Search
You are here: Articles
Articles

ACTIVE DYNAMICS OF TECHNOGENIC LANDSLIDE ON THE LEFT BOARD OF THE KHANIKOMDON RIVER (NORTH OSSETIA)

Khijsa O. Chotchaev, Dmitry A. Melkov, Ganapathy P. Ganapathy

The article is devoted to the technogenic triggering of the hazardous dynamic development of the landslide massif, which poses a threat of blocking the Khanikomdon stream with partial restrictions in the movement of residents of the mountain village of Dzuarikau. One of the main reasons for the intensive development of landslides in the Northern and Southern Jurassic shale depressions is the technogenic undercutting of slopes, caused mainly by the need of development of the mining industry or transport communications, although scientifically grounded pre-design solutions for minimizing the development of landslide processes can significantly reduce negative geoecological loads on the territory, which is especially important for the sustainable development of the mountainous areas. The aim of the work was to study the state of the landslide with modern measuring systems. Geophysical surveys were carried out by methods of vertical electrical and location-based sounding; the measurements of landslide movement were also carried out in the monitoring mode using surveys with a total station and a global positioning system GPS/GLONASS. The obtained results characterize a three-layer section of the “K” type with the thickness of a landslide high-resistivity massif of 18-21 m of crushed-loamy and gravelly composition, which is overlaid and underlain by more conductive clay strata. Geodetic observations show that the landslide body has moved throughout the entire monitoring period, but the velocities varied depending on the season. It is assumed that the seasonal variability in velocities is caused by the groundwater levels and associated pore pressures, which decrease when surface water is absent or cannot penetrate frozen landslide material, and increase when surface water from melting snow or rain penetrates the unfrozen landslide material.

Number of views: 700

DEVELOPMENT OF METHODS AND MANAGEMENT TOOLS AEROGASDYNAMICS PROCESSES AT MINING SITES

Igor I. Bosikov, Roman V. Klyuev, Valeriy N. Khetagurov, Iskandar M. Azhmukhamedov

The practical development of the algorithm for optimal control of mine ventilation was preceded by comprehensive studies of the specific features of mining sites in order to obtain their mathematical description. The latter includes the static and dynamic characteristics of objects, i.e. the relationship between input and output values.
The purpose of the research: to develop methods and management tools aerogasdynamics processes on mining sites of coalmines.
Research methods. The methodology based on the system approach; modern methods of mathematical statistics, decision theory; mathematical logic devices; factor analysis; mathematical modeling; set theory and system analysis.
To determine the dynamic characteristics of aerogasodynamic processes, experimental methods were used, divided into active and passive. The active method consists in con-structing a dynamic model of airing objects by approximating the transition curve obtained because of special effects on the airing object with an analytical expression. Statistical dynamics methods were used to obtain dynamic characteristics based on normal operation data. The method of correlation analysis was used.
Results of research: experimental verification showed that the maximum relative error of in determining the methane concentration from the static characteristic constructed using a modified technique does not exceed 10 %.
The value of the error was determined by comparing the static characteristic obtained by the modified correlation analysis method with the exact static characteristic of the airing object. The latter were found with regard to dynamic properties of the object and additive structures aerogas dynamics processes.
Conclusion. The method of correlation analysis can be used to determine the dependence of the methane flow rate on the airflow rate in the steady-state mode, i.e. the static characteristic q = f (Q) for the site and lava. To determine the static characteristics based on the data of normal operation with a limited observation interval (5-10 days), a modified method of correlation analysis is proposed.
Small values of the relative error of indicate the possibility and feasibility of using a modified correlation analysis technique to construct a static characteristic of the airing object based on random processes of methane concentration and air flow obtained during normal operation of the site.
The static characteristics C= f (Q) and q= f(Q) are widely used to determine the mathematical expectations of the methane concentration and flow rate of mining sites, in the modeling of ventilation facilities and in the analysis and synthesis of mine ventilation control systems.

Number of views: 673

APPLICATION OF THE JET SCHEME AND FLOTATION MODE WITH A VAPOR-AIR MIXTURE DURING GOLD-BEARING ORES ENRICHMENT

Sergey I. Evdokimov, Tatiana E. Gerasimenko, Azamat T. Marzoev

Increasing the economic efficiency of enrichment of refractory gold-bearing ores is possible by reducing the cost of opening sulphide gold-bearing concentrates by reducing the yield of flotation concentrate sent to pyro- or hydrometallurgical processing. It is important to maintain the achieved level of gold recovery into concentrate with a lower concentrate yield. In order to achieve this goal, the gold content in the main flotation operation is increased by mixing the rough concentrate separated from ½ part of the ore feed with another ½ part of it. Mixing in the flotation operation of products with a high level of wash ability (ability to separate) – initial feed and rough concentrate – is identical to an increase in the content of the extractable component in the original ore.
In accordance with the new regime of flotation, the process is carried out in cold slurry with bubbles filled with hot steam. The physical basis of the new flotation regime is the dependence of the surface properties of air bubbles and surface forces that determine the stability of the liquid film separating the bubble and the particle on the temperature, which increases due to the heat of the vapor-liquid phase transition. Radial oscillations of the bubble surface as a result of pressure pulsations during condensation and vapor evaporation and surface thermal flows of liquid in the wetting film are factors that provide an increase in the completeness of gold recovery and the selectivity of flotation adhesion obtained in ore flotation experiments.
In laboratory conditions, a comparison was made of the indicators obtained during the dressing of gold-bearing ores according to the factory and new schemes. It was revealed that the use of the developed technology allows, with a lower concentrate yield, to obtain an increase of 7.06% abs. extraction of gold into a concentrate of the best quality. A decrease in gold losses with flotation tailings is a consequence of an increase in the number of particles reaching the bubble surface due to radial oscillations of its surface and a weakening of the stability of the wetting film by the thermo-capillary mechanism. An increase in adhesion selectivity can be interpreted using the concept of surface forces of structural origin – an increase in the forces of hydrophobic attraction and hydrophilic repulsion with increasing temperature. The interaction of vapor bubbles with nanobubbles on the surface of the solid phase (wetting by the Cassie-Baxter mechanism) ensures efficient particle recovery by the coalescence mechanism of flotation.

Number of views: 625

THE INFLUENCE OF THE CHARACTERISTICS VARIATIONS OF THE CONCENTRATING PLANT CONTROL OBJECT ON THE IDENTIFICATION RESULTS USING THE HAMMERSTEIN MODEL

O. V. Porkuian, V. S. Morkun, N. V. Morkun, I. A. Gaponenko

As a result of the identification based on the Hammerstein model of objects of the first stage of iron ore magnetic separation, the adequacy of the model is obtained. All results of the testing of the developed identification algorithms show that the subsystem of identification of the automated process control systems of processing plants based on the Hammerstein hybrid model allows to carry out satisfactory identification of objects and, as a consequence, to improve the quality of technological processes. The study of the influence of the coefficient of various typical links on the results of identification using orthogonal parallel and parallel-recursive Hammerstein models showed that these models allow considering the differences in the properties of identifiable objects adequately.

Number of views: 551

PROSPECTS FOR THE DEPOSITS DEVELOPMENT IN OSSETIA

Vladimir I. Golik, Yuri V. Dmitrak, Oleg Z. Gabaraev, Igor A. Zasseyev

Goal. Substantiation of the ecological and economic efficiency of innovative technologies for the development of deposits of the Sadonsky ore cluster during the period of restoration of the lost industrial potential of the depressed region.
Methods. Analysis of the theory and practice of mining, with priority given to the experience in the development of North Caucasian deposits. Laboratory experiment in the study of the properties of filling mixtures and options with different activation methods, including reagent leaching in a disintegrator. Mathematical and economic modeling of the efficiency of recycling tailings utilization at the cost of commercial products, taking into account the prevented environmental damage.

Results. The information on the dynamics of mining and processing of ores from the Sadonsky deposits is presented. The results of studies of the properties of base concrete mixtures based on ore dressing tailings and local available components are systematized and generalized. The results of changes in the properties of hardening mixtures are given depending on the presence of metals in the tailings of enrichment with various activation options by alternative methods, including an innovative method of mechanochemical leaching in a disintegrator with electrochemically activated water. The equivalent of 1 kg of cement using binders from processing tailings has been determined. The advantages of mechanochemical activation of tailings in a disintegrator in comparison with the option of irrigation by irrigation using various reagents have been experimentally determined. A quantitative indicator of an increase in the strength of the compositions of hardening mixtures under equal conditions has been established. The efficiency of utilization of tailings and metallurgy has been determined as a set of effects of reducing the amount of environmental damage from storage of tailings, the cost of metals obtained during processing, raw materials for the construction industry and associated marketable products. The nomenclature of tailings processing products has been detailed. A model for determining the profit from processing tailings and metallurgy is recommended. A forecast is given at the level of engineering expertise of the prospects for tailings processing. The hardware diagram of the tailings disposal section is detailed. A universal scheme for the disposal of mining and processing waste was recommended.
Conclusion. The prospects for the development of the deposits of the Sadonsky ore cluster depend on conversion to technologies with filling voids with solidifying mixtures and leaching of metals at the processing stages. The combined mining technology will reduce the output of tailings, strengthen the base of the construction industry, eliminate the need to build a second stage of tailings and improve the environment.

Number of views: 599

INFLUENCE OF THE TYPE OF DONOR CHARGES ON THE DETONATION RATE OF LOW-SENSITIVITY EXPLOSIVES

V. A. Belin, Z. G. Mollova

The article discusses the creation, testing and implementation of new donor charges designed to initiate low-sensitivity explosives. The cast booster donor charges are made entirely of explosives obtained from the disposal of unnecessary ammunition – TNT, RDX and TEN. The donor charges differ from the mass-produced ones, and have a mass of 150 to 900 g. They also have high explosive characteristics: velocity of detonation from 7200 to 7500 m/s, density of 1.6 g/cm3, excellent water resistance and strength. Their initiating ability on low-sensitivity explosives is significantly better than the one of TNT presses. The velocity of detonation of the main charge of a low-sensitivity emulsion explosive initiated with a cast booster is up to 700 m/s higher than when initiated with a TNT presses. It is especially important when building objects in the constrained conditions, at development of mountain territories for decrease in action of shock air waves and elimination of possibility of mountain collapses and landslides In article advantage of use of cast intermediate detonators on safety of explosive works is proved at development of mountain territories. The new design allows an increase in the security of initiating the charges in the boreholes, which allows them to be initiated with two detonators simultaneously.

Number of views: 648

COMPARISON OF THE CRUSHED MATERIAL MOVEMENT MODEL IN THE BODY OF A VERTICAL CENTRIFUGAL MILL

David G. Minasyan, Alana S. Eloeva, Sergey G. Nazarov, Pavel A. Skvortsov

Introduction. Improving the performance, increasing productivity, reducing the metal consumption of grinding equipment and other mining machines is usually a very expensive process. It requires a large amount of development work, the production of prototype machines, and a large amount of experimental research. In this regard, one of the most important tasks is to simulate the movement of bulk material in operations for processing minerals in various equipment. In such modeling, the discrete element method (DEM) is widely used. The purpose of the research is to compare the models of the movement of the crushed material in the body of a vertical centrifugal mill.
Research methodology The motion of the bulk medium in a vertical centrifugal mill was modeled using two models. In the first model, the cylindrical body of the centrifugal mill was assumed to be stationary, and on its surface and on the entire surface of the rotor, conditions were set for the absence of a relative speed of movement of the crushed material. In the second model, a hydrodynamic model was used to describe the motion of a granular material as a viscous incompressible liquid with a compression ratio that depends on the pres-sure. In this model, the viscosity coefficient is represented as consisting of two terms: a constant (analogous to dynamic viscosity) and an excess pressure over hydrostatic pressure.
Research results It is established that both models give the same character of the movement of the material in the mill body. It is determined that the absolute velocity of the material movement near the walls and near the mill rotor is approximately the same for both models, but in the data obtained using the hydrodynamic model, as the material moves away from the walls and the rotor, it slows down more than for the model using the discrete element method. It is revealed that the absolute velocity of the material movement near the walls and at the axis of the mill rotor is approximately the same for both models, but in the data obtained using the hydrodynamic model, as it moves away from the walls and the rotor, the material slows down significantly more than for the model using the discrete element method.
Based on the simulation results, it can be concluded that for a more accurate simulation of the processes occurring during the rapid movement of bulk material in the grinding equipment, it is preferable to use a model using the discrete element method. It is advisable to use the hydrodynamic model for conducting a large number of search dawns or as a predicate model that will allow you to quickly set the initial velocity values for particles in a model using the discrete element method.
Conclusions 1. A hydrodynamic model of the motion of a bulk medium in a vertical centrifugal mill, represented as a viscous incompressible liquid with a compression coefficient depending on the pressure has been developed. 2. It is established that for a more correct simulation of the processes occurring during the rapid movement of bulk material in the grinding equipment, it is preferable to use a model using the discrete element method. At the same time, it is advisable to use the hydrodynamic model for conducting a large number of search calculations or as a predicate model that will allow you to quickly set the initial velocity values for particles in a model using the discrete element method.

Number of views: 565

PREDICTING THE STATE OF THE ICE BARRIER OF A VERTICAL MINE SHAFT UNDER ARTIFICIAL THAWING

Alexandra V. Kuzina, Vera N. Krynkina, Anatoliy A. Mishedchenko

At the end of the shaft penetration under the protection of the ice barrier and the termination of the process of freezing the rocks, the transition period from freezing to thawing begins. First of all, the tubing support of the trunk and the layer of rocks adjacent to the concrete support are subjected to thawing. At this time, water is pumped through the grouting holes in the tubing to check the tightness of the tubing column, after which the grouting is performed with cement mortar of the fixed space. Thus, grouting is an integral part of the work on waterproofing the support. For successful work on grouting, it is necessary to ensure the thawing of the ice barrier by a value of 1 m from the contour of the trunk in the sinking.
The necessary defrosting can be provided in various ways, including the circulation of warm air in the barrel, the supply of warm coolant to the freezing columns, etc. A program for calculating the defrosting parameters has been developed, depending on the combination of methods for supplying warm air and heated brine.
It is determined that in order to create reliable conditions for the production of plugging of the fixing space and water-proofing of the tubing support, the most favorable option is thawing by feeding warm air into the barrel and circulating the coolant at a temperature of +15°C.

Number of views: 593

SORBENT-BASED METHOD OF SOILS DETOXIFICATION FROM HEAVY METALS

Vera V. Yurak, Raphael A. Apakashev, Niyaz G. Valiev, Maxim S. Lebzin

Abstract. The sorbent-based method is one of the key methods for solving the problem of limiting the mobility of pollutants and the effective implementation of reclamation works. Despite the level of knowledge of the problem, the use of the sorbent-based method is of a fragmented experimental nature. Objective: to study the experience of implementing the sorbent-based method for the adsorption of heavy metals in order to determine the most promising compositions of sorbents for further research work on their improvement. 
Methods: General scientific methods were used, such as dialectical, historical, analysis, synthesis, comparison, grouping, as well as systematic and empirical approaches. 
Results: The presence of pluralism of definitions in relation to the term “heavy metals”was revealed. The main criterion for attribution is the relative atomic mass of more than 50 g/mol. An additional criterion is the density, which is approximately equal to or greater than the density of iron (rounded 8 g / cm3). There are other classifications that rely on threshold density or atomic mass values. It is proved that the main role of the immobilization of heavy metals is their transfer to new, more geochemical stable phases by sorption, precipitation, and complex formation processes. The widespread use of the sorbent-based method, which solves the problem of converting heavy metals into a sedentary form and difficult-to-dissolve compounds, has been identified. It is revealed that an important process affecting the mobility of heavy metals in the soil is their fixation with humus. It is established that rocks and minerals have pronounced sorption properties. The most common rocks are clays. They are characterized by a significant sorption capacity and a high specific surface area. In order to increase the sorption properties, the materials can be subjected to various modifications. Peat occupies a special place among effective natural sorbents. The development of technologies for the creation and use of new sorbents made from industrial waste is a promising direction. A method of remediation based on the use of ameliorants–stabilizers of heavy metals has been developed: among the mineral elements of the solid phase, fine clay and ferrous minerals are isolated; compost and manure are often used as organic stabilizers. The possibility of rerational use of industrial waste components as meliorants-stabilizers of heavy metals is investigated, and the sediments of water treatment at filtration stations are of interest in this regard. The remediation potential of water treatment sediments can be enhanced by joint application with natural or modified peat.

Number of views: 640

MONITORING AND MANAGEMENT OF THE RIVER’S ECOLOGICAL STATE METHODOLOGY USING INTEGRAL BIOMARKERS AND QUALITY MANAGEMENT METHODS

Gorbunova T. L., Matova N. I.

The water quality of most rivers near the settlements is below the optimal level, taking in account natural ecosystems condition and numerous needs of various users. Considering the environmental, economic and social importance of this factor, measures are required to improve natural reservoirs water quality management conducted by local civil autonomy and various levels of government. The goal of this work is to offer methodical recommendations on the system design of collecting, analyzing and forming the river’s water and ecosystems conditions database for the information support of complex management decision-making directed to accomplishment and preservation of the water bodies specified functional characteristics. Presently none of the existing methods of water environment assessment can take into account all possible biological communities’ responses to the various stress factors and their combinations impacts. For every type of impact the corresponding to it approaches in sampling and analysis methods are used; values of such methods are often difficult to collate and, especially, provide statistical evaluation of the water streams processes. The presented methods are based on the multimetric index application, which include  parameters, reflecting biological communities biodiversity and stability in mountain type rivers, tolerance degree of the constituted them water organisms to external impacts and water environment toxicity for its inhabitants.    Modern quality management, including quality of the processes, has a wide range of proven tools. The offered quality management process improvement method of the natural watersheds experiencing an anthropogenic pressure, is aiming to reach stability and guaranteed quality of the natural waters, based on the DMAIC quality management methodology and statistic quantitative methods united under the Six-Sigma approach. This article is the first in publications series devoted to the description of the methodology of the rivers ecological state monitoring and management using integrated biomarkers and quality management methods. Formed during the study organizational and methodical approaches can be applied to digital transformation of effective administrative decisions making process in sphere of water objects protection and development of the river’s catchment territory ecological planning within the project of the RF Construction Ministry “The Smart City”.

Number of views: 693
First 567891011 Last
SEARCH (ON AUTHORS OR ARTICLES)
Search the Issue

ISSN 1998-4502 (Print)                                                            ISSN 2499-975Х (Online)