[OLD] Problems running React

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From: Ben Rees

Subject: Problems running React

Attached is a .rea file I have just tried to run within React as I want to assess mineral saturation states. The data is from a laboratory leach experiment of some rock to simulate one-off leaching / rinsing. Chloride was not analysed and so I have set Cl as charge balance. Also, there is no sulphate detected. When I try to run the model it states that O2(aq) needs to be specified and also the programme would still not run as residuals were too large at the 673th iteration. I have tried adding oxygen and balancing on sulphate instead but I still can not get the model to run.

 

# React script, saved Fri May 30 2003 by Ben Rees

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

temperature = 25

swap Cr+++ for CrO4--

1 kg free H2O

total mg/l Al+++ = .005

total mg/l Sb(OH)3(aq) = .000425616

total mg/l H2AsO4- = .000752376

total mg/l Ba++ = .00777

total mg/l B(OH)3(aq) = .514606846

total mg/l Ca++ = 17.6

total mg/l Cu++ = .0094

total mg/l Mg++ = 4.2

total mg/l Mn++ = .00847

total mg/l SiO2(aq) = 7.29465646

total mg/l MoO4-- = .000133367

total mg/l Sr++ = .0898

pH = 8.19

total mg/l HCO3- = 77.531

total mg/l Cr+++ = .0019

 

From: Craig Bethke

Subject: Re: Problems running React

I assume from the input you attach that your sample contains trivalent instead of hexavalent chromium. In this case, you need to decouple Cr+++ from CrO4--, not swap these species. This eliminates the need to have O2(aq) in the system. Second, your input is overbalanced already with anions, so React cannot charge balance on Cl-. If you balance on HCO3-, the predominant anion, I think your input will converge easily.