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By E. J. Berentsen

The Turquoise Ridge gold deposit is located near the Getchell Mine, 72 km (42 miles)northeast of Winnemucca, NV (Fig. 1). The deposit is owned by Getchell Gold Corp. The host rocks consist of Ordovician and Cambrian age shales and limestones. They have been crosscut by the northeast-trending Turquoise Ridge shear zone and northwest-trending shear zones. Gold mineralization occurs at depths from 427 to 671 m (1,400to 2,200 ft) along the intersection of these structures. Large tonnage, flat-lying deposits occur where folded, favorable beds are intersected by the faults. The carbonate in the beds has been replaced with silica, pyrite and arsenic sulfides.

Jan 1, 1996

By Wern-ping N. Chen

Pressure tunnel includes water-supply tunnels and tunnels for hydroelectrical power plants. Their design principles are different from those of water/wastewater/conveyance and transportation tunnels. Though theoretical pressure tunnel design guidelines exist, a comprehensive guide to summarize these guidelines to facilitate the planning and design of a pressure tunnel program is lacking. The purpose of this paper is to fulfill this need. It first provides key pressure tunnel design concepts in hard rock environment; then, it illustrates associated final lining design principles, including the design of un-reinforced concrete lining, steel lining, and reinforced concrete lining. Design diagrams and a flowchart for the reinforced concrete lining design are provided.

Dec 1, 2022

By N. C. Trivedi

Natural calcium carbonate, commonly known as limestone is an abundant resource pretty much worldwide. Calcium carbonate occurs naturally as the main constituent of chalk, limestone, and marble. One of the unique characteristics of this abundant mineral is its versatility. Major markets for calcium carbonate are: paper, plastics, caulks and sealants, carpet backing, paint, and food additives. This broad spectrum of consuming industries has warranted producers of this industrial mineral to be innovative and quality focused simply to meet the ever increasing demands for performance. This need for improving performance of calcium carbonate has led to the development of new sources of calcium carbonate, natural as well as synthetic.

Jan 1, 2002

By K. C. Kocsis

"Diesel-powered equipment has allowed the mining industry to raise production rates and significantly improve productivity, as it is rugged, mobile and reliable, but its widespread use in underground mines has generated concerns regarding the exposure of mine workers to harmful diesel engine exhaust gases and particulate components such as diesel particulate matter (DPM), which has recently been classified as a human carcinogen by the International Agency for Research on Cancer. The agency expressed further concerns that workers’ exposure to high DPM concentrations can increase the risk of cardiovascular, cardiopulmonary and respiratory illnesses. Three emerging technologies could have the ability to replace dieselpowered equipment and remove DPM from underground mines: fuel-cell-powered mining equipment, battery-powered mining equipment and advanced material handling systems. This paper reviews them and assesses whether they have reached the point where the pollutants emitted by diesel-powered equipment can be removed from underground mines through the introduction of zero-emission mining equipment and power systems. Information is also provided from the results of a feasibility study, including a detailed cost benefit analysis, carried out at six Canadian and nine U.S. underground mines, which looked at the possibility of replacing diesel-powered production equipment with fuel-cell-powered equipment. The remarkable pace at which battery technology is progressing is also reviewed, and the feasibility of replacing diesel-powered mining equipment with battery-powered equipment is assessed. IntroductionHazardous pollutants in underground mines. Why is it important to remove diesel particulate matter (DPM) from underground mines? Over the past 40 years, diesel-powered equipment has allowed the mining industry to achieve rising production rates and major improvements in productivity, as the diesel engine is an economical source of power and diesel-powered equipment is usually rugged, mobile and reliable. On the negative side, the toxicity of some diesel exhaust gases is well known (Grenier et al., 2001), and the widespread use of diesel-powered equipment in underground mines has generated increasing concerns about the occupational exposure of mine workers to harmful diesel engine exhaust gases and particulate components such as DPM. Diesel equipment also entails other hazards like heat and humidity. Exposure to excessive heat can cause heat illnesses, such as heat rash, heat exhaustion and heat stroke (Donoghue, 2004; Roghanchi et al., 2016), and a hot and humid underground environment negatively affects the efficiency of the workforce, which may result in a decline in production output (Roghanchi et al., 2017)."

Jan 10, 2017

By M. M. Rajkovich

Just prior to the close of the century, the Federal Mine Safety and Health Review Commission issued its long-awaited decision in Berwind Natural Resources, et al v. Secretary of Labor, to usher in the new millennium. The case arose as a result of a mine explosion in Eastern Kentucky resulting in MSHA’s issuance of 225 citations, not only to the contractor, but to four affiliated entities of Berwind Corporation. While an Administrative Law Judge dismissed those citations as to three of the Berwind entities, both MSHA and the remaining Berwind entity appealed the case to the Commission. Although the Commission effectively left intact the Administrative Law Judge’s decision, it announced a new theory of liability that would apparently be applied in the future, namely the Unitary Operator Theory. This presentation will provide an in-depth look into the Berwind decision and explore the means under which MSHA might impose liability for contractor violations upon other entities in the future.

Jan 1, 2001

Coal that meets customer specifications is often stored in silos before being loaded into cars. It is often found that coal in a particular car does not meet customer specifications due to the mixing of coal inside the silo. Some new contracts require meeting specifications on a per car basis. Silo flow models are used to predict quality in such cases. However, coming up with an accurate silo flow model for each case is very difficult and time consuming. This paper examines the viability of using an online analyzer at the loading end of the silo in conjunction with a feedback circuit, to optimize the quality of the coal being loaded into trains, so that each car meets quality specifications.

Jan 1, 2000

By Ian McFeat-Smith

Despite a present, short-term economic recession, a remarkable enthusiasm exists in Hong Kong for building infrastructure including major tunnel projects. This paper provides details of current and recent bored tunnel works together with an insight into the impressive list of future underground projects planned by the MTRC,KCRC, Highways Department and Drainage Services Department for the next decade. Risks for each of these works including pipejacking, mixed face and rock tunnelling generally in Hong Kong are also identified. From this is evident that the scale and difficulty of such works continues to increase, requiring the use of more sophisticated methods of construction, the need for better methods of assessing and managing risks and for Government to utilize improved, more equitable Conditions of Contract for such major tunnelling projects.

Jan 1, 2001

By M. Lohk, Y. -. R. Pastarus

Oil shale industry of Estonia provides a significant contribution to the country’s economy, but causes a large number of different problems. In spite of high economical parameters of the current underground mining (room-and-pillar) technology it is not effective. Backfill technology will be applicable in condition of Estonian oil shale mines. Nowadays attention has been focused on the use of combustion and mining by-products as filling materials. Use of ash and limestone in mining industry is treated as a part of mining technology, not as a waste disposal. Underground utilization of wastes reduces the volume and area required for surface disposal, environmental taxes. It improves the quality of mining works. The use of backfill technology has great impact on mining practice in Estonian oil shale industry.

Jan 1, 2011

By H. D. Lelono, M. Walden, G. Johnson

3D modelling can be used throughout the mine lifecycle and has proven to be a powerful tool for consultants and mining companies. One of the most significant benefits of 3D models is their ability to enhance collaboration, communication, and understanding between the mine owner, design engineers, and other relevant stakeholders that have a shared interest in responsible mining and site management. Tailings and mine waste management is an interdisciplinary effort that requires effective coordination and communication between a wide range of consultants, operators, and stakeholders alike. The increased emphasis on Environmental, Social, and Corporate Governance (ESG) highlights the importance for mine operators to engage and communicate with all parties involved in the planning, permitting, operation, and closure of mine sites. 3D models are valuable tools that can be used for development of geotechnical conceptual models, allowing for improved design and monitoring of Tailings Storage Facilities (TSFs). A clear conceptual understanding of a TSFs subsurface geology and foundation characterization is essential for proper tailings management, design, and planning. Visualization with 3D modelling can simplify the interpretation of the, oftentimes intricate, mine sight subsurface settings and allows for quick and effective geotechnical conceptualization. 3D models can be used to identify data gaps, optimize field investigations, and streamline the development of numerical stability or groundwater models. They can help communicate the complex nature of subsurface and TSF interactions in a clear, concise, and accurate manner to both technical and nontechnical stakeholders. This paper discusses some of the benefits of 3D modelling in relation to geotechnical analysis for tailings management and provides methodologies for how to improve upon some methodologies that are considered industry standards.

Feb 1, 2023

By Arthur Miller

Most of the production of copper in the United States comes from a few large companies. Often overlooked, however, are the more numerous small mining operations, which collectively produce a significant portion of the nation's copper. The objective of this paper is to describe the operations of a small mining company - Ranchers Exploration and Development Corporation - how it views its place in this industry of giants, how it exploits the advantages offered by its relatively small size, and how it protects itself from the hazards being small introduces. Environment is, of course, a critical factor for such a company because it does not have the resources which help large companies weather periods of financial stress. Ideally, this environment is characterized by a heal thy economy, strong product demand, relatively stable prices , adequate grades and tonnages of ore commensurate with depth and over-burden, ready access to utilities, a dependable labor pool, and suitable technical "know how". When the environment is right, properties which were previously uneconomical to operate attract the attention of companies whose primary interest is a return on investment commensurate with risk over a reasonable period of time. Naturally, the amount of the investment and the duration of operation determines the size of the company which would be interested in such a venture. Such is the case with Ranchers Bluebird Mine at Miami, Arizona - a small property operated by a small company in a favorable economic environment.

Jan 1, 1967

Ion exchange (IX) has been in use for a long time, references to IX are made in The Bible, Exodus Chapter 15 vs. 22-25 ?and the waters were made sweet?.1, 2 Aristotle noted a reduction in the salt content of water when passed through certain types of sand, a phenomena probably associated with ion exchange characteristics of zeolites. Some major milestones in IX development include; ? ~ 1400 BC Moses ? ~ 330 BC Aristotle ? 1850 the discovery of the IX process3 ? 1909 Gans proposed zeolites for gold recovery ? 1935 sulfonated coals used for water softening ? 1939 copper recovery from Rayon Production ? 1940 The Rare Earth Project at Ames ? 1952 first South African U IX mine at West Rand (first SX of U using amines 1957) ? 1954 first U IX in USA at Shiprock Mine N.M. USA. ? Late 1950?s U IX over 50 fixed bed systems installed in North America ? 1950?s-1960?s FSU introduce U IX both fixed bed and RIP ? 1968 Gold IX (RIP) Muruntau Uzbekistan (CIL wasn?t commercialized until 1973) ? Mid 1970?s FSU & USA independently develop ISL combined with IX for U recovery ? 1978 Chinese Tungsten IX commercial Plant ? 1984 Uranium extraction from seawater ? 2004 Recovery of Gallium using hydroxyamic acid ligands ? Current ? Commercialization of IX for recovery of gold thiosulfate. Ion exchangers can be naturally occurring or synthetic; the majority of ion exchange materials in use today are synthetic resins based upon organic polymers such as polystyrene or methacrylate. Into more modern times the use of ion exchange for metal recovery was first proposed for the recovery of gold using zeolites in 1909.4 In 1939 copper was being recovered from the manufacturing of Rayon using ion exchange5 a development that continued applicability through to current times in the production/recovery of copper and nickel in ammoniacal leach processes. In early 1949 researchers at the Rohm & Haas Company discovered that hexavalent uranium existed as an ionic complex in sulfuric acid leach liquors, and that quaternary ammonium anion exchange resins exhibited a high selectivity for this ionic species6 The first commercial application of this technology went on-stream in October 1952 at the West Rand Consolidated Mines, Ltd operation in South Africa. 7 Ion Exchange has been applied for the recovery and purification of a range of metals;8 ? Uranium, Thorium and transuranic elements ? Rare Earths ? Gold, Silver and platinum group metals (PGM?s) ? Chromium, Copper, Zinc, Nickel, Cobalt ? Refractory Metals; Molybdate, Vanadate, Tungstate, Rhenium Mercury.

Feb 27, 2013

By Bart Bartholomew, Randall J. Essex

INTRODUCTION In June of 2004, at the North American Tunneling Conference in Atlanta, an all-day workshop was conducted to review the application of Geotechnical Baseline Reports (GBRs) for underground construction. The moderator for the program was Bart Bartholomew, former President of Fruin Colnon Construction Company. The program involved commentary by a panel of engineers, owners, contractors, and legal representatives within the North American tunneling industry, as well as an extended audience discussion. The panelists were: Peter Douglass, President, Peter Douglass, Inc. Randall Essex, Executive Vice President, Hatch Mott MacDonald Joseph Gildner, Deputy Director for Technical Services, Sound Transit Randall Hafer, Esq., Kilpatrick Stockton Robert Fitzgerald Esq., Watt, Tieder, Hoffer, & Fitzgerald Kirk Samuelson, Senior Vice President, Kiewit Construction Group DEVELOPMENT OF PROGRAM FORMAT The focus of the program was to assess the state of the practice in the preparation of GBRs, and to discuss improvements that could and should be made with regard to their preparation, interpretation, and application. The approach used to achieve this focus in the broadest possible way was unique, in that it involved the panelists’ preparation of the workshop format and materials months before the presentation of the workshop. First, each of the six panelists was selected by the moderator based on their reputation and involvement in their respective fields of expertise, taking care to maintain balance and contrast within the collective pool of talent assembled. Following selection and agreement to serve on the panel, each panelist was asked to independently submit to the moderator a list of the six most pressing issues involving GBRs that they each frequently encountered in their individual professional experience. Each was asked to rank their issues in descending order of perceived importance. This process resulting in a pool of thirty-six potential or “candidate” issues for use in the workshop program. Contrary to the moderator’s expectations, there was surprisingly little duplication among the thirty-six issues submitted.

Jan 1, 2005

By B. Oraee

Tunnels as any other structures are affected by different loads and stresses. Generally, the loads on tunnels consist of both static and dynamic loads. These loads must both be considered in the tunnel design process. In this paper, the stability state of Jiroft water-transform tunnel is evaluated. Firstly, the in-situ stresses and then using Kirsch?s equations the induced stresses due to static loads in walls and crown of tunnel are calculated. Consequently, the strain caused by probable earthquake without considering the interaction between the concrete lining of tunnel and rock mass using seismic analysis is calculated based on free-field deformation. When the strain is determined, the simplified method of closed-form solution, Wang?s equations and Penzien?s equations are used to estimate the applied forces on the tunnel due to earthquake such as axial force and bending moment on a tunnel section taking into account the interaction of the tunnel concrete lining and rock mass. Results of this study show that the loads applied to the tunnel as a result of earthquake waves can be affect the stability of underground structures, especially long structures such as tunnels.

Jan 1, 2011

By H. Kinilakodi

The authors previously had developed a methodology that combines injury and citation measures into an overall mine safety performance evaluation tool, called the Safe Performance Index (SPI). It can be easily adopted by mine operators to monitor trends in their injury and citation experiences as a risk assessment method. In this paper, six normalized safety measures and the SPI are used to evaluate the risk that existed at mines in the two years preceding the occurrence of a fatality. The percentage of mines is given for which the risk was high or where trends of some of the safety measures indicated moderate risk. In 50% of the mines, this mine safety performance tracking method could have been helpful to the companies, state agency, or MSHA in recognizing and addressing emerging problems with actions that may have been able to prevent high-risk conditions, the fatality, and/or other serious injuries. The approach would have given scrutiny to the risk for mines that encompassed 74% of the fatalities during 2007-2010.

Jan 1, 2012

By J. Schenck

Goldcorp Inc. has mining operations and exploration projects throughout Canada, the United States, Mexico, Guatemala and Honduras; as well as partnerships in Argentina and the Dominican Republic. In rural areas of developing countries it is very common to have mining operations surrounded by diverse communities consisting of people with limited, or no formal education. This is fertile ground for anti-mining NGOs to cultivate. The limited educational backgrounds of the people, coupled with a company desire to maintain a low profile can lead to a problematic lack of trust between the local communities and the mining company. As part of its commitment to environmental stewardship and sustainable development, Goldcorp has implemented various programs to build trust at these operations, as well as incorporating this policy into any new projects prior to commencement of operations. This paper is intended to describe two initiatives that have shown positive results for both the communities and the Marlin Mine.

Jan 1, 2009

By R. Owen

The vision-based approach to process control involving fine particles in harsh on-line environments is discussed in this paper. The sensor equipment at the process location, consisting of a light source and a CCD camera provides RS-170 B&W video output. The video can be seen on a process monitor in the control room and is sent to a computer based Vision Processor. The Vision Processor contains a video digitizer and Canty developed software that extracts process information. The iron mine application controls thickener agent feed rate and thus settling pond overflow clarity. The sensor is mounted in the overflow flume of the outdoor settling pond and is used year around in the Minnesota weather. Alternate control system needs a low flow water sample which is subject to freezing in winter. The computer based vision processor provides 4-20 mA analog outputs for real time control as well as file archive for a history record.

Jan 1, 2001

By William H. Mount

Since the late 19405, St. Joe has operated rubber-tired, trackless mining equipment underground in its Southeast Missouri Lead Belt operations. At first, the trackless equipment was operated in conjunction with rail haulage equipment in the room-and-pillar operations, but was to later replace rail haulage completely. The first pieces of equipment to travel on pneumatic rubber tires were short-haul shuttle cars of 12-ton capacity hauling rock from the heading to the mainline railroad. Early-model drill jumbos were the next pieces of production equipment to be carried on rubber, along with mobile slusher ramps. Mobile diesel equipment, in the form of conventional rear-dump trucks, made its appearance underground in the early 1950s, introducing the era of relatively high-speed mobile equipment as compared to the electrically powered shuttle cars. Haulage distances for rubber-tired vehicles were no longer dictated by trolley lines and trailing cables and tires were subjected to increasingly severe applications. St. Joe's first completely trackless mine, the Hayden Creek Mine, was opened in 1952, employing rubber-tired drill jumbos, electric shuttle cars, and for the first time, an articulated diesel truck consisting of the tractor unit of a conventional earthmoving scraper and a rear-dump rock wagon. Those machines rolled on the first true earthmover tires to be used underground by St. Joe. The articulated truck concept proved to be very successful, and constitutes an In- creasing portion of the underground haulage today.

Jan 1, 1975

By J. C. Yingling, R. J. Sweigard, P. W. Conrad, J. M. Ringe, D. H. Graves

Much of the land reclaimed since enactment of the 1977 Surface Mining Control and Reclamation Act is over-compacted. Research has shown that excessive compaction in replaced growing media is detrimental to establishment of trees. If trees are to be grown on reclaimed surface mined sites, something must be done to alleviate this excessive compaction. Dry bulk density and penetration resistance are two soil parameters that can be used to indicate the level of compaction in reclaimed growing media. The University of Kentucky has developed test cells on reclaimed sites at a surface mine in eastern Kentucky to determine the impact of tillage (ripping) on soil compaction and tree survival rate. The ripping methods being evaluated include shallow tillage using conventional farm equipment and deep tillage using a dozer with a ripping arm. The impact of organic soil supplements on soil physical properties and tree survival rates is also being evaluated at the site. The organic soil supplements being evaluated include application of hardwood bark and application of straw and mulch. Each test cell has been planted with various species of trees, and for the first two years, data have been collected at these test cells for soil dry bulk density, penetration depth and resistance, and survival rate of trees. These data are currently being correlated to determine how ripping and the application of organic soil supplements affects the relationship between soil compaction and tree survival rate.

Jan 1, 2002

By D. C. Hogeman

Growing Greener is the single largest investment of state funds in Pennsylvania’s history, allocated to address the Commonwealth’s critical environmental concerns. Signed into law by Governor Tom Ridge on December 15, 1999, Growing Greener will enable the Department of Environmental Protection (DEP) to appropriate nearly $240 million over five years, to watershed restoration and protection, abandoned mine reclamation, and oil and gas well plugging projects. DEP has utilized these allocations in some remarkably innovative ways, as it: involves the cooperation of several state agencies, local governments, and grassroots organizations to address environmental concerns of the Commonwealth, provides funds directly to watershed groups based on locally determined decisions for local watersheds and offers a user friendly process. In three years, over $130 million in watershed restoration and improvement projects have been initiated.

Jan 1, 2002

By E. Hughes, D. Akers, D. Stopek

The Upgraded Coal Interest Group (UCIG), focuses on clean, low-cost options for coal-based power generation via pre-combustion, co-firing and reburn options. Its mission is to preserve and expand the economic use of coal for energy. By reducing the fuel costs and environmental impacts of coal-fired power generation, existing units become more cost effective and thus new units utilizing advanced combustion technologies are more likely to be coal-fired. Two great forces are reshaping the power generation industry, the Clean Air Act Amendment and deregulation of generation. The Clean Air Act Amendment is forcing change by making it necessary for power producers to plan for reducing emissions of sulfur and nitrogen oxides and possibly trace elements. At the same time, deregulation of generation is forcing utilities to focus their attention closely on the short term impact of any change on cost of power. Fuel is a utility's largest cost element; maximum fuel flexibility will be a utility's best weapon in an environment of rapid change. In a regulated environment, a utility was limited in how involved he might get into fuel supply, in a purely deregulated environment he need only be guided by the impact on the bottom line. It is clear that these two forces will promote a close look at factors such as coal upgrading which can have an impact on the availability of low sulfur coal or emission of NOX and trace elements.

Jan 1, 2000