Effect of alkaline type in controlling interfacial chemistry, rheology and leaching behaviour of gold concentrates
Date
2019
Authors
Asamoah, R.K.
Addai Mensah, J.
Editors
Advisors
Journal Title
Journal ISSN
Volume Title
Type:
Conference paper
Citation
AusIMM: Metallurgical Plant Design and Operation (METPLANT) conference proceedings, 2019, pp.377-382
Statement of Responsibility
Conference Name
AusIMM: Metallurgical Plant Design and Operating Strategies (METPLANT) (9 Sep 2019 - 10 Sep 2019 : Perth, Australia)
Abstract
In this paper, the effect of alkali type in temporal rheological behaviour of refractory bio-oxidised flotation concentrate have been investigated. Generally, the results showed alkali-type dependent particle interfacial chemistry, particle leaching behaviour, pulp chemistry and rheological behaviour. The magnitudes of the zeta potentials observed were markedly low, indicative of significant electrical double layer screening. Quicklime modified bio-oxidised pulp was electropositive at high pH whilst the caustic soda modified pulps showed deprotonated particles. The predominant chemical species leached at pH 10.5 were Ca and S, independent of pH modifier. Significant back precipitation of species such as Ca and S ions were mainly observed when quicklime was deployed. This was coupled with very low leaching efficacy from the mineral ores compared with the use of sodium hydroxide. In all cases, non-Newtonian, plastic, thixotropic rheological behaviour was displayed. In addition, shear thickening and thinning behaviour were displayed by the pulps upon pH modification with quicklime and sodium hydroxide, respectively. The results suggested emergence of van der Waals and non-DLVO attractive forces such as adsorbed Ca(II) ion-particle bridging, surface nucleation and cementation for the stronger rheology of quicklime modified pulps, in contrast with caustic soda modified pulps.
School/Discipline
Dissertation Note
Provenance
Description
Access Status
Rights
Copyright 2019 AusIMM