CHINA MINE ENGINEERING

Abstract:To comprehensively evaluate the stability of open-pit mine slopes during the production process, an analytical model is established based on the Analytic Hierarchy Process and fuzzy mathematics theory to evaluate the stability of slopes. Fully consider the engineering geology, geometric conditions, hydrology and meteorology, and external loads that affect the stability of open-pit mine slopes, and establish a two-level evaluation index system consisting of 14 sub indicators. Based on the trend characteristics of the impact of different sub indicators on the stability of open-pit mine slopes, establish a membership fuzzy matrix and weight set for the corresponding indicators; Construct a fuzzy comprehensive evaluation system based on two-level analytic hierarchy process and evaluate the stability of open-pit mine slopes. Research has shown that the stability evaluation method for open-pit mine slopes based on Analytic Hierarchy Process and Fuzzy Mathematics theory is simple and practical in calculation, and the evaluation results are in good agreement with the actual situation. It can provide guidance and assistance for the stability evaluation of open-pit mine slopes.

Abstract:Based on the occurrence characteristics of goaf in mines, three-dimensional laser scanning and transient electromagnetic method were respectively used to detect the visible and invisible goafs, and fine three-dimensional models of goaf groups were obtained. On this basis, a three-dimensional numerical calculation model was established to carry out numerical simulation of goaf stability. Analyzed the distribution of maximum principal stress, minimum principal stress, plastic zone, and stress intensity ratio after excavation in the goaf of Section 6, as well as the displacement variation of each monitoring point with the calculation time step. The results show that the maximum principal stress of the rock mass in Section 6 is -0.25~-3.9MPa, and the minimum principal stress is 0.29~-0.50MPa. The stress intensity ratio in the pillar between the goaf and the adit is ≥1.64. The overall stability of the adit is good, while the stability of the goaf is relatively poor. The research methods and achievements provide useful references for the detection and treatment of hidden goaf under similar conditions.

Abstract:In this paper, ShapeMetrix 3D system is used to make statistics on the joint data of the measurement points in the middle section of vein 12 of Jinxing Gold mine. Combined with the indoor rock mechanics experiment, the quality of underground rock mass is classified based on Q system and RMR classification. It is concluded that most of the surrounding rocks in the middle section of vein 12 of Jinxing Gold mine belong to class Ⅱ~ Ⅲ rock mass. Through theoretical calculation, it is concluded that the roof and two walls of underground roadway can be supported by pipe joint bolt and metal mesh, and the mesh of bolt is 2m×2m. Bolt length 2.2m, bolt spacing 1.5m.

Abstract:Jiaojia Gold Mine adopts the mechanized production mode of drilling trolley and anchor trolley supporting large trackless shovel transport equipment, it is found that the shotcrete quality and early strength are low in the shotcrete supporting link of stope approach, as a result, the matching degree between shotcrete operation and drilling and shoveling is reduced, continuous operation is not possible.Based on this background, mine technicians study the slurry spray, through raw material testing, empirical formula calculation, experimental ratio adjustment, field verification, finally determine the shotcrete slurry ratio, the 2-hour compressive strength of the gunite reaches 1MPa, to achieve the early strength of shotcrete to achieve the effect of safety support, then it provides support for the optimization of production links such as drilling and shoveling, to realize the purpose of safe and efficient continuous construction operation in mines.

Abstract:Aiming at the large deformation of the deep roadway in Xingdong Mine, which often shows more obvious asymmetric characteristics, asymmetric support technology along the air excavation roadway is proposed. Numerical simulation software was used to establish a calculation model in the 11216 working face freight lane of Xingdong Mine to verify the support effect of different support methods, such as different anchor arrangement, top anchor quantity, gang anchor quantity, solid coal gang arrangement, and coal pillar gang anchor arrangement, so as to find the optimal support scheme. And according to the corresponding support program in the 11216 working face transporting material roadway for industrial test. The results show that in the test tunnel, the amount of roof subsidence can be controlled within the safe range during the mining process, and the deformation of the two gangs is also effectively controlled.

Abstract:With the development of Deep Learning in the field of Artificial Intelligence, BP neural network algorithms are also widely used in research work in various industries, and gas emission prediction is a multi-dimensional, nonlinear, small-sample prediction problem. Aiming at the problem of mine gas emission prediction, this paper establishes a PSO-BP neural network algorithm model, collects 20 sets of sample data from some coal mine in Shanxi Province from 2017 to 2023, and uses 15 sets of them as training sets. Five sets of sample data were used for regression prediction of gas emission, and finally compared the mean absolute error, mean square error, root mean square error, mean absolute percentage error, and prediction accuracy of the PSO-BP neural network algorithm and the BP neural network algorithm. The results show that the gas emission prediction model based on the PSO-BP neural network algorithm has higher accuracy, can meet the actual needs of mine safety production, has better practicability and innovation, and provides a new model for other mines in gas emission. It provides some reference value for other mines in the direction of gas emission prediction.

Abstract:In response to the problem of large deformation of the surrounding rock in the 33104 transportation channel, based on the original anchor spray support, it is proposed to use anchor injection support to improve the stability of the surrounding rock. By simulating the changes in stress and displacement of the tunnel before and after grouting, it can be seen that the bearing capacity of the surrounding rock is improved after anchor grouting support, and anchor solids are formed in the shallow surrounding rock. The stress peak shifts to the deep, and the shallow surrounding rock is in a stress reduction zone. At the same time, grouting can bond loose and fractured surrounding rock into a whole, improve the bearing capacity of the surrounding rock, significantly improve the deformation of the surrounding rock, and achieve significant support effects.

Abstract:Aiming at the safety risks of the downward medium-deep sublevel open-stoping method in Baiyinuoer lead-zinc mine in Inner Mongolia, such as the large exposed area of the roof plate, the high height of the airfield, and the need to work on the upper part of the airfield in the process of mining, we combined the theory of the analysis of the stability of the airfield with numerical simulation and other methods to investigate the safety thickness of the roof plate and the stability of the mine field. The results of the study show that: when the span of the mining field is 5~30m, the safe thickness of the roof plate in the airspace is 4~15m; according to the Mathews stability diagram and numerical simulation analysis results, Baiyinuoer Pb-Zn Mine is a relatively stable mining field, and the structural parameters of the mining field with the phase height of 50m and the sublevel height of 13m and the sequence of mining back are reasonable. The study can provide certain reference for the safety production of similar mines.

Abstract:With the continuous acceleration of digital transformation and intelligent upgrading in the mining industry, the application of intelligent analysis systems in the mining industry has received more widespread attention. The Ampla platform is an intelligent management platform based on production models. This article introduces the application of an intelligent production analysis system developed based on the Ampla platform in a copper mine overseas, describing various indicators of related production systems and auxiliary production systems during the mining and processing, including information-based production management analysis processes such as ore production, energy consumption, performance, and equipment downtime analysis, as well as the application effects achieved.

Abstract:The 3D design of underground mine has become the development trend of consulting design and production enterprises, and it is also the pioneer of digital design, laying the foundation for the development of intelligent mines. At present, the 3D design of underground mining adopts 3D software for mining, and the use of specialization is limited, and the research of multi-discipline 3D collaborative design on the same platform has innovative significance for mining consulting design and production.In this paper, the application of Bentley software in 3D collaborative design of underground mines is explored, and secondary development and analysis are carried out.

Abstract:With the increasing improvement and strengthening of Chinas ecological protection system, the impact of ion type rare earth mining activities on the surrounding environment of mines is also receiving increasing attention from environmental supervision. This article will focus on the environmental management issues of ion type rare earth mines and discuss how to combine GIS, 3D modeling technology, data mining and analysis technology to incorporate pollution factors into the unified management of the smart environmental management platform. Based on these technologies, the digitalization of pollution warning and emergency accident response in ion type rare earth mines has been achieved, and a smart environmental management platform has been built. Hope to provide reference for ecological environment management in the mining process of ionic rare earth mines.

Abstract:The automatic mineral analysis system based on scanning electron microscope (SEM)-X-ray energy spectrometry (EDS) has some difficulties in distinguishing adjacent minerals with similar atomic numbers, and often requires special sample preparation methods or measurement schemes, or supplemented by other measurement methods. In this paper, a sample containing iron was tested and analyzed in one time by the BPMA system, and the detailed analysis results of magnetite hematite were compared with the typical characteristics of the sample under the optical microscope. The results show that the distinction of magnetite hematite is basically the same as that under the optical microscope. Although the method lacks precision, it is easy to operate, and it is suitable for the detection and analysis of magnetite hematite with low requirement for accurately distinguishing magnetite. To meet the needs of higher precision analysis, an automatic analysis system of optical image, BSE(backscattered electron map) and EDS spectra can be introduced into the optical microscope to realize the fusion of three signals through heterosource configuration.

Abstract:Taking a gold mine in Shandong as the research object, a gravity concentration-flotation combined process can be used to obtain a gold concentrate with a gold grade of 88.18g/t, a recovery rate of 17.00%, a silver grade of 16.28g/t, and a recovery rate of 2.01%. Additionally, a flotation gold concentrate with a gold grade of 55.59g/t, a recovery rate of 76.28%, a silver grade of 89.96g/t, and a recovery rate of 79.11% can be obtained. The gold grade of the total concentrate is 59.60g/t, with a gold recovery rate of 93.18%, a silver grade of 80.89g/t, and a silver recovery rate of 81.12%. The gold mine adopts a gravity concentration-flotation combined process, which can effectively recover cash and achieve comprehensive recovery of associated metal silver. This study can achieve comprehensive and effective recovery of gold and silver resources, providing important guidance for the recycling and utilization of this type of gold resources.