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By R. Heiser, J. Vendetti, B. P. Connor, E. J. Haas

Health and safety indicators help mine sites predict the likelihood of an event, advance initiatives to control risks, and track progress. Although useful to encourage individuals within the mining companies to work together to identify such indicators, executing risk assessments comes with challenges. Specifically, varying or inaccurate perceptions of risk, in addition to trust and buy-in of a risk management system, contribute to inconsistent levels of participation in risk programs. This paper focuses on one trona mine’s experience in the development and implementation of a field-level risk assessment program to help its organization understand and manage risk to an acceptable level. Through a transformational process of ongoing leadership development, support and communication, Solvay Green River fostered a culture grounded in risk assessment, safety interactions and hazard correction. The application of consistent risk assessment tools was critical to create a participatory workforce that not only talks about safety but actively identifies factors that contribute to hazards and potential incidents. In this paper, reflecting on the mine’s previous process of risk-assessment implementation provides examples of likely barriers that sites may encounter when trying to document and manage risks, as well as a variety of mini case examples that showcase how the organization worked through these barriers to facilitate the identification of leading indicators to ultimately reduce incidents.

Jan 1, 2017

By F. Calizaya

This study summarizes the results of various numerical and laboratory experiments per-formed to study the effect of airflow recirculation on gas concentration. The numerical exercises were carried out on a simulated mine ventilation net-work. The laboratory experiments were conducted at the Mackay School of Mines' airflow monitoring system in Reno, Nevada. In both cases, the airflow was recirculated through the system by means of a main fan and a set of booster fans. The booster fans were positioned to produce two types of recirculation: In line and Cross-cut. For each type, various recirculation conditions were generated by changing the booster fan pressure. During each test, the gas emission rate at the simulated working face was kept constant. The study illustrates the conditions under which controlled airflow recirculation may be used to solve a district ventilation problem.

Jan 1, 1991

By Spencer R. Titley

The subject of this lecture, a late century perspective on porphyry copper geology, is one of current interest and importance as the search for these ores remains intense. It is presented in the belief that an appreciation of our present understanding of the subject requires it to be viewed historically, thus providing a basis for evaluating appropriate directions for con¬tinued study. At the outset, it is important to note that the technology of mining and extractive metallurgy has developed ore from these low grade orebodies, starting with D. C. Jackling, and has continued to create them as copper grade and price have diminished. But the continued search for them is a geological problem that responds to growing expectations of people and societies; exploration based upon ever increasing knowledge of the habits of the ores has been very successful. This is the story of evolution of geological thought and practice in porphyry ore search across an interval of time beginning with the bulk mining of "low grade copper ores at Bingham and ending with late Century concepts. "How did we get here?" The lecture concerns the ideas of many different people. The ideas and events discussed reflect a bias on North American thought, where the great low grade orebodies were first recognized as such and where many of the basic geological ideas were developed. A very great number of geologists have contributed to this understanding. In no sense is it meant to minimize the contributions to the story that have evolved in the study and mining of ores of the Andes, whose development and expansion has been nearly synchronous with that in North America - nor to minimized comparable contributions made in the late century from studies of the newer discoveries of deposits in other regions, especially the southwestern Pacific regions. In expansion of this topic, I have found that many important concepts are marked by appropriate publication but some are not, or I have not been able to discover documentation. Many notions appear to have become conventional knowledge without publication, mostly being geological viewpoints developed synchronously from similar observation. Thus, apologies are extended in advance to those whose work I have might have missed and to those unknown to me whose unpublished ideas may have seeped into the pool of common knowledge without appropriate recognition. . The analysis here addresses events of two time segments, an older one extending from the developments at Bingham in the early 1900s through the Second World War, ending about 1950; the second period extends from that time to the present. This separation is seen in Figure 1, which traces numbers of publications through the period as extracted from some 700 publications, again with a North American bias, from an annotated bibliography of porphyry copper geology in preparation. During the early period, exploration was "immature" in North America, that is, geologists looked for new districts and sites of the deposits. Outcrops were sought that carried the signatures of former mineralization and regional controls related to structural geology were closely studied. In the later period, North American exploration had "matured" into a study of districts, rather than a search for them. As the studies of these ores intensified during the younger period concommitant with increasing demands for the metal, they did so with a broadened understanding of some habits of occurrence, of hydrothermal alteration, mineral zoning, petrology, and geochemical and geophysical signatures. Outside of North America, search remained "immature" but closely related to the

Jan 1, 1997

By E. H. Christiansen

The most valuable gem- quality red beryl comes from the Wah Wah Mountains of south-western Utah (Fig. 1). Red beryl occurs as a secondary mineral in topaz rhyolite. Marketable crystals from the Wah Wah Mountains have been produced from the Violet Mine, operated on a limited scale since 1976 under the ownership of the Harris family of Delta, UT. From 1989 to 1995, production from the mine amounted to more than $3 million with an inventory of several million dollars of unsold gems (Harris, 1995). In 1994, Kennecott Exploration leased the mine and surrounding claims to determine reserves and feasibility of gem recovery. Mining and exploration activity are continuing. Previous work on red beryl has dealt mainly with crystallographic, chemical and optical properties of the crystals (Shigley and Foord, 1984) with only general descriptions of the geology (Ream, 1979). However, the conditions needed for formation of red beryl have not been well constrained. It is generally proposed that beryl originates by precipitation in fractures and vugs from high-temperature gases as they are released from slowly cooled rhyolite lava. Dozens of topaz rhyolite flows and domes, similar in composition to the beryl-bearing flow in the Wah Wah Mountains, occur across the western United States (Christiansen et al., 1986). All of these flows devitrified to form vapor-phase topaz and locally other vapor-phase minerals such as bixbyite, garnet, hematite, pseudo-broo- kite and fluorite. But the occurrence of beryl is rare. Even within the rhyolite flow that hosts the red beryl, the productive open pits comprise only a small fraction of the surface area of the flow. Apparently, the conditions that favor the formation of red beryl are rarely achieved. Geologic setting The rhyolite flow that hosts the red beryl deposit lies along the eastern flank of the Wah Wah Mountains (Fig. 1). Prevolcanic rocks consist of Proterozoic, Paleozoic and Mesozoic sedimentary rocks that were folded and thrust to the east during the Sevier orogeny. Cenozoic volcanism began about 34 Ma. It consisted mostly of large volume dacitic ash flows and lesser volumes of low- silica rhyolite and andesitic lava flows. Beginning about 23 Ma, the style and composition of volcanism changed to smaller-volume, ash-flow and dome-forming eruptions of high-silica rhyolite and trachyandesitic lava. These rocks form the Blawn Formation of which the beryl-bearing rhyolite is one member (Best et al., 1987). Abbott et al. (1983) reported a K-Ar age of 22.1 + 0.8 Ma for this flow. It is probably the oldest topaz rhyolite flow in the Wah Wah Mountains. A subsequent episode (12 to 13 Ma) of bimodal magmatism produced the Steamboat Mountain Formation. The rhyolitic part of that is locally topaz-bearing. Displacement on the late Cenozoic extensional faults that formed the north-trending mountain ranges began about 22 Ma. Geology of the Violet Mine The rhyolite that hosts the red beryl deposit is part of a flowldome complex that overlies nonwelded tuff of cogenetic origin. This rhyolite is exposed over an area of about 9 km2 (3.5 sq miles) (Fig. 1). An unknown additional portion of the rhyolite is concealed beneath younger mafic lavas and sediments.

Jan 1, 1997

By S. Schina

Part of the Imittos Western Peripheral Motorway in Athens is the twin road tunnel in the vicinity of American College, with 20m excavation diameter. In the paper, the environmental and other requirements, the geometry and the geological – geotechnical characteristics of the rock formations in the construction area are given. Information regarding the modeling and analysis methods that are used for the design of the temporary support, the final lining and the wedge and slope stability analysis is described thoroughly. Finally, the results of the analyses are compared with these of measurements and general remarks during the construction of the tunnels.

Jan 1, 2001

By C. Roos

Tradicionalmente en la industria minera, el flujo principal del proceso funcional para la evaluación de recursos y reservas procede de geólogos que elaboran el modelo geológico, de allí a los geólogos que hacen la estimación de los recursos (los modeladores) quienes estiman los grados, y a los ingenieros de mina que desarrollan el diseño de la mina y su calendario. La interfaz entre estas tres disciplinas no está siempre exenta de baches. Las presunciones hechas durante una etapa del proceso no siempre son comunicadas a los demás, a pesar que la mayoría de las empresas mineras tienen procedimientos y protocolos establecidos para promover la comunicación a lo largo de las distintas disciplinas. Estos procedimientos no siempre logran su propósito debido a una variedad de razones que incluyen restricciones de tiempo, no tener disponible a las personas apropiadas, o a una falta de entendimiento de lo que las otras disciplinas requieren, y el proceso de traspaso puede degenerar en el envío de archivos a la siguiente disciplina en el flujo de proceso. Este artículo se ocupa de la interfaz entre la estimación del recurso y las disciplinas de la ingeniería de minas y el esquema de algunas de las presunciones comunes hechas al generar un modelo del recurso y los riesgos que los ingenieros podrían correr al elevar los grados de corte, optimizar calendarios o realizar predicciones. Los casos de estudio presentados se centran en depósitos de oro a cielo abierto, pero los conceptos deben ser aplicables a toda la industria. Aquí también proveemos un resumen de preguntas clave y recomendaciones.

Jan 1, 2014

By Vinícius Resende Domingues, André Pacheco de Assis, Bernardo Cascão Pires e Albuquerque

"The increasing demand for underground works in urban centers, and in particular the need to build undercrossing tunnels, requires constant evolution in building techniques in order to achieve success and safety. In the case of Brasilia, capital of Brazil, in order to preserve an important avenue (Eixo Monumental), where are located many historical monuments, the construction of a tunnel was envisioned as an option to interconnect the National Stadium (on one side of the avenue) to the Convention Center Ulysses Guimarães (on the other side). The excavation design is comprised of a coverage smaller than one diameter, height of 7.5 m, width of 9.0 m and length of 25 m. In order to enable a negligible influence on the avenue’s usage, the structure is designed as a portico system composed of pipe canopy. In this context, this study presents the portico analytical solution computed with the aid of the software Mathematica and a numerical solution using the software ABAQUS. INTRODUCTION Undercrossing tunnels are increasingly common in urban centers as alternative roads or as access to underground works of large dimensions (stations and parking lots). The geomechanical conditions of the soil mass, not always favorable, and the low distance between tunnel’s ceiling and the surface require intense treatment of the soil massif and execution of a rigid support system. The importance of the road just above the undercrossing tunnel emphasizes the need for a highly competent monitoring system because existing structures require minimum allowable displacement and do not allow the interruption of traffic. The soils that are excavated for the construction of undercrossing tunnels are composed, in most cases, of layers of fill and / or soft soil or weak rock, showing stability problems when subjected to tunneling operations. The combination of low coverage and week ground is solved by soil improvement techniques and strengthening of the excavated cross-section with further advance with the so-called New Austrian Tunneling Method (NATM). Another option is to build structural frames that support the surface. In this research, and based on the context of a case study, we propose the study of the construction technique comprising a portico structure composed of pipe canopy. For this paper, the technical standards used are the Brazilian ones as the case study refers to this country."

Jan 1, 2016

By F. Habashi

The peninsula that lies between the Black and Mediterranean seas, called Asia Minor by the Romans and Anatolia by the Greeks, was one of the crossroads of ancient civilizations. The fall of Constantinople in 1453 was a turning point in the history of mankind. Visits to Istanbul, Ankara, Eskisehir, Cappadocia, and Trabzon will be given together with the history of the country. Mineral resources of the country will also be briefly outlined.

Feb 23, 2014

By S. B. Bealko

In response to recent mining disasters and new mine rescue team legislation, NIOSH researchers conducted meetings across the United States with mine emergency response experts to investigate current needs and issues. Some of the issues include emergency response preparedness, mine rescue contests, real-life training capabilities, and training facilities. Many new teams are being formed that must be trained for mine rescue team competitions as well as be ready to respond to a variety of mine emergencies including a fire or explosion, a massive roof collapse, mine inundations, or vertical shaft rescue situations. Therefore, it is important that these teams are adequately prepared and trained. This paper presents a summary of domestic and international coal mine rescue training facilities and identifies those that provide unique, real-life, and/or state-of-the-art training. Research findings from this report will be used in further NIOSH investigations to improve coal mine rescue training. DISCLAIMER: The findings and conclusions in this report are those of the author(s) and do not necessarily represent the views of the National Institute for Occupational Safety and Health.

Jan 1, 2009

By D. A. Harman

The U.S. Environmental Protection Agency recently recognized Newmont and other mining companies, along with the Nevada Division of Environmental Protection for their voluntary work in reducing mercury air emissions. One example of this voluntary effort is the installation of a reactive scrubber to capture mercury vapor from the exhaust of a carbon regeneration kiln at Newmont’s Twin Creeks Mine. After considering the available technologies, a proprietary reactive scrubber, developed by ADA Technologies, Inc., was selected and is currently being commissioned. Mercury removal rates greater than 90% have been documented.

Jan 1, 2004

By R. V. Ramani

In 1970, of the 603 million tons of coal produced in the United States, 339 million tons, or 56%, were produced by under- ground mines. While the ratio of underground to surface production has been decreasing in the last few years, it is anticipated that a 60:40 ratio of underground to surface-mined coal will remain for some time. Underground coal operators are continuing to invest in new mines and are interested in increasing the efficiency of all their operations. One area for improvement is in mine planning and design, particularly in the area of selection of equipment for operation. Because of the availability of a wide variety of equipment, a fair degree of selectivity can be exercised in the choice of equipment for a particular job. However, such a choice must be made on the basis of technological facts and forecasts related to the mining operation. If the mining conditions can be reasonably predicted, along with a mining plan, it should be possible to insure the selection of the right equipment for the particular application. In order to increase the efficiency of underground coal operations, it is necessary to understand not only the operating system in detail, but the inter-relationships between system components and the operating environment. With such an understanding comes the application of simulation and other operations research techniques to plan and operate mining systems. Computer simulation studies have been successfully adapted to underground coal mining, and applications by Prelaz et al. (1965), and Manula and Sanford (1969) are some that are being used by the mining companies. However, a need still exists for better understanding of certain intra-system and system-environment interactions in order that computer simulation programs may be provided with better input data for more effective application. This paper deals with one aspect of the coal-winning system in need of better definition, namely, studying the performance of continuous miners.

Jan 1, 1973

By F. Khorram

Image processing is a technique that simulates the human vision system. This technique enables applying every statistical or intelligent operation to recognize differences. In this way this new technique is used in quality control systems in most industries. Studying sedimentary rocks is very important from the economic point of view. Some units of sedimentary sequences involve different mineral deposits, hydrocarbon and water resources. Therefore it is important to identify and classify different sedimentary rocks. Descriptive classification of sedimentary rocks is usually based on visual and textural features and chemical composition of a sample. In this paper different samples of a limestone mine in central part of Iran are classified. The samples were collected from different parts of the mine and crushed down in size from 2.58 cm to 3.58 cm. The rock samples were labeled based on percentage of chemical and lithological compositions. Each sample was assigned to one of the distinguished groups. The images of the samples were taken in appropriate environment and processed. A total of 74 features were extracted from the identified rock samples in all images. In order to feature dimensional decrease, principal component analysis method was used. Then Bayesian statistical algorithm was used as a useful tool for classification. Classification Correctness Rate (CCR), calculated for the test data sets are %88, %68, %61 and %72 for the first to fourth class respectively. Therefore it can be inferred that the extracted features of images are appropriate indicators for different samples identification. These precise results besides the advantages of image processing technique, which are increasing speed of operation and decreasing cost, appears to be a desirable success.

Jan 1, 2012

By Leon Maday, Robert Robinson, Judy Cochran, Don Davis

Over the past 20 years, several soft-ground tunnels have been successfully completed in the Seattle area. These tunnels were built using design-bid-build contracting methods, and have benefited from advancing technologies in exploration, design and construction methods. Owners have utilized various contractual means to share some of the risks that are inherent to tunneling projects. This has helped to foster a competitive bidding environment and to resolve issues related to unanticipated underground conditions in a fair manner. This paper presents case histories of tunnels constructed by King County and the Washington Dept. of Transportation that illustrate a common approach to design and construction issues. The common thread is successful project completion with minor cost changes under the design-bid-build contracting method. Lessons learned from these projects are being applied to the upcoming King County Brightwater Project tunnels, Sound Transit’s Light “Link” Rail tunnels and other tunnel projects.

Jan 1, 2005

By G. Bourque

Early in the design stage of their new concentrator for the Mount Wright Plant, Quebec Cartier Mining decided to use a process computer for total control of crushing, grinding and concentrating. A map of the area is given in figure 1 and a view of the plant in figure 2. Although the use of process computers is not a new idea in petrochemical and chemical industries, their use in the mining industry is very limited. We innovated in using the computer, not only for data logging, as we have seen in some other plants, but a sole operator located in the administration building, starts and stops mill lines, crushers, load-out system, tailings, thickeners, etc ... by means of a CRT console. Our process is fairly simple as can be seen on the schematic process flow diagram (figure 3). .The ore, carried by 136t diesel electric trucks, is dumped through ore pockets onto two primary pan feeders. The feeders supply two 1,52mx2,79m gyratory crushers which reduce the ore to minus 20,32 cm. Each crushing line have a capacity of 5600t per hour and feed a shuttle conveyor distributing the crude ore into six silos.

Jan 1, 1979

By M. SIDDARAJU, Rameshwar Sah, Satendra Kumar, Arvind Jaiswal

The study explores a novel process to sinter porous iron ore with improved productivity and quality. The iron ore is pre-processed with calcined lime to temporarily close pores, preventing water absorption during granulation. This enhances reaction kinetics and early slag formation during sintering, resulting in significant improvements in sinter productivity, product yield, and cold strength property.

Feb 28, 2022

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 J. L. Roll

The Surface Mining Control and Reclamation Act of 1977 (SMCRA) and the regulations promulgated for that "Act" have resulted in changes to surface mining operations in order to comply with the stringent federally enforced reclamation requirements for prime farmland. In many instances the operator has modified surface mining operations to meet the prime farmland requirements through changes to mining equipment operation, addition of new equipment targeted for reclamation or the use of totally different mining techniques. The major challenge to mine operators has been how to use existing mining equipment to meet the requirements of the "Act." Freeman United Coal Mining Company opened the first new large surface coal mine in Illinois following passage of the "Act." The Industry Mine, located near Macomb, Illinois started mining operations during March of 1982 and was required therefore, to meet all of the requirements of the "Act" including prime farmland restoration. At the Industry Mine a shovel and a cross-pit bucket wheel excavator (wheel) are used for overburden removal and the wheel is addition- ally utilized to assist in reclamation operations. The wheel mines the subsoil thereby elliminating scraper placement of that subsoil and the attendant compaction problems with scraper placed subsoil. The wheel is used to convey topsoil stock- piles from the highwall to the mined overburden in order to lessen scraper traffic and possible compaction on the graded overburden during top- soil removal and replacement. Close control of the operation of the wheel yields more uniform wheel spoil ridges which then require less grading prior to topsoil replacement.

Jan 1, 1986

By E. F. Schnitzer

During 1996 and 1997, Oregon experienced flooding on a scale not seen in many years. Some gravel pits located near rivers experienced erosion. In several cases, breaches occurred between the gravel pit and the river. Initial evaluation of several sites that experienced these breaches showed that impacts to the river system were complex and varied significantly from site to site. The impacts to the adjacent river system may be viewed as positive and negative. Several flood-plain-mining sites in Oregon located in areas of historic river flow reverted to active riverbeds. In many cases, state and federal fisheries biologists and university researchers saw the resulting increase in channel complexity and habitat as favorable. The Oregon Department of Geology and Mineral Industries —Mined Land Reclamation Program (DOGAMI-MLR) is studying the effects to the off-channel areas that resulted from the 1996 floods. More data is needed to make sound flood-plain decisions regarding mining.

Jan 1, 1999

By Howard M. Cotton

Early in 1977, Amoco Production Company and Houston Chemicals, a subsidiary of Pittsburg Plate Glass (PPG) Industries, started producing iodine commercially in northwestern Oklahoma. This is significant because it is the first plant in over 40 years to be built in the United States with iodine as its sole commercial product. With the exception of a limited amount of iodine produced by Dow Chemical in Michigan, the United States is dependent upon imports from Chile and Japan for its iodine needs. The two million pounds of iodine produced annually from the Woodward plant will supply over one-third of the United States' requirements. Routine analysis of subsurface brines by the Formation Water Lab at the Amoco Production Company Research Center in Tulsa, Oklahoma, revealed unusually high concentrations of certain potentially economic minerals. Investigations determined that, of the minerals in question, iodine appeared to offer the best potential. The brines in question are located in the Morrow sands (basal Pennsylvanian) at a depth of 7,175 to 7.400 feet, in an area where Amoco has been active in a gas play for the past 20 years. The regional iodine concentration ranges from 10 to 700 ppm and averages around 300 ppm with the project area. The project is located 8 miles north and slightly east of the town of Woodward, where the well-developed, porous, and permeable sands of the Woodward trench contain large volumes of brine.

Jan 1, 1978

By S. Agarwal

The mining industry collects a significant amount of operational data. However, gleaning useful information from the terabytes of data is difficult, and not just because of the sheer volume of the data. Therefore, an automated tool was developed at the University of Alaska Fairbanks to go through data and apply very sophisticated statistical and neural network techniques, to identify the data streams that are important to a process. This paper presents results from the tool as applied to SAG mill data from a gold mine. The results were benched against commercial tool. Results indicate that there was little or no loss in performance by automating the very complicated process of neural network modeling. Therefore, the intent of the exercise, to examine if complicated modeling tasks can be automated, was realized.

Jan 1, 2011