp.719-722. 7
SiO 2 - O 5 : experimental data There is not enough experimental data on phase diagrams and compounds. The few data available is contradictory. Hence, experimental studies are needed. T. Y. Tien and F. A. Hummel, J. Am. Ceram. Soc.,45 [9] 422-424 (1962). G. Baret, R. Madar, and C. Bernard, J. Electrochem. Soc., 138 [9] 2830-2835 (1991). A. E. Mal'shikov and I. A. Bondar, Russ. J. Inorg. Chem. (Engl. Transl.), 33[1] 109-112 (1988). 8
ln y Si 5 P 6 O 25 (s) + Si O 7 (s) T(C) excess H, J/mol SiO 2 - O 5 : calculation 3500 SP25+Baret, excess H 3000 1800 1600 1400 1200 1000 800 600 Liq+SiO2 Slag assumed eut line SiO 2 (s2) + Si 5 P 6 O 25 (s) glass+crist [Tien, 1962] glass+s2p [Tien, 1962] S2P [Tien, 1962] glass +high SP [Tien, 1962] high SP+S2P [Tien, 1962] low SP [Tien, 1962] high SP [Tien, 1962] glass [Tien, 1962] Liq+S3P2 Slag + Si 5 P 6 O 25 (s) Si 5 P 6 O 25 SiO 2 (s) + Si 5 P 6 O 25 (s) Liq+SP SiO 2 - O 5 1 atm glass+crist [Malshikov 1988,1989] glass+s5p3 [Malshikov 1988,1989] glass+sp [Malshikov 1988,1989] Tinv+Tm SP [Malshikov 1988,1989] 2-phase field [Baret 1991] In the present work, the compound 5SiO 2. 3 O 5 (Tm, XRD data) has been taken into account Si O 7 Slag + Si O 7 (s3) Slag + Si O 7 (s2) Slag + Si O 7 (s) Si O 7 (s) + O 5 (s2) 400 0 0.2 0.4 0.6 0.8 1 O 5 /(SiO 2 + O 5 ) (mol/mol) 2500 2000 1500 1000 500 exp, evaluated calculated, set 25 0 0.00 0.20 0.40 0.60 0.80 1.00 0.2 0.15 0.1 0.05 0-0.05-0.1-0.15 mole /5 O Activity coefficient in SiO 2 -PO 2.5, 1550 C exp, evaluated calculated, set 25-0.2 0.85 0.9 0.95 1 mole SiO 2 9
Modelling of ternary O 5 -containing phases In all ternary systems there are no ternary species, with the exception of the system Al 2 O 3 -MgO- O 5, where one ternary species Al 2 O 3. 3MgO. O 5 was incorporated System* Solid phase Description of solid phase Al 2 O 3 -SiO 2 - O 5 CaO-SiO 2 - O 5 CaO-MgO- O 5 AlPO 4 _MT AlPO 4 _HT SiO 2 _HT SiO 2 _MT Al 2 O 3. 4SiO 2. 3 O 5 (no data) Ca 2 SiO 4 -alpha =Ca 3 O 8 -alpha prime Ca 2 SiO 4 -alpha-prime 7CaO. O 5. 2SiO 2 5CaO. O 5. SiO 2 C3P- beta C3P-alpha C3P-alpha-prime M3P C2P-MT M2P C3M3P2 CMP (Al 3+, Si 4+ )(P 5+, Si 4+ )(O 2- ) 4 (Al 3+, Si 4+ )(P 5+, Si 4+ )(O 2- ) 4 (Al 3+, Si 4+ )(P 5+, Si 4+ )(O 2- ) 4 (Al 3+, Si 4+ )(P 5+, Si 4+ )(O 2- ) 4 Stoichiometric (Ca 2+ ) 3 (Ca 2+,Va) 1 (P 5+,Si +4 ) 2 (O 2- ) 8 (Ca 2+ ) 3 (Ca 2+,Va) 1 (P 5+,Si +4 ) 2 (O 2- ) 8 Stoichiometric Stoichiometric (Ca 2+,Mg 2+ ) 3 (P 5+ ) 2 (O 2- ) 8 (Ca 2+,Mg 2+ ) 3 (P 5+ ) 2 (O 2- ) 8 (Ca 2+,Mg 2+ ) 3 (P 5+ ) 2 (O 2- ) 8 (Ca 2+,Mg 2+ ) 3 (P 5+ ) 2 (O 2- ) 8 (Ca 2+,Mg 2+ ) 2 (P 5+ ) 2 (O 2- ) 7 (Ca 2+,Mg 2+ ) 2 (P 5+ ) 2 (O 2- ) 7 (Ca 2+,Mg 2+ ) 3 (Mg 2+ ) 3 (P 5+ ) 4 (O 2- ) 16 (Ca 2+,Mg 2+ ) 1 (Ca 2+ ) 1 (P 5+ ) 2 (O 2- ) 7 *All other systems do not have ternary compound or phases 10
T(C) T(C) T(C) T(C) CaO-Al 2 O 3 - O 5 : isoplethal sections 2400 2200 2000 Al 2 O 8 - Ca 2 O 7 1 atm Slag [Stone, Egan and.lehr,1956] 1700 1500 [Stone, Egan and Lehr,1956] Al 2 P 6 O 18 - Ca O 6 1 atm Slag 1800 1600 Slag + AlPO 4 (s3) 1300 1400 1200 1000 AlPO 4 (s3) + Ca 2 O 7 (s3) AlPO 4 (s3) + Ca 2 O 7 (s2) Slag + Ca 2O 7(s3) 1100 900 Slag + Al 2 P 6 O 18 (s) Slag + Ca(PO 3 ) 2 (s) 800 600 400 AlPO 4(s3) + Ca 2O 7(s) AlPO 4(s2) + Ca 2O 7(s) AlPO 4(s) + Ca 2O 7(s) AlPO 4 (s) + Ca 2 O 7 (s) 200 0 0.2 0.4 0.6 0.8 1 Ca 2 O 7 /(Al 2 O 8 +Ca 2 O 7 ) (g/g) 700 Al 2 P 6 O 18 (s) + Ca(PO 3 ) 2 (s) AlPO 4 (s) + Al 2 P 6 O 18 (s) + Ca 2 P 6 O 17 (s) AlPO 4(s) + Ca(PO 3) 2(s) + Ca 500 2P 6O 17(s) 0 0.2 0.4 0.6 0.8 1 Ca O 6 /(Al 2 P 6 O 18 +Ca O 6 ) (g/g) Al 2 O 8 - Ca 3 O 8 Al 2 P 6 O 18 - Ca 2 O 7 2400 [Stone, Egan and Lehr, 1956] 1700 [Stone, Egan and Lehr, 1956] 2200 2000 1800 1600 1400 1200 1000 800 600 400 Slag Slag + AlPO 4 (s3) Slag + Ca 3(PO 4) 2(s3) Slag + Ca 3(PO 4) 2(s2) AlPO 4 (s3) + Ca 3 (PO 4 ) 2 (s2) AlPO 4 (s3) + Ca 3 (PO 4 ) 2 (s) AlPO 4 (s2) + Ca 3 (PO 4 ) 2 (s) AlPO 4 (s) + Ca 3 (PO 4 ) 2 (s) 200 0 0.2 0.4 0.6 0.8 1 Ca 3 O 8 /(Al 2 O 8 +Ca 3 O 8 ) (g/g) 1500 Slag 1300 Slag + Ca 2O 7(s3) Slag + AlPO 4(s3) + Ca 2O 7(s3) 1100 Slag + AlPO 4 (s3) Slag + Al 2P 6O 18(s) Slag + AlPO 4(s3) + Ca 2O 7(s2) 900 Slag + AlPO 4(s3) + Al 2P 6O 18(s) AlPO 4(s3) + Ca(PO 3) 2(s2) + Ca 2O 7(s) AlPO 4 (s3) + Al 2 P 6 O 18 (s) + Ca(PO 3 ) 2 (s) 700 AlPO 4(s2) + Ca(PO 3) 2(s) + Ca 2O 7(s) 500 AlPO 4(s) + Al 2P 6O 18(s) + Ca 2P 6O 17(s) AlPO 4(s) + Ca(PO 3) 2(s) + Ca 2O 7(s) AlPO 4(s)+P 6Al 2O 18(s)+CaP 4O 11(s) AlPO 300 4(s)+Ca(PO 3) 2(s)+Ca 2P 6O 17(s) 0 0.2 0.4 0.6 0.8 1 Ca 2 O 7 /(Al 2 P 6 O 18 +Ca 2 O 7 ) (g/g) 11
CaO-Al 2 O 3 - O 5 : liquidus surface P. E. Stone, E. P. Egan, Jr., and J. R. Lehr, J. Am. Ceram. Soc., 39 [10], (1956), pp. 361-362. 12
Modelling of AlPO 4 -SiO 2 phases Solid solubility of AlPO 4 in SiO 2 and SiO 2 in AlPO 4 for 2 crystalline modifications on the each side is described using the formula (Al 3+, Si 4+ )(P 5+, Si 4+ )(O 2- ) 4 Si 4+ :Si 4+ Al 3+ :Si 4+ Si 4+ :P 5+ Al 3+ :P 5+ For each phase, the following reciprocal equation was applied: G(Si:Si:O) + G(Al:P:O) - G(Al:Si:O) G(Si:P:O) = 0 W. F. Horn and F. A. Hummel, Cent. Glass Ceram. Res. Inst. Bull., 26 [1-4] 47-59 (1979). System Solid phase Description of solid phase Al 2 O 3 -SiO 2 - O 5 AlPO 4 _MT AlPO 4 _HT SiO 2 _HT SiO 2 _MT Al 2 O 3. 4SiO 2. 3 O 5 (no experimental data) (Al 3+, Si 4+ )(P 5+, Si 4+ )(O 2- ) 4 (Al 3+, Si 4+ )(P 5+, Si 4+ )(O 2- ) 4 (Al 3+, Si 4+ )(P 5+, Si 4+ )(O 2- ) 4 (Al 3+, Si 4+ )(P 5+, Si 4+ )(O 2- ) 4 Stoichiometric 13
SiAP_MT T(C) Al 2 O 3 -SiO 2 - O 5 : calculation Al 2 O 3 - SiO 2 - O 5 Projection (Slag), 1 atm; liq IO O 5 O 5 (s2) T(min) = 460.92 o C, T(max) = 2053.83 o C 2100 2500 2300 2100 1900 1700 1500 1300 1100 900 700 Slag ALPO4_HT Slag + ALPO4_HT ALPO4_MT SiO 2 - AlPO 4 1 atm proposed lines from PED database [Horn 1979] MT-AlPO4 HT-AlPO4 HT-AlPO4+glass MT-AlPO4+SiO2_sol_sol ALPO4_HT + SiAP_HT ALPO4_MT + SiAP_HT HT-AlPO4+SiO2_sol_sol glass+ht-alpo4(trace)+sio2_sol_sol glass glass+sio2_sol_sol(trace) ALPO4_MT + SiAP_MT Slag + SiAP_HT SiAP_HT 500 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 SiO 2 /(SiO 2 +AlPO 4 ) (mol/mol) SiAP_MT 1211 54 10 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 SiP2O7(s3) Si O 7 (s2) SiAP_HT Si 5 P 6 O 25 (s) 2 7 AlSi2P3O13(s) ALPO4_MT 3 8 MULLITE Si O 7 (s) 9 P 6 Al 2 O 18 (s) 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 SiO 2 Al 2 O 3 6 ALPO4_HT mole fraction Al 6 O 14 (s) 1 Al 2 O 3 There is not enough experimental data on phase diagrams and compounds. The few data available is contradictory. Hence, experimental studies are needed. 1 12 1900 1650 1400 1150 900 650 400 T o C 14
T(C) Mg 3 O 8 (s) Mg 2 SiO 4 (s) T(C) 2200 MgO-SiO 2 - O 5 : isoplethal sections Mg 2 SiO 4 - Mg 3 O 8 1 atm experiment 2000 1800 1600 exp.points [Wojciechowska 1959] proposed points [Wojciechowska 1959] Slag 1400 Slag + Mg 2 SiO 4 (s) 1200 Slag + Mg 3O 8(s) 1000 Mg 3 O 8 (s) + Mg 2 SiO 4 (s) 800 600 0 0.2 0.4 0.6 0.8 1 Mg 2 SiO 4 /(Mg 2 SiO 4 +Mg 3 O 8 ) (g/g) 2600 SiO 2 - Mg 3 O 8 1 atm exp.points [Wojciechowska 1959] proposed points [Wojciechowska 1959] Slag 2400 2200 exp. points [Wojciechowska 1959] proposed lines [Wojciechowska 1959] Slag Slag + Mg 2 SiO 4 (s) + Mg 2 O 7 (s) Slag + Mg 2SiO 4(s) 2000 1800 Slag + Slag#2 Mg 3 O 8 Slag + Mg 2 SiO 4 (s) Slag + MgSiO 3 (s4) Slag + MgSiO 3 (s4) + Mg 2 SiO 4 (s) MgSiO 3 T(C) 2000 MgSiO 3 - Mg 3 O 8 1 atm 1800 1600 1400 1200 1000 800 MgSiO 3 (s4) + Mg 2 SiO 4 (s) + Mg 2 O 7 (s) MgSiO 3 (s3) + Mg 2 SiO 4 (s) + Mg 2 O 7 (s) MgSiO 3 (s2) + Mg 2 SiO 4 (s) + Mg 2 O 7 (s) 600 0 0.2 0.4 0.6 0.8 1 MgSiO 3 /(MgSiO 3 +Mg 3 O 8 ) (g/g) 1600 1400 1200 1000 800 600 400 Slag + Mg 2O 7 Slag + SiO 2 (s4) SiO 2 (s4) + MgSiO 3 (s4) + Mg 2 O 7 (s) SiO 2 (s2) + MgSiO 3 (s3) + Mg 2 O 7 (s) SiO 2 (s) + MgSiO 3 (s2) + Mg 2 O 7 (s) 200 0 0.2 0.4 0.6 0.8 1 SiO 2 /(SiO 2 +Mg 3 O 8 ) (g/g) J. Wojciechowska, J. Berak, Rocz. Chem., 33[1] 21-31 (1959). 15
MgO-SiO 2 - O 5 : liquidus surface MgO - SiO 2 - O 5 Projection (Slag), 1 atm SiO 2 SiO 2 (s4) T(min) = 559.97 o C, T(max) = 2826.83 o C 2900 MgSiO 3 (s4) MgSiO 3 Slag#2 Mg 2 SiO 4 MgO(s) Mg2SiO4(s) 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 SiO2(s4) 3 2 1 mass fraction 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 4 7 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 MgO O 5 8 Mg 2 O 7(s) M3P M2P MP Mg 3 O 8 (s) 12 1 10 5 Si 5 P 6 O 25 6 911 1314 Si O 7 Si O 7 (s3) Mg O 6 (s) Si O 7 (s2) 15 15 Si O 7 (s) 2750 2500 2250 2000 1750 1500 1250 1000 750 500 T o C J. Wojciechowska, J. Berak, Rocz. Chem., 33[1] 21-31 (1959). There is not enough experimental data on phase diagrams, especially in the O 5 -rich area. The few data available is contradictory. Hence, experimental studies are needed. 16
CaO-SiO 2 - O 5 : section Ca 2 SiO 4 -Ca 3 O 8 -Ca 2 SiO 4, modelled before with solubility for CrO and MgO -Ca 3 O 8 modelled before with solubility for MgO W. Fix, H. Heymann, and R. Heinke, J. Am. Ceram. Soc., 52 [6] 346-347 (1969). 17
CaO-SiO 2 - O 5 : modelling of α-ca 2 SiO 4 Previous description: - Ca 2 SiO 4 : (Ca 2+,Cr 2+,Mg 2+ ) 2 (Si 4+ ) (O 2- ) 4 - Ca 3 O 8 : (Ca 2+,Mg 2+ ) 3 (P 5+ ) 2 (O 2- ) 8 The following description was suggested for the phase C2S-C3P: (Ca 2+,Cr 2+,Mg 2+ ) 3 (Ca 2+,Va 0 ) 1 (P 5+,Si 4+ ) 2 (O 2- ) 8 For the description of C2S-C3P the following reciprocal equation has been applied: G(Ca:Ca:Si:O) + G(Ca:Va:P:O) - G(Ca:Ca:P:O) - G(Ca:Va:Si:O) = 0 System Solid phase Description of solid phase CaO-SiO 2 - O 5 Ca 2 SiO 4 -alpha =Ca 3 O 8 -alpha prime Ca 2 SiO 4 -alpha-prime 7CaO O 5 2SiO 2 5CaO O 5 SiO 2 (Ca 2+ ) 3 (Ca 2+,Va) 1 (P 5+,Si +4 ) 2 (O 2- ) 8 (Ca 2+ ) 3 (Ca 2+,Va) 1 (P 5+,Si +4 ) 2 (O 2- ) 8 Stoichiometric Stoichiometric 18
The phase Ca 2 SiO 4 in different systems 19
CaO-SiO 2 - O 5 : section Ca 2 SiO 4 -Ca 3 O 8 -Ca 2 SiO 4, modelled before with solubility for FeO and MgO W. Fix, H. Heymann, and R. Heinke, J. Am. Ceram. Soc., 52 [6] 346-347 (1969). 20
CaO-SiO 2 - O 5 : modelling of α`-ca 2 SiO 4 The following description characterises the solubility for MgO, FeO and O 5 in the phase -Ca 2 SiO 4 C2S-PRIME : (Ca 2+,Fe 2+,Mg 2+ ) 3 (Ca 2+,Va 0 ) 1 (P 5+,Si 4+ ) 2 (O 2- ) 8 System Solid phase Description of solid phase CaO-SiO 2 - O 5 Ca 2 SiO 4 -alpha =Ca 3 O 8 -alpha prime Ca 2 SiO 4 -alpha-prime 7CaO O 5 2SiO 2 5CaO O 5 SiO 2 (Ca 2+ ) 3 (Ca 2+,Va) 1 (P 5+,Si +4 ) 2 (O 2- ) 8 (Ca 2+ ) 3 (Ca 2+,Va) 1 (P 5+,Si +4 ) 2 (O 2- ) 8 Stoichiometric Stoichiometric 21
The phase Ca 2 SiO 4 in different systems 22
CaO-SiO 2 - O 5 : section Ca 2 SiO 4 -Ca 3 O 8 W. Fix, H. Heymann, and R. Heinke, J. Am. Ceram. Soc., 52 [6] 346-347 (1969). Both phases, α and α,based on Ca 2 SiO 4, are included into the dataset to describe the phase diagram R. W. Nurse, J. H. Welch, W. H. Gutt, J. Chem. Soc.,1077-1083 (1959). 23
CaO-SiO 2 - O 5 : liquidus surface CaO - O 5 - SiO 2 SiO 2 Ca 3 Si 2 O 7 (s) 1500 CaSiO 3 (s) Ca 3 SiO 5 (s) 2600 2800 2400 2200 0.1 0.2 0.3 0.4 MeO 1700 1900 2100 2200 0.1 0.2 0.3 0.4 C2S_C3P J. Berak and J.Wojciechowska, Rocz. Chem., 30[3], (1956), pp.757-769. CaO 0.9 0.8 0.7 mass fraction 0.6 Ca 4 (PO 4 ) 2 O(s) O 5 H. Margot-Marette, P. V. Riboud, Mem. Sci. Rev. Metall., 69 [9] 593-604, (1972). 24
Conclusions The liquid phase in all subsystems was evaluated using non-ideal associate species model (two cations per species). All systems were assessed using experimental phase diagram information. Solid solubility SiO 2 in AlPO 4, and vice versa, was considered. The new models of Ca 2 SiO 4 and -Ca 2 SiO 4 were introduced within the transition from Ca 2 SiO 4 to Ca 3 O 8 as well as the solubility of corresponding oxides have been described. Outlook Addition of alkalis in the Al 2 O 3 -CaO-MgO-SiO 2 - O 5 system Thermodynamic assessment of all combination of 2,3 etc. oxides 25
On behalf of all co-authors: Thank you for your attention! Vielen Dank für Ihre Aufmerksamkeit! Благодарю за внимание! 26