The Future of Scandium Recovery from Wastes

Abstract

With growing demand for renewable and clean energy technologies, the need in rare earth metals is increasing. Scandium, which is often considered a rare earth element (REE), is a critical metal mainly used in solid oxide fuel cells (SOFCs) and high strength aluminum alloys used in aerospace and 3D printing applications. Furthermore, scandium supply is limited due to its scarcity and the high cost of its production in Asia and Russia while Europe has no production of scandium. Therefore, scandium extraction from alternative resources such as secondary resources located in Europe is of great concern. Within this context, this work provides a condensed state-of-art review of the issue of scandium recovery from industrial wastes. Priority was given to addressing the technological and economic challenges associated with the recovery of scandium from the said residues, with particular emphasis on the bauxite residue from alumina production, which represents nearly 5 million tons on dry basis per year in Europe.

Mobilizing materials to enable a fast energy transition: a conceptual framework

“…A stock is only accessible, if suitable extraction technologies exist and when it is not vital to maintain Earth system functions. For example, technologies to extract scandium from wastes are still under development (Chernoburova and Chagnes, 2021;Shoppert et al, 2022), leaving it inaccessible for the moment. Or, current biomass stocks in natural ecosystems will have to be maintained or even increased for stabilizing vital ecosystem functions (IPBES, 2019;Steffen et al, 2015) and are thus accessible only to the extent of what can grow beyond ecosystem needs.…”

Scandium Recovery Methods from Mining, Metallurgical Extractive Industries, and Industrial Wastes

“…As a result, the extraction of scandium from other resources, such as secondary resources in Europe, is a significant cause of concern. Among the most crucial scandium recovery challenges, the co-dissolution and co-extraction of metal impurities such as iron, titanium, zirconium, uranium, thorium and rare earth, which interfere with the scandium extraction [ 10 , 45 ], are mentioned. Due to the presence of several alkaline materials, the hydrometallurgical operations are typically characterized by significant acid consumption since the pH of the residue is exceptionally high [ 164 ].…”

“…The purification took place by solvent extraction (SX), ion exchange (IX), liquid membranes, adsorption, precipitation, and co-precipitation [ 42 , 43 ]. Because of its high extraction capacity, high selectivity, effective separation, high enrichment, and ability to operate on a large scale, solvent extraction is one of the most effective methods for the separation and purification of target metal ions from various aqueous solutions [ 44 , 45 , 46 ].…”

Ecotoxicity attenuation by acid-resistant nanofiltration in scandium recovery from TiO2 production waste

“…They also highlighted that the environmental effects of the intermediary products and residues of the developed closed-loop recovery processes are still not being considered. These intermediary products and residues are important in occupational health and safety, as well as in the case of an accidental release into the environment [ 28 , [30] , [31] , [32] ]. Therefore, the establishment of new, eco-friendly technologies combining waste valorisation with the possible reduction of the amount of stockpiled waste materials would be of outmost importance supported by sufficiently detailed ecotoxicity data.…”