-
Date submitted2024-04-11
-
Date accepted2024-11-07
-
Date published2025-01-17
Thyristor booster device for voltage fluctuation reduction in power supply systems of ore mining enterprises
The article is devoted to solving the problem of voltage fluctuations in the power supply systems of ore mining enterprises. The connection of high-power consumers with abruptly variable operating mode (for example, high-voltage mining excavators) causes voltage fluctuations and sags, disabling electrical equipment, communication, and automation devices in the 6-10 kV distribution network, which disrupts technological processes, etc. The use of existing solutions and methods to reduce voltage variations caused by dynamic loads is not effective. To solve the problem, booster transformers with high-speed thyristor switches can be used to work out switching the control steps towards increasing or decreasing the voltage. The authors offer a new circuitry solution for a thyristor booster device (TBD) with a pulse-phase control method. The purpose of the research is to determine the control laws of TBD, which enable to effectively reduce voltage fluctuations from dynamic load in the power supply systems of mining enterprises. The article provides a schematic diagram of the TBD and describes the principle of operation of the device. Some modes of increasing and decreasing the output voltage of the TBD, as well as the basic mode (without voltage addition) are provided. Mathematical modeling of TBD control processes was carried out and adjustment characteristics were set taking into account the load power factor. On a simulation computer model of a 6 kV electric network with a dynamic load, the verification of the adjustment characteristics of TBD obtained during mathematical modeling was carried out. Based on the research results, the laws for regulating the output voltage of TBD were established. The TBD effective control range with normal permissible limits of odd harmonics have been determined. The conducted research will make it possible to implement the device control system.
-
Date submitted2024-05-30
-
Date accepted2024-10-14
-
Date published2024-11-12
Thermodynamic modelling as a basis for forecasting phase states of hydrocarbon fluids at great and super-great depths
The possibility of discovering oil and gas occurrences at great (more than 5 km) and super-great (more than 6 km) depths is considered in two aspects. The first one is the preservation conditions of large hydrocarbon accumulations forming at depths to 4 km and caused by different geological and tectonic processes occurring at great and super-great depths with partial oil-to-gas transformation. It was ascertained that among the factors controlling preservation of liquid and gaseous hydrocarbons are the temperature, pressure, subsidence rate (rate of temperature and pressure increase), time spent under ultrahigh thermobaric conditions, and initial composition of organic matter. The possibility of existence of liquid components of oil at great and super-great depths is characteristic of sedimentary basins of China, the Gulf of Mexico, the Santos and Campos basins on the Brazilian shelf, and in the Russian Federation it is most probable for the Caspian Depression, some submontane troughs and zones of intense accumulation of young sediments. Determination of critical temperatures and pressures of phase transitions and the onset of cracking is possible using the approach considered in the article, based on estimation of organic matter transformation degree, kinetic and thermobaric models taking into account the composition of hydrocarbon fluid. The second aspect is the estimation of composition of hydrocarbons associated with rocks forming at great depths or rocks transformed under conditions of critical temperatures and pressures. This aspect of considerable science intensity can hardly be considered as practically significant. The study focuses on the investigation of the possibilities of thermodynamic modelling and the use of alternative methods for studying the transformation degree of liquid formation fluid into components of the associated gas through the example of two areas with identified oil, condensate and gas accumulations.
-
Date submitted2024-05-02
-
Date accepted2024-06-03
-
Date published2024-07-04
Iron ore tailings as a raw material for Fe-Al coagulant production
The paper presents the results of experimental research into the recovery of Fe-Al coagulant from iron ore tailings (IOTs). The variables investigated in the laboratory tests included sulphuric acid concentration, temperature, leaching time, solid/liquid phase ratio (S:L) and the presence of stirring. The experiment determined the composition of the coagulant and the solid residue after leaching. The maximum iron content in the solution after leaching was obtained using 40 % H2SO4 at a temperature of 100 °C (or with stirring at 75 °C) and a contact time of 60 minutes. In this case, the iron yield was at the level of 25 % of the total content in the iron ore tailings. Chemical analysis of the solution obtained after leaching showed Fe and Al sulphate contents of 11 and 2 % respectively. In the next step, the efficiency of the coagulant was evaluated on model solutions of colour. The experimental results showed that the coagulant obtained from the iron ore tailings can be used for wastewater treatment in a wide pH range from 4 to 12 pH units. The solid residue after leaching is a fine-grained powder rich in silica, which can potentially be used as an artificial raw material in the construction industry. The research carried out in this thesis has shown that the extraction of coagulants from iron ore tailings can be considered as a way to extend the production chain of iron ore mining and to minimise the amount of tailings to be stored in tailing ponds. The technical solution presented in this work allows to comprehensively solve the problem of environmental protection by creating new target products for wastewater treatment from IOTs.
-
Date submitted2023-03-14
-
Date accepted2023-10-25
-
Date published2024-04-25
Predictive assessment of ore dilution in mining thin steeply dipping deposits by a system of sublevel drifts
The purpose of research is the study of stress-strain state of marginal rock mass around the stope and predictive assessment of ore dilution with regard for changes in ore body thickness in mining thin ore deposits on the example of the Zholymbet mine. Study of the specific features of the stress-strain state development was accomplished applying the methodology based on numerical research methods taking into account the geological strength index (GSI) which allows considering the structural features of rocks, fracturing, lithology, water content and other strength indicators, due to which there is a correct transition from the rock sample strength to the rock mass strength. The results of numerical analysis of the stress-strain state of the marginal part of the rock mass using the finite element method after the Hoek – Brown strength criterion made it possible to assess the geomechanical state in the marginal mass provided there are changes in ore body thickness and to predict the volume of ore dilution. It was ascertained that when mining thin ore deposits, the predicted value of ore dilution is influenced by the ore body thickness and the GSI. The dependence of changes in ore dilution values on the GSI was recorded taking into account changes in ore body thickness from 1 to 3 m. Analysis of the research results showed that the predicted dimensions of rock failure zone around the stopes are quite large, due to which the indicators of the estimated ore dilution are not attained. There is a need to reduce the seismic impact of the blasting force on the marginal rock mass and update the blasting chart.
-
Date submitted2022-06-02
-
Date accepted2022-07-21
-
Date published2022-10-05
Substantiation of the optimal performance parameters for a quarry during the stage-wise development of steeply dipping ore deposits
- Authors:
- Sergey I. Fomin
- Maxim P. Ovsyannikov
The use of stage-wise schemes in the development of deep quarries is one of the ways to increase the economic efficiency of mining a deposit and determining the optimal stage parameters remains an urgent task. Such parameters are stage depth, bench height, block length, etc. However, there is a wide range of values for these parameters. Therefore, to select the optimal values and evaluate the effectiveness of design solutions, it is advisable to use the net present value, which is an international notion. As a result of the analysis of data on deposits, a large number of variable indicators can be identified that presumably affect the efficiency of mining. The article proposes to divide all parameters of the quarry mining into two types: mine engineering and economic. The importance of each of them is determined by the measure of influence on the net present value. Thus, to assess the measure of influence of mining indicators, the average values of each of them are taken, and as a result of the alternating change of one parameter under study, the measure of its influence on the discounted income received is estimated. The results of the analysis of relevant factors, their evaluation and comparative analysis are important indicators that significantly affect the design decisions made and the effectiveness of the investment project.
-
Date submitted2018-06-28
-
Date accepted2018-09-15
-
Date published2018-12-21
Causes of fluid entry absence when developing wells of small deposits (on the example of Khadum-Batalpashinsky horizon)
- Authors:
- R. A. Gasumov
A promising direction for the development of the oil and gas industry is the drilling of small hydrocarbon fields, which constitute two thirds of Russia's total hydrocarbon reserves. When choosing an effective method of development and assessing the potential of small fields in Eastern Ciscaucasia, which are characterized by complex mining and geological conditions with abnormally high reservoir pressures and temperatures, it is necessary to determine the optimal amount of oil production taking into account the flow of edge water under elastic water drive. The article discusses the reasons for the lack of inflows of reservoir fluids in wells during their development, which are due to complex unconventional fractured clay reservoirs in the lower Maykop deposit and the presence of loose rocks in the section of the reservoir. The results of studies of the influence of technological and geological factors on the poroperm properties of the Khadum-Batalpashinsky reservoir are described, zones of rock softening are revealed, the intervals with bottom water and their influence on the well development process are specified. It has been established that the state of the hydrodynamic system of the field depends on the introduction of the bottom and edge waters of the sedimentation basin of the East Stavropol Depression. Oil deposits in the Khadum and Batalpashinskaya suites initially work in an elastic and then in an elastic-water drive mode. The main reasons for the lack of inflows of formation fluids into wells are the low reservoir properties of clay fractured reservoir rocks; clogging of the fracture capacity of reservoir rocks at the drilling in as a result of penetration of drilling mud and its filtrate deep into the reservoir; inflow of formation water from an overlying aquifer with abnormally high formation pressure; the closure of cracks in the clay reservoir due to a sharp decrease in pressure caused by the lowering of the slotted filter into the well; secondary dissection of productive layers by perforation during repression on the formation in a liquid medium with the presence of a solid phase and high density.
-
Date submitted2017-12-28
-
Date accepted2018-03-03
-
Date published2018-06-22
Special features of a structure of technical operations for peat excavation with stage dewatering
- Authors:
- E. A. Kremcheev
A method of development of a technology of peat extraction for intensifying of dewatering which involves drying of peat raw materials in thick layers with a layer-by-layer harvesting into large-sized roll with further delivery to the field storage unit of the enlarged sizes is presented in the paper. Throughout the year storage raw materials may be transported to the customer or to the shopfloor for further processing. Considering dimension and mass characteristics, a crumbed peat of various moisture capacity is a major type of products to be of high demand. On the basis of the results of scientific studies regarding gravity dewatering of peat and its drying in field environment, the ways of intensifying of field dewatering of peat for extraction at shallow-peat lands and fine-limit fields are proposed. The presented results of the experimental performance of a technology of peat drying in thick layers with a layer-by-layer harvesting indicate an increase of seasonal harvesting and a decrease of the influence of unfavorable meteorological factors on the stability of the extraction process. Performed investigations allowed to develop a structure of technical operations for peat excavation with the stage dewatering in spreading and intermediate storage units providing rational state of the extraction process regarding a complex of technical factors. A suggested scheme of a process area for a primary and secondary period of deposit exploitation by a technology of peat excavation is considered.
-
Date submitted2014-10-27
-
Date accepted2014-12-21
-
Date published2015-08-25
Productivity of ore and placer gold deposits of the priamur province
- Authors:
- V. A. Stepanov
- A. V. Melnikov
The article discusses ore and placer gold deposits of the Priamur province formed as a result of the Late Mesozoic collisions of geoblocks of the south-eastern framing of the Siberian craton and the Amur composite massif. Metallogenic zoning of the province displaying metallogenic zones and ore-placer sites is described. The article shows that the Priamur province is one of the main gold-bearing provinces of Russia with the level of gold ore (about 180 tons) and placer (about 1132 tons) gold. The predominance of placer gold in gold mining indicates significant opportunities to identify new gold deposits.
-
Date submitted2008-10-24
-
Date accepted2008-12-06
-
Date published2009-12-11
Geological structure, characteristics of ores and genesis of ore occurrences in the Halvdanpiggen field (West Spitsbergen island)
- Authors:
- A. N. Sirotkin
- V. V. Khailov
- D. V. Nikitin
A new metallogenic zone was separated out in a central part of the archipelago Spitsbergen by the results of exploration work. It was shown an integral series of ore areas and fields in the limits of this zone, including the ore field Halvdanpiggen. This field integrates several non-uniformly scaled the ore occurrences, which present a great interest in regard to a material composition of the ore. They likewise produce an information for determination of genesis and outlooks of total metallogenic zone. The article contains data on geology, mineralogy and geochemistry of deposits; it is established their genesis, formation membership and time of origination.
-
Date submitted2008-10-23
-
Date accepted2008-12-05
-
Date published2009-12-11
Application of electrical prospecting in combination with seismic prospecting for the geological section prediction and search of hydrocarbon deposits
- Authors:
- V. A. Kuzin
- A. A. Korukhova
The possibility of application of electrical prospecting method SGN (sounding by field growing in the near-field zone) in combination with CDP seismic prospecting for sedimentary section investigations and hydrocarbon deposits prospecting is considered. The physical basis of the method application for hydrocarbon prospecting is the effect of higher resistance of seams, saturated by hydrocarbons. The effect is reflected in the curve of electromagnetic field growth ε(t). The procedures of field works, processing and interpretation of electrical prospecting data are presented.
-
Date submitted1958-03-16
-
Date accepted1958-05-23
-
Date published1958-05-09
НОВЫЙ МЕТОД ОПРОБОВАНИЯ ПО ТИПАМ РАЗРЕЗОВ
- Authors:
- Unknown
Предлагаемый метод опробования основан на закономерной зависимости между строением рудных залежей по мощности и содержанием ценного минерала. Основным объектом исследования явилось месторождение, на котором наиболее крупные рудные залежи генетически и пространственно связаны с первично хорошо расслоенным комплексом пород. Основной причиной образования расслоенного комплекса пород и рудных залежей является кристаллизационная дифференциация, которая заключалась, по-видимому, в следующем: а) движении кристаллизующегося магматического расплава; б) гравитации; в) большом скоплении элементов, дающих легколетучие соединения; г) увеличении вязкости кристаллизующегося расплава; д) неравномерном (последовательном сверху — вниз) охлаждении интрузивного тела; е) двух периодах кристаллизации расплава: первом — медленной кристаллизации главным образом лейкократовых минералов, втором — более быстрой кристаллизации всех остальных минералов магматического происхождения.
-
Date submitted1950-08-02
-
Date accepted1950-10-05
-
Date published1951-08-08
Some data clarifying the coefficient of variation
- Authors:
- N. V. Ivanov
The article sets the task of specifying the variation coefficient reflecting the distribution of a useful component in an ore deposit. The variation coefficient is a value characterizing the dispersion of the distribution of the material composition in the ore body of a particular deposit. As is known, attempts to use the variation coefficient to solve applied problems (for example, choosing the distances between samples and workings during sampling and exploration of deposits) were not very successful. The density of various workings and samples in this case significantly exceeded the accepted and justified practice. The unsuccessful use of the variation coefficient in solving the above problems is partly explained by the presence of a pattern in the spatial distribution of the material composition in the ore bodies of deposits, which is in conflict with the basic provisions of variation statistics. In addition, the determination of the value of the variation coefficient itself is inaccurate for two reasons: 1) incorrect use of factual material reflecting the nature of the mineral; 2) the influence of sampling error on the value of the coefficient of variation.