Hello, I am trying to calculate the amount of acid/base needed to achieve a specific pH in a single mineral slurry. Empirical measurement shows that at my solution/solid ratio, a pH 9, 10 mM NaCl solution added to the mineral albite resulted in a final pH of around 4.5 (I wanted it to stay around 9). Can anyone suggest a way to do this in GWB? It can be done empirically, but would be nice to be able to calculate, given the many different pH conditions I need to achieve. I do have information about surface area of my phases (albite being just one of them). BTW, the experiments I am designing would be permanently closed to atmosphere, so equilibration with CO2 would not need to be considered.
I only want to consider acid-base exchange with the mineral surface, in other words--not allowing dissolution or precipitation of other phases.
thanks in advance for any help with this, andrea