Bioleaching of Metal Using Acidophilic Bacteria
AIChE Spring Meeting and Global Congress on Process Safety
2012
2012 Spring Meeting & 8th Global Congress on Process Safety
General Paper Pool/Available Papers
General Paper Pool
Bioleaching of metal from spent petroleum catalyst using Acidithiobacillus thiooxidans
Bina Singh*, Ankit Lal, Banwari Lal
The Energy Resources Institute
Habitat Centre, Lodhi Road New Delhi 110003 India
Abstract
Bioleaching of metals from hazardous spent hydro-processing catalysts was attempted in the second stage after growing the bacteria with sulfur in the first stage. The first stage involved transformation of elemental sulfur particles to sulfuric acid through an oxidation process by acidophilic bacteria. In the second stage, the acidic medium was utilized for the leaching process. Nickel, vanadium and molybdenum contained within spent catalyst were leached from the solid materials to liquid medium by the action of sulfuric acid that was produced by acidophilic leaching bacteria. Experiments were conducted varying the reaction time, amount of spent catalysts, amount of elemental sulfur and temperature. At 50 g/L spent catalyst concentration and 20 g/L elemental sulfur, 94.3% Ni, after 7 days. Chemical leaching with commercial sulfuric acid of the similar amount that produced by bacteria was compared. Various leaching parameters such as contact time, pH, pulp densities, particle size, and temperature were studied in detail. Bioleach residues were characterized by SEM.
*corresponding author: Bina Singh
Environmental and Industrial biotechnology
The energy resources institute
Darbari Seth Block, Habitat Place
Lodhi Road-New Delhi-11003
Email: binasingh28@gmail.com
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