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By Robin Burgess-Limerick

The introduction of automation to mining has great potential to reduce safety and health risks by removing people from hazardous situations. However, automation changes the tasks performed by people and may introduce new tasks. For the system to function optimally, these tasks must be designed taking human abilities and limitations into account. Humansystems integration refers to systems engineering processes that ensure that human-related issues are adequately considered during system planning, design, development, and evaluation. During procurement of automated systems, a human-systems integration program plan should be prepared that describes the human-systems integration activities that will be performed to address each of the six core domains of human-systems integration: staffing, personnel, training, human factors engineering, safety, and health.

Jun 16, 2020

By Robert Smith

Deposits are global, said Barrick Gold's Smith. This means that the mineral industry, by necessity, is global. "Manufacturers have considerable freedom to decide exactly where they wish to produce whatever it is that they sell," he said. "What we sell, on the other hand, must be produced where nature chose to lay it down. The question is not so much, whether to go global, as when to do it and how to go about it." The timing of international expansion depends on external factors, often political, Smith said, and on internal ones that relate to the company's size and stage of development. "In deciding how to expand, a company is largely deciding how to adapt its existing business strategy to activity on the world stage," he said Barrick entered 1997 with 1.58 kt (51 million oz) of reserves, Smith said, annual production of 93.3 t (3 mil- lion oz) and cash flow of $463 million. Reserves in- creased 40% in 1996 and production will begin to rise again significantly in 1999. "We believe our fundamental strategy is responsible for our early development and subsequent success," he said. Barrick entered the gold-mining industry in 1983. Its corporate mandate was to create shareholder value, Smith said. From the beginning, the company took a different approach - businesslike, entrepreneurial, strategic and focused. "Many mining companies start out with a technical team and develop business and financial expertise thereafter," Smith said. "In 1983, Barrick had the business people, and then moved into mining." First, it acquired part interest in two small operations, one in Alaska and one in Ontario. Then, in 1984, it merged with Camflo Mines, which operated a low-cost underground operation in Quebec.

Jan 1, 1997

By Galymzhan Karamyrzayev, Rashid Nadirov

Zinc ferrite ( ZnFe2O4) is a by-product of non-ferrous metal production and is considered a promising source of raw zinc. The most efficient way to extract zinc from its ferrite is via acidic extraction, specifically leaching by hydrochloric acid. A comparative study of synthetic zinc ferrite hydrochloric acid leaching in isopropanol, aqueous, and the mixed solvent was performed. Zinc ferrite was obtained by sintering a zinc and iron (III) oxide mixture. Crushed samples were subjected to leaching in 1 M HCl at 323, 333, and 353 K and pulp density of 1 g/100 mL. The dissolution of zinc and iron into solution in organic media reached 77% at 353 K, while in an aqueous environment this value was 65%. The activation energy of 70.0 kJ/ mol was found for the leaching process in an isopropanol environment, which is lower than that in an aqueous solution by 15%. The more efficient leaching effect of isopropanol is attributed to the lower dielectric constant of the alcohol which increases the affinity of chloride anions for zinc and iron cations at leaching.

Jun 5, 2022

By P. T. Bissert, L. Yan, J. R. Srednicki, J. A. Yonkey

"Refuge alternatives (RAs) are required in underground coal mines to support life post-disaster. RAs are mandated by MSHA to maintain an apparent temperature (AT) at or below 95°F (35°C) while providing a safe and livable shelter for a minimum of 96 hours. Because strata composition and mine temperatures will affect the final AT within an occupied RA, NIOSH researchers have collaborated with five underground coal mines across the US to characterize the effects of geographic location and seasonal temperature fluctuations on mine air temperature, relative humidity, and mine strata temperatures. The data collected indicates that some mines will experience greater temperature fluctuations than others, based on geographic location. The mine which demonstrated the greatest temperature differential over the course of the year resulted in a mine air temperature that ranged from 53.4°F (11.9°C) to 84.2°F (29.0°C) and a rib surface temperature that ranged from 55.4°F (13.0°C) to 82.8°F (28.2°C). This data suggests that the location and seasonal peak temperature can significantly affect the mine strata temperature, which could lead to a fully occupied RA exceeding the 95°F (35°C) AT limit over the course of 96 hours. The data reported in this paper could be used to examine the heat buildup inside an RA for actual mine conditions. Thermal simulations could be implemented to evaluate maximum occupancy ratings based on actual mine temperatures and strata compositions. INTRODUCTION In the event of a mine disaster, miners’ primary focus is to escape. Should their attempt be futile, they can enter a refuge alternative (RA) to await rescue. In 2008, the Mine Safety and Health Administration (MSHA) mandated that underground coal mines implement RAs within 1,000 ft (304.8 m) of the working face and spaced within one-hour travel distances in outby areas where persons work such that persons in outby areas are never more than than a 30-minute travel distance from an RA or safe exit. These RAs are required to provide a safe and habitable shelter for a minimum of 96 hours and to prevent the apparent temperature (AT) from exceeding 95°F (35°C) [1]. There is concern throughout the industry that in some cases the internal ambient of occupied RAs may exceed the 95°F (35°C) AT limit due to the potentially hot mine atmosphere as well as the metabolic heat generated by RA occupants and the carbon dioxide scrubbing system. The National Institute for Occupational Safety and Health (NIOSH) has conducted tests in its Safety Research Coal Mine (SRCM) and its Experimental Mine (EM) to investigate heat buildup in RAs. It was found that the number of occupants in an RA may need to be reduced based on the ambient mine temperature, which varies from mine to mine [2]. Further testing and analyses were completed to evaluate the mechanisms (conduction, convection, radiation) by which heat is transferred from an RA to the mine surroundings. Additionally, the effects of varying mine strata compositions on the heat buildup inside an RA were studied [3]. The mine strata temperatures will increase due to heat transfer from within an RA. Depending on the mine strata composition, some mines may be more thermally conductive than others. For example, sandstone is much more conductive than shale or coal (i.e. it disippates heat at a quicker rate). All things being equal, the air temperature inside of an RA after 96 hours will be higher for a mine with strata that has low thermal conductivity compared to a mine with high thermal conductivity."

Jan 1, 2017

By C. Zhou, C. C. Jobes, J. H. DuCarme

"Magnetic proximity detection systems (PDSs) are used with continuous mining machines (CMMs) to protect miners from striking and pinning accidents. Generators are used in a PDS to create magnetic fields covering the space around a CMM. The PDS determines the proximity of a miner relative to the CMM based on the magnetic flux density detected by a miner-wearable component (MWC) and simultaneously alerts the miner and stops the motion of the CMM if the miner is within a proximity that creates a striking hazard. A stable magnetic field is essential to the accuracy of the proximity calculations performed by the PDS. This paper presents the results of a systematic study of the magnetic influence of two types of steel structures found near a CMM—the body of the CMM itself and the wire mesh used for roof and rib control. The results show that the steel of the CMM body can change the magnetic field distribution and also alter electrical parameters of a PDS by changing its generator current. The study also shows that, depending on the distance between the wire mesh and a generator, the magnetic field can also be altered. INTRODUCTION Continuous mining machines (CMMs) can be up to 10 m (33’) in length and more than 3 m (10’) in width. These machines perform the coal cutting operations in underground room-and-pillar coal mines. Accidents during CMM operation accounts for an average of 250 injuries every year, and 43 miners have been killed by striking or pinning accidents involving CMMs in the United States from 1984 to 2015.Because of these fatalities and injuries, the Mine Safety and Health Administration (MSHA) promulgated a regulation in 2015 that requires the use of proximity detection systems (PDSs) on all CMMs with the exception of full-face machines (Mine Safety and Health Administration, 2015). Currently, there are five different proximity detection systems that MSHA has approved as permissible for use in U.S. underground coal mines (Mine Safety and Health Administration, 2013). All of these PDSs rely on a miner-wearable component (MWC) to detect the generated magnetic fields that PDSs produce around a CMM (Schiffbauer, 2002). These systems use the magnetic field strength readings in terms of magnetic flux density from the MWC to determine whether a miner is at a safe distance from the CMM. A stable magnetic field is essential for the accuracy of a PDS."

Jan 1, 2018

By Brian Y. Lattimer, Kray D. Luxbacher, Jonathan L. Hodges, Manuel J. Barros-Daza

The abstract discusses the importance of predicting fire response time (the time before conditions become untenable for firefighters) in underground coal mines. It introduces a data-driven approach using artificial neural networks (ANNs) to predict response time and fire size based on measurable parameters like CO concentration, mine geometry, air velocity, and time since fire detection. The approach was tested using simulations from fire models (FDS and FSSIM), showing promising results for real-time predictions during mine fires.

Mar 6, 2022

By H. Kimura

A new technology for ironmaking based on direct gaseous reduction of iron ore concentrate is under development. The process is based on the flash reduction of the concentrate particles in a gaseous reducing agent, such as hydrogen, natural gas, a reducing gas generated by partial combustion of coal, or a combination thereof. This technology is expected to drastically lower CO2 emission and reduce energy consumption by about 38% of the blast furnace requirements. The energy savings are possible largely due to the elimination of pelletization and cokemaking. Process design and simulation using hydrogen as the reductant for iron ore concentrate have been performed. A process flow sheet composed of a flash reactor, heat recovery system, water removal system for purifying recycled hydrogen, and all connecting streams was evaluated using the METSIM software. Ironmaking using two reactors was also designed and simulated, which could reduce the total required amount of hydrogen although it would increase the complexity of the flow sheet and operation.

Jan 1, 2010

By C. Stacy

The mining industry is changing rapidly. Competition among OEM and aftermarket vendors increases dramatically each year as a result of mergers and acquisitions, and especially technology advancements in the mining industry. Adding value to mine operations by delivering technical value and differentiation is becoming more subtle and more difficult to accomplish. Because of this, identifying and protecting intellectual property has become more important to the product development, engineering and marketing/sales continuum than it had been in the past. How companies protect intellectual property and determine the value of those assets is critical to the sustainability and differentiation of technology providers in the mining industry.

Jan 1, 2012

By I. M. Ahmed, R. S. Hassan, M. I. Aly

Extraction and separation of La, Sm and Dy ions from acidic sulfate-phosphate solutions was investigated using a cation exchange extractant, bis(2,4,4-trimethylpentyl) phosphinic acid, CYANEX 272, in kerosene. The influence of shaking time, equilibrium pH, extractant, sulfate and phosphate ion concentrations, diluent type and temperature was studied. The extraction was found to be pH-dependent, and increasing the phosphate ion concentration inhibited the extraction which was found to be endothermic. The stoichiometry of the extracted metal species was found to be MOH.H2OHSO4H2A.A2. Aliphatic diluents were found to enhance the extraction compared to aromatic diluents. The results showed that there was a separation mode between the metal ions when varying the hydrogen ion and sulfate ion concentrations, under the used experimental conditions. The investigated process was used for the recovery of La, Sm and Dy from the acid solution resulting from the leaching of low-grade monazite.

During the past 20 years, FKC-Lake Shore, located in southern Indiana, has been working with Contitech, the German conveyor company, to push vertical conveyor technology to new depths and open up additional opportunities for underground mine owners. Historically, the underground mining industry has largely been unable to realize the benefits of these efficient systems due to the design limitations in maximum depth and capacity. Until recently, only relatively shallow depth mines with low production rates have been a ?t for a vertical conveyor system. This, however, is changing with technical advancements in the Pocketlift system. With each milestone, a new vertical conveyor record is set for depth and capacity. For instance, in 2002, FKC-Lake Shore set one such record with the installation of a Pocketlift system at a mine in the Illinois coal basin with a lift height of 273 m (896 ft) and a production rate of 1.8 kt/h (2,000 stph). Although it was unthinkable at that time, today?s vertical conveyors are capable of reaching lift heights up to 700 m (2,300 ft) with an average production rate of 450 t/h (500 stph). These new lift heights and production rates are opening the technology to more potential mine owners and shifting the way people look at moving material in the future.

By A. Simon, J. Weyer, J. Brune, V. Zhiteneva

"Reiche Zeche is a lead-zinc-silver deposit in Freiberg, Germany, that was mined for over 800 years. Since 1969, Reiche Zeche has been a teaching and research mine with numerous adits for dewatering large amounts of inflowing water. Infrequent metal water quality monitoring in the 1980-1990s and flooding of the mine in 2002 led to a lack of relevant data. New measurements were taken at different level adits and ore veins for comparison to historical values, revealing pH levels as low as 1.95, conductivity as high as 22000 µS/cm, and an overall trend towards less acidic waters. INTRODUCTION Reiche Zeche is part of the Himmelfahrt Fundgrube, a former iron ore mine in Freiberg, Germany, in the Erzgebirge mining region of Saxony. The polymetallic sulfide ore found in Freiberg was mined from 1168 to 1969, and though it is no longer producing ore, Reiche Zeche remains as a teaching and research mine for the Technische Universität Bergakademie Freiberg. The most important ore minerals mined were sphalerite, galena, pyrite, chalcopyrite, and silver, and important gangue minerals include calcite, fluorite, barite, siderite, and quartz (Zänker et al 2002). Over one thousand ore loads were mined from this region during operation, which was ceased in 1969 after the lower part of the 700 meter depth was flooded, leaving only the top 200 meters under the surface open for research and teaching. Mined materials from this region can be separated into high grade ore and waste rock. High grade ore, composed of pyrite, sphalerite, galena, chalcopyrite, and arsenopyrite, was brought to surface for smelting during mine operation, and spaces were backfilled with waste rock, which is the primary site of sulfide oxidation and acid mine drainage (Haubrich and Tichomirowa 2002). The waste rock includes remnants of ore from ore loss, veins which were too small to mine, or ore minerals within host rock. Waste rock is primarily composed of biotite gneiss, with sulfides including jarosite, gypsum, minor anglesite, scorodite, and sulfur (Haubrich and Tichomirowa 2002). When weathered, the gneiss forms clay minerals such as illite and kaolinite (Haubrich and Tichomirowa 2002)."

Jan 1, 2016

By Claus Becker

The new, 2.600 m long pipe under the river Elbe in Hamburg/Germany required for 2 traffic lanes, emergency lane and space for utilities a boring diameter of 14,20 m(46,6 ft). According the geology (glacial deposits consisting of clay, sand and marl, all containing big boulders) a Slurry-Shield with crusher was selected. With a minimum cover of 7 m and a maximum pressure of 5,6 bar extensive ground treatment was necessary to make the drive feasible. The machine contains a lot of new developments. The drive was finished in spring 2000 so all experiences can be reported. A special risk sharing contract avoided completely litigation.

Jan 1, 2001

By Fabio Mielli

The mining industry is a multifaceted industry with special characteristics that make efficient and intelligent operations uniquely challenging, and subsequently call for distinctive and tailored solutions. Not only does mining call for processes that are complicated and energy intensive, but complex material movements and an intricate logistical chain add to the industry?s obstacles in achieving sustainability and performance. This article explores three major challenges and the resulting issues currently being faced in the industry, as well as potential solutions to these impediments by use of energy management, automation and control strategies.

Jan 1, 2011

By Gregory M. Rumbaugh, Todd Kostecki, Christopher Mark

From 2015 to 2021, five massive pillar collapses occurred at four underground stone mines in the eastern United States. These events resulted in powerful airblasts that damaged mine infrastructure and mobile equipment, seriously injured miners, and disrupted underground travelways. Each of these pillar collapses propagated through the overlying strata, causing a subsidence basin on the surface. Pillar collapses are particularly hazardous for miners because they can occur with little warning and can affect miners that are far from the pillar collapse area. The following case studies show that certain factors may increase the likelihood of a pillar collapse. For instance, each of the five events involved the collapse of at least twelve benched pillars with width-to-height ratios (w/h) of 0.8 or less. This study elaborates on

By K. M. O’Connor

Time Domain Reflectometry (TDR) is a pulse testing technique developed by the telecommunications and power industry for use in locating breaks in cables. Variations of this principle have been utilized in applications pertinent to closure and reclamation of coal operations. This paper focuses on applications of TDR technology in the mining industry including monitoring of slope movement, abandoned mine subsidence, ground water levels and subsurface LNAPLs, landfill cover performance, and consolidation of mine tailings. TDR technology has been particularly effective for remote automated monitoring, and alarm systems have been implemented for monitoring subsidence.

Jan 1, 2003

By P. Rosario

During the last few years high-tonnage plants have been designed with comminution circuits using semiautogenous grinding (SAG) mills, high pressure grinding rolls (HPGR), or both, followed by ball mills in different configurations. A strong interest in improved energy efficiency and reduction of carbon footprint, along with the recent launch of new high-capacity crushers and stirred grinding mills, has driven the industry to investigate the development of novel flowsheets. This paper presents work based on recent projects that include modeling and simulation of two innovative circuits recently considered for current projects. One circuit uses autogenous (AG) mills and parallel trains of crusher-HPGR and the other is a modified three-stage crushing circuit with the use of HPGRs and pebble mills. The paper indicates the potential savings in operating costs provided by the HPGR-pebble mill circuit when compared to a more conventional SAG-mill-based circuit.

Jan 1, 2010

By Ying Lu, Jeffrey C. Johnson, Chen-Luh Lin, Jan D. Miller, Sindhoora Puvvada

Energy dissipation and fragmentation of rock is of interest for mine-to-mill operations in order to understand breakage and to minimize energy consumption during blasting at the mine site, and comminution at the processing plant. In this regard, high velocity impact breakage of long granite cores, called bars, has been studied with instrumented strain gages to follow the energy dissipation gradient along the bar length resulting from the strain waves generated by impact. As a result of high velocity impact, three zones have been identified (fragmentation, fracture, and elastic) and these three zones have been characterized in 3D using X-ray tomography. The fragmentation zones of the granite bars were studied in detail to describe the particle size distribution and the particle shape characteristics. Finally, the experimental energy dissipation for the fragmentation zone was found to be in close agreement with the expected energy calculated from the Bond work equation, if the anisotropic granite particles are defined by length rather than by sieve size.

By L. Adler

To mine safely and efficiently the working conditions must be systematically de¬fined. Their uniqueness distinguishes mining from other engineering professions. The worst case in underground mining is delineated and termed "encumbered space'", since it "seriously impedes motion or action." Working space is inherently hazardous, transitory, and expensive, inducing it to be of low quality, tight and congested, vulnerable and deteriorating, and isolated and inaccessible. These adverse conditions, are damaging to cumbersome, mobile equipment, and affect all activities, including surface work. The conditions are reorganized using the fundamental engineering dimensions: space, matter time, people, and money. Comprehensive tables are presented with attention paid to "disaster potentials". Examples are cited.

Jan 1, 1982

By W. J. Schitt

Section 15 covers a loose collection of topics that involve water in some way. The chapters in this section include Dredge and Placer Mining (Chapter 15.1), Solution Mining: Surface Techniques (Chapter 15.2), and Solution Mining: In Situ Techniques (Chapter 15.3). The dredge and placer systems involve water in several forms. The segment on hydraulicking or hydrosluicing discusses the use of monitors to direct high-pressure water jets to move material. As such, this represents an alternative to mechanical breakage, loading, and hauling. This chapter also covers placer mining (except dry placering) where the water provides the medium that promotes the separation of minerals based on their density and other settling characteristics. Thus placer mining is generally limited to concentration of gold, tin ore, diamonds, and other heavy minerals that are already liberated and are contained in a less dense matrix. The third topic, straight forward dredging, as in sand and gravel operations, involves water only in an incidental way. Here water simply covers the minerals of interest. Thus the dredging system need only lift a payload from the submerged location to the surface for further processing or handling

Jan 1, 2008

By T. Faulkner, S. A. Richards

"Classic engineering economics provides the mining engineer with a fundamental approach to choosing between capital spending alternatives. This approach has been heavily used over the years and is an accepted technique for most investment decisions. There is a shortcoming that I have run into over the 15 year period when I worked in business planning roles. The classic time value of money approaches such as Net Present Value, Return on Investment, and Internal Rate of Return provide good estimates, but the input assumptions may fall short of describing the real material differences required by these analysis techniques. If the cost benefit analysis is defined solely on the improvement of the item being replaced or improved, the true profitability of the decision may be overestimated. Productivity improvement based capital projects can yield more accurate forecasts when conducted in concert with a “bottleneck analysis”. INTRODUCTION A review of the Theory of Constraints, (Goldratt, Cox, 1984) Lean, (Womack, 2003) (Rattner, 2006) and Six Sigma (Cryger, DeFeo 2015) lead us to recognize that these process improvement methodologies are oriented to the manufacturing process. These systems generally involve a factory that the material moves through on the way to becoming a final product. The mining challenge has many similarities to manufacturing once the ore has been won and made ready for processing. Before that point, however, the process is somewhat inverted while the ore is being won. Instead of the material moving through the factory, the factory is moving through the material. The Theory of Constraints (TOC) was used in an underground context by Baafi, Cai and Porter at 2015 APCOM, but even this groups’ analysis did not carry the concept from mining to shipping of the final product. There can be spatially distributed data that can affect the mining throughput constraints, some of which can be determined from exploration results. Identifying constraints can lead us to mapping productivity bottlenecks on future mining. Knowing this may improve decision making by eliminating one of Jim Fishbein’s three deadly sins of strategic planning: incomplete planning. When evaluating capital investment alternatives you should evaluate the impact of any proposed improvements on the entire operation. At the core of any mining system is the materials handling system. This can be typically expressed as the system that handles the raw material from the “face” through processing and then handling the finished product as well as the waste material. A “Bottleneck Analysis” is an investigation into the factors limiting a material handling system’s productivity (Goldratt, Cox, 1984). Mining material handling systems are usually composed of several linked components such as draglines, shovels, loaders, hydraulic excavators, continuous miners, longwalls, highwall miners, bucket wheel excavators, LHDs, feeders, conveyor belts, stockpiles, crushers, processing plants with various circuits, and waste handling systems. Each of the aforementioned components has a slightly different throughput capacity. When these are linked in series, the one with the lowest throughput capacity limits all of the others, creating the bottleneck for the system. Every material handling system has a bottleneck. In the mining environment, a subtle, but very significant phenomenon may also occur. The bottleneck may change as a result of a change in the raw feed qualities, face recession, overburden depth, digability, learning curve, and many others factors which may be derived from the drillhole data. These parameters often change as a function of the location in the reserve base, and may also vary with time."

Jan 1, 2016