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The negative effect made by mining enterprises on the natural environment has complex origination. The intensive pollution is observed because of the influence of mineral deposits open-pit mining on the atmosphere, water resources and landscape complexes. Complex processes of environmental anthropogenic changes caused by open pits’ operations have...
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... Since rock and coal transportation are organized as separate traffic flows, which have only one thing in common -excavation and loading equipment, then calculation of indicators for these traffic flows is performed separately. The situation is the same for both surface and underground mining [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][21][22][23][24][25][26][27][28][29], as well as for various geo-environmental issues where consideration of cargo flows of different genesis is required [32,33,[35][36][37][38][39][40]. ...
The study of the technology of excavation and loading operations at more than 15 open pit mines of Kuzbass with the use of trucks shows the general similarity of the technological process in terms of providing transport operations of haul trucks: loading is often carried out at the level of excavator standing, less often – below the level of excavator standing. The predominant scheme of haulage haul truck approach for loading – dead-end, less often – circular, very seldom – through. When digging trenches and working narrow strips, it is difficult to approach excavators due to insufficient width of the site for turning, the necessity of safety and barrier shafts, etc. In this case, the maneuvering time of the haul trucks and their exchange time for loading depends considerably on the skills of the haul truck driver. Considering that the mining operations at the open-pit mines are gradually going deeper and deeper, there is no reason to assume that the width of the vehicle turning sites will increase in the future. Therefore, the use of autonomous heavy platforms, which do not require turning during their delivery for loading, seems very promising in the so-called cramped working conditions. In this work the question of working time losses at haul trucks exchange at loading in real conditions is briefly considered, dependence of average speed of movement and time of trip on a distance of transportation is resulted.
... All organizational tasks in mining [1][2][3][4][5][6][7][8][9][10][11][12][13] (open-cut mining in general) are subdivided into planned (prescheduled, scheduled for implementation) and unplanned (to eliminate violations of the technological process and the resulting unscheduled downtime of equipment) [14][15][16][17][18][19][20][21]. Unplanned downtime of excavators account for 20-50% of the calendar time [22][23][24], and 30-50% of unscheduled downtime refers directly to the process of excavation and loading [25][26][27][28]. ...
Automobile transport currently dominates the transportation of overburden and coal at open pit mines. Its share has been steadily growing since the 1970s. This is due to objective reasons, first of all, a rather limited area of application of railway transport: a significant transport distance, a large cargo traffic and a small depth of the quarry. First of all, it concerned the depth of open-cut mines, because when deepening the quarry for one trench it was necessary to extract considerable volumes of overburden to provide accommodation of transport berms because of the big radius of curvature of a railway track, which reached 200 m. Therefore, given the fact that open-pit mining went to a greater depth at almost all enterprises, there was a widespread abandonment of rail transport for intra-pit transportation in favor of automobile transport. For various reasons, a fairly economical and promising mode of transport – conveyor transport – has not become widespread at Kuzbass coal mines. Not least of all, this is due to climatic conditions, as well as the complexity of mining and geological conditions of the Kuznetsk Basin, which are among the most complicated in the world. Suffice it to say that more than 80% of coal seams have a complex or very complex structure. Therefore, the problem of research and description of the key characteristics in open-pit mining is very urgent.
... Conventional methods for the treatment of oily wastewater include physical, physical-chemical, chemical, and biochemical methods [10]. Physical methods mainly include oil traps and coarse-grained, air flotation, and hydro-cyclone methods [11], etc. It uses the incompatibility and specific gravity of oil and water, which are different, suitable for removing large particle size oil slicks and dispersed oil [12,13], as well as most of the solid particles in wastewater. ...
In the present study, a high-efficiency petroleum hydrocarbon-degrading bacterium MX1 was screened from petrochemical wastewater sludge, and MX1 was identified using morphological, physiological, and biochemical experiments and combined with 16S rDNA. Results showed that the the MX1 strain belongs to Enterobacter sp. The degradation conditions were an incubation time of 18 days, temperature of 30 °C, pH of 7, and salinity of 2% (w/v), and the degradation proportion was 37.41% for 7 days. The combination of microwave and ultraviolet mutagenesis yielded the strain MXM3U2. The mutant strain had a petroleum hydrocarbon breakdown efficiency of 56.74% after 7 days of culture, and this value was 51.66% higher than the original strain. The number of strains and the rate of degradation of n-alkanes (C16, C24, C32, and C40) decreased steadily with the increase in carbon chains in the degradation test. GC/MS (Gas chromatography mass spectrometry) results showed that in the process of degrading crude oil, the hydrocarbons with carbon number C < 24 were degraded first, followed by hydrocarbons with carbon number C > 24. The strains had a good degradation effect on pristane, naphthalene, and phenanthrene. In this study, a high-efficiency petroleum hydrocarbon-degrading bacterium was screened via microwave-ultraviolet composite mutagenesis technology.
... It is proved that at a certain set of input design parameters the output of a haul truck will depend only on the bucket capacity of the excavator used and the angle of its turn for unloading. Also, we should take into account physical and mechanical properties of excavated rock [32][33][34][35][36][37][38][39][40][41][42][43]. The cycle time and other components are assumed to be the same as in the previous calculation, because in the first place we can only get a qualitative picture of the change in the final performance of the dump truck at the current moment. ...
When studying the influence of excavator bucket capacity on haul truck loading time, it is necessary to assess the technical and economic performance of the complex. If the cost of the machine shift of the complex will not cover the increase in productivity, then it is inexpedient to use this complex. This issue requires further, more detailed study and performance of detailed technical and economic analysis. Also, it is necessary to consider classical recommendations about ratio of excavator bucket capacity and haul truck body. It should be noted that at present, there is a significant divergence in the size range of excavators: powerful, with a large capacity bucket, rope shovels are used for mining the coalless zone; small maneuverable hydraulic shovels – for mining the coal-bearing zone. In this paper, we will try to combine the first and the second: consider hydraulic excavators with maximum bucket capacity, which is reasonable to use when mining overburden. In addition, a detailed study of the options of mutual arrangement of excavator and haul truck has not been performed until recently, this work is intended to fill this gap.
... One of the most acute problems that appears during the process of development of mineral deposits is huge amount of wastewater polluted with different chemical compounds [1][2][3][4]. For enterprises using open-pit mining method the list of contaminating components includes such components as nitrogen compounds, mostly in nitrate form. ...
The main purpose of the work was to determine the methods of mining enterprises wastewater secondary treatment from nitrogenous compounds. The chemical analysis of wastewater was carried out, and substances with exceeding concentrations were established. The accumulating power of indigenous species of higher aquatic vegetation has been estimated. The absorption regularities of nitrates of duckweed (Lemna minor) in solutions with different concentrations were determined. The expediency of duckweed cultivating with the aim of phytoremediation has been proved.
Quarry automobile transport is most important in the transportation of overburden and coal in open-cast mining operations. In this article, based on the existing analysis of the use of classic haul trucks, the change in their output is determined by some influencing factors: the type of loading of the rock mass and the bucket capacity of the excavator used. It is taken into account that when loading an unmanned dump truck, there is no need to maneuver the vehicle, which increases output, especially with a small haulage arm. Some output calculation results are given and areas for further research are identified.
The growing demand for process improvement and cost reduction has motivated many studies involving modifications in conventional devices. The filtering hydrocyclone is a non-conventional hydrocyclone that combines filtration with centrifugal separation to reduce energy costs and increase separation efficiency. In the present work, an optimization study was developed using Differential Evolution (DE) algorithm to obtain a filtering conical hydrocyclone (FCoH) categorized for thickening purposes (minimum split ratio) with low energy consumption (low Euler number). A performance comparison showed that FCoHs had an Euler number that was up to 40% lower than those found in the conventional hydrocyclones of the same geometry. The filtering hydrocyclone geometry obtained in the optimization study, named FCoH-OTS, resulted in the lowest split ratio (S = 9.59%) and Euler number (Eu = 665) among the 25 different configurations investigated in this research. The optimized configuration led to reductions of 28.6% in the split ratio and 49.5% in the Euler number compared to the hydrocyclone from the experimental design with the lowest split ratio. The low values obtained for the split ratio and Euler number confirmed the expectation of a hydrocyclone for thickening purposes with low energy consumption.
The issue of wastewater treatment in open-pit mining of mineral deposits is associated with great difficulties. Due to the constant tightening of requirements for the quality of discharged wastewater, its treatment in the sedimentation reservoirs and clarification ponds does not ensure the achievement of MPC values; in addition, these treatment facilities occupy significant areas of land. It should also be noted that the open-pit mines, as a rule, have several water outlets remote from each other, besides changing their location as the development of mining operations proceeds. For example, OJSC "UK "Kuzbassrazrezugol" has more than 30 places of water use, taking into account that the company structure includes 7 open-pit mines. In the article some results of analyses of pit waste water before and after its treatment in artificial filtering massifs at the mining enterprises of Kuzbass are presented. Preliminary dependences of changes in pollutant impurities in quarry water on different composition of coal waste have been established.
Technologically contaminated water, formed during processing of coal slurries, finds its application in modern technological cycles of coal enrichment. Limitation of use of untreated recycled water of coal concentration plants is caused by a high degree of its mineralization by various salts, presence of insoluble solid particles and presence of flotation reagents, coagulants and flocculants. Part of technical water purified from mineral and organic contaminants can be used in heating systems and heat exchange equipment of industrial enterprises, including the coal industry. For this purpose, it is necessary to reduce the scale-forming ability of service water (to reduce the content of soluble calcium and magnesium salts in water). One of the most effective and advanced methods is the stabilization treatment of water with an electric field. In addition, this method is environmentally safe, low-cost and simple. The article gives the foundation of the method of stabilization treatment of recycled water of concentrating plants by an electric field, a description of the methodology of the laboratory experiment for scaling reduction, and the analysis of the results.
One of the methods of increasing the efficiency of dragline operation is to optimize their work when mining the end sections of the cuts. This is especially important when the length of the work front is relatively short. With mining operations going deeper, and the complication of mining and geological conditions of bedding, it often becomes necessary to mine shorter face sections. However, as a rule, design bureaus do not take into account and do not visualize excavation of end sections, because these are, in fact, special cases of standard excavation schemes. Nevertheless, it significantly complicates the organization of mining operations due to the need to create routes for draglines to ascend and descend to the dump tiers. Scientific literature does not pay enough attention to this issue due to its complexity and the need for a full-scale field experiment, which in modern conditions is often very problematic. This article establishes the relevance of the above-mentioned issue and identifies directions for further research.
