Research Projects

Modern life is increasingly driven by the technology and in this context the demand of Rare-earth elements (REE) is also growing exponentially. REEs are becoming economically significant due to their wide applications starting from information technology to health, aviation, vehicular transport, entertainment to clean energy and defence technologies. At present, China is dominating the REE industry with 85% of global export. In fact, our nation suffered a crisis due to an interruption in the supply chain of REEs. In order to break the monopoly of China on REE supply, more so to support the “Make in India” and “Clean and Green Energy” initiatives, it is very important for us to explore alternative sources of REEs not only to meet our own requirements but also to participate in the export economy. In addition, attempts should be taken to recover REEs in an environment-friendly manner using microbial interventions. REEs are associated with several ore/accessory minerals and their estimated average concentration in the Earth's crust is significantly higher than other commonly exploited elements. In general, REEs are extracted in different physico-chemical methods like glass slag method, acid dissolution, liquid media extraction, etc., which are not eco-friendly. Therefore, the present project proposal provides a green strategy for REE extraction by identifying the relatively ignored alternative natural sources. India has a very large area covered by lateritic soil which is not so productive for agriculture, besides other badlands. Similarly, the disposal of overburden from our coal and lignite mines is also an issue. Interestingly, these deposits have higher concentrations of REEs compared to the average upper continental crust composition and therefore can be used as a potential alternative source for REE recovery and provide a solution to utilize the so-called waste of coal/lignite mines and use our badlands too. The proposed project will deal initially with mainly two sources of REEs- (i) Laterite deposits of badland areas and (ii) Overburdened sand-shale strata in coal mine areas. As laterite deposits contain several ion-adsorping clay minerals, which absorb REEs in greater amounts. Similarly, after the extraction of the coal, the overburdened sand and shale stratum of the coal mines contain several REE-bearing heavy minerals, whereas shale contains ion-adsorping clay minerals, so REEs can be extracted by applying microbial techniques. Microbes have the ability to adhere REEs in their cell surface by means of electrostatic interactions, covalent bonding and van der Waals forces. On the other hand, due to glucose oxidation during metabolism, they secret several organic acids, which results in the chelation of cations with their carboxyl and hydroxyl groups and/or, the substitution of H+ for cations and release of the REEs. Thus the proposed project will try to give a green solution for REE extraction and establish a protocol for REE recovery.