Tailings Facility Research Articles

Production of low-sulphur tailings by hydrocycloning

Acid mine drainage (AMD) is an environmental problem in gold mines containing sulphur minerals. The potential for acid drainage in tailings facilities must be considered when studying their dry closure. Therefore, controlling the sulphur content in the final layer of tailings deposition has the potential to prevent AMD after closure. In this context, the rougher flotation tailings were hydrocycloning in a pilot plant in a gold mining company to assess the potential for generating modified tailings with low-sulphur content. A total of 10 samples were composited over one hour of pilot plant operation. The hydrocyclone overflow showed an average reduction of 36.2% in sulphur content and an average metallurgical recovery of 20.0%. The underflow had an average increase in sulphur content of 16.8% and 80.0% metallurgical recovery. These results demonstrated the possibility of generating modified tailings with reduced sulphur content through hydrocycloning.

Disaster scenes as a foundation for emergency response planning

This article introduces the notion of ‘disaster scenes’. In this work, we draw on interview data collected from residents impacted by the Jagersfontein tailings disaster in South Africa in September 2022. Our methodological aim is to reconstruct the experiences of impacted people in the format of empirically derived disaster scenes. These scenes provide a credible source for modelling scenarios because they showcase the prior, immediate, response and long-term recovery phases of disaster management. Studies that provide empirical detail on the lived experience of disasters confirm the heavy burden placed on impacted people largely originating from institutional decisions. The overarching empirical narrative from this case and other cognate cases is that the absence of state institutions is a factor that likely contributes to disaster events. Our argument is that sharing information that includes models of state default can empower potentially affected groups to demand safeguards and greater transparency in relation to the operation and regulation of tailings facilities.

An application of simultaneous stochastic optimisation on an open-pit copper mining complex with supply, recovery, and market uncertainties

ABSTRACT A mining complex is an integrated value chain that consists of multiple mines, stockpiles, processors, waste dumps, and tailing facilities, and where the in-situ materials mined are transformed into products sold to customers. Simultaneous stochastic optimisation provides a strategic mine planning framework that incorporates all components of a mining complex into a single mathematical representation, capitalising on the synergies between components while considering uncertainty. An application of this optimisation framework at a coper mining complex demonstrates that the incorporation of material supply, market demand, and processing recovery uncertainties into the modelling leads to production schedules that yield a higher NPV and metal recovery.

Effectiveness of Xanthan Gum and Guar Gum in Mitigating Dust Emission from Bauxite Residue Tailings Facility

Effectiveness of Xanthan Gum and Guar Gum in Mitigating Dust Emission from Bauxite Residue Tailings Facility

Disclosure hesitancy and disaster risk: A survey of tailings professionals in the global mining industry

The global mining industry faces multiple, overlapping calls for greater levels of public disclosure about tailings facilities. Tailings professionals are pivotal to the industry’s public disclosure practice because they generate much of the information stakeholders are seeking. We surveyed 183 tailings professionals across the world to explore patterns of local-level information disclosure in mining. Most respondents had limited experience disclosing information publicly or engaging locally. Our findings raise questions about how the industry is engaging with local communities about disaster risk. Unless waste management practices evolve radically in coming decades, the predicted increase in global mining activity will coincide with an exponential increase in mine waste. Given the high-stakes nature of tailings facility failures, questions about public disclosure and disaster risk remain pressing.

Quantifying heavy metal and radionuclide contamination in fish and water proximal to a uranium tailings facility: A Linshui River basin investigation, China

BackgroundThe objective of this study is to evaluate the concentrations of heavy metals and radionuclides in water and fish samples collected from six designated sampling stations along the Linshui River, in close proximity to a Uranium Tailing Pond situated in China. Additionally, it seeks to estimate the bioaccumulation of heavy metals and conduct risk assessments, both carcinogenic and non-carcinogenic, for consumers. MethodsWater and fish samples (yellowhead catfish and common carp) were systematically collected from six stations along the river from January to June 2023, adhering to ethical standards and standard protocols for assessing water quality. Samples underwent chemical preparation and analysis for heavy metals using Graphite Furnace Atomic Absorption Spectrophotometry and Cold Vapor Atomic Absorption Spectroscopy, and for radionuclides using gamma spectrometry, with all methods validated for accuracy. ResultsThe water samples showed metal and radionuclide concentrations within acceptable limits, except for higher levels of U and Th compared to background values. Heavy metal concentrations were higher in common carp compared to yellowhead catfish, with both species exhibiting a similar trend. While non-carcinogenic health risk, as indicated by target hazard quotients, was low for consumers, the health risk data emphasized the carcinogenic threats posed by U238 and Th234. ConclusionsThe study highlights the importance of implementing comprehensive river restoration measures. Additionally, the bioconcentration factor values indicate minimal accumulation of heavy metals in the muscle tissue of fish.

Geochemical and mineralogical heterogeneity of the Cantung mine tailings: implications for remediation and reprocessing

Reprocessing tailings to recover minerals of economic interest and environmental concern can add value to a project and decrease environmental risk, but dealing with heterogeneity within tailings facilities is a challenge. This study investigates the heterogeneity of the Cantung Mine tailings to assess the potential for reprocessing for both value recovery and remediation purposes. The Cantung Mine, Northwest Territories, was a world-class tungsten (W) deposit that was mined periodically from 1962 to 2015. Geochemical analysis of 196 tailings samples shows substantial heterogeneity in the elements of value (tungsten and copper (Cu)) and elements of environmental concern for acid rock drainage (iron (Fe) and sulfur (S)). Tungsten and copper concentrations range from 0.06 to 1.06 wt% W (average 0.32 wt% W) and 0.05 to 0.48 wt% Cu (average 0.23 wt% Cu). Iron and sulfur concentrations range from 8.25 to 34.08 wt% Fe (average 17.14 wt% Fe) and 2.20 to 19.70 wt% S (average 6.7 wt% S). Characterization of 29 samples by scanning electron microscope with automated mineralogy software shows that geochemical heterogeneity corresponds to mineralogical heterogeneity with variability in the concentrations of scheelite (CaWO4), chalcopyrite (CuFeS2) and pyrrhotite (Fe(1-x)S). Liberation analyses indicate that additional grinding would be necessary to recover scheelite, chalcopyrite or pyrrhotite. Pyrrhotite with monoclinic and hexagonal-orthorhombic forms were identified. Overall, the Cantung tailings display considerable heterogeneity, which could lead to difficulties in reprocessing for economic or environmental benefit, but characterizing the heterogeneity allows for systems to be optimized.

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.

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.

Measuring the In Situ Density and Moisture Content of Filtered Tailings Using an Electrical Density Gauge

Due to the logistical challenges associated with using nuclear densitometers at remote sites, the industry is seeking an alternative method to determine the in situ density and moisture content during the construction of filtered tailings facilities. This study aims to investigate the impact of salinity on soil electrical properties and evaluate the feasibility of using an electrical density gauge (EDG) to measure the in situ density and moisture content of saline filtered tailings. The results indicate a dependence of electrical measurements on salinity. To develop procedures for soil calibration models of filtered tailings, standard Proctor tests were first conducted using Devon silt. These procedures were then applied to the filtered tailings to establish correlations between electrical properties (dielectric constant, impedance, capacitance-to-resistance ratio) and physical properties (density and moisture content) at varying salinities. It is suggested to build the soil calibration model using an EDG within a water content range of 10% to 18%. Furthermore, the effectiveness of the developed calibration models has been validated, demonstrating the applicability of the EDG instrument for filtered tailings in a saline environment. However, applying the salinity correction is crucial when the sample has a considerably different salinity than the calibration model.

Triaxial testing response of compacted iron ore tailings considering a broad spectrum of confining pressures

The filtered tailings disposal (dry stacking) up to 300 m high is an alternative to overcome the drawbacks related to the slurry tailings storage in large impoundments as it is safer and demands smaller portions of the existing landform. Even so, the understanding of the denser and dewatered material response over a broad range of confining pressures is essential to safely design tall dry stacking tailings facilities. Accordingly, the present research assesses the mechanical behavior of compacted iron ore tailings through triaxial tests. A series of compression and extension drained and undrained triaxial tests were conducted over a wide spectrum of confinements (σ́3 ranging from 75 to 8,000 kPa) to check possible particle breakage occurrence and effects. The influence of the initial density due to compaction was, as well, evaluated since the tests were performed using specimens molded at distinct dry unit weight values. The results were analyzed in the light of the critical state soil mechanics and have indicated the existence of a curvilinear critical state line in the ν: log ṕ plane. Small particle breakage has occurred and can be associated with reduction in surface roughness, breakage of asperities, and reduction in particle angularity. Moreover, a tendency for static liquefaction was observed amongst the loosest specimens sheared under the lowest confining levels.

Approach to tailings facility liner configuration selection: A case study

What liner configuration should you use for a tailings facility? Do you need a geosynthetic liner? Should you include overdrains above your liner? This paper presents an approach to answer these questions for a case study tailings facility in a semi-arid environment. The case study project includes a performance criterion that the seepage flux be limited below the impoundment. Four liner configurations were shortlisted, and the efficacy of each arrangement compared with numerical modelling. The configurations are: (1) tailings directly over a liner, (2) tailings on an overdrain system over a liner, (3) tailings on an overdrain system over a blinding layer over a liner, and (4) sealing the foundation with tailings slimes (i.e., no geosynthetic membrane). This paper also presents estimates of the longevity of an HDPE liner system, as this is vital in assessing performance over very long time periods. Seepage and consolidation modelling results indicate that overdrains do not improve the potential to meet the performance criterion and overdrains have a limited post-closure consolidation benefit. All configurations with geosynthetics indicated the liner system would function adequately during the period prior to geosynthetic membrane degradation. The slimes sealing case was shown to not provide an adequate impedance to flow.

Challenges in ensuring stability whilst providing environmental compliance for existing TSFs

The stringent requirements for tailings storage facilities (TSF) following the publishing of the Global Industry Standards for Tailings Management (GISTM) have required in depth stability supported by advance testing and modelling, where in the presence of a hazardous tailings facility would require knowledge of the barrier system. Often a buttress is required to increase the factor of safety from the one originally designed, complying with stability as well as environmental requirements, and most importantly without triggering any failure during construction. The paper aim to present a project where the facility requires a buttress as the original design in the early 2000’s was not acceptable in today’s requirements. The stability pivot over a multi-layered barrier system (which does not allow Mohr-Coulomb failure criterion) and the different waste classification between the tailings and the buttress material, requiring different barrier requirements, yet to all be tailored in a constructible solution, without affecting the stability of the TSF.

Dry Stacking of Filtered Tailings for Large-Scale Production Rates over 100,000 Metric Tons per Day: Envisioning the Sustainable Future of Mine Tailings Storage Facilities

Communities and authorities have been dismayed by globally recorded tailings storage facility (TSF) failures in recent years, which have negatively affected the safety of people and the integrity of the environment. In this context, obtaining the social and environmental license to operate TSFs has become a challenging process for mining companies. This has promoted the trend of using mine tailings dewatering technologies in the mining industry, with dry stacking of filtered mine tailings being recognized worldwide as one of the most acceptable, safe, and environmentally friendly solutions. This article presents a new paradigm in managing mine tailings, with disruptive and futuristic characteristics, considering the dry stacking of filtered mine tailings for large-scale industrial production rates over 100,000 metric tons per day (mtpd). Aspects of filtered tailings management are discussed, such as (i) dewatering process plant with thickening/filtering equipment, (ii) conveyance using fixed and movable conveyor belts, (iii) construction of dry stacking of filtered mine tailings facility, and (iv) implementation of Industry 4.0 technologies for automation of the mining processes. Finally, the article discusses how the large-scale filtered mine tailings solution is applied, considering the advances in the equipment’s performance and implementation of Industry 4.0 technologies as well as the experience gained worldwide in several mining operations. The future global trend is that mining operations with high daily production of mine tailings will apply dry stacking technology without dams to guarantee sustainability, promote continuity of the mining business, ensure the safety of communities, and conserve the environment.

О возможностях использования горнопромышленных отходов в Мурманской области

Mining waste products have a significant effect on the vulnerable natural environment of the Arctic and the human health. So, the problem of mining waste utilization is of a particular relevance for the Murmansk Region. The article discusses the existing legal and regulatory framework, promising directions for the development of technologies in this area, and the current waste utilization methods. The author highlights the practical results of mining waste disposal. The tailings facilities (TSF) are considered as technogenic deposits with a low content of valuable components and so can be used in the building industry due to low cost of such materials and reduction of environmental damage during TSF removal.

Influence of Reagents on Qualitative Indicators of Artificial Anti-Deflationary Phytocenosis on Waste from a Rare Earth Tailing Facility.

This paper presents an assessment of the effect of various reagents on the qualitative indicators of anti-deflationary single-species sowing phytocenosis on enrichment waste from rare earth ores. It has been established that tailings of loparite ores are not suitable for biological reclamation due to low values of hygroscopic moisture (0.54-2.85%) and clay particles (17.6 ± 0.6%) and high content of bioavailable forms of aluminum (504 ± 14 mg/kg). Seeds of red fescue (Festuca rubra L.) were grown on the tailings of loparite ore enrichment with the addition of opoka (O), brucite (B), and vermiculite (V). The quality of the seed cenosis was assessed by the dry biomass of the above-ground parts of the plants and the plant height. A positive effect (one-way ANOVA followed by Tukey's HSD test (p < 0.05 and p < 0.01)) of the considered combinations of reagents on the growth of above-ground biomass from 31.5% (V) to 70.3 (V + O), 82.4% (V + B), and 81.8% (V + O+B) and on plant height from 53.8% (V) up to 78.6 (V + O), 83.8% (V + B), and 75.4% (V + O+B) was revealed. The use of a combination of V + O and V + B reagents made it possible to significantly reduce the content of Al (by 19.0% and 52.8%), Sr (by 16.5% and 12.9%), La (by 65.2% and 40.6%), and Ce (by 66.8% and 41.9%) in the aerial part of the sowing phytocenosis compared to control. The results obtained here can become the basis for development of a combined sorption technology for the reclamation of technogenically disturbed lands.

Water consumption assessment in mineral processing integrating weather information and geometallurgical modeling

Water is essential in mineral processing. Because water is a limited resource and many mining operations are located in water-scarce areas, proper water management is crucial. An alternative to facing water scarcity in mining is its reuse in the process. Water recirculation is limited because there are water losses associated with the plant operation and the tailings facility. Tailings composition and particle size affect the losses related to entrainment and rewetting. These parameters can be estimated by simulating the plant using geometallurgical models. Weather variables such as radiation, temperature, wind speed, and the fraction of possible sunshine, impact the evaporation expected in the tailings facility. The variability of weather conditions throughout the year implies that evaporation depends on the season. This information is used to assess the water balance in a tailings facility located in a specific region, estimating the water consumption for a given operation. Water consumption can be economically valued and included in the mine plan. This methodology is used to provide examples where a mine plan is optimized incorporating water consumption and using efficient water management criteria.

Формирование экологического ущерба при складировании сульфидсодержащих отходов обогащения полезных ископаемых

The mining industry is one of the most challenging in ensuring environmental safety. During the last century, the Karabash Copper Smelting Plant was processing sulfide ores and depositing the tailings into storage facilities that now occupy an area of more than 50 hectares. To date, abandoned tailings are a significant source of natural water, air, and soil pollution in the Karabash city district. The article comprehensively examines the environmental impact of the Karabashmed copper smelter, one of the oldest metallurgical enterprises in Russia. The effects of seepage from the two Karabashmed tailings facilities on water resources were assessed. We revealed that even outside the area of the direct impact of processing waste, the pH of natural water decreases to values 4-5. Further downstream, the infiltration water from the tailings pond No. 4 reduces the pH of river water to 3.0-3.5. The presented results of environmental engineering surveys are derived from sampling water and bottom sediments of the Ryzhiy Stream and the Sak-Elga River, sample preparation, and quantitative chemical analysis. The study revealed significant exceedances of the maximum permissible concentrations for a number of chemical elements in the impact zone of the copper ore processing tailings.

Artificial crown pillar construction and in-pit tailings disposal at the Pinos Altos Mining Complex, Mexico

ABSTRACT The Oberon de Weber open pit is part of the Pinos Altos Mining Complex owned by Agnico Eagle Mines Ltd. in Mexico. A project was initiated in 2013 to enable the deposition of tailings in this soon-to-be exhausted pit while mining the underground portion of the deposit extending below the pit. A conceptual plan was proposed for constructing the tailings facility and mining the crown pillar below it. A series of investigations, preliminary and detailed studies, and a risk assessment were conducted to prepare a plan that was technically sound, safe, and environmentally secure during operations and after closure. Several alternatives were considered and analyzed to optimize the recovery of the high-grade ore. Economic and technical analyses supported the construction of an artificial crown pillar within a narrow trench excavated at the pit bottom, combined with a 10-m rock pillar above the underground stopes. This paper describes construction of the facility, water management, and instrumentation of the crown pillar. The Oberon de Weber Tailings Storage Facility has been in operation since the end of 2015 and is performing well. The crown pillar extraction has been successful, exceeding the planned resource recovery.

Impact of Mining and Ore Processing on Soil, Drainage and Vegetation in the Zambian Copperbelt Mining Districts: A Review

The regional environmental–geochemical surveying of the long-term impacts of mining and ore processing on a large part of the Zambian Copperbelt mining district was carried out by the Czech Research Group with cooperation of the Geology Department, University of Zambia, and the Geological Survey of Zambia in the period 2002–2018. This included the characterization of various sources of contamination, the extent of contamination of soils and crops, and the degree of contamination of river water and sediments. Solid speciation studies of potentially harmful chemical elements (PHEs), plant and human bioaccessibility studies, and a range of mineralogical techniques were used to assess the pathways of PHE cycling in terrestrial and aqueous systems and their impacts on human health. Ores of the Zambian Copperbelt mining district are mined for Cu and Co, but a number of other trace elements (Pb, As, Cd, Hg, Pb, Zn) gradually accumulated in soils and stream sediments. It was concluded that the most important problems related to ore mining and processing are the contamination of soil and crops due to dust fall out from tailing facilities and emissions from smelters. Moreover, leakages of solutions from tailing dams, insufficient technological control of their stability and breakdowns on pipelines transporting slurry from treatment plants to tailing impoundments cause contamination of water courses and deposition of metal(loids) in stream sediments. However, the contamination of the Kafue River water is relatively limited due to its high neutralization capacity. In contrast, in some Kafue River tributaries, especially those close to big mining centers, the concentrations of dissolved Cu and Co are high (up to 14,752 μg/L and 1917 μg/L) and exceed Zambian effluent limits. We also recommend measures that could contribute to minimizing the impact of ore mining and processing on the environment and the health of the local population.