rss_2.0Mining Revue FeedSciendo RSS Feed for Mining Revue Revue 's Cover Analysis of Impact-Shear Interaction of Counter Flows of Ground Loose Material in Centrifugal Disintegrator<abstract> <title style='display:none'>Abstract</title> <p>The distribution of power consumption of centrifugal two-shaft disintegrator for impact and shear destruction of material as functions of its technological and structural parameters, as well as parameters of material being ground, has been substantiated. An analytical apparatus has been developed to determine the degree of influence of each factor. Factors affecting the absolute value of the consumed power of the disintegrator have also been established. The results of the work make it possible to optimize the technological process in order to reduce the yield of bream fragments of destruction, which is observed when the share of energy of shear deformations increases, in order to obtain cuboid fractions of disintegration products. They allow to create a methodology for determining the rational parameters of a centrifugal double-shaft disintegrator.</p> </abstract>ARTICLE2021-10-11T00:00:00.000+00:00Air Quality Monitoring in Jiu Valley<abstract> <title style='display:none'>Abstract</title> <p>The paper presents air quality monitoring in Jiu Valley, which is carried out at HD-5 Vulcan monitoring station, starting with March 2010, allowing the obtaining of useful data for the rapid identification of polluted areas and for taking strategic decisions by competent factors and tactics to combat and prevent pollution. After highlighting the pollution sources in Jiu Valley, we present both the evolution of hourly and / or daily values of pollutants recorded at the automatic HD-Vulcan air quality monitoring station during 2020: SO<sub>2</sub>, NO<sub>2</sub>, CO, gravimetric PM<sub>10</sub>, Pb, Cd and Ni, but also the evolution of air quality for quality indicators, monitored in Hunedoara County (including Jiu Valley, at HD-5 station), during 2010-2020.</p> <p>Taking into account the average annual values of pollutants recorded in 2020 at HD-5 Vulcan station, the paper calculates air quality indices for each pollutant and then indicates air quality throughout Jiu Valley in 2020, establishing that air quality is good in this area, with a very low level of pollution and no effect on humans, ecosystems and materials.</p> </abstract>ARTICLE2021-10-11T00:00:00.000+00:00Complex Technologies of Brucitic Limestone Capitalization<abstract> <title style='display:none'>Abstract</title> <p>The paper presents a synthesis of the research consisting in a complex capitalization of a brucitic limestone deposit from Romania, in environmental protection, respectively of the complex processing possibilities for using the final products could in a very well defined direction such as: the getting of MgO with 99% purity from a brucitic concentrate with 38-40% MgO content; the getting of a fertilizer containing struvite, limestone and microelements with benefit effects on the acid soils amelioration and on plants growth. The research allowed the establishing of a complex system of three technologies, respectively, one of brucitic limestone processing, the second of magnesia obtaining by brucitic concentrate leaching with carbon dioxide and the third, that of getting a double-role agricultural fertilizer (manure for plants growth and acid soils neutralizer).</p> </abstract>ARTICLE2021-10-11T00:00:00.000+00:00Environmental Impact on Soil and Water Because of Mining Activities in the Eastern Part of Jiu Valley<abstract> <title style='display:none'>Abstract</title> <p>Analysing environmental impacts of mining activities involves detailed studies of the interactions between technological activities/operations carried out in a mining operation and environmental components affected by them. In order to carry out a more complex environmental impact assessment caused by mining in the eastern part of Jiu Valley on soil and water 4 mining units have been considered in the study, these being mining unit Lonea, Petrila, and Livezeni with their belonging dumps.</p> <p>Main objective of this research is to analyse the impact caused by mining activities in Eastern part of Jiu Valley by the method of impact networks according to the model “causes - pressures, depreciation of the quality of environmental factors – affected parameters - impact”. Thus, impacts caused by the mining industry were identified based on the top-down typology, being shaped impact networks for underground coal exploitation and sterile material storage on the surface. The metal content of the dumps was also analysed in order to assess the degree of metals soil enrichment compared to the reference concentration of a blank sample. The analysis of the influence of the local rainfall regime aims to highlight the leaching potential of heavy metals in the body of the dump and the possibility of analysing the scenarios of extension of the pollution phenomenon to the saturated area. The study is addressed to researchers, environmental engineers, hydrogeologists and geologists who want to deepen the study of transfer mechanisms of contaminants from dumps to watercourses receiving areas and their dispersion in unsaturated and saturated areas.</p> </abstract>ARTICLE2021-10-11T00:00:00.000+00:00A Possible Tunnels Execution Technology on Subsection E2 of the Highway A1<abstract> <title style='display:none'>Abstract</title> <p>The paper aims to establish the design elements of the tunnels to be executed on subsection E2 of the Lugoj-Deva highway section, an integral part of the A1 highway. From the multitude of problems related to the execution of a tunnel, the paper investigates the following aspects: geotechnical investigations of the areas to be crossed by tunnels, analysis of tunnel stability, static checks of the final support/lining and, finally, a possible technology for their execution.</p> </abstract>ARTICLE2021-10-11T00:00:00.000+00:00Research on the Recovery of Copper from Metallurgical Slag<abstract> <title style='display:none'>Abstract</title> <p>Metallurgical slag is one of the most common industrial wastes. Many of these wastes are not stable over time, by reacting with water and air, continuously generating emissions of heavy metals. Metallurgical slag processing is necessary for at least two reasons: reducing pollutant emissions and broadening the raw material base. The recovery of these slags is very difficult because they are the result of metallurgical processes that aimed to fix metals considered impurities in chemical matrices as stable as possible. This paper presents the initial research on the behavior of metallurgical slags against different leaching technologies.</p> </abstract>ARTICLE2021-10-11T00:00:00.000+00:00Determination of Diagnostic Parameters of Power Plants Based on Internal Combustion Engines<abstract> <title style='display:none'>Abstract</title> <p>The presented article shows a method for finding monitored parameters for creating a diagnostic system for autonomous power sources based on spark ignition engines and diesel engines. The classification of structures of autonomous power sources based on internal combustion engines has been carried out. The analysis of the design features of the most common back-up power sources on the market based on internal combustion engines (ICE) indicates the widespread use of generators with a synchronous alternator. The analysis of the design features of autonomous power supplies has made it possible to develop logical models for different designs. The influence of the occurrence of a faulty state of each element on other elements of the systems is analyzed, and the results of the analysis are summarized in tables. An informative Claude Chenon criterion is proposed for finding the optimal number of diagnostic parameters among an infinite number of possible combinations of physical parameters that characterize the system. When solving the problem, a hypothesis was proposed about the equiprobability of cases of exit from the working state of each of the elements of the system. The use of Claude Chenon allows you to find the parts that make up the generators, which with maximum efficiency reduce the degree of uncertainty in the system. After determining the residual entropy, the parts of the system are selected, the state of which should be monitored by the diagnostic system. For such parts of the system, diagnostic parameters are found and methods for obtaining them are indicated.</p> </abstract>ARTICLE2021-10-11T00:00:00.000+00:00Improving Technical-Economical Performance at Praid Saline Way of Rock Salt Roadheader Mechanized Mining<abstract> <title style='display:none'>Abstract</title> <p>Increasing the mining depth at Praid Saline and implicitly the state of stresses and strains determines an increase in the dimensions of resistance structures (pillars and ceilings). Furthermore, the seismic effect generated by the detonation of explosives contributes to the degradation of resistance structures. In order to reduce the destructive effect of drilling-blasting technology a proposal is made for the implementation of mechanized salt cutting technology which makes use of a roadheader. This article emphasizes the technical-economical implementation advantages of exploitation from the lower horizons of the New Sector, those of mechanized mining with a roadheader as opposed to the classical technology of drilling-blasting.</p> </abstract>ARTICLE2021-10-11T00:00:00.000+00:00The Influence of Physical Parameters on the Mechanical Characteristics of Some Volcanic Magmatic Rocks of the Andesite Type<abstract> <title style='display:none'>Abstract</title> <p>The factors that influence the strength characteristics of rocks can be different in nature, being divided into external and internal factors. The mechanical properties of hard rocks are a result of geological, physical and chemical factors. In order to highlight the physical parameters that influence the strength characteristics of the rocks, in this paper there were analyzed six types of volcanic magmatic rocks such as andesites. In terms of stress behavior, rocks are directly influenced by their physical properties, such as volumetric density, porosity, compactness, moisture and the degree of alteration of mineral components. For this purpose, several sets of tests were performed to determine the physical and mechanical characteristics of the rocks, based on which it was possible to analyze how the physical parameters influence the strength characteristics.</p> </abstract>ARTICLE2021-07-15T00:00:00.000+00:00Update of the Ventilation Network Related to Livezeni Mine<abstract> <title style='display:none'>Abstract</title> <p>The ventilation networks are associated with the set of underground mining works used for the extraction of useful mineral substances. Over time, the ventilation networks involve a change in the structure due to either the expansion or restriction of the mining works structure. For the establishment of air flows at the level of each active mining work, specialized programs are used at international level. These programs allow the modelling and solving of complex ventilation networks. The most advanced specialized programs are those from the VENTSIM range. The paper presents the updating of the ventilation network related to Livezeni mine, with the help of the VENTSIM program.</p> </abstract>ARTICLE2021-07-15T00:00:00.000+00:00Analysis of Methods for Preventing and Fighting the Self-Heating Phenomena of Coal Used in Jiu Valley Mines<abstract> <title style='display:none'>Abstract</title> <p>This paper deals with the analysis of two cases of coal self-heating from two longwall mining within the coal exploitations belonging to Complexul Energetic Hunedoara, phenomena that started similarly but later evolved differently, as a result of prevention methods applied or not applied in each case. For the analysis of these self-heating phenomena, the data collected after the occurrence of the first signs were used, respectively the emission of carbon monoxide in the longwall mining area, until the moment of desertion and closure of the longwall with dams in the first case and eradication of the phenomenon in the second case. By analyzing in parallel the two cases, several conclusions are drawn which may help to counteract these types of phenomena that may occur in the longwall exploited in similar conditions.</p> </abstract>ARTICLE2021-07-15T00:00:00.000+00:00Using the PIV Techniques in the Expertise of Gas Explosions<abstract> <title style='display:none'>Abstract</title> <p>Given the possibilities offered by PIV systems, it was considered appropriate to test them in the study of the formation of explosive atmospheres. In this sense, within the INCD INSEMEX Petroșani laboratories, a test stand was created subject to the conditions of applying PIV techniques. Thus, this stand was built of transparent materials, having the possibility to introduce, in the inner volume, the suspended particles and the combustible gas, being at the same time able to be sectioned by the light plane generated by a laser source and to provide the recording conditions using a CMOS camera. The physical experiments concerned both the situation of a normal atmosphere inside the test stand and the situations of the appearance of a fuel gas leak and an efficient source of initiation of the formed explosive atmosphere.</p> </abstract>ARTICLE2021-07-15T00:00:00.000+00:00Monitoring and Forecasting of Surface Deformation at Victoria and Cantacuzino Mines<abstract> <title style='display:none'>Abstract</title> <p>The underground mining of the rock salt deposit from Slănic started in 1665, with the Old Mines and continued in 1970, with Victoria Mine, then in 1993, with Cantacuzino Mine. The mining method applied at Victoria and Cantacuzino mines was the one with small rooms and square pillars, with which over 9.7 million m3 of rock salt were extracted. This very large volume of underground mining voids led to the convergence of the underground excavations and thus to the deformation of the surface. This article presents the analysis of the measurements of surface displacement and the prediction of its subsidence over time. Also, the main factors that contributed to the deformation of the surface are analyzed, namely: the dimensions of the underground voids, the mining depth, the geomechanical characteristics, the tectonics and microtectonics of the deposit, the hydrogeology and the effect of blasting.</p> </abstract>ARTICLE2021-07-15T00:00:00.000+00:00Modeling of the Complex Ventilation Network Related to Livezeni Mine<abstract> <title style='display:none'>Abstract</title> <p>In order to ensure the microclimate conditions for the exploitation of useful mineral substances underground, it is necessary to ensure the control of gas emissions from the field and from the exploited space. For this it is necessary to ensure a balanced air flow at the level of each active mining work in order to dilute the gases. Specialized programs are used to ensure the optimal distribution of air flows at the level of each mining work. The paper presents the modelling and solving of the ventilation network related to Livezeni Mine with the help of the 3D CANVENT program.</p> </abstract>ARTICLE2021-07-15T00:00:00.000+00:00Spatial Representation of Useful Minerals Deposits<abstract> <title style='display:none'>Abstract</title> <p>Starting from the fact that in the mining industry and in general in the field of underground constructions, the topographic activity, regardless of which of its manifestations, conditions and substantiates the achievement of economic and technological objectives, implicitly resulting in the dependence between topographic precision and qualitative and quantitative performance of mining. The level at which the professional responsibility of the topographic activity, as a whole is engaged in the achievement of some proposed objectives, depends on the framework resulting from the technological complexity of the mining activity in the conditions of its restructuring and efficiency. Spatial representations of useful mineral deposits in the earth's crust, which meet the quality conditions necessary for the design of underground mining works, can be used to choose the most efficient methods of opening, preparation and exploitation of useful mineral deposits. These analyzes are the basis for the realization of underground topographic networks that have a precise connection with the topographic base at the surface. The use of stereographic projection and stereographic networks can be achieved by faithfully representing the tectonics and positioning of deposits of useful mineral matter inside the earth's crust.</p> </abstract>ARTICLE2021-07-15T00:00:00.000+00:00The Impact of Exploiting Lignite in Lupoaia Open Pit on Environmental Water<abstract> <title style='display:none'>Abstract</title> <p>The impact of extracting lignite in Lupoaia open pit over waters is local and regional, and temporary. The hydrographic network in Lupoaia open pit depends on River Motru, with its afluents, Ploștina and Lupoița Valley Rivers. The aquifers are to be found in the coal layers V-XII, mainly of sands formation. The impact over water in Lupoaia consists of water pollution and of changes in both the quality and the quantity of ground and surface waters. The surface waters are polluted resulting in industrial wastewaters, household wastewaters and waste rainwater. The wastewater is polluted within maximum admitted limits. The quality of groundwaters is influenced and modified by extracting coal resulting in the extinction of some aquifers. Environmental risks that can occur when extracting lignite are water floods, landslides, disasters which can be prevented by building guard channels around the open pit. The actions for reducing the impact are, in general, accomplished through monitoring both the water pollutants and the morphological changes caused by extracting lignite. That is why wastewater treatment plants must function. The impact of the activity in Lupoaia open pit over the hydrographic net of the area is to be observed during the entire extracting period, and monitoring this activity is highly demanded by the European environmental protection laws.</p> </abstract>ARTICLE2021-07-15T00:00:00.000+00:00The Share Distribution and Precision Evaluation in Underground Topographic Routes and Networks<abstract> <title style='display:none'>Abstract</title> <p>The underground topographic works of elevating and drawing are necessary for the execution of underground works (mining, hydrotechnics, communications, etc.) Fulfilling these works efficiently and safely requires an advance study for the precisions in topographic support routes and networks. This paper aims to establish the share distribution correlated with the underground works distribution.</p> </abstract>ARTICLE2021-07-15T00:00:00.000+00:00Environmental Impact Assessment Related by Energy Sector in Rovinari Mining Area<abstract> <title style='display:none'>Abstract</title> <p>In this article an impact assessment is carried out, generated by activities in the energy sector related to Rovinari mining area. Energy-related activities in this area are carried out by open pit mining activities in the context of Tismana, Roșia, Pinoasa, Peşteana and Rovinari locations and Rovinari thermal power plant. Some information that has formed the input for the author’s approach has been provided by SC. Complexul Energetic Oltenia SA (CEO) and S.C. Institute of Scientific Research, Technological Engineering and Mine Designs on Lignite S.A. Craiova (ICSITPML) which has been processed, analysed and used for the presented environmental impact assessment. Two methods from specialized studies have been used for the impact assessment, namely: the Matrix Method for Rapid Impact Assessment (MERI) and the Method for Integrated Quantitative Impact and Risk Assessment of Environmental Pollution (EIRM). Based on the analysis carried out, it can be concluded that the activity in this sector does not lead to significant negative effects strictly associated with it.</p> </abstract>ARTICLE2021-07-15T00:00:00.000+00:00Solubilization Processing of Ashes Power Plant<abstract><title style='display:none'>Abstract</title><p>The paper presents the attempts of acid and alkaline solubilization of the power plant ashes, using different chemical reagents, at different concentrations. Due to the mineralogical content of these ashes, was elaborated a technological flow for the recovery the iron minerals, resulting an ferrous concentrate containing noble metals. For their recovery from ferrous concentrate, were studied properties of gold, silver and platinum, the conclusion being that these chemical elements can be extracted, in economic conditions, with sodium hypochlorite.</p></abstract>ARTICLE2021-04-13T00:00:00.000+00:00Correlation of the Local Projection System with the National System<abstract><title style='display:none'>Abstract</title><p>In areas with border extension (localities, mining areas, hydrotechnics, etc.) it is advisable to establish the positions of the points in a local system, the methods used being simpler and the results more precise. However, it is necessary to transcalculate the coordinates from the local system to the national projection system. A transcalculation method is assumed to ensure efficiency and accuracy.</p></abstract>ARTICLE2021-04-13T00:00:00.000+00:00en-us-1