Document Type

Article

Publication Date

6-20-2014

Keywords

bioleaching, chemoorganotrophic, fungi, bacteria, olivine, nickel, ultrasonic treatment, mineral carbonation

Abstract

Bioleaching of olivine, a natural nickel-containing magnesium-iron-silicate, was conducted by applying chemoorganotrophic bacteria and fungi. The tested fungus, Aspergillus niger, leached substantially more nickel from olivine than the tested bacterium, Paenibacillus mucilaginosus. Aspergillus niger also outperformed two other fungal species: Humicola grisae and Penicillium chrysogenum. Contrary to traditional acid leaching, the microorganisms leached nickel preferentially over magnesium and iron. An average selectivity factor of 2.2 was achieved for nickel compared to iron. The impact of ultrasonic conditioning on bioleaching was also tested, and it was found to substantially increase nickel extraction by A. niger. This is credited to an enhancement in the fungal growth rate, to the promotion of particle degradation, and to the detachment of the stagnant biofilm around the particles. Furthermore, ultrasonic conditioning enhanced the selectivity of A. niger for nickel over iron to a value of 3.5. Pre-carbonating the olivine mineral, to enhance mineral liberation and change metal speciation, was also attempted, but did not result in improvement as a consequence of the mild pH of chemoorganotrophic bioleaching.

Comments

12 April 2016: At the time of publication, Sheridan College author Rafael Santos was associated with Katholieke Universiteit Leuven in Belgium.

Faculty

Faculty of Applied Science & Technology

School

School of Chemical and Environmental Sciences

Version

Publisher's version

Peer Reviewed/Refereed Publication

yes

Terms of Use

Terms of Use for Works posted in SOURCE.

Original Publication Citation

Chiang, Y. W., Santos, R. M., Van Audenaerde, A., Monballiu, A., Van Gerven, T., & Meesschaert, B. (2014). Chemoorganotrophic bioleaching of olivine for nickel recovery. Minerals, 4(2), 553-564. doi:10.3390/min4020553

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