Substandard Ores Research Articles

Studying the Process of Phosphogypsum Recycling into a Calcium Sulphide-Based Luminophor.

Currently, one of the most important problems of environmental protection is the deep and complex processing of mineral raw materials. This problem is especially relevant when processing substandard ores and production waste, one of which is phosphogypsum. This study examines the process of CaSO4/CaS composite material formation during the reduction of phosphogypsum with citric acid. The composite structure formation mechanism is proposed. The resulting materials are characterized using various methods, including X-ray diffraction (XRD), transmission electron microscopy, the Scherrer method, thermogravimetric analysis (TGA), and FT-IR spectroscopy. The reduced sample emits orange radiation in the range of 500-750 nm with a quantum yield of 0.17. Experimental results showed that the sample decomposition process in the solid state consisted of two components with a predominant contribution from the long-lived component (~46 ns). The optimal conditions for producing luminescent materials by reducing phosphogypsum with citric acid were determined: a heat treatment temperature of 1073 K, a holding time of 60 min, and a reducing agent mole fraction of 37%. It was found that an increase in temperature with a simultaneous decrease in heat treatment time, as well as a decrease in temperature with a simultaneous increase in heat treatment time, led to a decrease in the luminescent properties of the synthesized material compared to optimal values. The results can be used to develop technology for recycling large-tonnage waste from the chemical industry into luminescent materials.

Поэтапная комбинированная разработка золоторудных месторождений

Introduction. It is noted that in the Russian gold mining industry, the profitability of gold production is associated with the development of technologies for leaching it from substandard ores and enrichment waste. It is shown that the priority aspect of the development of substandard raw materials is to increase the yield of more gold with acceptable additional investments, predicted based on the analysis of the production function in the models of economic growth of enterprises. The purpose of the study is to substantiate the possibility of increasing the completeness of subsurface use during the phased development of reserves with a combination of chemical and mechanical extraction processes. Methods of achieving the goal include the use of literary and patent sources, production experience, laboratory and field experiments, modeling and technical and economic calculations. Results. The relevance of the development of a new raw material base is shown by the example of the reserves of the Sadonsky poly-metallic deposit. The information on the operations of hydrometallurgical and heap leaching of gold with bringing to the final product is detailed. An algorithm is proposed for the selection of options for the development of gold bulls. A model is presented to calculate the efficiency of phased field development over time. An optimized scheme of heap leaching of gold and indicators of gold extraction are presented. The scheme of electrochemical leaching of gold from sulfur-containing ores is recommended. The factors of the impact of mining on the environment at three stages of development are systematized. A model is presented for determining the efficiency of utilization of enrichment tailings and profits from the extraction of gold from enrichment tailings and metallurgy, taking into account environmental damage. The results of calculating the efficiency of gold extraction at the factory and leaching in blocks and cubes are presented. It is shown that the end-to-end metal recovery coefficient by leaching is comparable to the traditional technology of processing balance reserves. It is proved that when combining technologies at the stages of field development, a larger amount of metal is extracted from the subsurface. Conclusion: with a small increase in infrastructure modernization costs, combining traditional technology and leaching technologies, more metal is extracted from the subsurface.

К ПРОБЛЕМЕ ВЫЩЕЛАЧИВАНИЯ МЕТАЛЛОВ ИЗ НЕКОНДИЦИОННОГО СЫРЬЯ

The experience of metal extraction by infiltration leaching in underground blocks and mechanochemical leaching in a disintegrator is described. An assessment of the effectiveness of new metal mining technologies with the intensification of technological processes is given. It is shown that the involvement of substandard ores and enrichment tailings in the production strengthens the raw material base of the industry and reduces the burden on the environment.

REHABILITATION OF MAN-MADE FORMATION OF ABANDONED COPPER PYRITE DEPOSITS ON THE EXAMPLE OF LEVIKHINSKY MINE (MIDDLE URALS)

Link for citation: Rybnikova L.S., Rybnikov P.A., Navolokina V.Y. Rehabilitation of man-made formation of abandoned copper pyrite deposits on the example of Levikhinsky mine (Middle Urals). Bulletin of the Tomsk Polytechnic University. Geo Аssets Engineering, 2023, vol. 334, no. 8, рр. 137-150. In Rus. The relevance of the research is related to the need to rehabilitate of abandoned copper pyrite deposits affected by acid mine waters and justify measures to clean up the existing clarification pond. The main aim is to study the sludge composition and justify the measures to reduce the environmental load on the hydrosphere. Objects: clarification pond and neutralization sludge of the Levikhinsky copper pyrite mine acid mine waters. Methods. Laboratory studies of water and bottom sediments were carried out using atomic emission and mass spectral analysis; methods of flame emission spectrometry, flame atomic absorption, photometric method with Nessler's reagent, titrimetric, mercumetric and potentiometric methods; mass spectrometry with ionization in inductively coupled plasma and gravimetric method. Results. Sludge samples are dominated by sulfates (gypsum and bassanite), iron oxides and hydroxides (goethite), carbonates (calcite), clay minerals (mainly hydromica) and chlorine-containing salts (carnallite). The chemical composition of the sludge is dominated by oxides of iron, sulfur and calcium. The analysis of water and acid extracts showed that up to 24 elements belonging to hazard classes 2, 3 and 4 can be leached from the sludge in concentrations exceeding the maximum allowable values for fishery water bodies. Several options for the use of sludge from the clarification pond were analyzed: reclamation of waste rock dumps and substandard ores; backfilling of mined-out area of quarries; production of building materials; extraction of components; storage of sludge in geotubes (Geotube). The most rational is the disposal of sludge as the production of building materials on the basis of a public-private partnership, the implementation of which will allow the state and the private sector to derive mutual benefit.

Modern Technologies Providing a Full Cycle of Geo-Resources Development

Resource-dependent countries and economies are found to be particularly sensitive to global shocks. A unifying parallel is drawn between resource-dependent countries and regions with depleted mineral resources. The objective factors of losses of accessed reserves are analyzed. A unifying parallel is drawn between sub-standard ores and industrial waste. The paper proposes shifting geotechnology development from simple mineral extraction towards technologies that provide a full cycle of geo-resources development. A radical way of ensuring a full cycle of geo-resources development is the involvement of sub-standard ores and industrial waste in a closed processing cycle. The utilization of industrial waste without a valuable component extracting or reducing a harmful component to a background value is palliative. A comparative description of various technologies that allow extracting valuable components from sub-standard ores and industrial waste is made. The paper proposes a variant of chemical–physical technology that makes it possible to extract a valuable component from industrial waste to a minimum value. The activation of industrial waste with a disintegrator before a chemical extraction significantly increases the yield of a valuable component from 2.6 to 218.5%. A differentiated approach is needed regarding the choice of leaching solution, its percentage, as well as the leaching method and the need for activation processing of valuable components and industrial ones. The combined highly efficient physical–chemical and physical–technical technologies will ensure the maximum extraction of the valuable component from 52.6 to 98.8% in the full cycle of natural and industrial geo-resources development.

Modernization of technologies for the development of ore deposits using substandard raw materials

The purpose and relevance of the work. The article is devoted to the urgent problem of strengthening the mineral resource base of industry by involving substandard ores and tailings of their processing in the production. The purpose of the research is to find ways to modernize field development technologies. Methodology. According to the reporting data, a critical analysis of the completeness of the extraction of reserves and the effectiveness of the applied development systems is carried out. Based on the analysis of technology options, an engineering forecast of the ways of development of depressed enterprises is made. Results and scope. A reference is given on the history of ore development in the regions. The reason for the low rates of extraction from the subsurface is the discrepancy between the x development technologies and the principles of resource conservation with the transfer of reserves to the inactive category. The role of SCGMI in the theory and practice of lead and zinc leaching is shown. The information about the project of development of a deposit of balance ores by leaching is given. A reference is given on the practice of developing the Bykogorskoye deposit by leaching off-balance ores. The explanation of the increased losses and dilution of ores and the negative impact on the environment is given. The indicators of the quality of mined ores are given. A scheme is recommended for the development of North Caucasian deposits by leaching ores in blocks and tailings of enrichment in disintegrators. Quantitative indicators of metal extraction into solution are given. The results of the study may be in demand in the extraction of metals from technologically opened ores. Conclusions. The conditions of the regions of the North Caucasus correspond to the combined technology of the development of fertilizers with the extraction of metals from rich ores at the plant and the leaching of poor ores in blocks and tailings of enrichment in activators of the disintegrator type

К проблеме разработки потерянных руд Садона (РСО-Алания)

The relevance of the work is explained by the need to restore the lost potential of polymetallic extraction from the deposits of the Sadonsky ore node using the existing infrastructure and favorable geographical conditions for yearround operation. The purpose of the work. Theoretical and experimental substantiation of the technological possibility and economic feasibility of converting traditional development technologies to technologies for obtaining metals and other marketable products by leaching substandard metal-containing raw materials. Research methods: generalization, systematization, and analysis of theoretical and experimental studies with the acquisition of a data bank for the design of technologies for the extraction and processing of remaining reserves in the subsurface and man-made reserves on the Earth’s surface. Research results. The concept of environmental protection and resource-saving technology for the development of deposits of the type under consideration is formulated. The volume of potentially possible substandard ore reserves and mining and processing waste in the regions of the North Caucasus is estimated. The results of pioneering studies of the processes of extracting metals from ores, industrial effluents and man-made raw materials, including the processing of non-conditioned ores and their enrichment waste in a disintegrator using mechanochemical activation of the metal extraction process, are presented. The prospects of using innovative technologies in the region are assessed. It is shown that the prospects for resuscitation of mining production depend on the effectiveness of combining technologies and minimizing losses when using the available raw material base, determined by economic and mathematical modeling taking into account the environmental component.

Nickel Group and Its role in the history of soviet non-ferrous metals industry

The work undertaken by the research team Nickel Group, which was active at the Leningrad Mining Institute during the period of the first Five-Year Plans and the 2nd World War, played a major role in establishing the production of high-quality additives for armour and shell steels in the USSR. Such additives were obtained from any substandard ores and semi-finished products using only domestic machinery. In an extremely short period of time, the Group managed to develop original processes for extracting nickel, cobalt, platinoids and molybdenum, which were absolutely unique in the world and were quickly adopted by the industry. The main source of information about the Group’s activity includes biographies of its most prominent members – N.P. Aseev, N.S. Greyver, K.F. Beloglazov, I.N. Maslenitskiy et al. Some information can also be found in the historical essays that were prepared to mark the Leningrad Mining Institute’s anniversary. The author used a wide range of materials from official and private sources, as well as from the history fund of the Museum of Mining, and he was the first to show the role of Nickel Group in the emergence of non-ferrous and rare metals industry in the USSR, which did not only come to developing state-of-the-art processes, but to also delivering trained personnel for the new vital sectors of the domestic metals industry. The paper describes the principles that Nickel Group were guided by, as well as the approaches that were used for the development and implementation of state-of-the-art technologies. The members of the Group are also described. The author pays close attention to the historical background. Thus, the author looks at the development of the mineral resources of the Soviet Arctic during the period of the first Five-Year Plans, as well as evacuation and re-evacuation of industry during the 2nd World War. All this helps present the Group’s activity in most challenging conditions of that era and appreciate its role in the Soviet industry of the 1930–1940s.

Ways to reduce technogenic landscape disturbances in mining production

Iron ore mining is followed by significant disturbances of the earth’s surface caused by both iron ore mining facilities (underground mines and open pits) and disposal of mining and concentration wastes on the surface (waste and substandard ore dumps at underground mines, overburden and oxidized rock dumps at open pits, tailings storage facilities at mining and beneficiation plants). In addition, operation of mining enterprises leads to creating hundreds of kilometers of above-ground pipelines, technological roads and railroads; drilling and blasting operations at underground mines and open pits lead to seismic phenomena and geotectonic disturbances of the surface in the form of sinkholes and craters in places of underground workings. The presented scientific work aims to generalize the practice of measures to optimize landscape disturbances caused by mining and develop individual issues of arrangement and technology of reclamation of disturbed surface areas in conditions of Kryvyi Rih iron ore basin. Technogenic surface disturbances accumulated during the period of economic exploitation of the region require a comprehensive solution in two directions. The first one consists in reducing the rate of new destructive impacts on the state of the relief by switching from extensive methods of deposit exploitation to all-round intensification of production (introduction of low-waste technologies, concentration waste re-treatment, oxidized ores processing, transition to technologies of internal dumping). The second one involves optimization of already formed landscape disturbances through reclamation. It is recommended to implement a number of methods of improving individual technogenic landscape formations by engineering and biological methods.

Ecology and utilization of ore dressing tailings

Based on the study of ways to increase the efficiency of metal production through the use of technologies for leaching substandard ores in terms of metal content, a data bank was formed and an algorithm for controlling the processes of leaching substandard non-ferrous ores in terms of metal content was proposed. The concept of the development of technogenic deposits by leaching metals is proposed as an important direction of rational use of subsurface resources. The development of an algorithm for controlling the process of leaching non-ferrous metals from substandard raw materials is a tool for compensating losses of valuable and scarce raw materials allowed in the technological chain. Aspects of the mechanochemical technology of extracting metals to obtain an ecological and economic effect and radical hardening of the mineral and raw material base of mining have been studied.

Prospects for waste-free utilization of ore dressing tailings

The information about the state of the use of natural resources in Russia is given and the need to search for new sources of raw materials for industry is justified. There is a tendency to reduce the production capacity and the rate of extraction of metal ores, which does not allow the use of the infrastructure of mining enterprises and creates the problem of processing substandard ore deposits and disposal of accumulated waste. The concept of deep processing of substandard metal-containing raw materials and a strategy for the survival of mining enterprises, including the use of metal leaching technologies, is formulated. The advantages of technologies with the leaching of metals from mineral raw materials at the stages of its processing are characterized. The advantages of leaching in disintegrators are shown by comparison with the indicators of the basic variant. It is noted that mechanochemical activation improves the quality of concretes made on the basis of recycled tailings. Managing the properties of recyclable materials allows you to implement the principles of resource conservation with an economic effect. It is concluded that the recommended technology is the real direction of technological modification of production.

Application of an improved mining complex for opencast mining of ore deposits

The purpose of the study is reducing the loss of mineral raw materials and increasing the efficiency of mining operations using a mining complex through the introduction of a new design and engineering solution that improves the equipment functionality. The study involves the analysis of known designs of mining equipment capable of providing the transformation of cyclic scooping of rock mass into its continuous loading, as well as screening of fine fractions from the ore mass. High productivity mining complexes are referred to a promising direction of mining equipment development. The article proposes an improved design of the mining complex, which allows to combine the extraction and loading process and ore mass grading. The improved mining complex is equipped with an annular conveyor with vibrating grids through which fines are screened into the accumulation hopper. From the accumulation hopper the small fractions are sent by means of a pneumatic conveying system to the bunker sections of a special-purpose hauler while the oversize product is loaded into a dump truck by a dump conveyor. The fine fractions of substandard ore collected in the bunker sections are sent for heap leaching. The fine fractions of conditioned ore are sent to the concentration plant to be processed. The proposed design and engineering solution employing an improved mining complex will reduce the cost of works and increase the recovery factor of mineral raw materials in the development of complex-structured deposits of ores characterized by natural concentration of small classes. Removal of fine ore fractions directly during the excavation and loading process can significantly reduce the dusting and decrease the loss of mineral raw materials from blowing and spilling of fine fractions.

Радиоэкологическая оценка отложений урановых хвостов (Сумсар, Шекафтар, Терек-Сай)

The article presents the results of radio ecological studies of the territories of uranium tailings in Kyrgyzstan (Sumsar, Shekaftar and Terek-Sai), as well as their current state and assessment of the radioactive contamination’s potential risks. The ore field of this region is characterized as an extremely complex structure and covers about 30 ore occurrences of lead and rare metals. Starting from the Precambrian period both applicative and disjunctive disturbances within its boundaries have been widely developing and being manifested many times throughout the history of geological development. Oxidized and sulfide ores have been developed within the deposit. Unfortunately, serious miscalculations were made. As result of natural disasters; such as earthquakes, landslides, mudflows, etc., several uranium tailing dumbs have been damaged. Day by day, the risk of destruction and the threat of radioactive contamination of the Kyrgyz Republic territory are increasing. There are eight tailing dumps on the territory of Shekaftar uranium natural-technogenic province, the total volume of which is 1194 thousand m3 of radioactive waste. There are 15 mountain dumps of substandard ore with an ore volume of 4585.6 thousand m3 hour, in local areas it exceeds 500 μR/h.

Evaluation of efficiency and environmental safety of leaching metals from ore: ways of development and prospects

The object of research is traditional mining technologies and technical means in combination with underground block leaching (UBL) of metals from rock ores with their preliminary crushing with explosives in installations mounted in mine workings. One of the most problematic areas is the difficulty of achieving a given crushing quality, as well as the required height of ore storage in the chamber for the subsequent leaching of metals and a loosening factor, taking into account the control of the energy of explosive destruction of rock ores. The study used: – data from literary sources and patent documentation in the field of technologies and technical means for UBL of metals from ores in energy disturbed massifs, substantiation of technological parameters of operational blocks; – laboratory and production experiments; – physical modeling of metal extraction from ores from the average linear size of a piece of blasted ore. Analytical studies, comparative analysis of theoretical and practical results using standard and new methods were carried out with the participation of the authors. It was found that the most intensive infiltration leaching occurs when the size class of ore lumps is –100+0 mm. Metals are extracted from fractions –200+100 mm less intensively and for a longer time. To neutralize and flush the spent ore mass, it is recommended to treat it with lime solution and mine water through wells for supplying leaching solutions (irrigation system). The protection of the hydrogeological environment is carried out by silting the bottom of the chamber for collecting productive solutions with clay solution and by constant monitoring of mine water pollution in the zone of UBL influence. On the basis of the positive results obtained from the study and implementation of technologies for UBL of metals from rock ores during the development of block 5–86, in accordance with the recommendations issued, the same approach was used for blocks 5–84–86 and 5–88–90, as well as industrial experimental block 1–75–79. Due to the involvement in the production of substandard ores, the raw material base for the extraction of metals, at the operating mines, can be increased by 1.4–1.6 times. The research results can be used in underground mining of ore deposits of complex structure in Ukraine, the Russian Federation, the Republic of Kazakhstan and other developed mining countries of the world.

On the concept of in-situ metal leaching

The information on history of in-situ metal leaching method (ISL) was given. The role of Russian scientists and research organizations in research into ISL processes was shown. Examples of ISL application at the mines of the USSR, the CIS and nonCIS countries with the implementation features were given. The main disadvantages of ISL were formulated: low rate of metal production and difficulty in monitoring the completeness of metal recovery into pregnant solution. It was noted that underground leaching of even well-crushed ores lasts for many years. This, under otherwise equal conditions, decreases attractiveness of ISL in comparison with traditional methods of metal mining. Well-known and new promising methods of the leaching process intensification for increasing the rate of metal extraction into solution were described. As illustrated by the North Caucasian deposits of the Sadon group, the expediency of ISL use for extracting the residual reserves, which would not be extracted by the traditional methods, was shown. The role of Professor I.A. Ostroushko in development and implementation of methods for extracting metals remained in the mined-out space of mines, in particular, by extracting metals from the Sadon deposits wastewater. Information on the current state of ISL application was given. The conclusion was made about insufficient use of this promising method in mining in some regions. For the first time, the details of the ISL general concept were clarified: the feasibility of ISL use not only in favorable conditions, but also at non-continuous geology and mineralization; ISL applicability for not only substandard ores (non-extractable by traditional mining methods), but also for balance reserves; ISL (block leaching) was proposed as an alternative to traditional mining methods in specific conditions, for example, at the North Caucasian complex ore deposits.

Prospects for development of Sadon deposits by in-situ leaching

The information on history of in-situ metal leaching method (ISL) was given. The role of Russian scientists and research organizations in research into ISL processes was shown. Examples of ISL application at the mines of the USSR, the CIS and non-CIS countries with the implementation features were given. The main disadvantages of ISL were formulated: low rate of metal production and difficulty in monitoring the completeness of metal recovery into pregnant solution. It was noted that underground leaching of even well-crushed ores lasts for many years. This, under otherwise equal conditions, decreases attractiveness of ISL in comparison with traditional methods of metal mining. Well-known and new promising methods of the leaching process intensification for increasing the rate of metal extraction into solution were described. As illustrated by the North Caucasian deposits of the Sadon group, the expediency of ISL use for extracting the residual reserves, which would not be extracted by the traditional methods, was shown. The role of Professor I. A. Ostroushko in development and implementation of methods for extracting metals remained in the mined-out space of mines, in particular, by extracting metals from the Sadon deposits wastewater. Information on the current state of ISL application was given. The conclusion was made about insufficient use of this promising method in mining in some regions. For the first time, the details of the ISL general concept were clarified: the feasibility of ISL use not only in favorable conditions, but also at non-continuous geology and mineralization; ISL applicability for not only substandard ores (non-extractable by traditional mining methods), but also for balance reserves; ISL (block leaching) was proposed as an alternative to traditional mining methods in specific conditions, for example, at the North Caucasian complex ore deposits.

ЗАВИСИМОСТЬ КАЧЕСТВЕННО-КОЛИЧЕСТВЕННЫХ ПОКАЗАТЕЛЕЙ ЗАПАСОВ РУДЫ ОТ МАКСИМАЛЬНО ДОПУСТИМОГО ИНТЕРВАЛА НЕКОНДИЦИОННЫХ РУД НА СОТКСКОМ ЗОЛОТОРУДНОМ МЕСТОРОЖДЕНИИ

At the Sotk gold ore deposit, the following morphological types of ore bodies can be distinguished: vein zones; veins and vein-like bodies; mineralized dykes and a vein zone in gabbro - massifs. The deposit is characterized by rather difficult mining and technical conditions. The enclosing rocks of the near-ore bodies have undergone intense hydrothermal changes at a distance of 5,0...10,0 m to 50,0 m, as a result of which, within the boundaries of these zones, the enclosing rocks have lost their strength and stability. The stability of the host rocks is also greatly influenced by postore tectonic faults, which are widespread in the field. The ore is also volatile. The strength factor of ore and host rocks varies from 3 to 20, with a predominance of 8...13. Hydrothermally altered metasomatites, which make up the mineralized zones, are prone to caking. The ore loosening factor is 1,25...1,40. The average bulk density of ore is 2,6 t / m3, and the bulk density of the host rocks is 2,3... 3,2 t / m3. At the deposit, conditioned and substandard intervals alternate with each other and there is no clearly expressed regularity of their spatial location, which predetermines the use of the ore-bearing factor when calculating ore reserves. The ore content ratio is determined by the ratio of the amount of conditioned ores to the total amount of ore mass, and the amount of conditioned ores is determined using the condition parameter “maximum - allowable range of substandard ores or waste rocks” included in the reserve calculation. For the Sotk gold ore deposit, the regularities of changes in ore reserves in the subsoil, the gold content in the ore massif and the ore content factor from the “maximum allowable to an increase in ore reserves in the subsoil and the ore content ratio with a decrease in the gold content in the ore massif and vice versa are revealed.

К диверсификации рудодобывающего комплекса как направления развития экономической системы депрессивного типа

The priorities for the development of the industrial complex are to compensate for market risks by dispersing activities into several types of business with the development of new products, the cost of which is reduced due to the use of the existing infrastructure. The prospects of mining enterprises of the North Caucasus in the implementation of production diversification are outlined. The results of substantiating the effectiveness of diversification at various volumes of ore mining in the conditions of the unprofitable Sadonsky lead-zinc plant with a graphical interpretation of economic calculations are given. The results of calculating the efficiency of involving substandard technogenic ores in the development, obtained by comparing alternative options that differ in the size of reserves, are given. An equation for the balance of values is proposed, which establishes the relationship between the volume of production and the completeness of extraction of reserves of deposits during the development of reserves of substandard ores and wastes. To assess the effectiveness of actions during diversification, an integral indicator of flexibility is proposed and the method of marginal analysis is used to reduce the uncertainty of situations. A graph of the relationship between the volume of ore production, economic indicators and the break-even point is shown. Okha-characterized the mineral resource base of diversified enterprises and diversification products for consumption by related industries. It is shown that the diversification of the ore mining complex is still a little used reserve for the development of the economic system of the depressive type.

Prospects for the use of peat in metallurgy

A large number of metallurgical industry enterprises in the regions of Russia mainly use imported and rather expensive coking coal or natural gas for steelmaking. However, almost all regions of Russia have large reserves of peat, which can replace expensive hydrocarbon raw materials in metallurgical processes. For this reason, the use of peat raw materials (briquette, piece) in metallurgy is of scientific and practical interest. The properties of peat briquettes and pellets in the process of pyrometallurgical processing are set by the methods and technological parameters of their preparation. The article presents the results of a study of the influence of the type and quality properties of peat on the technological process of recovering peat compositions prepared on the basis of iron ore from the Bakchinsky deposit. Peat of the Vasyugan peat massif was used for the production of peat melting compositions. Experimental data showed that, for peat compositions, low-ash peat on the watershed is suitable. The use of peat melting compositions allows us to solve the problem of the return of ore dust and substandard ore in the smelting processes and thereby develop a rational low-waste technology.

Friendly and Resource-Saving Methods of Underground Ore Mining in Disturbed Rock Masses

One of the most problematic aspects in underground ore extraction in mining-disturbed rock masses is backfilling of man-made voids, which affect origination and redistribution of stress-strain state of the rock mass. Their existence in the earth's crust provokes subsidence/collapse of the day surface and also contributes to arising geomechanical and seismic phenomena. The purpose of the study is to substantiate environmental-friendly and resource-saving methods for backfilling of voids in underground ore mining based on revealing the features of rock integrity of the day surface and life-sustaining activity of the population living in the mining-affected area. The main negative consequences of the impact of mining on the environment and humans are high costs for conserving day surface and ensuring life-sustaining activity of the population living in the mining-affected area, as well as removing large areas of land from human activity, etc. Based on the study of a rock mass stress-strain state using geophysical and surveying methods, an environment-friendly method for backfilling of man-made voids in disturbed rock masses is proposed. It enables ensuring the integrity of the day surface and life-sustaining activity of the population living in the mining-affected area (in the vicinity of mines, dumps, sites of backfilling complexes, preconcentration and heap leaching of metals from substandard ores, tailings storage facilities, etc.). Combined geotechnologies are proposed for backfilling of voids during the development of ore deposits by underground block leaching, and scientific and methodological and technical support was provided for drilling and blasting preparation of hard ores and underground leaching of pilot blocks at the Michurinsky deposit of GP VostGOK, Ukraine. The research findings can be used in underground mining of ore deposits of complicated structure.