A XANES study of Cu speciation in high-temperature brines using synthetic fluid inclusions

A synthetic fluid inclusion study of copper solubility in hydrothermal brines from 525 to 725°C and 0.3 to 1.7GPa

“…Various attempts to identify the precipitated mineral (nantokite) using PIXE and Raman spectroscopy were unsuccessful because it invariably decomposed under the incident beam. However, XANES spectroscopic data were acquired confirming it as nantokite (Berry et al, 2006). It is worth noting that the appearance of nantokite is similar to triangular opaque daughter minerals found in many natural inclusions that are usually identified as chalcopyrite, but that chalcopyrite does not decompose under the incident beam (our experiments do not contain sulfur or iron, so the daughter mineral observed here can not be chalcopyrite).…”

“…The absence of Cu 2+ at high T was confirmed by XANES microspectroscopy on individual homogenised fluid inclusions from this study (Berry et al, 2006). The small amounts of capsule solution that could not be extracted turned greenish-blue after exposure to air.…”

“…At constant P and T, pH and a HCl 0 ðaqÞ are fixed according to the amount [Cl] t in the experimental solution. The coexistence of native copper and cuprite buffers the redox potential of the system, via 2Cu + H 2 O = Cu 2 O + H 2 , such that copper(I) is the oxidation state in the experimental solutions, and has been confirmed by XANES spectroscopy on homogenised fluid inclusions (Berry et al, 2006).…”

The controls of post-entrapment diffusion on the solubility of chalcopyrite daughter crystals in natural quartz-hosted fluid inclusions

“…This is likely to be due to the preferential complexation of Cu as highly soluble CuCl 0 and [CuCl 2 ] -species as proposed in a number of solubility Holland, 1984, 1986;Bai and Koster van Groos, 1999;Archibald et al 2002;Simon et al, 2006) and speciation studies (Mavrogenes et al, 2002;Berry et al, 2006Berry et al, , 2009. Despite this, Cu concentrations were also commonly elevated in several low salinity (<2.0 wt.% NaCl eq ), liquid or vapor inclusions at El Teniente (Vry, 2010 (Heinrich et al 1999;Mountain and Seward, 2003;Simon et al, 2006;Pokrovski et al, 2008;Seo et al, 2009;Landtwing et al, 2010).…”

Structural behaviour of copper chloride catalysts during the chlorination of CO to phosgene

“…This is forbidden for Cu + species. 30 Apart from the pre-edge feature, Kau et al 31 observed no other signicant peaks below 8985 eV for any Cu 2+ species. However, for Cu + species, a sharp feature below the dashed line in Fig.…”