Experimental investigation of the hydrothermal geochemistry of platinum and palladium: I. Solubility of platinum and palladium sulfide minerals in NaCl/H2SO4 solutions at 300°C

Gammons, Christopher H.; Bloom, Mark S.; Yu, Yinghua

doi:10.1016/0016-7037(92)90003-2

Cited by 130 publications

(63 citation statements)

References 56 publications

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“…It was shown that Pt is transported as chloride species under specific conditions of acid solutions with high oxidizing potential. These conclusions were supported then by the experimental data for 100-300°C range at water saturated vapor pressure (Gammons et al, 1992;Gammons, 1995Gammons, , 1996. In contrast to the relative wealth of low-temperature data, there have been only few experimental studies of the Pt solubility at higher temperatures.…”

Section: B Aphanas'evamentioning

confidence: 82%

Experimental Study of Gold and Platinum Solubility in a Complex Fluid under Hydrothermal Conditions

et al. 2000

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: The solubility of gold was studied in water and aqueous NaCl (1– 5 m) solutions under oxygen and sulfur buffered conditions between 300–500C at a constant pressure 1 kb. Two buffer assemblages HMP and PPM were used. Analysis of the scatter in measured values in log mAu–mNaCl–T frame fixed linear dependence between log mAu and T at any studied iso‐pleth (mNaCl) in the form of log mAu = a. T(C) + b. Coefficients of the equation were calculated for water and NaCl (1, 3, 5 m) solutions. The maximum solubility characterizes the NaCl‐free system in the presence of HMP. In the case, Au solubility increases from (log mAu) –6. 72 to –5. 04 at 300 and 500C, respectively. In the presence of PPM, maximum of Au solubility was obtained for the 5 mNaCl solution. In a similar manner solubility rises from –6. 54 to –5. 77 at 300 and 500C, accordingly. In studied fO2/fS2 area the behavior of Au solubility testified that: (i) – a composite interaction between chloride and hydrosulfide speciation of gold affects its total solubility; (ii) – in addition of NaCl up to about 1. 5 m the solubility decreases, more pronounced in the presence of HMP; (iii) – the contribution of chloride in total Au solubility is more for PPM despite of lower fO2value, than for HMP. The solubility of platinum was studied in the Pt–Cl–S–H2O system between 300 and 500C, 1 kb. PPM solid buffer controlled oxidation state, pH and sulfur activity of solutions (H2O, 1 mNaCl and 0. 1 mHCl). Under the conditions, PtS precipitated from the solutions with increasing temperature and acidity. The PtS solubility in the 0. 1 mHCl solutions lowers slightly in the range of 300–500C from –5. 30 to –5. 60 (in log mPt) that is typical to the hydrosulfide species. It was deduced that reducing media, regulated by the PPM assemblage, suppress activity of chloride species of Pt. More oxidizing conditions were modeled in runs using mixtures of Mn(II), Mn(III) and Mn(IV) oxides to buffer the aqueous‐chloride solutions between 300 and 500C, 1 kb. It was found that MnO tends to oxidize at T below 400C forming intermediate Mn‐hydroxides (β–MnOOH, Mn (OH)2 and Mn2(OH)3Cl). These phases are metastable and transfer to Mn3O4 with increasing duration. Generation of the Mn‐hydroxides leads to a change of physical‐chemical parameters of the solutions, such as water activity, pH and Eh. The last results in abrupt increase in the noble metals dissolution. At stable existence of only Mn3O4, the solubility of both Pt and Au lowers to equilibrium values. Essential catalysis effect of Pt on intensity and rate of Mn(II) oxidation was found. The dominant role of chloride of Pt and Au was defined under most oxidized conditions, specified by Mn2O3–MnO2 buffer. So at 400C, dissolved Au (log mAu) increases from –4. 40 in water to –1. 00 in 0. 1 mHCl, and ones of Pt (log mPt) from –4. 80 to –2. 90 accordingly. Thus, mixing of hydrosulfide and chloride solutions, as well as transformation of the systems to the stable state act upon total solubility of the noble metals.

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Section: B Aphanas'evamentioning

confidence: 82%

Experimental Study of Gold and Platinum Solubility in a Complex Fluid under Hydrothermal Conditions

et al. 2000

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“…The relative enrichment of Pt and Pd in the altered rocks and the ores, which are themselves altered sedimentary rocks, suggest that the reacting hydrothermal solution was enriched in (Barnes et al, 1985;Mountain and Wood, 1988;Gammons et al, 1992;Farrow and Watkinson, 1997). It is interesting to note here that the carbonaceous bed of the Zimudang deposit is significantly enriched in Pd.…”

Section: Resultsmentioning

confidence: 99%

Geochemistry of the sediment-hosted disseminated gold deposits in Southwestern Guizhou Province, China /

Bao¹

2001

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“…Pan & Wood 1994;Economou-Eliopoulos 2005;Hanley 2005;Hanley et al 2005). At the conditions of amphibolite facies alteration in the Longwood rocks, it would be expected that PGE and Au are capable of mobility via bisulfide complexes (Gammons et al 1992;Pan & Wood 1994;Seward & Barnes 1997). Consequently, at least some of the PGE inventory in the Longwood rocks could be related to the later imposition of hydrothermal fluid flux, related alteration, and structural control.…”

Section: Alterationmentioning

confidence: 99%

Mafic and ultramafic rocks, and platinum mineralisation potential, in the Longwood Range, Southland, New Zealand

Ashley

Craw

MacKenzie

et al. 2012

New Zealand Journal of Geology and Geophysics

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Intrusive rocks in the Longwood Range represent a component of the Permian Brook Street Terrane. They include diffusely layered, cumulate-textured olivine gabbro, troctolite, and gabbro, and gradations into non-cumulate gabbro and gabbronorite. Volumetrically small ultramafic layers occur (plagioclase wehrlite), and thin veins of felsic rocks ranging from quartz diorite to trondhjemite. Primary olivine, plagioclase, clinopyroxene, and subordinate orthopyroxene and hornblende are commonly altered or metamorphosed to amphiboles, minor spinel, magnetite, chlorite, biotite and clinozoisite, and serpentine in olivinerich rocks. Accessory primary Ti-bearing magnetite and ilmenite occur, and trace Cr-magnetite is characteristic of olivine-rich rocks. Trace pyrrhotite, chalcopyrite, pentlandite, and pyrite could reflect equilibrated late magmatic, and alteration-derived phases. Key petrochemical characteristics of the rock suite are high Mg, Al, Ca, and Sr contents, and low alkali, LILE, and sulfur contents. Platinum and Pd are locally enriched in drill-hole intercepts, but zones appear unrelated to rock type, magnetic properties, or to S, Cu, Ni, Cr, or Au values. Local platinum group element (PGE) enrichment in altered rocks implies metamorphic and/or hydrothermal redistribution. Pervasive PGE enrichment in Longwood rocks is an indicator of potential 'fertility', but evidence is currently lacking for the precipitation of primary stratiform PGE accumulations from a sulfide liquid saturated magma.

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Experimental investigation of the hydrothermal geochemistry of platinum and palladium: I. Solubility of platinum and palladium sulfide minerals in NaCl/H2SO4 solutions at 300°C

Cited by 130 publications

References 56 publications

Experimental Study of Gold and Platinum Solubility in a Complex Fluid under Hydrothermal Conditions

Experimental Study of Gold and Platinum Solubility in a Complex Fluid under Hydrothermal Conditions

Geochemistry of the sediment-hosted disseminated gold deposits in Southwestern Guizhou Province, China /

Mafic and ultramafic rocks, and platinum mineralisation potential, in the Longwood Range, Southland, New Zealand

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