[OLD] Pickup fluid problem

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From: Richard Laffers

Subject: Pickup fluid problem

I encountered a wierd problem with "pickup fluid" command, documented by the attached script: REACT calculates a hypothetical reaction path with sliding temperature. At the end of the React_output_1.txt (the last reaction step) I checked the bulk concentrations of basis species. There is a difference in number of total moles of Al+++ and number of moles of Al+++ in fluid, though the system contains no minerals (flow-through option). Why?

Then the fluid is picked up. Here I noticed, that the amount of Al+++ is picked up in terms of free molality, in contrast to other elements (except for H+, which is OK). Why? If I now make equilibrium calculation, the resulting fluid should be the same as at the end of React_output_1.txt, but it is not. The difference is in Al+++ bulk concentration, ionic strength, and mineral saturations. Why "pickup fluid" did not pick up exactly the same fluid from the end of the reaction path?

I noticed, that "pickup fluid" command works perfectly when flow-through option is off. React-GWB 4.0.3, Win XP, thermo.com.v8.r6+.dat

 

data = "C:Program FilesGwbGtdatathermo.com.v8.r6+.dat" verify

temperature initial = 300, final = 200

swap Quartz for SiO2(aq)

1 kg free H2O

free gram Quartz = 5000

total g/kg Na+ = 40

balance on Cl-

total g/kg Cl- = 50

total molality Al+++ = .001

pH = 5

 

dump

flow-through

printout surfaces = none gases = none elements = none

suffix _1

 

go

 

pickup fluid

suffix _2

go