Halite reaction kinetics

[Andrew Wigston]

Hi,

I am using GWB 2021 to investigate the potential for halite to form in a brine used for a geothermal project. The brine is extremely saline (~340,000 mg/L). So far I have only used an equilibrium approach. I am interested in incorporating kinetics just to see the effect. I understand that halite is a very fast reacting mineral.

I am using React. In the Reactants pane, I require values for rate constant (or preexp and activation energy) and surface area (and others that are to be set by me).

I have only been able to find a rate constant for halite (link below). The log k is -0.21 mol * m^-2 * s^-1 at 25C (which I calculate, for the purposes of matching the units required in GWB's React, is 6.17 x 10^-5 mol * cm^-2 * s^-1). I know that React can calculate a temperature-variable rate constant if I provide the program with values for the pre-exponential and activation energy parameters. However, the reference below only provides the rate constant and activation energy.

https://pubs.usgs.gov/of/2004/1068/pdf/OFR_2004_1068.pdf

But, I can't find any info on the surface area.

Does anyone have a reference that has this info or any insights? I understand that the duration of the simulation is important (as set on the Basis pane). I'm not sure how long the brine would be in circulation in the system, but I think it is likely on the order of minutes to tens of minutes.  The temperature change would be around 125C to around 60C.

Thanks,

Andrew