Biomining and Bioleaching

• In relation to bacterial leaching and biomining, micro-organisms are using and releasing minerals in the earth’s crust since ancient times. Mining operations have long benefited from the activities of such naturally occurring micro-organisms, especially the ability of some bacteria to leach the metals from insoluble ores.
• Bacterial leaching is being used successfully in many countries throughout the world to recover metals from a wide variety of ores. The main metals recovered are copper and uranium, cobalt, nickel, zinc, lead and gold are also obtained.
• Bioleaching has received increasing attention because the technology has the potential to ease some of the problems experienced by the mining industry. A major problem is the greater depths.
• In many instances, it may be possible to use bacteria to leach the desired mineral out of deep or low-grade deposits without removing them from the ground, thus saving the costs of bringing vast tonnage of ore and waste rock to the surface.
• Additionally many conventional procedures consume large quantities of energy.
• The bioleaching of ores and concentrates may be an energy-saving alternative. Besides, biomining technology has potential environmental benefits.
• A long-standing problem in many mining operations has been the uncontrolled release of frequently occurring metals and acids. The controlled leaching of waste rock can result both in the recovery of valuable metals from the sites and the protection of environment pollution.