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By A. Unal

Barbaro et al. (1990) implemented a tedious study aimed at delineating the short-scale spatial variability of sulfur in a coal seam. It is not possible, however, to extend their conclusions to any other coal seam or use theirs in any other fashion, because the background geology was not presented. Nor were the conclusions accompanied by geological interpretations in the paper. In addition, an unfortunate printing error occurred where the total sulfur (determined by High Temperature Combustion) variogram in Fig.3 was duplicated in Fig. 2 instead of the seam height variogram. A more serious error, however, has been committed in the definition of the variable, seam height. What is defined as seam height by Barbaro et al. (1990) is, in essence, mining height, and is not a regionalized variable that should be studied by geostatistical methods directly. Despite the fact that the variable, seam height, is not defined in the paper explicitly, the following quotation discloses the fallacy: "All roof rock that exceeded 1.8 m (6 ft) from the floor was not taken because the longwall was operated to not mine more than 1.8 m (6 ft) unless the coal seam height exceeded 1.8 m (6 ft)." From this definition, the seam height, and therefore the sampling height, is equal to the actual coal thickness, if the coal thickness is greater than 1.8 m (6 ft). Otherwise, it is equal to the sum of the coal thickness plus the thickness of the roof rock that complements the thickness to 1.8 m (6 ft). In the latter case, the seam height is constant and equal to 1.8 m (6 ft). It is possible to conduct a variogram study on a pool of samples that are realizations of two different variables. But the conclusions derived would not belong to any one of the two variables uniquely and, therefore, do not possess any significance. Geostatistical analysis is irrelevant for the sum of multiple regionalized variables formed by arbitrary selections. In a two¬seam setting, for example, the mining height, as defined by the thickness of one seam at one location and the thickness of both seams at another location (due to quality and/or minimum thickness considerations perhaps), should not be used in the calculation of one common variogram. The two seams should be modeled separately. They can then be combined according to the specific purposes of the study. On the other hand, if a constant is added to a regionalized variable (to incorporate dilution perhaps), the variogram of the new variable will not change. Barbaro et al.( 1990), surprisingly, does not give any geologi¬cal interpretation of their results despite the fact that most of them can be explained by the origins of sulfur in a coal seam. The presentation of the results of a geostatistical study with no reference to the geology of the deposit is uninformative. It may also be misleading for the potential users of geostatistics. It is not unusual to find nuggets of pyrite in coal seams. In such cases, pyritic sulfur will probably display a spatial structure for only a very small distance that will appear in the experimen-

Jan 1, 1991

By R. M. Schuster, F. M. Benavides

Samuel G. Bonasso The article by Benavides and Schuster provides an in-depth study of three transportation alternatives for a four-mine complex in western Kentucky. The examination of aerial tramways was not undertaken as an alternative solution. We feel this is an oversight since industrial ropeways are competitive with both belt conveyance and overland truck hauling. In fact, there are aerial tramway systems, operational today, which are 100 years old and operating with some original components. Maybe unfortunately, there are no fixed rules or guidelines whereby the most cost-effective means of transporting and handling material for a given situation may be selected. Each situation must be evaluated so the variables that influence the selection of the desired alternative can be clearly defined. However, there are in-place industrial ropeway systems that have proven economically feasible over a range of 1.6-50 km (1-31 miles). The more difficult the terrain, the greater the cost efficiency.

Jan 1, 1983

By Xiaodong Ma, Marek Pawlik

Introduction Guar gum is a natural nonionic polysaccharide. Guaran, the functional polysaccharide in guar gum is a chain of (1?4)-linked ß-D-mannopyranose units with a-D-galactopyranose units connected to the mannose backbone through (1?6) glycosidic linkages. The poly-mannose chain is randomly substituted with galactose units at a mannose-to-galactose ratio of 1.8-1.0 [1]. Cheng et al. reported that the molecular weight of natural guar gum is 1.935 • 106 [2]. Robinson et al. found that the molecular weights of five grades of commercial guar gums ranged from 4.4 • 105 to 16.5 • 105 [3]. Guar gum is frequently used as a depressant of naturally hydrophobic gangue minerals (e.g. talc) in the flotation of PGM-bearing ores, and according to Harris et al. a wide variety of modified guar gums are available for this application [4]. The Canadian potash industry utilizes natural guar gum as a blinder of water-insoluble slimes in the flotation of potash (sylvinite) ores, a process that is carried out in a saturated KCl/NaCl brine. The role of the polysaccharide is to prevent a primary amine collector from adsorbing onto these unwanted fine minerals. Hydrophobic interactions between basal cleavage planes and the polymer appear to be involved in guar gum adsorption on talc [5,6]. Liu and Laskowski stressed the importance of metal impurities on mineral surfaces that can serve as the active sites for polysaccharide adsorption [7]. This postulate was consistent with the later observation that, in addition to hydrogen bonding, the adsorption of guar gum onto talc was strongly dependent on the surface concentration of magnesium sites [8,9]. In this case the adsorption process was visualized as metal-polysaccharide complexation facilitated by the cis-configuration of the hydroxyl groups of mannose monomers. Hydrogen bonding and chemical interactions with metal sites were also suggested by Rath and Subramanian in their studies on guar gum adsorption on biotite mica [10]. In a recent study, Wang et al. demonstrated that hydrogen bonding is the main driving force behind guar gum adsorption onto talc [11]. Their data also show that the adsorption density of guar gum on alumina is about five times lower than the adsorption density on talc. Pawlik and Laskowski reported that the amount of guar gum adsorbed on illite was independent of ionic strength over a wide range of salt concentrations [12]. The adsorption density of the polysaccharide on illite did not measurably change with ionic strength from that of distilled water to about 50%-saturated KCl/NaCl potash brine (~3N KCl/NaCl). However, guar gum adsorption on dolomite dramatically decreased over the same range of ionic strengths, and no reliable explanation of that phenomenon was proposed [12]. The water structure-breaking or structure-making capabilities of background ions are usually ignored when discussing adsorption mechanisms of polymers. The concept of “structure breakers” and “structure makers” was first introduced by Gurney, and Frank and Wen who postulated that each ion is surrounded by three distinct regions of water structure [13,14]. In the first layer, water molecules are tightly bound to the ion. The second region extends farther away from the ion and is referred to as the region of structure breaking. Only at larger distances, where the ionic field is weak, water molecules form the “normal” ice-like structure. It is also now recognized that the first layer can be further divided into the primary and secondary hydration shells. Small, strongly hydrated ions reinforce the “normal” structure of water and the region of structure breaking disappears. In contrast, large less-hydrated ions disturb the ice-like structure and generate an extensive region of structure breaking. Experimentally, these two effects can readily be distinguished through viscosity measurements. Increasing concentrations of structure-breaking ions result in a decrease of the viscosity of aqueous solutions. On the other hand, increasing amounts of structure-makers significantly reduce the viscosity of water. Alkali metal cations form a sequence known as the Hofmeister series. The Hofmeister series - Cs+, K+, Na+, Li+ - orders the cations from the least hydrated to the most hydrated. Based on literature viscosity data for aqueous

Jan 1, 2005

By B. A. Wills

Much research effort has been spent in attempting to reduce the high energy costs in grinding, but relatively little in developing methods to enhance the liberation of the minerals from each other. This paper presents some ideas on the nature and role of grain boundaries in mineral assemblies, and their influence on the propagation of cracks through the rock. It is argued that if the mechanisms of fracture are more clearly understood, crack propagation may be controlled in such a way that intergranular fracture dominates breakage, producing less fines and a higher degree of liberation.

Jan 1, 1995

By Tim O’Neil

Dressed in black tie and Victorian attire, some 200 people came to Leadville, CO, for a September weekend featuring a National Mining Hall of Fame and Museum (NMHF&M) induction banquet and a scenic mountain train trip to Fremont Pass and the Climax Mine. The 18th annual induction banquet on Sept. 17 began with cocktails and a open house. It was a chance for visitors to tour the National Mining Museum including the new Hennebach Wing, opened in February. The new wing is named in honor of Ralph Hennebach, retired chairman of Asarco. Formerly Leadville Junior High School, the Hennebach Wing encompasses more than1,440 m2 (15,500 sq ft) of floor space in two stories. One prominent feature is a 1923 Wills Sainte Claire touring sedan. Climax Molybdenum donated this first all-molybdenum steel motorcar. Docents were available throughout the museum to give banquet attendees directions and answer questions.

Jan 1, 2005

By R. Mira, S. Rosa, P. Souza

This paper shows the historical data, local geology and mineralization, the mining methods applied, current production,, the planning staff, the resources of hardware and software available and the computer methods used. The activities are described starting with the driving of ramps/research levels, their dimensional parameters and positioning, driving of production sublevels with the same parameters plus those concerned with the stability of the rock mass during the development and the mining itself. Then, the detailing of the ore body is described together with the stopes planning, the openings stability analysis, and the drilling patterns and explosive types are discussed.

Jan 1, 1998

By Odin D. Christensen

Gold deposits of the Carlin Trend occur within sedimentary rocks deposited across the Paleozoic continental margin. Lithologically dissimilar units, juxtaposed along the Roberts Mountains Thrust Fault system, constitute three distinct stratigraphic packages: autochthonous miogeoclinal carbonates, allochthonous eugeoclinal siliciclastic rocks, and an overlying coarse clastic overlap assemblage. Gold deposits occur within all three stratigraphic packages, with economic concentrations localized at structural and stratigraphic settings similar to those which host petroleum traps. Along structural breaks, gold is selectively concentrated within favorable stratigraphic units. Host stratigraphy controls the character of the ore, including average grade, grade variability, physical properties and metallurgical response.

Jan 1, 1989

By Dennis P. Martin, Michael M. Fitz, James E. Friant

Methods for reducing the cyclic nature of drill and blast tunneling operations have been long needed. A miniature blasting system using 10 mm (.375 in.) holes, 0.91 m (36 in.) deep, and blasting only one hole at a time makes it practical for men to work behind a shield, remaining at the face during the entire process. A prototype automated module was developed to drill, load the hole and initiate the detonation without moving from the hole. A unique cost effective gell explosive and a novel, low cost initiation method were developed.

Jan 1, 1989

Diesel Particulate Matter (DPM) is considered carcinogenic after prolonged exposure. With increasing use of diesel-powered mining equipment in underground mines, miner?s exposure to DPM has been increasing. Most studies on the issue has been DPM control measures with few studies on diesel exhaust propagation patterns after leaving the tailpipes. This study uses computational fluid dynamics (CFD) to investigate the airflow pattern in an underground metal/nonmetal mine for a single heading. Several high DPM concentration areas are identified in the study and common practices for compliance are suggested. Airflow and DPM distribution are compared between blowing and exhausting face ventilation systems. Suggestions are also provided for the protection of miners in the face area.

Jan 1, 2009

By N. T. Cowper

Slurry viscosity ultimately affects the majority of mineral extraction processes. However, to date its role has been disguised because mineral processing equipment has been conservatively designed to operate at minimal slurry viscosity. With most ores this still meant acceptable solids concentration was achieved. However, with the advent of treatment of weathered ores the resulting higher slurry viscosity (rheology) has meant solids concentration has had to be reduced, often to unacceptable levels. To permit operation at higher solids concentration chemical dispersants are employed. These dispersants are expensive and their addition should be controlled. Slurry Systems Pty Limited (SSPL) has developed an On-Line Viscometer to monitor and control slurry viscosity, whether by controlling water addition or by controlling dispersant addition. Using this instrument the slurry rheology can be controlled at the optimum level, maximizing solids throughput, and minimizing water, reagent, and dispersant addition. This paper discusses rheology of typical mineral slurries, the relationship between slurry rheology and percent solids in a slurry, and the need for rheological control in mineral processing. The effects of rheology on various process steps, and the use of dispersants are reviewed. The paper concludes with summarizing actual case histories and cost impact of Theological control.

Jan 1, 1992

By Jon A. Hummer, Aleksandar D. Bugarski, Shawn Vanderslice, Teresa Barone

Reducing the contribution of heavy- and light-duty diesel-powered equipment to concentrations of aerosols and gases is essential to industry’s efforts to improve air quality in underground mining operations. The results of this study demonstrated a potential of control strategies based on retrofitting existing power packages with diesel oxidation catalyst (DOC) and diesel particulate filter (DPF) systems and repowering existing systems with advanced power packages to reduce contributions of diesel-powered vehicles to concentrations of diesel aerosols and criteria gases in underground mines. The implementation of viable exhaust aftertreatment systems and advanced diesel power packages could be instrumental in the underground mining industry securing a clean, economical and dependable source of power for mobile equipment.

By Kerry Spickelmier

Editor's note: information for this feature was taken from the published APCOM proceedings. Computer trends, with special focus on the reasons for computer use, grabbed the lion's share of attention at the 23rd worldwide meeting on the Application of Computers and Operations Research in the Mineral Industry (APCOM 23). However, technical topics did not provide the meeting's sole focus. The last-minute inability of certain former communist countries to fund the travels of a few scheduled speakers was a reminder that science does not operate in a void. As with all technical progress, the APCOM presentations raised interesting questions regarding interrelated organizational dynamics and political and socioeconomic issues. Consider US Bureau of Mines (USBM) research to design an expert control systems to "duplicate" an experienced, "good" operator during automated underground roof bolting. In his presentation of the project, Takach, Jr. stressed the importance of preserving the ability to switch from automatic to manual drilling control. From a technical standpoint, this allows the expert system to "learn" from a good operator. As important, he said, is that this flexibility decreases the human operator's sense of being replaced by the machine. The question arises: Which will loom larger in union minds, increased operator safety through remote opera¬tion or the potential for total operator replacement? Like any new product, computer technology relies on marketing to aid its acceptance and use. Consider, too, a decision support system, by Schena and Gochin, for mineral resource management in a developing country. The authors said "the analysis permits the assessment of the overall socioeconomic consequences of mineral prospects and allows incorpo-

Jan 1, 1992

By H. O. Seigel, John C. Robbins

Luminex is a new method of prospecting for mineral deposits based on time-resolved mineral luminescence created by an ultra-violet light source. Developed by Scintrex Ltd., Luminex detects and resolves a group of key minerals - either ore minerals themselves or, more often, accessory or pathfinder minerals for certain types of economic ore deposits. These minerals are commonly found on the earth's surface, even in areas of considerable weathering. The method extends the range of mineral deposits that are remotely detectable from the air. Tungsten, tin, molybdenum, gold, and bedded lead-zinc deposits are included. Therefore, Luminex is a natural supplement to the three classical methods of airborne geophysics. The luminescence of minerals has been known and used qualitatively in mineral exploration for many years. But there are more than 500 minerals known to be at least sometimes luminescent. Luminescence of most is unpredictable and the colors they emit may vary from locale to locale. It is, perhaps, this apparent complexity of the field that has discouraged its proper scientific scale until now. There are two basic types of luminescent minerals - intrinsic and impurity activated. In the first type, luminescence is an inherent property of the mineral in its purest form. In the latter, luminescence is due to the introduction of foreign trace elements, often in very modest amounts (ppm), into the crystal lattice. These trace elements are known as activators. There are very few intrinsic luminescent minerals commonly found in nature. Chief among these are the calcium tungstatemolybdate family, more commonly known as the scheelite-powellite family, and the uranyl minerals such as autunite and saleeite. The vast majority of other known fluorescent minerals such as fluorite, hydrozincite, and many calcites, are impurity activated - that is, they will not fluoresce in purest form. In addition to the many minerals likely to luminesce at the earth's surface under ultraviolet excitation, any prospector who has ventured out at night with a mercury lamp will know that much organic matter luminesces - for example lichens and even scorpions. Just as the eye finds difficulty in resolving the luminescence of minerals from that of organic materials, it also has its limitations at sorting out minerals from one another by their luminescent colors. Figure 1 shows, in part, the photoluminescent emission spectra of scheelite, hydrozincite, and autunite. It is clear that there is a considerable similarity in spectrum between scheelite and hydrozincite and a great deal of overlap. In fact, a small amount of molybdenum in the scheelite lattice can almost bring these two spectra into coincidence. On the other hand, the autunite emission spectrum is clearly resolved from the other two. Basis of the Method The right-hand side of Fig. 1 shows the time waveforms of decay of the photoluminescence of the same three minerals. It is apparent that the lifetimes of photoluminescence of scheelite and hydrozincite are radically different and that these two minerals, therefore, may be readily resolved through their emission lifetime characteristics. It is in the realm of time-resolved measurements (lifetime characteristics) that Scintrex has made its major advance in the Luminex method. With the exception of some work by Exxon confined to uranyl minerals, to the best of our knowledge, no systematic scientific investigation has been carried out in the field of time-resolved mineral luminescence studies other than the work of Scintrex. Scintrex's findings are that all organic materials and most commonly activated luminescent minerals have lifetimes shorter than one microsecond. In addition, only a relatively small number of minerals - among them those called key minerals, or certain ore and pathfinder minerals - have lifetimes greater than one micro-second. Scintrex is able to characterize these minerals primarily by their emission lifetimes and secondarily by their emission spectral characteristics. By a combination of these factors a mineral index is arrived at. From that, photoluminescent minerals can be resolved from one another with a high degree of probability. At least two spectral channels and two time channels - of which one can be common - are required to apply this mineral index. Ground System A portable hand-held Luminex analyzer based on a modulated mercury lamp has been used to date in Canada, the US, and Australia. The current production model of this device is the LG-2. It has two spectral channels and two time channels for each spectral channel. Figure 2 shows a ground Luminex traverse over the Texas-Arizona zinc prospect in Arizona. The instrument was set so the channel read was hydrozincite-specific insofar as possible. The mineralization in this prospect is known to be hydrozincite and other zinc secondary minerals in limestone. Figure 3 shows a ground Luminex traverse over the AAA uranium prospect in Nevada. The instrument was set to optimize the uranyl response. For comparative purposes, broadband scintillation counter readings were made on the same stations (also shown in Fig. 3). It is apparent that both the Luminex and the scintillation counter results reflect a near-surface distribution of uranyl minerals. It is interesting that no visible uranyl secondary minerals

Jan 7, 1983

By Michael J. Martinson, John R. Larsen, J. Warren Andrews

Measurements reported in the paper were recorded in an active Green River, Wyoming, trona mine, partly as a teaching exercise and partly to provide the mine in question with additional input data for its ventilation network program. Measurements were made: - in representative three-entry intake airways in room and pillar sub-mains; - between the lower portion of a vertical down-cast hoisting shaft and the start of an intake airway system established in a room and pillar main; - in a representative downcast section of a divided vertical shaft, and of the collar entrance loss at the top of the same compartment. Pressure differences were measured with manometers and trailing hoses, air flowrates with calibrated anemometers, and barometric pressures and wet-and dry-bulb temperatures were recorded for density determinations. Where possible, results are quoted as Atkinson friction factors, and relevant measurements are recorded in some detail to show the magnitude of fluctuations in observed pressure differences.

Jan 1, 1987

By Steve Kral

President Bush’s National Energy Program and his Clear Skies Initiative both emphasize the use of coal to help meet the nation’s growing energy needs. And why not? Coal is currently responsible for more than 50 percent of the nation’s electricity generation. That fact, though, seems to be lost on policy makers, the environmental community and the public. Critics of coal advocate the increased use of renewable energy sources and the increased use of natural gas. Renewables, though, are only capable of generating a tiny fraction of the power required. Natural gas is expensive. And natural gas production cannot keep up with demand, especially given the nation’s increasing energy needs.

Jan 1, 2003

By M. Solomon

Crushers are designed and manufactured to survive the severe duty of mining environments worldwide. Under these conditions the crusher performance and availability is one of the critical factors in the mine?s production and profitability. Traditionally the development of these machines tends to be experience-based, incremental improvements in design due to challenges of different applications, duty, or manufacturing. In order to better serve the mining industry a new approach was taken to the design of primary crushers. This approach was to focus on safety and maintenance activities. The result of this effort is a new generation of gyratory crushers that can be serviced from above. Using the features of this new generation of crushers to their fullest extent crushing installations have improved safety, reduced design and construction costs, and lowered maintenance requirements. This presentation explores the benefits of two crusher installations utilizing top service crushers.

Jan 1, 2010

By Karl H. Bruemmer

1. TRENDS OF DEVELOPMENT IN THE MECHANICAL DRIVING OF UNDERGROUND EXCAVATIONS IN THE GERMAN COAL MINING INDUSTRY The demand for higher advance in underground excavations led, in the past ten years, to the development and application of various mechanical methods in the coal mining industry of the Federal Republic of Germany. Hence, a modern mine cannot operate anymore without tunneling machines for the driving of horizontal and inclined roads and shaft boring machines for the sinking of shafts. In future, boring operations will assume a high positional value in the mining industry, as the development of cutters has kept pace with the development of machines. In the past ten years, about 40 km of roadways have been bored by tunneling machines in the German coal mining industry, further 140 km will be bored by 1990, part of which are already under contract. The idea was tempting to apply the technology of horizontal tunnel borers also to the sinking of vertical shafts. The underground contractors Deilmann-Haniel GmbH of Dortmund and Thyssen Schachtbau GmbH of Mülheim/Ruhr developed already in 1970, together with Wirth of Erkelenz, a shaft boring machine working without drill pipes, capable of sinking shafts following a pilot borehole, according to the downward reaming method (Fig. 1). In the meantime, two such shaft borers are operating in coal mines with diameters of 4.50 m to 6.50 m. Recently an order was placed for a third Wirth shaft borer for diameters up to 8.50 m. Since 1971 about 3.800 m of open or blind shafts have been sunk by the reaming process (Fig. 2).

Jan 1, 1979

By Daniel Tempelis, Tom Freeman, Eric Fordham, John Shamma, Steven Duke

The Arrowhead Tunnels in southern California are being completed by MWD under stringent groundwater in?ow limits established by the U.S. Forest Service. Pre-excavation grouting, new TBMs and a bolted, gasketed, pre-cast concrete segment initial lining are employed to control water in?ows. The effectiveness of prescribed water control measures was analyzed using conservative assumptions with the analytical techniques described by Goodman (1964), Heuer (1995), and numerical modeling. Analyses results suggest groundwater in?ows to the tunnels can be maintained well below the limits with aggressive pre-excavation grouting balanced against a reasonable rate of advance and quality erection of the initial lining system.

Jan 1, 2003

By Ehsan Nasiri, Keivan Pak Iman

Historically, boulders are a frequent source of problem in soft ground tunneling. It is important to attempt to make an assessment of the nature and quantity of the boulders, although in many cases, it will be impossible to do so with great accuracy. Boulders, can pose major problems for TBMs in terms of slowing down or halting the tunnel advance, cutter damage, and abrasive wear. Although proper selection of the TBM and the cutterhead can reduce the risks, ground uncertainties still cannot be eliminated. The paper reviews a case study of a 3480 mm diameter EPB-TBM in Toronto utilized for completion of 2.5 km tunnel in Glacial Till, crossing the CP railway, HWY 401, a creek, and a confined aquifer. Alignment consists of multiple horizontal curves including small radius curves (r=210 m) at shafts breakthrough. An unexpected boulder cluster lead the contractor to experience extreme damages to the screw conveyor, RFJ system and causing a crack in main motor plate which resulted in losing one of the six main motors. This paper reviews contractor’s solutions and includes discussion on specific claim resolution method used in this project that can be of great value in preparation of specification and GBR for similar projects.

Jun 13, 2021

By R. Fernando

"The Office of Mine Safety and Health Research (NIOSH-OMSHR) currently is leading an effort in the development of the next-generation self-escape apparatus as part of the research imperative directed by the MINER Act of 2006. A multifaceted contract program over the past 3 years delivered key components and base breathing modules to form the basis for developing backpack and vest-style versions of dockable self-contained (closed-circuit) self-escape respirators with hoods (CCMERs). This paper outlines the current status in developing the CCMER that incorporates a docking and switch-over valve (DSOV) for seamless transfer from one breathing device to another, and a hood with an inner mask and speech diaphragm (HMC) for ease of donning, ease of use, and communication ability. Three versions of the CCMER are being pursued, namely: the CCMER-B, which can be worn as a backpack and incorporates the features of a miner’s belt; the CCMER-V, which is worn similar to a miner’s vest and attaches to a miner’s belt; and the CCMER-C, a breathing module cached along the escape route that can be docked to the -B and -V versions. Human factors considerations are a key element in the CCMER design, as it is to be continually worn by the miner while underground, and must be readily accessible for deployment when needed. The CCMERs are designed to be capable of being certified to 42 CFR part 84 standards, including sub-part O for mine use, and to meet MSHA permissibility regulations for use in underground mines. They are sized for sufficient oxygen capacities (Cap 2 and Cap 3 as defined in sub-part O) to yield a duration that is of practical use in a mine escape scenario. INTRODUCTION The National Institute for Occupational Safety and Health (NIOSH) Office of Mine Safety and Health Research (OMSHR) is leading the development of self-escape apparatuses to provide breathing gas to mining personnel operating in the event of an emergency in various capacities underground in environments containing hazardous gas components. The Mine Improvement and New Emergency Response Act of 2006 (also known as the MINER Act) and input from the mining community called for the need to move Self-Contained Self-Rescuer (SCSR) technology to a next-generation status. In response to this need, NIOSH’s Office of Mine Safety and Health Research (OMSHR) established a strategic plan to develop key components and devices with help from external experts knowledgeable in breathing apparatus designs. The US Navy was identified as a key expert in this field through its extensive experience in diving apparatus and life support systems, and development work commenced through Inter-Agency Agreements with OMSHR. A contracts program was also launched with industry experts specializing in this field. This paper outlines the current status in developing the Next-Generation Closed-Circuit Mine Escape Respirators (CCMERs) that could be used for surviving and escaping from a mine following an emergency that renders the mine atmosphere irrespirable."

Jan 1, 2016