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Effect of Bacteria on the Flotation
of Chalcopyrite
Wenying Liu
Centre for Water in the Minerals Industry
Sustainable Minerals Institute
The University of Queensland, Australia
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Water Challenges
Water reuseMultiple sources
Water Scarcity
Climate Variability
Water Challenges Resulting ProblemGood Water Management
Sustainability Goal
Water Competition
Community Concern
Variation
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Causes of Water Quality Variation
External Sources• Multiple sources of raw water
• External water reuse
• Climate conditions
Internal Sources• Ore
• Reagent
• Internal water reuse
A Simplified View of Mine Site Water System
Ore & ReagentInternal
Raw Water
Tailings
Facility
External Reuse
External
Worked
WaterInternal Reuse
Concentrator
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Water Constituents
Abiotic
• Meaning not alive – metal ions
Biotic
• Meaning of or related to life – organics,microorganisms
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Impact of Abiotic on Flotation
Negative Impacts
• Metal hydroxide – forming a barrier for collector
adsorption(Hoover 1980; Rao & Finch 1989)
• Salt - Formation of finer gas bubbles
(Pugh et al. 1997)
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Biological Processes in Mineral Processing
• Bioreagent
(Somasundaran et al, 1998; Nagaoka et al., 1999)
Importance of Bacteria in Conventional Flotation
Impact of Biotic on Flotation
(Levay and Schumann, 2006)
• Multiple water sources containing bacteria
(Slatter et al., 2009)
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Objectives of This Research: Biotic
Bacteria – E. coli Mineral - Chalcopyrite
Quantify effect of bacteria on mineral flotation
Flotation
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Microflotation Experiment
Experimental Setup
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r i t e F l o t a t i o n
Y i e l d ,
%
40
60
80
100
Baseline Test
Flotation without E. coli
Collector (Sodium Ethyl Xanthate), mg/L
0.0 0.2 0.4 0.6 0.8 1.0 1.2
C h a l c o p
y
0
20
Figure 1 Chalcopyrite flotation yield as a function of collector
concentration in the absence of E. coli
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i t e F l o t a t i o n Y i e l d ,
%
40
60
80
100
Experimental Results
Flotation with E. coli
Initial E. coli Concentration, cell / ml
105 106 107 108 109
C h a l c o p
y
0
20
Figure 2 Effect of E. coli cell concentration on the flotation of chalcopyrite
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r i t e F l o t a t i o n
Y i e l d ,
%
40
60
80
100
Experimental Results
Flotation with Salt
NaCl Concentration, mg/L
0 1000 2000 3000 4000
C h a l c o p y
0
20
Figure 3 Chalcopyrite flotation yield as a function of NaCl
concentration in the absence of E. coli
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i t e F l o t a t i o n Y i e l d ,
%
40
60
80
100No NaCl
NaCl Concentration: 696 mg/L
NaCl Concentration: 1740 mg/L
NaCl Concentration: 3480 mg/L
Experimental Results
Flotation with Salt and E. coli
E. coli Concentration, cell / ml
106 107 108 109
C h a l c o p
y r
0
20
Figure 4 Effect of E. coli cell concentration on the flotation
of chalcopyrite at different NaCl concentrations
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i t e F l o t a t i o n Y i e l d ,
%
40
60
80
100
No Collector
0.3 mg/L
0.6 mg/L
1 mg/L
Experimental Results
Increase Collector Concentration
Initial E. coli Concentration, cell/ml
106 107 108 109
C h a l c o p
y r
0
20
Figure 5 Effect of E. coli cell concentration on the flotation
of chalcopyrite at different collector concentrations
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Conclusions
E. coli had an adverse effect on chalcopyrite flotation;
More pronounced effect in the presence of NaCl;
Increasing collector concentration could only partially
miti ate the adverse effect.
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Acknowledgement
My supervisors Chris Moran, Sue Vink and Yongjun Peng
Staff and students in Sustainable Minerals Institute
ARC Linkage and AMIRA P260E
Scholarship from the University of Queensland, Australia