Tailings Management Research Articles

Optimization of Geopolymers for Sustainable Management of Mine Tailings: Impact on Mechanical, Microstructural, and Toxicological Properties

This study investigates the use of geopolymer technology as an alternative for the management of mine tailings, which is a serious environmental problem in mining areas, including the Arequipa region of Peru. In this study, the mixture of stabilized mine tailings with different percentages of binders (i.e., metakaolin and pumice) and their impact on the mechanical, microstructural, and toxicological properties of the synthesized geopolymers were analyzed. The ratios of mine tailings to binder material varied between 100/0 and 0/100. The activation was carried out with an alkaline solution of sodium hydroxide (10 M) and sodium silicate (modulus 2.5). Specimens were fabricated as 50 mm cubes, and the seven mix designs were evaluated in triplicate. The evaluations included compressive strength at 7, 14, 28, and 56 days of curing, chemical analysis by Fourier Transform Infrared Spectroscopy (FT-IR), microstructural characterization by X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM/EDS), thermal behavior by thermogravimetry and differential thermal analysis (TGA/DTA) between 40 °C and 1000 °C, and toxicological tests by the Toxicity Characteristic Leaching Procedure (TCLP, EPA 1311) to determine the efficiency of immobilization of toxic metals. The results demonstrate significant improvements in compressive strength for the F50 specimens compared to A0, with increases of approximately 300%, 270%, and 461% observed at 7, 28, and 56 days of curing, respectively, with microstructural stability with an average pore size of 7.21 μm, and efficiency in the immobilization of heavy metals in geopolymers with 30% or 40% binder (60%–70% mine tailings). The leachate concentrations of As, Cd, Pb, and Hg were below the established thresholds, indicating that the stabilized mine tailings can be classified as “non-hazardous materials”. Geopolymers with 30% to 50% binder showed strength development with microstructural stability and efficiency in the immobilization of heavy metals, complying with current regulations. Therefore, these geopolymers are suitable for various applications and in different environmental conditions.

Enhanced Tailings Dam Beach Line Indicator Observation and Stability Numerical Analysis: An Approach Integrating UAV Photogrammetry and CNNs

Tailings ponds are recognized as significant sources of potential man-made debris flow and major environmental disasters. Recent frequent tailings dam failures and growing trends in fine tailings outputs underscore the critical need for innovative monitoring and safety management techniques. Here, we propose an approach that integrates UAV photogrammetry with convolutional neural networks (CNNs) to extract beach line indicators (BLIs) and conduct enhanced dam safety evaluations. The significance of real 3D geometry construction in numerical analysis is investigated. The results demonstrate that the optimized You Only Look At CoefficienTs (YOLACT) model outperforms in recognizing the beach boundary line, achieving a mean Intersection over Union (mIoU) of 72.63% and a mean Pixel Accuracy (mPA) of 76.2%. This approach shows promise for future integration with autonomously charging UAVs, enabling comprehensive coverage and automated monitoring of BLIs. Additionally, the anti-slide and seepage stability evaluations are impacted by the geometry shape and water condition configuration. The proposed approach provides more conservative seepage calculations, suggesting that simplified 2D modeling may underestimate tailings dam stability, potentially affecting dam designs and regulatory decisions. Multiple numerical methods are suggested for cross-validation. This approach is crucial for balancing safety regulations with economic feasibility, helping to prevent excessive and unsustainable burdens on enterprises and advancing towards the goal of zero harm to people and the environment in tailings management.

Major recent failures in Brazilian mine waste containment facilities, current cases of maximum emergency level and imminent risk of rupture, and a brief sustainability analysis.

Wasteisthe materials left over after the processing of ores. Significant disasters involving waste disposal structures have occurred in Brazil in recent years and caused severe damage by contaminating soil, rivers and coastal areas, destroying native fauna and flora, interrupting the water supply and compromising its potability, putting the population's health, livelihoods and economy at risk, as well as causing 289 irreparable human deaths. Regulatory laws have become stricter, and since 2019, after the tailings dam tragedies occurred in 2015 and 2019 in Mariana and Brumadinho, in Minas Gerais, the operation of upstream-raised tailings dams has been prohibitedin Brazil. In 2022, a waste slide from a sterile pile at the Pau Branco Mine in Nova Lima promoted a dike overflow. There was the death of five people whose car was buried by a landslide on a hillside. New strategies and technologies, such as reprocessing and recycling, can be tested to ascertain whether they can help improve practices in tailings management. Indeed, mining companies' corporate responsibility and sustainability practices need to be evaluated toverify whether they better match expectations. On the other hand, more specific and detailed regulations and resolutions are required to ensure the safe monitoring and management of sterile waste piles. This paper presents a review of the facts, a discussion of the literature (mainly on recent tailings dam disasters), the current situation of mining-containingwaste structures in Brazil, a brief sustainability analysisand perspectives aimed at preventing/minimising catastrophes in the future.

Simulation-Based Integration of Thermal Drying of Fluid Fine Tailings for Tailings Management and Freshwater Conservation in Oil Sands Mining

Simulation-Based Integration of Thermal Drying of Fluid Fine Tailings for Tailings Management and Freshwater Conservation in Oil Sands Mining

Carbon footprints of tailings dams' disasters: A study in the Brumadinho region (Brazil)

Tailings dams' breaks are environmental disasters with direct and intense degradation of soil. This study analyzed the impacts of B1 tailings dam rupture occurred in the Ribeirão Ferro-Carvão watershed (Brumadinho, Brazil) in January 25, 2019. Soil organic carbon (SOC) approached environmental degradation. The analysis encompassed wetlands (high-SOC pools) located in the so-called Zones of Decreasing Destructive Capacity (DCZ5 to DCZ1) defined along the Ferro-Carvão's stream bed and banks after the disaster. Remote sensed water indices were extracted from Landsat 8 and Sentinel-2 satellite images spanning the 2017–2021 period and used to distinguish the wetlands from other land covers. The annual SOC was extracted from the MapBiomas repository inside and outside the DCZs in the same period, and assessed in the field in 2023. Before the dam collapse, the DCZs maintained stable levels of SOC, while afterwards they decreased substantially reaching minimum values in 2023. The reductions were abrupt: for example, in the DCZ3 the decrease was from 51.28 ton/ha in 2017 to 4.19 ton/ha in 2023. Besides, the SOC increased from DCZs located near to DCZs located farther from the dam site, a result attributed to differences in the percentages of clay and silt in the tailings, which also increased in the same direction. The Ferro-Carvão stream watershed as whole also experienced a slight reduction in the average SOC levels after the dam collapse, from nearly 43 ton/ha in 2017 to 38 ton/ha in 2021. This result was attributed to land use changes related with the management of tailings, namely opening of accesses to remove them from the stream valley, creation of spaces for temporary deposits, among others. Overall, the study highlighted the footprints of tailings dams' accidents on SOC, which affect not only the areas impacted with the mudflow but systemically the surrounding watersheds. This is noteworthy.

Predictive Insight into Tailings Flowability at Their Disposal Using Operating Data-Driven Artificial Neural Network (ANN) Technique

This study investigates the application of artificial neural networks (ANNs) in predicting the flowability of mining tailings based on operational variables. As the mining industry seeks to enhance operations with complex ores, the constant improvement and optimization of mineral waste management are crucial. The flowability of tailings was investigated with data driven by properties such as particle-size distribution, water content, compaction capacity, and viscoelastic characteristics that can directly affect stacking, water recovery capabilities, and stability at disposal, influencing storage capacity, operational continuity, and work safety. There was a strong correlation between water content and tailings flowability, emphasising its importance in operational transport and deposition. Three ANN models were evaluated to predict tailings flowability across three and five categories, where a model based on thickening operational variables, including yield stress and turbidity, demonstrated the highest accuracy, achieving up to 94.4% in three categories and 88.9% in five categories. Key variables such as flocculant dosage, water content, yield stress, and solid concentration were identified as crucial for prediction accuracy The findings suggest that ANN models, even with limited datasets, can provide reliable flowability predictions, supporting tailings management and operational decision-making.

Mechanism investigation of food waste compost as a source of passivation agents for inhibiting pyrite oxidation

Pyrite oxidation causes the generation of acid mine drainage (AMD), posing significant challenges in the management of sulfide tailings. Passivation agents such as humic acid have been tested to prevent pyrite oxidation. The potential of using humate rich food waste compost as a source of passivation agents to suppress pyrite oxidation was explored in this study. Batch leaching tests were conducted at room temperature, involved oxidatively leaching a pure pyrite and a pyrite-containing coal refuse sample, respectively, with and without adding the compost at acidic pH. The involved passivation mechanisms were investigated by solution leaching tests and spectroscopic (XPS) and microscopic (SEM) analysis of the pure pyrite sample and its leaching residues. Compared to the control, adding the compost led to the increases in solution pH, removal of the Fe2+/Fe3+ ions from the solutions by adsorption, and remarkable decreases (≥58 %) in sulfur concentration in both samples. Both SEM and XPS analysis indicated that a coating layer was successfully established on pyrite surface after being leached in the presence of the compost. The coating layer comprised a mixture of organic species (e.g., O-CO and N-H/C groups) and phosphate, potentially improving the likelihood of providing antioxidant protection over acidic pH. As a low-cost material, food waste compost can benefit the source control of AMD not only in terms of its surface passivation, but also its intrinsic alkalinity, metal immobilization, and low environmental risk.

Use of Submarine Tailings Disposal as Alternative Tailings Management System

The importance of the mining/milling industry in increasing the growth level and welfare of countries is quite high. However, at the end of mining/milling processes, huge amounts of waste (often known as tails) are inevitably produced that have no economic value and can even be considered dangerous due to some heavy metals they contain. These tails are highly problematic due to both their volume (difficult to manage environmentally) and toxicity (potential to cause acid/leach waters) and need to be handled outside of existing disposal methods. This article presents the effective and sustainable handling and application of tails resulting from the enrichment of copper–zinc ores, which are actively engaged in metallic mining activities in the northeast of Türkiye, with the submarine tails disposal (STD) method. In the mining operation under study, some (~55–60 wt.%) of the tails are employed as underground fill, even though the residual part is disposed of by the STD method. The characterization of ore beneficiation tails, their transportation to the subsea via a pipeline system, and discharge monitoring results are detailed in the present investigation. According to the limitations which are indicated by the Turkish Control of Water Contamination regulation, the concentration of Pb-Cu found in the results was under the allowable limit of 0.05 mg/L. The allowed 2 mg/L limit for Zn was not surpassed mainly by the concentration found in the collected samples. pH values were almost above the allowable limit of pH > 5. The results reveal that the STD technique works quite well as an integrated mine tails method in the mine under study.

Rheological Properties of a Tailing Thickened in an Excavated Ground Channel

Objectives: The recent tailings dam disasters emphasize the need to adopt best management practices focusing on the stability of these structures. This study aims to present the use of a thickening channel as an alternative for ultrafine tailings dewatering in a small iron ore mine in the Quadrilátero Ferrífero. Theoretical Framework: The research is based on the study of rheology, focusing on viscosity and yield stress as key parameters to characterize the behavior of thickened slurry. Method: The study involved the production of thickened slurry in a channel, followed by rheological characterization through sampling at different points in the thickening process. Results and Discussion: The findings indicate that the thickened slurry behaves as a non-Newtonian fluid, with all samples analyzed showing pseudoplastic behavior. There was an increase in viscosity and yield stress with increasing solids content. The deposition of thickened slurry resulted in a 36.9% increase in the volume of the studied reservoirs. Research Implications: This approach offers advantages such as low capital cost, increased water reuse, and improved geotechnical stability of deposition sites, contributing to safer and more sustainable tailings management practices. Originality/Value: The study provides a practical alternative for tailings dewatering, enhancing the safety and sustainability of tailings disposal practices in small iron ore mines.

A near-infrared spectroscopy dataset of coal and coal-measure rock under diverse conditions

The identification technology for coal and coal-measure rock is required across multiple stages of coal exploration, mining, separation, and tailings management. However, the construction of identification models necessitates substantial data support. To this end, we have established a near-infrared spectral dataset for coal and coal-measure rock, which includes the reflectance spectra of 24 different types of coal and coal-measure rock. For each type of sample, 11 sub-samples of different granularities were created, and reflectance spectra were collected from sub-samples at five different detection azimuths, 18 different detection zeniths, and under eight different light source zenith conditions. The quality and usability of the dataset were verified using quantitative regression and classification machine learning algorithms. Primarily, this dataset is used to train artificial intelligence-based models for identifying coal and coal-measure rock. Still, it can also be utilized for regression studies using the industrial analysis results contained within the dataset.

Molecular and microbial insights towards anaerobic biodegradation of anionic polyacrylamide in oil sands tailings

Anionic polyacrylamide (A-PAM) is widely used as a flocculant in the management of oil sands tailings. Nevertheless, apprehensions arise regarding its potential biodegradation and environmental consequences within the context of oil sands tailings. Consequently, it is imperative to delve into the anaerobic biodegradation of A-PAM in oil sands tailings to gain a comprehensive understanding of its influence on tailings water quality. This work explored the dynamics of A-PAM biodegradation across concentrations: 50, 100, 250, 500, 1000, and 2000 mg/kg TS. The results showed a significant decrease in A-PAM concentration and molecular weight at lower concentrations (50 and 100 mg/kg TS) compared to higher ones, suggesting enhanced degradation efficiency. Likewise, the organic transformation and methane production exhibited dependency on A-PAM concentrations. The peak concentrations observed were 20.0 mg/L for volatile fatty acids (VFAs), 0.07 mg/L for acrylamide (AMD), and 8.9 mL for methane yield, with these maxima being recorded at 50 mg/kg TS. The biodegradation efficiency diminishes at higher concentrations of A-PAM, potentially due to the inhibitory effects of polyacrylic acid accumulation. A-PAM biodegradation under anaerobic condition did not contribute to acute toxicity or genotoxicity. SEM-EDS, FT-IR and XRD analyses further revealed that higher concentrations of A-PAM inhibited the biodegradation by altering floc structure and composition, thereby restricting the microbial activity. Major microorganisms, including Smithella, Candidatus_Cloacimonas, W5, XBB1006, and DMER64 were identified, highlighting A-PAM's dual role as a source of carbon and nitrogen under anaerobic conditions. The above findings from this research not only significantly advance understanding of A-PAM's environmental behavior but also contribute to the effective management practices in oil sands tailings.

Adapted Sequential Extraction Protocol to Study Mercury Speciation in Gold Mining Tailings: Implications for Environmental Contamination in the Amazon.

Artisanal small-scale gold mining (ASGM), an increasingly prevalent activity in South America, generates mercury-contaminated tailings that are often disposed of in the environment, leading to the introduction of mercury into ecosystems and the food web, where it bioaccumulates. Therefore, studying the geochemical processes involved in the desorption and dissolution of mercury in these tailings is essential for critical risk evaluations in the short and long term. For this purpose, sequential extraction procedures (SEPs) can be useful because they help to identify the phases to which Hg is associated, although they also have limitations such as a lack of selectivity and specificity. In this work, we propose a modified four-step SEP: exchangeable mercury (F1), oxidizable mercury (F2), mercury bound to Fe oxides (F3), and strongly bound mercury (F4). To test this adapted sequential extraction method, we evaluated the Hg contamination in mercury-contaminated tailings of the Amazon basin. The results revealed a total mercury concentration of 103 ± 16 mg·kg-1 in the tailings, with a significant portion in F1 (28% of the total), where Hg was bioavailable. The large Hg concentration in F3 (36%) suggested that Fe oxides likely contribute to mercury retention. Together, the SEP results emphasize the urgent need for improved surveillance of gold mining activities and responsible tailings management practices to mitigate environmental contamination and safeguard the health of the Amazon ecosystem.

A mass and energy balance for a specific refuelling of Angra 2 nuclear power plant from a life cycle perspective

This work presents a detailed analytical balance of the material and energy flows associated with the nuclear fuel dynamics of the Angra 2 nuclear power plant (Brazil). A model is proposed for tabulation of material and energy flows, applied to each life stage of the nuclear fuel cycle, from extraction of raw material and production of nuclear fuel to post-use of fuel assemblies (FAs), when these are transformed into nuclear tailings. The tabulated and systematized data refer to the plant operation over a full load period. Approximately one year is the period of the plant operation after a regular refuelling and, at this period, all the materials and energy inputs are considered in addition to the wastes generated by the nuclear fuel cycle, including the ones due to operation and maintenance of the power plant in that period. Since 1/3 of the FAs of the core are replaced by fresh FAs, this analysis considers energy and material flows related to the production of fresh FAs. Related to these processes, it is taken into account what follows: 1) Uranium mining and processing, 2) Conversion of uranium concentrate into uranium hexafluoride (UF6), 3) Uranium (UF6) enrichment, 4) reconversion of the enriched UF6 to uranium dioxide (UO2), 5) Production of nuclear fuel - from the pellets to FAs, 6) Power generation from plant operation, and 7) Generation and management of nuclear tailings arising from the regular operation of the plant in that period. The analysis of systematized data from the various stages of the cycle allows a broader analysis and the perception of critical aspects, such as the need for technological improvements, logistical advances, care for the environment and public health, increased energy efficiency, in addition to the need for materials recycling, among other possibilities.

Комплексные решения по управлению хвостовым хозяйством на Усольском калийном комбинате

Introduction. At enterprises engaged in the extraction and processing of mineral raw materials, the volume of production waste is usually much higher than the volume of a commercial product. At the same time, there is a tendency to decrease the metal content in ores while increasing the volume of waste rock extracted when accessing ores. According to various estimates, the annual volume of waste from mining enterprises is 7 billion tons per year. The proportion of waste (tailings) in some copper-containing ores can reach 98 % or higher. Gold mining enterprises process ores in which tailings amount to 99.9 % and which contain only a few grams of gold. This trend will continue, as the enterprises of the mineral processing industry have to increase the volume of processed products. Materials and methods. Tailings processing technology solutions include equipment and services that can be used in almost any tailings farm, while tailings thickening and paste thickening can be used. Just as in the case of surface tailings management solutions, the development of solutions for underground workings begins with consideration of the available storage space underground. Post and dry storage technologies combined with closed water circuits represent the best options available for saving water in processing plants. In traditional tailings systems, the source of process water is natural sources or groundwater from mine drainage. Results. The use of sludge dewatering technology has significant advantages in handling excess brines, because it allows you to separate the mother liquor, return it to the technology and thereby prevent discharge to the sludge storage. To enhance the effect of sludge dewatering, it is necessary to limit the supply of fresh water to the technological process beyond the level of irretrievable losses (for example, evaporation into the atmosphere) by using a mother liquor or recycled brine instead of water. Discussion. liquid phase entering the sludge storage, increase the efficiency of hydraulic transport, and increase the service life of tailings facilities. Scientific works confirm the possibility of using filtered sludge from potash factories as a meliorant for agriculture and restoration of forest soils after fires. When implementing integrated tailings management, it is necessary to take into account the existing conditions and limitations of the site, the requirements of the technological process of a particular enterprise. Conclusion. The article presents the results of research on the dehydration of sludge of potassium salts. It has been established that the sludge dewatering technology significantly reduces the volume of sludge entering the sludge storage, which will increase the efficiency of hydraulic transport, increase the service life of tailings facilities. Resume. The use of sludge dewatering technology can significantly improve the efficiency of the processing plant. The development of sludge dewatering technology will require a number of research projects on transportation, storage and logistics of meliorant.

Microbially formed Mn(IV) oxide as a novel adsorbent for removal of Radium

Radioactivity of Ra isotopes in natural waters is of serious concern. Control of 226Ra concentrations in tailings ponds, which store waste from U ore extraction processes, is an important issue in mill tailings management. In this study, we tested microbially formed Mn(IV) oxide as an adsorbent for removal of Ra in water treatment. Biogenic Mn(IV) oxide (BMO) was prepared using a Mn(II)-oxidizing fungus, Coprinopsis urticicola strain Mn-2. First, adsorption experiments of Sr and Ba, as surrogates for Ra, onto BMO were conducted in aqueous NaCl solution at pH 7. Distribution coefficients for Ba and Sr were estimated to be ∼106.5 and ∼104.3 mL/g, respectively. EXAFS analysis indicated that both Sr and Ba adsorbed in inner-sphere complexes on BMO, suggesting that Ra would adsorb in a similar way. From these findings, we expected that BMO would work effectively in removal of Ra from water. Then, BMO was applied to remove Ra from mine water collected from a U mill tailings pond. Just 7.6 mg of BMO removed >98% of the 226Ra from 3 L of mine water, corresponding to a distribution coefficient of 107.4 mL/g for Ra at pH ∼7. The obtained value was convincingly high for practical application of BMO in water treatment. At the same time, the high distribution coefficient indicates that Mn(IV) oxide can be an important carrier and host phase of Ra in the environment.

Heavy metals in tailings and soils in the Pb-Zn mining areas of North-west Türkiye and health risk evaluations

Improper mining waste and tailing management in Pb-Zn mining areas (Balya and Koru) in the north-west Türkiye have not been researched sufficiently. Accordingly, concentrations of heavy metal were determined in mine tailing and soils taken from Balya and Koru, and a health risk evaluation caused by heavy metals was performed. Average Cd, Cr, Cu, Mn, Ni, Pb, and Zn concentrations in mine tailings in Balya are 35.2, 17.8, 354.7, 1735, 10, 10089, 3730 mg kg-1 and these values were determined as 9.9, 8.9, 101.5, 1308, 4.5, 1871, 1375 mg kg-1 in the tailings in Koru, respectively. The concentrations of heavy metals in the soil samples taken from both Balya and Koru were determined to be lower. The evaluation of heavy metals’ health risks was performed according to both non-carcinogenic and carcinogenic effects. The primary route of heavy metals in adults and children has been determined by oral intake. For both children and adults, the order of the carcinogenic effects of heavy metals in mine tailings and soils in Balya and Koru was Cd > Pb > Ni > Cr. As the carcinogenic risk values of Cd and Pb for adults and children in mine tailing and soils in Balya were above the limit value, the children’s Cd carcinogenic risk values were found above the limit value in mine tailing and soils in Koru. The mining area in both Balya and Koru poses a risk to human health since it is close to settlements.

Multi-year in situ hydrogeochemical monitoring of hard rock lithium mine tailings in a large-scale experimental pile

Spodumene, a lithian mineral found in granitic pegmatites, is a major source of lithium. In situ, multi-year and large-scale (>10s of tons) predictive hydrogeochemical studies can be of great value for informing mine waste rock and tailings management, not least because the material is exposed to the actual climate where it is meant to be stored. However, such studies are rare given their cost and size, and previous ones have focused mainly on sulfide-bearing materials. An experimental field cell filled with spodumene beneficiation tailings was built at the Whabouchi lithium mine site in northern Québec (Canada) and monitored during four consecutive years. In parallel, column laboratory kinetic testing on the same material was conducted for water quality parameters to compare the effect of testing scales on the geochemical behavior. Geochemical results and release rates were overall similar between laboratory and field, and consistent with previously published laboratory results for materials from the same site. The leachates were neutral to slightly alkaline, with ions from feldspars (Ca > Na > K) and residual spodumene (Li) being notable solutes. Concentrations for most solutes surveyed remained higher in the field after four years than in columns at the end of the experiment. One major difference between laboratory and field was a brief (less than 2 years) increase in iron concentrations from the field cell, resulting in Fe-oxyhydroxides precipitation, that was not observed in laboratory. The source of this iron is arguably residual ferrosilicon (used for dense medium separation) and this difference is attributed to the different testing conditions and configurations in the laboratory versus in situ. Field hydrogeological results highlight strong seasonal patterns and the rapid response of this sand-like, sulfide-poor material to ambient temperature changes and wetting-drying events. The tailings both wet and drain rapidly and easily given their water retention curve and the range of matrix suctions recorded during frost-free months. Net infiltration through the tailings was estimated to represent 55% of total precipitation in summer (June–October) 2021. This study provides a comprehensive assessment of the environmental behavior of hard rock lithium mine tailings under real, sub-arctic climatic conditions and outlines similarities and differences between laboratory- and field-generated geochemical results.

MONITORING OF TECHNOLOGICAL APPROACHES TO IMPROVE THE RELIABILITY OF HYDRAULIC ENGINEERING FACILITIES

Modern industrial production is one of the main sources of environmental pollution, actively consuming natural resources. The construction industry, in turn, despite the significant impact on the envi- ronment, is not an exception to this trend. The authors analyze the theoretical aspects of research on the environmental problems of tailings management, review of regulatory and legal regulation, as well as the development of the project of accident elimination, on the example of a company "Kazzinc". In addition, the implementation of similar projects in real practice is analyzed. Thus, the scientific significance is expressed in the systematization of the study of theoretical and methodological aspects of risk management in case of accidents at tailings facilities. This is of key importance for improving environmental safety in the construction industry and effective implementation of technological solutions in this area.

Visual inspection results and evaluation of Akhtala tailing safety based on tailing management facility safety methodology

Relevance. Mining sector is one of the leading branches of the industry in Armenia. Therefore, effective government regulation of the sector based on a sound legal basis is a necessity. Accidents at tailing management facilities are posing a high risk to people and environment especially in their near vicinity and often have a transboundary impact. The tailing management facility safety methodology elaborated under the auspices of the German Environmental Agency is an efficient tool for quick assessment of the technical condition of the tailing management facilities. Aim. To present the results of application of the tailing management facility methodology in Armenia, which was applied to the operated Nahatak tailing management facility of the Akhtala Ore Dressing Combine (Lori region, Armenia). Objects. Tailing management facility methodology was applied to the operated tailing management facility Nahatak of the Akhtala Ore Dressing Combine, for which all documentation was checked. Enrichment wastes were stored at the tailing management facility during processing copper ore from the Shamlug mine and polymetals from the Akhtala mine. The main visual inspection was carried out in three parts of the tailing management facility: main dam, drainage canal and secondary dam. Special attention was drawn to main dam conditions. The video recorded by a drone was used to explore the dam bottom-line. Methods. The tailing management facility methodology includes the following elements: the method of evaluation of Tailings Hazard Index; the tailing management facility checklists including the questionnaire for visual and documentation inspection, the evaluation matrix for the tailing management facility safety level; the measures catalogue for taking actions to improve tailing management facility safety. The questions of the each tailing management facility checklist are stated in a way to encompass the minimum set of the requirements, critical for tailing management facility safety, which allows evaluating the tailing management facility conditions. Questions in all groups of the checklist are sorted by the tailing management facility lifecycle and each subsection contains relevant questions applied to a specific stage (design, construction, operation, re-cultivation, closure). Application of the tailing management facility checklist is supported by a measures catalogue with short-, medium- and long-term safety measures. Results. The tailing management facility methodology was used/tested for the operated tailing management facility in Armenia for the first time. Тhe main problems of the Nahatak tailing management facility were identified and analyzed, and appropriate recommendations were provided based on them. Based on the obtained results it can be concluded that the main problems are related to the drainage system and the management of water flows, some parts of the primary dam that require restoration, as well as the improvement of monitoring systems. At the same time the experience of application of the tailing management facility methodology in Armenia, allowed improving this methodology and making it the most effective working tool for quick and efficient visual inspection of tailing management facilities and for thorough inspection of relevant documentations. The user-friendly tailing management facility safety methodology (with questionnaires of visual and documentation checking) is an efficient tool for quick assessment of the technical condition of the tailing management facilities, as well as for training staff both in the governance bodies and in mining enterprises.

First as a tragedy, second as a norm: global standards and Brazilian policies on the safety of mine tailings

This article seeks to analyze the regulatory framework that supervises the safety of tailings dams on an international, national and state scale, with emphasis on the management of mining dams built in Minas Gerais using the upstream technique – considered the most critical for the risk of collapse. To do this, we carried out a deductive analysis based on a literature review, combined with an inductive analysis from secondary sources (news items, reports and standards). We argue that the standards which have gained the most support from the industry, by not expressly prohibiting the existence of upstream dams, present contradictions that reproduce rather than remedy the vulnerability of territories exposed to the social and environmental risks produced by mining in Brazil, and worldwide. Based on the analyses proposed herein, we aim to understand how the problem of tailings management has been addressed by institutions on both a national and international level, thus identifying the effectiveness of standards and policies related to the problem of upstream dams.