> I am trying to use PHREEQC to simulate the formation of green rust (iron corrosion product). Its formula is considered to be Fe4Fe2(OH)12SO4------the first Fe is in 2nd valence and the second Fe is in 3rd valence (So I might write it as Fe(II)4Fe(III)2(OH)12SO4. But the PHASE data block in PHREEQC seems only to accept single valent element on left hand side. I thought of SOLID-SOLUTION but the green rust is not yed considered as any aggregate of other phases. I don't know if there is any other way to handle this problem. > the reaction equation is: > Fe4Fe2(OH)12SO4 = 5Fe(OH)2 + Fe2+2 + SO4-2 + 1/2O2 + H2O This equation should be adequate for the PHASE definition. I just did a little balancing for PHREEQC: Fe4Fe2(OH)12SO4 = 5Fe(OH)2 + Fe+2 + SO4-2 + 0.5O2 + H2O If this stoichiometry is added to solution, the iron will be distributed between +3 and +2 states depending on electron acceptors. With no additional electron acceptors in the system the ratio of Fe(2):Fe(3) should be 2:1. David David Parkhurst (dlpark@xxxxxxxx) U.S. Geological Survey Box 25046, MS 413 Denver Federal Center Denver, CO 80225 Project web page: https://wwwbrr.cr.usgs.gov/projects/GWC_coupled
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