Fuzzy linear model for production optimization of mining systems with multiple entities

Planning and production optimization within multiple mines or several work sites (entities) mining systems by using fuzzy linear programming (LP) was studied.LP is the most commonly used operations research methods in mining engineering.After the introductory review of properties and limitations of applying LP,short reviews of the general settings of deterministic and fuzzy LP models are presented.With the purpose of comparative analysis,the application of both LP models is presented using the example of the Bauxite Basin Niksic with five mines.After the assessment,LP is an efficient mathematical modeling tool in production planning and solving many other single-criteria optimization problems of mining engineering.After the comparison of advantages and deficiencies of both deterministic and fuzzy LP models,the conclusion presents benefits of the fuzzy LP model but is also stating that seeking the optimal plan of production means to accomplish the overall analysis that will encompass the LP model approaches.     

Designing coal panels in the conditions of associated methane and spontaneous fire hazards

An increase in methane, spontaneous fire and bumping hazards in Polish hard coal mines, observed in the last two decades, led to the need to elaborate the tools allowing proper selection of a range of preventive measures to fight them at the stage of designing coal extraction. Designing the production of a coal seams in the conditions of associated methane and spontaneous fires hazards in Polish hard coal mines requires elaboration of the design standards for coal panels in gassy coal seams. This paper presents the guidelines on how to design production in the conditions of associated methane and spontaneous fire hazards.Presented tools and methodology since the very first research were many times verified by daily mining operations in the conditions of associated methane and spontaneous fire hazards, which confirms their significant contribution to the development of safe and economical mining operations.     

A multi-step approach for block-cave production scheduling optimization

Production schedules that provide optimal operating strategies while meeting practical, technical, and environmental constraints are an inseparable part of mining operations. Relying only on manual planning methods or computer software based on heuristic algorithms will lead to mine schedules that are not the optimal global solution. Mathematical mine planning models have been proved to be very effective in supporting decisions on sequencing the extraction of material in mines. The objective of this paper is to develop a practical optimization framework for caving operations’ production scheduling. To overcome the size problem of mathematical programming models and to generate a robust practical near-optimal schedule, a multi-step method for long-term production scheduling of block caving is presented. A mixed-integer linear programming (MILP) formulation is used for each step. The formulations are developed, implemented, and verified in the TOMLAB/CPLEX environment. The production scheduler aims to maximize the net present value of the mining operation while the mine planner has control over defined constraints. Application and comparison of the models for production scheduling using 298 drawpoints over 15 periods are presented.     

Deep mine cooling,a case for Northern Ontario:Part Ⅰ

Cooling energy needs,for mines in Northern Ontario,are mainly driven by the mining depth and its operation.Part I of this research focusses on the thermal energy loads in deep mines as a result of the virgin rock temperature,mining operations and climatic conditions.A breakdown of the various heat sources is outlined,for an underground mine producing 3500 tonnes per day of broken rock,taking into consideration the latent and sensible portions of that heat to properly assess the wet bulb global temperature.The resulting thermal loads indicate that cooling efforts would be needed both at surface and underground to maintain the temperature underground within the legal threshold.In winter the air might also have to be heated at surface and cooled underground,to ensure that icing does not occur in the inlet ventilation shaft-the main reason why cooling cannot be focussed solely at surface.     

数字矿山特征及未来数字遥控采矿系统模型

掠夺式开采产生的资源枯竭是传统采矿业面临的难题,建设数字矿山是有效改造和提升矿山竞争力和生命力的有效途径。数字矿山是矿山发展的趋势,无人遥控采矿是矿业发展的方向。     

数字矿井及其相关技术分析

结合数字地球和数字中国战略的提出 ,对未来的数字矿井进行了构想 ,给出了数字矿井的基本框架 ,全面、系统地论述了数字矿井的相关技术———矿井空间数据的获取与分析技术、网络数据库与分布式计算技术、数据仓库及数据挖掘技术、多种数据整合及虚拟现实技术 ,最后指出数字矿井的作用和意义     

真空作业提高地浸采铀钻孔抽液量试验研究

提高钻孔抽液能力是原地浸出采铀生产过程中的关键问题.本文采用在空气提升溶液的条件下,配上钻孔的真空作业来增加钻孔涌水量.试验表明,采用真空作业时钻孔的涌水量均有所增加,而且较稳定,平均增长率为20.3%.同时发现试验前后溶液的酸度和金属铀浓度变化甚微.采用真空作业,是强化地浸试验和生产过程的有效手段,可在地浸矿山推广应用.     

Deep mine cooling,a case for Northern Ontario:Part Ⅱ

Cooling energy needs, for mines in Northern Ontario, are mainly driven by the mining cooling technologies available and the cost to implement them in a 2500 m deep underground mine. The cooling technologies reviewed herein include mechanical and natural cooling systems, ranging from mechanical chillers to seasonal thermal storages. The economic and operating parameters for each technology were estimated and evaluated according to the mine's energy loads. Including consideration of any combined heat and power benefits of the technology, cooling tower requirements, etc., the resulting cost of implementation for each technology could be ranked. This showed that the natural thermal storage systems and conventional chillers were the most cost-effective, mainly since the natural systems had very low operating cost and the chillers had relatively low capital costs.     

New opportunities and challenges in surveying underground cavities using photogrammetric methods

The exploitation of the underground is currently undergoing a major transformation process. Besides mining, alternative ways of utilization are playing an increasingly important role. These alternative utilizations include the storage of gases, the disposal of radioactive wastes, and the implementation of geothermal storage facilities. In addition, more and more mining operations are being shut down, like the German hard coal mining industry in 2018. But the integrity of closed mines must be ensured in the post-mining phase. In order to capture such large and complex structures efficiently and reliably,new surveying techniques are required. A promising approach is the use of photogrammetric methods to generate three-dimensional models of the cavity. Photogrammetry is currently known mainly from aerial photography. It is conceivable to use such methods for underground applications. In recent years,significant progress has been made in the algorithm-based orientation of unstructured image sets. More powerful computer systems and the growing range of unmanned aerial vehicles could enable partially automated capture. However, a number of problems have to be solved for underground imaging techniques. Unfavorable exposure conditions complicate image alignment. Furthermore, the models must be integrated into existing surveying systems with a sufficiently high degree of accuracy. In order to consider the numerous technical aspects, the development of an integrated capture and evaluation approach is necessary. This could make an important contribution to the monitoring of critical cavities of different commodities. Such an approach would also fit into the current digitization trend in the mining industry and provide new opportunities for ground control in particular.     

Occurrence,predication,and control of coal burst events in the U.S.

Coal burst represented a major hazard for some U.S. mining operations. This paper provides an historical review of the coal burst hazards,identifies the fundamental geological factors associated with these events,and discusses mechanisms that can be used to avoid their occurrences. Coal burst are not common in most underground mines. Their occurrence almost always has such dramatic consequences to a mining operation that changes in practice are required. Fundamental factors influencing coal burst events include strong strata,abnormal strata caving,elevated stresses,critical size pillars and the lack of sufficiently sized barrier pillars during extraction. These factors interact to produce excessive stress,seismic shock and loss of confinement mechanisms. Over the 90 years of dealing with these hazards,many novel prevention controls have been developed including novel mine designs and extraction sequences,most of which are site specific in their application. Without an accurate assessment of the fundamental factors that influence coal burst and knowledge of their mechanisms of occurrence,control techniques may be misapplied and risk inadequately mitigated.     

《数字音频制作与创作》课程教学研究与探索

随着大数据时代数字媒体技术的发展,数字音频技术已得到广泛应用,极大程度上满足了人民对生产、生活的需求。数字音频作为多媒体素材之一,是多媒体教学研究中的一个重要内容。对数字音频制作与创作的教学进行系统的理论研究和探索,对提高教学质量、扩充学习资源以及为今后数字音频教学提供帮助等方面发挥积极作用。     

A comparative study of dust control practices in Chinese and Australian longwall coal mines

Mine dust is one of the main hazards in underground longwall mines worldwide.In order to solve the mine dust problem,a significant number of studies have been carried out regarding longwall mine dust control,both in China and Australia.This paper presents a comparative study of dust control practices in Chinese and Australian longwall mines,with particular references to statutory limits,dust monitoring methods and dust management practices,followed by a brief discussion on the research status of longwall mine dust control in both countries.The study shows that water infusion,face ventilation controls,water sprays,and deep and wet cutting in longwall shearer operations are commonly practiced in almost all underground longwall mines and that both Chinese and Australian longwall mine dust control practices have their own advantages and disadvantages.It is concluded that there is a need for further development and innovative design of more effective dust mitigation products or systems despite the development of various dust control technologies.Based on the examinations and discussions,the authors have made some recommendations for further research and development in dust control in longwall mines.It is hoped that this comparative study will provide beneficial guidance for scholars and engineers who are engaging in longwall mine dust control research and practice.     

Using self-determination theory to identify organizational interventions to support coal mineworkers' dust-reducing practices

Advancing the application of safety and health(SH) technologies is likely to remain a value in the mining industry. However, any information that technologies generate must be translated from the organization to the workforce in a targeted way to result in sustainable change. Using a case study approach with continuous personal dust monitors(CPDMs), this paper argues for an organizational focus on technology integration. Although CPDMs provide mineworkers with near real-time feedback about their respirable coal dust exposure, they do not ensure that workers or the organization will continuously use the information to learn about and reduce exposure sources. This study used self-determination theory(SDT)to help three mines manage and communicate about information learned from the CPDM technology.Specifically, 35 mineworkers participated in two mixed-method data collection efforts to discuss why they do or do not use CPDMs to engage in dust-reducing practices. Subsequently, the data was analyzed to better understand how organizations can improve the integration of technology through their management systems. Results indicate that using the CPDM to reduce sources of dust exposure is consistent with mineworkers' self-values to protect their health and not necessarily because of compliance to a manager or mine.     

Application of HEMS cooling technology in deep mine heat hazard control

This paper mainly deals with the present situation, characteristics, and countermeasures of cooling in deep mines. Given existing problems in coal mines, a HEMS cooling technology is proposed and has been successfully applied in some mines. Be-cause of long-term exploitation, shallow buried coal seams have become exhausted and most coal mines have had to exploit deep buried coal seams. With the increase in mining depth, the temperature of the surrounding rock also increases, resulting in ever increasing risks of heat hazard during mining operations. At present, coal mines in China can be divided into three groups, i.e., normal temperature mines, middle-to-high temperature mines and high temperature mines, based on our investigation into high temperature coal mines in four provinces and on in-situ studies of several typical mines. The principle of HEMS is to extract cold energy from mine water inrush. Based on the characteristics of strata temperature field and on differences in the amounts of mine water inrush in the Xuzhou mining area, we proposed three models for controlling heat hazard in deep mines: 1) the Jiahe model with a moderate source of cold energy; 2) the Sanhejian model with a shortage of source of cold energy and a geothermal anomaly and 3) the Zhangshuanglou model with plenty of source of cold energy. The cooling process of HEMS applied in deep coal mine are as follows: 1) extract cold energy from mine water inrush to cool working faces; 2) use the heat extracted by HEMS to supply heat to buildings and bath water to replace the use of a boiler, a useful energy saving and environmental protection measure. HEMS has been applied in the Jiahe and Sanhejian coal mines in Xuzhou, which enabled the temperature and humidity at the working faces to be well controlled.     

航空摄影测量在矿区1:2000地形图测绘中的应用研究

为验证无人机影像应用于矿区地形图测绘的可行性,本文以"冀中能源邯郸矿业集团太行矿业有限公司矿区基础地形图更新"为例实践了一套大比例尺地形图航空摄影测量的方法,并对空三加密及成图精度进行了分析。地形图检查点平面精度均在0.25 m以内,高程精度小于规范中误差的点数为80.1%,满足了矿区生产作业的需求。     

Progress of heat-hazard treatment in deep mines

Based on the urgency of thermal hazard control in deep coal mines, we studied the status of deep thermal damage and cooling technology both at home and abroad, summarized the causes of deep thermal hazard, analysed and compared the control technologies for deep thermal hazards. The results show that the causes of deep thermal damage can be attributed to three aspects, i.e., climate, geological and mining factors, of which the geological factors are deemed the major reasons for thermal hazards. As well, we compared a number of cooling technologies of domestic and overseas provenance, such as central air conditioning cooling technology, ice cooling technology and water cooling technology, with one other cooling technology, i.e., the HEMS cooling technology, which has a large and important effect with its unique "pure air" cooling technology, realizes the utilizing of heat resources from underground to the ground. This technology makes use of heat obtained underground; thus the technology can promote low-carbon environmental economic development in coal mines, in order to achieve lowcarbon coal production in China.     

Failure mechanism of pump chambers and their optimized design in deep mining at Qishan Coal Mine

Pump chambers, normally used as dominant structures in mining engineering to insure the safety and production of un-derground coal mines, become generally deformed under conditions of deep mining. Given the geology and engineering condition of Qishan Coal Mine in Xuzhou, the failure characteristics of pump chambers at the -1000 m level show that the main cause can be attributed to the spatial effect induced by intersectional chambers, where one pump is constructed per well. We developed an opti-mized design of the pump room, in which the pump wells in the traditional design are integrated into one compounding well. We suggest that the new design can limit the spatial effect of intersectional chambers during construction given our relevant numerical simulation. The new design is able to simplify the structure of the pump chamber and reduce the amount of excavation required.Based on a bolt-mesh-anchor with a rigid gap coupling supporting technology, the stability of pump chamber can be improved greatly.     

动态数学模拟在采矿中的应用

随着动态数学模拟方法在矿业中的应用日益增多,也暴露出不少问题.作者通过对无底柱分段崩落法矿山的模拟研究,得出了一套适合于矿山实际建模和模拟方法,具有一定的参考价值.也探讨了常用方法之间的关系和优缺点,以及在模拟矿山生产时最适合的方法.     

Use of the area of main influence to fix a relevant boundary for mining damages in Germany

In 2010, the fracking discussion in Germany caused a number of changes in German law, which came into force in 2016.Especially the production of gas had to be regulated.With the legislation amendment, the Subsidence-Area Mining Regulation has been revised, too.The changes expand the compensation of mining damages, especially to the extraction with drilling from the surface and underground storage.Although the Subsidence-Area Mining Regulation has been revised, the area of main influence(subsidence of 10 cm)remains to determine a relevant boundary for mining damages.The determination and prediction of this boundary above caverns are presented in this paper.In addition, further elements of ground movements and their relevance to mine damages are analyzed.The usage of the area of main influence to fix a relevant boundary for mining damages does not correspond to the relevant elements of ground movements.A limit for differences in subsidence(tilt) or horizontal changes in length should be preferred to describe the relevance of mining damages on buildings.Furthermore, this paper outlines the meaning of using the area of main influence to fix a relevant boundary for mining damages.     

Review of coal and gas outburst in Australian underground coal mines

Outburst of coal and gas represents a significant risk to the health and safety of mine personnel working in development and longwall production face areas. There have been over 878 outburst events recorded in twenty-two Australian underground coal mines. Most outburst incidents have been associated with abnormal geological conditions.Details of Australian outburst incidents and mining experience in conditions where gas content was above current threshold levels are presented and discussed. Mining experience suggests that for gas content below 9.0 m³/t, mining in carbon dioxide (CO₂) rich seam gas conditions does not pose a greater risk of outburst than mining in CH₄ rich seam gas conditions. Mining experience also suggests that where no abnormal geological structures are present that mining in areas with gas content greater than the current accepted threshold levels can be undertaken with no discernible increase in outburst risk. The current approach to determining gas content threshold limits in Australian mines has been effective in preventing injury from outburst, however operational experience suggests the current method is overly conservative and in some cases the threshold limits are low to the point that they provide no significant reduction in outburst risk. Other factors that affect outburst risk, such as gas pressure, coal toughness and stress and geological structures are presently not incorporated into outburst threshold limits adopted in Australian mines. These factors and the development of an outburst risk index applicable to Australian underground coal mining conditions are the subject of ongoing research.