This Powepoint introduced the applications of BioTechnology & Microbiology in Flotation.

1. University of Tehran
Collage of Engineering
School of Mine
By: Sina Ghassa
Advisor: Professor Gharabaghi
December 2013

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Cultivation of bacteria
Bacteria
Classifications
Bio-flotation
Fundamentals
Bio-flotation
Applications

3. BACTERIA CLASSIFICATION (FEEDING)
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Autotrophic Bacteria
Use atmosphere CO2 as Carbon resource
Use ammoniac as Nitrogen resource
Heterotopic Bacteria
Farina, Glucose, and other nutrient have to
added to cultures
Bacteria could Classified based on:
Feeding Requirements
Shape
Living Temperature

4. BACTERIA CLASSIFICATION (SHAPE)
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Bacillus (A)
Spirillum (B)
Cocci (C)
(B)
(C)

5. BACTERIA CLASSIFICATION (TEMPERATURE )
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Mesophil
25-45 C
Acidobacillus Ferrooxidans, Acidobacillus
thiooxidans, Leptospillirum Ferrooxidans
Moderate Thermophile
45-65 C
Most of them are heterotrophic bacteria
Thermophile
65-85 C
Sulfolobus
Extremely Thermophile
Upper than 85 C

6. CULTIVATION OF BACTERIA
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 Steps
1. Enrichment Step
2. Separation Step
3. Purification Step
 Culture Media
1. Solid culture
2. Liquid

7. CULTURE MEDIA
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D1D2LeathenNorrisHP0.9K9K
(NH4)SO4
MgSO4. 7H2O
K2HPO4
--KCl
-----Ca (NO3)2. H2O
Elemental Sulfur or Ferric could be added to media as nutrient
Culture Media Compositions

8. CULTIVATION OF BACTERIA
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9. A BACTERIA STRUCTURE
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10. SURFACE CHANGES
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The surface changes of sphalerte particle in contact
with bacteria (Ghassa et al. 2014)

11. BIO-FLOTATION
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The Bio-Flotation have been used to reduce the using chemical
reagents to reduce the environmental impacts and
microorganisms selectivity
Bacteria could be used as:
Flotation depressants
Collectors
Dispersing agent
Flocculate

12. MECHANISMS
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There are three different mechanisms by means of which the
biomodification can occur:
attachment of microbial cells to the solid substrate
oxidation reactions
adsorption and/or chemical reaction with the metabolite products
(EPS).

13. BACTERIA ADHESION
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The bacterial adhesion occurs as a net result of
attractive and repulsive forces of the cell and mineral
surfaces. The interactions that result in such adhesion
include electrostatic interactions, acid–base
interactions, van der Waals forces and hydrophobic
interactions, all of which are determined by the cell-wall
and mineral surface properties (Merma et al. 2013)

14. DEPRESSANTS
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The selective flotation separation of cinnabar from
antimonite has been carried out by Lyalikova & Lyubavina
(1986) using A. ferrooxidans. They suggested that
antimonite was oxidized by the bacteria, leading to its
depression, while cinnabar was not affected.
It was found that galena was totally depressed in the pH
range of 5-11 after bacterial interaction, while the flotation
recovery of sphalerite was not affected. The significant
differences in the adsorbabilities of the bacterial cells onto
galena and sphalerite coupled with the nature of the
interaction products, be it the respective sulfates or
hydroxides,

15. PYRITE DEPRESSANTS
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Cyanide have been used extensively as Pyrite Depressants in
flotation processes
In the presence of A.thiobacillus Ferrooxidans, and xanthate
as collector, pyrite was depressed(40%),whereas chalcopyrite
and other sulfide minerals were unaffected at natural pH
(Hosieni et al., 2005)
The Pyrite recovery in presence of A.thiobacillus Ferrooxidans
was 8% during Galen concentrating (Mehrabani et al., 2011)
During Sphalerite concentrating the pyrite recovery is 23.52 %.

16. COLLECTOR
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 Bacillus subtilis and Mycobacterium phlei function as
collector in anionic collector flotation of dolomitic
phosphate ores, while Bacillus subtilis functions as the
stronger collector, especially for dolomite
 The interaction of P. polymyxa with calcite, hematite,
corundum, kaolinite and quartz resulted in the quartz
and kaolinite surfaces being rendered more
hydrophobic

17. BIO-FLOCCULATION
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 Mycobacterium phlei was able to flocculate phosphate
slimes, hematite and coal (Smith et al., 1991)
 Produce extracellular polymers and surfactants under
certain conditions, which can cause flocculation of the
microorganisms themselves or of other solids

18. REFERENCES
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Donati, E. R., 2007. Microbial Processing of metal sulfides, Springer
Hosseini, T.R., Kolahdoozan, M.,. Tabatabaei, Y.S.M, Oliazadeh, M.,
Noaparast, M., Eslami, A., Manafi, Z., Alfantazi. A., 2005. Bioflotation of
Sarcheshmeh copper ore using Thiobacillus Ferrooxidans bacteria. Minerals
Engineering 18, 371–374
Mehrabani, J.V., Mousavi, S.M., Noaparast, M. 2011. Evaluation of the
replacement of NaCN with Acidithiobacillus ferrooxidans in the flotation of
high-pyrite, low-grade lead–zinc ore. Separation and Purification Technology
80, 202–208
Subramanian, S., Santhiya, D., Natarajan, K.A. 2003. Surface modification
studies on sulphide minerals using bioreagents. Int. J. Miner. Process. 72,
175– 188
Farahat, M., Hirajima,t., Sasaki, K., Aiba, y., Doi, K., 2008. Adsorption of SIP
E. coli onto quartz and its applications in froth flotation. Minerals Engineering
21, 389–395

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SINA GHASSA
University of Tehran
December 2013