scholarly journals Reasonable coal pillar design and remote control mining technology for highwall residual coal resources

2019 ◽  
Vol 6 (4) ◽  
pp. 181817 ◽  
Author(s):  
Fangtian Wang ◽  
Cun Zhang
Keyword(s):  
Remote Control ◽  
Coal Pillar ◽  
Open Pit Mine ◽  
Open Pit ◽  
Recovery Ratio ◽  
Coal Resources ◽  
The Road ◽  
Highwall Mining ◽  
Geological Conditions ◽  
Residual Coal

Highwall mining (HWM) technology is an efficient method for exploiting residual coal resources in Chinese open-pit coal mines. However, on-site personnel and equipment can be damaged by the instability of the highwall mining residual coal pillars and subsidence of final end-walls. This paper considers the geological conditions of an open-pit mine in Shendong Coal Field (China) in order to prevent overlying rock fall accidents; the Mark-Bieniawski formula and the FLAC3D numerical simulation are used to analyse reasonable coal pillar widths outside and under the road, which were determined to be 1.7 m and 1.3 m, respectively. Using the EBH132 cantilever excavator for remote control mining, the field experiment shows that the recovery ratio of highwall residual coal resources was over 67%; hence, safety, efficiency and high recovery ratio of highwall mining were achieved for the residual coal resources of an open-pit mine.

scholarly journals Study of the Conditions for Construction of the Haulage Berm in the Deposit Ledger-Wall

2019 ◽  
Vol 105 ◽  
pp. 01034
Author(s):  
Svetlana Bakhaeva ◽  
Elena Chernykh
Keyword(s):  
Slope Angle ◽  
Open Pit ◽  
Factors Affecting ◽  
The Road ◽  
Road Base ◽  
Single Side ◽  
Geological Conditions ◽  
Shipping Cost ◽  
Shear Characteristics ◽  
Spoil Bank

To reduce transportation distance and shipping cost for rock haulage with a single-side development system, it is relevant to build roads on the spoil bank of the open-pit. The article reviews factors affecting stability of the spoil bank and the most common types of deformation. The backward calculation method for obtaining resistance to shear characteristics of the base rocks in contact with a road embankment has been described. Schemes for road constructions on the spoil bank of the open-pit have been considered. Mining and geometric simulation of the road base has been built. Zoning of the road base as per slope angle of the underlying rock and parameters of the haulage berm allow tracing rapidly axis of the technological and engineering roads for actual engineering and geological conditions. Besides, measures to reduce risk factors of landslides during construction of the haulage berm at deposit ledger-wall have been considered.

scholarly journals Study on the Rheological Failure Mechanism of Weakly Cemented Soft Rock Roadway during the Mining of Close-Distance Coal Seams: A Case Study

2020 ◽  
Vol 2020 ◽  
pp. 1-20
Author(s):  
Wenkai Ru ◽  
Shanchao Hu ◽  
Jianguo Ning ◽  
Jun Wang ◽  
Qingheng Gu ◽  
...  
Keyword(s):  
Coal Seam ◽  
Failure Mechanism ◽  
Coal Pillar ◽  
Soft Rock ◽  
Western China ◽  
Creep Failure ◽  
Mining Areas ◽  
Geological Conditions ◽  
Residual Coal ◽  
Close Distance

During the mining of the shallow-buried and close-distance multiple coal seam, the rheological failure of the surrounding weakly cemented soft rock of the roadway in the lower coal seam under the concentrated stress is very rare. However, the stress on the roof of the upper coal seam is transmitted down through the residual pillar, resulting in this situation. Taking the Gaojialiang coal mine which is located in the mining areas of western China as the research object, the failure mechanism of the roadway roof under the residual coal pillar in the shallow-buried and close-distance multiple seam is studied in combination with field monitoring and numerical simulation. Furthermore, suggestions on the roadway support under such geological conditions are proposed. The results show that the residual coal pillar in the working face of the lower coal seam gradually collapses during the mining of the shallow-buried and close-distance multiple coal seam. The concentrated stress transferred by the coal pillar increases further, which makes the roof stress of the lower coal seam roadway to increase continuously. In addition, the stress of the roadway roof also increases further due to the rotation of the broken rock above the goaf, and the peek region of stress moves to the nongoaf area. Combining the heavy concentrated stress and weakly cemented property, the shallow-buried surrounding rock shows rheological behavior and failure. Therefore, we must pay more attention on the creep failure of the roadway roof under the action of the residual coal pillar even in the shallow-buried coal seam.

scholarly journals The Sustainable Development of Aged Coal Mine Achieved by Recovering Pillar-Blocked Coal Resources

Energies ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3912
Author(s):  
Huadong Gao ◽  
Baifu An ◽  
Zhen Han ◽  
Yachao Guo ◽  
Zeyu Ruan ◽  
...  
Keyword(s):  
Coal Mine ◽  
Coal Pillar ◽  
Economic Benefits ◽  
Industrial Facilities ◽  
The Sustainable Development ◽  
Coal Resources ◽  
Coal Pillars ◽  
Social Environmental ◽  
Residual Coal ◽  
China’S Economy

China faces the problem of depletion of its coal resources, and a large number of mines are becoming aged mines. Demand for coal, however, still increases due to the growth of China’s economy. Energy shortage might restrict the sustainability of China’s national economy. As one contribution to a solution, this paper proposes the innovative exploitation method of solid backfill coal mining (SBCM) technology to exploit parts of pillar-blocked (residual coal pillar resources under industrial square, RCPRIS) that protect industrial facilities. Thus, blocked coal resources may be converted into mineable reserves that improve the recovery ratio of mine resources. Also, waste would be removed from the surface reducing hazards of environmental pollution. Based on the case of the Baishan Coal Mine in Anhui, China, numerical simulation is used to study the size of shaft-protecting coal pillars (SPCP) required at different backfill ratios. Results show that the disturbance to a shaft caused by exploitation decreases with the increase of the backfill ratio. When using SBCM to exploit RCPRIS under the condition of 80% backfill ratio, compared with the caving method, a lot of pillar-blocked coal resources would be freed. The life of Baishan Coal Mine would be prolonged, resulting in appreciable social, environmental, and economic benefits.

scholarly journals Mining Risks at Exploitation in Roşia Poieni Open Pit Mine, Romania

Mining Revue ◽  
2021 ◽  
Vol 27 (1) ◽  
pp. 1-11
Author(s):  
Mihaela Toderaş
Keyword(s):  
Financial Risk ◽  
Raw Materials ◽  
Open Pit Mine ◽  
Open Pit ◽  
Natural Phenomena ◽  
Work Area ◽  
Geological Conditions ◽  
Important Field ◽  
Potential Risks ◽  
Prevention Plan

Abstract The mining sector is a particularly important field that has the ability to support the economic development of a country by supplying various mineral products that are used as raw materials in other sectors of activity. When the depth at which a deposit is located and the geological conditions allow, the exploitation of useful mineral substances is realized through open-pit mine. The aim of this paper is to analyze the malfunctions that could occur and cause susceptible incidents and that could have consequences on staff safety and the environment. These malfunctions can have different causes: either an internal origin of the mining unit, or in natural phenomena. In this paper are identified and analyzed the potential mining risks that may occur in the Roşia Poieni open pit mine. The guidelines underlying the identification of these risks took into account three main principles: reducing risks for people, ensuring their security and at the same time limiting the risks on the property, respectively the financial risk for the mining unit. Acknowledge these risks, allows the delimitation of areas that are directly or indirectly exposed to potential risks and the establishment of specific measures for prevention, protection and security regarding the realized activities. Depending on the potential mining risks identified, we have made a hazard map that can be used to develop a risk prevention plan, taking into account the presence of several types of risks that may overlap in the same work area of the quarry.

scholarly journals Theoretical Analysis of Damaged Width & Instability Mechanism of Rib Pillar in Open-Pit Highwall Mining

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Rui Wang ◽  
Shuai Yan ◽  
Jianbiao Bai ◽  
Zhiguo Chang ◽  
Tianhao Zhao
Keyword(s):  
Failure Criterion ◽  
Failure Process ◽  
Economic Benefits ◽  
Open Pit ◽  
Instability Mechanism ◽  
Coal Seams ◽  
Mining Operations ◽  
Factors Affecting ◽  
Highwall Mining ◽  
Residual Coal

To improve the resources’ recovery ratio and the economic benefits of open-pit mines, the development of highwall mining is used to exploit residual coal. The design of rib pillar, formed by excavation and mining activities in intact coal seams, is crucial to the overall stability and safety of the highwall mining operations. This paper focuses on the damage caused to rib pillars by the large deformation, occurring with the application of highwall mining in an open-pit in China. A mechanical model was established to investigate the damaged width of colinear rib pillars based on Hoek–Brown and Mohr–Coulomb failure criterion. The equations for calculating the damaged width of the rib pillar were obtained, respectively, by combining the Hoek–Brown failure criterion with the Mohr–Coulomb failure criterion. The failure mechanism for the width of the rib pillar and the factors affecting the colinear rib pillar were analyzed in detail. The results show that the application of the Hoek–Brown criterion has a unique advantage in analyzing the damaged width of the colinear rib pillars, in open-pit highwall mining. The instability mechanism and failure process of the rib pillars are described in combination with the limiting equilibrium method and the ratio of the elastic zone’s width to the width of the entire rib pillar.

scholarly journals Updating Road Information in Open-Pit Mines Using Truck Trajectories

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Tian Fengliang ◽  
Sun Xiaoyu ◽  
Gu Xiaowei ◽  
Xin Fengyang ◽  
Ma Li
Keyword(s):  
Information Retrieval ◽  
Open Pit Mine ◽  
Open Pit ◽  
Trajectory Data ◽  
Open Pit Mines ◽  
Factors Affecting ◽  
The Road ◽  
Planning And Management ◽  
Effective Planning

Accurate road information is crucial for the effective planning and management of open-pit mines. However, the parameters related to the roads in open-pit mines change constantly, and their shapes are often complicated. These factors indicate the difficulties in updating road information in open-pit mines. This study reports a method for updating the road information in open-pit mines using the trajectories of trucks. The method employs an algorithm for compressing trajectory data, an algorithm for extracting new roads, and an algorithm for old-road classification. Data from the Fushun open-pit mine is used to validate this method, and our experiments show that it can identify more than 90% of new roads and the majority of disappearing roads. In addition, we analyze several factors affecting the results obtained using this approach and provide a detailed description of the limitations of this method. Overall, our findings indicate that this is a promising approach to road-information retrieval.

scholarly journals Study on Web Pillar Stability  in Open-Pit Highwall Mining

2021 ◽  
Author(s):  
Juyu Jiang ◽  
Zhuowei Zhang ◽  
Dong Wang ◽  
Laigui Wang ◽  
Xinping Han
Keyword(s):  
Ultimate Strength ◽  
Coal Pillar ◽  
Open Pit ◽  
Instability Criterion ◽  
Pillar Width ◽  
Mining Technology ◽  
Pillar Stability ◽  
Yield Zone ◽  
Highwall Mining ◽  
The Web

Abstract When highwall mining technology is applied to recover large amounts of residual coal left under the highwall of a big open-pit mine, reasonable coal pillar width is the premise for maintaining the stability of web pillars. By adopting the numerical simulation method, the characteristics of the abutment stress distributions in the web pillars under different slope angles and mining depths are studied, and the function of the stress distribution in the web pillar is established. The relationship between the abutment stress and the ultimate strength of the web pillar under different widths is also analyzed and used in combination with the failure characteristics of the pillar yield zone to explore the instability mechanism of the web pillar. The retaining widths of the web pillars are determined. Based on the modeling results, a mechanical bearing model of the web pillar is established, a cusp catastrophe model of pillar-overburden is constructed, and the formula for the web pillar instability criterion is obtained. By analyzing and calculating the ultimate strength of the web pillar, the formula for calculating the yield zone width at both sides of the pillar is achieved. Using the instability criterion of web pillars in highwall mining, a reasonable pillar width can be deduced theoretically, which provides significant guidance on the application of highwall mining technology.

scholarly journals Risk Assessment and Prevention of Surface Subsidence under Buildings by Cemented Paste Filling and Strip Mining Methods: A Case Study

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Sun Qiang ◽  
Zhou Nan ◽  
Song Weijian ◽  
Zhao Xu
Keyword(s):  
Surface Deformation ◽  
Surface Subsidence ◽  
Environmental Benefits ◽  
Strip Mining ◽  
Coal Resources ◽  
Industrial Sites ◽  
Coal Recovery ◽  
Geological Conditions ◽  
Continuous Mining ◽  
Residual Coal

Intensive and continuous mining of coal resources in China implies their gradual exhaustion, especially in the eastern regions. While some mines face closure, others have to extract residual coal resources under buildings, water bodies, and industrial sites. Thus, safe and efficient mining of the residual coal resources requires innovative techniques, which would account for the particular site’s geological conditions. In this study, two schemes of roadway mining with cemented paste backfilling (RMCPB) and strip mining are put forward. After analyzing the type, construction, and protection standard of the buildings, the probability integration method and the prediction model are used to assess the surface subsidence and deformation. The research results show that both schemes can control the surface deformation to a certain extent, but RMCPB combines the advantages of a high coal recovery rate and disposal of gangue waste. According to the surface subsidence predicted and measured data, the RMCPB method can effectively control the surface subsidence, deformation, and buildings’ safety. It also yields significant economic and environmental benefits.

Technological parameters and operation arrangement of stripping machines in chernogorksy open pit mine

2018 ◽  
pp. 22-35
Author(s):  
V. V. Agafonov ◽  
G. N. Shapovalenko ◽  
S. N. Radionov ◽  
V. Yu. Zalyadnov ◽  
N. S. Bikteeva
Keyword(s):  
Production Efficiency ◽  
Open Pit Mine ◽  
Open Pit ◽  
Open Pit Mining ◽  
Technological Parameters ◽  
Mining System ◽  
Geological Conditions ◽  
Production Output ◽  
The Cost ◽  
Stripping Efficiency

Many coal mines in Russia tend toward increasing their production output. Chernogorsky open pit mine, having expanded output by more than 30% for the last five years, is not exclusion. As output is increased whereas geological conditions complicate, technological parameters and production efficiency change. For example, in the open pit, percentage of overburden removal with direct dumping has greatly shrunk as against the truck-and-shovel system. In the meanwhile, the cost of stripping with the tuck-and-shovel system is much higher than in direct dumping by walking excavators. This article gives an analysis of technological parameters, open pit mining system parameters and stripping arrangement at the mine. The authors examine costs of stripping machinery maintenance and compare specific capacities of equipment in use. The modeling results on further increase in productivity of the open pit mine and in capacity of walking excavators are presented with the calculated optimized height of bench for stripping with direct dumping. The reserves available to increase stripping efficiency lie, in the authors’ opinion, in the system of resource allocation for equipment operability maintenance and personnel motivation.

Analysis of Efficiency of Drilling of Large-Diameter Wells With a Profiled Wing Bit / Badania Efektywności Wiercenia Studni Wielkośrednicowych Świdrem Skrawającym z Profilowanymi Skrzydłami

2012 ◽  
Vol 57 (2) ◽  
pp. 363-373
Author(s):  
Jan Macuda
Keyword(s):  
Average Rate ◽  
Large Diameter ◽  
Open Pit ◽  
Mechanical Parameters ◽  
Drilling Rate ◽  
Geological Conditions ◽  
Rock Drillability ◽  
Drilling Technology ◽  
Weight On Bit ◽  
Rotary Speed

Abstract In Poland all lignite mines are dewatered with the use of large-diameter wells. Drilling of such wells is inefficient owing to the presence of loose Quaternary and Tertiary material and considerable dewatering of rock mass within the open pit area. Difficult geological conditions significantly elongate the time in which large-diameter dewatering wells are drilled, and various drilling complications and break-downs related to the caving may occur. Obtaining higher drilling rates in large-diameter wells can be achieved only when new cutter bits designs are worked out and rock drillability tests performed for optimum mechanical parameters of drilling technology. Those tests were performed for a bit ø 1.16 m in separated macroscopically homogeneous layers of similar drillability. Depending on the designed thickness of the drilled layer, there were determined measurement sections from 0.2 to 1.0 m long, and each of the sections was drilled at constant rotary speed and weight on bit values. Prior to drillability tests, accounting for the technical characteristic of the rig and strength of the string and the cutter bit, there were established limitations for mechanical parameters of drilling technology: P ∈ (Pmin; Pmax) n ∈ (nmin; nmax) where: Pmin; Pmax - lowest and highest values of weight on bit, nmin; nmax - lowest and highest values of rotary speed of bit, For finding the dependence of the rate of penetration on weight on bit and rotary speed of bit various regression models have been analyzed. The most satisfactory results were obtained for the exponential model illustrating the influence of weight on bit and rotary speed of bit on drilling rate. The regression coefficients and statistical parameters prove the good fit of the model to measurement data, presented in tables 4-6. The average drilling rate for a cutter bit with profiled wings has been described with the form: Vśr= Z ·Pa· nb where: Vśr- average drilling rate, Z - drillability coefficient, P - weight on bit, n - rotary speed of bit, a - coefficient of influence of weight on bit on drilling rate, b - coefficient of influence of rotary speed of bit on drilling rate. Industrial tests were performed for assessing the efficiency of drilling of large-diameter wells with a cutter bit having profiled wings ø 1.16 m according to elaborated model of average rate of drilling. The obtained values of average rate of drilling during industrial tests ranged from 8.33×10-4 to 1.94×10-3 m/s and were higher than the ones obtained so far, i.e. from 181.21 to 262.11%.

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