Tailings Utilization and Zinc Extraction Based on Mechanochemical Activation

The significant containment of the global mining industry is caused by the problem of the transition to sustainable metal extraction and the integrated use of technogenic raw materials from the tailings of ore processing. The modeling of metal leaching processes using mechanical activation of polymetallic raw material components is particularly important in expanding the application of mining tailings as inert fillers of filling mixtures. This study is aimed at detecting the rotor speed factor on the chemical and mechanochemical effect of zinc yield growth from polymetallic tailings of the mining industry. In this regard, the purpose of this study was to improve the modeling of metal leaching processes using mechanical activation by improving the compositions of the filling mixtures. The methodology of the work included several comprehensive studies: the mechanical activation of tailings during zinc leaching from pulp in the DESI-11 disintegrator; the activation of enrichment tailings and the formation of a filling mass with different parameters of the component composition; the curing of cubic samples and their testing on the IP-1250 press. The Vi Improved text editor was used to prepare the algorithms for deterministic methods of three-dimensional interpolation in the Python language. The experimental results were graphically displayed using Gnuplot. The study of the agitation leaching of the waste obtained from the Sadonskiy mining district results in the fact that the NaCl mass concentration decreased from 13 to 1% and the H2SO4 concentration stabilization within 0.5 to 0.6% led to a 3-time increase in the zinc yield from the pulp, according to the polynomial law (from 28 to 91%). The obtained results expand the idea of the mechanism of the strength gain by the filling mass under mechanical activation on the components of the filling mixture, as well as changes in the efficiency of zinc leaching at different ratios of two types of lixiviants (sulphuric acid and sodium chloride) in the leaching solution

Goaf filling with isolation preserving earth surface

The relevance of the work is caused by the need to combine the principles of economic efficiency of array state control while filling the cavities formed when mining and safety of the environment in the area of mineral resource extraction with the increase in volumes of extraction of mineral raw materials for the needs of the growing population. The aim of the research is to develop the parameters of ore extraction technique without filling the cavities with the material. These materials would preserve the earth surface from destruction in the case of rock caving zone yield to the level of pumps for indefinitely long period of time after filling the workings. Research methods: critical analysis of the experience in development of deposits similar in ore localization conditions, physical and mathematical modelling of the production technologies and forecasting the ways of development of technology, experimental determination of the value of a span limited in stability condition. Results. It is shown that the earth surface stability over the filled deposit area after its performance is provided with preventing the possibility of deformation phenomena occurrence. It is proved that the field with the void volume of 2 million m3 can be repaid without filling voids with backfill material. The authors have substantiated the necessity of a more complete accounting of geomechanical factors in assessment of environmental and economic efficiency of extraction of mineral raw materials. The paper introduces the model of estimation of underground mining efficiency depending on the use of properties of ore-bearing massifs. Conclusions. Purposeful use of the properties of ore-bearing massifs largely determines the performance indicators of underground mining. One of the main operational issues is the choice of development options to ensure the safety of the earth surface

Conditions of leaching non-ferrous metals from non-commercial reserves

The relevance. Traditional technologies of underground development of ore deposits are characterized by irretrievable losses of non-commercial reserves in the ground. The alternative to traditional technologies is the technology of metals leaching in underground conditions without extracting the earth's surface, allowing production of non-commercial reserves. The aim of the study is to prove technical and economic feasibility of leaching metals from sub-standard metal-bearing minerals while solving the problems related to this. Method of the study problem is based on the analysis of the results of the industrial-experimental leaching non-commercial ores, and commercial ones on rocky fields with the investigation of metal extraction in product solution due to the technological exposure of a re+ agent solution on metal ores. Results. The authors have proposed the algorithm of combining the alternative technologies of underground mining with the development of a compensation space for crushing non-commercial ores by excavating commercial ones; justified the principle of combining the technologies of mine treatment in traditional way and underground one with selective extraction of a part of commercial ores and formation of the compensation space required for fragmentation, where the non-commercial ore is removed with further leaching. The paper introduces the detailed understanding of the main processes of a new technology: blasting, draw, irrigation and intensification of leaching, and demonstrates the benefits of engaging non-commercial ores in manufacture by a new technology, including the utilization of mineral resources, strengthening the resource base, reducing the burden on the environment. Conclusions. Combination of technologies which allows extracting a part of commercial ores for factory processing and averaging the content of non-commercial ores to the acceptable value within leaching, meets the interests of resource and nature preservation and it is a promising direction of strengthening the raw material base of mining industry, revitalizing the economy and addressing the environ-mental and social problems

THE STRENGTH OF ROCK STRUCTURES IN UNDERGROUND MINING

Questions of the mechanics of rock massif with use resulting in destroyed rocks structures with dynamically occurring in the underground workings of the processes are considered. The ability of natural and technologically disturbed species to maintain stable structure during the interaction in the array is gravity-tectonic-structural field is investigated. The model definition elements of the control array is given. It is shown that the rock supporting structure within the covered portions of the crust allows the use of a minimized the cost of labor and materials and construction elements of underground Geotechnolog

Possibility justification of losses reduction in pillars by backwatering with hardening mixtures

The relevance of the research. The problem of mining field development quality is aggravating in new economic management conditions. The need to preserve the earth's surface, reduce ore losses and amount of diluting rocks can be ensured by filling out the space with hardening mixtures. This opportunity is limited by high-value components of hardening mixtures, which can be reduced by using mining waste. The desired effect is achieved by a rational use of properties of natural and man-made arrays. Objectives of the study: to justify the possibility of losses reduction in interchamber pillars while regulating the stress in the array by means of ore pillars backwater with hardening mixtures. The objective is achieved by resolving a problem of geomechanical stress estimation in the array depending on the mining and use of hardening mixtures mechanism for stress regulation. Methods used in the research. The stress state of the array in various phases of its weakening by sewage treatment works is studied with a photoelastic method on the models of optically active polyurethane with a variable coefficient of lateral thrust while maintaining the rest of the model parameters. The results. The authors found that when the stress level is maintained ore pillar losses can be reduced by decreasing the size of pillars by an amount depending on the amount of developed space, physical and mechanical properties of ores and strength of hardening mixtures. Backwater with hardening mixtures reduces the stress level in the vicinity of the stopes by a certain value that comprehensively improves the economic and environmental performance of underground mining, reducing losses in the interior of the earth

Feasibility of leaching poor ore in a pile

Relevance. Traditional beneficiation processes do not provide full disclosure of minerals due to the design parameters of the equipment, so they are modernized by attracting operations of hydrometallurgical and chemical processing, which increase the efficiency of enrichment due to application of a new kind of energy, for example, technology of chemical leaching of metals. The direction of increasing the volume of production of metals by leaching non-conforming raw materials and wastes of mining and processing in piles, which is used to produce copper, gold, uranium, becomes more relevant. The aim of the study is the proof of ecological-economic efficiency of leaching of non-conforming raw materials and wastes of mining and processing in a pile and substantiation of their prospects. Methods of the research include analysis and synthesis of results of previously performed theoretical and experimental studies and those borrowed from the literature, patent data in analysis modeling. Results. In the complex «hydrometallurgy and ore leaching» the least cost of the product is achieved when the uranium content in ore is 0,08 %. At increasing uranium content without growth in ore production output the rate of production decreases due to low recoveries of uranium and duration of leaching. Calculation of irrigation parameters is based on the laws of infiltration hydrodynamics and correlations between the solvent, its concentration and wetting zone diameter. Analytical modeling of leaching efficiency was implemented in designing low-grade ores processing in a specific field. The distinctive feature of the project is in cascade location of the equipment for gravity movement of the material. The processes are arranged according to the principle of maximum reduction of process pumping, trails of technological pipelines and other utilities. The practice of dumping leaching tailings contributes to development of waste natural leaching with migration of liquid chemical components in crust layers and gas ones - into atmosphere, that decreases uranium leaching rates in a pile, reducing it to the level of work in progress with the complexity of possibilities of deep disposal. Conclusions. After leaching in a pile, uranium content in leaching tailings remains high enough to be considered as poor ore with radiation impact on the environment. A promising direction for wasteless recovery of metals from sub-standard materials is a combination of chemical processing and mechanical activation in leaching

Possibility justification of losses reduction in pillars by backwatering with hardening mixtures

The relevance of the research. The problem of mining field development quality is aggravating in new economic management conditions. The need to preserve the earth's surface, reduce ore losses and amount of diluting rocks can be ensured by filling out the space with hardening mixtures. This opportunity is limited by high-value components of hardening mixtures, which can be reduced by using mining waste. The desired effect is achieved by a rational use of properties of natural and man-made arrays. Objectives of the study: to justify the possibility of losses reduction in interchamber pillars while regulating the stress in the array by means of ore pillars backwater with hardening mixtures. The objective is achieved by resolving a problem of geomechanical stress estimation in the array depending on the mining and use of hardening mixtures mechanism for stress regulation. Methods used in the research. The stress state of the array in various phases of its weakening by sewage treatment works is studied with a photoelastic method on the models of optically active polyurethane with a variable coefficient of lateral thrust while maintaining the rest of the model parameters. The results. The authors found that when the stress level is maintained ore pillar losses can be reduced by decreasing the size of pillars by an amount depending on the amount of developed space, physical and mechanical properties of ores and strength of hardening mixtures. Backwater with hardening mixtures reduces the stress level in the vicinity of the stopes by a certain value that comprehensively improves the economic and environmental performance of underground mining, reducing losses in the interior of the earth

Optimization of filling mixture strength considering rock intensity

The relevance of the research is caused by the tendency to reduce the cost of managing the state of water-bearing rocks in underground mining of metal deposits of rock type. The aim of the research is to study the technical possibilities of minimizing strength of hardening filling mixtures while ensuring the safety of operations and maintain the quality of ore mined by taking into account the actual stresses. Methods: a review of theory and practice, using the results of field studies carried out with the involvement of material publications, simulation of the results of technological and economic research, summarizing the results of the study. Results. The authors have systematized the information on interaction of natural stress fields and the stress arising from man-made intervention in underground mining with laying voids with hardening mixtures. It is noted that the practice of ore deposits exploration proved the absence of satisfactory adjustment between the design parameters and actual strength, their discrepancy to geostatic distribution law. The authors proposed the model of relationship between quality ore production figures and the state of rock arrays by the strength of geomechanical system elements. The paper introduces the results of field studies of a powerful deposit array stress state, confirming and explaining the irregular stress distribution. Conclusions. Mountain massif and the rocks composing it are heterogeneous and stress in their elements may be determined adequately only instrumentally. The actual voltage can differ from the calculated values, being affected by geological faults of the crust. Differentiation of the filling mixture composition allows reducing the consumption of cement for their preparation taking into account the real state of the array. This improves the technical and economic indicators of technique while maintaining a safe conditions of ore production

On the issue of conversion of metal deposit development techniques

The relevance of providing industry with metals for supplying the needs of population increases in radical changes in the economic system and continuous deterioration of conditions for exploring mineral deposits using the underground method. The aim of the research is to substantiate the appropriateness of organizational-economic and production-technological measures to convert mining industry to innovative techniques in mineral deposits exploration by the underground method. Research methods include the analysis of international experience and literature, obtaining and processing data based on multiple regression and correlation analysis, pilot plant testing of alternative technologies. Results. It was ascertained that the directions of mining industry conversion include application of solid mixtures for laying-out space and leaching of metals from ores. It is shown that the environmental concept of technological upgrading consists in transferring the processing of the main volume of ores into underground conditions; the efficiency of utilization of tailings consists in reducing the level of damage from tailings, the value of metals and non-metals obtained in processing, raw materials for construction industry and associated commercial products. The feasibility of development of conversion technologies is determined by the ratio of the compensation of costs and damages from waste storage, production capacity of the disposal enterprise and its technological level. Diversification of mining production to underground mining of deposits in near-term perspective requires the correction in engineering support of mining on mountain specialties. Production activities of mining engineers is related to the efficient use of resources, therefore, a mining engineer should be a technologist and processor, hydrogeologist, ecologist, etc. Conversion of technologies is implemented, provided that: the efficiency of ore extraction is based on the value of recoverable and not recoverable metals, and taking into account the effective quantity of damage to the environment. Conclusions: restoration of mining industry potential depends on implementation of innovative technologies, provided adequate engineers of the new generation

Faux ceiling at underground mining as an alternative to ore pillar

Relevance of the research is caused by the necessity to minimize ore losses in pillars, left for different purposes, for meeting a steadily increasing demand for raw materials to produce metals when ore field development conditions deteriorate. The aim of the research is to study the feasibility and economic viability of using strength and function differentiated faux concrete ceiling instead of ore pillars. Methods: analysis of theoretical heritage of Russian and foreign geomechanical schools, advanced experience in developing complex fields and design studies based on the theory of a plate clamped rigidly with maximum load in the bearings and hinges. The paper describes the possibility of combining ceiling construction design and technologies: solid carrier ceiling and «lite» ceiling conjugated to the latter over the rest part of the block by the example of the Northern Kazakhstan field development by the system of axes sublevel within the structurally inhomogeneous rock mass; hardening the left in store ore by feeding hardening mixture to it for obtaining economic benefits. Results. The authors have proposed the variants of faux ceiling based on hardening concrete mixtures, taking into account the mechanism of rock pressure in the developed areas of the ore field. It is proved that the faux ceiling can compete with the ore pillars, especially at development of valuable metal ores. Conclusions. When developing the valuable ore reserves in geologically disturbed and disintegrated arrays the construction of faux ceiling, as an alternative to ore pillars, is a way to reduce the risk of mining operations and improve the quality of the extracted ore. This is the reserve of economic recovery in current mining