DEVELOPMENT OF AN INTEGRATED MULTIDISCIPLINARY STRATEGY FOR GALLIUM, IRON AND MANGANESE RECOVERY FROM MINING RESIDUES IN A CONTEXT OF CIRCULAR ECONOMY

SCOTTI, ADALGISA; STEFANO, MILIA; GIOVANNA, CAPPAI; SILVANI, VANESA ANALIA; GUGLIETTA, DANIELA; FRANCESCA, TRAPASSO; GIROLAMO, BELARDI; ROSAMARIA, SALVATORI; EMANUELA, TEMPESTA; DANIELE, PASSERI; STEFANO, UBALDINI; GODEAS, ALICIA MARGARITA; BABAY, PAOLA; GONZALES, FLORENCIA; LEGUIZAMON, ROXANA; GÓMEZ, DARIO

Encuentro; XV Encuentro Internacional de Ciencias de la Tierra (ICES).; 2020

Mining and mineral-processing wastes have been giving a lot of concern in recent times. We have evaluated an integrated multidisciplinary strategy for mining residues characterization, as well as for the recovery of secondary (e.g., Fe, Mn) and critical (e.g., Ga) raw materials. After the in situ sampling campaigns in the Joda West iron and manganese mine (Keonjhar district, State of Odisha, India), residues have been characterized and the acquired mineralogical, chemical and spectral information have been used to create a map of mining residue deposits by means of the new multispectral satellite Sentinel-2A classification. Furthermore, mycorrhizal-assisted phytoextraction of metals from previously classified soils, based on sunflowers colonized by an AM fungal strain GA5 Rhizophagus intraradices, was carried out in the perspective of subsequent recovery of Ga, Fe and Mn from biomass using hydrometallurgycal and electrochemical techniques. The bioconcentration factors (calculated as the ratio between the concentration of metals in the plant tissue and in the soil) in aerial and radicular parts (BCS and BCR, respectively), and translocation factors (TF, calculated as the ratio between the concentration of metals in the aerial part and in the roots) followed the order Ga>Mn>Fe for BCS and TF, while for BCR was Ga>Fe>Mn. Bioextracting potential by phyto-mycoremediation into a Vegetable Depuration Module (VDM) was analized, getting the highest extraction for Fe (60 g/VDM), followed by Mn (38 g/VDM) and Ga (1.02 g/VDM), thus confirming a good potential for their subsequent recovery by hydrometallurgical techniques with final purification by selective electrodeposition. Results are encouraging and the application of such multidisciplinary approach can be important to develop a circular model for sustainable exploitation of mining residues.