Jump to content
Geochemist's Workbench Support Forum

lea512

Members
  • Posts

    8
  • Joined

  • Last visited

Posts posted by lea512

  1. Ok, I think I may understand. What I was doing was running the model that contained about 9 minerals (with kinetics) for about 10 years and Quartz and Kaolinite were always supersaturated while everything else was either in equilibrium or undersaturated. So if I understand correctly, quartz and kaolinite just haven't reached equilibrium yet?

     

    Thanks for the help!!

     

    Lea

  2. Hello again,

     

    Ok, so if the minerals in the system are in equilibrium with the fluid, what do the grams and volume of each mineral represent?

     

    In addition, I am adding CO2 into the system and sliding the fugacity which increases the acidity of the fluid, which means that I shouldn't have any minerals that are supersaturated (I am also adding in kinetic minerals and their dissolution rate). Quartz and kaolinite, however, are always supersaturated, but I have found that just adding these minerals in equilibrium eliminates this issue. Is there a better way kinetically to make it to where these two minerals are just in equilibrium or saturated in the fluid?

  3. Tom,

     

    Thank you for the information, it really helped me out. However, I think where I was getting confused was with the "Minerals in System" results. Are these minerals that the model has predicted have precipitated along with their amounts in grams and volume (cm3)? I notice that most of the minerals within the "Minerals in the system" heading are saturated in solution. Anyway, if you could clarify what exactly the "minerals in the system" heading provides results for, that would help me out tremendously.

  4. Hello,

     

    I am currently trying out new water chemistry and mineral data in REACT (compared to a previous forum discussion). I am using kinetic data in REACT and do not want any minerals to precipitate in the reaction. However, when I turn precipitation off, the reaction path says it is abandoned and only provides results for a couple of steps. How do I not allow mineral precipitation with kinetic data? Do I need to use only equilibrium data for no minerals to precipitate?

     

    I have provided the file.

     

    Thanks,

     

    Lea

    1755-1WaterChem_other SS.rea

  5. Hi Lea:

     

    Are either of these clays observed in the system you are studying? Because in the equilibrium model you've constructed, neither are stable after being titrated. I'm wondering if you need to either consider moving to a kinetic model, or titrating minerals in that have greater long term stability....

     

    I hope that helps,

     

    Tom Meuzelaar

    RockWare, Inc.

     

    Actually I have been using both smectites in a kinetic model. Currently, I am working with a carbon sequestration team that is in the planning/researching stages (and writing my thesis) where drilling has yet to begin and we have no data (some mineralogical). Some members on the team believe that we should forget the kinetics and just consider everything in equilibrium. Plus, I was trying to run both kinetic and equilibrium models together to compare how much the concentrations vary from model to model over a period of time. Just a thought. Do you have any suggestions (based on my input data) about how to improve my model for carbon sequestration? Also, I have no actual water chemistry data from the aquifer that we plan to inject into (the water data above is from 200+ miles away). Do you have any suggestions as to how to determine water chemistry data from using only mineralogical data?

     

    Thanks again.

    Lea

  6. Recently, I have been trying to input both high Fe,Mg-rich smectite and low Fe,Mg-rich smectite into my equilibrium model. When I input the values (in grams) that I want, I get this message at the bottom of the "Run" tab

     

    Cutting step size to find phase assemblage

    Swapping K+ in for Clinoptil-K

    Swapping Hematite in for Nontronit-Mg

    Swapping Mg++ in for Clinoptil-Ca

    Swapping SiO2(aq) in for Kaolinite

    Swapping Fe++ in for Pyrite

    Residuals too large, 661-th interation

    -- Didn't wake up, abandoning path

     

    However, when I change the low-fe-mg-smectite to a smaller value, it seems to work correctly. I would really like to use my value, but if I am doing something incorrectly, please let me know. I have provided my input data below to help in my explanation.

     

     

    Input Data:

     

    Water Chemistry

    H2O = 1 kg

    Ca2+ = 63.8

    Na+ = 6.5

    Mg2+ = 46.9

    SO4-- = 100

    Cl- = 5

    HCO3- = 293 charge balance

    H+ = 7.5

    Fe2+ = 0.11

    Mn2+ = 0.05

    K+ = 1.8

    O2(aq) = 0.01

    SiO2(aq) = 0.01

    Al3+ = 0.01

     

    Mineral Data

    Quartz = 1899.96 g in rxn

    K-Feldspar = 112.4 g in rxn

    Albite = 18.74 g in rxn

    Kaolinite = 89.91 g in rxn

    Illite = 1101.84 g in rxn

    Hematite = 67.44 g in rxn

    Goethite = 67.44 g in rxn

    Low Fe,Mg-rich Smectite = 200 g in rxn (I WANT THIS TO = 1035.61g INSTEAD!!)

    Fe,Mg-rich Smectite = 498.72 g in rxn

     

    Other Data

    Temperature = 30C

    Time = 0-20 years

    Sliding CO2 (g) Fugacity to 53.3 bar

    NS4C-1836-1_equil.rea

×
×
  • Create New...