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2011-Sustainable Industrial Processing Summit
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Editors: | Florian K |
Publisher: | Flogen Star OUTREACH |
Publication Year: | 2012 |
Pages: | 646 pages |
ISBN: | 978-0-9879917-4-4 |
ISSN: | 2291-1227 (Metals and Materials Processing in a Clean Environment Series) |
Extractive industries play an important role in the economic development of a country. However, the mineral beneficiation processes cause various environmental problems, not only because the wastes from mining process, but also due to the use of large amounts of chemical reagents such as collectors, depressants, frothers, etc. To reduce environmental problems and the process costs, several studies have been carried out on the use of microorganisms as friendly reagents, with the purpose of replace (partial or total) traditional flotation reagents in mineral processing. The interactions of microorganisms with minerals can be direct or indirect. In the indirect interaction, the biological products act as surface-active agents and in the direct interaction occur microbial adhesion or attachment to particles bringing out surface modification. Both types alter the mineral hydrophobicity, indicating that the microorganisms can act as bioreagents through selective adhesion onto the mineral surface. Considering the literature about the use of microorganisms in mineral processing, this work leads to a basic study in the bioadhesion of R. opacus on apatite, and also to the adhesion mechanism involved in the mineral-bacteria interaction. The R. Opacus strain was obtained from the cultures collection of André Tosello Foundation, SP, Brazil. It was cultivated in a liquid medium containing: malt extract, yeast extract, peptone and glucose, at 280C. The pH of the growth medium was adjusted to 7.2 by the addition of NaOH prior to autoclaving. The sample of apatite ore used in this studied was from State of Minas Gerais/BR. All bioadhesion experiments were carried out in a duplicate run basis.