The necessity for the increase in the volume of ore production to satisfy the needs for raw minerals and complication of the conditions of ore deposits development make the search for hardening stowage mixtures production reserves actual, also by means of applying technologies, which change the technological properties of mixtures ingredients. Experiments in the search of efficient technologies of hardening mixtures components activation are aimed at providing the production with cheap and available raw material. The article introduces the results of the first international experimental exploitation of the technology of combined activation of hardening mixtures on an industrial scale in the process of developing metal ore deposit. The flowsheet of a plant for the realization of a new technology is recommended. It has been shown, that the efficiency of hardening mixtures preparation and transportation isn’t merely determined by the interaction of well-known factors, but also by the superposition of the factor of activation. It has been determined that the combination of the methods of the mixtures ingredients activation possesses a range of advantages: possibility to enlarge the raw materials base, the increase of subsoil resources fullness ratio, the possibility to deliver the mixture over a distance, exceeding the critical distance for traditional technologies, which makes it possible to abandon the construction of new stowage facilities. The technologies of stowing with hardening mixtures provide the safety of mining, maximum completeness of utilization, subsoil and environmental protection. Reduction in the cost of mixtures is achieved with the activators application. The use of the desintegration technology provides the increase in the activity of binders.
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.
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 article examines efficiency improvement of dust collection at iron ore processing on the basis of development and introduction of electrical cleaning of aspiration emissions from iron-ore processing plants. It will help collecting dust with various electrical resistance, improve environmental control and working conditions, and reduce effective goods loss. Dust settling at internal electrode helps selecting 10–15% of flow with high dust concentration and direct it to the bunker, where coagulation and settling occur. The model of a two-stage electrofilter with dust settling on an internal electrode of a small diameter (26–30 mm) is worked out for air cleaning from aerosols containing particles with various specific electrical conduction. The article examines the processes of dust charging and settling at the developed electrofilter, electrode dimensions are determined, discharge rollers quantity of raws, operating voltage and speed of cleaned flow, required to calculate the filter of the given construction. Dust collection efficiency is experimentally determined, which at average constitutes 0.89 from the computed value, which is explained by the carry over of the part of dust owing to its reloading at settling electrode at the part where there is no corona discharge.
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.
The article provides the main results of the rationale for the seismic safe parameters of explosions in underground mining of the near-surface deposit reserves under urban development using chamber system of mining with a hardening filling with the preservation of residential development and the social factors. Methods of rationale for the coefficient of attenuation of seismic vibrations from the charge to the protected object, as well as the coefficient of proportionality characterizing the environment conducting seismic vibrations are described. It is shown that the efficiency of the screening effect of worked-out area of a chamber is determined by the coefficient of the screening adaptation, which is numerically equal to the ratio of the observed speed of fluctuations in the diffracted wave to the speed in the direct wave. The maximum value of the coefficient of screening of the worked-out area of the chamber on the speed of displacement of the mass by the experimental data did not exceed 0.47.
The main scientific and practical results of research and development of innovative technologies for waste management in uranium production on the basis of their use to fill out spaces and maps of surface tailings in immobilization (curing) as developed by experts of the uranium industry and leading research centres in Ukraine and other CIS countries . The opportunity of using hardening mixes using waste as filler for the hydrometallurgical plant for stowing and immobilization when working out maps of surface tailings was proven.