Abstract
The resurgence of interest in transition metal isotope chemistry is the result of improved instrument precision and sensitivity. This has been achieved using multiple collector inductively-coupled mass spectrometry (MC-ICPMS) which allows simultaneous measurement of several isotope ratios in low concentrations. Copper isotope investigations have benefited from this improved technology. This study has demonstrated that appreciable Cu isotope ratio variability accompanies progressive acid ferric sulfate leaching of natural djurleite, Cu1.94S. Copper-bearing solutions from early stages of reaction (less than 10% cumulative copper dissolution) are enriched in 65Cu (δ65Cu = 1.2 ± 0.04%) compared to the initial djurleite experimental feed material (δ65Cu = -0.05 ± 0.04%). With continued reaction, 65Cu of the copper solutions steadily decreases, approaching the isotopic value of the original djurleite. As Cu:S ratio of the remaining solid material decreases, mineralogy of the residuum progresses through a series of non-stoichiometric copper sulfide phases until reaching a kinetic barrier at about 44% copper dissolution. XRD analyses has verified that the mineralogy at this boundary is dominated by the mineral yarrowite, Cu 1.12S. From djurleite to yarrowite, the average Cu-S bond length increases, resulting in an increased proportion of 4-coordinated Cu-S polyhedra over 3-coordinated geometries. This trend suggests that Cu isotope fractionation may be linked to the preference of the heavier 65Cu isotope for the lower coordinated configuration.
| Original language | English (US) |
|---|---|
| Title of host publication | IMPC 2006 - Proceedings of 23rd International Mineral Processing Congress |
| Pages | 1346-1353 |
| Number of pages | 8 |
| State | Published - 2006 |
| Event | 23rd International Mineral Processing Congress, IMPC 2006 - Istanbul, Turkey Duration: Sep 3 2006 → Sep 8 2006 |
Other
| Other | 23rd International Mineral Processing Congress, IMPC 2006 |
|---|---|
| Country | Turkey |
| City | Istanbul |
| Period | 9/3/06 → 9/8/06 |
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ASJC Scopus subject areas
- Earth-Surface Processes
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Copper isotope variability in acid ferric sulfate dissolution of natural djurleite (Cu1.94S). / Young, S. E.; Hiskey, J Brent; Ruiz, Joaquin.
IMPC 2006 - Proceedings of 23rd International Mineral Processing Congress. 2006. p. 1346-1353.Research output: Chapter in Book/Report/Conference proceeding › Conference contribution
}
TY - GEN
T1 - Copper isotope variability in acid ferric sulfate dissolution of natural djurleite (Cu1.94S)
AU - Young, S. E.
AU - Hiskey, J Brent
AU - Ruiz, Joaquin
PY - 2006
Y1 - 2006
N2 - The resurgence of interest in transition metal isotope chemistry is the result of improved instrument precision and sensitivity. This has been achieved using multiple collector inductively-coupled mass spectrometry (MC-ICPMS) which allows simultaneous measurement of several isotope ratios in low concentrations. Copper isotope investigations have benefited from this improved technology. This study has demonstrated that appreciable Cu isotope ratio variability accompanies progressive acid ferric sulfate leaching of natural djurleite, Cu1.94S. Copper-bearing solutions from early stages of reaction (less than 10% cumulative copper dissolution) are enriched in 65Cu (δ65Cu = 1.2 ± 0.04%) compared to the initial djurleite experimental feed material (δ65Cu = -0.05 ± 0.04%). With continued reaction, 65Cu of the copper solutions steadily decreases, approaching the isotopic value of the original djurleite. As Cu:S ratio of the remaining solid material decreases, mineralogy of the residuum progresses through a series of non-stoichiometric copper sulfide phases until reaching a kinetic barrier at about 44% copper dissolution. XRD analyses has verified that the mineralogy at this boundary is dominated by the mineral yarrowite, Cu 1.12S. From djurleite to yarrowite, the average Cu-S bond length increases, resulting in an increased proportion of 4-coordinated Cu-S polyhedra over 3-coordinated geometries. This trend suggests that Cu isotope fractionation may be linked to the preference of the heavier 65Cu isotope for the lower coordinated configuration.
AB - The resurgence of interest in transition metal isotope chemistry is the result of improved instrument precision and sensitivity. This has been achieved using multiple collector inductively-coupled mass spectrometry (MC-ICPMS) which allows simultaneous measurement of several isotope ratios in low concentrations. Copper isotope investigations have benefited from this improved technology. This study has demonstrated that appreciable Cu isotope ratio variability accompanies progressive acid ferric sulfate leaching of natural djurleite, Cu1.94S. Copper-bearing solutions from early stages of reaction (less than 10% cumulative copper dissolution) are enriched in 65Cu (δ65Cu = 1.2 ± 0.04%) compared to the initial djurleite experimental feed material (δ65Cu = -0.05 ± 0.04%). With continued reaction, 65Cu of the copper solutions steadily decreases, approaching the isotopic value of the original djurleite. As Cu:S ratio of the remaining solid material decreases, mineralogy of the residuum progresses through a series of non-stoichiometric copper sulfide phases until reaching a kinetic barrier at about 44% copper dissolution. XRD analyses has verified that the mineralogy at this boundary is dominated by the mineral yarrowite, Cu 1.12S. From djurleite to yarrowite, the average Cu-S bond length increases, resulting in an increased proportion of 4-coordinated Cu-S polyhedra over 3-coordinated geometries. This trend suggests that Cu isotope fractionation may be linked to the preference of the heavier 65Cu isotope for the lower coordinated configuration.
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M3 - Conference contribution
SP - 1346
EP - 1353
BT - IMPC 2006 - Proceedings of 23rd International Mineral Processing Congress
ER -