NiS.ppi

# predominance diagram for Ni in the presence of S and C (employing the Halite ploy)

SPECIATION
  jobTitle                             "Ni-S-C-H2O"
  calculationType                      ht1
  calculationMethod                    1
  mainSpecies                          "Ni"
  xmin                                 2.0                # calculate pH 2-10
  xmax                                 10.0
  ymin                                 -80.0              # calculate log f(O2(g)) -80 to 0
  ymax                                 0.0

  resolution                           250                # track on a 250 x 250 grid

PLOT
  plotTitle                            "Ni-S-C-O<sub>2</sub>-H<sub>2</sub>O at 20<sup>o</sup>C"
  xtitle                               pH
  ytitle                               "log <i>f</i> O<sub>2</sub>(g)"
  extraText                            "extratextNiS.dat"


CHEMISTRY

# first simulation - initial solution calculation

include 'ht1s.inc'                                          # standard predominance diagram code

SOLUTION 1
   Temp      20
   pH        1.8                                           # initial pH less than pHmin to hope that Fix_H+ works (but see below)
   units     mol/kgw
   Ni        1e-2                                          # total Ni etc
   S(6)      1e-2
   Na        1e-1 charge                                   # background electrolyte
   Cl        1e-1
END


# second simulation

USE solution 1
EQUILIBRIUM_PHASES 1
   Fix_H+     -<x_axis> NaOH                               # Fix_H+ defined in ht1.inc
     -force_equality true
   O2(g)      <y_axis>
   CO2(g)     -1.5       1                                 # limit max CO2 supplied to 1 mol

   Millerite                      0 0                      # list of possible minerals
   Sulfur                         0 0
   Ni(OH)2                        0 0
   Halite                         -12 1 dis                # reduction of S(6) produces a lot of OH- so may actually need HCl
   Bunsenite                      0 0                      #  (or -NaOH) to adjust pH - can't specify +NaOH and +HCl so use -NaOH.
   NiCO3                          0 0                      #   This Halite phase ensures that there will always be some Na to take away.
   Nahcolite                      0 0                      #   To avoid this, either reduce initial pH to pH 1 or add more Na(Cl) or add less S(6).
   Morenosite                     0 0
   Retgersite                     0 0
   Natron                         0 0
   Thermonatrite                  0 0
   Thenardite                     0 0
   Mirabilite                     0 0
   Ni4(OH)6SO4                    0 0
   Trona                          0 0
END