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Hi! I'm trying to run a simulation to see how anorthite reacts with seawater in a high pCO2 environment. I want to add kinetics but when I ran the file it gets stuck on step 946 and will not progress beyond that. I've attached the relevant react file. If someone could help me with this it would be extremely appreciated! Thanks, C anorthite.sw.rea

I have read through the available documentation for React and GWB more broadly and am stumped on a topic. I want to create a complex composite rate law for Olivine (Forsterite) dissolution following Wogelius and Walthers (1991). They have a three term rate equations: Rate = 9.07e-12*activity(H+)^0.54 + 5.25e-15 + 2.33e-17*activity(H+)^-0.31 The overall rate is in units mol cm-2 s-1, so to write this complex composite rate law surface and (1-Q/K) terms are needed. None of the documentation I have read explains clearly how to do such a rate law, and you cannot add more than one kinetic mineral term in React. I suspect I just need guidance on how to format this on the command line, so insight for someone more knowledgeable than me would be appreciated.

Hi, I am trying to model calcite dissolution in DI water open to the atmosphere. My model is nearly correct except that the initial pH is only reaching about 9.6 when I need it to be reaching about 10 initially. I believe that the problem may stem from my basis fugacity of CO2 in the system. Currently it is set to log fugacity of -3.5 but since the water I use for the experiment comes from a jug, is it possible that the initial fugacity of water is lower? Or, is it possible that the fugacity of CO2 in the kinetic reaction should be set to a different value other than log fugacity of -3.5? I have tried playing with these values but was unable to achieve a higher initial pH. I have attached my expiremental results as well as my model. Let me know if you have any suggestions of how to raise the initial pH of the solution. Thank you, Robin Calcite only.rea Calcite Expiremental.xlsx

I am working on a final project in a course, and am having some difficulty interpreting the output from GWB. My input files are below. My question boils down to how geochemist workbench deals with the "time" component on the basis species page, and the "reactants times" on the reactants page when dealing with a flow-through model. I have found the residence time of a conservative tracer in my column, which is ~164 minutes. Over the course of my column experiments, which typically last ~5 days, I react ~44 pore volumes. To incorporate this information into the model, I have used both 164 minutes (residence time) and 120 hours (average experiment time). On the reactants page, I said to react 44 times. But I don't know what GWB is reacting in that case. If someone would be able to advise me on the best way to incorporate all the known data into my system, I'd appreciate any help. In the end, I want to run a series of these to see how long it takes to dissolve 15.59 cm^3 or 23 grams of silicate glass. Thanks, MC SiDiss1.rea

Hello, I’m trying to model precipitation of the uranium-bearing mineral, Swartzite (CaMg(UO2)(CO3)3•12(H2O)), from solution. When I equilibrate my ground water chemistry of interest using REACT and X1T, Swartzite is the only uranium-bearing mineral to be supersaturated (SI>0 [sI=0.45]). I’m using an updated thermodynamic database, that includes uranium data determined after the discovery of Ca2UO2(CO3)30 CaUO2(CO3)3-2and MgUO2(CO3)3-2 complexes by Bernhard in 1996. I can’t find appropriate kinetic rate constants for the precipitation and dissolution of Swartzite to include in my REACT and X1T models. I plan to include rate constants of an alternate uranium-bearing mineral in place of Swartzite, such as Schoepite or Rutherfordine if no data are available. However, such substitution will render my output a gross approximation. Has anyone determined or located reliable kinetic rate constants for Swartzite while modeling uranium mineral saturation? Has anyone been unable to find kinetic rate constants for a mineral, and ended up substituting in a similar mineral? Any help would be useful. Thanks. GWB_U_02172012.dat

​Dear forum, ​as I calculate anorthite dissolution using a custom rate law in Xt1 I wonder about the reference of the kilograms in the unit of the reaction rate (rxn rate) in the text output file of GWB, which is mol/kg sec. So my question is if the kilograms refer to one kilogram of water? Thanks for your help and kind regards, Christoph​