The Role of Mycorrhizal-Assisted Phytomining in the Recovery of Raw Materials from Mine Wastes

In recent years, critical and secondary raw materials (CRMs and SRMs, respectively) have received great interest within the circular economy model. In this work, the mycorrhizal-assisted phytomining (MAP) system, composed of Helianthus annuus–arbuscular mycorrhizal fungus Rhizophagus intraradices–Zn-volcanic ashes, was applied in bioreactors for the recovery of CRMs (Sr, P) and SRMs (Cr, Zn, Cu, Mn, Rb, Ni) from mining wastes of the Los Cóndores mine (Argentina). Our results showed high bioaccumulation of Sr, P, Mn, and Zn in the aerial tissues, and a high root-to-shoot translocation for Mn (4.02) > Sr > P > Rb > Zn (0.84). Mycorrhization treatment increased the root-to-leaf translocation for Cr and P and prevented translocation towards flower tissues in most elements. The estimated bioextracting potential of the MAP system (290 plants) in a vegetable depuration module (VDM) ranged from 158 mg/m3 P > Zn > Mn > 15.1 mg/m3 Sr. We demonstrated a promising and cost-effective biotechnology applicable in agronomical practices, given the exclusion of toxic elements in flower parts, as well as for the recovery of CRMs and SRMs by hydrometallurgy from plant biomass.Fil: Scotti, Adalgisa. Consiglio Nazionale delle Ricerche; Italia. Comisión Nacional de Energía Atómica; ArgentinaFil: Silvani, Vanesa Analia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; ArgentinaFil: Juarez, Natalia Andrea. Comisión Nacional de Energía Atómica; ArgentinaFil: Godeas, Alicia Margarita. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; ArgentinaFil: Stefano, Ubaldini. Consiglio Nazionale delle Ricerche; Itali

Revised Pourbaix diagrams for the vanadium – water system

The forms of occurrence of vanadium metal are determined by the major chemical reactions in the aquatic environment such as hydrolysis, oxidation, reduction, and precipitation. Depending on pH, potential and total concentration of inorganic ions and organic ligands, vanadium compounds may undergo various transformations to produce a whole range of chemical forms in aqueous systems. In this paper, a novel approach has been applied for calculating potential-pH (Pourbaix) diagrams, based on the developed thermodynamic analysis of chemical equilibria in the V–H2O system. On the basis of currently revised thermodynamic data for V(III), V(IV) and V(V) hydrolysis and original thermodynamic and graphical approach used, the repartition of their soluble and insoluble chemical species has been investigated. By means of ΔG–pH diagrams, the areas of thermodynamic stability of V(IV) and V(V) hydroxides have been established for a number of analytical concentrations of vanadium in heterogeneous mixtures. The obtained results, based on the thermodynamic analysis and graphic design of calculated data, are in good agreement with available experimental data

Sustainable recovery of secondary and critical raw materials from classified mining residues using mycorrhizal-assisted phytoextraction

In this work, mycorrhizal-assisted phytoextraction (MAP, Helianthus annuus–arbuscular mycorrhizal fungus Rhizophagus intraradices–Zn-volcanic ashes) was applied for the recovery of secondary and critical raw materials (SRMs and CRMs, respectively) from Joda West (Odisha, India) mine residues, within a novel multidisciplinary management strategy. Mine residues were preliminarily characterized by using advanced analytical techniques, and subsequently mapped, classified and selected using multispectral satellite Sentinel-2A images and cluster analysis. Selected mine residues were treated by MAP at laboratory scale, and the fate of several SRMs (e.g., Zn, Cr, As, Ni, Cu, Ca, Al, K, S, Rb, Fe, Mn) and CRMs (such as Ga, Ti, P, Ba and Sr) was investigated. Bioconcentration factors in shoots (BCS) and roots (BCR) and translocation factors (TF) were: 5.34(P) > BCS > 0.00(Al); 15.0(S) > BCR > 0.038(Ba); 9.28(Rb) > TF > 0.02(Ti). Results were used to predict MAP performance at larger scale, simulating a Vegetable Depuration Module (VDM) containing mine residues (1 m3). Estimated bio-extracting potential (BP) was in the range 2417 g/m3 (K) > BP> 0.14 g/m3 (As), suggesting the eventual subsequent recovery of SRMs and CRMs by hydrometallurgical techniques, with final purification by selective electrodeposition, as a viable and cost-effective option. The results are promising for MAP application at larger scale, within a circular economy-based approach.Fil: Scotti, Adalgisa. Comisión Nacional de Energía Atómica; ArgentinaFil: Stefano, Milia. Consiglio Nazionale delle Ricerche; ItaliaFil: Silvani, Vanesa Analia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; ArgentinaFil: Giovanna, Cappai. Consiglio Nazionale delle Ricerche; ItaliaFil: Guglietta, Daniela. Consiglio Nazionale delle Ricerche; ItaliaFil: Francesca, Trapasso. Consiglio Nazionale delle Ricerche; ItaliaFil: Emanuela, Tempesta. Consiglio Nazionale delle Ricerche; ItaliaFil: Daniele, Passeri. Consiglio Nazionale delle Ricerche; ItaliaFil: Godeas, Alicia Margarita. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; ArgentinaFil: Gomez, Martin. Comisión Nacional de Energía Atómica; ArgentinaFil: Stefano, Ubaldini. Consiglio Nazionale delle Ricerche; Itali

Treatment of Secondary Raw Materials by Innovative Processes

This paper presents an overview of the various innovative methodologies used in the recovery of valuable metals and critical raw materials from secondary sources. The review also highlights the used varieties of application on large scale in real situations and hopes to provide insights into valorization of spent sources

Scale-up of Mycorrhizal-Assisted Phytoremediation system from Technology Readiness Level 6 (Relevant Environment) to 7 (Operational Environment): Cost-benefits within a Circular Economy Context

This chapter analyzes the costs-benefits of a particular phytomining methodology named mycorrhizal-assisted phytoremediation (MAP). This MAP system is responsible for phytostabilization and/or phytoextraction of secondary and critical raw materials from contaminated soil or mining wastes. To this aim, we evaluated the application of MAP in a modified constructed wetland, the vegetable depuration module (VDM), which permits the calibration of physical-chemical-biological variables in a contaminated substrate, as well as the partition of chemical elements within the liquid phase due to leaching and solid phases (biomass and soil). This successful methodology allows to scale-up from a Technology Readiness Level (TRL) 6 (demonstration in a relevant environment) toward TRL 7 (demonstration in an operational environment), which implies the transfer to the territory

Application of Innovative Processes for Gold Recovery from Romanian Mining Wastes

The application of a new hydrometallurgical process for gold extraction by thiosulphate leaching from Romanian mining wastes, coming from Balan and Deva deposits, was studied. There was obtained 85% of Au extraction after leaching; moreover, an integrated flow-sheet, including recycling of process solution and carbon, was outlined, based on results obtained at a laboratory scale, using a schematic chemical circuit of treatment. Global recovery of the process (leaching-adsorption-desorption-electrodeposition) of about 75-80% of Au was achieved. The developed integrated flow-sheet, allows to recycle the reagents during the process, with a loss of only 5-10%, in particular thiosulphate and alcohol, for each complete circuit of treatment

Toward a Multidisciplinary Strategy for the Classification and Reuse of Iron and Manganese Mining Wastes

The aim of this paper is to evaluate an integrated multidisciplinary strategy for the characterization of mining waste, their possible recycling and reuse. The use of Fe-Mn rich wastes in arsenic removal and phosphorus recovery from water and the phytoextraction potential of metals and their possible recovery from biomass are evaluated

Preliminary Assessment of Radiolysis for the Cooling Water System in the Rotating Target of {SORGENTINA}-{RF}

The SORGENTINA-RF project aims at developing a 14 MeV fusion neutron source featuring an emission rate in the order of 5-7 x 10(13) s(-1). The plant relies on a metallic water-cooled rotating target and a deuterium (50%) and tritium (50%) ion beam. Beyond the main focus of medical radioisotope production, the source may represent a multi-purpose neutron facility by implementing a series of neutron-based techniques. Among the different engineering and technological issues to be addressed, the production of incondensable gases and corrosion product into the rotating target deserves a dedicated investigation. In this study, a preliminary analysis is carried out, considering the general layout of the target and the present choice of the target material

Połączenie chemicznych i biologiczno-chemicznych metod eliminacji metali z kwaśnego drenażu kopalnianego

Each acid mine drainage has a specific composition, but always contains sulphuric acid, dissolved heavy metals, sulphates, iron precipitates and their pH can be very low. The elimination of metals form the acid mine drainage is a severe environmental problem and has been a long-standing major concern to scientists, engineers, industry and governments. Various methods are used for the metals removal from waters, but any of them have been applied under commercial-scale conditions. Mostly studied are chemical and biological-chemical methods. Main aim of the paper was to interpret the combination of chemical and biological-chemical methods for the heavy metals elimination from the synthetic solution of acid mine drainage, coming from the zinc mine located in Tùnel Kingsmill outlet of the Rio Yaulì (district of Yauli – Perù). The metals selective precipitation as hydroxides (chemical method) and sulphides (biological-chemical method) at the various values of pH acid mine drainage is the fundamental of the examined process. For the hydrogen sulphide production the sulphate-reducing bacteria of genus Desulfovibrio was used. The selective sequential precipitation process reaches the selective precipitation of chosen metals with 97–99% efficiency – Fe, As, Al and Mn in the form of metal hydroxides, Cu and Zn as metal sulphides.Każdy kwaśny drenaż kopalniany ma określony skład, ale zawsze zawiera kwas siarkowy, rozpuszczone metale ciężkie, siarczany, osady żelaza, a jego pH może być bardzo niskie. Eliminacja metali z kwaśnego drenażu kopalnianego jest poważnym problemem środowiskowym i od dawna stanowi poważny problem dla naukowców, inżynierów, przemysłu i rządów. Różne metody są stosowane do usuwania metali z wód, ale żadna z nich została zastosowana w warunkach komercyjnych. Przeważnie badane są metody chemiczne i biologiczno-chemiczne. Głównym celem pracy była interpretacja połączenia chemicznych i biologiczno-chemicznych metod eliminacji metali ciężkich z syntetycznego roztworu kwaśnego drenażu kopalnianego pochodzącego z kopalni cynku zlokalizowanej w wylocie Tùnel Kingsmill w Rio Yaulì (dzielnica Yauli – Peru). Podstawą badanego procesu jest selektywne wytrącanie metali w postaci wodorotlenków (metoda chemiczna) i siarczków (metoda biologiczno-chemiczna) przy różnych wartościach pH kwaśnego drenażu kopalnianego. Do produkcji siarkowodoru wykorzystano bakterie redukujące siarczany z rodzaju Desulfovibrio. Proces selektywnego sekwencyjnego wytrącania osiąga selektywne wytrącanie wybranych metali z wydajnością 97–99% – Fe, As, Al i Mn w postaci wodorotlenków metali, Cu i Zn jako siarczków metali

Valorization of Mining Waste by Application of Innovative Thiosulphate Leaching for Gold Recovery

The metals and industrial minerals contained in the tailings of mining and quarrying activities, can degrade natural environments as well as human health. The objective of this experimental work is the application of innovative and sustainable technologies for the treatment and exploitation of mining tailings from Romania. Within this approach, the recovery of high grade raw materials to be placed on the market is achieved and reduction of these wastes volume are achieved. The current study is focused on hydrometallurgical process for the recovery of gold. The innovative treatment chosen is the thiosulphate process that, compared with the conventional cyanide, has several advantages (e.g., it is more ecologically friendly and is not toxic to humans). The conventional cyanidation process shows operating limits in the case of auriferous refractory minerals, such as Romanian wastes, the object of the study. An important characteristic of thiosulphate leaching process it has the best selectivity towards gold; it does not attack the majority of the gangue mineral constituents. Gold extraction of 75% was obtained under ambient conditions of temperature. Moreover, the overall process achieved about 65⁻67% Au recovery, this being in line with the conventional cyanidation process. As these results are obtained by application of the thiosulfate process on a low gold content ore, they may be considered encouraging. The optimization of process parameters and operating conditions, should permit the best results in terms of process yields to be achieved