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By J. F. Burr, D. P. Snyder, G. W. Luxbacher

"The Mine Improvement and New Emergency Response Act (MINER Act) of 2006 established the Office of Mine Safety and Health (OMSH) within NIOSH and provided authority for awarding contracts related to the development and implementation of new mine technology and equipment. Subsequently, Congress provided additional funding to NIOSH to initiate and continue the program. OMSHR has fulfilled this Congressional mandate through annual Broad Agency Announcement (BAA) solicitations, directed Requests for Proposals (RFP) and Inter-Agency Agreements (IAA), and has further expanded the program through capacity building BAA contracts with U.S. university mining departments in the areas of mine ventilation and ground control. This paper describes the extramural funding program and broadly examines the results of the 150+ contracts issued to date, grouped into key focus areas. INTRODUCTION The Mine Improvement and New Emergency Response Act (MINER Act) of 20061 established the Office of Mine Safety and Health Research (functioning as the Office of Mine Safety and Health Research or OMSHR) within the National Institute for Occupational Safety and Health (NIOSH), and provided authority for awarding contracts related to the development and implementation of new mine technology and equipment. The OMSHR external contracts program was formed in accordance with the MINER Act and has since issued over 150 contracts focused on worker health and safety. Initial funding for this program was provided by Congress through two Emergency Supplemental Appropriations (ESA) and was focused on emergency oxygen supply, communications and tracking, and refuge chambers (also referred to as refuge alternatives). Since the MINER Act, Congress has continued to fund the program through the annual NIOSH mining appropriation. The program was supplemented starting in 2009 with an academic capacity building program directed toward developing university tenure-track faculty and facilities and supporting graduate students in the area of mine ventilation; ground control was added as an additional focus area in 2011. A short synopsis of each contract is published on the NIOSH Mining website2 and final reports are available in digital form on request. A summary of the progress OMSHR has made over the 10-year period since the Act was published previously.3"

Jan 1, 2018

By E. R. Bauer

The ground control aspects and occupational safety concerns of extended depth-of-cut mining are presented in this U.S. Bureau of Mines (USBM) report. The scope of extended cut use and typical face operations while extracting extended cuts is reported. A comparative review of roof fall fatalities and a statistical analysis of accidents and injuries for both extended and nonextended cut mining is included. The views and opinions on extended cutting from a series of interviews with mine workers in five states are summarized. In addition, some of the problems and safety concerns of this extraction system are mentioned.

Jan 1, 1995

By R. Hardy

LaModel is a boundary-element program capable of calculating the displacements and stresses in thin bedded deposits such as coal, salt, or potash. Throughout its history, it has continually been upgraded in order to expand analysis detail and stay current with the latest advances in computer technology. The most recent enhancements include: an increased grid size capability, a significant increase in the speed of the automatic grid generation using an AutoCAD visual interface, implementation of subsidence-based horizontal strain calculations for multiple-seam situations, and pillar safety factor calculations. To demonstrate these new features, a multiple-seam case study of a longwall panel undermining an active set of main entries is presented.

Jan 1, 2006

By M. S. Klima, B. K. Kim

The use of a 25.4-mm- (1-in.-) diam water-only hydro-cyclone for separating liberated 125 x 25- µm high-density particles from similar-size lower-density (2.65 g/cc quartz particles, as might be used in soil washing applications, was investigated. As expected, cyclone performance was greatly affected by changes in cyclone geometry and operating conditions. A single-stage separation recovered 75% of the magnetite (4.8 g/cc) while rejecting nearly 60% of the quartz. With ferrosilicon (7.0 g/cc) as the heavy component, the recovery improved to 85%. The use of dense medium in a single stage increased both ferrosilicon recovery and quartz rejection to approximately 90% each. In addition, computer simulations of a three-stage circuit were performed. The simulations showed that recoveries approaching 97% with quartz rejections of 95% were possible.

Jan 1, 1999

By J. Humphries

With today?s turbulent markets and unprecedented global opportunities, the need to optimize net present value and internal rates of return from capital investments has never been greater. To help address the need, this paper presents an overview of the key processes and strategies for achieving maximum return from capital projects. Best practices discussed address stage gate management for project evaluation, selection, and oversight, project execution efficiency, value improving practices, operational readiness, and operational excellence. The paper also includes a model of key metrics and benchmarking with tips for application. [ ]

Jan 1, 2011

As opposed to a prescriptive-based design, a performance-based fire-protection system design allows the system planner the flexibility in choosing specific method, materials and design tools to achieve a preset goal. A different approach in fire protection and a powerful addition to existing method, the system has been around for many years, and has gone through numerous improvements. Despite its popularity in the building industry, it has not been introduced to the mining industry yet. As mines get deeper, increases in size and complication, mine fire safety system will also become increasingly challenging, a new and proven system should be able to great potential to eradicate many of the problems that are either unsolvable or cost-prohibitive with the traditional method. With increasing globalization and international exchange with other major mining countries a common language/practice also make the performance-based design method a desirable feature in mine fire safety system. This paper will first define a performance-based system, step-by-step design methods, likely impacts on fire-protection practices and possible challenges in implementing the system in US underground mines.

Jan 1, 2011

By A. Bobet

Design of a new underground laboratory is underway through the auspices of the United States National Science Foundation. The Deep Underground Science and Engineering Laboratory (DUSEL) is scoped to provide a diverse group of researchers with a dedicated underground facility capable of supporting a broad spectrum of fundamental and applied research at depth in the Earth?s crust. Key research partners in the endeavor are physicists, biologists, geoscientists and engineers. Engineers are not only designing the underground facilities, but are also actively involved in developing research initiatives. This paper will introduce the DUSEL engineering research program to the mining community, provide an overview of the site, geology, and laboratory facilities, and describe some key program initiatives. The particular technical challenges and opportunities afforded by the construction of DUSEL and the performance of the integrated science-engineering program will be discussed by reference to a subset of research initiatives that are currently under development: Cavern Design, CO2 Sequestration and Transparent Earth. These research initiatives target the development of new techniques that can support improved subsurface investigation, design and construction procedures. An increased use of the subsurface can actively contribute to the development of new, more sustainable solutions for use in mining and civil engineering practice.

Jan 1, 2011

By Robert M. Valentine, Randall L. Lentell

Interpretive geotechnical investigations were performed for the construction of approximately 15,250 m (50,000 ft) of wastewater interceptor tunnels in Austin, Texas. Subsurface materials consist of claystone (or clay shale), siltstone, altered volcanic tuffs, chalk and limestone. Special conditions include multiple crossings of Onion Creek with cover ranging from about 1/2 to 3 m (2 to 10 ft.), and the potential for mixed-face conditions consisting of water-bearing gravels overlying clay shale or siltstone. The methods and results of the geotechnical investigations are discussed and the inferred construction conditions are compared to those encountered during tunneling. A suggested format is presented for interpretive geotechnical reports for underground construction projects.

Jan 1, 1985

By Steve Kral

The mining industry in northern Ontario is known mostly for its huge nickel deposits. Inco’s and Falconbridge’s nickel mines in the Sudbury Basin are the best known. And with nickel prices being what they are, interest in the region continues. And how. Inco and Falconbridge want to merge. Teck Cominco wants Inco, but without Falconbridge. Xstrata made a hostile bid for Falconbridge, which Falconbridge rejected. And, in June, Phelps Dodge trumped them all when it made an approximately US$40-billion friendly offer for Inco and Falconbridge in a two-part deal.

Jan 1, 2006

By K. F. Bailey

Naturally occurring asbestos in aggregate and other mineral deposits, and the release of asbestos fibers into the ambient environment, is a public health concern. Determining the presence of asbestos in an ore body also presents a considerable sampling and analytical challenge. Improper and inaccurate identification of asbestos can result in unwarranted public and worker panic leading to significant costs to mine operators both in terms of dollars and company image. Some companies have been forced out of business simply because they had the non-asbestiform, prismatic variety of one of the six asbestos minerals. In the late 70’s, asbestos was found as a contaminate in a trap rock quarry in Rockville, Maryland. This discovery led to a massive overreaction by federal, state and local governments. In 1986, the Occupational Safety and Health Administration (OSHA) promulgated a final rule that regulated the common non-asbestiform mineral habits of actinolite, tremolite, and anthophyllite as if they were asbestos. The rule was reversed after a six-year struggle. Recently, the Libby, Montana, W. R. Grace vermiculite - asbestos, as well as the California chrysotile in serpentinite, and the New Jersey Southdown quarry – asbestos events have rekindled the entire issue of naturally occurring asbestos. It is time to get this concern addressed with sound science so that real asbestos is properly identified and controlled.

Jan 1, 2002

By M. Arias

"An attractive foreign investment legislation, an anti-mining framework in the jurisdiction where a head office is located, the geographical location of the mineral resources, a country that offers the technology needed by the industry for its operations -- these are some of the many factors that make mining and mineral exploration a global business. It is precisely in the complexity of this new era of globalization and market environment, that sustainability initiatives are challenged. Responsible management of mineral exploration and mining is no longer defined by the use of efficient technology and resource management. Sustainability is not only a report compliance exercise or a green revolution. Sustainability is like any business, a long term profitable proposition. This new approach encompasses four pillars: social, economic, environment, and culture. This new approach connects humans and corporations; it is the way to engage, respect and improve relations with the people with whom we work and our neighbours."

Jan 1, 2011

By Hiroshi Soda, Atsumi Ohno, Hiroyuki Yamazaki, Alexander McLean

INTRODUCTION The method of heat removal during a casting process strongly influences the crystal morphology of the cast product and hence the metallurgical and mechanical properties of the solidified materials. In this paper, the Ohno Continuous Casting Process (OCC) is described in terms of the casting conditions and the type of structure observed in the cast product. Significant improvements are observed in workability, fatigue strength and corrosion resistance of castings produced by the OCC method, Ohno (1988). Applications of this technique to low melting point nonferrous metals and alloys are discussed. The feasibility of the application of this technology to high melting point materials is outlined. THE OCC PROCESS The OCC process involves delivering liquid metal into a heated mold, the temperature of which is held just above the solidification temperature of the metal to be cast. This is the key point which differentiates the OCC process from the conventional continuous casting method. A schematic illustration of the OCC process is shown in Figure 1. The Formation of a Single Crystal When the mold is heated above the solidification temperature of the metal to be cast, nucleation on the mold surface is prevented and solidification takes place only at the mold exit. The heat is extracted through the product being cast by a cooling device located near the mold outlet. Crystals are formed only at the tip of the dummy bar at the start of casting, and as the dummy bar travels away with a progressively increasing speed from the mold, the position of the solid liquid interface will align with the mold exit, producing a unidirectionally

Jan 1, 1990

By N. Duru, C. Nesbitt

During the cyanide leaching process, gold and silver ores that come from the transition zones, which typically contains low levels of sulfide, may produce one or more of the following reduced sulfur species: sulfide ( HS−), polysulfides ( Sn 2−), thiocyanate ( SCN−), thiosulfate ( S2O3 2−), trithionate ( S3O6 2−), tetrathionate ( S4O6 2−), pentathionate ( S5O6 2−), hexathionate ( S6O6 2−). The actual speciation of the reduced sulfur species in the circuits will primarily depend on the redox potential, pH, cyanide levels, and existing sulfur species in recycled process water, as well as the presence of other reactive metal species. The development of an accurate analytical method for sulfur species in cyanide leaching units of gold ores where sulfur speciation occurs has an important role in explaining the metal recovery deviations. This study presents the speciation of sulfur species and the development of ion chromatography method to analyze reduced sulfur species thiocyanate ( SCN−), thiosulfate ( S2O3 2−), trithionate ( S3O6 2−), tetrathionate ( S4O6 2−) in cyanide leaching circuits for gold ores. The method developed has resulted in precise quantification of target sulfur species in leach solutions. Method development and validation results were illustrated on analytical graphs containing each species’ peak number, retention time (min), type, width (min), area (mAU*s), height (mAU), and area distribution (%) of the peak.

Mar 2, 2024

By Nikhil Dhawan, Veeranjaneyulu Rayapudi

This study investigates upgrading of low-grade banded hematite quartzite iron ore (Fe ~31%). Conventional beneficiation was found to be futile. The susceptibility of iron phases to microwave exposure and their selective absorption assists in the liberation of iron values. Microwave exposure of coarse particles at 540 W for 10 min yielded a concentrate with Fe 56.30% and recovery of 50.68%. Conventional carbothermic reduction at 500 °C, 60 min and 9% charcoal yielded a concentrate with Fe 57.6% and iron recovery of 68%. The presence of sufficiently bonded silica leads to an easy formation of a fayalite phase. The microwave reduction design yielded FeG of 57.6%, FeR of 47% and a yield of 24% at an optimal condition of 540 W, 8 min and 6% charcoal. It was found that a small fraction of microwave-irradiated ore-charcoal mixture melted rapidly, and pure ferrite balls were observed within 8 min. An optical micrograph of a ferrite ball reveals the retained austenite and martensite phase.

By Henry O. Ash

On June 16, 1982, Rio Blanco submitted a request to the US Minerals Management Service for a suspension of operations under its federal oil shale lease. The company also wanted a five-year delay in the requirement for further minimum royalty payments and a five-year extension of the primary lease terms of 20 years. The request was granted in late July in the midst of yet another slump in oil shale activity. Rio Blanco holds one of four Federal oil shale leases that were granted under the Interior Department's Prototype Oil Shale Leasing Program in 1974. That year the DOI offered for lease six federal oil shale tracts, two each in Colorado, Utah, and Wyoming. The leases in Colorado and Utah were granted for substantial bo¬nus bids as shown in Table 1, but the Wyoming tracts had no takers. In the eight years hence, no oil shale has been produced commercially. Indeed, the prospects for successful oil shale development have fluctuated widely, continuing a 60-year- old cyclical pattern in the fledgling industry. The prototype program was developed and initiated while this infant industry struggled to begin anew, without the benefit of any federal oil shale leasing regulations, or any history of federal oil shale leasing at all. Permanent regulations were not required because the effort was limited and designed to provide the foundation for any future leasing program. Section 21 of the Mineral Leasing Act of 1920, a Nov. 30,1973 Federal Register notice, and the leases themselves constitute the legal and regulatory framework for leasing and developing prototype oil shale tracts. The prototype leases contain some unusual provisions including installment payments of the bonus bids, credit of early development costs against payments due the government, adjustment of royalty rates according to regional crude oil price fluctuations, and unusually extensive and detailed environmental stipulations. Several of the provisions were intended to provide incentives for early development and financial penalties for failure to develop. The requirement for minimum royalty payments in lieu of actual production royalties beginning in the sixth year of the lease falls in the latter category. After the sixth year, the required minimum payment is increased east year through the 15th year by an increment equal to that due in the sixth year. The minimum royalty then remains the same through the final five years of the primary lease term. Minimum royalty is calculates on a different production level for each prototype lease, based on the quantity of 125 L/t (30 gal/st) shale estimated to be recoverable from. each tract by room-and-pillar mining. That mining system was selected for reference as the only proven extraction method for oil shale at that time (early 1970s) The minimum royalty (production) rate was calculated for each tract by direct comparison of its estimated recoverable 125-L (30-gal) resource to a hypothetical tract containing 1.9 Gt (2.1 billion st) of recoverable 125-L (30-gal) shale. For the hypothetical lease tract, the minimum production for the sixth year was calculated to be 3.2 kt/d (3,500 stpd), increasing by a like amount each lease year through the 15th to a daily production rate of 31.7 kt (35,000 st). Under this formula, the hypothetical lease tract would yield $16 million in minimum royalty payments over the 20-year primary lease term if there were no production, no development credits taken, and no adjustment of the royalty rate due to fluctuation of regional crude oil prices. The production rate of 31.7 kt/d (35,000 stpd) was a somewhat arbitrary figure that was considered, in the early 1970s, to represent a minimum size for a commercial oil shale operation. A production rate of 7.9 dam3/d (50,000 bbls/day) soon supplanted that smaller mine production figure as a rule of thumb for the minimum size for a commercial facility. The proportional relation-

Jan 11, 1982

By Geoffrey Berry

Exposure?response relationships between the relative risk of lung cancer and quantitative measures of exposure to asbestos are available from a number of epidemiological studies. Meta-analyses of these relationships have been published by Lash et al. (1997) [Lash, T.L., Crouch, E.A.C., Green, L.C., 1997. A meta-analysis of the relation between cumulative exposure to asbestos and relative risk of lung cancer. Occup. Environ. Med. 54, 254?263] and Hodgson and Darnton (2000) [Hodgson, J.T., Darnton, A., 2000. The quantitative risks of mesothelioma and lung cancer in relation to asbestos exposure. Ann. Occup. Hyg. 44, 565?601]. In this paper, the risks derived in these meta-analyses have been compared. Lash et al., concentrated on process and found that the risk of lung cancer increased as the asbestos is refined by processing. Hodgson and Darnton concentrated on fibre type and found that the risk was highest for exposure to amphibole asbestos (crocidolite and amosite), lowest for chrysotile and intermediate for mixed exposure. Some of the differences between the conclusions from the two meta-analyses are a consequence of the choice of studies included. The range of asbestos types included in the studies in the analysis of Hodgson and Darnton was wider than that in Lash et al., enabling differences between fibre types to be analyzed more readily. There are situations where occupational exposure to chrysotile asbestos has shown no detectable increase in risk of lung cancer. Taconite miners have shown no increased risk of mortality due to lung cancer. © 2007 Elsevier Inc. All rights reserved. Keywords: Mesothelioma; Amosite; Grunerite; Taconite; Crocidolite; Tremolite; Anthophyllite; Winchite; Risk assessment; Etiology

Jan 1, 2007

By W. Belobraidich

Kennecott's Ray mine is located about 145 km (90 miles) north of Tucson in the Mineral Creek mining district of central Arizona. Mining in the district started in the late 1800's. The Ray mine itself was first mined by under- ground methods in 1911 and was changed to an open-pit operation in 1952. Mineralization is complex and includes sulfide, silicate, and native copper mineralization, as well as minor amounts of molybdenite. Sulfide ore, mined at Ray, is shipped by rail to Kennecott's concentrator and smelter at Hayden, 32 km (20 miies) away. Silicate ore, mostly chrysocolla, is processed near the mine in a vat leaching-electro- winning plant. The mine consists of two sulfide areas: (1) the West pit and the Central pit (the original Pearl Handle pit) and (2) a silicate area on the northeast perimeter of the Central pit. The pit now is over 304 m (1000 ft) deep and approximately 3048 m (10,000 ft) long. Roads within the ultimate pit are limited to a grade of 10%, while those outside the pit are limited to 8%. The mining equipment consists of 40 Wabco 1094 (120-st) haulage trucks [ranging from 109 to 227 t (120 to 250 st)], 12 electric shovels [ranging from 6 to 23 m (7 to 25 yd)], and 3 11-m (12-yd) Dart production loaders.

Jan 1, 1979

By H. R. Hernandez-Guerrero, S. A. Robles-Salazar, M. Marín-Pasillas, P. J. Pompilla-Rosales

Peña Colorada is a company dedicated to the exploration, exploitation, and beneficiation of iron ore, serving the national steel industry. Established in 1975 as a stateowned enterprise, it transitioned to operating as a private organization in 1991. It is jointly owned by two investors, ArcelorMittal and Ternium, each holding a 50% stake. The mining operation is situated in the municipality of Minatitlan, in the northwestern part of the state of Colima, Mexico (Figure 1). It comprises an open pit mine and a concentrator, covering an area of approximately 2,300 hectares. The pellet mill is in the town of Manzanillo, Colima state, a port on the Pacific coast, about 46 km southwest of the mine. The pellet mill occupies its own property with a total area of 60.4 hectares. A gravity-driven concentrated slurry pipeline connects the mine and the pelletizing plant, located at an average elevation of 1,020 meters above sea level and 20 meters above sea level, respectively. Currently, Peña Colorada produces 4.1 million tons of pellets and 0.4 million tons of iron concentrate annually. In 2018, due to a change in the cutoff grade, the processing volume of the beneficiation plant increased from 9 million tons to 16 million tons annually. This led to a greater amount of information to process and characterize the ore extracted from the pit before its processing in the beneficiation plant. Consequently, Peña Colorada sought new ore control technologies to enhance ore selection, optimize human resources and data management, as well as minimize discrepancies between planning and execution. To ensure adherence to quality agreements with stakeholders, it is crucial to understand the ore characteristics before initiating mining activities.

Feb 1, 2024

By John R. Marks

The first 0.7 m3 (1 cu yd) diesel load- haul-dump vehicle (LHD) arrived at the Homestake Gold Mine in Lead, SD in I969 to muck a ventilation drift. Others soon followed. Mechanization has subsequently changed stoping methods, manpower requirements, ventilation practice, the definition of minable reserves, and it has impacted safety and health. These have all had a direct bearing on the economics of producing gold ore from deep underground. Mechanized mining Before mechanization, production quotas at Homestake were met by several open cut-and-fill (OCF) mining methods. OCF mining relied on jackleg and wagon drilling, electric and compressed air slushing and cribbed raises brought up through the fill. Even square- set stoping was used until about eight years ago. The mine became 100% mechanized in 1988. The two current stoping methods are mechanized cut-and-fill (MCF) and vertical crater retreat (VCR). In 1992, MCF accounted for 54’S, VCR for 44% and development/uphole for 2% of the 1.4 Mt (1.55 million st) of underground ore produced. These methods are typically ramp- based and use diesel-powered LHDs, trucks, pneumatic drill jumbos and utility vehicles. Electric LHDs and rubber-tired compressed air muckers have also been used in VCR scrams. Pfarr (1991) and Mitchell (1980) provide good overviews of current production methods.

Jan 1, 1993

By Gary B. Hemphill

The 345 km long Taiwan High Speed Rail Project will connect the island’s two most populated cities, Taipei and Kaohsiung. Kaohsiung is the world’s third busiest port. The 23 km of alignment on Contract C230 requires the construction of 5,879 m of shallow mined tunnels ranging from 137 m to 1,285 m in length. All nine of these tunnels are mined using NATM methodology. Two of the tunnels, T01 and T08 are in the Toukoshan Formation. This paper will discuss the mining methods, ground support design, and the instrumentation installed to monitor and verify its effectiveness in the two aforementioned tunnels.

Jan 1, 2003