Roasting temperature effect on the recovery of refractory gold and silver in pyrite concentrates

Pyrite concentrates with refractory gold and silver were roasted at different temperatures to improve the recovery of the metals by cyanide leaching. Scanning Electron Microscope characterization of the calcine revealed that the gold occluded in the pyrite less than one micron, and roasting produced...

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Bibliographic Details
Main Authors: Zhang Y.-P., Yang K., Fang Y., Robledo-Cabrera A., Peng C.-S., Lopez-Valdivieso A.
Format: Article
Language:English
Published: University of Belgrade, Technical Faculty, Bor 2021-01-01
Series:Journal of Mining and Metallurgy. Section B: Metallurgy
Subjects:
Online Access:http://www.doiserbia.nb.rs/img/doi/1450-5339/2021/1450-53392100019Z.pdf
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Summary:Pyrite concentrates with refractory gold and silver were roasted at different temperatures to improve the recovery of the metals by cyanide leaching. Scanning Electron Microscope characterization of the calcine revealed that the gold occluded in the pyrite less than one micron, and roasting produced channels in the concentrate, exposing the gold particles to the leaching solution. Gold and silver recoveries were maximum in the temperature range of 500-600°C due to the calcine high surface area and porosity. The Au and Ag recovery improved from 25 to 86% and 50 to 73%, respectively. The Au secondary encapsulation due to the sintering, the formation of the Ag-Fe-S species (Fe1−xS + Ag2S + Ag) and Ag ferrite in higher roasting temperatures hence Au and Ag recoveries decreased.
ISSN:1450-5339
2217-7175