Characterization of Phase Equilibria and Thermodynamics …
339
• Selected examples demonstrating recent research progress on phase equilibria
in the development of the 19-component database, including equilibria in highPbO-containing low-silica systems, equilibria with Pb metal; equilibria with Cu–
Pb metal alloys; S-containing systems; minor elements distributions; refining
conditions with speiss.
• Examples of industrial applications of the database to the analysis of complex
multi-component systems.
A more detailed review of the information available in the literature of phase equilibria in high-temperature lead smelting and refining systems, and the corresponding
references, will be given in a forthcoming journal version of the paper [3].
Outline of Research Techniques
An overview of the latest advances in the integrated experimental and modelling
research approach to the thermodynamic database development for these pyrometallurgical systems has been provided in [4]. The unambiguous determination of the
unique set of binary and ternary model parameters accurately describing a whole
range of conditions from low- to high-order systems is critical for the accuracy and
predictive power of the tool, and requires experimental data for all binary and ternary
sub-systems, and for selected quaternary sub-systems. If there are no experimental
data—there can be no unique reliable accurate parameters and therefore no reliable
model.
Recently, significant advances in experimental techniques and capabilities have
been achieved due to the development and availability of advanced microanalytical
techniques including (i) electron probe X-ray microanalysis (EPMA) and (ii) laser
ablation inductively coupled plasma mass spectrometry (LAICPMS). These microanalysis techniques provide breakthrough capabilities in phase equilibrium studies
for pyrometallurgical applications greatly extending the range of systems that can
be studied, and the accuracy of characterization with very few limitations on the
range of bulk compositions and conditions that can be characterised. Details of the
experimental technique based on the equilibration at fixed conditions, quenching, and
direct measurement of phase compositions using microanalysis techniques EPMA
and LAICPMS developed by the authors are outlined in the previous publications.
Thermodynamic modelling is performed with the FactSage computer package.
The methodology used for the development of the database involves, first, developing
a preliminary database using experimental data available in the literature data, the
identification of key areas of disagreement or thermodynamic inconsistency, and
the selection of critical experiments required to resolve these inconsistencies or
omissions. The databases are developed so as to achieve a self-consistent set of
parameters for the thermodynamic models, accurately describing phase equilibria
and all other thermodynamic properties for all phases over the complete range of
conditions in terms of temperature, composition, and atmospheric conditions. The
339
• Selected examples demonstrating recent research progress on phase equilibria
in the development of the 19-component database, including equilibria in highPbO-containing low-silica systems, equilibria with Pb metal; equilibria with Cu–
Pb metal alloys; S-containing systems; minor elements distributions; refining
conditions with speiss.
• Examples of industrial applications of the database to the analysis of complex
multi-component systems.
A more detailed review of the information available in the literature of phase equilibria in high-temperature lead smelting and refining systems, and the corresponding
references, will be given in a forthcoming journal version of the paper [3].
Outline of Research Techniques
An overview of the latest advances in the integrated experimental and modelling
research approach to the thermodynamic database development for these pyrometallurgical systems has been provided in [4]. The unambiguous determination of the
unique set of binary and ternary model parameters accurately describing a whole
range of conditions from low- to high-order systems is critical for the accuracy and
predictive power of the tool, and requires experimental data for all binary and ternary
sub-systems, and for selected quaternary sub-systems. If there are no experimental
data—there can be no unique reliable accurate parameters and therefore no reliable
model.
Recently, significant advances in experimental techniques and capabilities have
been achieved due to the development and availability of advanced microanalytical
techniques including (i) electron probe X-ray microanalysis (EPMA) and (ii) laser
ablation inductively coupled plasma mass spectrometry (LAICPMS). These microanalysis techniques provide breakthrough capabilities in phase equilibrium studies
for pyrometallurgical applications greatly extending the range of systems that can
be studied, and the accuracy of characterization with very few limitations on the
range of bulk compositions and conditions that can be characterised. Details of the
experimental technique based on the equilibration at fixed conditions, quenching, and
direct measurement of phase compositions using microanalysis techniques EPMA
and LAICPMS developed by the authors are outlined in the previous publications.
Thermodynamic modelling is performed with the FactSage computer package.
The methodology used for the development of the database involves, first, developing
a preliminary database using experimental data available in the literature data, the
identification of key areas of disagreement or thermodynamic inconsistency, and
the selection of critical experiments required to resolve these inconsistencies or
omissions. The databases are developed so as to achieve a self-consistent set of
parameters for the thermodynamic models, accurately describing phase equilibria
and all other thermodynamic properties for all phases over the complete range of
conditions in terms of temperature, composition, and atmospheric conditions. The