Bio-Reclamation of Strategic and Energy Critical Metals from Secondary Resources

Abstract

Abstract:Metals with an average crustal abundance of <0.01 ppm, which are high in supply shortage due to soaring demand, can, under the excessive environmental risk and <1% recycling rate of their production, be termed as 'critical' in a limited geo-boundary. A global trend to the green energy and low carbon technologies with geopolitical scenario is challenging for the sustainable reclamation of these metals from secondary resources. Among the available processes, bio-reclamation can be a sustainable technique for extracting and concentrating these metals. Therefore, in the present paper, the potential reclamation of critical metals (including rare earth elements, precious metals, and a common nuclear fuel element, uranium) via their interaction with microbe/s has been reviewed.

Valuable Metal Recycling

“…The following papers focused on the improvement of valuable metal recycling processes through enhanced process efficiency. Ilyas et al [4] summarized methods of bio-recovery from secondary resources for strategic and energy critical metals, such as rare earth elements, precious metals, and a common nuclear fuel element; they also suggested that sustainable recycling could be achieved by means of bio-metallurgy. Reyes-Valderrama et al [5] performed a voltammetry study for the recovery of Cu, Zn, and Ni from an e-waste leach solution to understand the behaviors of leaching and electrodeposition; they also reported selective electro-deposition with different pHs.…”

Integration of microbial and chemical processing for a sustainable metallurgy

“…The mechanism of thiosulfate and polysulfides taking place in the extraction of metal values from their sulfides is presented in Fig. . Heterotrophic biological agents (bacteria or, fungi) are able to produce organic metabolic end products that can solubilize metals from carbonates, phosphate, silicates or flouride containing minerals by chelation, oxidation–reduction and acid dissolution.…”

“…Depletion of primary reserves of metals has shown unprecedented growth in the recycling of metals from divergent secondary/spent/waste materials, which have also been explored with the aid of bio‐chemical processing in recent years . Useful research carried out in this direction is summarized in Table .…”

“…4. 15 Heterotrophic biological agents (bacteria or, fungi) are able to produce organic metabolic end products that can solubilize metals from carbonates, phosphate, silicates or flouride containing minerals by chelation, oxidation-reduction and acid dissolution. Similarly some species of Pseudomonas and Chromobacterium can produce biogenic cyanide that can complex with gold and platinum group metals for their extraction.…”

“…Depletion of primary reserves of metals has shown unprecedented growth in the recycling of metals from divergent wileyonlinelibrary.com/jctb 79 secondary/spent/waste materials, which have also been explored with the aid of bio-chemical processing in recent years. 15 Useful research carried out in this direction is summarized in Table 2. 46,47, Some of the important contributions with possible potential to achieve sustainability are discussed in this section.…”