Research results on application of semi-level induced caving with lateral loading in ore body Borska Reka (original) (raw)
Related papers
Borska reka' ore body, the future of the exploitation in Bor mine
2012
The most orebodies in Bor copper mine have been excavated during the more then a hundred year period of exploitation, and a part in a final stage of excavation. For these reasons, as long as thirty year of work on analysis and consideration possibilities for exploitation one of the largest ore bodies in Bor copper ore deposit. That is "Borska Reka" orebody. "Borska Reka" copper ore deposit dip in great depth and above the ore body there are part of the town, as well as transportation object essential for the region located. Analyses of the proposed methods applicable for this ore body are presented in this paper.
Management of the processes of flow of rock mass at underground mining in sublevel caving system
The paper offers an underground geotechnology for thick and thin coal beds based on the control of the pre-broken coal movement in terms of the force-feed extraction with using a re-designed powered roof support. One of directions in application of self-caving are technologies of mining of powerful flat and steep coals with using of powered supports, providing release of coal from roofs or interlayers. The following blast-free treatment of the roof-adjacent and interlayer coal are proposed and validated: vibrosesimic treatment with using veibroseis source installed in a subdrift; or a directional hydraulic fracturing through holes drilled from subdrifts. The mathematical model has been developed on the base of the Discrete Element Method (DEM) for the numerical simulation of gravitation movement of granular materials. The two-dimensional problem about sublevel coal caving in thick beds is studied, and the effect of the order exerted by opening the roof support outlets on the coal ex...
Raise Caving—A Hybrid Mining Method Addressing Current Deep Cave Mining Challenges
Bhm Berg- Und Hüttenmännische Monatshefte, 2022
Cave mining progresses to depths exceeding 1000 m and ore bodies situated in competent and strong rock masses are nowadays extracted by different cave mining methods. Widely applied caving methods in massive deposits are block and panel caving, inclined caving, and sublevel caving. All caving methods have in common that rock mass caves during extraction of an ore body in a controlled way. As a result, regional stress changes occur, considerable abutment stresses form, and large-scale subsidence and significant seismic energy releases occur. Experience shows that these rock mechanics effects become especially critical at great depths, where primary stress magnitudes reach and exceed rock mass strength, as well as in strong competent rock masses, which require large footprints to enable continuous caving. The presented raise caving method addresses previously mentioned rock mechanics issues. Initially, de-stressing slots are developed from raises with a minimum amount of pre-development. Substantial pillars separate neighboring slots in order to control stress magnitudes and seismicity near slots. The slots provide a stress shadow for production infrastructure so that large-scale mineral extraction can take place in de-stressed ground. As mining progresses, pillars are extracted and hanging wall is allowed to cave. Results of a pre-study conducted together with LKAB have highlighted advantages of raise caving from a rock mechanics, safety, and cost point of view.
Graduation Thesis Study, 2020
Mechanical excavation is the most widely used method to remove both overburden material and ore at surface mining activities. In spite of the direct excavation of these materials by heavy duty machines is rarely possible, blasting before excavation is commonly applied. The main purpose of blasting process is to disperse the planned amount of suitably fragmented material from the rock mass to haulage. Thus the huge rock masses which are not possible to dig and transport by duty machines are suited to diggable and transportable conditions by blasting application. Therefore the most important aim of bench blasting applications at surface mining is to provide suitable material for digging. There is no doubt that a good fragmentation provides the economy in size reduction (milling) during mineral beneficiation process as well as the possibility to optimize digging and transporting costs. In general, blasting operations aim two major outcomes; to obtain desired fragmentation and blasting cost. To obtain the most suitable blasting design for the results is only possible by trial and error method. Such that a blasting round design is primarily done by theoretical study and it is applied in practice. (JAMNİA, 2015
2018
Editor’s Note I n preparation for this issue of our newsletter, we have introduced a new strategy to attract articles of interest to our readership. Members of ARMA Publications Committee were asked to personally solicit articles from leading rock mechanics specialists on the newest theoretical, numerical, and applied research. For this first issue of the newsletter in which this plan is implemented, we have received one article by Haiying Huang, a member of our Committee, reporting results of her research in advanced modeling. We also received four other articles from rock mechanics specialists on new advances in their field of study. Because of space limitations, we decided to publish three of the articles in this issue, and the other two in the following one.
Mining operations and geotechnical issues in deep hard rock mining – case of Boukhadra iron mine
Geomatics, Landmanagement and Landscape
Underground mining operations are a very problematic task, especially in poor geotechnical conditions. The right choice of excavation and support techniques leads to adequate and secure mining operations. This should ensure the overall stability of the underground mine with the best productivity and stability performance. In this paper, an empirical model for obtaining support systems for underground galleries was applied. Then, a numerical model for the evaluation of the performance of support measures for rock masses in the Boukhadra iron mine was introduced. Extensive field and laboratory tests were performed to obtain geological, geotechnical, and mechanical data on the entire geologic formations of the (1105 m) level. The performance of the design is supported by the selection of a common support plan between RMR, Q, and UBC systems for each geotechnical unit. Therefore, the rock masses classification based on the geo-mechanical model has determined the suitable support systems. The finite element model (FEM) was used for the analysis of rock mass behaviour, displacements, stress, and plastic point distribution. The results permit the optimization of the plastic zone thickness around the gallery. The outcomes of this study could improve the stability of the mine by choosing the right direction of excavation in consideration to the direction of the discontinuity planes. In order to choose between the current and the recommended mining operations, an equivalent calculation sequence was verified. Our study demonstrated that the consideration of discontinuity sets in the orientation of excavation highly improves the mining conditions with or without support.
Numerical Simulation of Independent Advance of Ore Breaking in the Non-pillar Sublevel Caving Method
Journal of China University of Mining and Technology, 2007
The mechanism of stress generation and propagation by detonation loading in five separate independent advance of ore breaking patterns is discussed in the paper. An elastic numerical model was developed using AN-SYS/LS-DYNA 3D Nonlinear Dynamic Finite Element Software. In this package ANSYS is the preprocessor and LS-DYNA is the postprocessor. Numerical models in the paper to actual were 1:10 and the element mesh was dissected in scanning mode utilizing the symmetry characteristics of the numerical model. Five different advance rates were studied. Parameters, such as the time required to maximum stress, the action time of the available stress, the maximum velocity of the nodes, the stress penetration time, the magnitude of the stress peak and the time duration for high stress were numerically simulated. The 2.2 m advance appeared optimum from an analysis of the simulation results. The results from numerical simulation have been validated by tests with physical models.
Methodology for optimization of coefficient for ore recovery in sublevel caving mining method
Podzemni radovi, 2017
Ore recovery and ore dilution have an important role for efficient operation of a mine. With each increase in percentage of ore dilution and reduced ore recovery there is negative impact on the economic value of the ore reserves. These parameters are mainly controlled with quality mining project and in situ analysis. The primary goal of this science paper is to present the methodology for optimization of coefficient for ore recovery and ore dilution in sublevel caving mining method. The optimization will be carried out through economic parameters, ie by calculating the net present value (NPV).
Applicability of the shortwall mining methods in Rembas mine pits
In the Rembas mine pits, the coal exploitation lasts for more than one century. During this period, most of coal reserves have been mined, so there is a need for introduction the new and modern technical solutions, which will enable rationalization of exploitation, higher productivity, safety on operations and better operation conditions with lower investments. In the Rembas mine pits for coal exploitation, the low-productive pillar mining methods are used. During the eighties of the last century in some pits, the mechanized longwall mining method was applied, but the expensive equipment and complex naturalgeological conditions in the area Resava-Moravian coal basin restrict application of this metod. Bad financial situation, as well as the increasingly difficult operation conditions of exploitation, indicate a need to apply some of the methods which would be technically justified, and whose cost of exploitation would be proportional to the possibilities of mine. In this paper, the possibilities for application the shortwall mining methods are considered with their advantages compared to the previously applied mining methods in the Rembas mine.
Numerical Simulations of Caved Rock Mass Behaviour at the Kiruna Mine, Preliminary Study.
scansims.org
The present paper describes numerical simulations performed on the caved rock mass behaviour at the Kiruna Mine, where a huge iron lens, 4-5 km long, 80-100 m thick and dipping at 60 degrees, is extracted by sublevel caving. The rock located above the ore, also called hangingwall, fractures and eventually caves. While the fracture zone extends up to several hundreds of meters from the mine, the caving zone forms just at the vertical of the production area. In order to understand how and how long fractures build up in the hangingwall, pressures exerted by the caved rock onto the mine's walls must first be estimated.