the mining process that is recovery of metals from its ore by the use of microorganisms.

1. Presented by
Nishanth S
2016601106

2. Introduction
Traditional ways of mining:
Excavation
Crushing
Smelting
Extraction of Fe, Cu & Au
Why Biomining?
Dust
Gases
Toxic compounds
1. Cheap
2. Reliable
3. Efficient
4. Safe
5. Environmentally friendly

3. The use of micro-organisms to facilitate the extraction and
recovery of precious and base metals from primary ores and
concentrates, referred to generically as ‘biomining’, has developed
into successful and expanding area of biotechnology.
Simply,
1. Extracting mineral ores
2. Enhancing the mineral recovery
Copper - first metal extracted using microorganisms
Rio Tinto mines in Spain 1752.
Biomining
Rawlings & Johnson (2007)
Rossi (1990)

4. BIOLEACHING / BIO-OXIDATION
How this could be possible!!!
Extraction of metals Removal of constituents
Mediated by microbial enzymes Metabolite formed by the MO’s
Oxidases/Reductases Organic / Inorganic acids

5. Biomining Recovery
DIRECT INDIRECT
T. ferroxidans & T. thioxidans
Desulfovibro desulfuricans

6. Characteristics of organisms
Process involved Character
1. Production of high
temperatures
THERMOPHILIC
2. Strong acids and alkalis CHEMOPHILIC
3. Produce energy from inorganic
compounds
AUTOTROPHIC
4. Attachment BIOFILMS
Examples:
Thiobacillus ferrooxidans - Chemophilic, Moderately thermophilic, Produce
energy from oxidation of inorganic compounds like sulfur and iron.
Thermothrix thiopara - extremely thermophilic 60-75C - extraction of sulfur
Sulfolobus acidocaldarius
S. brierleyi

7. Factors affecting biomining
Crystal lattice energy
Surface Area
High temperature
Acid concentrations
High concentration of heavy metals
Mechanical stability
Degree of solubility
CL inversely proportional to solubility
Smaller the size higher the recovery
Concentration of sulphides
Amount of mineral content
Extent of contamination
Ore composition
Choice of bacteria

8. Factors affecting biomining
TemperatureAcidity
Aeration
Solid-Liquid ratio Surfactants
pH 2.5 – 5.3
Mesophilic / Thermophilic
25-35C
Aerobic

9. Stirred Tank Biomining
Bioheaps
In –situ biomining
Types of Biomining

10. Stirred tank biomining
Leaching from substrates with
high mineral concentration
Types of Biomining
Expensive
Time consuming
Copper and refractory gold ores
Thiobacillus is commonly used

11. Bioheaps
CRUSHING
Acid treatment
Agglomeration
Water treatment
Breakdown into small particles
Growth & multiplication of chemophilic
bacteria
Finner particles attached to the coarse ones
Optimization of moisture content
Height: 2- 10 feet
with altering tubes for air supply
biopiles/ biomounds/ biocells

12. Biomining of Copper
COPPER ORE
Water & Sulphuric acid trt
Leach solution
Lead/Graphite
Cu
C A
Aluminium
- +
Cu
Cu
Cu
Cu
Cu
Cu
Cu
Cu
CuCu Cu
Cu
Cu
Cu
Cu
Cu
Cu
Cu Cu
Cu
Cu
Cu
Cu
Cu
Cu
Organic extractant Highly acidic electrolyte
Leach solution
Electrowinning

13. 1. http://biologywriteup.blogspot.in/2014/10/biomining-use-of-
microbes-biomining.html
2. Agate, A D. 1996. Recent Advances in Microbial mining. World
Journal of Microbiology & Biotechnology 12: 497-495
3. Rawlings, D.E, Johnson,D.B. 2007. The microbiology of
biomining: development and optimization of mineral-oxidizing
microbial consortia. Microbiology,153: 315–324
References