Applications and Case Studies > Acid mine/rock drainage

Lime precipitation

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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