The technogenic impact of mining on the environment is analyzed and the transition to geotechnology with stowing to reduce the impact of mining operations is proposed. The results of the research work devoted to the justification of parameters of the development of salt deposits with stowing and the definition of the influence of stowing on the dynamics of deformation of the underworked rock massif are presented. The relevance of research aimed at creating a safe and efficient technology for the transition from systems with natural maintenance of stoping space to systems with stowing has been substantiated. The results of studies on qualitative and quantitative assessment of the state of the rock massif (by the finite element method using FLAC3D software), worked out by combines, are given and the dynamics of the impact of mining operations on the rock mass and the change in the maximum stresses during the hardening of the stowing in the chambers are revealed. The numerical modeling method is used to analyze the conditions of change in the state of the underworked rock mass, to establish the mechanisms of its deformation at various stages of development. It is recommended to use this approach for geotechnical assessment of the rock mass state in conditions of using development systems of different classes.
The paper analyzes losses during the development of low-value water-soluble ore deposits. The importance of development systems with backfill is shown. The use of industrial wastes of water-soluble ores to replace specially produced inert components in the preparation of backfill seems to be a good way to utilize them. The aim of the work was to create a fill mass with improved strength properties based on industrial wastes of water-soluble ores activated with a nanomodifying material. The characteristics (chemical and granulometric compositions) of an aggregate of the backfill based on the waste from enrichment of water-soluble ores are given. The validation of the hardening mixture compositions for various mining systems was carried out considering: the specified strength, the time of the artificial mass erection, the time to achieve the required strength properties of the material, which determine the possible intensity of the mining operations; method of transporting the backfill. The expediency of using a multilayer fulleroid nanomodifier astralene as a nanomodifying additive has been proved. The effect of the backfill activation with a nanomodifying additive, astralene, on the structural changes of halite wastes from the halurgic enrichment of water-soluble ores (potash) was investigated. To study the strength properties of the fill mass, the comparative analytical method was used. The strength properties of the backfill were measured in standard test periods, taking into account the intensity of hardening of the backfill material (after 7, 14, 28, 60, 90 days). To obtain reliable results, 10 backfill samples were tested at each of the scheduled dates. The shape and chemical composition of crystalline new forms were studied. Studies were performed using X-ray phase analysis and scanning electron microscopy. As a result of uniaxial compression of hardening backfill samples, the dependence of the ultimate strength on the astralene content and the hardening time were established. It has been experimentally proved that the use of a nanomodifying additive, astralene, in the backfill allows an increase in the strength properties of the created artificial mass by 1.76–2.36 times while reducing binder consumption.
The article addresses the issue of mining and industrial waste stored in tailings and heaps in mining areas, and it explores the existing, as well as new, ways of reducing its harmful impact on the environment. On the basis of the Russian experience in mining industry in Ural, it presents a process which makes it possible to eliminate the amassed hazardous waste, retrieve the valuable material (metals) stored in it, and use the remaining waste as backfill in order to both: store it underground (and not on the surface) and prevent the disasters caused by the collapse of the abandoned shafts, thus prolonging the functioning of the mining areas. The process includes preliminary activation treatment of materials found in industrial waste in a disintegrator to protect the environment from toxic pollution. The promising results of the experiment have been discussed, taking into account the complexities of economic evaluation of the idea.
In this paper, a method of mathematical modeling for solving the problem of reusing man-made waste from mining and the processing of ores is proposed. The use of intermediate products (man-made waste: tailings of processing plants, rocks from sinking operations and the technical water of mine drainage) in cyclic production presupposes their use as fill material components and placement in the mined-out voids of underground mines. The influence of mining factors on the fill material composition and the parameters of the created fill mass is justified. The results of a practical implementation of the proposed mathematical model are presented, and an algorithm is compiled. Deformation changes and stress concentration are key criteria in the proposed mathematical model. The proposed algorithm allows for the determination of the preferred system of deposit development, and the selection of its parameters and the fill material composition.
Humanity development is associated with higher spiritual and social behaviour and financial shape, which is an undeniable factor of urbanisation. Previously, in areas of georesource concentration, cities and settlements were formed with people exploiting these georesources. However, imperfect technologies lead to rapid depletion of reserves and industrial and environmental disasters, which affect the vulnerability of cities and the people living in them. The analysis of applied technologies has demonstrated that potash extraction is accompanied by a low recovery ratio, high mine accidents, and environmental problems. The principles of sustainable development of geo-resources for the creation of mining technologies that ensure industrial safety, environmental sustainability, and extending the life of the mining enterprise to save working places will reduce the vulnerability of cities. This article proposes the use of the room-and-pillar mining method with the replacement of natural supports with artificial ones. Three-stage stoping with backfill is considered. Numerical modelling has shown stabilisation of mining and geomechanical processes, which confirms the prospectivity of the method with backfill. For these purposes, this research presents a new backfill composition based on local industrial waste. Schemes of backfill preparation and feeding into the mined-out space are proposed. The proposed technology, based on the principles of sustainable development of georesources, is the foundation for an economically profitable, environmentally friendly, and socially responsible mining enterprise. The implementation of the principles of sustainable development of georesources will allow for the preservation of cities and reduce their vulnerability.
The results of the scientific and research work devoted to modeling the stress-strain state of the mining system of an underground mine using the finite element method in the FLAC3D software are presented in the article. The possibility of using room-and-pillar mining with backfill with the abandonment of chain pillars is justified. The results are presented concerning the research results of the quantitative assessment of the mass using the von Mises equation and Norton' power law of creep to estimate the contour stress. It becomes possible to determine the sequence of mining of the deposit area and the stage-by-stage filling of the stopes at the stage of mining design due to the high accuracy of modeling the stress-strain state of the mass near mining operations using FLAC3D software. The proposed approach is possible when evaluating the geotechnical state of the rock mass when using the mining systems with various methods of support of the mined-out area: natural; artificial; with the collapse of ores and enclosing rocks, as well as when calculating the combined method of deposit development. A differentiated approach to assessing the state of the mass is possible considering difficult mining and geological conditions, conditions of increased rock pressure, abundant water influx, increased fracturing of rocks by introducing additional conditions into the model depending on its geotechnical state. Variant of the comprehensive exploitation of mineral resources was proposed considering the total value of natural and man-made geo-resources of the area being mined. The possibility of rational use of the mined-out space with the use of various positive qualities of geo-resources at their manmade transformation is also considered. An assessment of the mineral and raw materials potential of the mined area is given with a proposal for the prospects of increasing the integrated approach of excavation, increasing the life of the mining enterprise and the complexity of developing this area.