The article introduces the main scientific and practical results of the development of geoenergetic fundamentals for the underground mining of ore deposits by means of disclosing physical essence of the phenomenon of zonal encapsulation of mine workings. The phenomena, processes and regularities of mine workings encapsulation by an array with the definition of shape, size, number of energy zones, sinusoidal-damped stresses, and annular deformation areas are systematized. An energy theory of the study of the parameters of zonal encapsulation of mine workings has been developed: the shape, size, quantity and conditions for the formation of energy zones and the boundaries of possible destruction of the massif. Power-law dependences of the change in the dimensions of adjacent energy bands are established, the ratio of which is constant from the size and shape, the depth of deposition and the physical properties of the array enclosing the working. The thermodynamic theory of studying the state of the rock massif undisturbed by the excavations has been improved by taking into account the processes of redistribution of geoenergy flows and entropy exchange in an undisturbed massif with the isolation into a separate research method – entropy. The sinusoidal-damped dependence of the autowave oscillations of stresses in the massif disturbed by the workings on the gradients of density, temperature, gas and water saturation of rocks has been specified. Geoenergetic approaches to the selection of traces of preparatory workings, calculation of the parameters of their fastening are recommended. The parameters of performing stoping in energy zones of safety capsules are justified. The estimation of efficiency of geoenergetic technologies and realization of industrial introduction at underground development of ore deposits is introduced.
The article is devoted to the problem of reducing the dilution of metal ore by overlapping and enclosing rock in the production process in underground mining. Some information is given about the state of knowledge of production quality management processes under the development systems with a collapse of ore under the overlapping rocks. Development results are introduced of a complex field structure under a flexible tree-rope and steel cable overlappings. The practice in the application of overlappings of different structures depending on the conditions of development in the uranium-mining industry is described. Overlappings strength determination methods are systematized and typified. For the conditions of polymetallic deposit, economic-mathematical comparison of alternatives with the collapse of the core technology and under the overlapping is fulfilled. The problem of improving the quality indicators of the produced ore are formulated through the separation of ore and rock by the overlappings, including the substantiation of the separation efficiency, optimization of overlappings design for each type differentially, the release of lost ore under the overlappings effectiveness determination, and overlappings structure development. The article systematizes the engineering methods of reducing dilution magnitude with the release of the previously lost ore which are applied in ore mining, also by means of load-bearing and separating overlappings application. It is predicted that the prospects of the direction include bridges cost-cutting through the development of new composite materials. It is shown that improving the quality of previously lost produced ore and ore extracted with overlappings is an essential element of expanding raw-mineral base and mining enterprises economic rehabilitation. The results of the study are of interest to some existing mining enterprises and some mining enterprises under construction.
Main scientific and practical results of hardening stowage mixture components activation efficiency improvement in vibration pipeline transport plants for worked out area filling are introduced on the basis of new technologies and hardware, which can reduce transportation energy consumption down to 0.25–0.30 kW/h on 1 m3 of mixture, increase the length of pipeline section up to 150–200 m, capacity – 1.8–2.0 times, artificial massif strength – in 20–25%, provide reliable mixtures delivery, standard cone settling of which constitutes 10–13 cm, which contain by mass 0.10–0.35 dispersed particles and solid concentration 0,80–0,85 for distance which exceeds vertical flight height in 20 times, and total mixture removal out of the pipeline under water discharge 3–5 m3 for one sluice. The ratio of flexible supports rigidity is obtained in horizontal and vertical surfaces, equal to 1.2–1.4, under which the most efficient trajectory of pipeline motion is obtained under circular exciting force of a vibration generator. The efficiency of elliptical vibrations of a pipeline impact on the reduction of hardening stowage mixture motion resistance is shown.
The article is dedicated to rational schemes of developing ore deposits at large deposits with complex structure for underground mining with the improvement of output ore quality and workplace safety. Critical analysis of patent literature over the use of development schemes at deposits with the same conditions is fulfilled, together with physical modeling of broken ore output conditions at equivalent materials. Complex criterion is formulated to estimate the variants of reserves preparation for stoping with inclined descents, the essence of which reduces to representative and objective estimation of required scope of development mining operations in providing required speed of mining depth increase, capacity of mobile drilling and haulage equipment within a shift, regular aeration of stoping faces, and labour efficiency. Quantitative assessment of level development variants is fulfilled with the optimization of distance between workings and the account of support pressure at the stages of works development. Quantitative results of modeling broken ore output parameters dependencies are introduced. For the conditions in question, optimal variants of development with inclined descents with varied location towards ore deposits are recommended.
The purpose of the given work is to substantiate the possibilities of strengthening the potential of depressed mining enterprises during metals underground mining by the example of the North Caucasian region. The methodology of the given work synthesizes theory and practice of the use of technologies, experiments on metals leaching, and economic estimation of technologies efficiency by means of comparing mineral recovery rate factor using alternative techniques. The article substantiates the priority of combining technologies of poor ores leaching and traditional technologies of rich ore mining. The analysis is fulfilled of mixed technologies application underground mine for commercial ore production, which is the first of a kind in the world practice. The basis for combining traditional and new technologies of ore recovery is examined by means of combining technologies within the limits of a single process. The model of identifying ecological and economic efficiency of deposits exploitation is suggested; the account of the recovered resources completeness lies at the heart of the model. The article introduces the example of determining recurrent extraction ratio when using mixed technologies. Results field of application includes formerly subsidized mining enterprises, which develop metal ore deposits using underground method. Revitalization of profitable metal production at depressed mining enterprises is possible on the basis of traditional and new leaching technologies combination.
The article shows basic scientific and practice results for the development and introduction of innovation techniques of complex structure deposits underground mining, effectiveness increase of their development due to the application of room system with consolidation stowing and block underground leaching of uranium out of rock ores. The validity of ore dressing scheme is confirmed (maximum deviation of actually measured class –25+0 is 7,2 %). It is determined, that the most intense percolation leaching happens under the grain-size class of ore fractions –100+0 mm. For the conditions of Michurin mineral deposit (the Ukraine), by condition of leaching, the output of this fraction at the broken ore is recommended over 90 %. Less strongly and more protractedly metals are extracted out of the fractions –200+100 mm. It is determined, that the breaking of ores with the help of deep-hole charges with the diameter 0,085 and 0,105 m is characterized by almost the same fineness ratio as 0,067 m wells diameter, however under the smaller specific consumption of explosives. Transfer to drilling over the rock ore with the wells of 0,085 m diameter is recommended.
The parameters of stable equivalent spans of horizontal exposures in chambers at working of deposits with a complex structure in the depth ranging from 45 to 220 m to the earth's surface, which vary from 13 to 15 m are rationalized. In addition, the safety factor is in inverse power-law dependence from the number of sound impulses of destruction and takes into account the reliability of the steady state of the ceiling equal to 0.9831 at the time of its existence up to 8 months, which dictates the performance of the operating units. Based on the results of complex research, development and production activities, the following relationship were set: changes in safety factor on the probability of destruction of a pillar of the ceiling, and the maximum allowable probability of destruction of its exposure at steady and limit states; forecast the stability of structural elements of chamber systems of development and ore massifs by the volume of margin of safety, which increases the safety of mining operations and the effectiveness of development of the deposit.