Search Documents

By Verya Nasri, Heather M. Ivory, Kevin Clarke, Eric Cole

Development of the New York City Water Supply System The New York City water supply system serves a population of almost nine million, including residents in neighboring counties. Peak day demands on the system are currently running at about 70 m3/sec (about 1,600 mgd), which is significantly lower than in the 1990s. This trend of reducing demands over the past 25 years, which has been experienced in other major urban centers in the US, is mainly the result of conservation measures and increased cost consciousness on the part of water users. In the long term, demands are expected to once again follow an increasing trend with population growth, so that by the end of the planning horizon of these studies, the year2045, the peak day demand is expected to increase to about 85 m3/sec (2,000 mgd).The system is served largely by surface water sources, regulated by a system of 19reservoirs and three controlled lakes, which are connected to the City by a series of aqueducts, the longest of which is about 87 km (54 miles). The total storage in the sys-tem amounts to about 560 billion gallons, providing a system firm yield of about1300 mgd. The Delaware system provides about 50% of the City’s water, the Catskill about 40%, with the remaining 10% provided by the Croton. The system as a whole, which is shown on Figure 1, has been built up over the past 150 years, and is truly a marvel of engineering. The Catskill and Delaware aqueducts both discharge into Kensico Reservoir, which is a daily balancing reservoir located in Westchester County about 24 km(15 miles) north of the New York City line. The two aqueducts extend south for a further 14 miles to combine again at Hillview Reservoir in the Bronx, which provides hourly balancing storage for New York City system. The Croton aqueduct runs nearby as shown on Figure 2, but does not connect into the two reservoirs. From Hillview Reservoir the water is supplied to the city via three main distribution tunnels, known as City Tunnels 1, 2, and 3. City Tunnel No.1 was developed in the 1920s as part of the Catskill system. City Tunnel No. 2 followed in the 1960s as part of the Delaware system. City Tunnel No. 3 (CT3) is partly under construction and partly in operation, and is being implemented to permit the other distribution tunnels to be taken out of operation for the first time for inspection and maintenance. Presently CT3 is supplied with water from Hillview Reservoir via a large underground valve chamber, the Van

Jan 1, 2007

By Rolando Gonzalez

Mexico’s role in the world economic community continues to grow. And it is important that the country makes use of its natural wealth, including its large underground deposits of minerals and metals. With that in mind, Industrias Peñoles S.A. de C.V.(Peñoles), a mining, smelting and refining company, began mining lead, zinc and other metals from the Francisco I. Madero Project (FIM). The mine is located about 600 km (370 miles) northwest of Mexico City in the state of Zacatecas. Peñoles plans to remove about 3 Mt/a (3.3 million stpy) of ore from FIM. To achieve this goal, the company needs to optimize its processing, to maximize the amount of metal it extracts through FIM’s large flotation lead-zinc concentrator. To ensure high productivity, Peñoles and its contract engineering firm, M3 Engineering and Technology, of Tucson, AZ, have implemented anore processing system.

Jan 1, 2003

"The National Mining Hall of Fame and Museum (NMHF&M) announced the 2015 National Mining Hall of Fame inductees and the 2015 Prazen Award winner. This year’s inductees, selected by the National Mining Hall of Fame’s Board of Governors, represent the technology, management, mineral policy, education and health and safety aspects of the mining industry. They envelope a diverse cross section of the mining industry and were selected for being visionaries, leaders, educators and ambassadors.In 2015, Frank F. Aplan, T S Ary, Ralph E. Bailey, John Campbell Greenway and Edward Steidle will join 227 other mining industry honorees when formally inducted into the National Mining Hall of Fame. The Prazen Living Legend of Mining Award will go to the Powell River Project Research and Education Center, a partnership of Virginia Polytechnic Institute and State University (Virginia Tech) and the Appalachian coal mining industry.The 2015 annual induction banquet and ceremony will be the 28th such event and will be held this year in Pittsburgh, PA, on Oct. 23, 2015, in the Omni William Penn Hotel ballroom.2015 National Mining Hall of Fame inductees:Frank F. Aplan is among the most influential mineral processing leaders in both industry and academia. His studies of the processes involved in the preparation of coal and mineral ores are acknowledged worldwide for their broad applicability. An authority on flotation, Aplan is especially known for his studies of the wetting of solids and their control through the adsorption of surfactant films, and for his work on atomic defects on properties and behavior of solid-liquid interfaces."

Jan 1, 2015

By J. Kretschmann, O. Drusche, S. Krause

Mining companies are caught between the growing international relevance of ESG (Environmental, Social and Governance) investments and the need to secure their “social license to operate” by considering the needs of their stakeholders. In the search for sustainable business models, the concept of the circular economy (CE) is gaining momentum among practitioners and scholars, as it enables the creation of shared value and thus strengthens the trust of investors and stakeholder relationships. However, there is a lack of a sectorspecific CE framework providing guidance to decision-makers in evaluating promising activities. A gap, which this contribution aims to address.

Mar 2, 2022

By J. Geisler

When addressing Germany’s resource supplies, we need to distinguish between those domestically available and imported ones. Resource extraction ostensibly competes with the designation of protection areas. However, the parallel existence of wildlife and plant life, and operations in the areas used for resource extractions is continually underestimated. The European Commission has compiled guidance documents facilitating the extraction of resources from protected areas. With regard to resource productivity, the market appears to be the appropriate instrument for minimising resource consumption. Policy makers are now called upon to create a legal framework leading to a consensus accepted by society.

Jan 1, 2011

By B. Boberg

Annual requirements of uranium to fuel the 441 currently operating nuclear reactors in the world is 170 million pounds U3O8 (65,385 tonnes U). 2005 global production was 108 million pounds (41,595 t U), of which only 2.7 million pounds U3O8 (1,039 t U), was produced from US uranium deposits. US nuclear utilities represent 26% of the global nuclear capacity but only obtain 2.5% of their supply from US uranium mines. Since 2002 annual global production increased from 93 million pounds U3O8, a 15% increase and the US production increased from 2.3 million pounds to 2.7 million pounds, a 17% increase. Reasonably Assured Resources (RAR) of 12,332 million pounds U3O8 (4.7 million t U) are reported from a wide variety of countries and types of uranium deposits. This RAR suggests that there are significant global uranium resources potentially producible at a price of $50 per pound U3O8 ($130 per kg U). Table 1 shows the distribution of global uranium resources. This table, prepared from historic data maintained by the World Nuclear Association, does not include some areas of the world that are currently considered to contain significant resources of uranium such as Mongolia. Table 1 suggests that the United States contains the fourth largest uranium resource in the world with 890 million pounds U3O8, behind Australia, Kazakhstan and Canada in resources that are producible at a price of $50 per pound U3O8 ($130 per kg U). Within the US, the states that demonstrate the greatest amount of uranium resource are Wyoming, New Mexico, Texas and the Four Corners Area of Arizona, Colorado and Utah.

Jan 1, 2007

By C. G. Cunningham

The Marysvale volcanic field of west-central Utah contains large areas of argillically altered rocks (fig. 1) that, in turn, enclose smaller areas of fine-grained, medium-grade, replacement alunite deposits and coarsely crystalline, high-grade vein-type alunite deposits. The largest replacement alunite deposits are [ ] located peripheral to a 23-m.y.-old monzonite stock called the Central Intrusive (fig. 1). The deposits formed in near-surface, highly oxidizing environments at the tops of hydrothermal plumes that were spaced irregularly around the stock. The deposits are horizontally zoned from alunitic cores through kaolinitic to propylitic envelopes. Vertically, characteristic alteration minerals progress from a pyrite-propylitic alteration assemblage at the base, upward through alunitic, jarositic, and hematitic assemblages to a flooded silica cap as shown on figure 2. The silica caps are cut by hydrothermal explosion breccias. d34Sso4 values of + 11.5 to + 15.4 permil indicate that sulfur in the hydrothermal plume was derived from underlying Mesozoic evaporites. The sharp upward transition from pyrite- propylite to alunite probably marks the paleowater table, and the top of the flooded silica cap represents the paleoground surface. Basin-Range extensional tectonism began shortly after alteration, and buried the replacement alunite deposits in basins beneath sediments eroded from uplands. The deposits were only recently exhumed.

Jan 1, 2013

By Steve Kral

The domestic mining industry may be in the doldrums but there appears to be hope, at least from a regulatory standpoint. At least one US senator believes that the events of Sept. 11, 2001 made many citizens see the need for the country to become more self-reliant on its growing energy needs. Even before that tragic day, however, the Bush administration was making a strong push to open up more public land for energy and natural resource development.

Jan 1, 2002

By G. Budge

In the extractive industry the term ‘continuous improvement’ (CI) usually means procurement of the latest state of the art equipment. This is generally perceived as the only way to add further value to the supply chain, with the driving philosophy of increased tonnage to dilute operational costs. However, not all market places can facilitate this approach. RJB lives in a fiercely competitive market and has targeted the standard efficiency drivers of rationalisation and stock management with a vengeance; and also operate CMMS (Computer Maintenance Management System), RCM (Routine Condition Monitoring)and CBM (Condition Based Maintenance) methodologies. Ultimately though, these systems are only as good as the people who operate and manage them and to add further value without procurement, people must be re-introduced back into the operation. Through TPM (Total Productive Mining), that is what RJB have set out to do.

Jan 1, 2001

By Gary B. Glass

Seventeen percent of US coal production now comes from the 19 surface coal mines in the Powder River Basin of northeastern Wyoming. The Powder River Coalfield, which coincides with this topographic and structural basin, is unique to the conterminous US, in that it contains an estimated 934.4 Gt (1.03 trillion st) of in-place coal resources. At least 13.2 Gt (14.6 billion st) is a compliant, strippable reserve base. In 1993, an estimated 162 Mt (179 million st), or 98% of the coal mined in this Wyoming coalfield, came from the thick - average 30.5 m (100 ft) - subbituminous, Wyodak coalbed, or from the Anderson and Canyon coals in the one mine where the Wyodak is split into two separate coalbeds. The other 2.7 Mt (3 million st) of coal mined in the Powder River Basin in 1993 came from the School, Badger, Monarch and Deitz No. 3 coalbeds. In this "world class" coalfield, there are at least 13 other persistent, 3 to 15 m (10 to 50 ft) thick, coalbeds as well as the Big George and Lake De Smet coalbeds, which are each 61 m (200 ft) or more thick in places. None of these latter 13 coals are mined at this time.

Jan 1, 1994

By Emily Wortman-Wunder

As the 2013 president of the Society for Mining, Metallurgy and Exploration, Inc., I am pleased to present the 2013 issue of the Transactions of the Society for Mining, Metallurgy and Exploration, Vol. 334. The timely publication of professional papers that promote the advancement of scientific and technical knowledge is critical for enabling technology transfer. SME plays a key role in this process through its publications. Communication within the mining community is the key to a successful profession and society. This technology exchange continues a tradition that dates back to the 1871 meeting of 22 mining engineers in Wilkes-Barre, PA, that resulted in the founding of AIME; those individuals envisioned that these transaction volumes “would form a most valuable and greatly needed addition to our professional literature.” This volume fulfills that pledge. The 2013 Transactions contains 73 papers covering most every aspect of the mining life cycle and encompassing the diverse sectors of our industry including coal, industrial minerals, metals, health and safety and computational methods. It includes all 18 papers published in 2013 in the Technical Papers Section of Mining Engineering magazine (Vol. 65) and all 33 papers published in 2013 in Minerals & Metallurgical Processing (Vol. 30). Additionally, this volume contains 22 papers that are being published for the first time in this issue. The papers presented in this volume were written by some of the most distinguished professionals in the industry worldwide. Some of the many research highlights from 2013 include discussions of perennial issues, such as how to adequately prepare the next generation of mining engineering students for the workforce (Frimpong et al., pp. 44-52) and how to predict and prevent coal mine bursts and bumps (Pariseau, pp. 60-68), the highly anticipated February Rare Earths issue of Minerals & Metallurgical Processing, and papers analyzing electrical injuries in the U.S. Mining industry (Homce and Cawley, p. 367-375) the latest in assessing the safety and efficiency of operations. All 73 technical papers were peer-reviewed. The process of review and publication requires much hard work by authors, reviewers and our publications staff. As the 2013 president of SME and on behalf of all our members, I would like to extend our gratitude to all whose volunteer efforts contributed to the publication of this volume.

Jan 1, 2013

By M. A. Reyes, L. Yan

Heat and humidity buildup withn refuge alternatives (RAs) may expose occupants to physiological hazards such as heat stress. The Mine Safety and Health Administration (MSHA) regulations require RAs in underground coal mines to provide a lifesustaining environment for miners trapped underground when escape is impossible. RAs are required to sustain life for 96 h while maintaining an apparent temperature (AT) below 95 °F (35 °C). The National Institute for Occupational Safety and Health (NIOSH) tested a 10-person tent-type RA, a 23-person tent-type RA, and a 6-person metal-type RA in its underground coal mine facilities to investigate the thermal environment over a 96-h period. The test results showed that mine air and mine strata temperatures surrounding an RA occupied by simulated miners (SMs) increased over the 96-h test period. The test results suggest that RA manufacturers should consider this increase in temperatures when calculating and evaluating RA components during surface and laboratory tests. The findings can equip stakeholders with additional considerations for calculating the interior heat and humidity temperature profiles for occupied RAs not tested in situ.

By T. E. Bernard

Occupying a refuge alternative (RA) is an accepted practice in mine fires and explosions when escape is not feasible. MSHA has promulgated a final rule on refuge alternatives that includes a recognition that thermal environment is an important consideration. To this end, an environmental index was specified. The question remains about how to test a refuge shelter to demonstrate that it meets the final rule. The analysis followed five activities: A. Provide an estimate of heat generated by an individual refuge alternative occupant; B. Evaluate the Steadman Apparent Temperature criterion of 95°F; C. Discuss simulations based on body temperature or skin temperature limits; D. Suggest method of simulating human heat generation during refuge occupancy; and E. Suggest alternative methodologies/criteria for evaluating heat and humidity survivability inside a refuge alternative.

Feb 27, 2013

By R. Larry Grayson, Joel R. Warneke

The mining industry has searched for a message that will resonate with the public while focusing on the industry’s positive contributions to society. So far, environmental groups remain unconvinced and the public is still largely uninformed. In the authors’ opinion, a number of recent events and experiences have converged to help shape a more effective public communication on mining’s important role. This article presents a perspective on coal’s role in sustaining society by anchoring the message in a transparent way, including a material flow analysis, that links coal’s impacts across a range of social and environmental aspects. Past and continuing image problems In her 1994 paper, Nancy Bingham, with Caterpillar, outlined what the public thought about mining. Based on extensive interviews, the following results were found: • The public believed mining harms the environment. • The public believed mining harms people in nearby communities. • The public believed mining exploits workers. • The public believed mining has little personal benefit to the individual.

Jan 1, 2006

By J. C. Yingling

[New stochastic process models are developed to calculate the probability of various fill levels in section feeders as a function of vehicle interarrival times, payloads and feeder-discharge rates. These models may be utilized to establish the minimum feeder-discharge rate necessary to prevent a feeder, with a particular surge storage capacity, from constraining the section's production rate. In addition, it is shown how the output from these models may also be utilized to calculate the probability of various flow rates at junctions in the conveyor haulage network, enabling one to size gathering belts. The model provides a basis for optimizing, (in economic terms) capacity specifications for feeders and conveyor belts in the materials-handling system by considering tradeoffs in the size of the two types of units.]

Jan 1, 1997

By S. Schade, G. Möllemann, C. Niestroj

"Mining environments, whether open-pit or underground, pose difficult conditions for any sensor system. However, the ever-increasing need for automation requires the application and use of sensor systems in order to gather relevant information required for process automation. Ultra-Wideband radio (UWB) is a robust technology well-suited for underground applications. These applications include positioning and communication. This paper introduces UWB and presents results from measurement campaigns in harsh environments. Using filtering and sensor fusion precise and robust positioning can be achieved even in confinements of underground mining environments. INTRODUCTION Indoor positioning systems (IPS) are gaining ever more importance. Especially in light of ongoing efforts to reach the goals of what was coined as Industry 4.0 by the German government, the development of IPS is inevitable. According to a recent report about the “Global Indoor Location Market Outlook 2019” a growth from $ 597 million in 2014 to $ 3961.8 million by 2019 is expected [1]. Hence, there is also an economic incentive to pursue this topic. The mining industry is profiting from this development as well, since IPS are the basis for the automation of especially mobile mining equipment. Ideally, indoor positioning systems offer to position the equipment continuously and, what’s more, even in real-time [2]. Different approaches are available for IPS. The difference of these systems lie in terms of accuracy, cost, precision, technology, scalability, robustness and security. [3] At the Institute of Advanced Mining Technologies (AMT) of RWTH Aachen University, research suggests that one of the more auspicious approaches for IPS in the mining sector is the employment of ultra-wideband (UWB) radio technology. Because of this, there has been ongoing research into the best way to introduce UWB technology for the application in underground environments. The research started with an indoor positioning application, which only consisted of the UWB system. In the course of this, different algorithms were developed to enhance the system’s performance for the use in the mining industry. This led to the idea of sensor fusion in which the information of the UWB system are combined with infrastructure-independent technologies like inertial navigation systems (INS) and image-based technologies."

Jan 1, 2017

By Nan Hua

As a high production and high efficient mining method, top coal caving method is now widely used in China. However, as more extra-thick coal seams are mined, it becomes more and more difficult to make the top coal fully broken up, resulting in more and more top coals flowing into the gob, rather than onto the rear AFC at the working face as designed. This research is aimed to investigate the failure mechanisms of the extra-thick top coal caving mining method.

Jan 1, 2009

By D. Robert Weir, M. J. H. Ruscoe, R. M. Berezowsky, M. A. Clegg

The metallurgical processing involved in the produc-tion of the new Canadian one dollar coin is reviewed starting with the hydrometallurgical production of pure nickel powder, followed by the powder metallurgy process for the production of nickel strip and coinage blanks, and concluding with the Aureate bronze electroplating and heat treatment procedure. Coinage requirements are then reviewed with regard to economic, public acceptance, and service requirements. Finally the properties of Aureate nickel coinage are presented in the light of the many and varied coinage requirements, and it is concluded that the new Canadian dollar coin exceeds the requirements admirably.

Jan 1, 1990

By R. K. Jade

Although several studies in combining and bifurcating flows in two-way junctions and splits are reported, deviations persist in the estimated shock loss coefficients (SLCs). Due to their complex nature, more work has to be done to be able to correctly predict flow losses at these locations. In two-way splits, the flow at bifurcation is known to be characterized mainly by two recirculating zones in the downstream branches, whereas, in a junction one recirculating zone is observed immediately downstream of the main branch. The relative flow rate in the branches (quantity ratios) is treated as the only parameter defining the losses at these locations. However, the effect of wall roughness, if any, on SLCs becomes important for mine ventilation. This paper presents the critical determinants of shock losses at splits and junctions at varying quantity ratios. The flow at 90º split and junction was examined both experimentally and numerically for Reynolds number in the range of 1.0×104 to 1.6×105. With a well designed laboratory setup, using precision instruments, velocity and pressure measurements were carried out, by using two scales of wall roughness. 3D numerical simulations for these experiments were conducted by using ANSYS CFX modeling tool. CFD simulations yielded results that are reasonably close to experiments, providing high degree of satisfaction in numerically predicting losses across the splits and junctions. However, comparisons of these numerical simulation results with existing literature standards showed significant under-estimation of shock losses by the standard literature by as much as 50%. A clear rise in the magnitude of shock losses was noted in both the approaches, with increased wall roughness. Based on the current studies, predictor equations incorporating quantity ratios are developed for accurate estimation of shock losses. Further investigations on roughness are needed, before one is able to incorporate wall roughness into the prediction of SLC.

Jan 1, 2009

By Paul Sarnoff

The economics of precious metals -- depending upon who is involved --could be the economics of hope, of fear, indeed of profit and perhaps survival. For those investors seeking capital gains in a puzzling economy, precious metals involve the economics of hope. Those who are convinced that currency soon won't be worth the paper it's printed on turn to precious metals because of the economics of fear. Gold and silver have been a storehouse of wealth since biblical times. The economics of fear during the past 500 years on the Continent has caused almost every European family to make sure a private stockpile or hoard of gold, silver or coins is at hand in case the paper currency of their country undergoes the kind of disaster that came to the German Mark after World War I. Understandably, for mining companies involved in the production of precious metals, the elements of operations and management are directly concerned with the economics of profit -- and perhaps survival. To the American miner the price of precious metals in the marketplace is a matter of daily concern. After decades of selling silver to the US Government at 64.64 cents an ounce, producing silver mines suddenly became faced with prices breaking $5, $10 and $20 per ounce, and approaching $50 an ounce during the period 1978-1981. What should the miner expect one year in the future? Five years?

Jan 1, 1981