Plotting more than one mineral solubility curve on a PHREEQC graph

[J.Hopwood]

I am interested in showing more than one solubility curve on a graph. The following input file is for gypsum. I am wondering how I would adapt the file so that a curve for anhydrite also appears? Help with this would be much appreciated.


PHASES
Fix_H+
H+ = H+
log_k 0
END
# pH-dependent Ca concentration in equilibrium with gypsum and pH-dependent Ca concentration in equilibrium with anhydrite
#
SOLUTION 1
    temp      25
    pH        3
    pe        4
    redox     pe
    units     mmol/kgw
    density   1
    Cl        1 charge
        -water    1 # kg

SELECTED_OUTPUT; -reset false; -file barite.prn
USER_PUNCH
20 sc$ = chr$(59)
30 for i = 3.5 to 12 step 0.5
40   punch "USE solution 1",EOL$
50   PUNCH "EQUILIBRIUM_PHASES",EOL$,"Gypsum",EOL$,"Fix_H+ ",-i," NaOH 10",EOL$
60   punch "END" + eol$
70 next i
-end
END
USER_GRAPH 1
    -axis_titles            "pH" "( Ca_tot / uM )" "(S_tot / uM)"
    -chart_title            "Gypsum Equilibrium"
-headings x Ca SO4
-connect_simulations
 -initial_solutions true
 -start
10 graph_x -la("H+")
20 graph_y (tot"Ca")*1e6
30 graph_sy (tot"S(6)")*1e6     #conc of sulphate on secondary y axis
  -end
    -active                 true
END

PRINT; -reset false; -selected_out false
INCLUDE$ gypsum.prn
END

[dlparkhurst]

PHASES
Fix_H+
H+ = H+
log_k 0
END
# pH-dependent Ca concentration in equilibrium with gypsum and pH-dependent Ca concentration in equilibrium with anhydrite
#
SOLUTION 1
    temp      25
    pH        3
    pe        4
    redox     pe
    units     mmol/kgw
    density   1
    Cl        1 charge
    Ca         1
        -water    1 # kg

SELECTED_OUTPUT 1; -reset false; -file gypsum.prn
USER_PUNCH 1
20 sc$ = chr$(59)
30 for i = 3.5 to 12 step 0.5
40   punch "USE solution 1",EOL$
50   PUNCH "EQUILIBRIUM_PHASES",EOL$,"Gypsum",EOL$,"Fix_H+ ",-i," NaOH 10",EOL$
60   punch "END" + eol$
70 next i
-end

SELECTED_OUTPUT 2; -file anhydrite.prn
USER_PUNCH 2
20 sc$ = chr$(59)
30 for i = 3.5 to 12 step 0.5
40   punch "USE solution 1",EOL$
50   PUNCH "EQUILIBRIUM_PHASES",EOL$,"Anhydrite",EOL$,"Fix_H+ ",-i," NaOH 10",EOL$
60   punch "END" + eol$
70 next i
-end
END
USER_GRAPH 1
    -axis_titles            "pH" "( Ca_tot / uM )" "(S_tot / uM)"
    -chart_title            "Gypsum & Anhydrite Equilibrium"
-headings x Ca_gyp SO4_gyp
-connect_simulations
 -initial_solutions true
 -start
10 graph_x -la("H+")
20 graph_y (tot"Ca")*1e6
30 graph_sy (tot"S(6)")*1e6     #conc of sulphate on secondary y axis
  -end
    -active                 true
END

PRINT; -reset false; -selected_out false
INCLUDE$ gypsum.prn
END
USER_GRAPH 1
-headings x Ca_anh SO4_anh
INCLUDE$ anhydrite.prn
END

[J.Hopwood]

Many thanks David, I appreciate that.