Mismatch between multiple analysis and manual input

[MEEM]

Hello,

 

I'm trying to run multiple saturation index analyses for the first time in SpecE8 in version 7.0. I've managed to adapt the calcite example to work for my data and it will run (Jarosite script attached), however the mineral SIs reported in the ouput file are different than those calculated if I manually input the data into SpecE8 (jarosite basis attached). The differences are small if I run the model at 25 C, but become very significant at T=50.

 

Can anyone point me towards a solution or explanation?

 

Many thanks!

Megan

Jarosite Script.sp8

jarosite basis.sp8

[Tom Meuzelaar]

Hello,

 

I'm trying to run multiple saturation index analyses for the first time in SpecE8 in version 7.0. I've managed to adapt the calcite example to work for my data and it will run (Jarosite script attached), however the mineral SIs reported in the ouput file are different than those calculated if I manually input the data into SpecE8 (jarosite basis attached). The differences are small if I run the model at 25 C, but become very significant at T=50.

 

Can anyone point me towards a solution or explanation?

 

Many thanks!

Megan

 

Hi Meghan:

 

Your jarosite script calls 'jarosite.txt' as input file- would you mind attaching this?

 

Regards,

 

Tom Meuzelaar

 

RockWare, Inc.

[MEEM]

Here is the Jarosite.text input file (attached)

Jarosite.txt

[Tom Meuzelaar]

Here is the Jarosite.text input file (attached)

 

Hi Meghan:

 

I believe the problem is that the default concentration units for the Tcl script input files are mg/kg (see the Multiple Analyses appendix in the v7 Reference manual). So you'll need to convert.

 

Let me know if that resolves the issue.

 

Regards,

 

Tom

[MEEM]

Tom-

 

Tom, thanks for catching the units error. I fixed the script (attached below) to read the values as molal and that greatly improves the situation, but the values produced manually still do not replicate the values reported via the script.

 

For example, the "manual" model yields

Hematite 3.7604s/sat

Goethite 1.3588s/sat

Jarosite-K -2.5521

Fe(OH)3(ppd) -2.7895

 

While the script yields

Hematite 3.187

Goethite 1.072

Jarosite-K -3.295

Fe(OH)3(ppd) -3.077

 

For the first set of conditions in the jarosite.txt file. Any ideas??

Jarosite Script 2.sp8

[Tom Meuzelaar]

Hi Meghan:

 

Your single script does not balance for charge, while your Tcl script does.

 

If you remove the line...

 

balance on Cl-

 

..from the Tcl script, the output matches that of the initial script.

 

Regards,

 

Tom Meuzelaar

RockWare, Inc.

[MEEM]

Thanks- mystery solved!