Abstract

Bioleaching of low-grade complex sulfide ores from La Silvita and La Resbalosa (Patagonia Argentina) were carried out in a reverse flow airlift reactor by a native strain of Leptospirillum ferrooxidans (Lf-LS04). The reactor was filled with iron free 9K medium pH 1.8, with mineral particle size of – 74 μm, pulp density of 1% and a superficial air velocity of 0.01m s − 1. Zinc recoveries from the two sulfide ores – mainly in the case of La Silvita ore – were higher than those obtained previously with a collection strain of A. ferrooxidans. By applying the shrinking core-product layer diffusion model to sphalerite leaching, diffusion was found to be rate limiting due to the formation of an insoluble product layer (elemental sulfur, anglesite and ferric iron precipitates) as well as to the presence of an unreacted layer of gangue minerals (quartz, feldspar). Even in this case, the indigenous strain of L. ferrooxidans was shown to be highly efficient for processing both complex sulfides in the absence of sulfur-oxidizing bacteria.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.