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Adverse ground behavior events, such as convergence and falls of ground, are some of the most significant challenges and hazards in underground mines. Our goal is to work toward mine-wide, digital, and real-time three-dimensional geotechnical situational awareness and predictive capabilities in complex underground mining operations. This will benefit operators, engineers, and management by enabling them to develop a more proactive approach to ground control. To this end, and inspired by research in the field of remote sensing and autonomous robotics, this paper assesses the potential of mobile light detection and ranging (LiDAR) data acquisition for high-frequency, high-accuracy monitoring tasks in Global Navigation Satellite Systems (GNSS) deprived underground mines. Limitations of current monitoring practices are reviewed. Relevant academic and commercial developments in the fields of indoor mobile mapping systems (MMSs) and simultaneous localization and mapping (SLAM), robust autonomous robotic platforms, and automated remote sensing data processing are highlighted, and their current shortfalls are evaluated. To conclude, the ramifications of this work for the development of future autonomous underground mine monitoring solutions are discussed.

Jul 28, 2020

Waste areas of a mine should be sealed especially if there is a risk of spontaneous combustion. Leakage through and around such seals can be problematic. Pressure balancing has been one of the favored options to prevent the ingress of air into these waste areas. Balance chambers require maintenance and monitoring to ensure that they are effective. This paper explores the use of inert gas as a means of controlling ingress of air and egress of waste gases as a means of reducing leakage around seals.

Jan 1, 2009

Invensys’ recently introduced Field Device Manager for Foxboro I/A Series distributed control systems provides the industry’s first solution that takes advantage of both the latest Enhanced Electronic Device Description Language (Enhanced EDDL) and FDT technologies. This combination provides comprehensive lifecycle support to configure, calibrate, commission, diagnose and optimize the performance of any vendors’ foundation fieldbus device. The I/A Series Field Device Manager enables users to take advantage of any EDDL, Enhanced EDDL and/or FDT host deliverables supplied by the device vendor.

Jan 1, 2007

By D. H. Horswill

Red Dog, the world’s largest zinc mine, is located ninety miles north of the Arctic Circle in northwest Alaska on lands owned by the Inupiat Eskimo organization called NANA. NANA received a subsurface title over this resource as part of their settlement lands under the Alaska Native Claims Settlement Act and subsequently entered into a Lease Agreement with Cominco in 1982. Cominco, an international mining company focused on zinc, built and operated the mine. NANA’s principle objective in the development of the mine was to have it contribute to the development of sustainable communities within their traditional region. This meant creating job opportunities in a modern economy while preserving the traditional subsistence lifestyles. Preservation of their culture, language, and traditions are as important to the NANA people today as they were through ages past. The principles of sustainable development – matching economic, environmental, and social goals through continuous communications and high commitment to efficient and effective operations – have been core values for the Red Dog Mine from the beginning. This paper will describe how a large mining operation in a remote corner of the world has been able to contribute toward sustainable development in that region.

Jan 1, 2000

By J. Weng

The equations of heat conduction are numerically solved for two kinds of artificial freezing- mechanical freezing and liquid nitrogen freezing. A two dimensional finite difference model simulating the freezing field is developed. The procedure introduces a way to simulate the effect of latent heat released when water transforms from liquid to solid. The procedure also produces a way to calculate the harmonic mean of heat conductivity used when dealing with heterogeneous material. The theoretically derived temperature distributions in frozen soil are given and compared with measured data. An analysis is made on the thermal design in shaft freezing. The average temperature of frozen soil is calculated by using numerical integration. The regularity of development of frozen soil radius is revealed and given in an appropriate mathematical model.

Jan 2, 1984

By R. Oler

The need for yieldable ground support, particularly in high stress or deep mining conditions, has grown in recent years. This paper highlights some of the current industry limitations and provides selection criteria for a new yielding ground support system, DSI?s Dynatork Bolt. This bolt distinguishes itself by withstanding 16 ? 30 kJ of energy deflecting loads anywhere from 7 ? 20 tons (depending on the energy). A summary of the laboratory test results and case studies will also be presented as a measure of the performance of this dynamic product.

Jan 1, 2012

By LeRoy D. Loy

To facilitate effective land reclamation and comply with existing state regulations, surface coal mine operators have in recent years adopted new mining techniques and equipment utilization for steep-terrain mining. In contrast to direct spoiling with draglines or shovels, these new mining methods require some form of overburden haulage from the excavation face to the point of reclamation. Although current mining methodologies such as Block-Cut, Modified Block-Cut, and Mountaintop Removal with Head-of-Hollow Fills have proven effective in achieving reclamation objectives, some production problems have resulted from pit congestion and excessive equipment delays. Recognizing this problem, the United States Bureau of Mines contracted Skelly and Loy to design innovative mining concepts utilizing conveyor haulage in place of trucks, loaders, dozers and scrapers. Project objectives required definition of current bottlenecks and development of mining systems to: alleviate bottlenecks; increase production potential; facilitate additional resource recovery; enhance reclamation; reduce safety hazards; and improve mining economics. Successful completion of project goals within a four year program involves systematic implementation of the following separate work phases: 1) Develop Concepts for Block-Cut Mining Systems; 2) Determine the Economic and Technical Feasibility of Concepts; 3) Prepare Detailed Design and Specifications of Concepts; and 4) Prepare Specifications for Conducting Field Tests of the Most Promising Concepts. At the time of this publication, Phases 1 and 2 are finalized with Phase 3 efforts well underway.

Jan 1, 1977

By G. A. Grandy, P. F. Thomas, C. D. Danecki

When considering the mill drive system for a grinding application, a large number of questions must be answered. Depending on the mill size and type, the mill can be driven by several configurations of drive systems: a single low-speed motor connected to a pinion driving a ring gear, two low-speed motors connected to two pinions and driving a ring gear, or a gearless motor mounted directly. In addition, a gear drive system can have a reducer placed between a high-speed motor(s) and pinion(s) or a power path splitting pinion stand. In some designs the reducer is integral with the pinion stand driven by a high-speed motor. The technical and commercial implications of several mill drive options are presented. Initial cost, cost of installation, cost of commissioning, and cost of operation and maintenance are presented for each drive option considered. The impact of each drive system on the design, cost and operation of the overall plant electrical system is discussed. Also, consideration is given to mill drive availability, and the potential cost resulting from delays in plant production.

Jan 1, 2001

By Michael Jatczak

The San Vicente Tunnel Project is an 11-mile water tunnel constructed for the San Diego County Water Authority. One of the many challenges of the project included tunneling a 22,000-foot single-heading tunnel on the western half of the job in varying geology using a 3.66m (12ft) diameter open shield excavator or ?digger shield.? This paper will discuss the design considerations for the temporary liner, the tunneling, and ancillary equipment. It will also highlight the challenges faced while mining this geology, explain the methods implemented to drive this section of tunnel, and discuss the experiences while performing mechanized tunneling in an extensive and varied San Diego geology.

By J. H. Zietsman

Ilmenite smelting furnaces must be operated with a freeze lining of frozen slag to protect sidewall refractories from chemical attack by liquid slag. The process has two main control objectives: Firstly the slag TiO2 content must be controlled according to specification, and secondly a safe freeze lining thickness must be maintained. This text only concerns itself with the second objective. Freeze lining thickness cannot be measured directly due to conditions inside the furnace. It is therefore inferred from signals of thermocouples installed into the furnace sidewall. These signals are used as the 'controlled variables' in the freeze lining thickness control loop. The dynamic characteristics of these signals are the focus of this text. During this study a model of the process was constructed to study interactions between the slag bath and the freeze lining. This model was used to conduct simulation-type experiments to study the influence of various parameters (temperature, slag composition, ilmenite feed rate, reductant feed rate, power input, etc.) on the slag bath, freeze lining, metal bath, furnace wall and other parts of the process. In the case of the furnace wall, the modelling results were first plotted in the form of time-dependent isotherms. The dynamic thermal behavior of the furnace wall became evident from these results. To illustrate the dynamics of sidewall thermocouple signals, the results were also plotted as time lags between events occurring in the slag bath, and the time when a thermocouple registered a temperature change. The events studied included sudden changes in slag bath state (composition and temperature), changes in operating setpoints (ilmenite feed rate, reductant feed rate, power input), and operational errors (complete loss of reductant or of all feed). All of the result sets showed significant lags between occurrences in the slag bath and temperature changes in the refractory wall. The delays are such that it appears impractical to rely on sidewall thermocouple signals for warning of impending damage to the refractory wall, or for purposes of actively controlling freeze lining thickness. Some measures are suggested to improve the usefulness of these signals during furnace operation.

Jan 1, 2005

By C. Geier

Our national interests are best served by having well-trained first responders available for rapid response to emergency situations in underground mines. However, recent mine disasters have indicated that focused training on hazard recognition, decision making, leadership, and incident command center protocols needs to be incorporated into a comprehensive training plan for all personnel involved in a mine rescue. Currently, there are very few training opportunities for the mining professionals responsible for making the crucial decisions needed during a mine emergency. With recent technical advances, it is now feasible to use a computer-based simulator to train mine rescue personnel for mine emergencies in their mine or any other mine at a convenient location without interrupting normal mining operations. This simulated environment teaches underground search and rescue procedures, communications, and decision making based on real-time information and hazard recognition. Since 2010, the Colorado School of Mines (CSM) has offered computer simulated mine rescue training using an incident command center (ICC) directed towards enhancing decision making and communication skills. To support this training, CSM partnered with Rite Solutions, Inc. to modify, enhance, and create simulation software for mine rescue applications. The focus of this partnership is to modify existing simulation technology to address the unique nature of underground rescue operations, make it applicable to any underground operation, create generic scenarios, and develop customized computer simulations, including scenarios, for specific sites. Need The CSM mine rescue computer simulator helps mine rescue teams train for mine disasters where they would be deployed for the rescue and recovery of a mine. It provides additional, readily accessible opportunities to train without affecting mining operations. While the simulator lacks the physical demands of a rescue situation, it is very effective for teaching mine rescue procedures as rescuers seamlessly walk through the process and work out issues before going underground. The mine rescue simulator also introduces students to coordination through an ICC which stresses the use of effective communication and hones decision making skills. Most of the mine rescue teams participating in this study had never trained with an ICC controlling the actions of the mine rescue team making this an extremely valuable training opportunity. In addition, the mine rescue computer simulator allows instructors to modify mine rescue scenarios and tailor the scenarios to each team?s individual needs resulting in a more versatile training experience. The goal is to ensure that all teams receive the maximum benefit from each training session.

Feb 27, 2013

By S. Ersayin

In 1998, the Concentrator Modeling Center was established within the Coleraine Minerals Research Lab, Coleraine, Minnesota, to develop models for simulation of iron ore processing plants, and to assist plant operators in improving performance of their aging plants. The short-term objective was to develop necessary models for reliable simulation using conventional techniques, while the long-term objective was set as liberation-based modeling and simulation of these plants. The short-term objective was achieved in 2002 after the development of models for magnetic separators, hydro-separators and fine screens. A project funded by the U.S. Department of Energy was carried out to demonstrate the capability in improving iron ore processing at the Minorca plant. As a result of this study, a 10% improvement in throughput at the plant was obtained, and simulation became a desired tool for plant operators. A significant step in the long-term objective was reached in 2005 with the development of a liberation model. This was followed by incorporation of models capable of processing liberation data into the software. By early 2007, the Concentrator Modeling Center had the capability of performing liberation-based simulation of entire plants.

Jan 1, 2009

By E. A. Sarver

The Fe(II) regeneration process is an important aspect of Alternate Anode Reaction Technology (AART) for copper electrowinning (EW). In AART, Fe(II) is oxidized to Fe(III) at the anode during EW, and it must be regenerated to maintain recyclable electrolytes. Regeneration is achieved via Fe(III) reduction by SO2(aq), and the reaction is catalyzed by activated carbon particles. To better understand this process, a kinetic model was developed and experimentally validated for the Fe(II) regeneration in the current work. The investigation focused on the primary reaction mechanism and the reaction rate dependence on four variables: carbon particle size, flow rate, initial Fe(III) concentration and initial SO2 concentration. The Fe(II) regeneration reaction is mass-transfer controlled in the presence of activated carbon. Carbon particle size and initial Fe(III) are the most influential factors under the conditions tested. Initial SO2 concentration is insignificant to the reaction rate.

Jan 1, 2007

By S. Christiansen, G. R. Winslow, R. W. Kobler

Todays End of Life vehicles are shredded and their metal components recovered and recycled by standard methods. The remaining non-metallic fraction is shredder residue, and contains vast amounts of high value engineering plastics. None are today recovered. Discussed are the developmental approaches used in the first process to recover these valuable plastics. Examined are initial laboratory studies, pilot plant design and construction, product development, results, and flowchart explanations.

Jan 1, 2001

By Paul H. Madsen, Victor S. Romero

The Tren Urbano project in Puerto Rico includes a 19 m diameter tunnel constructed by the stacked drift method, which involves installation of a pre-supported concrete arch using multiple tunnels. Geotechnical conditions consisted of weak rock and highly weathered, unstable alluvial soils. Due to low cover, reinforcement of the arch was required. Ground behavior ranged from firm ground to mixed-face to raveling and flowing ground. Consequently, construction of the individual drifts involved many different soft-ground techniques such as steel set supports, shotcrete support, shield tunneling, forepoling, and consolidation grouting. During construction, the design was modified to improve constructability. Although settlement was experienced during excavation of the drifts, arch movements were within predicted limits and minimal surface settlement was observed upon excavation of the interior.

Jan 1, 2001

By Claudio Flores Martinez

The prospect of accomplishing economically and scientifically profitable deep-sea mineral mining within this decade or the next one is of particular interest to the emerging discipline of astrobiology which is concerned with the origin, distribution and future of life in the Universe. Several planetary bodies within our own Solar System such as Jupiter’s moon Europa and Saturn’s Enceladus now appear to be potentially habitable, or life-friendly, in terms of the three prerequisites for life as we know it: a sustained body of liquid water, biogenic elements (C, H, N, O, P, S) and energy sources to fuel metabolic reactions. Europa, for instance, possesses a global subsurface ocean, believed to be up to 100 km in depth, hidden beneath a kilometer-wide ice-sheet. A silicate mantle is directly interacting with a cold, aphotic ocean in which tidal forces might drive geological seafloor activity that results in the creation of hydrothermal systems. These locales are commonly hypothesized to be the cradles for an alternate origin of life on Europa. Especially alkaline hydrothermal springs, as found at Lost City, have been at the center of modeling the prebiological evolutionary dynamics preceding cellular life. Serpentinization-like reactions are also possibly fueling metabolic networks in putative microbial communities found in the oceans of the icy moos. Major space agencies around the globe are planning future space missions aimed at exploring and eventually characterizing potential life forms in these habitats. The technology needed for this exploration effort resembles the requirements for a successful deep-sea mineral mining industry: highly efficient AUVs (also equipped with biologically-oriented instrumentation), swarm robotics, landers, seafloor rovers and general high-pressure, cold temperature extreme environment engineering. Interestingly, science questions of deep-sea mineral mining and astrobiology converge too: the hypothesis of life originating at hydrothermal systems, the biogeographical distribution of species among these environments, adaptations of extremophilic organisms across the three domains of life and adequate autonomous robotic systems to assess the complexity of deep-sea biological communities. This presentation attempts to present a two-fold view of advanced planetary exploration that relates to a sustainable vision of deep-sea mineral mining: charting our oceans and developing technologies least harmful to endemic biology can propel the design and prototyping of future robotic planetary probes bound for aquatic missions on alien moons. Space industry, government and public interest towards a broadened planetary perspective on deep-sea mineral mining is promoted by addressing an astrobiological rationale of this endeavor.

Sep 1, 2014

By Susana Bolhão Muiños, José Hipólito Monteiro, Martin Frank, James R. Hein, Henrique Garcia Pereira, Fátima Abrantes, Tracey Conrad, Luís Gaspar

In spite of all the work that has already been done on ferromanganese deposits, studies on the Atlantic Ocean occurrences are still in their infancy and there is a clear need for investigations concerning the origin, distribution, and resource potential assessment of these deposits. Nevertheless, studies already carried out on northeast Atlantic seamounts indicate the general presence of ferromanganese deposits of hydrogenetic origin, i.e. deposits formed by direct precipitation of colloidal, hydrated metal oxides that are scavenged from the water column on hard-rock substrates. The hydrogenetic precipitation promotes the enrichment of ferromanganese crusts in many trace metals, most of which are of economic interest, such as Co, Ni, Te, rare earth elements, and platinum-group elements and thus ferromanganese crusts are considered an important metal resource.

Sep 1, 2014

In this study, the flotation performances of ethoxycarbonyl thionocarbamate (ECTC), dialkyl thionocarbamate (DATC) and xanthate copper sulfide collectors are compared by the structure-reactivity relationship using generalized perturbation theory and density functional calculation at the B3PW91/6-31G(D) level. The electron-donating power of xanthates is strong and, therefore, xanthates can strongly react with metal cation on the surfaces of copper and iron sulfide minerals through the formation of normal covalent bonds. This explains the poor selectivity of xanthates and also the high pH levels (above 13) required for the flotation separation of copper/iron sulfide minerals. DATCs are more selective for copper sulfide flotation, particularly against gangue iron sulfides. Although less powerful than xanthates, DATCs can perform copper/iron flotation separation at lower operating pH (commonly at pH levels below 11.5). ECTCs use an ethoxycarbonyl replacing an alkyl N-substituent in DATCs. The presence of the ethoxycarbonyl group effectively changes the functional group of collector from -C(=S)NH- to -C(=S)NHC(=O)-. The strong electron-withdrawing ethoxycarbonyl group adjacent to the C=S group decreases the electron density of the sulfur atom, which improves ECTC?s selectivity against iron sulfide minerals at slightly alkaline conditions. The lowest unoccupied molecular orbit (LUMO) of ECTC, which is constituted by the pz-orbit of every atoms in the conjugate -O-C(=O)-N-C(=S)-O- group and which is pleased with accepting richly d-orbital electrons (feedback electrons) from the (t2g)6(eg)3Cu(II) or t6e4Cu(I) configuration of copper cation on the surfaces of copper sulfide minerals, resulted in the formation of dative p-bond. The iron atom, which has a (t2g)6Fe(II) or (t2ga)3(ega)2 Fe(III) configuration on the surfaces of iron sulfide minerals (Fe(III) is the predominant composition at alkaline conditions), has difficulty in offering its d-orbital electrons (feedback electrons) to ECTC?s LUMO. ECTC collectors are powerful for copper sulfide minerals and very selective against iron sulfides, which has been further confirmed by UV spectra and bench-scale and industrial-scale flotation tests.

Jan 1, 2008

By D. A. Norrgran, J. A. Wernham, D. E. Walsh

A qualitative test program was sponsored jointly by the University of Alaska and Eriez Magnetics, in order to study placer gold nugget recovery using an eddy-current separator. Various gold nuggets from Alaska, ranging from 6.4 mm to 63.5 mm in size, were tested. All testing was performed using an Eriez Laboratory ESC, Model REA, fitted with 2000 gauss, surface field strength magnetic rotor. The belt speed was set to 91 meters per minute and the rotor speed was set to 2500 rpm in the forward direction. The splitter was adjusted to just reject the largest pieces of rock that measured an average 76 mm x102 mm x 127 mm. Based on the results of this limited test work, it can be recommended to placer gold mine operators, that Eriez Magnetics ECS technology is a viable and practical concentration technology for coarse gold recovery. Silver and platinum were also tested.

Jan 1, 2003

By Leigh Freeman

This article provides an overview for a series of leadership development workshops offered through the SME Young Leaders Program. The first of these workshops, “Accelerated Development Plan,” will be held at the upcoming SME Annual Meeting in St. Louis, MO on Sunday, March 26. How does a foundation of technical competencies relate to the development of social competencies necessary for management and leadership roles in the resource sectors? Technical competencies provide the foundation for a successful career. Social competencies provide the framework on that foundation. Successful leaders will be those who develop competencies in all areas.

Jan 1, 2006