Biological methods for metal extraction
Higher tier only
- Extraction of metal ores from the ground is only economically viable when the ore contains sufficiently high proportions of the useful metal, such as iron ores and aluminium ores
- For low-grade ores (ores with lower quantities of metals) other techniques are being developed to meet global demand
- This is happening in particular with nickel and copper as their ores are becoming more and more scarce
- Phytoextraction and bioleaching (bacterial) are two relatively new methods of extracting metals that rely on biological processes
- Both of these methods avoid the significant environmental damage caused by the more traditional methods of mining
- Traditional mining involves a great deal of digging, moving and disposing of large amounts of rock
- Biological methods are, however, very slow and also require either displacement or electrolysis to purify the extracted metal
- Both techniques are also used to extract metals from mining wastes, which may contain small quantities of metals or toxic metals that need to be removed from that environment