scholarly journals Instability Assessment of Hanging Wall Rocks during Underground Mining of Iron Ores

Minerals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 858
Author(s):  
Oleg Bazaluk ◽  
Mykhailo Petlovanyi ◽  
Serhii Zubko ◽  
Vasyl Lozynskyi ◽  
Kateryna Sai

The paper presents the study of the deformation processes development in unstable rocks of the hanging wall during mining a thick steeply dipping ore deposit in the example of the Yuzhno-Belozerskyi deposit. In the studied field, there are problems of stability of hanging wall rocks, represented by low-resistant shale rocks that do not withstand significant outcrops in time. A decrease in stability is manifested in the form of failure of the hanging wall rocks into the stope. Based on a detailed study of the ore deposit geological structure and the performance of the stopes mining, according to the survey data, an area of the deposit has been identified where the ore failure and dilution reach 4%–8% with a maximum value of 12%. This also makes it possible to determine the most important averaged source data for performing physical modeling on equivalent materials. It has been determined that the deformation value of the hanging wall rocks with subsequent failure into the stope and ore mass deformation in the sloping bottom change exponentially with an increase in the depth of the stope location, and the dynamics of increasing rock deformations in the hanging wall is noticeably higher than in the sloping bottom of the stope. This reduces the quality of the mined ore and increases the probability of rock failure area propagation to the hanging wall drifts with their subsequent destruction. The results of physical modeling are characterised by acceptable reliability and are confirmed by a high similarity with the actual data on ore dilution with broken rocks during the stopes development. It has been found that during the formation of a steeply dipping outcrop of stopes with an area of 1200 m2, unstable rocks of the hanging wall are prone to failure of significant volumes. For successful mining and achieving stope element stability, it is recommended to optimise its parameters, the height, width and the value of a steeply dipping outcrop, as well as to preserve the ore pillar in the hanging wall until the ore is broken and drawn from the rest of the stope.

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Paweł KURZYDŁO ◽  
Witold PAWLOS

The Zechstein copper ore deposit located on the Foresudetic monocline has a complex geological structure both in lithological and mineralogical aspects. The significant variability in quantity and quality of minerals deposited in the ore bed is one of the factors determining the susceptibility of copper ore to beneficiation based on flotation, which is carried out in the KGHM Concentration Plant. Based on the algorithm developed, flotation experiments on a laboratory scale have been conducted to predict the upgrade rates under industrial conditions. This paper provides the results of the mineralogical examination of the flotation products performed by one of the KGHM Concentration process lines and compares the beneficiation of various copper sulphide minerals. The results of the laboratory tests have been compared with the results of sampling carried out simultaneously at the process line. A procedure has been proposed to develop equations defining the industrial upgradability curves for copper sulphide minerals under the KGHM Concentration Plant conditions.


2021 ◽  
Vol 15 (3) ◽  
pp. 405-420
Author(s):  
Bhanu Chander Balusa ◽  
Amit Kumar Gorai

In the last few decades, many underground mining methods were proposed for extractions of ores. The decision-making for selecting the most suitable mining method for a typical ore depost depnds on various intrinsic and extrinsic factors (intrinsic – dip, shape, thickness, depth, grade distribution, RMR (rock mass rating) and RSS (rock substance strength) of ore, hanging wall, footwall, and extrinsic – recovery, dilution, safety, productivity, flexibility, capital). The present study aims to develop a hierarchical Fuzzy-AHP (FAHP) model for choosing the most suitable underground mining method for an ore deposit. The structure of the proposed hierarchical FAHP model consists of five levels. The level-1 of the hierarchy defines two variables (intrinsic factors and extrinsic factors). These are further classified into quantitative or qualitative nature of variable (listed in level-2). The criteria, sub-criteria, and mining method variables are listed respectively in Level 3, Level 4, and Level 5. For each level of the hierarchy, a fuzzy pair-wise comparison matrices are developed using the corresponding levels’ listed variables. These matrices at each level are subsequently used to determine the local and global weights of each variable. The global weights are used for prioritizing the different mining methods. The proposed hierarchical FAHP model was validated by considering the field data of two different ore deposits in India. The results showed that the most appropriate mining method predicted from the decision-making model and the adopted mining method for extracting the ore deposit are same in two case studied mines.


2019 ◽  
Vol 28 (4) ◽  
pp. 706-716
Author(s):  
Mykhailo V. Petlovanyi ◽  
Vladislav V. Ruskykh

This paper is dedicated to research into the geological peculiarities, shape of the ore body and the occurrence of the host rocks in the hanging wall of the Pivdenno-Biloz- erske deposit , as well as their influence on the degrees and quality of high-grade iron ore extraction. It is noted that in the interval of 480 – 840 m depths, a decrease is observed in the stability of the natural and technogenic massif, which is caused by the increase in rock pressure with depth, the influence of blast- ing operations on the massif and the difference in geological conditions. This has led to the collapse of hanging wall rocks and backfill into the mined-out space of chambers in certain areas of the deposit, the dilution of the ore and deterioration of the operational state of the underground mine workings. Attention is focused on the causes and peculiarities of consequences of the collapse of the hanging wall rocks during ore mining, which reduce the technical and-economic indexes of the ore extraction from the chambers. A 3D-model of an ore deposit with complex structural framework has been developed, which makes it possible to visually observe in axonometric projection the geological peculiarities and the shape of the ore body. The parameters have been studied of mining chambers in the 640 – 740 m floor under different changing geological conditions of the ore deposit and hanging wall rocks occurrence – the northern, central and southern parts. The difference in the iron content in the mined ore relative to the initial iron content in the massif has been defined as an indicative criterion of the influence of changing conditions on the production quality. The reasons have been revealed which contribute to the collapse of the rocks and the subsequent decrease in the iron content of the mined ore in ore deposit areas dif- fering by their characteristics. It has been determined that within the central and half of the southern ore deposit parts with a length of 600 m, an anomalous geological zone is formed, the manifestation of which will be increased with the depth of mining. It was noted that within this zone, with the highest intensity and density of collapse of hanging wall rocks, the influence of decrease in the slope angle and change in the strike direction are of greatest priority, and such geological factors as a decrease in hardness, rock morphology, deposit thickness increase this influence significantly. To solve the problems of the hanging wall rocks’ stability, it is recommended to study the nature and direction of action of gravity forces on the stope chambers in the northern, central and southern parts, as well to search for scientific solutions in regard to changes in the geometric shapes of stope chambers and their spatial location, improving the order of reserves mining in terms of the ore deposit area, the rational order of breaking-out ore reserves in the chambers with changing mining and geological conditions of the fields’ development.


2020 ◽  
Vol 201 ◽  
pp. 01027
Author(s):  
Mykhailo Petlovanyi ◽  
Vladyslav Ruskykh ◽  
Serhii Zubko ◽  
Volodymyr Medianyk

Paper presents the research results of the relationship revealed between the mined ore dilution factors and the geological structure and properties of the hanging wall rocks. The research methodology is in the analysis of the structure and properties of the hanging wall rocks, the technological parameters of the stopes in contact with the host rocks, the processing of actual surveying data of the rockfall volumes and dilution factors, the construction of a 3D model of the mined floor with the stopes divided according to the sequence of mining. The peculiarities have been revealed of changing the geological structure along the strike of the ore deposit with a characteristic distinguished tendency to decreasing the hardness of hanging wall rocks, the angle of the ore deposit slope, increasing the deposit thickness and replacing the morphological composition of the rocks with the division into 3 characteristic differing areas. New patterns and empirical equations have been determined for changing the ore dilution value in the primary stopes depending on the type, hardness coefficient and the contact area of the hanging wall rocks with the inclined outcropping of the stopes. A multiple regression equation has been obtained of the relation between the primary stopes dilution with the rocks hardness within f = 11 – 15 and the contact area of the stopes with rocks 780 – 2010 m2. The regression model variability of 85.96% evidences its reliability and representativeness. The methodological approach proposed in the paper can be used to develop an improved methodology for predicting the mined ores dilution when mining the Pivdenno-Bilozirske field, supplemented by a more complete data set to increase reliability.


2013 ◽  
Vol 762 ◽  
pp. 261-265 ◽  
Author(s):  
Tanya I. Cherkashina ◽  
Igor Mazur ◽  
Sergey A. Aksenov

Numerical and physical simulation on model samples can provide data for various aspects of metal forming, without resorting to time-consuming and costly full-scale tests. This paper presents examples of modeling of the deformation of a slab with a liquid core. The use of soft reduction can enhance the homogeneity of the structure, which improves the quality of cast billets. Mathematical modeling is described here where the fluid layer is taken into account by the influence of boundary conditions in the crust in the form of ferrostatic pressure, which allows calculation of the intensity of deformation, total deformation and strain. It also provides a novel method for studying the process of soft reduction. It is based on a physical model of the slab consisting of a closed solid shell made of a calibrated lead shot and the Wood's alloy. To simulate the liquid molten metal, the interior of the shell is filled with gelatin. This approach can be applied to further studies on deformation processes and the penetration of deformation into complex metallic systems.


2014 ◽  
Vol 989-994 ◽  
pp. 1631-1634
Author(s):  
Ping Wang ◽  
Bin Wang

Product data is the source data of product lifecycle in manufacturing enterprise. The quality of product data largely determines the effect of the application of Engineering analysis, simulation assembly and CNC programming work and so on. In order to solve the problems of the existing product data quality, such as validation custom trival, lack of high efficiency and flexibility, etc. The validation method of product data quality (PDQ) based on class was proposed in NX software environment, the representation of validation rules classes of product data quality, validation rules customization and implementation of validation process were introduced in detail in this study. Finally, an application case was employed to verify the practicability and effectiveness of the proposed method.


Author(s):  
I. V. Sokolov ◽  
Y. G. Antipin ◽  
N. V. Gobov ◽  
I. V. Nikitin

Based on an analysis of the design principles and practice of underground mining of ore deposits, the most significant features, trends to develop and directions to enhance of underground geotechnology in the field of opening and preparation, mining systems, filling works and ore preparation have been established. The main signs of innovation - scientific research and implementation in production in order to obtain additional value, are highlighted. Various approaches to the development of innovative underground geotechnologies are shown and a methodology for their justification is formulated based on a systematic approach implemented in the framework of the concept of integrated development of mineral resources and on the principles of economic efficiency, industrial and environmental safety, completeness of subsoil development. The experience of the IM UB RAS on the development and implementation of innovative underground geotechnologies in the design and industrial operation of a number of ore deposits is given, which significantly increased the completeness and quality of ore extraction from the subsoil, increased labor productivity in sinking and stoping works, reduced capital and operating costs for ore mining and to utilize mining and processing waste in the mined-out space.


2020 ◽  
Vol 177 ◽  
pp. 02006
Author(s):  
Andrey Vedernikov ◽  
Pavel Zuev ◽  
Danila Grigoriev

Often in deposits developed by underground mining, the task is to control the state of the earth's surface within the mine field. And this problem is even more acute in the case of combined open-underground mining. The Goroblagodatskoe iron ore deposit has been developed by a combined method for more than 40 years. The article describes the methodology and results of applying the geophysical diagnostic method at a mining facility developed by a combined open-underground method - the spectral seismic profiling method (SSP). The application of this method is justified. This method has shown its sufficient efficiency in terms of time costs and sufficient reliability for local studies. The results of field and desk studies are obtained, an assessment of the nature of the object is given, which justifies the use of further measures for the safe development of the object.


Author(s):  
Agnieszka Gontaszewska ◽  
Andrezej Krainski

In paper an influence of waste dump “Chrobrów” on groundwater and tributary of the Bóbr river was described. This waste dump was installed in former gravel excavation. For first 10 years it had no leak stopper and sewage water could freely infiltrate. Geological structure of the waste dump subsoil is unfavourable because garbage are directly stored on gravels with high filtration coefficient which make migration of pollutants easy. At the moment the waste dump has a leak stopper made from bentonite composite but there are still polluted groundsunderneath. In this paper was analyzed data about ground- and surface water quality from years 1994 – 2004. It was found that the quality of groundwater deteriorated, especially in years 1999 and 2002. The most worsening was noted in case of chlorides, ammonia nitrogen, sodium and potassium. Unfortunately there is no data before 1994 so there is no information about hydrogeochemical background. Increased values of all groundwater components infirst period of investigation are results of exploitation in years 1984 – 1994, when waste dump had no leak stopper.But later deterioration of groundwater quality can not be explained in this way. It should be drawn a conclusion that the seal of waste dump bottom does not work correctly. It was found that there is no negative impact of waste dump on surface water what is caused by absence of hydraulic contact between river and groundwater on investigated area.


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