Bio-dissolution of metals from activated nodules of Indian Ocean

Mehta, K D and Kumar, Rakesh and Pandey, B D and Mehrotra, S P (2011) Bio-dissolution of metals from activated nodules of Indian Ocean. In: VI International Conference on Mechanochemistry and Mechanical Alloying (INCOME 2008), 1-4 December 2008, NML Jamshedpur, India.

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Abstract

The biodissolution of valuable metals from ferro-manganese nodules of Indian Ocean in presence of Aspergillus niger is a slow process. In order to improve the kinetics of bioleaching, the sea nodules were activated in high energy attrition mill thereby changing the granulometry and surface charge characteristics of the particles. The zeta potential, particle size distribution and surface area of the activated material were recorded and bioleaching was carried out by A.niger in the pH range 4.0-5.5. The mechano-chemical activation of the mixed particles (≤ 75 µm) of nodules in 10 min reduced almost 86 % material to ≤ 10 µm size with a change in zeta potential from -18 to -34 mV. Bioleaching of metals from the activated nodules was compared with that of the dissolution pattern of metals in presence of A.niger without any pretreatment as well as those under the chemical leaching conditions. The results showed the bio-recovery of more than 95% copper, nickel and cobalt each in 15 days time when the nodules activated for 10 min was leached at 5 % (w/v) pulp density, 4.5 pH and 35 ºC temperature. Bio-leaching of these metals was observed to be similar from the nodules activated for 30 min. The non-activated nodules showed ≥ 89% metal recovery in 25 days under the above conditions. The mechano-chemical activation of sea nodules has thus been found to improve the kinetics of the process and has also resulted in to the availability of wider pH in the range of 4-5 for the processing.

Item Type:Conference or Workshop Item (Paper)
Official URL/DOI:http://eprints.nmlindia.org/5128
Uncontrolled Keywords:Ferro-manganese nodules, Attrition milling, Zeta potential, Biodissolution, Aspergillus niger
Divisions:Metal Extraction and Forming
ID Code:5128
Deposited By:Mr. G Shailendra Kumar
Deposited On:11 May 2012 10:32
Last Modified:11 May 2012 10:32
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