VR-based digital twin for remote monitoring of mining equipment:Architecture and a case study

Background Traditional methods for monitoring mining equipment rely primarily on visual inspections,which are time-consuming,inefficient,and hazardous.This article introduces a novel approach to monitoring mission-critical systems and services in the mining industry by integrating virtual reality(VR)and digital twin(DT)technologies.VR-based DTs enable remote equipment monitoring,advanced analysis of machine health,enhanced visualization,and improved decision making.Methods This article presents an architecture for VR-based DT development,including the developmental stages,activities,and stakeholders involved.A case study on the condition monitoring of a conveyor belt using real-time synthetic vibration sensor data was conducted using the proposed methodology.The study demonstrated the application of the methodology in remote monitoring and identified the need for further development for implementation in active mining operations.The article also discusses interdisciplinarity,choice of tools,computational resources,time and cost,human involvement,user acceptance,frequency of inspection,multiuser environment,potential risks,and applications beyond the mining industry.Results The findings of this study provide a foundation for future research in the domain of VR-based DTs for remote equipment monitoring and a novel application area for VR in mining.

Development of Mining Technology and Equipment for Seafloor Massive Sulfide Deposits

Seafloor massive sulfide（SMS） deposits which consist of Au, Ag, Cu, and other metal elements, have been a target of commercial mining in recent decades. The demand for established and reliable commercial mining system for SMS deposits is increasing within the marine mining industry. The current status and progress of mining technology and equipment for SMS deposits are introduced. First, the mining technology and other recent developments of SMS deposits are comprehensively explained and analyzed. The seafloor production tools manufactured by Nautilus Minerals and similar mining tools from Japan for SMS deposits are compared and discussed in turn. Second, SMS deposit mining technology research being conducted in China is described, and a new SMS deposits mining tool is designed according to the environmental requirement. Finally, some new trends of mining technology of SMS deposits are summarized and analyzed. All of these conclusions and results have reference value and guiding significance for the research of SMS deposit mining in China.

Key technologies and equipment for a fully mechanized top-coal caving operation with a large mining height at ultra-thick coal seams

Thick and ultra-thick coal seams are main coal seams for high production rate and high efficiency in Chinese coal mines, which accounts for 44 % of the total minable coal reserve. A fully mechanized top-coal caving mining method is a main underground coal extraction method for ultra-thick coal seams. The coal extraction technologies for coal seams less than 14 m thick were extensively used in China. However, for coal seams with thickness greater than 14 m, there have been no reported cases in the world for underground mechanical extraction with safe performance, high efficiency and high coal recovery ratio. To deal with this case, China Coal Technology ＆ Engineering Group, Datong Coal Mine Group, and other 15 organizations in China launched a fundamental and big project to develop coal mining technologies and equipment for coal seams with thicknesses greater than 14 m. After the completion of the project, a coal extraction method was developed for top-coal caving with a large mining height, as well as a ground control theory for ultra-thick coal seams. In addition, the mining technology for top-coal caving with a large mining height, the ground support technology for roadway in coal seams with a large cross-section, and the prevention and control technology for gas and fire hazards were developed and applied. Furthermore, a hydraulic support with a mining height of 5.2 m, a shearer with high reliability, and auxiliary equipment were developed and manufactured. Practical implication on the technologies and equipment developed was successfully completed at the No. 8105 coal face in the Tashan coal mine, Datong, China. The major achievements of the project are summarized as follows： 1. A top-coal caving method for ultra-thick coal seams is proposed with a cutting height of 5 m and a top-coal caving height of 15 m. A structural mechanical model of overlying strata called cantilever beam-articulated rock beam is established. Based on the model, the load resistance of the hydraulic support with a large mining height for top-coal caving method is determined. With the analysis, the movement characteristics of the top coal and above strata are evaluated during top-coal caving operation at the coal face with a large mining height. Furthermore, there is successful development of comprehensive technologies for preventing and controlling spalling of the coal wall, and the top-coal caving technology with high efficiency and high recovery at the top-coal caving face with a large mining height. This means that the technologies developed have overcome the difficulties in strata control, top-coal caving with high efficiency and high coal recovery, and enabled to achieve a production rate of more than 10 Mtpa at a single top-coal caving face with a large mining height in ultra-thick coal seams; 2. A hydraulic support with 5.2 m supporting height and anti-rockburst capacity, a shearer with high reliability, a scraper conveyor with a large power at the back of face, and a large load and long distance headgate belt conveyor have been successfully developed for a top-coal caving face with large mining height. The study has developed the key technologies for improving the reliability of equipment at the coal face and has overcome the challenges in equipping the top-coal caving face with a large mining height in ultra-thick coal seams; 3. The deformation characteristics of a large cross-section roadway in ultra-thick coal seams are discovered. Based on the findings above, a series of bolt materials with a high yielding strength of 500-830 MPa and a high extension ratio, and cable bolt material with a 1 × 19 structure, large tonnage and high extension ratio are developed. In addition, in order to achieve a safe roadway and a fast face advance, installation equipment for high pre-tension bolt is developed to solve the problems with the support of roadway in coal seams for top-coal caving operation with a large mining height; 4. The characteristics of gas distribution and uneven emission at top-coal caving face with large mining height in ultra-thick coal seams are evaluated. With the application of the technologies of gas drainage in the roof, the difficulties in gas control for high intensive top-coal caving mining operations, known as ＂low gas content, high gas emission＂, are solved. In addition, large flow-rate underground mobile equipment for making nitrogen are developed to solve the problems with fire prevention and safe mining at a top-coal caving face with large mining height and production rate of more than 10 Mtpa. A case study to apply the developed technologies has been conducted at the No. 8105 face, the Tashan coal mine in Datong, China. The case study demonstrates that the three units of equipment, i.e., the support, shearer and scraper conveyor, are rationally equipped. Average equipment usage at the coal face is 92.1%. The coal recovery ratio at the coal face is up to 88.9 %. In 2011, the coal production at the No. 8105 face reached 10.849 Mtpa, exceeding the target of 10 Mtpa for a topcoal caving operation with large mining height performed by Chinese-made mining equipment. The technologies and equipment developed provide a way for extracting ultra-thick coal seams. Currently, the technologies and equipment are used in 13 mining areas in China including Datong, Pingshuo, Shendong and Xinjiang. With the exploitation of coal resources in Western China, there is great potential for the application of the technologies and equipment developed.

Waste-filling in fully-mechanized coal mining and its application

A fully-mechanized coal mining (FMCM) technology capable of filling up the goaf with wastes (including solid wastes) is described. Industrial tests have proved that by using this technology not only can waste be re-used but also coal resources can be exploited with a higher recovery rate without removing buildings located over the working faces. Two special devices, a hydraulic support and a scraper conveyor, run side-by-side on the same working face to simultaneously realize mining and filling. These are described in detail. The tests allow analysis of rock pressure and ground subsidence when backfilling techniques are employed. These values are compared to those from mining without using backfilling techniques, under the same geological conditions. The concept of equivalent mining height is proposed based on theoretical analysis of rock pressure and ground subsidence. The upper limits of the rock pressure and ground subsidence can be estimated in backfilling mining using this concept along with traditional engineering formulae.

New development of longwall mining equipment based on automation and intelligent technology for thin seam coal

The paper introduced complete sets of automatic equipment and technology used in thin seam coal face, and proposed the comprehensive mechanization and automation of safe and high efficiency mining models based on the thin seam drum shearer. The key technology of short length and high power thin seam drum shearer, and new type roof support with big extension ratio and plate canopy were introduced. The new research achievement on automatic control system of complete sets of equipment for the thin seam coal, which composed of electronic-hydraulic system, compact thin seam roof supports, high effective shearer with intelligent control system, and characterized by automatical follow-up and remote control technology, was described in this paper..

New development of sets equipment technologies for coal mine longwall face in China

Background of the development and achievement on sets equipment technologies for coal mine longwall face in China was reviewed initially. On the theoretical side, a coupling model of hydraulic support and surrounding rock, support pa- rameters optimization and threedimensional （3D） dynamic design method were presented. On the practical side, this paper out lined some of practical issues and discussed some relative methods and technologies. In thin seam coal longwall mining, how to lower equipment height is the first problem that should be solved. Roof pressure regularity, control of rooffall and collapse, and hydraulic support stability were investigated preferentially in 5-7 m coal seam longwall mining. The application of equip- ment for longwall mining with 5-7 m cutting height in China was concluded. The characteristics of full-mechanized top coal caving for extra thick seam coal were presented. The automation of top-caving hydraulic support and relevant equipment have achieved important breakthrough. At the end of this paper, further development of China＇s coal industry and longwall mining technologies and equipment were prospected in brief. This paper gives readers a comprehensive understanding of China＇s coal mine longwall face equipment technologies. It will give help to other countries on its coal mining development.

Capacity-based performance measurements for loading equipment in open pit mines

The purpose of this study is to develop an integrated framework for capacity analysis to address the influence of systematic hazardous factors on the haulage fleet nominal capacity.The proposed model was made to capture unexpected risks for mining equipment based upon data-driven method considering different scenarios.Probabilistic risk assessment(PRA)was employed to quantify the loss of production capacity by focusing on severity of failure incidents and maintainability measurements.Discrete-event simulation was configured to characterize the nominal capacity for mining operation.Accordingly,the system capacity was analyzed through the comparison of nominal and actual capacity.A case study was completed to validate the research methodology.The past operation and maintenance field data were collected for shovel operation.The discrete-event simulation was developed to estimate the rate of shovel nominal capacity.Then,the effects of undesirable scenarios were assessed by developing the PRA approach.The research results provide significant insights into how to enhance the production capacity in mines.The analyst gets a well judgment for the crucial elements dealing with high risk levels.A holistic maintenance plan can be developed to mitigate and control the losses.

Statistical approach to determination of overhaul and maintenance cost of loading equipment in surface mining

The purpose of this research was to develop a new approach in determination of overhaul and maintenance cost of loading equipment in surface mining. Two statistical models including univariate exponential regression (UER) and multivariate linear regression (MLR) were used in this study. Loading equipment parameters such as bucket capacity, machine weight, engine power, boom length, digging depth, and dumping height were considered as variables. The results obtained by models and mean absolute error rate indicate that these models can be applied as the useful tool in determination of overhaul and maintenance cost of loading equipment. The results of this study can be used by the decision-makers for the specific surface mining operations.

Hazard identification for equipment-related fatal incidents in the U.S.underground coal mining

Based on the number of fatalities per year, a persistent area of concern in mine safety continues to be equipment related. Data from the period 1995 through 2007 were studied in order to identify major hazards for underground mining equipment-related fatal incidents and to perform an analysis of those that occurred over the last 13 years. Reports on equipment-related fatal incidents were obtained from the Mine Safety and Health Administration （MSHA）. The results show that underground mining equipment including continuous miner, shuttle car, roof bolter, load-haul-dump （LHD）, Iongwall and hoisting contributed to a total of 69 mining-related fatalities. The study reveals that the major hazard for continuous mining equipment-related fatal incidents is ＂Failure of victim to respect equipment working area＂, while the highest number of fatalities for shuttle car is attributed to the hazard ＂Failure of mechanical components.＂ The study further reveals that the highest number of fatalities for roof bolter, LHD, and Iongwall are attributed to the hazards ＂Working under unsupported roof＂, ＂Failure of management to provide safe working conditions＂, and ＂Failure of mechanical components＂, respectively. It is determined that one fatality for the hoisting system is attributed to the hazard ＂Failure of mechanical components＂ and one to the hazard ＂Failure to follow safe maintenance procedure＂. Finally, approaches to prevention were also discussed in this paper.

The integrated monitoring system for running parameters of key mining equipment based on condition monitoring technology

An integrated monitoring system for running parameters of key mining equipmenton the basis of condition monitoring technology and modern communication networktechnology was developed.The system consists of a client computer with functions ofsignal acquisition and processing, and a host computer in the central control room.Thesignal acquisition module of the client computer can collect the running parameters fromvarious monitoring terminals in real-time.The DSP high-speed data processing system ofthe main control module can quickly achieve the numerical calculation for the collectedsignal.The signal modulation and signal demodulation are completed by the frequencyshift keying circuit and phase-locked loop frequency circuit, respectively.Finally, the signalis sent to the host computer for logic estimation and diagnostic analysis using the networkcommunication technology, which is helpful for technicians and managers to control therunning state of equipment.

Analysis and control of hydraulic support stability in fully-mechanized longwall face to the dip with great mining height

The working condition of the hydraulic support in working face can be divided into three kinds of situations in the following： roof fall and col,lapse with cavity, advancing support and supporting. Took single support with four-pole in Iongwall face to the dip as research object, control method was studied to avoid support instability in three situations mentioned above. Based on these researches, the major factors of influencing on support stability and its controlling measures were put forward. According to specific conditions of working face 1215（3）, which is fully-mechanized and Iongwall face to the dip with great mining height in Zhangji Coal Mine, Huainan Mining Group, the effective measures was taken to control supports stability..

A Life Evaluation System and its Application to Mining Machinery Equipment

Based on analyzing the mining equipment life evaluation theoretical system, the equipment life evaluation target system of the mining machinery is put forward taking the economic life, security life, reliability life and technical life as the targets. Then, the structure and model of the mining equipment life evaluation system are established and prepared for the realization of the system theoretically. Taking hydraulic support as the research object, the life evaluation system of hydraulic support is established and practice shows that the life evaluation system is feasible.

Study on safe thickness of overlying thin bedrock in fully-mechanized top-coal caving face with thick coal seam

To prevent support crush, the overlying strata safe thickness and its influential elements were studied by the adoption of theoretical analysis, numerical simulation and in-situ measurement. According to the production and geological condition of first face in Sima coal mine, the results indicate that the clay contains large permissible bearing ability and has better arching force. After mining destruction, stable structure is formed in bedrock to ensure face safety. The clay thickness ＆ bedrock thickness are the key influential elements to stable structure. The minimal bedrock thickness is about 40 m to ensure safe mining under loose surface soil condition. When surface soil contains mainly thick clay, it forms steady structure with the composition of thin bedrock, so that it can reduce minimal thickness of bedrock and to ensure safe mining. When clay thickness is 40 m, minimal bedrock thickness is 20 m. When clay thickness is 30 m, minimal bedrock thickness is 30 m. Bearing pressure peak ranges from 5 to 15 m in the front face under thin bedrock condition. The bearing pressure distribution range is 15 m. Main roof break distance is small, and initial weighting of main roof is not distinctive, while first periodic weighting of main roof is quite distinctive.

刚果(金)SICOMINES铜钴矿提高铜、钴选矿回收率研究与实践

刚果(金)SICOMINES在处理高氧化率铜钴矿的选矿生产过程中,由于现阶段处理矿石氧化率远高于设计值,此类矿石氧化率高、含泥量大、可浮性差,导致利用现有的生产工艺流程和浮选设备,氧化矿浮选精矿产率及铜、钴回收率较低。为提高铜、钴回收率,在针对原矿性质进行系统研究的基础上,结合生产实际,对工艺流程和设备进行优化:首先是取消钴浮选精选,且将氧化铜浮选和钴浮选扫选流程改为开路;然后增加泡沫导流槽的数量,改进了泡沫导流槽的结构和安装角度。改进后,氧化铜精矿和浮选钴精矿产率分别提高1.46个百分点和3.36个百分点,增幅分别达到40.33%和79.25%,总铜、总钴回收率分别提高4.17个百分点和3.53个百分点。生产工艺及设备改进取得了较好的效果,对处理刚果(金)同类型高氧化率铜钴矿石具有较好的借鉴意义。

地下金属矿开采装备短间隔智能调度体系研究

作为矿山生产管理的重要内容,生产调度优化与管控可以充分利用产能、降低开采成本,因此成为现代矿山降本增效的有效手段。通过精细化调度管理和智能决策方法,实现复杂条件下的开采装备高效协同作业,充分提高调度管控效率和矿山生产能力,是现阶段矿山开采装备智能调度需要解决的关键问题。以地下金属矿山开采装备调度过程为研究对象,以提高开采装备的作业效率和生产能力为目的,研究了开采装备智能调度管控模式、决策支持算法和集成化应用。针对现代地下金属矿生产实时化、精准化与智能化管控的新需求,提出了开采装备短间隔智能调度新模式,形成了以“任务分解—任务配置—运输配置—作业指令—响应修正—分析反馈”为特征的短间隔闭环调度方案。设计了包括开采装备任务配置与调度优化算法、面向多级动态配矿的矿石流优化算法、无轨装备集群调度控制优化算法的智能化决策支持算法库,实现由人工经验到智能决策的转变。将开采装备短间隔智能调度体系进行综合示范应用,满足了现代矿山精细化管控和智能化决策需求。研究成果对于地下矿山开采装备作业过程的精细化管控与开采效率提升具有指导意义,同时也为现代地下金属矿山的生产调度管理提供了理论和方法支撑。

数字孪生驱动的掘锚设备跟踪定位与碰撞检测方法研究

掘锚自动化作业是煤矿巷道智能掘进的关键,针对当前掘锚设备交替作业过程中相对位姿测量和碰撞检测难题,提出一种数字孪生驱动的煤矿井下掘锚设备跟踪定位与碰撞检测方法。首先,为克服井下掘进工作面低照度、高粉尘、复杂背景干扰的影响,以多点红外LED标靶作为信息源,通过工业相机采集红外LED特征点图像,利用Hough轮廓检测与质心法提取光斑中心并通过二进制编码识别标靶ID,采用改进稀疏光流算法对光斑进行跟踪,同时建立基于PNP的掘锚设备位姿解算模型,采用对偶四元数获得设备间相对位姿。其次,利用数字孪生技术,基于Unity3D平台建立对应实际尺寸的掘锚设备及工作面数字孪生模型,利用Socket通信方式实现虚拟空间与物理实体之间的实时数据传输与交互,在虚拟空间中实现掘锚设备实时位姿的三维可视化,结合任意多边形OBB(orientedboundingbox)碰撞检测算法,实现掘锚设备虚拟碰撞检测。最后,搭建实验平台进行掘锚设备位姿测量试验,同时对虚实运动轨迹和碰撞检测效果进行验证。实验结果表明:掘锚设备跟踪定位实验的位置误差不超过20mm,角度误差不超过0.30°;虚实位置坐标对比中X轴方向最大误差不超过1.14mm;Y轴方向最大误差不超过1.10mm,能够保证系统虚实一致性和同步性,满足掘进工作面作业过程中掘锚设备实时跟踪定位及碰撞检测的要求。

选矿厂智能化建设目标与实施路径

选矿厂的智能化升级转型是建设现代矿山企业的必然选择,其建设目标及实施路径与广义智能工厂建设有着显著差异。本文结合选矿厂智能化建设背景、面临的问题,探讨了选矿厂智能化的建设目标,提出了智能选矿厂的建设路径:智能装备与智能感知、过程自动化稳定运行、工艺优化控制、信息化生产管理以及与之匹配的生产组织管理体系,最后给出了选矿厂智能化建设的实施步骤建议。

时间控制模式在血液分离机运行管理中的价值研究

目的:构建血流分离机时间控制管理模型,探讨其在血液分离机运行管理中的应用价值。方法:分析成分血采集血液分离时间延迟原因,采用数据挖掘算法分析其影响因素与时间控制水平的关联性,在时间评估预测等多维度构建血液分离时间控制管理模型,制定时间控制管理对策。选取2019-2022年上海市徐汇区中心医院的600名献血者和采血期间临床在用的17台血液分离机,根据管理模式不同,将其分为对照组(300名献血者,14台血液分离机)和观察组(300名献血者,15台血液分离机,含对照组12台和新增加的3台),对照组血液分离机采用质量控制模式,观察组采用时间控制模式,对比两组成分血采集过程中的问题数、延迟比例、满意人数和参与采集成分血工作的相关医务人员考核成绩。结果:观察组成分血采集过程中发生设备、医用耗材、医务人员及献血者相关问题的献血者人数分别为11名(占3.7%)、17名(占5.7%)、7名(占2.3%)和18名(占6.0%),均少于对照组,其差异有统计学意义(x^(2)=7.192、6.822、8.153、11.405,P<0.05);观察组成分血采集过程中血液分离机运行正常、明显延迟和显著延迟的献血者人数分别为236名(占78.7%)、46名(占15.3%)和18名(占6.0%),运行正常人数占比高于对照组,明显延迟和显著延迟占比低于对照组,其差异有统计学意义(x^(2)=17.821、7.131、8.549,P<0.05);观察组献血者满意人数为284名(占94.7%),高于对照组,其差异有统计学意义(x^(2)=30.171,P<0.05);参与观察组献血者成分血采集工作的医务人员考核成绩为(91.14±4.86)分,高于对照组,其差异有统计学意义(t=4.587,P<0.05)。结论:时间控制模式能够控制血液分离机运行问题发生概率,缩短血液分离机运行延迟时间,改善献血者献血体验和采血服务质量,提高医务人员业务水平。

硬岩非爆机械化采掘技术发展与展望

近年来,随着地下工程建设及资源开采规模不断扩大,硬岩机械化采掘技术和装备得到不断创新和发展。传统钻爆法因其危险性高、衍生破坏大,难以满足现代岩石工程发展需求。硬岩非爆机械化采掘技术以其安全、高效、经济、智能化进程快等优势已成为现代岩石破碎工程的主要发展方向。从岩石可切割性、机械刀具(破岩工具)和机械装备3个角度对硬岩非爆机械化采掘技术的发展现状进行了论述。研究表明:岩石可切割性从单一指标评价向多指标综合评价发展;机械刀具类型呈现多样化,刀具性能伴随合金技术和涂层技术的发展而不断提质,并且刀具的设计制造注重在刀具硬度、耐磨蚀性与冲击韧性间寻找最佳平衡点来提高刀具使用寿命;破岩机械装备正在逐步向大型化、重型化、智能化、多样化、精细化发展,以更好地实现硬岩的高效、安全、经济、精细化采掘。在上述分析的基础上,展望了硬岩非爆机械化采掘技术的未来发展方向,认为未来亟须攻克的难点有:①建立深部岩石破碎力学与能量模型,探寻深部硬岩高应力诱导利用与高储能调控方法,开发硬岩诱变改性降危增割协同破岩方法与技术;②明晰硬岩破碎过程的多场多相耦合及多尺度破裂、破坏、破碎过程,开发机械刀具、水力、热力等多源联合破岩技术及装备;③揭示深部破岩扰动诱发高储能岩体动力灾害的力学及能量机制,提出针对性的防控方法;④开发与岩体特性、地应力条件、破岩需求协同匹配的精细化智能破岩技术与装备,形成非爆机械化智能采掘方法与技术体系;⑤构建非爆机械化采掘全过程管理模式,完善硬岩非爆机械化采掘作业流程。通过以上研究攻关,有望促进非爆机械化采掘技术在硬岩工程中的规模化应用,实现硬岩的安全、高效、绿色、智能采掘。

基于FreeRTOS的无线便携式多气体检测仪设计

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