Oxidation of pentlandite and pyrrhotite surfaces at pH 9.3: Part 2. Effect of xanthates and dissolved oxygen
-
D.L. Legrand
und
H.W. Nesbitt
Abstract
Using X-ray photoelectron spectroscopy, the oxidation/alteration of massive coexisting pentlandite (Pn) and pyrrhotite (Po) from Voisey's Bay has been studied in aqueous solution at pH 9.3, with the addition of the xanthate collector potassium amyl xanthate (KAX) at varying solution O2 concentrations. As in the accompanying XPS study, the oxidation/alteration of the two mineral surfaces is monitored by the Fe 2p, Ni 2p, S 2p, and O 1s XPS spectra. The major surface product on all surfaces is FeOOH. However, the amount of FeOOH depends greatly on the presence of KAX, the presence of ground Pn/ Po of high surface area, and the O2 solution concentration. At air-saturated O2 solution concentrations of 8.9 ppm, the amount of FeOOH on both surfaces decreases in the presence of KAX compared to the situation without KAX. In the presence of the Pn/Po powder, the oxidation of Pn decreases still more, suggesting that the powder scavenges O2, and that the oxidation of Pn is more sensitive to O2 concentration than the oxidation of Po. When the O2 concentration is decreased drastically to <0.01 ppm (by Ar purging) in the presence of KAX, both minerals are relatively free of FeOOH: indeed, both minerals show less FeOOH than the unreacted sample, which implies that the mineral surfaces are being .cleaned. under these conditions. The degree of oxidation of both surfaces increases with increase in the O2 solution concentration; but at about 0.03 ppm O2 the pyrrhotite surface is heavily oxidized, while the pentlandite surface remains largely unoxidized, and less oxidized than the initial unreacted sample. This result strongly indicates that the flotation separation of Pn and Po could be enhanced at low O2 concentrations.
© 2015 by Walter de Gruyter Berlin/Boston
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- Oxidation/alteration of pentlandite and pyrrhotite surfaces at pH 9.3: Part 1. Assignment of XPS spectra and chemical trends
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Artikel in diesem Heft
- A synthesis of systematic mineralogy
- Oxidation/alteration of pentlandite and pyrrhotite surfaces at pH 9.3: Part 1. Assignment of XPS spectra and chemical trends
- Oxidation of pentlandite and pyrrhotite surfaces at pH 9.3: Part 2. Effect of xanthates and dissolved oxygen
- X-ray Rietveld refinement and FTIR spectra of synthetic (Si,Ge)-richterites
- Influence of crystal chemistry on ideal plastic shear anisotropy in forsterite: First principle calculations
- High-temperature Mössbauer study of Fe-substituted mullite
- Pressure and temperature-dependence of water solubility in Fe-free wadsleyite
- Quartz exsolution in clinopyroxene is not proof of ultrahigh pressures: Evidence from eclogites from the Eastern Blue Ridge, Southern Appalachians, U.S.A.
- The visible and infrared spectral properties of jarosite and alunite
- Wakabayashilite, [(As,Sb)6S9][As4S5]: Crystal structure, pseudosymmetry, twinning, and revised chemical formula
- Compression of albite, NaAlSi3O8
- Effect of polymorphic transition on oxygen isotope fractionation between aragonite, calcite, and water: A low-temperature experimental study
- Effect of current density on the electron microprobe analysis of alkali aluminosilicate glasses
- A high-pressure polytypic transformation in type-I chlorite
- Experimental determination of crystal growth rates in highly supercooled aluminosilicate liquids: Implications for rate-controlling processes
- P-V equation of State, thermal expansion, and P-T stability of synthetic zincochromite (ZnCr2O4 spinel)
- Niksergievite, [Ba1.33Ca0.67Al(CO3)(OH)4][Al2(AlSi3O10)(OH)2]·nH2O, a new phyllosilicate related to the surite-ferrisurite series
- The crystal-chemistry of holmquistites: Ferroholmquistite from Greenbushes (Western Australia) and hints for compositional constraints in BLi amphiboles
- Dissakisite-(La) from the Ulten zone peridotite (Italian Eastern Alps): A new end-member of the epidote group
- Mazzite-Na, a new zeolite from Boron, California: Its description and crystal structure
- Low-temperature illitization of smectite in the late eocene and early oligocene of the Isle of Wight (Hampshire basin), U.K.
- First reported sedimentary occurrence of berlinite (AlPO4) in phosphate-bearing sediments from Cioclovina Cave, RomaniaComment
- Optical and near infrared spectra of ringwoodite to 21.5 GPa: Implications for radiative heat transport in the mantle
- Letter. Observation of nano-clustered calcite growth via a transient phase mediated by organic polyanions: A close match for biomineralization
- Letter. Aluminum coordination and the densification of high-pressure aluminosilicate glasses
- Letter. Crystal chemistry of a high-pressure C2/c clinopyroxene with six-coordinated silicon
