Immobilization of sulfates and heavy metals in gold mine tailings by sodium silicate and hydrated lime
File(s)
Accepted version
Author(s)
Kiventerä, Jenni
Sreenivasan, Harisankar
Cheeseman, Christopher
Kinnunen, Paivo
Illikainen, Mirja
Type
Journal Article
Abstract
Gold mining produces hazardous tailings wastes with elevated sulfur content and high levels of heavy metals including oxyanion elements such as V and As. This research investigated activation of these tailings with calcium hydroxide and sodium hydroxide/sodium silicate as a way to stabilize the material and limit leaching of harmful components. The effects of thermal treatment on the reactivity of the tailings and the use of different activating solutions on the physical properties, microstructure and leaching of harmful components are reported. The effect of adding ground granulated blast furnace slag to the tailings is also assessed. The use of 5 wt % Ca(OH)2 activating solution produces optimum performance increasing the immobilization efficiency of sulfates, arsenic and the other harmful elements. Heat-treating mine tailings at 900 °C slightly improves the reactivity but did not improved the immobilization efficiency. Microstructural analysis by TEM and XRD confirmed that stabilization is based on calcium sulfate and/or ettringite formation during alkali-activation. All materials achieved reasonable compressive strength after 28 days of curing and the potential for using alkali activation as a method to treat tailings from mining is discussed.
Date Issued
2018-10-10
Date Acceptance
2018-10-06
Citation
Journal of Environmental Chemical Engineering, 2018, 6 (5), pp.6530-6536
ISSN
2213-3437
Publisher
Elsevier
Start Page
6530
End Page
6536
Journal / Book Title
Journal of Environmental Chemical Engineering
Volume
6
Issue
5
Copyright Statement
© 2018 Elsevier Ltd. All rights reserved. This manuscript is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/
Publication Status
Published
Date Publish Online
2018-10-10