Mineral Processing Waste Research Articles

Distribution of Heavy Metals in the Surrounding Mining Region of Kizhnica in Kosovo

This study investigated the distribution of heavy metals in agricultural soils in the vicinity of three large mining landfills of the Kizhnica mine in the Republic of Kosovo. The mining sector is one of the most important sectors of Kosovo’s economic development, and the Kizhnica mine is one of the most important ore producers in Kosovo. Besides the positive aspects, the development of production also has some negative side effects, such as the generation of industrial waste and the possible contamination of surrounding areas, including agricultural land. Therefore, ten sampling sites were selected in the vicinity of the Kizhnica mine. These sites were characterized and assessed as the most important due to the anthropogenic impact of mineral processing and open-tailing waste deposits in Kizhnica. The concentration of Pb, Zn, Cu, As, Cd, Ni, Mn and Sb in the selected samples was determined using inductively coupled plasma–optical emission spectrometry. The data obtained were used to create geochemical maps and calculate the contamination factor, pollution load index and geoaccumulation index. Cluster analysis, Pearson correlation coefficient and air spatial distribution patterns using the air dispersion model were used to evaluate within the area. The results showed that heavy metal levels are influenced by the anthropogenic nature of pollution, confirming a current ecological threat from mining activities in the region. In order to improve waste management, reduce the hazardous impacts of mining and contribute to the sustainable development of the region, the potential reuse of the deposited waste material in the construction industry is proposed.

The roles of rare and abundant microbial species in the primary succession of biological soil crusts are differentiated in metal tailings ponds with different states

Tailings ponds formed by long-term accumulation of mineral processing waste have become a global environmental problem. Even worse, tailings ponds are often simply abandoned or landfilled after they cease to be used. This allows pollution to persist and continue to spread in the environment. The significance of primary succession mediated by biological soil crusts for tailings pond remediation has been illustrated by previous studies. However, the process of primary succession may not be the same at different stages during the lifetime of tailings ponds. Therefore, we investigated the environmental differences and the successional characteristics of microbial communities in the primary successional stage of tailings ponds at three different states. The results showed that the primary succession process positively changed the environment of tailings ponds in any state of tailings ponds. The primary successional stage determined the environmental quality more than the state of the tailings pond. In the recently abandoned tailings ponds, abundant species were more subjected to heavy metal stress, while rare species were mainly limited by nutrient content. We found that as the succession progressed, rare species gradually acquired their own community space and became more responsive to environmental stresses. Rare species played an important role in microbial keystone species groups.

Numerical modeling of the wind regime on the beaches of the wash of the artificial storage facilities for mineral processing waste

A 2D numerical model has been developed to estimate the airflow velocity field when flowing around the dam of an artificial storage facility for mineral processing waste. To solve the aerodynamic problem of determining the air flow velocity field when flowing around such hydraulic structures with a complex geometric shape, a potential motion model was applied. The numerical integration of the equation for the velocity potential is carried out using the Liebman method. The geometric shape of the tailings storage facility is formed in a discrete model using the marking method. A computer program was created to implement the developed numerical aerodynamics model. Based on the processing of the results of computational experiments, coefficients were obtained that allow us to quickly determine the value of the air flow velocity at the beginning and end of the tailing pond beach, i.e. in the area of the most intense dust emission. This allows for a quick prediction of the risk of dust air pollution at different tailing pile heights.

Removal of Copper (II) from Mining Waste Water by Adsorption onto Activated Carbons Produced from Hazelnut Shell

Mining wastewater is one of the most important environmental problems today because of the heavy metal ions they contain. Wastewaters containing heavy metal pollution are generally acidic waters with low BOI (Biochemical oxygen demand) value. Various processes such as mineral processing waste disposal, illegal mining, domestic waste disposal, and others result in the release of heavy metals into the waters. One of the heavy metals that cause problems in terms of environmental pollution is copper. Copper metal is commonly found in metal and metal plating industry wastewater. Although metal industry wastewater is low in quantity, they are toxic waste. For this reason, industrial wastewater must be treated before being discharged into the receiving environment. In this study, the amount of Cu in wastewater of the mining operation in Gümüşhane was determined. Heavy metal pollution was eliminated with an adsorbent produced from agricultural biowaste. It has been tried to determine the amount of adsorbent, contact time, and treatment efficiency of wastewater at different pHs of activated carbon produced by chemical activation. As a result, an average of 88.7% efficiency was obtained with activated carbon activated with KOH, while 22,4% copper removal efficiencies were obtained with raw material (hazelnut shell) used without activation. It was determined that the appropriate working pH was 5,0; the amount of adsorbent was 0.05 g and Qmax 121,2. As a result, in this study, very low-cost adsorbents were produced using waste hazelnut shells, and a biotechnological approach was proposed to clean copper-containing wastewater.

Substantiation of environmentally safe modes and parameters of operation of mineral processing waste storage facilities

The subject of the paper is the modes and parameters of operation of mineral processing waste storage facilities. Liquid waste storage facilities that accumulate processing products and mine water from several mining enterprises are considered, taking into account climatic factors of influence, technological limitations on the volume of waste. The analysis of the main results shows that environmental safety in the operation of waste storage facilities is based on two principles: to prevent waste overflow over the edges of the embankment dam and to provide a protective layer of liquid over the bottom, which is formed from particles of dusty and clay fractions. The purpose of the study is to scientifically substantiate the possible modes of operation of liquid waste storage of mineral raw materials processing and mining, as well as the creation of methods for calculating their maximum possible volumes entering the storage during the year, taking into account environmental safety. The study used the methodology of logistic systems, in the framework of which storage facilities are considered as a node of accumulation, and its model includes a system of equations describing the height of the water mirror and the bottom level depending on the volume of placers from the water volumes that entered and withdrawn from it during the period of operation, which is analyzed, taking into account the geometric features of the storage bowl. As a result, a mathematical model of liquid waste storage, which accumulates processing products and mine water from several mining enterprises, has been developed, taking into account climatic factors of influence, technological limitations on waste volumes. This model allows to determine the level of the free surface mirror in any month of the year, as well as to calculate changes in the current height of the free surface mirror in the storage for any period of time. On the basis of these formulas and ecological safety requirements at operation of artificial storages of wastes from processing of mineral raw materials the restrictions on volumes of wastes which enter the storage during a year, or during spring months have been received. The use of these restrictions allowed to determine and justify the rational values of capacities on salable concentrates of mining enterprises, duration of their downtime for a certain period of the year. Keywords: storage of mineral processing waste, height of the water mirror, environmental safety of operation.

Electrochemistry of Sulfides: Process and Environmental Aspects

One of the main sources of non-ferrous and precious metals is sulfide ores. This paper presents a review of the existing literature on the electrochemical properties of some of the most common industrial sulfides, such as pentlandite, chalcopyrite, sphalerite, galena, pyrrhotite, pyrite, etc. The study results of the surface redox transformations of minerals, galvanic effect, cathodic oxygen reduction reaction on the surface of sulfides are presented. The electrochemical properties of sulfide minerals are manifested both in the industrial processes of flotation and hydrometallurgy and in the natural geological setting or during the storage of sulfide-containing mining, mineral processing, and metallurgical industry waste.

Recycling and Reuse of Mine Tailings: A Review of Advancements and Their Implications

Mining is an important industry, accounting for 6.9% of global GDP. However, global development promotes accelerated demand, resulting in the accumulation of hazardous waste in land, sea, and air environments. It reached 7 billion tonnes of mine tailings generated yearly worldwide, and 19 billion solid tailings will be accumulated by 2025. Adding to this, the legacy of environmental damage from abandoned mines is worrying; there are around 10,000 abandoned mines in Canada, 50,000 in Australia, and 6000 in South Africa, as well as 9500 coal mines in China, reaching 15,000 by 2050. In this scenario, restoration techniques from mining tailings have become increasingly discussed among scholars due to their potential to offer benefits towards reducing tailing levels, thereby reducing environmental pressure for the correct management and adding value to previously discarded waste. This review paper explores the available literature on the main techniques of mining tailing recycling and reuse and discusses leading technologies, including the benefits and limitations, as well as emerging prospects. The findings of this review serve as a supporting reference for decision makers concerning the related sustainability issues associated with mining, mineral processing, and solid waste management.

Improving the Efficiency of Forestry Measures for Carbon Storage by Reclamation and Phytomelioration of Lands Technogenically Contaminated with Toxic Tailing Wastes

The article presents the results of multi-year research on technogenic pollution of biosphere components with wastes of cassiterite-sulfide formation processing. The areas of mainly Far Eastern taiga and Priamurye-Primorye coniferous-broad-leaved forest in the Far Eastern Federal District (FEFD) of Russia have been withdrawn from the forest land fund for their development. As a result, large amounts of mining waste have been accumulated, with negative impact on forest ecosystems. In this regard, the aim of the study was to substantiate forestry measures for improving their efficiency by reclamation and phytomelioration of technogenically contaminated lands with toxic mineral processing waste to accumulate carbon stock. The analysis and systematization of the literature and patent search materials testify that the article is devoted to the actual problem of carbon stock accumulation within the impact boundaries of the technogenic system by reclamation and phytomelioration. These problemsr in the conditions of mining enterprises of the Far Eastern Federal District of Russia are poorly studied. It is shown that the mineral development by the mining enterprises closed in the last century led to the large-scale destruction of forest communities. Methods of reproduction of productivity of technogenic polluted lands using bioremediation which novelty was confirmed by Patents of the Russian Federation are developed. By means of their reclamation and phytomelioration an increase in forestry measures and accumulation of carbon stocks in the reclaimed lands was achieved by more than 2.5 times in comparison with the nonreclaimed lands.

Mercury as an indicator of geological and environmental risks in the development of various mineral raw materials

Mercury is a highly toxic pollutant of the environment, and a quantitative assessment of its emission and migration in the technogenic transformation of mining regions is vital. The presented study focuses on the features of mercury concentration in the natural mineral raw materials, commercial products and processing waste by the example of mercury-containing copper pyrite deposits in the Urals. Mercury (its quantitative indicators) is used as a reliable element-tracer of the evolution of the technogenic system: mineral raw materials – subsurface use wastes – environmental components – food products – the human body. Such integrated approach is recommended for optimizing the forecasting, assessment and management of geological and environmental risks, as well as for the geological and environmental monitoring of the modern mining engineering system.

Problems and prospects for forest restoration, conservation and protection by reclamation during mineral development in the far eastern federal district

The article presents the results of the research of increasing the forestry measures efficiency by reclamation and phytomelioration of land sites under negative technogenic impact within the influence of mining enterprises in the Far Eastern Federal District of Russia. The land sites withdrawn from the forest land fund in the process of mineral development are intensively polluted by toxic tailing dumps. In this regard, the aim of the study was to assess the impact of tailing dumps on the current state of forest vegetation, and to identify the prospects for restoring the productivity of technogenically polluted lands and forest protection by reclamation and phytomelioration to ensure environmental safety of mineral processing waste. It was found, that strengthening of the technogenic environmental impact, including the forest communities, caused tense ecological situation in the adjacent territories. The regularities of forest ecosystems technogenic pollution, as well as the problems and prospects for their restoration, conservation and protection were revealed. Proposals to enhance the efficiency of forestry measures using reclamation and phytomelioration of technogenic polluted forest areas have been developed, its novelty has been confirmed by the Patents of the Russian Federation.

Using multivariate statistical analysis in assessment of surface water quality and identification of heavy metal pollution sources in Sarough watershed, NW of Iran.

The Sarough watershed in NW Iran hosts a large amount of mineral occurrences and ore deposits which may be considered as the source of heavy metals in the region. The area has been studied previously; however, the methodology of this paper was less focused on previous studies. This study aimed to assess water quality, determine the spatial distribution pattern, and identify the sources of heavy metals in the main tributaries of Sarough watershed using pollution indexes, multivariate statistical methods, and processing data by geographic information system. Totally, 51 water samples were collected along the main rivers to determine the concentrations of heavy metals by ICP-MS. Regarding the drinking water, agriculture, and freshwater aquatic life guidelines, the rivers were assumed unsafe considering most of toxic elements' content, especially As. The mean values for heavy metal pollution indexes (HPI: 237.32) and metal indexes (MI: 25.37) indicated the intensive heavy metal pollution. The cluster analysis categorized the 51 sampling sites into four clusters with respect to pollution level. The results obtained from the Kruskal-Wallis and multiple comparison tests had the harmony with the results of CA in introducing the most impacted sampling sites and the parameters responsible for water quality degradation. The results of PCA showed the maximum similarity between As, Sb, Se, Fe, and Mn as well as base metals which was attributed to anthropogenic input from mining and mineral processing wastes. Association of Cr and Ni may suggest a lithology source (weathering of metamorphosed ultramafic outcrops). The maps prepared in the GIS system showed the spatial distribution pattern of toxic elements with maximum values nearby mining sites which decreases gradually toward downstream areas. Finally, the results showed that the Sarough River and its tributaries are influenced by high concentrations of heavy metals from the drainages of mining and ore processing sites and naturally occurring metal loadings as well as the geogenic sources such as weathering of geologic formations and hot springs.

Indicators and Factors Resulting in Crisis Phenomena Related to the Environment Hazard of Accumulated Mineral Processing Wastes at Closed Mining Enterprises

The article presents the results of multi-year research within the limits of closed mining enterprises impact in the Far Eastern Federal District (FEFD). In the last century, here, a large amount of sulphidized toxic mineral processing wastes, stored in tailing dumps, negatively affecting the environment, was accumulated. Unfortunately, their conservation and reclamation have not been carried out; they pose a huge threat not only to the ecosphere, but also to public health. Therefore, the aim of the study was to identify the indicators and factors causing crisis phenomena related to environment hazard of accumulated toxic waste and to substantiate the possibility of reducing their negative impact on biosphere components and human health. Natural and mining technogenic systems formed in the last century by the activity of closed mining enterprises in the Amur River basin, having biosphere importance, were the object of the study.The following methods were used: systematization, scientific forecasting, physical and chemical, biological methods, as well as mathematical modeling, GIS-technologies, etc.The article substantiates the necessity of effective solution of the above problem. The present state of tailing dumps has been studied and it has been established that the waste is of the second class (high-hazard). It is revealed that the level of technogenic pollution of environment objects exceeds regional background indicators in dozens (up to 28-46) times, and MPC - in hundreds, up to 225 and more, times. It was shown that the surface of the tailing dumps has not overgrown naturally for 30 years. The results of the patent search and our own experimental research allowed us to develop technological solutions to ensure environment safety of mineral processing toxic wastes. The principles of ensuring environment safety of tailing dumps containing toxic wastes have been developed. New methods of their surface productivity replenishment using innovative approaches have been created, their novelty was confirmed by the Patents of the Russian Federation.

Горные работы при строительстве транспортных коридоров

Research objective: analysis of waste disposal issues in the mining and mineral processing industry of the Russian Federation. Research methodology: economic and environmental challenges concerned with mining and mineral processing waste in dumps and tailings were analysed. Results: an option is proposed to dispose of the waste rock generated by the mining and processing industry by using it for construction of railways and motor roads. This technology makes it possible to avoid construction of quarries and temporary settlements for their development along the road route, which will decrease the environmental impact and significantly reduce the time and cost of road construction. Conclusions: The proposed technology helps to achieve a significant economic effect (no costs for transporting materials from remote areas of the country), reduce the adverse environmental impact of mining operations and, in the long term, prevent dump formation.

Assessment of environmental hazard of accumulated mineral processing waste of closed mining enterprises in the Amur river region and Primorye

The subject of research was technogenic waste systems formed in the last century due to the activities of presently closed mining enterprises in the Amur River Region and Primorye of the Far Eastern Federal District of the Russian Federation. Experimental studies allowed to establish that toxic sulphidized mineral processing waste accumulated for the 20th century in tailings storage facilities (TSF) in large quantities produce negative impact on the environment. It was revealed that their conservation and reclamation were not carried out. However, they pose huge threat not only to the environment, but also to public health. In this regard, the research goal was to assess environmental hazard of the accumulated toxic waste and substantiate the possibility of mitigating their negative impact on biosphere components and human health. Based on the research goal, the following tasks were set: 1) analysis and generalization of the existing experience of studying the problem in Russia and abroad; 2) identification of the main sources of crisis situations at closed mining enterprises, indicators and criteria for as sessing the environmental hazard of the accumulated mineral processing waste; 3) assessment of the environmental hazard of the accumulated mineral processing waste; 4) development of principles and measures aimed at ensuring environmental safety of TSF comprising toxic waste. The following methods were used: physical-chemical, bio logical, as well as mathematical modeling, GIS technologies, etc.Based on the study of the TSF current state, assessment of the level of technogenic environment pollution, and patent search, the authors substantiate the need for effective solution to this problem. It was found that the waste belongs to the second hazard class (highly hazardous). The excess of 4 to 46 times above the regional background indicators (metal concentrations), and more than 200 times above MPC was revealed. It has been proven that the TSF surface does not naturally run wild for 30 years. Patent search and our own experimental research allowed developing measures to ensure environmental safety of sulfidized tin ore processing waste, novelty of which was confirmed by patents of the Russian Federation.

Assessment of Air Basin Pollution within the Limits of the Technogenic System (Dalpolimetall) Impact Using Mathematical Modeling

The article presents the results of research of air technogenic pollution within the limits of the natural-mining system impact formed by Dalpolimetall mining-metallurgical enterprise activity in the Primorsky Krai. Its development is due to intensive polymetallic ore development and accumulation of significant amount of its processing toxic waste, stored in two tailing dumps, located at the area of 80 hectares, withdrawn from the forest land fund, their volume being 32.2 mln tons. The studies found that in general the waste on the surface of the tailing dump is of the second class of danger (high-hazard), which is currently in the stage of active formation, being a powerful negative impact factor for the environment. The study of the air pollution degree, carried out by gas survey on transversal profiles, shows that the largest number of different heavy metal compounds is contained in the dust selected for analysis near the tailing dump. Its maximum concentration, reaching 86 MAC, was revealed near the concentrating factory. The average concentration throughout the territory of the object under study is 38 times higher than the allowable limits. High concentrations of carcinogenic elements (arsenic, chromium and antimony) are found in the dust samples. The assessment of the air basin impact carried out by the method of computation monitoring using GIS-technology and the Ecologist Software, allows to assert that its pollution by mineral processing waste within the limits of Dalpolimetall impact in Dalnegorsk refers to an extremely high level for toxic dust, heavy metal compounds and sulfate-ion aerosols. The results of the research of air basin technogenic pollution using mathematical modeling allowed to reveal spatial and temporal regularities of the main pollutants distribution.

Геоэкологические и организационно-экономические проблемы переработки горнопромышленных отходов в Российской Федерации

Геоэкологические и организационно-экономические проблемы переработки горнопромышленных отходов в Российской Федерации

Recovery of valuable metals from mining and mineral processing waste

Ammonia-thiosulfate-copper leaching, aided by a direct current electrochemical impact, is proposed to extract gold (Au), silver (Ag) and copper (Cu) from old flotation tailings mixed with waste rock. Over 80 % of Au available in the waste material and over 75 % of Cu and Ag were extracted into the pregnant leach solution (PLS) at room temperature. Electrowinning from that PLS recovered around 92 % of Au and Cu, and about 87 % of Ag in the cathode deposit that is suitable for further metallurgical refining. The results are better, compared to leaching in the same system but without electrochemical impact and at air addition. The proposed direct current aided method is promising and more environmentally friendly compared to cyanide and even to sodium thiosulfate leaching.

Ecobiotechnology in the process of industrial wastewater treatment of the closed mining enterprise as a guarantee of environment safety

The report presents the results of long-term studies of the problem of ecological and chemical assessment of the impact of mineral processing waste in the form of pulp on the ecosphere, including aquatic ecosystems, and the development of bioengineering technologies (bioremediation) aimed at reducing their negative impact on the environment in the Primorsky territory. In the last century at the concentrating plant of the closed Khrustalnensky GOK mining enterprise a chemical method was used to treat industrial wastewater, a degree of which was no more than 75%. It is shown that pollutants discharged into water bodies after chemical treatment, which have a general toxic, carcinogenic and mutagenic effect, still pose a great threat to the ecological balance of natural systems. The studies show that there was intense pollution of ground and surface water, soil and vegetation, exceeding the regional background indicators up to 9 or more times within the boundaries of the anthropogenic system impact. Therefore, in the study area it is necessary to ensure environmental and social safety of industrial effluents by improving their treatment technology. In this regard, the aim of the research was not only to assess the extent of the negative impact of beneficiation mineral toxic wastes in the form of pulp to the ecosphere, but also in the development of ecologically safe biotechnological method of purification industrial wastewater by biodegradation, biooxidation and biosorption from solutions using the metabolic potential of biological systems (hydrophytic plants). Based on the purpose, the following tasks are defined: 1. To analyze and summarize the literature on the problem of industrial wastewater treatment using biological methods; 2. To study the composition and properties of industrial wastewater in the form of pulp and assess their impact on the environment; 3. To investigate ecological and biological features of little Duckweed as a possible concentrator of heavy metal compounds; 4. To develop a biotechnological solution for industrial wastewater treatment using bioremediation (higher aquatic vegetation, Duckweed). Experimental studies have proved the effectiveness of the biological systems metabolic potential (little Duckweed) to ensure the normative quality of treated wastewater by the example of a closed mining enterprise in the Primorsky territory (Khrustalnensky GOK). The scientific novelty of the proposed method is confirmed by a Patent of the Russian Federation (2014).

Heterogeneous Nanomagnetic Catalyst from Cupriferous Mineral Processing Gangue for the Production of Biodiesel

The commercialisation of biodiesel as an alternative energy source is challenged by high production costs. The cost of feedstock, catalyst and separation of the dissolved catalyst (homogeneous catalyst) from the product are the major contributors to the total manufacturing cost of biodiesel. This study investigated the potential of a heterogeneous catalyst produced from mineral processing waste for biodiesel production. Tailings from the concentration of cupriferous minerals served as the starting material for synthesis of the catalyst. The nanomagnetic catalysts were prepared using co-precipitation (CMCO) and sol-gel (CMSG) methods, combined with zero-valent iron nanoparticles (ZVINPs) to form a hydride catalyst (CMSG/ZVINPs). Catalyst properties were assessed using SEM, TEM, BET and EDX. The catalyst activity was enhanced by a large number of basic sites that were afforded by the presence of calcite and magnesite. Good surface areas and particle sizes of 58.9 m2/g and 15.4 nm, and 52.6 m2/g and 16.9 nm were observed for the catalysts that were prepared using the CMSG and CMCO methods, respectively. 173 emu/g mass magnetisation was obtained for CMSG/ZVINPs, which was sufficient for the catalyst to be regenerated and reused for biodiesel production by exploiting the magnetic properties. The maximum yield obtained with this catalyst was 88% and an average of 27% decrease in biodiesel yield was observed after four reaction cycles. The physicochemical properties of the biodiesel produced complied with the ASTM standard specification. The results showed that mineral processing tailings are a viable starting material for catalyst preparation in biodiesel production.

Environmental and Business Challenges Presented by Mining and Mineral Processing Waste in the Russian Federation

Using Murmansk Region, one of Russia’s largest mining regions, as a case study, this paper examines the environmental safety challenges arising in the storage of mining and mineral processing waste (MMPW). It was found that MMPW causes environmental damage even after the deposit’s exhaustion. While being stored, the MMPW composition experiences a major change in the process properties of the recoverable minerals. As a consequence, the potential value of the MMPW as a mineral resource falls. Imperfections of the regulatory framework, leading to a higher unit cost of recovery and a reduced profitability of MMPW processing, are demonstrated. Potential amendments to the Russian laws are proposed in order to make MMPW processing commercially more viable.