Iron oxides and iron sulfides stability diagram

[franky_ztein]

Hi,

 

I'm a GWB newbie, I mean really. Is there anyone with a GWB stability diagram template on following iron species - Fe3O4, Fe2O3, FeS, FeS2, Fe-Al-Silicates, Fe - on log P(H2S) and log P(H2) axes? I'm trying to determine the iron-minerals that are buffering the relative composition of my H2S and H2 gases in a hydrothermal environment. Based on my gas geothermometer, the equilibration temperatures of the different gas samples are between 290 to 310°C. So I hope to construct 5 diagrams at 220, 260, 290, 300 and 310°C. The first two are just for comparative analyses, see how the stability fields of the minerals grow or shrink as the temperature increases. I will use the last 3 for overlaying the gas pressures I calculated for the deep hydrothermal reservoir.

 

Would be very, very much grateful for any help. GWB is hard. whew.

 

Franky

[Brian Farrell]

Hi Franky,

 

There are a number of example redox-activity diagrams in the GWB Essentials Guide. I think the examples depicted in Figure 5.2b and Figure 5.5 should be especially helpful in creating your diagrams. You should note that the default thermodynamic datasets distributed with GWB cover the temperature range 0 - 300 C. If you have log K data (and estimates for some Debye-Huckel parameters), you should be able to modify your thermo dataset without too much trouble (See the Thermo Data Appendix to the GWB Reference Manual).

 

Hope this helps,

Brian Farrell

Aqueous Solutions LLC

[franky_ztein]

Hi Brian,

 

Thank you very much for your reply. I'll look this up.

 

Cheers,

 

Franky