Transcript
Topics of discussion
Definition of bioleaching
Different methods of used in experiment: Acid leaching vs. Bioleaching
Purpose and general overview
Problems and solutions
Quality Control Method
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What is Metal-leaching?
Extraction of metal from ore using non traditional methods
Metallic ores contain metal sulphides.
Leaching converts metal sulfide to a metal forms which can be solubilized and filtered. 𝐅𝐞𝐒𝟐+𝟑 .𝟓𝐎𝟐+𝐇𝟐𝐎 𝑭𝒆𝟐+¿+𝟐𝑯+¿+𝟐𝑺𝑶 𝟒
𝟐−¿ ¿
What is Bioleaching?
Definition: Bioleaching is a method of metal extraction of ore with the usage of microorganisms.
Examples: Bacteria:
Paenibacillus Polymyxa Fungi :
Aspergillus nigerPenicillium simplicissimum
What is Acid Leaching
Definition: Acid leaching is a wet method of metal extraction where ore is treated with acid and agitated for efficiency.
Goal is to oxidize the original metal form to a water soluble form.
The Purpose
In Bioleaching: Grow bacteria, Paenibacillus
Polymyxa, to extract a variety of metals from Olivine ore.
Comparative experiment – leached metals using bioleaching will be compared to acid leach.
The Purpose
In Acid-leaching: Usage of Lactic and Hydrochloric
acid to extract a variety of metals from olivine ore.
Comparative experiment of Acid-leaching of Olivine ore from various locations: Spain, Italy and Norway
The Purpose
Bioleaching and Acid-leaching: Metals extracted will be analyzed for
mass amounts using ICP-OES analysis.
Experiment Overview
Mature bacteria colonies were introduced to liquid broth sample along with pulverized ore.
Experiment Overview
Acid leaching was also done on the ore for comparison of results.
Both Lactic Acid and Hydrochloric Acid were used in leaching process.
Left for 1 week on shaker table and later centrifuged.
Experiment Overview
5 standards were made for calibration of the instrument.
24 samples were made up for acid leaching.
3 unknown replicates were made from bioleaching process.
Problems 1 : Fungi Aspergillus Niger
Originally, fungi, Aspergillus Niger was proposed
Aspergillus Niger: Important organism in biotechnology
Used in enzyme production A promising Nickel leaching micro-
organism
Problems: Fungi Aspergillus Niger
Problem? A. Niger contains toxic spores than can
be airborne
Can make people with weak immune systems become very sick may even result in death
Can cause a lung disease called Aspergillosis
Problems: Fungi Aspergillus Niger
Solution? Bacteria, Paenibacillus Polymyxa was
used
Seemed safer alternative.
Soil bacteria
Contributes in nitrogen fixation
Problem 2 : Contamination
Contamination of agar plate While incubating agar
plates it was discovered that different colonies of micro-organisms where growing along
Problem: Contamination
Solution? New agar solution was prepared Autoclaved equipment Use of biosafety cabinet Used UV light to disinfect surface
Methods to Check for viability
Bacteria when received were freeze dry
Growth and viability of bacteria was important
Temperature control and PH testing were done
What’s Next
Experimental Results
Waste/Disposal
Equipment Used (Shaker Table, Incubator, Bio-Safety Cabinet
etc.)
Case Study on Bioleaching – Current Research Projects.
Paenibacillus Polymyxa Overview
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