The accuracy of the geochemical model PHRQPITZ (Plummer et al., 1988), which uses the ion-interaction method (Pitzer, 1973) for the calculation of activity coefficients in predicting mineral solubilities, is evaluated. Furthermore, a method for estimating computational error in saturation indices for minerals in natural systems is developed. The published experimental solubility data for celestite (SrSO₄), barite (BaSO₄), fluorite (CaF₂), and calcite (CaCO₃) are evaluated and compared to calculated solubility data for the minerals in simple binary (mineral-H₂O) and ternary (mineral-NaCl-H₂O) systems. The solubility modeling error determined for minerals in these simple systems is then extrapolated to several examples of natural systems. The error in magnitude and direction gives a good estimate of the computational uncertainty in the mineral saturation indices calculated by PHRQPITZ for the natural systems. The only adjustment to PHRQPITZ is the addition of polynomial-based log K(sp) equations for the minerals being evaluated.
| Identifer | oai:union.ndltd.org:arizona.edu/oai:arizona.openrepository.com:10150/277912 |
| Date | January 1991 |
| Creators | Dal Pozzo, Peter Dean, 1958- |
| Contributors | Bassett, Randy L. |
| Publisher | The University of Arizona. |
| Source Sets | University of Arizona |
| Language | en_US |
| Detected Language | English |
| Type | text, Thesis-Reproduction (electronic) |
| Rights | Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author. |
Page generated in 0.0014 seconds