Lime precipitation

[soza]

I am trying to understand lime treatment reaction for mine flows. I want to be able to calculate the lime amount in "mg/L" similar to hardness removal in water treatment. please verify the logic below and advise on how to improve the code. Further, how to convert the units in output file?

TITLE Tria1, Part A.--MH WQ data.
SOLUTION 1  MH WQ
        units   ppm
        pH      4.6
        temp    10.0
        Ca              375.0
        Mg              2605.0
        Na              79.0
        K               0.0
        Cl              20.20
        Alkalinity      33.06 as HCO3
        S(6)            12497.0    CHARGE
   N(-3)         1.81
   N(5)         0.5
   Co         1.71
   Al         15.6
   Cu         1.71
   Fe         317
   Mn         38.2
   Ni         4.6
   Zn         10.41
END
TITLE Tria1, Part B.--RS WQ data
SOLUTION 2  RS WQ
        units   ppm
        pH      3.8
        temp    12.3
        Ca              62.6
        Mg              61.3
        Na              41.0
        K               0.0
        Cl              27.7
        S(6)            664.8      CHARGE
   N(-3)         0.0
   N(5)         2.4
   Co         0.0
   Al         26
   Cu         2.1
   Fe         0.047
   Mn         61.3
   Ni         0.2
   Zn         0.9
END
TITLE Tria1, Part C.--EFPB WQ data
SOLUTION 3  EFPB WQ
        units   ppm
        pH      6.82
        temp    11.98
        Ca              375.64
        Mg              155.7
        Na              324.72
        K               0.0
        Cl              99.64
        S(6)            1963.4   CHARGE
   N(-3)         9.83
   N(5)         0.12
   Co         0.0
   Al         0.0
   Cu         2.99
   Fe         0.04
   Mn         16.54
   Ni         0.2
   Zn         0.03
END
TITLE Mixing Three flows_Tria1, Part D.--Mix 70 MH, 30 RS, 40 EFPB.
MIX 1
    1    70
    2    40
    3    40
SAVE solution  4 
END

use solution 4

EQUILIBRIUM_PHASES 1
    Calcite   0 0 precipitate_only
    Dolomite  0 0 precipitate_only
TITLE Equilibrate with lime
REACTION 1
    Portlandite 1
    1 moles in 25 steps

USER_GRAPH 1
    -headings               x Ca Mg Na pH
    -axis_titles            "portlandite added in moles" "mg/l" "pH"
    -chart_title            "Portlandite Titration"
    -initial_solutions      false
    -connect_simulations    true
 #   -plot_concentration_vs  x
  -start

10 GRAPH_x step_no/25          #from 1 mol in 25 steps above
20 GRAPH_y tot("Ca") * 40.08e3
30 GRAPH_y tot("Mg") * 24.30e3
40 GRAPH_y tot("Na") * 23.00e3
50 GRAPH_SY -la("H+")
 END

[Farshad]

Hello Every body
I want use PHREEQC to Softening water.
Could you please let me know where is my fault in coding ?
I added NaOH to reach pH to 7.9 and after that Na2CO3 , But Ca2+ is reduced very slightly:

PHASES
Calcite
    CaCO3 = Ca+2 + CO3-2
    log_k -8.48
    delta_h -9.42 kcal

Brucite
    Mg(OH)2 = Mg+2 + 2OH-
    log_k -11.15
    delta_h -10.5 kcal

SOLUTION 1 Initial_Water
    temp      25
    pH        7
    pe        4
    redox     pe
    units     mg/l
    density   1
    Alkalinity 200 as HCO3
    Ca        700
    Cl        20
    Mg        50
    Na        10
    C(4)      200
    -water    1 # kg

REACTION 1
    NaOH       0.1
    0.0     0.01  # Adjust the amount of NaOH to achieve pH 7.9

SAVE solution 1

USER_GRAPH 1
    -headings               "NaOH" "Ca" "pH"
    -axis_titles            "NaOH(moles)" "Concentration (mg/L)" "pH"
    -initial_solutions      false
    -connect_simulations    true
    -plot_concentration_vs  x
    -start
10 GRAPH_X RXN
20 GRAPH_Y MOL("Ca+2")
30 GRAPH_SY -LA("pH")
    -end

USE solution 1

REACTION 2
    Na2CO3     0.1
    0.1 moles in 100 steps

USER_GRAPH 2
    -headings               "Na2CO3 (moles)" "Ca (mg/L)" "pH"
    -axis_titles            "Na2CO3 (moles)" "Concentration (mg/L)" "pH"
    -initial_solutions      false
    -connect_simulations    true
    -plot_concentration_vs  x
    -start
10 GRAPH_X RXN
20 GRAPH_Y MOL("Ca+2")
30 GRAPH_SY -LA("pH")
    -end

EQUILIBRIUM_PHASES 1
    Brucite   0 0
    Calcite   0 0

USE solution 1

EQUILIBRIUM_PHASES 2
    Calcite 10^-6 10^-6
    Brucite 0 0