contour_hfos.ppi

# produces a contour plot for the Fe-H2O system with FeT = 0.01 mol/kgw and Fe(OH)3(a) as a possible mineral phase
# select contours from 'simplified' percentiles, i.e. percentiles with pruning

SPECIATION
  calculationType                      "contour"
  calculationMethod                    1
  contourZvariable                     FeT                                     # plot is for FeT defined in USER_PUNCH
  xmin                                 2.0                                     # pH range
  xmax                                 12.0
  ymin                                 -90.0                                   # fO2(g) range (controls the redox)
  ymax                                 0.0
  resolution                           50                                      # calculate a 50 x 50 grid

PLOT
  plotTitle                            "Fe solubility<br>(b) simplified percentile contours"
  xtitle                               pH
  ytitle                               "log <i>f</i> O<sub>2</sub>(g) (atm)"

  contours                             auto 17 s    # 17 contour levels based on smoothed (approx) percentiles
  contourFillcolor                     auto
  contourLineWidth                     auto
  contourLineColor                     auto
  contourShiftLabel                    c
  contourLabelSize                     2
  contourLabelFont                     "Helvetica"
  contourLabelColor                    auto
  contourlabelFigs                     auto

  extraText                            extratextcontour_hfo.dat 

CHEMISTRY

# first simulation
PHASES
Fix_H+; H+ = H+; log_k 0.

SELECTED_OUTPUT
-reset FALSE
-high_precision TRUE

USER_PUNCH
-headings  FeT
10 PUNCH log10(TOT("Fe"))

SOLUTION 1
   pH        1.8
   units     mol/kgw
   Fe(3)     1e-2
   Na        1e-1
   Cl        1e-1
END

# second simulation - loop on this
USE solution 1
EQUILIBRIUM_PHASES 1
   Fix_H+ -<x_axis> NaOH 10                                                    # N.B. this works because <x_axis> is substituted without any leading spaces
     -force_equality true                                                      #   for negative values of <x_axis> would have to form a new tag to avoid --value
   O2(g)  <y_axis> 0.1
   Fe(OH)3(a) 0 0                                                              # the only mineral allowed to form - must be in the database used
END                                                                            #   0 0 means achieve SI=0 and size of initial reservoir is 0 mol Fe(OH)3(a)
                                                                               #   i.e. allow to precipitate but none there to dissolve