Tailing Dumps Research Articles

Совершенствование методов эколого-экономической оценки процессов добычи и переработки железной руды корпораций арктической зоны России на основе математического моделирования

Iron ore production traditionally performs an important function in providing the world's manufacturing industry with raw materials and semi-finished products, and plays an important role in the socio-economic development of the regions of the North of Russia. One of the key issues of field operation remains the current, accumulated and potential environmental damage to the territories of location associated with the accumulation of waste from primary processing of raw materials stored in tailings. The development of raw material extraction technologies makes it possible to increase the time horizon for the exploitation of deposits, but requires measures to increase the capacity of the tailings storage facility, modernization of hydraulic structures serving it. In the article, on the basis of forecast data on the development of tailings facilities of the ‘Karelsky Okatysh’ JSC for the period up to 2043, a model for calculating the occupancy of a tailings pond in the event of a new dam break is constructed. At the moment, within the framework of the development of tailings facilities at the specified enterprise, the organization of the construction of a tailings dump on the site of an alluvial beach is being carried out. One of the bases of decision-making is risk assessment, which includes an assessment of emergency situations. 2 scenarios of accidents at the GTS are considered: the loss of static stability of the dam, i.e. the break of the dam wall during normal operation (A1) and the erosion of the body of the dam as a result of the overflow of water over the crest, i.e. the overflow of water over the top of the dam with subsequent destruction of the wall (A2). The assessment of the capacity of the new and old tailings dam (settling pond) and the capacity of new and old hydraulic structures and the analysis of the possibility of using a settling pond and a system of spillway structures, depending on the degree of construction of the tailings pond. The conclusion is made about the necessary measures to improve this system for the localization of man-made accidents in various scenarios.

Restoration of Biological Potential in the Territory of the Gold-Processing Plant Tailings Storage Facility

The features of the impact on the natural environment of the gold-processing plant tailing dump are considered. The factors that slow down the natural recovery of disturbed areas have been revealed. Attention is drawn to the fact that it is necessary to carry out a biological stage of land recultivaiton with respect to the natural-geographical and socio-economic conditions of the area where the gold-processing plant is located in order to restore the productivity of disturbed lands. An algorithm of plants selection for biological recultivaiton is presented. The factors that can affect the successful reforestation of the area are specified.

Numerical modeling of atmospheric pollution in the approaches of random selection of discrete dusting sites and interval distribution of dust size

The results of numerical simulation of atmospheric pollution in Apatity are presented with variations in the dusting area of discrete spatially spaced areas selected randomly and the wind flow velocity. CFD modeling in the volumetric formulation was performed using the COMSOL program. To calculate the aerodynamic characteristics, an incompressible fluid approximation was used using the standard ( k -ε) turbulence model. The process of fine dust propagation is modeled by numerical solution of the convective-diffusion impurity transfer equation taking into account the deposition rate. Numerical experiments (with a total number of more than 1,400) were carried out with a variation of the wind flow velocity from 5 to 23 m/s and a dusting area from 2 to 10 ha with a random selection of 20 discrete sites. Dynamic velocity distributions for specific areas of dusting, interval and total spatial distributions of dust pollution (dust particles with a diameter from 0 to 70 microns in increments of 10 microns) are obtained. The peculiarities of the influence on the levels of atmospheric pollution of specific areas of Apatity depending on the location of dusty areas on the surface of the beach of the tailings dump are noted. The calculated levels of atmospheric pollution in the center of Apatity averaged by the number of combinations of dusting sites are analyzed and generalized to functional dependencies. The calculated dependences of the dust concentration on the dusting area at a fixed wind speed are described by linear functions. The dependence of the dust concentration on the wind flow velocity at a fixed dusting area can be approximated by a power function. The generalized functional dependence makes it possible to predict the dust concentration in Apatity depending on the dusting area of randomly selected discrete areas on the surface of the tailings dump and the wind flow velocity. The obtained dependence permits to make a forecast of the critical dusting area at which the level of atmospheric pollution reaches the maximum permissible concentrations, depending on the speed of the wind flow.

Concept of natural restoration process of the petrophyte ecosystem on the surface of the tailing dumps in the limestone quarry "Lafarge Ciment" (Moldova) S.A.

The process of natural restoration of the petrophyte ecosystem consists of the following stages: formation of tailing dumps, initiation and restoration of biodiversity on the surface of tailings dumps, solification (formation of new soil) on the surface of dumps, accumulation of nutrients (nitrogen, phosphorus, K2O) and humus formation in the layers of newly formed soil on the surface of tailings dumps depending on their age. The stages are established experimentally by studying the dynamics: the development of the number of plant species on the surface of the dumps, the degree of evolution of regosols in the chronological sequence, the results of increasing the nutrient content and humus formation depending on the age of the studied tailing dumps. The regularity has been demonstrated regarding the process of soil formation on the surface of tailings dumps, which represents the succession and mutual interaction of the natural processes of initiation and development of plant biological diversity on the surface of dumps, solification (new soil formation), nutrient accumulation and humus formation in soils, which take place simultaneously without human intervention and ensures the process of natural formation of the petrophyte ecosystem.

Effect of Anions and Related Organic Compounds on the Kinetics of Thiocyanate Oxidation in a Solar-induced Oxidative System

The effect of anions (hydrocarbonates, chlorides, sulfates) and organic compounds (xanthates) on the kinetics of thiocyanate oxidation in a photoinduced iron-persulfate system was studied using natural sunlight as a radiation source. It was found that the introduction of anions into the solution inhibits the degradation of thiocyanates. Hydrocarbonates have the maximum effect, so at a HCO–3 concentration of 1 mM, the processing time required for the complete destruction of thiocyanates increased from 6 to 15.7 minutes. At high concentrations of bicarbonates (≥5 mM), the oxidation efficiency of thiocyanates does not exceed 52 %. The adding of butyl xanthate into the solution has no significant effect on the photochemical oxidation of thiocyanates. In real water matrices (tap water and circulating water of the tailing dump of a gold mining plant), oxidative processes are significantly slowed down. In tap water, this effect is mainly due to the influence of hydrocarbonates, and in waste water, it is due to the multicomponent nature of the water matrix. The efficiency of wastewater treatment from thiocyanates was 100 %, for COD – 82 %, for dissolved organic carbon – 65 %. No cyanides were found after the treatment

Mercury in Soils and Air in Areas with Anthropogenic Dispersion Halos and High Natural Geochemical Background

A monitoring study of Hg distribution in soils and air (pedogenic and atmospheric) in residential settlements and surrounding areas with high natural geochemical Hg background and/or affected by man-caused impacts due to mining activities has been performed. Sites of the AltaiSayan mercury province have been studied: part of the Kurai mercury zone (Aktash settlement, Kurai campo, Chazan-Uzun settlement, Altai Republic) and part of the Ursk ore field (Ursk settlement and Ursk tailing dump, Kemerovo region). The third site is located in Kuznetsk Alatau (part of the Saralinsky gold ore cluster, settlement of Priiskovy and its tailing dump, the settlement of Ordzhonikidzevsky, Republic of Khakassia). Hg background concentrations in air and soils have been detected.

Polyvariance of ontogeny of Castilleja lapponica Gand. under industrial pollution of the Subarctic

Studies of the cenopopulations of Castilleja lapponica Gand. - the endemic Arctic, North European species were carried out in the Lovozersky Mountains (Murmansk region). Monitoring of the cenopopulations of C. lapponica continued for 2 years under chemical and radiation pollution of the environment (30-60 uR/hr) by the Lovozersky Mining and Processing Plant where the tantalum-niobium ores and rare earth raw materials are mined and processed. Wastes of ore dressing are homogeneous sands, which are stored in the Tailing Dump. The study was held at stationary test sites in the tundra meadows and in the vicinity of the Karnasurt Tailing Dump. The polyvariance of ontogeny in cenopopulations of C. lapponica under the industrial pollution and in the natural environment of the tundra has been revealed. It is shown that under the technogenic stress, Castilleja, which reproduces in tundra meadows mainly vegetatively, switches to seed reproduction. Ontogeny spectra are unstable: in the first year of monitoring, seedlings are dominating, in the second - generative plants. Radiation stimulates the germination of seeds, the intensity of sexual reproduction increases, but most of seedlings are eliminated up to the next year. The high level of dooming of generative shoots and individuals, teratogenesis of inflorescences has been identified. The vitality of individuals decreases, the density of cenopopulations changes. Seed reproduction under conditions of the environment pollution by rare elements and radionuclides can be considered as an adaptation that contributes to the survival of C. lapponica.

Сравнительная оценка потенциальной радиационной опасности хвостохранилищ Согдийской области Таджикистана

The global environmental changes have been observed since the nineties of the twentieth centu-ry. The current environmental situation is caused mainly due to the intensive human activity. Dur-ing 46 years, from 1945 to 1991, radioactive waste from uranium processing was accumulated in the Sughd region in Tajikistan, the former USSR Republic. According to various estimates the to-tal amount of accumulated radioactivity varies from 240 to 285 TBq. The tailings are the major sources of environmental pollution, they contain emanating gas, aerosols, dust and filterable solutions. The purpose of the work is to conduct comparison assessment of the potential radiation hazard of “Digmai” and “Adrasman” tailing dumps and Istiklol-city in the Sughd region and to estimate radiological risks to the population living near the tailing dumps. For radon monitoring both integral and instantaneous measurements were used. For instant measurements of radon volu-metric activity the PPA-01M-03 LLC “HTM-Protection” (Russia) raidometer was used. The back-ground radiation in the area under study was measured with Dosimeters DKS-96 “Dose” (Rus-sia), DKS-AT1123 “Atomtech” (Belarus), MKS-AT6130 “Atomtech” (Belarus) and PackEye FHT complex-1377 “Thermo” (Germany). The paper presents data on comparison assessment of po-tential hazard of radioactive tailing dumps in the Sughd area. The impact of uranium tailing dumps on radioecological situation in the Sughd region, as well as in cities and districts of the Sughd region was assessed. The most unfavorable radioecological situation in the Sughd region is in areas with the ambient dose equivalent power (MAED)>0.35-0.40 μSv/h. The coordinates of the areas location coincide with coordinates of the radioactive tailing dumps Istiklol-city and Gaziyeon (“Digmai”) location, and their adjacent territories. According to comparison assessment, the tailing dumps “Digmai” and “Factory of Poor Ores” (Istiklol-city) are potentially the most haz-ardous facilities. It means that for radioecological safety of the environment and the population, it is recommended to carry out cleaning and remediation of the tailing dumps as a priority: «Dig-mai» and «Factory of poor ores».

Auscultation of the RTH flotation tailing dump in Bor with reference to the stability of dams and dykes at the tailing dump

The RTH flotation tailing dump, located in the old open pit RTH in Bor about 500 m southeast of the Flotation Plant, has been in continuous operational work since 1985. The flotations tailing dumps are important mining facilities that are constantly changed during their exploitation period. Due to the changes occurring in the tailing dump during its exploitation, it is necessary to perform a continuous technical and technological surveillance-auscultation in order to collect parameters in real time to predict the phenomena, which will enable the normal exploitation of tailing dump. This paper presents the current state of the flotation tailing dump RTH, based on the auscultation monitoring program, carried out in the period August 2020 to February 2021. As for the normal exploitation of the flotation tailings dump in safe and stable conditions, a special attention is paid in this paper to the stability analysis of the dams I and II, as well as the sand dyke between them.

Determination of Minerals of Cassiterite Tailings and its Recycling Potential Using Empirical Method at Plateau State Nigeria

The mineral potential of cassiterite fines from tailing dumps in the Jos Tin Mining Community Resource Centre (MCRC), Plateau State Nigeria, were studied through a wet concentration process and dry electrostatic and magnetic processes and then evaluated using empirical evidence. Three samples of the tailing dumps with the size of mineral smaller than 5 mm were collected at random through the “Tin Mining Community Resource Centre”. The huge pile of the tailing dumps may have an environmental impact in the area, so they need to be treated and recovered for the valuable heavy minerals and sand tailing for the local construction industry. The grade of the average tailing dumps as analyzed using XRF were 2.08% Sn, 3.51% Nb, 25.5% Fe, 14.91%Ti, 8.36% Zr, 12.99% Al, and 45.68% Si. The percentage compositions of the cassiterite tailings were expressed to its simplest genetic mineral forms using an empirical formula. The genetic mineral forms were ilmenite, zircon and sand. Since ilmenite has the highest concentration in the cassiterite tailings and the highest economic values, then recycling of ilmenite should be ascertained. After the wet processing by the screen, hydro cyclone, spiral concentrator, and shaking table, the concentrate consists the most of, ilmenite, zircon, and sand. The following dry processes used rotary dryer, screening, electrostatic separator, magnetic separator to separate cassiterite from the heavy minerals and sand. The final iron and titanium concentrate can be upgraded to 72% Fe and Ti using certain reagents such as fluoride acids which can be sold to the Iron ore smelting plant.

Research on possibilities for monitoring stability of adjacent slopes to transport routes

Development of human society also implies modernization, respectively extension a road and railway transport structures. From this perspective, in order to achieve performance in the field of traffic safety, actions are also required to monitor the slopes, tailings dumps (active or greened) adjacent to transport routes where there are uncertainties regarding their stability. Ignoring stability and landslides can lead to loss of life, as well as significant material damage. Thus, the paper mainly addresses the issue of monitoring the slopes adjacent to road and rail transport routes where there are uncertainties regarding the control of landslides, as well as possibility of alerting before this occurs. From the multitude of possible solutions to be applied in the field, an equipment was developed and realized, which was experienced in real working conditions, and the results confirm validity of assumptions and certify the operation.

Geomechanical characteristics of smelting slag from the depot in Bor

During the geotechnical research at the RTH flotation tailing dump in Bor, the environment representing the so - called "anthropogenic layers" of smelting slag was singled out in the engineering geological materials of the field. It is a petrified, semi-metallic material, which forms layers in the field or is spread in a loose state. This paper presents the results of geomechanical and chemical tests, as well as the SEM analysis of samples of this material.

Rehabilitation of the landslide at the "Landfill 3" in the zone of the Čukaru Peki flotation tailing dump

The "Landfill 3" was formed at the location of the flotation tailing dump "Čukaru Peki", where the earthen material, created during the dam construction of the flotation tailing dump was placed. A part of the deposited material and substrate at this landfill has slipped that endangers the local road and "Kusak" stream at the landfill foot. That is why this landslide needs to be rehabilitated.

Evaluation of copper tailings from the abandoned Messina Mine for possible reuse in recreational projects, South Africa

Historic mining of copper around Musina Town left behind a sizeable unrehabilitated tailing dump. This article reports on the study conducted to investigate the suitability of using copper tailings as sand replacement in recreational projects. The methodology used involved analyzing the particle size distribution and plasticity index (PI) of the tailings and determining their particle density, bulk density, particle shape, total porosity, and permeability coefficient. The pH of the tailings, major element oxides, and heavy metals composition were all analyzed. The tailings were classified as poorly graded sand with silt (SP-SM). Low fines (9.6%) and PI (1.4) values revealed that the copper tailings were texturally suitable for application in rootzones of sports fields, courts for beach volleyball, and bunkers of the golf courses. Their particle density (2.90 g/cm³), bulk density (1.53-1.89 g/cm³), porosity (34.62-47.04%), and permeability (1.42 x 10-3 cm/sec) were all within the recommended range for application in rootzones. The angular particles of the tailings supported their uses in the bunkers. However, their pH (7.9) and high quartz content (69% SiO2) confirmed their suitability for rootzones. However, the high concentration of Cu (1872.0 mg/kg) and Cr (159.5 mg/kg) was identified as a potential risk of using the copper tailings in rootzones. This and the relatively high Al2O3 (11%) and Fe2O3 (8%) suggested that the copper tailings should be first washed or processed before being used in any recreational projects. Developing a suitable technique for processing the studied copper tailings to enhance their properties for different recreational projects was recommended.

The Current Radiation Situation of the Territory Near the Uranium Mining Enterprises of Northern Kazakhstan

Radioactive waste near the industrial zones of the mining administrations of the Stepnogorsk Mining and Chemical Combine, which occupy vast areas of the territory, remains an urgent problem for Northern Kazakhstan. For example, waste rock processing referred to as “tailings”, is contained in huge industrial basin-lakes, called tailings. Each liter of jelly-like “pulp”, in addition to carbonates of arsenic, molybdenum, phosphorus and other chemical elements, contains up to 1 g of active uranium, as well as radium and thorium. As a result of the pedestrian gamma survey, the authors identified a locally contaminated area in the northwest direction from the sanitary protection zone of the tailing dump of the Stepnogorsk Mining and Chemical Combine. It has been established that, according to the indices of radioactive contamination of water bodies, the stagnant water bodies of the Manybaiskiy and Sulukamysskiy thalweg located behind the sanitary protection zone of the tailing dump of the Stepnogorsk Mining and Chemical Combine are classified as contaminated.

Ecological and Economic Aspects of Phosphogypsum Safety Management at the Former Uranium Production Site “Pridniproivsky Chemical Plant”

Purpose: Justification the possibility of safe re-use and recycling of the residues of Uranium-containing raw material processing as an element of the remediation strategy for bringing the site of the former "Prydniprovsky Chemical Plant" (PChP)to a safe state. Methods: Site specific field studies and analytical methods for determining of the radionuclides of Uranium-Thorium series, as well as useful mineral elements in the residues of Uranium production, assessment of safe management and possible options for its re-use and recycling. Results: According to the results of monitoring studies on the radionuclide and hydrochemical composition of groundwater at the PChP industrial site for the period from 2009 to 2021 year, a high content of sulfates and an increased content of uranium in groundwater under the body of the Dniprovske tailing dump, which has a phosphogypsum coating on its surface, was revealed. Phosphogypsum is considered, on the one hand, as a source of groundwater pollution, and on the other, as a potential resource for its possible reuse and processing. The results of experimental studies of the content of natural radionuclides and the elemental composition of mineral residues of ore production at the site of the former uranium ore processing plant "PChP" are also provided, as well as an safety assessment of their handling and the options of their possible processing as an element of the strategy for bringing the site to a safe state. Conclusions: The possibility and necessity of safe processing of phosphogypsum on the surface of the tailings "Dniprovske" with its simultaneous replacement by a new soil cover is proved.

Allergy and Household Living Conditions among Adolescents Living near Gold Mine Tailing Dumps in the Gauteng and North West Provinces of South Africa.

This quantitative exploratory baseline study aimed to investigate whether allergy among adolescents was associated with household living conditions, including living near gold mine tailing dumps in South Africa. A questionnaire based on the International Study of Asthma and Allergies was used to collect information on allergy and household risk factors among adolescents (n = 5611). A chi-square test was applied to determine the relationship between community (exposed/unexposed) and confounding variables. Crude and adjusted odds ratios (ORs) and 95% confidence intervals (CI) were calculated using univariate and multiple logistic regression analysis (LRA) to estimate the likelihood of having doctor-diagnosed allergies. The overall prevalence of doctor-diagnosed allergies was 25.5%. The exposed communities had a higher prevalence of doctor-diagnosed allergies (26.97%) compared with the unexposed (22.69%) communities. The study found an association between doctor-diagnosed allergy and having fungus in the house, being female, currently having pets in and around the house, residing in the community for more than three years and living in communities located close to gold mine tailing dumps. Actions to implement buffer zones between gold mine tailing dumps and communities would support Sustainable Development Goals 3 (health) and 11 (sustainable cities and communities), while failing to address the current potential identified risk factors may pose a significant public health challenge. Local policymakers should also apply the precautionary principle to protect the health of children, especially with the location of human settlements relative to air pollution sources.

РЕПОПУЛЯЦИЯ ГОРНЫХ ПОСЕЛЕНИЙ: ПРОБЛЕМЫ И ПЕРСПЕКТИВЫ (На примере РСО-Алания)

Introduction. For North Ossetia, where about half of the territory is occupied by mountains, the problems of the mountain population and settlement are of particular relevance. They are becoming even more relevant now, in connection with the intensification of economic activity in the mountains, the construction of a cascade of Zaramag HPPs, the implementation of the Mamison project, the optimization of recreational activities, the development of environmentally friendly cattle breeding, fish farming, crop production, etc. Settlement began to rebuild to meet the needs of the economy, the infrastructure began to improve (gasification, electrification, computerization, etc.), the population again reached for the mountains. Research methods. The study of mountain settlement in the North Caucasus has begun relatively recently. The first works appeared in the 1990s. They covered the territory from Dagestan to Adygea. Mountain settlement in Dagestan was studied by Sh.S. Muduev [4], in Kabardino-Balkaria by A.E. Zelenskaya [5], in Adygea by F.V. Tlehuray [6]. A.D. Badov [7–9; 20]. Studies of mountain settlement were also carried out by Yu.P. Badenkov [1; 10; 11], V.S. Belozerov [12], P.P. Turun [13] and others. Research results. Currently, there is a stabilization and even a slight increase in the population in the mountainous part of North Ossetia. At the same time, in summer, the number of the living population increases significantly due to the arrival of summer residents and tourists. The number of summer residents has increased significantly over the recent period, especially in the Kurtat gorge. However, some problems of both demographic and ecological character are revealed. Thus, in a number of villages there is a significant disproportion in the sex structure of the population, which negatively affects the marriage rate of the population [5]. The dumps in the mountains have not been liquidated yet, the tailing dumps have been reclaimed with design errors and imperfections.

Modeling the Process of Thawing of Tailings Dam Base Soils by Technological Waters

The storage of wastes from mining and mineral processing plants in the tailing dumps in regions with cold climates has a number of environmental consequences. Interactions of water with tailings in cold climates often lead to the thawing of permafrost soils, formation of technogenic thawing zones, and leakage of drainage waters. In the case of fault zones development in these areas, technogenic solutions are often filtered outside the tailing dump, promoting further development of filtration channels. In order to prevent leakage of solution from tailing dumps over time, it is necessary to determine the thawing zones and prevent the formation of filtration channels. In the case of the formation of a filtration channel, it is necessary to know what rate of rock thawing occurred near the formed filtration channel. In this study, for the tailing dump of a diamond mining factory, we calculated two exothermic effects: (1) due to physical heating of dump rock by filtering industrial water with temperatures from 2 to 15 °C through the rock; and (2) due to the chemical interaction of industrial water with the dam base rock. The amount of energy transferred by the water to the frozen and thawed rock over 10 years was calculated using thermophysical modeling and was 207.8 GJ and 8.39 GJ respectively. The amount of energy that the rock received during the ten-year period due to dissolution of the limestones and equilibration of solutions was calculated using thermodynamic modeling and was 0.37 GJ, which is 4.4% of the average amount of energy, expended on heating the thawed rock (8.39 GJ).

The rooting, survival and growth of woody species on tailing dumps in the limestone quarry “Lafarge ciment”

The rooting, the survival and dynamics of growths in the height and after the diameter of the seedlings, of a range of woody species, had investigated on the freshly formed sterile dump limestone quarry „Lafarge Ciment”. The seedlings of the woody species had a relatively good rooting (69-99%). A high degree of rooting can be ensured as a result of the maintenance of forest crops. After planting, the young seedlings must be cared for by hoeing as many times as necessary in order to control the weeds and maintain moisture in the soil, which increases the survival of the seedlings. Tree species have been characterized by a different growth rate. Acacia has showed a very rapid increase in height, but the black pine has been characterized by a slow growth. Acacia being a fast-growing species and unpretentious to the mineral elements in the soil can be used to afforest the limestone quarry land. In the fi rst year after planting, the young seedlings, otherwise sensitive to the action of the environmental factors, had an increase in height and in diameter slow and uneven. In the years that followed, the seedlings became more viable and less infl uenced by local and temporal fl uctuations of environmental factors.