Biomining

complete info about bio mining
applications
types

1. BIOMINING Prepared by Raheela Shabbir

2. INTRODUCTION Bio mining can be defined as the extraction of minerals from ores by using microorganisms. The microorganisms actually facilitate the extraction of metals from sulfide /iron containing ores. Metals solublization process is involved in bio mining and it is a combination of microbiology and chemistry.

3. METHODS OF BIOMINING Bioleaching Bio oxidation Common metals

4. BIOLEACHING It is a classic method of bio mining .In this method low grade ore is dumped into a heap called leach pile and then soaked with weak sulfuric acid wash. Then acid react with the ores sulfide matrix and encourages the growth of bacterial strain which start to degrade ore and releases minerals /metal in fluid form

5. BIO OXIDATION It is widely used for the extraction of gold from ores this process involves exposing the ore to bacterial oxidation which degrades (breakdown) the insoluble pyrite and arsenic components as it is a precious metal only removal of interfering metal sulfides from ore. Actually bio oxidation leaves metal in solid phase and solution is discarded.

6. COMMON METALS Metals for which this technique is employed included Copper, nickel, zinc, uranium, gold and silver.

7. COMMON BACTERIAL /MICROBES: Most common microbes which are used for bio mining: Thiobacillus Leptosprillium

8. ADVANTAGES Bio mining is cheaper although it is slower it is also cleaner. Bio mining will become important in future as high grade ores are becoming exhaustible so bio mining will become the source of metal extraction from low grade ores. Metals can be extracted from polluted water also by bio mining such as waste dumps. Metals can also be recovered from industrial effluents such as sulfur reducing bacteria are used to remove dissolved metals from industrial waste. Microorganism are used to pretreat gold. Bio mining produces increased yield and less environmental impacts.

9. DISADVANTAGES Bio mining is slower than other traditional mining techniques. It is not applicable to wide variety of ores. Bio mining lacks complete control thus leading to inefficient extraction rates . Acid production is the major problem of bio mining so solid waste must be disposed of properly.