Wind erosion and factors controlling the surface composition in abandoned tailings

Abstract

Chile has developed its mining industry for decades, mainly in the north of the country, where arid climates dominate. Many of these tailings have been abandoned to the weather. The evaluation of what happens at the surface of abandoned tailings, depending on the dominant mineralogy and climate, will be critical in assessing potential impacts from wind erosion or reworking of these deposits. Two areas of study with different climates ranging from arid to semi-arid were evaluated by mineralogy, chemistry and particle size. Using statistical analysis, it was possible to establish different types of sediments, which mainly differed in secondary mineralogy, giving rise to three clusters. When observing these clusters in the field, different surfaces can be observed, in terms of their cohesion and wind erodibility potential. The mineralogical analysis of each cluster in both climates show that although the surfaces of the deposits are similar, the particle size, amount of pyrite and other phases vary from one site to another. From the characterization of these sites, it is evident that pyrite alone will not generate acidic solutions that lead to the precipitation of secondary phases. These secondary phases will be linked to the climate (meaning available humidity), particle size and quantity of pyrite present and neutralising phases. Depending on these variables, different potentially erodible surfaces will be generated, which will lead to a greater or lesser cohesion of particles and different metal contents which is, in turn, the reason for these tailings to become a public health issue.

Sulfur Isotope Geochemistry of Ice‐Wedges in Yakutia, East Siberia

“…To date, sulfur isotope studies of natural ice samples have primarily focused on dissolved sulfate, leaving the sulfur isotopic compositions of insoluble particles essentially unexplored, but depending on the regional environmental conditions, the insoluble fraction of sulfur in the aerosol, derived from pyrite or other sulfide minerals, can be elevated up to 50%, [102]. While sulfide minerals are susceptible to oxidative chemical weathering, they can also survive to contribute to atmospheric sulfur particles, where rapid erosion and grinding processes generate large quantities of rock flour, such as in mines and quarries [20,102,103]. Glacial abrasion is one of the most effective natural means of erosion [74,104,105], and glaciers developed in the mountainous regions of eastern Siberia during the cold epochs, including the last glaciation [106][107][108].…”

MICP mediated by indigenous bacteria isolated from tailings for biocementation for reduction of wind erosion

“…The mining industry is in constant development to reduce waste generation, improve storage as well as treatment techniques for its tailings deposits. Among them, strategies related to: (i) improvement of soil mechanical properties; (ii) chemical and physical stabilization; (iii) liquefaction, permeability and neutralization of acid leachates; (iv) resistance to water lixiviation, seismic action and wind erosion; (v) bioremediation, phytoremediation and biomineralization, are some of the most studied techniques ( Edraki et al, 2014 ; De Giudici et al, 2019 ; Kiventerä et al, 2019 ; Barati et al, 2020 ; Kaseng et al, 2020 ; Kiventerä et al, 2020 ; Xie and van Zyl, 2020 ; East and Fernandez, 2021 ; Gerding et al, 2021 ; Rezasoltani, 2021 ; Woodcock, 2021 ; Zandarin, 2021 ; Jayapal et al, 2023 ; Si et al, 2023 ). Currently, biotechnological applications using biomineralizing microorganisms have generated interest in the materials industry, because they significantly reduce the energy demand to produce biocement if compared to that necessary for the conventional cement and, moreover, they can be used successfully in the neutralization of toxic elements such as PTEs or fossil fuel residues ( Akyel et al, 2022 ).…”