Click on Download Predom Slide Show (pdf presentation - 34 pages) for detailed information on the Predom Module.

The Predom module enables you to calculate and plot isothermal predominance area diagrams for one-, two or three-metal systems using data retrieved from the compound databases.

For example, Fig. 2 shows the entry and resulting diagram for the one-metal Cu-Pso₂-Po₂ system at 1000 K. After the components (Cu, S and O) have been specified, the user is presented with a list of possible axes, log₁₀X and log₁₀Y (X and Y are pressure or activity of S, S₂, …S_n, SO, SO₂, SO₃, O₂ etc.), and possible product species (gases, solids, liquids – these may be edited by clicking on the “List” button). A useful feature of the module is the option to include the calculated total pressure isobar on the predominance diagram (plotted as “+”s in Fig. 2). Along such an isobar the total pressure is the sum of the partial pressures of all the gaseous species (in Fig. 2, P(total) = 1 atm = Ps + Ps₂ + … Ps_n + Pso + Pso₂ + Pso₃ + Po₂ + Pcu … etc.). Such a line represents the reaction path whereby, for example, Cu₂S oxidizes to, say, Cu₂O.

Fig 3. shows the effect of temperature on the Cu-Pso₂-Po₂ system.

Fig 4. displays the calculated diagram and invariant points of Fe-Pso2-Po2 at 1000 K. A detailed point calculation at Pso₂ = 0.8 atm and Po₂ = 0.2 atm is presented in Figs 5 and 6.

The calculated diagrams can be stored as figure (*.fig) files, edited by the Figure module, and exported as *.bmp, *.emf and *.wmf files.

Predom also enables you list the coordinates all the invariant points as well as perform detailed equilibrium calculations at any point on the diagram.

Fig. 1 - Predom Module Fig. 2 - Predom Module - Top: entry of the one-metal Cu-p(SO2)-p(O2) system at 1000K. Bottom: resulting calculated predominance diagram. Fig. 3 - Predom Module - Superimposed Predom diagrams for Cu-SO2(g)-O2(g) at 1000, 1100 and 1200K. Fig. 4 - Predom Module - Invariant points of Fe-SO2(g)-O2(g) at 1000K. Fig. 5 - Predom Module - Detailed point calculation at Pso2 = 0.8 atm and Po2 = 0.2 atm for Fe-SO2(g)-O2(g) at 1000K. Fig. 6 - Predom Module - Detailed point calculation at Pso2 = 0.8 atm and Po2 = 0.2 atm for Fe-SO2(g)-O2(g) at 1000K.