『Abstract
Meta-analysis of 173 rate measurements from 21 publications was
used to develop rate laws for chalcopyrite dissolution under environmentally
relevant conditions. Multiple linear regression analysis of 28
data for nonoxidative chalcopyrite dissolution in the presence
of O2 and Cl- produced the following
rate law:
r＝10-1.52e-28200/RT[H+]1.68
Here, r is the rate of chalcopyrite dissolution in units of mol
m-2 s-1 where the surface area is expressed
on a geometric basis. Multiple linear regression analysis of 36
data for chalcopyrite dissolution caused by reaction with Fe(III)
in the presence and absence of O2 and Cl-
produced the following rate law:
r＝101.88e-48100/RT[H+]0.8[Fe(III)]0.42
Some data were excluded from these rate law models because they
were inconsistent with the overall dataset and/or were relatively
unconstrained. There were no published rate data that could be
clearly identified as representing chalcopyrite dissolution caused
by O2 oxidation alone. although there are
numerous reports that suggest that chalcopyrite dissolution rates
are increased by the presence of Cl- in solution, the
regression models documented that the effect of Cl-
on dissolution was insignificant for this dataset. The rate laws
developed in this work are most appropriate for characterizing
chalcopyrite dissolution at low pH (≦3), and will ultimately allow
better modeling of acid, sulfate, Fe, and Cu release to the environment.』
1. Introduction
2. Background
2.1. Chalcopyrite dissolution reactions
2.2. Chemical reactors
2.3. Data quality
3. Methods
3.1. Data conversion and analysis
4. Results
4.1. Nonoxidative chalcopyrite dissolution
4.2. Chalcopyrite oxidation by Fe(III)
5. Discussion
5.1. Identifying the predominant reaction
5.2. Nonoxidative chalcopyrite dissolution
5.3. chalcopyrite oxidation by Fe(III)
5.4. Effect of Cl-
5.5. Comparison of chalcopyrite and pyrite dissolution rates
5.6. Application of rate laws
5.7. Future work
6. Summary
Acknowledgements
Appendix A. Supplementary material
References