MTDATA API - Introduction and Latest Developments

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MTDATA
DATA ISSUES
John Gisby, Hugh Davies NPL Materials
Centre, National Physical Laboratory
March 2002
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• DATA ISSUES
• MODELS
• KCl-CaCl2 as an example
• DATA ASSESSMENT
• NiO-Al2O3 as an example
• DATA FOR OXIDE SYSTEMS
• MIRO project RC132

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• MODELS
• Gibbs energy of each phase is expressed as a
  function of
• temperature, composition and possibly pressure
• KCl-CaCl2 as an example

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• Stoichiometric substance or solution phase end
  member
• GCaKCl3 A BT CTlnT DT2 ET3 F/T
• Solution phase (Redlich-Kister model for Gex)
• GLIQUID xKCl GKCl xCaCl2 GCaCl2
• RT xKClln xKCl RT xCaCl2ln xCaCl2
• Gex
• Gex (L00L01T) xKClxCaCl2
• (L10L11T) xKClxCaCl2 (xKCl-xCaCl2)
• (L20L21T) xKClxCaCl2 (xKCl-xCaCl2)2

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• GCaKCl3 A BT CTlnT DT2 ET3 F/T

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• Gex (L00L01T) xKClxCaCl2 (L10L11T)
  xKClxCaCl2 (xKCl-xCaCl2)
• (L20L21T) xKClxCaCl2 (xKCl-xCaCl2)2

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• Gex (L00L01T) xKClxCaCl2 (L10L11T)
  xKClxCaCl2 (xKCl-xCaCl2)
• (L20L21T) xKClxCaCl2 (xKCl-xCaCl2)2

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• NOT JUST CURVE FITTING
• Underlying thermodynamic properties must be taken
  into account
• as well as phase boundaries

Enthalpy of mixing
Activity of KCl
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• MISSING DATA
• If GEX data for a particular interaction are
  missing, calculations can be performed assuming
  ideal mixing
• likely to be OK for interactions between minor
  species,
• but not for major species

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• DATA ASSESSMENT
• NiO-Al2O3 as an example

• EXPERIMENTAL DATA
• phase diagram (1963)
• liquidus points (1932)
• compositions of spinels in equilibrium with Al2O3
  (1965, 1981 and others)
• thermodynamic properties of NiAl2O4 spinel
• degree of inversion of NiAl2O4 spinel (1989,
  1992 and earlier)

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SPINEL MODEL  (Ni2, Al3)1 (Ni2, Al3, Va)2
(Va)2 (O2-)4 normal NiAl2O4 - (Ni2) (Al3
Al3) (Va)2 (O2-)4 inverse NiAl2O4 - (Al3)
(Ni2 Al3) (Va2) (O2-)4   degree of inversion
is the fraction of sites on the first sublattice
occupied by Al3  
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• INITIAL PHASE DIAGRAM
• AND DEGREE OF INVERSION

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• CHANGING ENTHALPY / ENTROPY DATA FOR TWO SPINEL
  UNARIES
• TO MODEL DEGREE OF INVERSION,
• GIBBS ENERGY OF FORMATION AT 298.15 K,
• AND MELTING POINT OF NiAl2O4 SPINEL

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• NEW PHASE DIAGRAM
• AND DEGREE OF INVERSION PLOT

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• NOW INTRODUCE INTERACTION PARAMETERS IN SPINEL
  PHASE
• TO MODEL EQUILIBRIA WITH Al2O3 (CORUNDUM)

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• NOW INTRODUCE INTERACTION PARAMETERS IN LIQUID
  PHASE
• TO MODEL LIQUIDUS

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• FINAL PHASE DIAGRAM
• (AND COMPARISON BETWEEN CALCULATED AND
  EXPERIMENTAL DATA)

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• MIRO(Mineral Industry Research
  Organisation)Projects RC54, RC81 and RC132
• To develop a high quality, comprehensive
  thermodynamic database for oxide and sulphur
  containing systems of industrial interest for use
  in predictive phase equilibrium calculations
• Facilitates calculations directly relevant to
  industrial processes for temperature and
  composition ranges outside the scope of hard copy
  phase diagram compilations
• Systems and priorities determined by the
  sponsors
• Database validated against plant / process data
  by sponsors

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SPONSORS(current sponsors in white)

• Johnson Matthey AEA Technology
• Rio Tinto Outokumpu Oy
• Corus Pilkington
• Federal Mogul BNFL
• Amplats MetalEurop
• Sheffield University Shell
• Britannia Zinc DTI

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• CURRENT ELEMENTS
• Al, B, Ba, Ca, Cr, Cu, Fe, K, La, Li, Mg, Mn, Na,
  Ni, O,
• Pb, S, Si, Sr, U, Zn, Zr
• CURRENT SYSTEMS
• Na2O-K2O-CaO-Fe-O-MgO-Al2O3-SiO2-S
• Na2O-CaO-Fe-O-MgO-Al2O3-B2O3-SiO2
• Li2O-Na2O-B2O3-SiO2
• CaO-Cu-O-Fe-SiO2 (-MgO-Al2O3)
• CaO-Fe-O-MnO-MgO-Al2O3-SiO2
• CaO-Fe-O-PbO-ZnO-Al2O3-SiO2
• CaO-MgO-Al2O3-SiO2-ZrO2
• CaO-Cr-O-Fe-MgO-Al2O3-SiO2
• CaO-Fe-O-MgO-NiO-Al2O3-SiO2
• Cu-Fe-Ni-S-O (mattes / alloys)
• Some BaO, La2O3, SrO, UO2 containing binary
  systems

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• AREAS BEING CONSIDERED FOR FUTURE WORK
• CONTINUE TO EXTEND COVERAGE OF CURRENT OXIDES
• plus
• addition of Co, Mn, Pb to matte / metal phase
• addition of CoO, TiO2, V2O3, rare earth oxides to
  oxide phases
• molten salt - oxide systems
• (including addition of CaF2 to oxide phases)
• inclusion of P, As
• inclusion of H2O (at high and low temperatures)
• modelling volume changes in oxide phases

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• APPLICATIONS
• Preventing iron formation in zinc blast furnace
• Analysing possible consequences of nuclear
  reactor accident
• Modelling inclusion formation in steels
• Analysing problems associated with glass making
• Optimising recovery of Cu, Ni, precious metals
• Investigating refractory wear
• Improving understanding of cement manufacturing
  process
• Modelling of corrosion
• Pollution control
• Process modelling (links with other commercial
  software)
• Analysing why borax additions to steelmaking
  slags reduce
• dust generation after solidification