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Composition of salt
Published in M.L. Jeremic, Rock Mechanics in Salt Mining, 2020
The main characteristic of mineral heterogeneity of salt deposits of the Carpathian province is that potassium salts occur in association with magnesium salts but also in conjunction with sodium salt deposits. The multi-mineral development is of a complex nature and is usually located at the boundary of a sedimentary basin. The salt deposits are often intensely folded and partially brecciated. The development of potassium salts in a majority of cases occurs like a frame around the rock salt body, as illustrated in Figure 4.3.3. The understanding of these deposits has been established by geological mapping of underground mine workings on each mine level. The mapped data delineated the lateral extension and dip of individual salt facies and the relationship amongst them. Very complex heterogeneity of salt deposits interrupts continuous mining of the potash ore.
Development and application of optimum open-pit limits software for the combined mining of surface and underground
Published in Heping Xie, Yuehan Wang, Yaodong Jiang, Computer Applications in the Mineral Industries, 2020
Jianhong Chen, Jianxiong Li, Zhouquan Luo, Desheng Guo
The choice of the mining method and open pit limit for a specific mineral deposit depends on geological conditions. If the deposit changes much in geometry along the strike, especially if the change occurs at the end of the deposit, the stripping ratio will be too large when the whole deposit is mined by open-pit mining. In this case, it is more suitable to have the deposit mined by combined method, that is to say, the end part of the ore body should be mined by underground method. With the rise of metal prices and the cost reduction of underground mining, underground mining will have a potential advantage comparing with surface mining in extraction of deep-buried large mineral deposit.
Recent developments towards autonomous tunneling and mining machinery
Published in Daniele Peila, Giulia Viggiani, Tarcisio Celestino, Tunnels and Underground Cities: Engineering and Innovation meet Archaeology, Architecture and Art, 2020
T. Peinsitt, H. Haubmann, H. Kargl, C. Kary
As technology advances in many industries around the world, autonomous machinery has started to replace human labor force. For the last two decades, automation and robotics have been on the agenda of the mining and tunneling industry as well. Although automation has entirely and successfully been implemented in other industries, the mining and tunneling industry does not fully benefit from a complete automation solution so far. Therefore, advancements of mining and tunneling automation are emerging, especially for underground operations where increased efficiency and productivity and reduced risk of accidents are of an utmost concern. (Entezari, 2014)
A hybrid recognition model of microseismic signals for underground mining based on CNN and LSTM networks
Published in Geomatics, Natural Hazards and Risk, 2021
Yong Zhao, Haiyan Xu, Tianhong Yang, Shuhong Wang, Dongdong Sun
As shown in Figures 2 and 3:A typical MS signal is illustrated in Figure 2(a). This kind of signal is released by rock failure, showing slow signal attenuation and developed coda. The amplitude is lower than that of blasting signals and mechanical signals, and the dominant frequency is low, generally below 200 Hz. In addition, this kind of MS signal usually contains one peak.A typical blasting signal is shown in Figure 2(b). Since metal mines are mostly excavated and mined through blasting, many blasting signals are recorded in monitoring signals, with higher amplitude and wider dominant frequency range than MS signals. In addition, they have the characteristics of high amplitude, fast attenuation, and multiple peaks.A typical mechanical signal is shown in Figure 2(c). There are many mechanical equipment operations during mining in the underground mine, such as fans and drilling rigs, mine car transportation, truck transportation, and ore-drawing. Such signals have a long duration, slower attenuation, and wider dominant frequency range than MS signals. However, its developed coda is similar to MS signals. Moreover, because underground mechanical equipment produces many mechanical signals, and their signals are complex and diverse, it is difficult to distinguish them from MS signals.
Integrated optimisation of stope boundary and access layout for underground mining operations
Published in Mining Technology, 2019
Jie Hou, Chaoshui Xu, Peter Alan Dowd, Guoqing Li
The orebody block model is the fundamental input for optimisation. The mineralisation is delineated by geological interpretation and data from drill holes; the total volume is sub-divided into equal-sized blocks. The block size is a function of the scale on which the data are measured (drilling grid, other sampling configurations) and blocks are populated by estimated values of grades and other characteristics (e.g. geometallurgical and geotechnical variables). When economic and financial factors are incorporated, the block model is converted to an economic block model and the deposit can then be divided into valuable ore blocks and valueless waste blocks. Compared with open-pit operations, underground mining is more selective as mining can target ore blocks by access development while waste blocks may be left unmined. Ore dilution in this case only occurs largely when there is a mismatch between orebody and stope geometries.
Optimizing underground mine design with method-dependent precedences
Published in IISE Transactions, 2020
Peter Nesbitt, Levente Sipeki, Tulay Flamand, Alexandra M. Newman
Underground mining seeks to extract valuable minerals, which are not directly accessible from the surface. Deposits considered for underground extraction operations often extend thousands of meters below ground. Mine planners identify sections of rock that are profitable to mine (Rendu, 2014), and that subscribe to geotechnical principles of rock mechanics; subsequently, engineers design and operate mines to safely gain access to the ore body, and to extract valuable material. A single completed round of procedures such as drilling, blasting and removing rock, is called an activity. We consider two types of activities, broadly categorized as development and extraction. In actuality, activities can be more finely discretized into “unit operations,” e.g., mucking, scaling, ventilation, and backfilling (Hustrulid and Bullock, 2001); however, we aggregate activity categories, due to the scale of the deposit and the length of the time horizon. These activities consume resources and require costs or generate economic value. Development activities create infrastructure that provides access to the ore body. Declines constitute the primary access from the surface underground, whereas ramps are used to access different levels. Ore drives horizontally proceed through a specific level of the mine. With access, extraction activities free material and transport it to the surface for processing. We consider the ore body to be represented by panels, i.e., partitions subdivided into groups of stopes sharing the same access route; each panel is to be extracted using a specific method. Standard financial analysis procedures weight the cost of capital with respect to time.