Review of Biohydrometallurgical Metals Extraction from Polymetallic Mineral Resources

Abstract

This review has as its underlying premise the need to become proficient in delivering a suite of element or metal products from polymetallic ores to avoid the predicted exhaustion of key metals in demand in technological societies. Many technologies, proven or still to be developed, will assist in meeting the demands of the next generation for trace and rare metals, potentially including the broader application of biohydrometallurgy for the extraction of multiple metals from low-grade and complex ores. Developed biotechnologies that could be applied are briefly reviewed and some of the difficulties to be overcome highlighted. Examples of the bioleaching of polymetallic mineral resources using different combinations of those technologies are described for polymetallic sulfide concentrates, low-grade sulfide and oxidised ores. Three areas for further research are: (i) the development of sophisticated continuous vat bioreactors with additional controls; (ii) in situ and in stope bioleaching and the need to solve problems associated with microbial activity in that scenario; and (iii) the exploitation of sulfur-oxidising microorganisms that, under specific anaerobic leaching conditions, reduce and solubilise refractory iron(III) or manganese(IV) compounds containing multiple elements. Finally, with the successful applications of stirred tank bioleaching to a polymetallic tailings dump and heap bioleaching to a polymetallic black schist ore, there is no reason why those proven technologies should not be more widely applied.

Green Processing of Strategic Elements Based on Magnetic Nanohydrometallurgy

“…It is also convenient to express equation 8 in the linearized form: (9) and the corresponding plot is shown in Figure 4 (inset).…”

“…5 Hydrometallurgy, on the other hand, is considered a relatively greener alternative. It starts from the treatment of the metal ores with acids, alkali or bacteria, 9 in order to release the metal ions. In this way, it is possible to exploit metal oxide and carbonate ores which usually exhibit a low metal content, instead of the rich sulfide ores employed in pyrometallurgy.…”

Bioleaching of Arsenic-Bearing Copper Ores

“…Finally, solvent extraction and electrowinning (SX-EW) techniques produce the formation of London Metal Exchange (LME) grade Cu cathodes from dissolved Cu [23,24]. Dump leaching can be considered as a subset of heap leaching, because this avoids sophisticated and costly ore crushing and designed heaps, since ores are staked in over 18-m piles without an advanced configuration and design [23][24][25][26]. As in heap leaching, after collecting percolated solution in the drainage system, SW-EX is applied to obtain Cu.…”

A Posteriori Analysis of Analytical Models for Heap Leaching Using Uncertainty and Global Sensitivity Analyses

“…This low cost is due to the fact that energy-intensive comminution is not required. However, this is contrasted with often slow and inefficient recovery [7,8]. In addition, small changes in metal extraction efficiency drive leaching from ilmenite (FeTiO 3 ) could be represented by four shrinking core models (spherical particles under reaction control, spherical particles under layer diffusion control, cylindrical particles under reaction control and cylindrical particles under layer diffusion control).…”