Adding oxide compounds to the Cemdata18 database

[sama.k]

Hello;

I am trying to model the cement paste. So, I have to use the Cemdata18 database which is a database for cementitious materials and contains cement hydration products (The database is attached). In this simulation, I need to model the metakaolin as one of the raw materials with the following Chemical and mineralogical composition (wt%):
SiO2=52.84, Al2O3= 39.49, Fe2O3= 1.42, CaO= 0.22, MgO= 0.48, K2O= 1.00, Na2O= 0.05, SO3= 0.06, TiO2= 0.88, P2O5= 0.11

CaO, Fe2O3, K2O, and Na2O are defined in the database. I defined MgO (Periclase), Al2O3, and SO3 using PHASES Keyword as the following code. Could you please assist me on how I can model TiO2, P2O5, and SiO2 (Given that Ti and  P aren't defined in this database).
I would also be very grateful if I can have information about the dissolution reactions, log k, and delta H of the TiO2, P2O5, and SiO2.


Any help or advice will be greatly appreciated.
Many thanks

Code: [Select]

PHASES
periclase
    MgO + 2H+ = H2O + Mg+2
    log_k     21.5841
    delta_h   -151.23 kJ
alminium_oxide
    Al2O3 + 6H+ = 2Al+3 + 3H2O
    log_k     19.6224
    delta_h   -258.59 kJ
sulfur_trioxide
    SO3-2 + H+ = HSO3-
    log_k     7.22
    delta_h   10.72 kJ


[dlparkhurst]

You only need to define the minerals in PHASES that you want to use in EQUILIBRIUM_PHASES or SOLID_SOLUTIONS. You do not need to define an oxide, unless it may form as a mineral in the cement. You can define a REACTION that adds the appropriate amount of elements, while the minerals that may form would be defined by EQUILIBRIUM_PHASES (or SOLID_SOLUTIONS or KINETICS). You can define a REACTION as follows without defining PHASES.

Code: [Select]

REACTION 1
#Element      mol/g        Percent 
SiO2         8.7959e-03 # 52.84
Al2O3        3.8737e-03 # 39.49
Fe2O3        8.8930e-05 #  1.42
CaO          3.9235e-05 #  0.22
MgO          1.1911e-04 #  0.48
K2O          1.0617e-04 #  1.00
Na2O         8.0680e-06 #  0.05
SO3          7.4955e-06 #  0.06
TiO2         1.1018e-04 #  0.88
P2O5         7.7510e-06 #  0.11
15.0 # define number of grams here

As for Ti and P, you can (1) ignore them, (2) add definitions for P and Ti in SOLUTION_MASTER_SPECIES and SOLUTION_SPECIES to CEMDAT, or (3) copy the PHASES definitions from CEMDATA, add them to the input file, and use another database (most have P, core10 and llnl.dat have Ti). For option 2 and 3, you also would have to decide which minerals in cement would contain P and Ti; so, you may need to define new PHASES for P and Ti.

Note your definition of sulfur_trioxide is unnecessary, but incorrect. You should define a reaction from SO3, no charge.