Abstract

MINING OF HEAVY METALS FROM LOW GRADE ORE USING IN SITU TECHNIQUES: BIOLEACHING AND PHYTOMINING

J. Jayabarath*, R. Sathish Kumar, P. Karthi Pandi and K. Aswinth Elango

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Abstract

Many different methods of extraction of metal from its ores have been processed using chemicals like cyanide, ammonia, acids and alkali with the drawback of depositing significant quantities of effluent or waste into the environment. In order to overcome these issues, two different bioorganic approaches have been applied viz. Bioleaching and Phytomining. Bioleaching is an effective simple technology for the extraction of metals from low-grade ores and mineral concentrates. This phenomenon has the potential to recover metals, detoxify industrial waste products, sewage sludge and can also use in the remediation of soil. It is a simple eco-friendly method for the extraction of minerals or heavy metals from mineral wastes and ores when compared to other conventional methods. Several minerals and heavy metals like Copper, Zinc, Gold, Mercury, Uranium, Arsenic, etc. can be mined using this approach. Another effective method for extraction of heavy metal is phytomining where extraction or mining of metals using hyperaccumulators (metal crops). Metals extracted from these high biomass crops produce sulphide-free 'bio-ore' and are safely disposable. This method could be applied in degraded or mined land which provides a good economical profit in the extraction of metals via cropping and also increases the level of the plantation. As these two methods have to get explored on a large scale, this review has been designed to describe the extraction of most important heavy metals like Copper, Nickel, Uranium and other heavy metals using bioleaching and phytomining.

Keywords: Bioleaching, Heavy metals, Hyperaccumulators, Phytomining