FTA
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Posts posted by FTA
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Hi
Looks like as if GWB, or at least Act2, skips minerals having large log K values, as is the case of enargite
Enargite type=
formula= Cu3AsS4
mole vol.= 88.350 cc mole wt.= 393.7996 g
6 species in reaction
3.000 Cu+ 1.000 As(OH)4- 4.000 SO4--
-5.000 H2O -7.500 O2(aq) 6.000 H+
465.4360 414.1113 362.0154 312.9855
263.9463 221.6313 186.0364 156.4474
These data should be OK since are similar to those of the SOLTHERM data file. Do you any way of avoiding this problem?
Thanks
Minerals with high log K
in The Geochemist's Workbench
Posted
Hi Brian
Let me clarify the problem. Enargite is NOT included in the original databases but I have calculated the constants from other sources. However, log K values are really high and in the GWB databases we cannot lower logK by division since the program constrains that the minerals always have a coefficient in the reaction of 1. Also, it looks like that in the GWB databases unknown log K values are set to 500; I wonder if there is any instruction that simply skips minerals having high log K - at least in version 8.0. In fact, when having a look to the log of the diagrams in Act2, enargite simply does not exist as loaded mineral despite it is in the database as has been checked in Config/Show.
Any idea?
Thanks
Fernando