Tailings Surface Research Articles

Response surface prediction model of radon exhalation rate on beach surface of uranium tailings pond based on single factor law

Response surface prediction model of radon exhalation rate on beach surface of uranium tailings pond based on single factor law

The metal release and transformation mechanisms of V–Ti magnetite tailings: Role of the alternate flooding and drying cycles and organic acids

V–Ti magnetite tailings (VTMTs) contain various heavy metals, such as Fe, Mn, V, Co, and Ni. The groundwater pollution caused by the tailing metal release has become a local environmental concern. Although studies have demonstrated the influence of alternate flooding and drying cycles (FDCs) on metal form and mobility in minerals, little was known about whether FDCs affect the metal release of VTMTs and the transformation of released metals. This study investigated the metal release kinetics of VTMTs and the metal transformation under FDCs in the absence and presence of acid rain (sulfuric and nitric acids) and bio-secreted organic acids (acetic, oxalic, and citric acids). The results showed that FDCs promoted metal release whether or not acids were present. The maximum released concentrations of V, Mn, Fe, Co, and Ni were as high as 78.63 mg L−1,1.47 mg L−1, 67.96 μg L−1, 1.34 mg L−1, and 0.80 mg L−1, respectively, under FDCs and citric acids. FDCs enhanced the tailing metal release by increasing the metal labile fraction proportion. However, the concentrations of released Fe, Mn, V, Co, and Ni all gradually decreased due to their (co-)precipitation. These precipitates conversely inhibited the subsequent mineral dissolution by covering the tailing surface. FDCs also enhanced the tailings’ porosities by 2.94%–9.94%. The mineral dissolution, expansion and shrinkage, and changes in tension destroyed the tailing microstructure during FDCs. This study demonstrated the low metal pollution risk of VTMTs under FDCs, either in acid rain or bio-secreted organic acids. However, the increase in tailing porosity should be seriously considered as it would affect the tailing pond safety.

Fractional precipitation of copiapite-halotrichite efflorescent salts on Au[sbnd]Cu mine tailings under semi-arid climates in northern Chile

The oxidation of pyrite involves a series of chemical reactions that, depending on climatic conditions, can give rise to different mineral phases and morphologies. When oxidation takes place in semi-arid climate, the development of efflorescent salts on the surface of mine tailings is characteristic. These salts are mainly composed of Fe, Al and Mg sulfates and may accumulate valuable metals liberated through the dissolution of tailing minerals.This research aims to describe the evolution of salt precipitation from the economic and environmental perspective. For this purpose, we sampled efflorescent salts formed during the summer season on the surface of a tailing impoundment located in the north of Chile. The materials underwent comprehensive characterization utilizing X-ray techniques and scanning electron microscopy.The findings reveal a fractional precipitation in the crystallized salts. In an advanced oxidation system, characterized by multiple seasons of crystallization, dissolution and oxidation, the dry season begins with the precipitation of sulfates from a highly acidic solution dominated by Fe3+. This solution results from the dissolution and oxidation of the previous season sulfates. This initial stage is characterized by the presence of jarosite and gypsum, which are subsequently replaced by ferricopiapite. Towards the progress of the dry season, copiapite becomes more magnesian and precipitates alongside coquimbite and alunogen. Finally, halotrichite and pickeringite begin to crystallize. Base metal cations such as Co, Cu, Mn, Ni and Zn are preferentially incorporated into halotrichite-pickeringite sulfates during the most advanced evaporation phase.

Laser scanner technology in the assessment of mining tailings surface changes and rehabilitation interventions after the Fundão dam rupture, Brazil

Laser scanner technology in the assessment of mining tailings surface changes and rehabilitation interventions after the Fundão dam rupture, Brazil

Microbiological and geochemical characterization of As-bearing tailings and underlying sediments

Over the past 100 years, extensive oxidation of As-bearing sulfide-rich tailings from the abandoned Long Lake Gold Mine (Canada) has resulted in the formation of acid mine drainage (pH 2.0–3.9) containing high concentrations of dissolved As (∼400 mg L−1), SO42-, Fe and other metals. Dissolved As is predominantly present as As(III), with increased As(V) near the tailings surface. Pore-gas O2 is depleted to < 1 vol% in the upper 30–80 cm of the tailings profile. The primary sulfides, pyrite and arsenopyrite, are highly oxidized in the upper portions of the tailings. Elevated proportions of sulfide-oxidizing prokaryotes are present in this zone (mean 32.3% of total reads). The tailings are underlain by sediments rich in organic C. Enrichment in δ34S-SO4 in pore-water samples in the organic C-rich zone is consistent with dissimilatory sulfate reduction. Synchrotron-based spectroscopy indicates an abundance of ferric arsenate phases near the impoundment surface and the presence of secondary arsenic sulfides in the organic-C beneath the tailings. The persistence of elevated As concentrations beneath the tailings indicates precipitation of secondary As sulfides is not sufficient to completely remove dissolved As. The oxidation of sulfides and release of As is expected to continue for decades. The findings will inform future remediation efforts and provide a foundation for the long-term monitoring of the effectiveness of the remediation program.

Degradation of bisphenol A by persulfate activation of MoS2 composite iron tailings.

In this paper, molybdenum disulfide was grown on the surface of iron-containing tailings by hydrothermal method, and a series of highly efficient activated persulfate (PMS) iron-based catalysts were successfully prepared. The results show that in the CTM 1-200/PMS system, the additional ratio of tailings and the hydrothermal temperature have important effects on the catalyst. The catalyst prepared under the conditions of CT:MoS2 (molar ratio 1:1) and hydrothermal temperature of 200 °C (CTM 1-200) had the best degradation effect on BPA, and the degradation effect was increased by four times. The reason for the improvement of degradation efficiency is that the introduction of MoS2 accelerates the REDOX cycle between Fe(II)/Fe(III), and the reduction of Fe(III) is mainly related to Mo(IV), while the reduction capacity of S is relatively weak. Molybdenum disulfide/iron tailing composite material provides a way for tailings to solve the problem of water pollution.

A Mathematical Model for Assessing the Impact of a Man-Made System on an Air Basin

The results of many years of research on the assessment of the impact on the air basin of the technogenic system – tailings dumps of highly toxic waste using methods of mathematical statistics is presented. The research was carried out within the boundaries of the Dalnegorsky Ore District of the Primorsky Territory of the Far Eastern Federal District (Far Eastern Federal District). It has been established that the main pollutant is dust containing elevated concentrations of heavy metal compounds, which is removed from the surface of tailings dumps by air flows. The spatial and temporal patterns of the distribution of the pollutants in the atmospheric air are revealed. It has been experimentally proved that contamination of the air basin with heavy metal compounds, sulfate ion aerosols, and dust is extremely high. The ways of reducing its negative impact on the air basin are proposed.

Predicting beach profiles for thickened tailings surface deposition

Thickened tailings deposition technology can form a stack with a certain slope by depositing high-concentration tailings slurries to reduce the footprint of tailings storage facilities and water consumption. Thickened tailings slurries exhibit complex non-Newtonian behaviors. Predicting the beach profile evolution of thickened tailings is important for the tailings storage facility design and management. A novel governing differential equation (GDE) derived from the lubrication theory is proposed in this work to capture laws of beach profile formation. Experimental data from three-dimensional laboratory-scale flume tests are analyzed using the proposed GDE. The GDE avoids the discrepancy from an inappropriate coordinate system, which exists in some state-of-the-art models and exhibits higher accuracy when predicting the beach shape near the toe of a preexisted layer. Compared with the Herschel–Bulkley (H–B) model, the Zhang’s equilibrium rheological model is preferred to determine the static yield stress, which leads to the accurate estimation of the stack profile in single- and multilayer thickened tailings depositions. The in-situ beach profile of thickened tailings is predicted using a numerical technique. A case study is included to demonstrate that the prediction based on the proposed GDE is consistent with the field measurement. The beach profile prediction of thickened tailings considering thixotropy is also discussed in this study. Results indicated that the decrease of yield stress along the flow path due to thixotropy leads to the concave beach shape of thickened tailings.

Plant ash prevents acid mine drainage from sulfur-bearing tailings through multiple actions — A low-cost alkaline material

Plant ash, an inexpensive alkaline material containing organic nutrients, can provide electron donors for microbial reactions and neutralize water acidity, making it an excellent candidate for use in preventing acid mine drainage production from tailings. However, the efficacy of using plant ash alone to treat tailings and the role of microorganisms remain unclear. Therefore, the effectiveness of plant ash in acid neutralization, inhibiting oxidation of sulfur-bearing minerals, and reducing acid mine drainage production is compared to that of three other alkaline materials—volcanic ash, limestone, and fly ash—in this study. Their potential microbial mechanisms are also explored. The 63-day experimental results showed that all four alkaline materials effectively neutralized the acidity of the sulfur-bearing tailings and dramatically decreased heavy metal leaching (Fe, Mn, Zn, Pb, As, and Cd). Plant ash had a higher removal efficiency of Fe (99.9%), Mn (94.0%), and Zn (99.7%) than the other three materials, which was related to its ability to provide better precipitation and adsorption conditions. XRD observed gypsum in each treatment column, the formation of a new phase of calcium carbonate was observed in the plant ash column, and SEM showed that precipitation wrapped around the surface of tailings inhibited their oxidation process. 16 S rRNA sequencing confirmed that plant ash could inhibit AMD production through microbial action. The plant ash column had higher biodiversity than the control column, and the eutrophic flora in the plant ash column could use organic matter to consume dissolved oxygen, inhibiting tailing oxidation; however, the growth of some reducing flora resulted in As reduction, causing a slight increase in As in the leachate.

Interfacial Behavior and Dechlorination Reaction of Water Droplet Impact on a Heated Extracted Titanium Tailing Surface.

The interfacial behaviors of the droplet impact on a heated extracted titanium tailing surface are studied experimentally. The effects of surface temperatures and Weber numbers on the droplet spreading characteristics are examined. The factors affecting the mass fraction and dechlorination ratio of extracted titanium tailings under the action of interfacial behavior have been researched by thermogravimetric analysis. The compositions and microstructures of extracted titanium tailings are characterized using X-ray fluorescence spectroscopy and scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS). The interfacial behaviors on the extracted titanium tailing surface are classified into four regimes, i.e., boiling-induced break-up, advancing recoiling, splash with a continuous liquid film, and splash with a broken film. The maximum spreading factors increase with the surface temperature and the Weber number. It is found that the surface temperature has a dominant influence on the spreading factors and interfacial effect, further affecting its chlorination reaction. SEM-EDS analysis revealed that the extracted titanium tailing particles are irregular shaped. There are some fine pores on the surface after the reaction. The main concentrations are Si, Al, and Ca oxides with a certain amount of C elements. The findings of this research provide a new pathway to utilize the extracted titanium tailings comprehensively.

Geochemical and mineralogical investigation of cemented crusts in the tailings cover at Long Lake Gold Mine, Sudbury, Canada

In mine tailings, precipitation of secondary minerals may cement the tailings material and form cemented crusts or hardpans. Hardpans typically form beneath the surface of reactive tailings. However, at the former Long Lake Gold Mine near Sudbury, Ontario, cemented crusts formed in a clean sand cover above the tailings. We applied mineralogical and geochemical techniques to investigate the formation of these cemented crusts. Representative samples were collected from the sand cover and vertical cores from the underlying tailings. Elevated concentrations of arsenic (As), iron (Fe), and sulfur (S) in the sand cover indicate the upward transport of sulfide-mineral oxidation products. The shallow porewater of the tailings is acidic (pH 4 – 6) and contains elevated concentrations of As (up to 346 mg/L), Fe (up to 1844 mg/L), and SO4 (up to 12,000 mg/L). Mineralogical observations indicate that primary sulfide minerals in the near-surface tailings display moderate to strong oxidation, and secondary Fe-arsenate and jarosite minerals are formed both in the near-surface tailings and the sand cover. Upward migration of sulfide-mineral oxidation products leads to the formation of cemented crusts, which with continuing erosion, represent a long-term source of pollution to the surrounding environment.

ЦЕМЕНТИРУЮЩИЙ СЛОЙ ОТВАЛОВ КОУНРАДСКОГО РУДНИКА, ПРЕПЯТСТВУЮЩИЙ ДЕФЛЯЦИИ: МИНЕРАЛЬНЫЙ СОСТАВ, ГЕОХИМИЧЕСКИЕ ОСОБЕННОСТИ

The paper is devoted to the study of composition of the surface matter of the man-made mineral formation (MMMF), namely, tailings of the Kounradsky mine (Konyrat, Karaganda region, the Republic of Kazakhstan), and the comparison of its geochemical characteristics with the composition of aerosols. The deposit is located in an arid area of steppe zone, which is characterized by wind-formed processes, therefore, an assessment of the degree of exposure of tailing substance to them is one of the important geoecological tasks. Most of the surface of the MMMF tailings of the Kounradsky mine is composed of coarse-grained material. At the sampling points the fraction content greater 1 mm amounted to 58.7–82.5%. The moisture content for the sampling period ranged from 1.9% to 4%. It is shown that the process of an oxidation leaching of sulphide-containing substance of MMMF led to the formation of acid sulphate detached waters, which dry out quickly in dry climates, that brings about the formation of sulphate efflorescences on the surface of tailings and cementing layer. It has been determined that cement is a complex and consists of newly formed kaolinite and/or illite, jarosite, gypsum and water-soluble sulphates of Fe, Ca, Al, Mg, Na and Cu. Comparison of geochemical characteristics of aerosols collected directly at tailings and at the background point with geochemical characteristics of MMMF of the Kounradsky mine shows that today tailings are not a source of air pollutants. The source of high concentrations of Pb, Cu, Zn, As, Se, Ad, Cd in aerosols recorded at one of the points is industrial enterprises of Balkhash.

Metallurgical solid waste modified thermoplastic polyurethane composites: The thermal stability and combustion properties

AbstractAs a kind of bulk industrial solid waste, the massive accumulation of iron tailings has caused serious waste of resources and environmental pollution. In this study, a silane coupling agent (KH550) was used to modify the surface of iron tailings to produce MIT, and it was compounded with ammonium polyphosphate (APP) on thermoplastic polyurethane (TPU) to prepare a series of TPU/APP/MIT composites. Thermogravimetric (TG), cone calorimetric (CCT), thermogravimetric infrared, scanning electron microscopy, and Raman techniques were also used to analyze the combustion performance, smoke toxicity, and microscopic morphology. The TG test results showed that the compounding of APP and MIT significantly improved the residual carbon value of TPU composites at 700°C. CCT test results showed that the TPU/APP/MIT composites exhibited excellent flame retardancy and smoke suppression. Compared with pure TPU, PHRR, THR, and TSR of TPU/APP15/MIT10 composite decreased by 85.56%, 87.83%, and 86.17%, respectively, the peak release rates of CO and CO2 decreased by 69.26% and 90.34%, respectively. The above studies showed that APP and MIT have excellent flame retardant and smoke suppression effect on TPU materials, providing more opportunities for the study of TPU composites and metallurgical solid waste utilization.

Controls on the mineralogical and geochemical dispersion in soil and water around a tailing storage facility in the epithermal gold–silver mine in Central Kalimantan, Indonesia

The mineralogical and geochemical parameters on soil, waste, and tailings are major components for water quality assessments because they dictate the behavior of the chemical composition and water–rock interactions. Arsenic and trace metal contamination occasionally occurs because of the oxidation of arsenic-rich minerals and hydrothermal alteration or because of anthropogenic influences, such as industrial mining activity. This study aimed to understand the characteristics of tailings, soils, surface water, and groundwater to evaluate the possible geochemical dispersion of metals employed in tailing storage facilities. A study site at the former epithermal Au–Ag mine in Central Kalimantan, Indonesia, was selected because it was suitable for investigating the geochemical behavior of trace metals in water and solid samples and their possible contribution to metal contamination in tropical regions. A detailed study of the tailings comparing mineralogical and geochemical analysis indicates that the presence of unaltered, intermediate, and oxidized zone within the tailings can be related to the sulfides alteration indices (SAI). These zones include an unoxidized zone in the submerged areas where sulfides, including pyrite with less sphalerite and galena, remain fresh. In the intermediate zone, pyrite starts to change to iron oxyhydroxide. The SAI parameters from the intermediate zone, extending 50 cm below the tailing surface, indicate that only a few grains of pyrite in this zone are weakly altered and are capped by a thin (<10 μm) iron oxyhydroxide. The oxidized zone is indicated by traces of remaining pyrite and iron oxyhydroxide as the primary mineral. Heavy metals and rare earth elements from tailings storage facilities were scavenged from the soil solutions by groundwater. The stable isotopes of oxygen, hydrogen, and dissolved rare earth elements (REEs) were used as natural tracers in systems affected by acid mine drainage. The results showed that stable isotope and rare earth elements data do not support contamination between the surface and groundwater. This study found that the oxidation of ferrous iron to ferric ion and precipitation of Fe-oxyhydroxides in soil and water has a close spatial relationship with rare earth elements, which are concentrated only in intermediate and oxide zones.

Experimental and Numerical Study on Dynamic Characteristics of Droplet Impacting on a Hot Tailings Surface

It is quite important to clearly understand the fluid dynamic process of water droplets impacting on a hot extracted titanium tailings surface for the recovery and utilization of tailings. In this research, the finite volume simulations of the droplet impingement were developed by applying the volume-of-fluid method and were validated against experimental results. Droplet-impact experiments were performed by using a high-speed camera. The effects of the Weber number, surface tension value, and contact angle on the spreading factor were quantitatively investigated, and the distributions of pressure, velocity contour, and temperature were analyzed in detail during the impact process. We found that the numerical results of the impact process and spreading factor conform to the experiments. Moreover, the surface tension, contact angle, and Weber number have important consequences for droplet dynamic characteristics. Finally, a new maximum spreading factor model that is governed by Weber numbers is proposed for the extracted titanium tailings surface based on the experimental and numerical results. These findings provide a pathway for controlling dynamic interactions of the droplets impacting on the tailings’ surfaces.

Temporal evolution of surface and sub-surface geochemistry and microbial communities of Pb-rich mine tailings during phytostabilization: A one-year pilot-scale study.

Old mine waste repositories can present health and/or environmental issues linked to their erosion, inducing dissemination of metals and metalloids in air and water that can be attenuated through phytostabilization. Here, the effect of this widespread phytomanagement option on the biogeochemistry of a Pb-rich mine waste was evaluated with a laboratory pilot-scale experiment giving access to the non-saturated and saturated zones below the rhizosphere compartment. Amendment of the tailings surface with biochar, manure and iron-oxide-rich ochre promoted growth of the seeded Agrostis capillaris plants. These events were accompanied by an increase of pH and a decrease of Pb concentration in pore water of the surface layer, and by a transient increase of Pb, Zn, and Ba concentrations in the deeper saturated levels. Macroscopic and microscopic observations (SEM) suggest that Pb was immobilized in A. capillaris rhizosphere through mechanical entrapment of tailing particles. Microbial taxonomic and metabolic diversities increased in the amended phytostabilized surface levels, with a rise of the proportion of heterotrophic micro-organisms. Below the surface, a transient modification of microbial communities was observed in the non-saturated and saturated levels, however 11 months after seeding, the prokaryotic community of the deepest saturated zone was close to that of the initial tailings. pH and water saturation seemed to be the main parameters driving prokaryotic communities' structures. Results obtained at pilot-scale will help to precisely evaluate the impacts of phytostabilization on the temporal evolution of reactions driving the fate of pollutants inside the tailings dumps.

Release of bitumen from mature fine tailings in the presence of a polymeric dispersant

AbstractThe effect of the addition of a polymeric dispersant, sodium lignosulphonate (LS), on the dispersion of mature fine tailings (MFT) was studied using zeta potential and total organic carbon measurements. Three different types of LSs were investigated to determine the importance of molecular weight and level of anionicity of LSs on the treatment of MFT. The presence of two fractions of bitumen was identified in the tested MFT sample. A small portion of bitumen was found to occur in the form of weakly held aggregates between bitumen and fine solids. This fraction was easily dispersed by small dosages of LS, resulting in bitumen liberation to the tailings surface. A much larger amount of bitumen was found to be strongly attached to the solids, and only very high dosages of LS were capable of partly liberating this fraction. The zeta potential promoted an understanding of the mechanism of adsorption of LS on the particles and liberation of bitumen from MFT. Carbon measurements facilitated determination of the adsorption density of the selected types of LS on solid particles.

Anthropogenic and Geogenic Mercury in Surface Waters in the Mature Bathurst Mining Camp, New Brunswick, Canada

Abstract Interactions between a cyanide leach used for Au extraction and cinnabar-bearing gossan tailings at the Murray Brook mine have led to the development of an Hg-enriched contaminated groundwater plume that discharges to the nearby Gossan Creek. Naturally occurring cinnabar in the area poses a challenge in distinguishing mining-related contamination from background Hg concentrations. Surface water data from throughout the Bathurst Mining Camp was used to establish interelement relationships compared to pH and the spatial distributions of Hg, SO42−, Cl, Cu, NO3−, Zn, Pb, and Ca/HCO3− values. Statistical significance of anomalous measurements was evaluated to assess geogenic versus anthropogenic contributions of mining associated elements. Watershed analysis indicated that the Murray Brook tailings facility may sit on a basinal divide with potential for tailings leachate-impacted groundwater and surface water migration toward the northeast as well as northwest toward Gossan Creek. Elevated NO3− was detected in two streams south-west of Gossan Creek alongside greater than normal Hg concentrations. Other locations in the study area away from the Murray Brook area show little geochemical evidence for impact of mining on surface waters despite Hg concentrations as high as 0.019 µg L-1. Points with geogenic Hg concentration on the order of 0.01 µg L-1 were observed throughout the study area, particularly in the Upsalquitch River tributaries south-west of Gossan Creek and in the surface waterbodies west of the Restigouche deposit, indicating weathering of cinnabar-bearing gossan.

Stabilization of heavy metals from lead-zinc ore tailings with sodium diethyl dithiocarbamate functionalized montmorillonite (DDTC-Mt): Leaching characteristics and remediating mechanism

The mining and processing of lead-zinc ores produce many lead-zinc ore tailings, which can cause harm by releasing toxic metal ions to the environment. Therefore, the leaching characteristics, acid generation capacity, and fractions of released heavy metals from two Pb-Zn tailings, one from Guangxi designated as F and another from Inner Mongolia designated as YD, have been investigated in this work. Here, sodium diethyl dithiocarbamate functionalized montmorillonite (DDTC-Mt) was synthesized to remediate both F and YD tailings. It was found that YD tailings have a stronger acid generation potential than F tailings, and both of them could be further oxidized and release acid. Moreover, YD showed a certain buffering capacity to acid rain due to its higher calcite content, while the leaching amounts of heavy metals from F was larger than YD resulting from the former’s higher weathering degree. DDTC-Mt resulted in a superior stabilization performance to Zn, Mn and Pb from both tailings with optimal stabilization ratios, which are all above 94%. The remediating effect of DDTC-Mt on F was better than that of YD, which could be ascribed to the fact that F contained lower amount of carbonate minerals because of a higher degree of weathering in the latter. The leaching amounts and stabilization ratios of the four elements increased with increasing time and dose of DDTC-Mt, however, temperature and pH showed little or no effect. Mineralogical analysis showed minerals in F and YD before and after leaching were mainly quartz, while the contents of sphalerite and pyrite in F-DDTC-Mt and YD-DDTC-Mt decreased although they were more than those in F and YD without DDTC-Mt after leaching for 72 h. DDTC-Mt could inhibit the release of heavy metals to a certain extent by covering the surface of tailings via complexation and precipitation. Furthermore, DDTC-Mt coating can prevent the oxidation of tailings.

Heavy metal wombats? Metal exposure pathways to bare-nosed wombats (Vombatus ursinus) living on remediated tin mine tailings

Rehabilitation of disused mine sites through stabilisation and botanical restoration is ecologically important, but metal transfer pathways to colonising wildlife are often less understood and have never been studied in marsupials. The rehabilitated Royal George tin mine tailings (Tasmania, Australia) and colonisation by bare-nosed wombats (Vombatus ursinus) represented an opportunity to examine potential metal transfer from mine tailings to an herbivorous marsupial. The aim of this study was to examine metal transfer pathways from the mine tailings to wombats, and to determine if wombats are at risk from metal exposure. Concentrations of metals were measured in the tailings substrate, surface water and vegetation, as well as fur samples from a resident wombat, and non-resident (control) wombats. The mineralogy of the tailings is dominated by quartz, muscovite, feldspars, topaz, kaolinite and calcite. Concentrations of several metals were high (exceeding varying health standards) in the tailings (As, Cu, Hg, Pb, Ni, Zn), water (As, Cd, Cu, Zn) and vegetation (As, Cd, Cu, Pb, Mn, Zn). Relative to non-resident wombats, elevated levels of As, Cd, Cu, Pb and Sn were measured in the fur of a resident wombat. Based on modelling of the exposure pathways, consumption of plant material is the most likely metal transfer pathway for As, Cu and Pb, although the risks from ingestion of tailings to this fossorial marsupial should not be discounted. This study is the first to investigate metal exposure pathways to marsupials using rehabilitated mine tailings. Further research is needed to accurately quantify ecological risks and toxicity for wombats and other marsupials native to mining landscapes.