1. BIOHYDROMETALLURGY of IRON ORE

2. Present methods Pulverising iron ore to fines Agglomerating them to pellets ( temp upto 1200 degrees) Reheating in blast furnaces(1500 degrees) these process are energy intensive to date there has been no practical technique for hydrometallurgical extraction of iron

3. Hydrometallurgy methods require huge amts of reagents (acids) The problems in iron extraction by this means have been:  The standard leaching method is dissolution of fully-oxidized ore by acid.  Electrolysis of Fe+3 solution to produce metallic iron is inefficient

4. HYDROMETALLURGY Hydrometallurgy is part of the field of extractive metallurgy involving the use of aqueous chemistry for the recovery of metals from ores, concentrates, and recycled or residual materials. Hydrometallurgy is typically divided into three general areas:extractive metallurgyaqueous  Leaching  Solution concentration and purification  Metal recovery

5. Leaching In general, leaching is the extraction of certain materials from a carrier into a liquid

6. Leaching (Cont.) In the leaching process, oxidation potential, temperature, and pH of the solution are important parameters, and are often manipulated to optimize dissolution of the desired metal component into the aqueous phase.pH The three basic leaching techniques are  In-situ leaching  Heap leaching  Vat leaching

7. Alternative solution (Back ground) Since iron is a necessary nutrient for most organisms, it can only be made biologically available if it is chemically reduced, and so the iron-reducing bacteria serve a critical role in the cycling of iron in the ecosystem

8. Alternative solution (Observation) Certain bacteria (for example, Geobacter metallireducens and Shewanella putrefaciens) reduces Fe+3 to Fe+2 under anaerobic conditions, as a part of their metabolism

9. BIOHYDROMETALLURGY These microorganisms actually gain energy by breaking down minerals into their constituent elements. Bioleaching by microorganisms takes place owing to destruction of a crystal lattice of minerals, composing solid. This shakes of a lattice are causes the destruction of a mineral.

10. The process

11. Merits Using microorganisms, costs are reduced Eco-friendly method Low grade dumps are effectively leached Uses organic waste (sawmill chips and dust, papermaking sludges, miscellaneous biomass, waste carbohydrates, or even sewage sludges) as a feed for bacteria

12. Thank you