The effects of milling and ph On Co, Ni, Zn and Cu bioleaching from polymetallic sulfide concentrate
Year of publication
2021
Authors
Mäkinen, Jarno; Heikola, Tiina; Salo, Marja; Kinnunen, Päivi
Abstract
Acid bioleaching of a low-grade and polymetallic sulfide concentrate was studied, in order to determine suitable feed material particle size and pH for efficient leaching of valuable metals. The sulfide concentrate consisted of pyrite (50 wt %), pyrrhotite (31 wt %), quartz (10 wt %) and lower amounts of cobalt, nickel, zinc and copper (each <1 wt %). After adaptation of microorganisms in shake flasks, stirred tank tests were conducted at different pH levels and supplementing feed material at different particle sizes (milled to d80 < 150 µm, <50 µm, <28 µm, <19 µm). The operation at pH 1.8 was seen prone to iron precipitation, while this was not observed at a pH between 1.3 and 1.5. Additional milling to decrease particle size from the initial d80 < 150 µm had a major positive effect on cobalt-and nickel-leaching yields, proposing that at least d80 < 28 µm should be targeted. The best leaching yields for the main economic elements, cobalt and nickel, were 98% and 94%, respectively, reached with d80 < 19 µm at pH 1.3. However, it was considered that at pH 1.5, similar results could be obtained. This research sets the basis for continuing the experiments at a continuous pilot scale.
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Publication type
Publication format
Article
Parent publication type
Journal
Article type
Original article
Audience
ScientificPeer-reviewed
Peer-ReviewedMINEDU's publication type classification code
A1 Journal article (refereed), original researchPublication channel information
Open access
Open access in the publisher’s service
Yes
Open access of publication channel
Fully open publication channel
License of the publisher’s version
CC BY
Self-archived
No
Other information
Fields of science
Geosciences; Environmental engineering
Keywords
[object Object],[object Object],[object Object],[object Object],[object Object]
Language
English
International co-publication
No
Co-publication with a company
No
DOI
10.3390/min11030317
The publication is included in the Ministry of Education and Culture’s Publication data collection
Yes