FT-IR studies of ethyl xanthate adsorption on gold, silver and gold—silver alloys

Jaakko Leppinen; R.-H. Yoon; J. Mielczarski

doi:10.1016/0166-6622(91)80309-C

FT-IR studies of ethyl xanthate adsorption on gold, silver and gold—silver alloys

Jaakko Leppinen, R.-H. Yoon, J. Mielczarski

VTT Technical Research Centre of Finland

Virginia Tech

Research output: Contribution to journal › Article › Scientific › peer-review

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Abstract

The effect of electrochemical potential on the adsorption of potassium ethyl xanthate (KEX) on gold, silver and their alloys of different compositions has been studied in borate solutions of pH 9.2, using FT-IR reflection spectroscopy, cyclic voltammetry and X-ray photoelectron spectroscopy (XPS). The results show that (EX)₂ and AgEX are the oxidation products formed on pure gold and silver, respectively. Both voltammetry and IR reaction spectroscopy show that the onset of these oxidation reactions occurs near the reversible potentials for the EX⁻/(EX)₂ and EX⁻/AgEX couples. On gold-silver alloys, AgEX is formed first during the anodic scan, followed by (EX)₂ formation. The potential at which xanthate is oxidized is reduced significantly, depending on the amount of silver present in a gold—silver alloy. Thus, the presence of silver in gold allows the xanthate flotation to be achieved at lower potentials than with pure gold. Both the IR and XPS spectra show evidence for the formation of unknown surface species at low potentials.

Original language	English
Pages (from-to)	189-203
Journal	Colloids and Surfaces
Volume	61
DOIs	https://doi.org/10.1016/0166-6622(91)80309-C
Publication status	Published - 1991
MoE publication type	A1 Journal article-refereed

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@article{3c4c7b3a9f984e05a047fed1baa55689,

title = "FT-IR studies of ethyl xanthate adsorption on gold, silver and gold—silver alloys",

abstract = "The effect of electrochemical potential on the adsorption of potassium ethyl xanthate (KEX) on gold, silver and their alloys of different compositions has been studied in borate solutions of pH 9.2, using FT-IR reflection spectroscopy, cyclic voltammetry and X-ray photoelectron spectroscopy (XPS). The results show that (EX)2 and AgEX are the oxidation products formed on pure gold and silver, respectively. Both voltammetry and IR reaction spectroscopy show that the onset of these oxidation reactions occurs near the reversible potentials for the EX−/(EX)2 and EX−/AgEX couples. On gold-silver alloys, AgEX is formed first during the anodic scan, followed by (EX)2 formation. The potential at which xanthate is oxidized is reduced significantly, depending on the amount of silver present in a gold—silver alloy. Thus, the presence of silver in gold allows the xanthate flotation to be achieved at lower potentials than with pure gold. Both the IR and XPS spectra show evidence for the formation of unknown surface species at low potentials.",

author = "Jaakko Leppinen and R.-H. Yoon and J. Mielczarski",

note = "Project code: MIN1503",

year = "1991",

doi = "10.1016/0166-6622(91)80309-C",

language = "English",

volume = "61",

pages = "189--203",

journal = "Colloids and Surfaces",

issn = "0166-6622",

publisher = "Elsevier",

}

TY - JOUR

T1 - FT-IR studies of ethyl xanthate adsorption on gold, silver and gold—silver alloys

AU - Leppinen, Jaakko

AU - Yoon, R.-H.

AU - Mielczarski, J.

N1 - Project code: MIN1503

PY - 1991

Y1 - 1991

N2 - The effect of electrochemical potential on the adsorption of potassium ethyl xanthate (KEX) on gold, silver and their alloys of different compositions has been studied in borate solutions of pH 9.2, using FT-IR reflection spectroscopy, cyclic voltammetry and X-ray photoelectron spectroscopy (XPS). The results show that (EX)2 and AgEX are the oxidation products formed on pure gold and silver, respectively. Both voltammetry and IR reaction spectroscopy show that the onset of these oxidation reactions occurs near the reversible potentials for the EX−/(EX)2 and EX−/AgEX couples. On gold-silver alloys, AgEX is formed first during the anodic scan, followed by (EX)2 formation. The potential at which xanthate is oxidized is reduced significantly, depending on the amount of silver present in a gold—silver alloy. Thus, the presence of silver in gold allows the xanthate flotation to be achieved at lower potentials than with pure gold. Both the IR and XPS spectra show evidence for the formation of unknown surface species at low potentials.

AB - The effect of electrochemical potential on the adsorption of potassium ethyl xanthate (KEX) on gold, silver and their alloys of different compositions has been studied in borate solutions of pH 9.2, using FT-IR reflection spectroscopy, cyclic voltammetry and X-ray photoelectron spectroscopy (XPS). The results show that (EX)2 and AgEX are the oxidation products formed on pure gold and silver, respectively. Both voltammetry and IR reaction spectroscopy show that the onset of these oxidation reactions occurs near the reversible potentials for the EX−/(EX)2 and EX−/AgEX couples. On gold-silver alloys, AgEX is formed first during the anodic scan, followed by (EX)2 formation. The potential at which xanthate is oxidized is reduced significantly, depending on the amount of silver present in a gold—silver alloy. Thus, the presence of silver in gold allows the xanthate flotation to be achieved at lower potentials than with pure gold. Both the IR and XPS spectra show evidence for the formation of unknown surface species at low potentials.

U2 - 10.1016/0166-6622(91)80309-C

DO - 10.1016/0166-6622(91)80309-C

M3 - Article

SN - 0166-6622

VL - 61

SP - 189

EP - 203

JO - Colloids and Surfaces

JF - Colloids and Surfaces

ER -

FT-IR studies of ethyl xanthate adsorption on gold, silver and gold—silver alloys

Abstract

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