About 100kg of tailing sample containing 0.72g/t of gold was collected from the Kolar Gold Fields, Karnataka and passed the entire quantity through three processes conducted on Lab scale. The first process is Hyper accumulation of Gold from Tailing (HAGT). This process involved the aquatic plant Eichhornia crassipes commonly known as Water Hyacinth which was cultivated and harvested in ponds loaded with the 100kg of gold-bearing tailing sample. In the 2nd process, the harvested Water Hyacinth was introduced into Microbe Incubated Bio Reactor (MIBR) where in the Hydrogen, Carbon, Lignin, Hemicellulose, Cellulose and Glucose contained in Water Hyacinth were converted to natural gas by methane-producing bacteria using a proprietary process called Microbe Incubated Bio-Reaction. In the 3rd stage, which is the final stage, the gold Nuggetization process namely Microbial Enzymatic Gold Nuggetization (MEGN) was introduced to treat the product outcome from MIBR process. The MEGN process was very effective in extraction and concentration of gold. The MEGN process employed certain harmless non-pathogen microorganisms such as Cupriavidus metallidurans and Delftiaacidovorans which were cultivated by the authors in their laboratory. These microorganisms produced an enzyme called Cup A and Cop A which have the ability to convert gold compounds into their non-absorbable forms and accumulate or concentrate them in their exterior. The size of such accumulated gold compounds varied from a few microns to a few millimetres, hence are termed nuggets and the process is named nuggetization. The weight of such accumulated nuggets was a few micrograms to milligram.The net weight of the processed and dried Water Hyacinth from the first process (HAGT) was about 3.2 kg. A 100-gram sample of this was analysed for its efficacy. The concentration of metals especially gold and silver showed significant concentrations in all tissues of the plants. The analysis revealed higher contents of heavy metals such as Cadmium (Cd), Chromium (Cr) in the roots of Water Hyacinth, whereas significant concentration of Nickel (Ni), Lead (Pb), Cobalt (Co), Gold (Au), Silver (Ag), Silicon (Si) and Iron (Fe) were observed in shoots. Interestingly the content of Nickel was the highest. The gold concentration was 78mg/kg. The product of the 2nd process (MIBR) was designated as the Super-Ore which weighed about 2 to 3 % of the net weight of the pre-processed water hyacinth. The Super-Ore was subjected to Nuggetization process (MEGN) when the concentration of gold increased from 78mg/kg to 120mg/kg as analysed by fire assay, whilst the quantity of super-ore got reduced. Thus, the gold present in the 100 kg of tailing was accumulated through water hyacinth, converted to a ?super-ore? and nuggetized.
Microbial-Enzymatic Gold Nuggetization Process in Extraction of Gold from Old Mill Tailings of Kolar Gold Fields, Karnataka
₹100.00
About 100kg of tailing sample containing 0.72g/t of gold was collected from the Kolar Gold Fields, Karnataka and passed the entire quantity through three processes conducted on Lab scale. The first process is Hyper accumulation of Gold from Tailing (HAGT). This process involved the aquatic plant Eichhornia crassipes commonly known as Water Hyacinth which was cultivated and harvested in ponds loaded with the 100kg of gold-bearing tailing sample. In the 2nd process, the harvested Water Hyacinth was introduced into Microbe Incubated Bio Reactor (MIBR) where in the Hydrogen, Carbon, Lignin, Hemicellulose, Cellulose and Glucose contained in Water Hyacinth were converted to natural gas by methane-producing bacteria using a proprietary process called Microbe Incubated Bio-Reaction. In the 3rd stage, which is the final stage, the gold Nuggetization process namely Microbial Enzymatic Gold Nuggetization (MEGN) was introduced to treat the product outcome from MIBR process. The MEGN process was very effective in extraction and concentration of gold. The MEGN process employed certain harmless non-pathogen microorganisms such as Cupriavidus metallidurans and Delftiaacidovorans which were cultivated by the authors in their laboratory. These microorganisms produced an enzyme called Cup A and Cop A which have the ability to convert gold compounds into their non-absorbable forms and accumulate or concentrate them in their exterior. The size of such accumulated gold compounds varied from a few microns to a few millimetres, hence are termed nuggets and the process is named nuggetization. The weight of such accumulated nuggets was a few micrograms to milligram.The net weight of the processed and dried Water Hyacinth from the first process (HAGT) was about 3.2 kg. A 100-gram sample of this was analysed for its efficacy. The concentration of metals especially gold and silver showed significant concentrations in all tissues of the plants. The analysis revealed higher contents of heavy metals such as Cadmium (Cd), Chromium (Cr) in the roots of Water Hyacinth, whereas significant concentration of Nickel (Ni), Lead (Pb), Cobalt (Co), Gold (Au), Silver (Ag), Silicon (Si) and Iron (Fe) were observed in shoots. Interestingly the content of Nickel was the highest. The gold concentration was 78mg/kg. The product of the 2nd process (MIBR) was designated as the Super-Ore which weighed about 2 to 3 % of the net weight of the pre-processed water hyacinth. The Super-Ore was subjected to Nuggetization process (MEGN) when the concentration of gold increased from 78mg/kg to 120mg/kg as analysed by fire assay, whilst the quantity of super-ore got reduced. Thus, the gold present in the 100 kg of tailing was accumulated through water hyacinth, converted to a ?super-ore? and nuggetized.
Publication Mode |
Online |
---|---|
Publication Author |
Rajah Vijay Kumar, Vishaka V. K., Jeevitha G., Pavithra C. L. |
Publication Language |
English |
Publication Type |
Conference Paper |
Publication Year |
2021 |
You must be logged in to post a review.
Reviews
There are no reviews yet.