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Breaks in coal slurry impoundments can threaten the lives and health of area residents, destroy homes and businesses and contaminate water supplies. This dangerous potential looms over coalmining regions in West Virginia and throughout Appalachia. The Coal Impoundment Project was begun in June 2003 to provide an inventory and mapping of active and abandoned impoundments in West Virginia. The project also provides the public with specific information about the impoundments in their communities. It is dedicated to alerting residents of danger and evacuation plans, reducing risk to residents and finding alternatives to impoundments. Since its first year, more than 100 impoundment sites have been added to the project’s Website.

Jan 1, 2005

By Carsten Rühlemann, Thomas Kuhn, Cornelia Kriete

"Any economic calculation with respect to potential submarine mining activities requires reliable analytical data on the contents of valuable metals in these ores, including trace metals such as rare earth elements as well as Ti, Mo, V, Zr and Li. Due to the very special matrix of ferromanganese nodules (30% manganese oxides, 10-20% iron oxides, silicates; see Kuhn et al., this volume), their geochemical analyses pose a real challenge. Available ferromanganese nodules reference materials, e.g., NOD-P1 and A1, JMn-1, GBW07249, SDO-4 to -7 and NM2388, generally have only a few certified values for trace elements. Published data for these reference materials, collected in the GeoReM database (http://georem.mpch-mainz.gwdg.de/) are either rare for high technology metals or widely scattered for certain elements, especially the PGEs. Since most of these materials were released in the 1990s, many analytical procedures have seen significant advancement.In order to facilitate analytical quality assurance during exploration and potential future mining activities, the German Federal Institute of Geosciences and Mineral Resources (BGR) has contracted the Central Geological Laboratory of Mongolia (CGL) to produce a certified reference material for nodule analytics. Certified reference materials provide the highest level of reliability in geo-analytical measurements currently available and the CGL has a long-term experience in producing geological reference materials. Recently, the CGL was accredited as a reference material producer according to ISO Guide 34 by the American organization ACLASS (Assured Calibration and Laboratory Accreditation Select Services). Furthermore, it has been accredited as a testing laboratory according to ISO 17025."

Sep 1, 2014

By K. Oraee

Mining of copper ore and the related industries play an important role in Iran?s economy. Copper ore production in Iran accounts for 75% of the total production in the Middle East. All activities related to copper, that is, exploration, production, refinement etc are owned and managed by state owned companies. Decisions have been made to privatize all these activities. To assess the success of this privatization process, different components of the industry must be subject to economic analysis. In this paper, the cost estimation of all operations has been carried out. The total potential and attainable revenues have also been estimated using historical data available from the industry. Risk is a major factor in all mining activities and the copper industry of Iran has been subject to risk factors arising from many internal and external variables. These variables have been recognized and their effects evaluated. The effect of risk on the economic feasibility of the operations in the industry has also been analyzed.

Jan 1, 2011

By J. Harrison Daniel

Were the legislators and politicians responsible for the closing of the U.S. Department of the Interior?s Bureau of Mines (Bureau) in March 1996 fully aware of what they were doing? Throughout the United States? history, the domestic mining and minerals industry has been largely responsible for the nation?s growth and prosperity that had made it a world leader. The mining and minerals industry made it possible for the young nation to catch up with Europe during the Industrial Revolution, played an essential role leading to victories in World Wars I and II and was a core ingredient for continued economic growth. For a number of decades, America?s import dependency on non-fuel mineral materials has continued to increase. (USGS Mineral Commodity Summaries). Developing domestic resources to meet current and future demands ? particularly those resources considered to be of strategic and critical value to national security ? is necessary. Federal involvement is required since many of these resources are located on public lands. Another reason for federal involvement is that the success of the industry depends on long-range research programs and advances that may take up to 25 years to become commercially available. This situation requires federal partnership to coordinate the programs necessary to collectively involve the industry, individual mining companies and colleges and universities. So, how was it possible to close a federal agency that had contributed so much to the nation?s welfare in a mandated 90-day period, with more than 1,200 employees losing their jobs?

Jan 4, 2010

By P. T. Bissert, T. J. Lutz, J. A. Yonkey, G. T. Homce

"The U.S. National Institute for Occupational Safety and Health (NIOSH) has been researching refuge alternatives (RAs) since 2007. RAs typically have built-in pressure relief valves (PRVs) to prevent the unit from reaching unsafe pressures. The U.S. Mine Safety and Health Administration requires that these valves vent the chamber at a maximum pressure of 1.25 kPa (0.18 psi, 5.0 in. H2O), or as specified by the manufacturer, above mine atmospheric pressure in the RA. To facilitate PRV testing, an instrumented benchtop test fixture was developed using an off-the-shelf centrifugal blower and ductwork. Relief pressures and flow characteristics were measured for three units: (1) a modified polyvinyl chloride check valve, (2) an off-the-shelf brass/cast-iron butterfly check valve and (3) a commercially available valve that was designed specifically for one manufacturer’s steel prefabricated RAs and had been adapted for use in one mine operator’s built-in-place RA. PRVs used in tent-style RAs were not investigated. The units were tested with different modifications and configurations in order to check compliance with Title 30 Code of Federal Regulations, or 30 CFR, regulations. The commercially available relief valve did not meet the 30 CFR relief pressure specification but may meet the manufacturer’s specification. Alternative valve designs were modified to meet the 30 CFR relief pressure specification, but all valve designs will need further design research to examine survivability in the event of a 103 kPa (15.0 psi) impulse overpressure during a disaster. BackgroundThe Mine Improvement and New Emergency Response Act of 2006, known as the Miner Act (U.S. Department of Labor, 2006), was enacted in the wake of three mine accidents involving explosions or fire that claimed 19 lives that year. Intended to help improve underground coal mine accident preparedness, the Miner Act includes provisions that target mine safety issues in areas such as emergency response planning; adoption of new technology; training and education; and mine safety standards enforcement. Section 13 of the Miner Act specifically directed the U.S. National Institute for Occupational Safety and Health (NIOSH) to provide for research into the effectiveness and viability of refuge alternatives (RAs) for underground coal mines, and the U.S. Department of Labor to act on the results of such research, as appropriate. These mandates culminated in the 2009 adoption of changes to the Title 30 Code of Federal Regulations, or 30 CFR, mining health and safety regulations (U.S. Department of Labor, 2008), requiring underground coal mines to supply mine emergency RAs and associated components so as to provide a life-sustaining environment for persons trapped underground. Such RAs can be either selfcontained mobile units or built-in-place facilities. The regulatory changes also include provisions establishing requirements for the approval of RAs and their components by the U.S. Mine Safety and Health Administration (MSHA), among which are numerous criteria for providing a safe breathable atmosphere under positive pressure within the RAs. One criterion for maintaining a safe RA atmosphere is the inclusion of an air pressure relief valve that will activate at a maximum of 1.25 kPa (specified as 0.18 psi, or approximately 5.0 in. H2O), or as specified by the RA manufacturer, above mine atmospheric pressure in the RA (U.S. Department of Labor, 2008)."

Oct 1, 2016

Newcrest Mining is one of the leading independent gold producers in Australia thanks in large part to its Cadia Valley operations. It is the largest gold and copper producer in New South Wales and one of the largest in Australia. This year Newcrest will expand its operations with a A$545-million expansion in the area. The Cadia Valley is approximately 250 km (155 miles) west of Sydney. The province presently includes the Cadia Hill opencut mine and the Ridgeway underground mine. With a significant mineralized system to the east of Cadia Hill and a mineral resource below Ridgeway, Cadia Valley has the potential to underpin Newcrest?s production for up to 30 years. In 2007, total gold production for the company in-creased to more than 50 t (1.6 million oz) and cash flow increased by 47 percent, according to the company?s annual report. The history of mining in the area dates back to 1851, but Newcrest?s history is young. In 1990, Newcrest commenced activities in the Cadia Valley. In 1992, Cadia Hill was discovered, with the discovery of Cadia East (1995) and Ridgeway (1996) following close behind. In 1998, the Cadia Hill openpit mine was commissioned. In 2002, the Ridgeway underground mine was commissioned and in 2007 the company?s board of directors approved an A$545 million development of the Ridgeway Deeps. The Ridgeway underground mine is located adjacent to Cadia Hill. The Ridgeway orebody has no surface expression but lies approximately 500 m (1,640 ft) below the surface and resembles an inverted teardrop. It measures approximately 450 m (1,476 ft) by 250 m (820 ft) and extends in excess of 850 m (2,788 ft) in depth. Ridgeway is a sublevel caving operation. Crushed ore from underground is delivered by conveyor to a surface stockpile, adjacent to the Ridgeway concentrator. Using similar processes to the adjacent Cadia Hill concentrator, gold and copper are recovered in a conventional flotation circuit to produce a copper concentrate containing elevated gold levels. Ridgeway concentrate is combined with the Cadia Hill concentrate before it is pumped to the filtration plant in

Jan 1, 2008

By Ross W. Smith, Xiapeng Zheng, Merrill P. Allen

The results of flotation of a primary desliming hydrosizer overflow material containing 14.6 wt.% P20, and 3.6 wt.% MgO are presented. The phosphate minerals were collophane and francolite and all minerals appeared to be liberated. The material had not been previously treated with flotation reagents. In the experimentation, various collectors were evaluated for effectiveness. The relative effectiveness of flotation in different flotation devices was determined. Finally a two-stage flotation scheme is proposed using column flotation of dolomite in the first stage and Denver cell flotation in the second.

Jan 1, 2002

By J. W. Hawkins, K. B. C. Brady, K. Miller, J. Cuddeback

Remining of abandoned coal mines in Pennsylvania requires the implementation of pollution abatement and mining techniques called Best Management Practices (BMPs). Water-quality data from over 100 remining sites with more than 230 abandoned discharges were analyzed with respect to the types of BMPs employed to abate the pollution loadings of acidity, iron, manganese, aluminum and sulfate. Discharges exhibiting a significant decrease in acidity were most highly associated with sites where large volumes of alkaline materials were encountered (66.7%) or added (63.7%). The best results for iron loading were achieved with large-quantity alkaline addition (54.6%) and water handling systems (47.8%). Water handling systems (47.4%), daylighting (40.7%), and revegetation (40.2%) were associated with significantly lower manganese loadings. The decreases in acidity and sulfate loads associated with increasing the amount of alkaline material in the backfill indicates that the production of acid mine drainage can be retarded by adding large quantities of alkaline materials.

Jan 1, 2002

By D. H. Horswill

Red Dog, the world’s largest zinc mine, is located ninety miles north of the Arctic Circle in northwest Alaska on lands owned by the Inupiat Eskimo organization called NANA. NANA received a subsurface title over this resource as part of their settlement lands under the Alaska Native Claims Settlement Act and subsequently entered into a Lease Agreement with Cominco in 1982. Cominco, an international mining company focused on zinc, built and operated the mine. NANA’s principle objective in the development of the mine was to have it contribute to the development of sustainable communities within their traditional region. This meant creating job opportunities in a modern economy while preserving the traditional subsistence lifestyles. Preservation of their culture, language, and traditions are as important to the NANA people today as they were through ages past. The principles of sustainable development – matching economic, environmental, and social goals through continuous communications and high commitment to efficient and effective operations – have been core values for the Red Dog Mine from the beginning. This paper will describe how a large mining operation in a remote corner of the world has been able to contribute toward sustainable development in that region.

Jan 1, 2000

By Steve Kral

Globalization was the key word for the mining industry during the 1990s, just as productivity was the key word of the 1980s. And globalization will remain the key word as the industry enters the 21st century, according to speakers at the Colorado MPD Meeting held in Colorado Springs, CO in May. The meeting, put on by the Colorado Section SME Minerals Processing Division, drew about 120 people to the Broadmoor Hotel. “Operating Globally” was the theme of the 49th annual conference. Speakers addressed the reasons why mining companies have limited their spending in the United States and have moved into Third World and developing nations.

Jan 1, 1999

By Eugie Kabwe

The effective employment of a pretensioned bolt within support structures requires an appropriate installation tension as a result of sufficient bolt head/nut preload. In this paper, a load indicator washer (LIW) able to withstand an assigned static loading as well as provide an appropriate pretension is presented. The different LIW breadths are numerically analyzed with ABAQUS finite-element code to estimate deformation when a designated 60 kN preload is applied. The numerical simulation employs the bilinear isotropic hardening constitutive law governed by the von Mises yield criterion. The simulation also considers the nominal temperature of the nut-LIW-rock bolt connection. Therefore, long-term relaxation effect on bolt pretension as a result of stress relaxation is neglected. The compressive force required to achieve the LIW predetermined deformation is the bolt pretension. It is drawn from the simulation results that LIWs with thicknesses of 1.5, 2.0, 3.0, 3.5 and 4.0 mm are completely flattened when subjected to 28, 42.5, 65, 76 and 88 kN preloads, respectively.

By Earl Rau

Introduction Will cogeneration be a major power source in the future? The location of electric power generating plants has changed. In 1900, more than 50% of electricity was generated by industrial plants. Since then, industrial plant generation of electricity greatly decreased to 17% in 1950 and to only 3% in 1980. Changing economics in electric power generating costs, though, may allow cogeneration to reverse this trend. Cogeneration has been defined as the simultaneous production of electric (mechanical) and thermal energy from a single energy source. Some applications are considered to be byproduct generation of electricity from industrial, thermal operations. Cogeneration is not new to the mining and minerals industry. Smelters and steel mills have used waste heat to generate electricity. Public Utilities Regulatory Policies Act of 1978 The potential for increased industrial cogeneration of electricity is related to the March 9, 1978 enactment of the Public Utility Regulatory Policies Act (PURPA). The US Supreme Court ruled that PURPA is constitutional. The court upheld requirements that utilities interconnect to cogenerators. It also ruled that 100% of avoided costs be used as the guideline for electricity sales by a qualifying facility (QF) to a utility. The state of New York established a floor price $0.06/kWh for electricity sales from a QF to a utility. It is obvious, then, that a cogenerator must first establish price and then become a qualifying facility in order to sell electricity to a utility. Proposed cogeneration plants The estimated industrial cogeneration potential for the years 1986 to 2000 is 9500 to 25,000 MW. Industries represented in this cogeneration estimate are pulp and paper, petroleum, chemicals, food, textiles, rubber, plastics, steel, lumber and wood, cement, glass, metal fabrication, and industrial parks. A cogeneration plant has been proposed for the Union Carbide chemical plant in Institute, WV. A steam turbine/generator would be installed to replace the pressure-reducing valve in the 2.7 MPa (400 psig) header. Scott Paper Co., Mobile, AL, proposed a cogeneration plant using a coal- and wood-fired boiler and a turbine/generator to produce process steam and electric power. A cogeneration system has been proposed for a large oil refining plant. A pulverized coal boiler would produce high-pressure steam to operate a turbine, generator. The exhaust steam from the turbine will go to the process and an existing turbine. Kansas City, MO's Armour meat-processing plant has proposed a cogeneration plant. This proposal is to use a natural gas or oil-fired, gas-driven turbine and a generator. The waste heat from the gas turbine would go to a heat recovery boiler for use as process heat. Dade County, FL is implementing a central energy system to supply electricity, air conditioning, and domestic hot water for five buildings in downtown Miami. The cogeneration system is to provide flexibility, to optimize fuel use efficiency while serving the variable thermal demands. Generation of electricity from municipal waste is not considered to be a cogeneration process but is covered by PURPA. Special considerations are provided for waste/electric power generation to encourage the development of these systems. ?

Jan 7, 1987

By H. Walqui

The Empire concentrator was built in four stages, with the latest stage accounting for 50% of the overall plant capacity. Over the past 5 years, the average throughput of the three grinding lines has decreased by 50 LTPH (15%) without significant changes in ore characteristics and despite the addition of secondary grinding capacity to supplement the existing pebble mills that are the constraint of the grinding circuit. This paper discusses the different areas under study that are aimed at optimizing grinding circuit utilization which includes improving system logic, pebble crushing operation and pebble mills operation.

Jan 1, 2009

By James S. Redpath

"The ways of the world be many and most of the ways be tried, you follow in the footsteps of others till you come to the great divide". These words, written by Robert Service a long time ago, come to mind when I think of our original attitude upon entering into a contract with the International Nickel Company to sink the deepest shaft in the world outside of the Union of South Africa. This shaft was to be sunk to a depth of 7,137 feet from surface, and while it was recognized by all concerned to be a somewhat unusual undertaking in our part of the world, the fact that quite a few shafts had already been sunk to this depth in South Africa probably gave us the feeling that we were following in the footsteps of others. In retrospect, because this shaft was being sunk under entirely different conditions than those existing in South Africa, we were in fact venturing into an entirely new area of endeavour without properly recognizing this fact. It has occurred to me that others considering a similar type of job could benefit from our experience, especially in an assessment of the risks involved and how they compare to those encountered in an ordinary shaft. For comparison purposes, I would define an ordinary shaft as being sunk to a depth of 5,000 ft or less, and a deep shaft as one being sunk to a depth of between 5,000 ft and 8,000 ft. The sinking of the Creighton No. 9 Shaft has been de-

Jan 1, 1997

By M. Grun, A. C. Marlowe, I. Littleford

SYNOPSIS A Wirth tunnel borer owned by Anglo American Corporation completed a 1150m long tunnel some years ago and was subsequently extensively modified by Technical Development Services. In 1982 this borer provided new and particularly interesting information In the field of hard rock boring. The abrasive quartzltes traversed proved to be a challenge to the cutter manufacturer and the project team. This paper examines the problems faced, the solutions found and the lessons learnt.

Jan 1, 1983

By B. Grosso

The National Italian Regulation concerning environment protection imposes that industrial areas are provided with systems aimed at preventing the circulation of contaminated groundwater. These systems can be static or dynamic and operate basically by intercepting the contaminated flow. Their effectiveness, realization time and costs depend on the intervention type and on the features of the specific site. The selection of the best solution is complex and the results obtained by this selection may be affected by residual risks related to the uncertainty of the hydrogeological and geotechnical characterization of the site. With regard to the industrial area of Portovesme, located in the south of Sardinia, the paper presents the analysis of alternative interventions aimed at the protection of the groundwater. The attention is focused on the evaluation of their effectiveness, impact on environment and, finally, time and costs of construction.

Jan 1, 2008

By Syd S. Peng

Is the laboratory sized coal specimen much stronger than underground coal pillars? The answer to this question has a profound implication to many coal operators. It will decide how much of the coal reserve can be recovered. Or, in many cases, it will determine whether it can be mined economically. Recent trends in several eastern states to establish regulations regarding coal pillar design to prevent surface subsidence long after mining heighten the debates. And, in some cases, these trends highlight the existing practices that seriously question the conventional wisdom. Currently, nearly all researchers and practitioners agree that as the size of rock specimens increases, its strength decreases. This concept has been universally adopted as the basic principle for coal pillar design in the United States. Several formulas have been derived to account for this effect. The reduction factor for underground coal pillars ranges from one-half to one-sixth of the strength obtained in the laboratory, depending on the formula selected. Recent case studies indicate that the reduction factor is not justifiable, at east in some cases. The use of a reduction factor is based on the assumption hat smaller rock specimens as tested in he laboratory contain none or fewer fractures or planes of weakness than larger specimens or underground coal pillars. In other words, the larger the rock materials, the more fractures it contains and subsequently weaker in strength. Do all underground coal pillars have more fractures than laboratory sized coal specimens? Not necessarily. All coal contains cleats. Some are con¬spicuous but others are not. In terms of cleat density (number of cleats per unit area), there is no difference between an underground coal pillar and a laboratory sized specimen, provided the specimen size is larger than the cleat spacing, which is mostly 25 to 75 mm (1 to 3 in.).

Jan 1, 1993

By V. E. May

Has your organization adopted Six Sigma as part of their Performance Improvement strategy? What about Lean manufacturing or Lean Six Sigma? If you already have any of these business process improvements in place where will you go next? In this article we will focus on transforming your organization beyond Lean Six Sigma to the next level of performance. In the future companies can take another quantum step forward by combining Lean Six Sigma with advanced Root Cause Analysis (RCA). The value of taking this natural progression on the way to achieving new levels of organizational excellence is presented.

Jan 1, 2011

By C. Strachan

This paper presents an evaluation of tailings dam incidents from the 1994 USCOLD Tailings Dam Committee report. Comparisons are also made with water storage dam incidents from USCOLD reports and recent tailings dam incidents. The evaluation results show that tailings dam incidents are due to a number of factors including overtopping, static and seismic instability, seepage and internal erosion, and foundation conditions, and that no particular type of tailings dam or operational condition is more susceptible to incidents. In addition, the results confirm that tailings dams should be located, designed, operated, and reclaimed with a thorough knowledge of site conditions, mill operation, site monitoring, and tailings characteristics.

Jan 1, 1999

By J. W. Hawkins, K. B. C. Brady, M. W. Smith

The Pennsylvania Department of Environmental Protection (PaDEP) has been issuing surface mining permits since 1984 that authorize remining in areas that will affect preexisting pollutional discharges. These permits require the mine operator to employ best management practices to reduce pollution loading from abandoned mine discharges. A total of 110 completed mining operations with 233 discharges were evaluated to determine the impact to water quality. Overall, acid loading from these discharges was reduced by 7,200 kg (15,900 lbs) per day or 61%. Metals loadings were also reduced. For acidity, 49% of discharges improved or were eliminated, 52% showed no significant change, and fewer than 1% got worse. Loading reductions resulted from a combination of reduced concentrations and lower flows.

Jan 1, 2002