Thiocyanate Hydrometallurgy For the Recovery of Gold Part V: Process Alternatives For Solution Concentration and Purification

Editor(s)

Petersen, Jochen

Abstract

The gold-thiocyanate system is of interest as it could offer a number of advantages over the gold-cyanide system such as acidic leaching and less toxicity. In the gold-thiocyanate system, the rate of leaching can be accelerated by employing ferric ion as an oxidant. Ultimately, this would lead to a contaminated gold-bearing leach solution that would need to be treated. In this regard, process alternatives for solution concentration and purification are considered including solvent extraction, cementation, and carbon adsorption. The effect of ferric ion on the extraction and stripping of gold was studied. It was demonstrated that ferric ion has an adverse effect on the rate of gold stripping with thiourea. This situation was overcome by controlling the system chemistry-relatively low SCN concentration (0.02 M) in aqueous phase and low amine concentration (0.01-0.02 M) in the organic phase. Strategies other than solvent extraction including cementation with iron and zinc as well as activated carbon adsorption were considered and results reported. Finally, based on this study a conceptual flowsheet is given for the recovery of gold through thiocyanate hydrometallurgy.

Department(s)

Materials Science and Engineering

Keywords and Phrases

Thiocyanate; Alamine 336; Gold; Ferric Iron; Stripping; Solvent Extraction; Cementation; Carbon Adsorption

International Standard Serial Number (ISSN)

0304-386X

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2012 Elsevier, All rights reserved.

Publication Date

01 Feb 2012

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