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By Michael Schultz, Gregory Sanders

The City of New Haven is proposing to construct Downtown Storm Sewer Infrastructure Improvement project to mitigate on-going stormwater flooding in the Long Wharf District. The proposed project includes a 200 cubic feet per second (cfs) stormwater pump station; and a 914 meter (3,000 linear feet) long tunnel segment with an internal diameter of 2.1 meters (84-inches). The tunnel alignment will cross under the Long Warf railyard and then continue parallel to the Vison Trail Route. This paper presents the local geology and subsurface conditions, as well as discusses the major project challenges and risks including construction in soft marine soils and encountering remnants of the former wharf.

Jun 13, 2021

By T. E. Mccandless

Detrital minerals of mantle origin have been found in the Green River Basin of Southwestern Wyoming (Figure 1). Pyrope, pyrope-almandine, and chrome-bearing clinopyroxene and orthopyroxene occur on the antmounds of Pogonomyrmex Occidentalis. These antmounds are a common sight throughout the western U.S., and were used by early paleontologists as fossil mammal collection sites. The mound is composed of two types of material; (1) soil excavated during the digging of the nest below the surface (maximum depth 3 meters) and (2) larger grains collected from the surface and placed on the mound, probably to prevent erosion. The selection of grains to armor the mound seems to be based largely on the mean diameter of the grain, with other factors such as weight, sphericity, roundness and composition in decreasing order of importance (Wheeler and Wheeler, 1963). The minerals of this study happen to fall within that mean diameter range. The garnets are found on the mounds as 3-6 mm diameter subrounded to subangular grains. The pyroxenes are also 3-6 mm in diameter and are most commonly subangular laths. The minerals themselves show evidence of abrasion, such as frosted surfaces and rounded edges. Orange peel texture is present on some of the grains, which suggests that kelyphitic rims were once present, but have been removed. Also, no similar minerals were found in sieved soil auger samples to depths of 2 to 6 meters taken near the antmounds. These observations imply a distal rather than proximal source for the minerals. Lamproitic rocks of upper mantle origin are found bordering the "Green River Basin. The best known are the Leucite Hills, a series of ultrapotassic volcanics found on the north flank of the Rock Springs Uplift (Carmichael, 1967). Minor occurrences of mica peridotite and ultrapotassic volcanics are also found on the western end of the Uinta Mountains in Utah (Best, et al, 1968). None of these rocks are known to contain minerals like those on the antmounds. The garnets are comprised of purple chrome pyrope, red chrome pyrope-almandine, and pink to orange low chrome pyrope/pyrope-almandine. Oxide statistics for these groups are summarized in Table 1. These three groups are distinct when their Cr203 values are plotted against magnesium number (Figure 2). The chrome pyropes are highest in Cr203 (1.28-2.66%) and have high, restricted Mg number values (0.781-0.826). The chrome pyrope almandines have similarly high Cr203 (1.29-2.62%) but a lower Mg number range. The low chrome pyrope/pyrope-almandines have the lowest Cr203 content (0.09-0.73) and the widest Mg number range (0.534-0.836). Using the classification scheme of Dawson and Stephens (1975) the chrome pyropes are most similar to garnets derived from kimberlite and from garnet lherzolite, websterite, and harzburgite xenoliths in kimberlite. The chrome pyrope-almandines and the low chrome pyrope/ pyrope almandines are similar to garnets derived from eclogite nodules (Figure 3).

Jan 1, 1984

By J. W. Wilson, S. Nakajima, B. D. Singh

According to the Project Independence blueprint, a 270 percent increase in coal production is expected from western coal fields compared to an increase of 100 percent for the nation as a whole. Furthermore, 30 percent of the total United States coal reserves lie in the western states, which are classified as beyond the strippable limits and can be recovered only by underground methods. In view of the fact that the majority of the seams in the West are thicker than those presently mined in other parts of the country, it is important to consider the parameters that relate to mining thick seams and the factors that affect such mining systems. Apart from thick seams, a common feature of many western coal fields is the occurrence of multiple seams that lie in close proximity to one another. These multiple seam deposits present difficult mining problems that have not been encountered to any degree in other U.S. coal fields; for example, ground pressure changes in one mine level caused by mining in the other, sudden water or gas influx from the adjacent levels, the danger of spontaneous combustion in gobs and large and complex subsidence displacements on the surface. Perhaps equally important is the fact that the country can ill afford the present systems of underground mining that attain only 50 to 60 percent coal recovery. With the probability of increased thick seam mining, conservation shall be a focal point in future mine design systems. It is possible that in the future it will be forbidden to adopt the present day wasteful mining methods to ensure that coal can be conserved for future generations.

Jan 1, 1977

By Stephen W. Denton

Planning a mining operation in Alaska will involve the investigation of many parameters common to mine planning anywhere. However, there are some unique circumstances that must be recognized when one considers development of mining operations in Alaska. This paper will not attempt to provide a blueprint for mine planning in Alaska, but hopefully will provide a better understanding of the truly unique nature of the northern latitudes. Given this understanding, the mine planner can better assess the potential hurdles along the road to a successful mining operation. The regulatory trend towards uniform standards for mining throughout the United States exemplifies the necessity for Alaska to prove its unique position in the natural resources picture. The factors which make Alaska truly different from the "Lower 48" can be summarized by four points 1) Remoteness and Size 2) Seasonable Extremes 3) Geologic Immaturity 4) Vegetation and Wildlife

Jan 1, 1984

By Edwin B. Wilson

The purpose of the panel's examination of coal mining research and development is to explore how the various groups that make up this research community might work together more efficiently and be more productive. The community, as defined here, includes federal and state governments, coal producers, manufacturers, unions, universities, and industry sponsored research organizations. The framework chosen for these discussions consists of brief presentations by the panel members on their views of the proper role and function of the group they represent. The panel members were also asked to highlight the economic, technical and institutional constraints that affect the performance of research and development and the use of the results. Following these presentations, a number of prepared questions will be discussed by the panel, and audience participation is invited. These questions were given several weeks ago to the panel members for their study. Before proceeding with the panel member reports, a brief review of the importance of R&D to the coal mining industry would be helpful to setting the stage for a constructive dialogue. It is appropriate to begin this review by mentioning that there is complete agreement among the research community that the major goals are: Improve health and safety Protect the environment Increase capital and labor productivity Increase resource recovery Since the basic functions of the academic, industrial and government sectors are different, we should expect that the research and development objectives and priorities, roles and responsibilities under each major goal will be different for each research group. The differences do not represent problem areas. However, problems will arise if the objectives are not properly interfaced at the appropriate time. The consequences of railing to understand the need for integrated programs will be the classic result, best described by the phrase --"a technical success but a commercial failure."

Jan 1, 1978

By L. Figueroa

Electrochemical methods have potential to treat waters impacted by mining, while simultaneously producing a recoverable metal product to off-set treatment costs. Mining-impacted waters may present challenges with electrochemical treatment due to low concentrations and complex solutions of numerous dissolved metals. This paper presents an evaluation of the potential strengths and limitations of abiotic electrowinning of mining-impacted waters. In particular the impacts of chemical composition on metals removal are evaluated. Results of bench-scale experiments demonstrate the potential to remove metals on the cathode (copper, cadmium, lead), as well as the anode (manganese). Pre-treatment for iron and aluminum may be needed and post-treatment pH adjustment would be necessary. INTRODUCTION Due to continually increasing demand for metals, new technologies and innovative applications of existing technologies are needed to recover metals from mining-impacted waters. Electrochemical methods have long been used for metallurgical processes with solutions containing high concentrations of the target metal. However, electrochemistry also has potential to treat waters with lower metal concentrations, while simultaneously producing a recoverable metal product to offset treatment costs. Electrochemical water treatment may have several benefits over traditional alkaline treatment for acid rock drainage (ARD). Sludge produced from alkaline treatment has high water content that is difficult to dewater, even for treatment plants producing a relatively high-density sludge. For example, the Argo Tunnel Water Treatment Facility (Argo Facility) in Idaho Springs, Colorado uses hydrated lime to produce a high-density sludge with a solids content of 20 to 25 percent and filter cake with solids content from 30 to 35 percent [1]. Furthermore, costs for managing the sludge are significant, approximately $90,000 per year for treating approximately 150 million gallons of water [1]. Although not the case for the Argo Facility, sludge produced from alkaline treatment of ARD has potential to be classified as hazardous. Disposal of sludge also opens up the potential for future liability depending on the sludge’s chemical stability and methods of disposal. In contrast to alkaline treatment, electrochemical treatment produces metals in elemental and other highly-dense forms on the cathode. If metals concentrations and flow rates are sufficiently high, the metals recovered may help offset overall treatment costs. In addition, sludge production would be reduced, if not eliminated altogether, thereby reducing both disposal costs and potential future liabilities as well.

Jan 1, 2019

By Leonard Harris

Mining is a business and, therefore, is expected to make profit for its investors, like any other business. It is a risky business which requires the expertise of professionals from several disciplines to make it successful in the finding, evaluation and development of a new mining venture. Many of the same disciplines, as well as experts in some other fields are required to operate the facilities once they are built. To manage all this, wide-ranging, versatile and sharp managerial skills are required. On the U.S. domestic front, the most important management issues requiring attention today and tomorrow are the increasing unwarranted attacks by anti-mining groups and legislators on the industry and aided by an unchallenged, but widespread, public view that mining is not necessary and damages the environment. Higher costs to mine and process deeper and more refractory ores are also of great concern. More and more attention is being focused, therefore, on overseas projects under the belief that undeveloped countries will recognize the economic value of mineral production and that lower costs can be achieved.

Jan 1, 1993

By Leonard Sugin

The requirements of today's and tomorrow's markets led to a new generation of facilities which handles large tonnages annually, loading them into larger vessels, at higher rates, efficiently and reliably, with minimum labor input, and significantly greater attention to the environment. A great variety of products are handled, including various grades of metallurgical and steaming coal, coke, iron ore in its many forms, shapes and moisture content, phosphates and fertilizer products, bauxite and alumina ores, limestone, sugar and grains, cement and many other products. When we examine the annual tonnages involved in these movements the economic value of handling these products on a bulk basis can be readily seen. Although nearly all these products have been handled by continuous bulk conveyors for many years, recent governmental response to environmental concerns require a re-evaluation of previous procedures. Most air pollution and emission control regulations and ordinances have recognized several specific sources of pollution. Detailed regulations and requirements have been developed concerning smoke emissions, emissions of visible air contaminants and particulate matter from power plants, heating plants, refuse burning equipment, coke ovens, steel furnaces, kilns, and other industrial installations. Although fugitive dust is also an environmental pollutant it is governed by regulations that are more general and therefore, more difficult to apply. A general definition of a "fugitive particle" is any matter which escapes or becomes airborne from an operation or which is emitted into the atmosphere without passing or being conducted through a flue, pipe, stack or other structure designed for the purpose of emitting air pollutants into the atmosphere. This paper deals with the aspects of fugitive dust emissions as they apply to shiploading. Fugitive dust emissions control is important not only because of environmental regulations but also to prevent the loss of valuable product, reduce housekeeping, and reduce breakdown and maintenance problems to land and vessel equipment. The environmental controls for a belt conveyor system are those which will restrict the emission of fugitive dust particles and can be considered as follows:

Jan 1, 1977

By I. K. Choi

In a recent paper by Smith and Wen(1) the adsorption of sodium dodecylsulfate and trimethyldodecylammonium chloride on kaolinite was studied. As would be expected considering the general negative character of kaolinite, except perhaps at quite' acid pH values (2,3,4), it was found that trimethyldodecylammonium chloride adsorbed strongly on kaolinite at basic pH values. Furthermore, it was found that sodium dodecylsulfate adsorbed strongly on kaolinite at acid pH values, particularly at initial 1H values below pH 3 (final pH values near pH 4). It is interesting to note that adsorption of the anionic surfactant was strong under conditions where the kaolinite was apparently slightly negatively charged (2). The present paper reports on an extension of the work by Smith and Wen. In this paper the effects of the presence of dodecyl alcohol and sodium hexametaphosphate on adsorption of sodium dodecylsulfate and trimethyldodecylammonium chloride on kaolinite are considered.

Jan 1, 1967

By Robert Dimock

The successful management of large dispersed mineral operations is dependent upon accurate and timely decision making. The plant locations providing the data to support the decision making process are generally separated by distances which elongate the time required to accumulate the data at a central focus. The need exists to examine operational data in context with total mining operations, and in relation to target projections and historical trends. The use of microcomputers for local information tasks is an established capability. Grouping microcomputers into local-area networks is rapidly becoming established. Interconnecting multiple local-area networks to provide a free flowing stream of information between all operational locations of a mining enterprise is possible with use of some emerging technologies. The benefit of the potential interconnections and rapid transfer of information can readily be seen from a production reporting perspective. Numerous other advantages exist' by providing routing to enable a workgroup to be established between separated work functions.

Jan 1, 1989

By William F. Eichfeld, Robert J. Wenzel

INTRODUCTION The phrase "subsidence control planning" can refer to the use of specific mining methods and-specialized techniques to control subsidence events or it can refer to planning for subsidence by predicting its magnitude and timing and further planning mitigation strategies. In the first case the objective is actually subsidence prevention while in the second it is a design procedure that seeks to maximize the use of both surface and subsurface resources. Neither technology is well developed at this point. The purpose of this presentation is to briefly outline the Department of Energy's Subsidence Program. This program is, in general, bases on the premise that subsidence control technology, by any definition, can be accomplished only through a thorough and rigorous understanding of subsidence phenomena. This understanding must come from many well planned and executed studies of stress redistribution and strata deformation as they occur during mining activities. There is presently considerable incentive to improve our subsidence engineering capabilities due to the desire for increased coal utilization with acceptable environmental impact. Considerable research in this area is being sponsored by federal and state governmental agencies, universities, and the coal industry. Federal sponsorship has been borne by the Department of Energy, the Bureau of Mines, the Office of Surface Mining and the U.S. Geological Survey for the most part. These agencies have carried out basic research in their laboratories and have contracted with other organizations for additional work. At this time most of the available resources are directed toward contract research, especially in DOE. It is the DOE research plan which will be addressed here.

Jan 1, 1982

By Ruiren Jin

In alkaline pulp, galena is depressed by sodium carboxymethyl cellulose (NaCMC), while Cu(II)-activated sphalerite exhibits a high flotability so that satisfied separation can be achieved. In addition to hydrogen bonding, chemical bonding of NaCMC with galena is confirmed by IR; only hydrogen bonding is involved between NaCMC and Cu(II)-activated sphalerite. It is also found that the greater the degree of substitute and polymerization of NaCMC, the stronger the depressive effect of NaCMC and that lower stirring speed favors the depression.

Jan 1, 1987

By P. M. Soupios

An integrated suite of environmental methods was used to characterize the hydrogeological, geological and tectonic regimes of the study area, to determine the geometry of the landfill (depth and spatial extent of electrically conductive anomalies), to define the anisotropy caused by bedrock fabric fractures and to locate potential zones of electrically conductive contamination. The study area which covers an area of about 0.08 Km2 is a municipal solid waste site (MSW), located 20Km West of Herakleion in the central part of Crete (S. Greece). The landfill is located in a northwest oriented valley with highlands to the northeast and southwest. The combination of geophysical methods and chemical analysis are commonly implemented for characterization and management of land-fills. At the particular site, geophysical methods were focused on studying the electrical insolating properties of the materials, electrical con-ducting properties of fluids (leachates) and electromagnetic properties of the disturbed regolith materials in the burial zones. Three different types of geophysical surveys were performed: 1) 2D electrical tomography (ERT), 2) electro-magnetic measurements using very low frequencies (VLF) and 3) electromagnetic conductivity (EM31). Furthermore, in order to calibrate the geophysical methods dielectric spectrometry measurements are conducted. To evaluate the environmental degradation of the area, soil and liquids samples were collected.

Jan 1, 2005

By J. L. Chakravatti

INTRODUCTION Mining of uranium does not differ, in many respects, from the mining of other metals; the ore must be drilled, blasted and transported in an underground or surface mine. Underground mining proceeds by the continuous development and advancement of a network of passages and rooms or stopes from which ore is excavated. As in most mines, rock conditions and ore grades in uranium deposits vary from area to area and between different mines. For mineral benefications of this ore in the mills, use is made of various chemicals, often with toxic or hazardous properties.1 As well as the need to control the more conventional hazards associated with any mining and milling operation, special care needs to be exercised in the mining and milling of uranium because of the radioactive nature of the ore. This requires that we examine closely the radiation hazard areas encountered in the mining and milling of uranium, with the broad overview of some of the basic facts in the radiation hazard control programme. To place the hazard in its proper perspective, we require recognition, evaluation and control of those factors arising in and from the workplace which may cause sickness, impaired health and affect the well being among workers or citizens of the community. The radiation environment in uranium mine is complex and variable. Although uranium ore is only mildly radioactive, it naturally contains a complex mixture of radioactive isotopes. Workers are exposed to external gamma radiation, to some beta radiation and to airborne radon, radon daughters and ore dust. All of these types of exposures warrant considerations in formulating control procedures but, in general, radon daughters are known to present the dominant risk. The basis of dose limitation in radiological protection is risk limitation. Long-term epidemiologic studies of United States uranium miners and that of miners in Czechoslovakia indicate that the incidence of lung cancer can be accounted for by a linear relationship with exposure to radon decay products.2 On the basis of this proportional exposure-risk relationship, a risk coefficient for lung cancer in the range of 1-5.10-4 WLM-1 during the total lifetime, has been estimated by UNSCEAR3 and other researchers. It should be noted that this risk coefficient includes the excess lung cancer risk from external gamma radiation in mines and from other carcinogenic chemical effects, if any, to which the miners are normally exposed during their underground work. It also takes into regard the possible synergistic influences. This paper reviews the occurrence of radiation and its control factors and the development of engineering design features for the environmental control at Denison Mine. NATURAL URANIUM SERIES Uranium is the most common element in the Earth's crust. It is widely distributed in nature in all rocks and is readily measurable in the sea. Hence, radon gas is universally produced in every part of the globe. Mining is patently confined to ores containing more than half a kilogram, or so, per tonne of uranium unless it is combined with other marketable metals. Uranium-238 is the first element in the uranium series. In all, there are 13 radioactive decay products of 238U (Fig. 1), ending up as a stable isotope of Lead-206. The whole basis of the radiological hazards associated with the mining and milling of uranium is dependent on the behaviour of these isotopes during each phase of the process.

Jan 1, 1981

By W. G. Pariseau

Recent advances in rock mass mechanics and computational technology now allow for stability analysis of excavations in "wet" mines where mining-induced changes in rock mass deformation and fluid flow are coupled and time-dependent. All the usual dry mine parameters including the premining stress state and rock mass properties are taken into account, in addition to water pressure and flow in jointed, possibly porous, rock masses. Finite element analyses of shafts and tunnels as circular, elliptical, rectangular and arched-rectangular hole shapes excavated in an initially stressed and pressurized rock mass indicate that the usual guidelines for optimum shape and orientation of single openings apply. Here, optimum means maximizing the minimum wall safety factor, or equivalently, minimizing the peak stress concentration. The results also show that failure originates in elements at the wall and that the minimum safety factor at the wall in the wet case is always less than the dry case regardless of drainage time allowed.

Jan 1, 1995

By W. J. Bronkala

Dense-medium circuits have been installed in many mineral treatment plants since its, original development about thirty years ago. In the intervening, period the process has been thoroughly evaluated and many innovations have been introduced. The Heavy Density. Cyclone is one of the newer systems which has extended the operating range of this process to 65 mesh size. Several different finely divided materials have been used to produce the separating bath but nearly all new plants use a ferro-magnetic medium. The, advantages of magnetic medium include: 1. Smaller recovery plant 2. Lower cost recovery plant both in initial and operating cost 3. Excellent medium stability 4. Dependable medium supply at reasonable and stable cost. Magnetic separators are used to recover this magnetic medium and the smaller plants and lower operating costs are directly related to their use.

Jan 1, 1964

By Volkmar Niemitz

Approximately 30 miles east of Chicago on the southern shores of Lake Michigan stands Bethlehem Steel's newest fully integrated steelmaking facility - the billion dollar Burns Harbor plant. The initial phase of "green field" construction that began in 1963 was directed to the creation of high quality finishing facilities. In late 1964 the 160" plate mill came "on stream" followed closely by Sheet and Tin and Hot Strip facilities. Unit train shipments of slabs primarily from the Lackawanna plant located near Buffalo constituted the input materials for the new mills. In 1967 a hot metal facilities program was announced for Burns Harbor that at its completion would make the plant fully integrated. Incorporated within the program were: 1. A new high performance 50" x 96" slabbing mill complete with a battery of soaking pits. 2. A two vessel Basic Oxygen Furnace Shop. 3. (1) battery of 6 meter high Coke Ovens with attendant coal handling facilities. 4. A 3800 feet long vessel loading & unloading dock. 5. The first conveyor belt fed Blast Furnace in the United States. 6. An extensive materials handling system for receiving, stocking and reclaiming from storage the raw materials for the Blast Furnace and Coke Ovens operation. The intent of this paper is to provide a detailed description of the functions and components of the materials handling system noted above.

Jan 1, 1970

By Emily Wortman-Wunder

As the 2012 president of the Society for Mining, Metallurgy, and Exploration, Inc., I am pleased to present the 2012 issue of the Transactions of the Society for Mining, Metallurgy, and Exploration, Vol. 332. A significant portion of the contribution that we make as a professional society is the publication of professional and technical papers that accelerate the advancement of scientific knowledge and enable the transfer of technology. Communication within the mining community is the key to a successful society. This technology exchange continues a tradition that dates back to the 1871 meeting of 22 mining engineers in Wilkes-Barre, PA, that resulted in the founding of AIME; those individuals envisioned that these transaction volumes “would form a most valuable and greatly needed addition to our professional literature.” This volume fulfills that pledge. The 2012 Transactions is the third Transactions to take advantage of new publication technologies. It is available solely as an online subscription. The new format better suits the way this material is used and, ultimately, better enables the transfer and dissemination of knowledge. The 2012 Transactions contains some of the most interesting research from the past year, including a paper on the uranium boom in Namibia, work on improving the safety of coal pillar extraction, ways to improve the optimization and efficiency of various mine activities and the newest research from the U.S. National Institute for Occupational Safety and Health (NIOSH). The 2012 Transactions consists of a total of 67 technical papers (550 pages, including index), including all 18 papers published in 2012 in the Technical Papers Section of Mining Engineering magazine (Vol. 64) and all 31 papers published in 2012 in Minerals & Metallurgical Processing (Vol. 29). Additionally, this volume contains 18 papers that are being published for the first time in this issue. The papers presented in this volume were written by some of the most distinguished professionals in the industry worldwide. All 67 technical papers were peer-reviewed. The process of review and publication requires much hard work by authors, reviewers and our publications staff. As the 2012 president of SME and on behalf of all our members, I would like to extend our gratitude to all whose volunteer efforts contributed to the publication of this volume.

Jan 1, 2012

By Andrzej Wala, Henry P. Cole, Perry David Passaro

Cognitive representations and misconceptions of flow through circuits is an area which has received little attention from science educators, cognitive psychologists, or accident investigators. Misconceptions are also called Aristotelian thinking. They involve a person using primitive unscientific ways of reasoning to make decisions about events (Piaget, 1929; Nussbaum & Novick, 1982; McCloskey, 1983). The use of such primitive concepts leads to errors in reasoning about scientific and technical problems. The existence of misconceptions is well documented among children, adolescents, and adults involved in learning science concepts (Piaget, 1929; Cole & Raven, 1969; Clement, 1982; Mistrell, 1982; McDermott, 1984; Richardson, 1987). Concepts of flow through circuits are important because miners' conceptual errors about these aspects may be, in part, responsible for two fatal mine disasters. On at least two separate occasions, methane gas explosions occurred in underground mines when separate ventilation systems were connected (Elam, Fuller, Carter, Cavanaugh, Fesak & Painter, 1983; Fesak & Cavanaugh, 1984). A review of these disasters indicates that conceptual errors made by miners may have resulted in the accidents (Cole, Wala, Haley, & Vaught, 1987). In this study, co-author Andrzej Wala, stated that his research had "identified conceptual errors that may have caused the miners in these disasters to make fatal mistakes" (Cole et al. 1987), p. 167. Further exploration of these conceptual errors by Wala has led to the hypothesis that misconceptions of basic aspects of flow distribution changes in mine ventilation circuits, are at least, in part, responsible for some mine disasters caused by errors in ventilation systems (Wala & Cole, 1987). Why should these conceptual errors occur? Ausubel (1963) suggested that students come to a new area of study with their own conceptions or preconceptions about how a process operates. Furthermore, these preconceptions may be in conflict with the empirical data from the discipline. In such cases, learning becomes a process in which new concepts must displace or be re-molded from stable concepts that the student has constructed over many years (Clement, 1982). Given the existing research with misconceptions and the work of Wala and Cole (1987), it was hypothesized that experienced miners; either working miners, students of mining engineering, or professional mining engineers, harbored misconceptions about the formal or conceptual aspects of mine ventilation circuits. The misconceptions hypothesized to exist involved flow distribution changes in complex mine ventilation circuits; specifically, how does flow distribution change when a ventilation circuit pathway is altered? Given this information, the following research questions were proposed. Research Questions 1. Do experienced miners and mining engineers harbor misconceptions about mine ventilation systems? This question was addressed by: A. The administration of the Cutthrough Ventilation Arrangements (CVA) exercise that measures subjects' performance level when making decisions about major ventilation changes when connecting two mine sections;

Jan 1, 1989

By RICKARD HANSEN

Vehicle fires in underground mines pose a certain risk for which measures to prevent or mitigate the fires are highly important. Fire protection measures can be divided into active and passive measures, where active measures require an external power to work in the event of a fire, and passive measures could include an existing partition preventing fire spread. As passive fire protection does not rely on activation, it is expected to provide high reliability and a robust solution, and should be considered during the design process. This paper investigates passive fire protection measures that could be implemented in the design of mining vehicles. It was found that passive fire protection should include the use of several measures simultaneously to ensure fire protection throughout the different phases of a fire. Threshold distances for fuel components were calculated, and it was found that combining hydraulic hoses and electrical cables resulted in larger threshold distances. A pool fire along the underside of a vehicle will pose a certain risk, and passive measures should be focused on ignition prevention, making high demands on the insulation/shielding along the underside. Any occurring tire fire may pose a challenge, and the priority should be on preventing ignition. Potential measures include shielding the wheelhouse and applying fire-resistant sealings.