Mass Conservation Problem

[Sol-Chan Han]

Hello Phreeqc users.
I want to ask you about the mass conservation problem.

Following is the input file what I wrote. However, I faced the problem that obtained mass from the result is different from the initial mass. The total initial mass in the system what I set was 881 g (Water: 248 g, cement: 633 g) but the total mass obtained after the simulation is only 873 g (water: 20 g, minerals: 853 g).

I tried to figure out the reason, however, I cannot. I just guess that water mass might be a problem.
Can you give me any clue for this? (attachment is the database what I used.)


PHASES

Tricarboaluminate
   Ca6Al2(CO3)3(OH)12(H2O)26 + 4H+ = 6Ca+2 + 2AlO2- + 3CO3-2 + 34H2O
   -Vm   650.4
   -analytical_expression   246.954198 0 -7758.237633 -85.438635 0 0 0
   -log_K   9.501693
END

SOLUTION 10
-units g/l
redox   O(0)/O(-2)
Temp   25
#O(0)   1   O2(g)   -0.7
O(0)   0.001
-water 0.248 # kg

EQUILIBRIUM_PHASES 10
O2(g)   0   0
CH4(g)   0   0
CO2(g)   0   0
H2(g)   0   0
H2O(g)   0   0
H2S(g)   0   0
N2(g)   0   0
ettringite   0   0
ettringite13   0   0
ettringite9   0   0
thaumasite   0   0
C3AH6   0   0
C3FS1.34H3.32   0   0
C3FH6   0   0
Anh   0   0
Gp   0   0
hemihydrate   0   0
syngenite   0   0
K2SO4   0   0
K2O   0   0
Na2SO4   0   0
Na2O   0   0
C4AH19             0   0
C4AH11      0   0
C2AH7.5   0   0
CAH10      0   0
hemicarbonate      0   0
hemicarbonat10.5   0   0
hemicarbonate9   0   0
monocarbonate   0   0
monocarbonate9   0   0
monosulphate16   0   0
monosulphate14   0   0
monosulphate10_5   0   0
monosulphate9   0   0
#monosulphate1205   0   0
straetlingite5_5   0   0
C4AsClH12   0   0
C4AClH10   0   0
mononitrate   0   0
mononitrite   0   0
C4FH13      0   0
Fe-hemicarbonate   0   0
Femonocarbonate   0   0
AlOHam   0   0
AlOHmic   0   0
FeOOHmic   0   0
Portlandite   0   0
Amor-Sl   0   0
hydrotalcite   0   0
Cal   0   0
Brc   0   0
Fe-ettringite   0   0
monosulphate12      0   0
C4AH13   0   0
Fe-monosulphate   0   0
Tricarboaluminate   0   0

SOLID_SOLUTIONS 10
CHSQ solid solution
   -comp   CSHQ-TobH   0   
   -comp   CSHQ-TobD   0
   -comp   CSHQ-JenH   0
   -comp   CSHQ-JenD   0
   -comp   KSiOH   0
   -comp   NaSiOH   0
(Al-)ettringite-C6As30H30
   -comp   ettringite   0
   -comp   ettringite30   0
#(Al-)ettringite-tricarboaluminate      # End members of Non-ideal S_S were modeled independently as pure phases
#   -comp1   ettringite03_ss 
#   -comp2   tricarboalu03
#   -Gugg_nondim   1.67   0.946
#(Al-)ettringite-Fe-ettringite
#   -comp1   ettringite05   0
#   -comp2   Fe-ettringite05   0
#   -Gugg_nondim   2.10     -0.169
C3(A,F)S0.84H4.32
   -comp   C3FS0.84H4.32   0
   -comp   C3AFS0.84H4.32   0
#Monosulphate-C4AH13
#   -comp1   monosulphate12   0
#   -comp2   C4AH13      0
#   -Gugg_nondim   0.188   2.49
#Monosulphate-Fe-monosulphate
#   -comp1   monosulphate12      0
#   -comp2   Fe-monosulphate   0
#   -Gugg_nondim   
Straetlingite-Straetlingite7
   -comp   Straetlingite   0
   -comp   Straetlingite7   0
Hydrotalcite-pyroaurite S_S
   -comp   Mg3AlC0.5OH   0
   -comp   Mg3FeC0.5OH   0

REACTION 10 #total Mass: 633 kg
CaO   7.21306418
SiO2   2.128138341
Al2O3   0.304210516
Fe2O3   0.126848147
MgO   0.282701469
K2O   0.052416795
Na2O   0.042895174
CO2   0.037397151
SO3   0.18106724
1

SELECTED_OUTPUT
   -file OPC + FA initial hydrates mass - CEMDATA18.spe
   -high_precision ture

#USER_PUNCH
#   -headings NaSiOH KSiOH Na2O K2O Na2SO4 K2SO4 Cal Port Gyp Anhy Hemihy FeOOHmic Bruc Al(OH)3am Al(OH)3mic SiO2am C4AH19 C4AH11 C2AH7.5 CAH10 tot_Hc tot_Mc tot_Ms tot_Str Kuzels Friedels Mononitrate Mononitrite C4FH13 Fe-Hc Fe-Mc C4AH13 Fe-Ms tot_Ett Fe-Ett thaumasite Hydrogarnet C3FS1.34H3.32 Fe-katoite C3(A,F)S0.84H4.32 Syngenite Hydrotalcite TobH TobD JenH JenD Mg3AlC0.5OH Mg3FeC0.5OH Tca
#   -start
#   10 PUNCH S_S("NaSiOH") S_S("KSiOH") equi("Na2O") equi("K2O") equi("Na2SO4") equi("K2SO4") equi("Cal") equi("Portlandite") equi("Gp") equi("Anh") equi("hemihydrate")
#   20 PUNCH equi("FeOOHmic") equi("Brc") equi("AlOHam") equi("AlOHmic") equi("Amor-SI") equi("C4AH19") equi("C4AH11") equi("C2AH7.5") equi("CAH10") (equi("hemicarbonate")+equi("hemicarbonat10.5")+equi("hemicarbonate9"))
#   30 PUNCH (equi("monocarbonate")+equi("monocarbonate9")) (equi("monosulphate16")+equi("monosulphate14")+equi("monosulphate10_5")+equi("monosulphate9")+equi("monosulphate12")+equi("monosulphate1205")) (equi("straetlingite5_5")+S_S("Straetlingite")+S_S("Straetlingite7"))
#   40 PUNCH equi("C4AsClH12") equi("C4AClH10") equi("mononitrate") equi("mononitrite") equi("C4FH13") equi("Fe-hemicarbonate") equi("Femonocarbonate") equi("C4AH13") equi("Fe-monosulphate") (equi("ettringite13")+equi("ettringite9")+S_S("ettringite")+S_S("ettringite30")+equi("ettringite")) equi("Fe-ettringite")
#   50 PUNCH equi("thaumasite") equi("C3AH6") equi("C3FS1.34H3.32") equi("C3FH6") (S_S("C3FS0.84H4.32")+S_S("C3AFS0.84H4.32")) equi("syngenite") equi("hydrotalcite")
#   60 PUNCH S_S("CSHQ-TobH") S_S("CSHQ-TobD") S_S("CSHQ-JenH") S_S("CSHQ-JenD") S_S("Mg3AlC0.5OH") S_S("Mg3FeC0.5OH") equi("Tricarboaluminate")
#   70 PUNCH
#   -end
#END

USER_PUNCH
   -headings TOTCSHQ Port tot_Hc tot_Mc tot_Ms tot_Str tot_Ett Hydrogarnet C3(A,F)S0.84H4.32 Hydrotalcite TobH TobD JenH JenD NaSiOH KSiOH
   -start
   10 PUNCH (S_S("CSHQ-TobH")*124.4910867 + S_S("CSHQ-TobD")*119.7544624 + S_S("CSHQ-JenH")*173.7590676 + S_S("CSHQ-JenD")*169.409645 + S_S("NaSiOH")*67.221076 + S_S("KSiOH")*51.113076) equi("Portlandite")*74.09228
   20 PUNCH (equi("hemicarbonate")*564.45471 + equi("hemicarbonat10.5")*537.43179 + equi("hemicarbonate9")*510.40887)
   30 PUNCH (equi("monocarbonate")*568.44378 + equi("monocarbonate9")*532.41322) (equi("monosulphate16")*694.56848 + equi("monosulphate14")*658.53792 + equi("monosulphate10_5")*595.48444 + equi("monosulphate9")*568.46152 + equi("monosulphate12")*622.50736) (equi("straetlingite5_5")*373.28054 + S_S("Straetlingite")*418.31874 + S_S("Straetlingite7")*400.30346)
   40 PUNCH (equi("ettringite13")*912.79064 + equi("ettringite9")*840.72952 + S_S("ettringite")*1255.08096 + S_S("ettringite30")*1219.0504 + equi("ettringite")*1255.08096)
   50 PUNCH equi("C3AH6")*378.28168 (S_S("C3FS0.84H4.32")*456.2141496 + S_S("C3AFS0.84H4.32")*427.3501496) equi("hydrotalcite")*443.3278
   60 PUNCH S_S("CSHQ-TobH")*124.4910867 S_S("CSHQ-TobD")*119.7544624 S_S("CSHQ-JenH")*173.7590676 S_S("CSHQ-JenD")*169.409645 S_S("NaSiOH")*67.221076 S_S("KSiOH")*51.113076
   70 PUNCH
   -end
END

[dlparkhurst]

I get a total mass of 866.76 g. Run the attached file for details. It uses SYS and GFW functions to sum the masses of solution, minerals, and solid solutions.

You can add PRINT statements in the DO loops, if you want to see the minerals and gram formula weights that are used in the calculation.

[Sol-Chan Han]

Thank you Dr. Parkhurst.

I ran the file you made.
However, still, I cannot understand why the mass of the system is not conserved.
As you noted, after the simulation, the result shows that the total mass of the system is about 866 g rather than 881 g (881 g is the mass that I added as an initial mass).
How can I explain the reason why some portion of the mass (about 15 g) is missing?

[dlparkhurst]

It is not missing. The first USER_PRINT shows that the mass of the initial solution plus the REACTION is 866.76 g.

Code: [Select]

Mass of reaction, g:                          6.1876e+02
Mass of solution before reaction, g:    2.4800e+02
Mass of system g:                             8.6676e+02

The second USER_PRINT sums the solution, the equilibrium phases, and the solid solution masses with the result of 866.76 g. Mass is conserved.

Solution mass, g:                   2.0791e+01
Equilibrium phases mass, g:    2.7252e+02
Solid solution mass, g:            5.7345e+02
Mass of system, g                   8.6676e+02

[Sol-Chan Han]

Oh! Now I can understand what happened.

I really thank you for your great help, Dr. Parkhurst.

[dlparkhurst]

No problem. No Dr.