Solubility product constants for the calcium ferric arsenate mineral, Yukonite: Fitting possible formulas with PhreePlot

摘要

Solubility product constants, as log K_(sp) values, were estimated for several possible formulas for the calcium ferric arsenate mineral yukonite. These values used a data set of solution compositions composited from work performed at McGill University over the past 10 years. The fitting routines were performed using the program PhreePlot. Three formulas have been selected and the resultant solubility product constants were estimated based upon a review of a wide range of possible formulas. A fourth formula based upon the simultaneous fitting of the formula and log K_(sp) was also estimated. Analytical uncertainties particularly with the iron concentrations limit the application of this data set. The PhreePlot based results are comparable to other log K_(sp) values estimated using an alternative regression methodology.