Scientific Papers, Chapters in Books and Technical Reports

LCA as a support to more sustainable tailings management: critical review, lessons learnt and potential way forward

Authors: Antoine Beylot1, Françoise Bodénan1, Anne-Gwénaëlle Guezennec1, Stéphanie Muller1

1BRGM, F-45060 Orléans, France

Keywords: LCA; tailings; waste; mineral processing; mining; metals

Abstract: This article critically reviews LCAs of tailings management, including disposal, use in construction materials and reprocessing for metal recovery. It explores 28 publications considering goal and scope definition, Life Cycle Inventory (LCI), impact assessment (IA), and interpretation. Lessons learnt are discussed: i) tailings final disposal is an environmental hotspot in the production of several metals and manufactured goods; ii) associated key impacts on human toxicity and ecotoxicity are highly sensitive to metals mobility; iii) uncertainty in LCI modelling is rarely addressed, despite expected to be high; iv) compared to classical routes, tailings use in construction materials globally enables environmental benefits, whereas environmental performance of reprocessing needs further exploration. Moreover, mineral resources accounting in LCI of tailings management is classically inconsistently combined with some depletion- or dissipation-based IA. Yet resource dissipation in LCA is promising towards supporting more resource-efficient management. Finally, this article provides suggestions towards improved LCA of tailings management: i) ensuring compliance with standards; ii) balancing metal flows in LCI modelling; iii) rethinking resources “to” and “in” tailings in LCI/LCIA modelling; iv) developing further waste and technology-specific models of emissions from tailings final disposal; v) setting coherent scenarios of future tailings management to consistently account for emissions and resources.

Scientific paper, Resources, Conservation and Recycling, 183, 106347, August 2022


Spatial component analysis to improve mineral estimation using sentinel‐2 band ratio: Application to a Greek bauxite residue

Authors: Roberto Bruno1, Sara Kasmaeeyazdi1, Francesco Tinti1, Emanuele Mandanici1, Efthymios Balomenos2

1Department of Civil, Chemical, Environmental and Materials Engineering, University of Bologna, Bologna. Italy

2Metallurgy Business Unit, MYTILINEOS S.A., Ag. Nikolaos, Viotia, 320 03, Greece

Keywords: Band ratio; Bauxite residues; Kriging of component; Mineral grade; Resources characterization

Abstract: Remote sensing can be fruitfully used in the characterization of metals within stockpiles and tailings, produced from mining activities. Satellite information, in the form of band ratio, can act as an auxiliary variable, with a certain correlation with the ground primary data. In the presence of this auxiliary variable, modeled with nested structures, the spatial components without correlation can be filtered out, so that the useful correlation with ground data grows. This paper investigates the possibility to substitute in a co‐kriging system, the whole band ratio information, with only the correlated components. The method has been applied over a bauxite residues case study and presents three estimation alternatives: ordinary kriging, co‐kriging, component co-kriging. Results have shown how using the most correlated component reduces the estimation variance and improves the estimation results. In general terms, when a good correlation with ground samples exists, co‐kriging of the satellite band‐ratio Component improves the reconstruction of mineral grade distribution, thus affecting the selectivity. On the other hand, the use of the components approach exalts the distance variability.

Scientific paper, Minerals, Volume 11(6), 549, June 2021