PhreeqcUsers Discussion Forum

Mixing => Mixing Solutions => Topic started by: Sergio on May 12, 2017, 01:53:40 PM

Title: Mix sample solid
Post by: Sergio on May 12, 2017, 01:53:40 PM
Good morning everyone
Let me ask you about a mix of a sample solid and I inform the PHREQC the concentration.
My ask is: this concentration is the mass of solid that I have in my sample (20 % converted in ppm) or I have to inform the concentration of solubilized (0,2 ppm in aqueous after solubilization or leaching)).
When PHREEQC give me the answer (0,2e-3 molality) it considers the equilibrium constant or I have to inform it the constant.
thanks so much
Title: Re: Mix sample solid
Post by: dlparkhurst on May 12, 2017, 03:40:17 PM
The number of moles of a solid mineral available to react is defined in EQUILIBRIUM_PHASES.

If you then allow the EQUILIBRIUM_PHASES to react with a solution

END
USE solution 1
USE equilibrium_phase 1
END

Then the mineral will dissolve (or precipitate) to achieve equilibrium. This calculation uses the equilibrium constant for the mineral that is defined in a PHASES data block and produces the condition

K = IAP

where IAP is the ion activity product. The PHASES data block may be in the database, or you can include it in the input file.