Assessment of the extent of man-induced transformation of a subsoil block in upward mining using ore and host rock caving

2021 ◽  
pp. 113-118
Author(s):  
A.M. Mazhitov
Keyword(s):  
Rock Mass ◽  
Host Rock ◽  
Stress And Strain ◽  
Mining System ◽  
Ore Body ◽  
Ore Bodies ◽  
Ore Grades ◽  
The Stability ◽  
Host Rocks ◽  
Upward Mining

The study provides a geomechanical assessment of the man-induced transformation of the 1st block at the Kamaganskoye deposit when the mining system is changed to sub-level caving of the ore and host rocks with no possibility of changing the order of reserve extraction. The relevance of the research results from detailed exploration activities that revealed changes in the ore body boundaries and a decrease in the ore grades. The possibility of partial mining of blocks in ore bodies No. 16 and 17 using the ore and host rock caving system has been assessed and the possibility of retaining the upward mining sequence has been established. The sequence of room mining is defined taking into account the changes in the ore body boundaries. The paper presents the results of assessing the stability of the undermined masses of ore bodies No. 16 and 17, as well as the stress-andstrain state of the rock mass at the assumed sequence of room mining. The results of mathematical modeling of the rock mass stress-and-strain state during room mining using the ore and host rocks caving system proved the technical feasibility of this solution.

scholarly journals MODERNIZATION OF THE MINING SYSTEM OF SMALL DEPOSITS OF RICH COPPER PYRITE ORES

2020 ◽  
Vol 12 (3) ◽  
pp. 444-453
Author(s):  
Igor SOKOLOV ◽  
◽  
Yury ANTIPIN ◽  
Artem ROZHKOV ◽  
◽  
...  
Keyword(s):  
Mathematical Modeling ◽  
Rock Mass ◽  
Average Length ◽  
Thickness Variation ◽  
Chamber System ◽  
Mining Operations ◽  
Mining System ◽  
Ore Body ◽  
Experimental Block ◽  
Sublevel Caving

The purpose work. Substantiation and selection of a safe and effective option of mining technology of the experimental block in the pilot industrial mining of the Skalistoe deposit. Method of research. Analysis and synthesis of project solutions, experience in mining inclined low-thickness ore bodies, economic and mathematical modeling and optimization of the parameters of options mining systems in the conditions of the experimental block. Results of research. As a result of research it was established: - the sublevel caving mining system with the parameters adopted in the project does not guarantee the completeness of the extraction of reserves and the effectiveness of mining operations. Project indicators of extraction by sublevel caving technology with frontal ore drawing are overestimated and difficult to achieve in these geological and technical conditions (combination of low thickness and angle of ore body); project scheme for the delivery and transportation of rock mass seems impractical due to the significant volume of heading workings and increased transportation costs; - eight technically rational options of various mining systems were constructed, most relevant to the geological and technical conditions of the deposit. Five variants of the sublevel chamber system and pillar caving, a project variant of sublevel caving technology with frontal ore drawing and two options flat-back cut-and-fill system were considered; - for mining the Skalistoe deposit, according to the results of economic and mathematical modeling, optimal by the criterion of profit per 1 ton of balance reserves of ore is a option of the technology of chamber extraction with dual chambers, frontal drawing of ore by remote-controlled load-haul-dump machine and subsequent pillars caving, as having the greatest profit; - the calculations justified stable spans of dual chambers (25.3 m) and the width of panel pillars (3 m). With an allowable span of 25.3 m, the roof of the dual chambers will be stable with a safety factor of 1.41, and a panel pillar with a width of 3 m has a sufficient margin of safety (more than 1.6) in the whole range of ore body thickness variation; - the proposed scheme of delivery and transportation of rock mass, which allows to reduce the volume of tunnel works by 26% and the average length of transportation by 10-15% compared with the project. Findings. Developed in the process of modernization the technology sublevel chamber system with double-chamber, compared with the project technology, it is possible to significantly increase the efficiency of mining of the low thickness deposit of rich ores Skalistoe by reducing the specific volume of preparatory-rifled work by 34%, the cost of mined ore by 12%, losses and ore dilution – by 2 and 2.9 times, respectively.

scholarly journals Numerical Simulation of Fluid-Solid Coupling in Surrounding Rock for River Stope Mining

2020 ◽  
Vol 2020 ◽  
pp. 1-11 ◽  
Author(s):  
Haiping Yuan ◽  
Chenghao Chen ◽  
Zhongming He ◽  
Yixian Wang
Keyword(s):  
Rock Mass ◽  
Mining Area ◽  
Calculation Model ◽  
Rock Bridge ◽  
The Road ◽  
Ore Body ◽  
Safety And Reliability ◽  
Mining Disturbance ◽  
The Stability ◽  
Seepage Channel

Mining disturbance will induce further weakening of faults and rock bridges, improve rock mass permeability and, in serious cases, conduct surface rivers to cause disasters. A numerical calculation model of river-fault in the mining area is established. Based on the fluid-solid coupling theory of rock mass, the influence of mining disturbance on the development and evolution process of rock bridge rupture and river-fault-stope potential seepage channel is simulated and calculated. Research studies show that under the disturbance of ore body mining, it is possible to form a channel from the river to fault to seepage and drainage in the stope. The disturbance of ore body mining has no great adverse effect on the stability of the rock mass at the top of F2 fault. The rock mass damage caused by mining is only distributed in local areas, and the rock bridge between the river, fault, and stope is not completely connected. The fracture of mining rock mass leads to the increase in permeability of rock mass, and seepage tends to spread in the direction of the fault, but there is no obvious through drainage channel from surface water to the stope. The results of research provide technical guidance for the mine to use the filling mining method after the river does not change the road safety and reliability certification and can also provide reference for similar mines.

scholarly journals Geomechanics substantiation of pillars development parameters in case of combined mining the contiguous steep ore bodies

2021 ◽  
Vol 15 (1) ◽  
pp. 50-58
Author(s):  
Daulet Takhanov ◽  
Berikbol Muratuly ◽  
Zhuldyz Rashid ◽  
Adilzhan Kydrashov
Keyword(s):  
Rock Mass ◽  
Numerical Modelling ◽  
Seismic Survey ◽  
Geological Strength Index ◽  
Rock Fracturing ◽  
Efficient Technology ◽  
Field Methods ◽  
Rock Pillar ◽  
Ore Body ◽  
Ore Bodies

Purpose. Determining the actual dimensions of the protecting and crown pillars of ore bodies by seismic survey and assessing the possibility of rock mass collapse and fracturing at the lower levels of the Zhairemskoye field. Methods. An integrated approach is used, which involves the analysis of complete ore bodies development during the combined mining. To determine the geological strength index (GSI) and rock mass rating (RMR), the mass structure is studied, as well as the survey is executed of rock fracturing on the contours of mine workings at levels of +288, +240, +192, +144 m. In addition, the physical and mechanical properties of rocks are refined using the RocLab software. Using the numerical modelling of the self-caving process, when mining the protecting and crown pillars, the processed results of numerical modelling are analysed and the possible zones of the mass deformation are assessed based on the Phase2 software. Findings. It has been determined that during the mining of ore bodies 4 and 6, protecting pillars between the quarry and the underground mine, crown pillars between the levels up to the level of +144 m, the rock displacements are possible along glide surfaces. It has been revealed that the haulage workings of levels +240 and +192 m fall into the zone of possible displacements influence, and the rock pillar between ore bodies 4 and 6 will be exposed to inelastic deformations during the mining of crown pillars to the level of +144 m. It has been found that after the crown pillar development between the levels of +240 and +192 m for ore body 6, the rock pillar destructions are possible between ore bodies 4 and 6, since during the modelling, displacements of more than 2 mm are observed. In this case, the destruction processes are possible in the rock pillar upper part. Originality.A geomechanical assessment of the rocks tendency to caving is given and problem areas of stability during the mining of ore bodies 4 and 6 in the Zhairemskoye field are identified. Practical implications. The stable parameters of protecting and crown pillars have been substantiated, which is an important aspect in the design/efficient technology of mining the contiguous ore bodies. Keywords: engineering seismic, ore body, pillar, level, iron, manganese

ANALISIS KESTABILAN LERENG DINDING AKHIR DI PIT BARATLAUT PADA PENAMBANGAN BATUBARA DI PT. PUTERA BARA MITRA , KECAMATAN MENTEWE, KALIMANTAN SELATAN

KURVATEK ◽  
2018 ◽  
Vol 3 (1) ◽  
pp. 21-34
Author(s):  
Untung Wahyudi ◽  
Excelsior T P ◽  
Luthfi Wahyudi
Keyword(s):  
Slope Stability ◽  
Mining Operation ◽  
Subsurface Water ◽  
Mining System ◽  
Mine Site ◽  
Analysis And Design ◽  
The Stability ◽  
End Wall ◽  
Wall Slope ◽  
Mining Slope

PT. Putera Bara Mitra used open mining system for mining operation, Yet the completion of study on the end wall slope stability that  undertaken by geotechnical PT. Putera Bara Mitra in Northwest Pit and the occured a failure in the low wall on the 1st June 2012 led to the need for analysis and design the overall slope at the mine site. To analyze and design the overall slope, used value of the recommended minimum safety. The value was based on company for single slope SF ≥ 1.2 and SF ≥ 1.3 for overall slope. The calculation used Bichop method with the help of software slide v 5.0. Geometry improvements was done at the low slopes that originally single wall with a 30 m bench height and a slope 70° with SF = 0.781, into 4 levels with SF = 1.305. The analysis explained the factors that affect the stability of the low wall included the mining slope geometry, unfavorable drainase system, material stockpiles and seismicity factors. It was necessary to do prevention efforts to maintain the stability of the slope included the redesign to slope geometry, handling surface and subsurface water in a way to control slopes draining groundwater, vegetation stabilization using and monitoring slope using Total Station with Prism and Crackmeter to determine the movement of cracks visible on the surface. 

scholarly journals Magma Mixing Genesis of the Mafic Enclaves in the Qingshanbao Complex of Longshou Mountain, China: Evidence from Petrology, Geochemistry, and Zircon Chronology

Minerals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 195 ◽  
Author(s):  
Wenheng Liu ◽  
Xiaodong Liu ◽  
Jiayong Pan ◽  
Kaixing Wang ◽  
Gang Wang ◽  
...  
Keyword(s):  
Host Rock ◽  
Inductively Coupled Plasma ◽  
Magma Mixing ◽  
Coarse Grained ◽  
Calc Alkaline ◽  
Quartz Crystals ◽  
Alkaline Rocks ◽  
Mafic Enclaves ◽  
Normal Zoning ◽  
Host Rocks

The Qingshanbao complex, part of the uranium metallogenic belt of the Longshou-Qilian mountains, is located in the center of the Longshou Mountain next to the Jiling complex that hosts a number of U deposits. However, little research has been conducted in this area. In order to investigate the origin and formation of mafic enclaves observed in the Qingshanbao body and the implications for magmatic-tectonic dynamics, we systematically studied the mineralogy, petrography, and geochemistry of these enclaves. Our results showed that the enclaves contain plagioclase enwrapped by early dark minerals. These enclaves also showed round quartz crystals and acicular apatite in association with the plagioclase. Electron probe analyses showed that the plagioclase in the host rocks (such as K-feldspar granite, adamellite, granodiorite, etc.) show normal zoning, while the plagioclase in the mafic enclaves has a discontinuous rim composition and shows instances of reverse zoning. Major elemental geochemistry revealed that the mafic enclaves belong to the calc-alkaline rocks that are rich in titanium, iron, aluminum, and depleted in silica, while the host rocks are calc-alkaline to alkaline rocks with enrichment in silica. On Harker diagrams, SiO2 contents are negatively correlated with all major oxides but K2O. Both the mafic enclaves and host rock are rich in large ion lithophile elements such as Rb and K, as well as elements such as La, Nd, and Sm, and relatively poor in high field strength elements such as Nb, Ta, P, Ti, and U. Element ratios of Nb/La, Rb/Sr, and Nb/Ta indicate that the mafic enclaves were formed by the mixing of mafic and felsic magma. In terms of rare earth elements, both the mafic enclaves and the host rock show right-inclined trends with similar weak to medium degrees of negative Eu anomaly and with no obvious Ce anomaly. Zircon LA-ICP-MS (Laser ablation inductively coupled plasma mass spectrometry) U-Pb concordant ages of the mafic enclaves and host rock were determined to be 431.8 5.2 Ma (MSWD (mean standard weighted deviation)= 1.5, n = 14) and 432.8 4.2 Ma (MSWD = 1.7, n = 16), respectively, consistent with that for the zircon U-Pb ages of the granite and medium-coarse grained K-feldspar granites of the Qingshanbao complex. The estimated ages coincide with the timing of the late Caledonian collision of the Alashan Block. This comprehensive analysis allowed us to conclude that the mafic enclaves in the Qingshanbao complex were formed by the mixing of crust-mantle magma with mantle-derived magma due to underplating, which caused partial melting of the ancient basement crust during the collisional orogenesis between the Alashan Block and Qilian rock mass in the early Silurian Period.

scholarly journals Study on the Deformation Mechanism of Soft Rock Roadway under Blasting Disturbance in Baoguo Iron Mine

2018 ◽  
Vol 2018 ◽  
pp. 1-12
Author(s):  
Hong-di Jing ◽  
Yuan-hui Li ◽  
Kun-meng Li
Keyword(s):  
Rock Mass ◽  
Deformation Mechanism ◽  
Soft Rock ◽  
Deformation Monitoring ◽  
Underground Mines ◽  
Blasting Vibration ◽  
Iron Mine ◽  
The Stability ◽  
Soft Rock Roadway ◽  
Rock Roadway

In order to study the deformation mechanism of soft rock roadway in underground mines, it is necessary not only to study the influence of the dynamic disturbance caused by the cyclic mining blasting vibration on the stability of the soft rock roadway but also to study the degradation of the roadway surrounding rock itself and other factors. The paper presented a synthetic research system to investigate the factors that influence roadway rock structure deterioration in Baoguo Iron Mine. Firstly, the stability of rock mass was analyzed from the perspective of the physical and structural characteristics of the rock mass. Afterwards, according to monitoring data of mining blasting vibration, a suitable safety blasting prediction model for Baoguo Iron Mine was determined. And then, combining the results of mining blasting vibration monitoring and deformation monitoring, the effect of cyclic mining blasting on the stability of the soft rock roadway was obtained. By systematically studying the intrinsic factors of rock quality degradation and external environmental disturbances and their interactions, this paper comprehensively explores the deformation mechanism of soft rock roadway and provides the support for fundamentally solving the large deformation problems of soft rock roadway in underground mines.

Hydro-Mechanical Coupled Analysis of the Stability of Surrounding Rock Mass of Underground Water-Sealed Oil Storage

2013 ◽  
Vol 405-408 ◽  
pp. 402-405 ◽  
Author(s):  
Yun Jie Zhang ◽  
Tao Xu ◽  
Qiang Xu ◽  
Lin Bu
Keyword(s):  
Rock Mass ◽  
Underground Water ◽  
Surrounding Rock ◽  
Comsol Multiphysics ◽  
Coupled Analysis ◽  
Coupling Theory ◽  
Oil Storage ◽  
Stability Of Surrounding Rock ◽  
Straight Wall ◽  
The Stability

Based on the fluid-solid coupling theory, we study the stability of surrounding rock mass around underground oil storage in Huangdao, Shandong province, analyze the stress of the surrounding rock mass around three chambers and the displacement change of several key monitoring points after excavation and evaluate the stability of surrounding rock mass using COMSOL Multiphysics software. Research results show that the stress at both sides of the straight wall of cavern increases, especially obvious stress concentration forms at the corners of the cavern, and the surrounding rock mass moves towards the cavern after excavation. The stress and displacement of the surrounding rock mass will increase accordingly after setting the water curtains, but the change does not have a substantive impact on the stability of surrounding rock mass.

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