CHINA MINE ENGINEERING

Abstract:In order to improve the prediction accuracy and adaptability, based on the blasting project of Meishan Iron Mine, this paper proposes a Dung Beetle Optimized Support Vector Regression (DBO-SVR) model for PPV prediction. The Pearson heat map is used to analyze the correlation between each feature and PPV (Peak Particle Velocity), and the mean square error and coefficient of determination are used as the model evaluation indexes. The prediction results of DBO-SVR, DBO-XGB, SVR and XGB are compared and analyzed. The mean square errors of the four algorithms were 0.028,0.152,1.084,0.226, and the determination coefficients were 0.985,0.917,0.408,0.877, respectively. The results show that the prediction effect of DBO-SVR algorithm is better than that of other models. The DBO-SVR algorithm model comprehensively considers the influence of multiple blasting design parameters on PPV, greatly shortens the training time of sample data, and accelerates the convergence speed of the model to meet the speed prediction requirements of actual blasting vibration. The prediction results are more accurate and the error is smaller, which can provide reference for the prediction of peak vibration velocity of similar blasting projects.

Abstract:Structural planes often control the stability of rock slope directly, so how to obtain, analyze and use the information of structural planes is very important. Taking Longsi CIV-1 slope as an example, the structural planes are analyzed and studied from data collection, analysis, spatial distribution model, structural characteristics and other aspects, and the distribution, attitude and spatial combination of the controlling structural planes are obtained. Based on this, the failure modes of dangerous rock body are preliminarily judged, and then the stability of dangerous rock body with different failure modes is analyzed by using limit equilibrium theory and UDEC software respectively. The results show that the influence degree of each working condition on slope stability is as follows: Combined condition ＞ rainstorm condition ＞ earthquake condition, and the results of theoretical calculation and numerical analysis verify the preliminary judgment of the stability of dangerous rock body by using the spatial combination relation of structural plane;Finally, the reinforcement and optimization scheme of dividing slope structure area based on the characteristics of the structural plane is proposed, which provides some reference for similar engineering treatment in the future.

Abstract:This paper focuses on the Qitou Mountain mining project in Sanmen County, Taizhou City, employing Plaxis2d for the simulation of the excavation process from small to large section adits. The results indicate that for large and small section adits, the crown settlement amount during sidewall pilot tunnel climbing excavation method is approximately 8.0% and 5.0% higher than that of the middle pilot tunnel, respectively. Considering the low construction efficiency caused by too small single-round advance and the poor safety associated with too large single-round advance, for small section adits, the single-round advance should be controlled at 2.5m, with the number of daily blasts during sidewall/middle pilot tunnel excavation not exceeding two times; for large section adits, the single-round advance should be controlled at 3.0m, with the number of daily blasts during sidewall/middle pilot tunnel excavation not exceeding three and two times, respectively.

Abstract:One open-pit copper mine employs pre-split blasting control technology for steep end-slope mining. To further optimize the pre-split blasting parameters and analyze their impact on blasting effectiveness, this study introduces a multiple linear regression model. The target variables are the pre-split hole spacing and the distance from the pre-split crack to the buffer hole row, while the unfragmented rock volume serves as the predictor variable. Pre-split blasting experiments are conducted using a two-factor three-level uniform design method. The research findings are as follows: ① The multiple linear regression model achieves a good fit with ，indicating its suitability for optimizing pre-split blasting parameters; ② Keeping other pre-split blasting parameters constant, it is recommended to select pre-split hole spacing and the distance from the pre-split crack to the buffer hole row as 1.1m and 2.4m, respectively, to achieve the best blasting results; ③ Pre-split hole spacing shows a positive correlation with the unfragmented rock volume, while the distance from the pre-split crack to the buffer hole row has a greater impact on the unfragmented rock volume.

Abstract:In this paper, three-dimensional geological modeling was carried out in the Shizhu bottom gold mine area with the help of Rhino modeling software, and feasibility study of multi-section mining scheme was carried out in the Shizhu bottom gold mine with FLAC3D. Two multi-section mining schemes were designed for excavation → filling simulation according to the production scale in the Preliminary Design of Shizhu Bottom. The settlement disturbance caused by the mining and filling process of the first and second schemes is very weak and almost unaffected. After the excavation of two middle sections at the same time, the maximum displacement in the vertical direction of the backfill roof surrounding rock is -2.85×10-2m. After the excavation of three middle sections at the same time, the maximum displacement in the vertical direction of the surrounding rock of the backfill roof is -4.35×10-2m. After excavation → filling, the stress reaches a new balance again. The maximum principal stress of the surrounding rock of the backfill roof is mainly affected by the tensile stress, and its maximum value does not exceed the tensile yield strength of the surrounding rock. The minimum principal stress is mainly compressive stress, which acts on the backfill body, resulting in shear-plastic strain zone, while the remaining parts only produce local shear-plastic strain zone.No large and penetrating plastic strain area has been formed, so under the premise of filling mining, the surrounding rock of the filling body is basically stable, and the mining schemes designed in Scheme 1 and Scheme 2 are basically feasible,However, from the perspective of displacement, scheme I is more conducive to surface stability and stope safety.

Abstract:Ensuring national energy security and achieving the strategic objective of “carbon peaking and carbon neutrality” can be facilitated by utilizing mining resources to construct underground storage. Determining the storage capacity of the subterranean reservoir and guaranteeing the stability and safety of the energy storage system need an understanding of the permeability properties of coal and rock layers in the mines storage area. Based on the concentrated brine underground storage project of Lingxin Coal Mine, this paper carried out an in-situ water injection test to study the permeability characteristics of coal and rock in the mining area, and investigate the permeability characteristics and water permeability of the remaining coal pillars, the top and the low plates of coal seams. The test findings indicate that the top plate of coals 15 and 16 has a stable flow rate of 1.76~8.82L/min, the bottom plate of coals 16 has a steady infiltration volume of 1.971.76~8.82L/min, and the stable flow value of the heritage coal pillar of each seam is 1.0~6.12L/min. On this basis, the permeability of the coal pillar in each seam is calculated to be 0.046~0.261Lu, that of the top plate to be 0.07~0.162Lu, and that of the bottom plate to be 0.042Lu. The permeability of the coal pillar in the 16 coal seams is the biggest, measuring 0.261Lu. Overall, coal and rock formations have poor water permeability, which is conducive to the construction of underground storage projects. Relevant research provides a foundation for the design and operation of underground storage.

Abstract:A mine in Southwest China is a soft coal seam, the mining face is a comprehensive release working face, the roadway leaves the top coal, and the dynamic pressure generated by the release of the top leads to serious deformation of the surrounding rock of the adjacent tunneling roadway. In view of the above problems, the multi-field coupling simulation software was used to simulate the strain evolution law of the surrounding rock under the influence of dynamic pressure, and combined with the comprehensive analysis of the on-site observation data of the off-loading instrument, it is known that the original support measures have the danger of surrounding rock instability under the influence of the dynamic pressure, and the reasons leading to the instability of the surrounding rock are analyzed, and preventive and curative measures are formulated. Through the construction of pressure relief holes to control the spread of dynamic pressure to the support area, U-beam steel + pipe shed support to improve the overall support strength. After the implementation of preventive measures, the maximum displacement of the tunnel perimeter rock affected by dynamic pressure was 50mm, and the overall deformation was relatively small. The preventive measures effectively control the problem of insufficient support strength of the soft coal roadway under the influence of dynamic pressure.

Abstract:This study aims to analyze the requirements, system architecture, and implementation methods of existing big data integrated analysis and prediction warning platforms, and to design and construct a coal mine safety assessment system based on comprehensive risk information management using the Python programming language. The system integrates data from various aspects such as the environment, equipment, and personnel, utilizing machine learning models for dynamic early warning and comprehensive assessment of coal mine safety risks. The operational results of the system indicate that it is feasible and practical, providing significant support for holistic management of coal mine safety, helping to improve safety management levels and reduce the occurrence of accidents.

Abstract:This article is based on the transient electromagnetic method technology to detect the location, shape, and water rich fractured areas of existing goaf areas. Combined with existing geological data, a comprehensive analysis is conducted on the scope and water accumulation conditions of goaf areas and karst water rich areas, providing scientific reference for the comprehensive investigation of hidden disaster causing factors. The research results indicate that the transient electromagnetic method technology hopes to provide new technical means and theoretical support for the geological characteristics and hazard assessment of phosphate mining goaf, and provide scientific basis for the safe operation of related engineering projects.

Abstract:In recent years, in view of the key problems of low grade of raw ore and high mineral processing cost in the process of mineral processing, the ore preseparation technology has been paid more and more attention by the mineral processing industry, and has been more and more applied in the non-ferrous metal ore processing. The advantages of heavy medium preseparation technology are: reducing the amount of ore entering the grinding and flotation process, improving the grade of raw ore, and effectively saving the storage capacity of tailings pond. In this paper, the heavy medium mineral processing technology is briefly introduced, and then the practical application case of heavy medium preconcentration of a lithium beryllium rare metal mine in Xinjiang is described in detail, aiming to provide valuable reference for the application of heavy medium mineral processing technology in the field of lithium beryllium rare metal mine.

Abstract:Taking a high arsenic and high sulfur copper zinc ore as the research object, a preferential flotation process is adopted to recover copper and zinc minerals from the ore. In the copper flotation stage, black catching agent No.25 is used as the collector of copper sulfide, calcium oxide and sodium humate are used as inhibitors of arsenopyrite, pyrite and sphalerite. In the zinc flotation stage, EF1108 was used as the collector for zinc sulfide minerals, and calcium oxide and sodium humate were used as inhibitors for arsenopyrite and pyrite, efficient recovery of copper and zinc minerals was achieved. In this study, the highly selective collector EF1108 was used as the collector of zinc sulfide minerals instead of the traditional xanthate agents, which played a high effect on the inhibition of arsenopyrite and pyrite at low alkalinity (pH 11.5).

Abstract:The Unity engine was originally developed for game development. However, with the development of technology, the Unity engine has also been widely used in other industries, such as art, automotive design, film and video creation, and more. Industrial applications have also become a major application direction for Unity, and have played an important role in mining projects. Traditional industrial intelligence is mainly achieved through automation and intelligent equipment, but due to its bad performance and poor correlation with other systems, its development has encountered bottlenecks. As a mature multi-platform 3D engine, the Unity engine not only solves the problem of correlation problem, but also better integrates with 3D design and multi-professional collaboration. In addition, the technology of game rendering can be fully applied to the industrial environment for expression. On the one hand, it solves the problem of traditional two-dimensional interface display limitations; on the other hand, it is also beneficial to the integration of various data displays. This article analyzes the advantages of Unity engine in terms of development environment, resource utilization, and cross-platform development based on its functional characteristics. Depends on the needs of the digital twin mine project, it elaborates on the application and effects of Unity in data fusion and multi-specialty collaboration, large-screen applications, mixed reality applications, and visualization solutions. Finally, based on the development situation of the industry, it summarizes the possible problems and future development directions of Unity engine and proposes suggestions for its use.

Abstract:In view of the problems that it is difficult to observe the movement state of ore particles inside the semi-autogenous mill and the unclear distribution of particles, the discrete element method is used to study and compare the influence of non-spherical and spherical ore particles on axial segregation in the semi-autogenous mill. The results show that non-spherical particles increase the dynamic angle of repose of the particle bed, and the motion state is more intense, and the particles in the cylinder have greater kinetic energy. The difference in particle size leads to the axial segregation phenomenon that large particles accumulate in the area near the end cover of the cylinder, while small particles accumulate in the middle area of the cylinder. However, the axial segregation phenomenon of non-spherical particles is more obvious than that of spherical particles.

Abstract:With the continuous increase of mining depth, high water pressure brings great challenge to mine production, high water pressure waterproofing gate will be more and more popular in engineering, and underground waterproofing gate is an important safety facility to prevent water penetration accident, more and more enterprises pay attention to and apply in production. Taking the chamber design of 7.5MPa waterproofing gate as an example, the author discusses the problems of structural design and the selection of discharge mode, and accumulates experience for the following similar projects.