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By R. A. Hevia

Florida Power and Light is the fifth largest investor-owned electric utility in the country. It has a service territory that covers 35 counties, or 28,000 square miles, 2.5 million customers, and serves 5.6 million people. The total installed capacity is 13,470 MW, generated by four nuclear units, 36 oil and/or gas fired units, and 48 gas turbine units. Traditionally, FPL has been an oil-based utility. In 1979, this dependency on oil became obvious when 42 million barrels of oil were burned during the year. At that time, it was also projected that, based on the current estimates of customer growth and available generation capacity through 1990, FPL's residual fuel oil consumption would increase from the 1979 level of 42 million barrels (6.7 million m3) per year to approximately 55 million barrels (8.7 million m3) per year by the mid-1990's. Concern over this was further aggravated by the fact that it was difficult to estimate both the price and quantity of fuel oil that would be available over the next decade since changes in the world market, decisions by oil producers and refiners, and international political developments would all affect the availability of oil. Also, at that time, the price of residual fuel oil had increased drastically, and there was no reason to think that these prices would soon stabilize. Thus, oil back-out became a primary objective of FPL and since then, FPL has been actively investigating ways to decrease fuel oil consumption.

Jan 1, 1985

By K. Hanumantha Rao, K. S. E. Forssberg, H. R. Manouchehri

The responses of calcite, feldspar and quartz minerals in a laboratory free-fall electrostatic separator after tribocharging with stainless steel, PVC and copper plates were investigated. The effects of H3BO3 and BaC12 chemical pretreatment on the electrical properties of the above minerals were examined. The changes in the electrical properties are discussed along with the determined charge, dielectric constant and electrical conductivity of the mineral samples. The electrical properties of the minerals and their responses to the electrical field during separation after tribocharging and chemical pretreatment are explored relative to the electrical behavior of the minerals.

Jan 1, 2000

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

"Underground refuge alternatives require an air source to supply breathable air to the occupants. This requires pressure relief valves to prevent unsafe pressures from building up within the refuge alternative. The U.S. Mine Safety and Health Administration (MSHA) mandates that pressure relief valves prevent pressure from exceeding 1.25 kPa (0.18 psi), or as specified by the manufacturer, above mine atmospheric pressure when a fan or compressor is used for the air supply. The U.S. National Institute for Occupational Safety and Health (NIOSH) tested a variety of pressure relief valves using an instrumented test fixture consisting of data acquisition equipment, a centrifugal blower, ductwork and various sensors to determine if the subject pressure relief valves meet the MSHA requirement. Relief pressures and flow characteristics, including opening pressure and flow rate, were measured for five different pressure relief valves under a variety of conditions. The subject pressure relief valves included two off-theshelf modified check valves, two check valves used in MSHA-approved built-in-place refuge alternatives, and a commercially available valve that was designed for a steel refuge alternative and is currently being used in some built-in-place refuge alternatives. The test results showed relief pressures ranging from 0.20 to 1.53 kPa (0.03 to 0.22 psi) and flow rates up to 19.3 m3/ min (683 scfm). As tested, some of the pressure relief valves did not meet the 1.25 kPa (0.18 psi) relief specification.IntroductionThe Mine Improvement and New Emergency Response Act of 2006 (MINER Act) was enacted in the United States in the wake of three mine explosions/fires 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 (U.S. Mine Safety and Health Administration, MSHA, 2006). 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 for underground coal mines. This mandate culminated in the 2009 adoption of changes to Title 30 of the Code of Federal Regulations (30 CFR) mining health and safety regulations, requiring underground coal mines to provide mine emergency refuge alternatives and associated components, to provide a life-sustaining environment for persons trapped underground. Such refuge alternatives can be either self-contained mobile units or built-inplace facilities. The regulatory changes also include provisions establishing requirements for MSHA approval of refuge alternatives and their components, and among these provisions are numerous criteria for providing a safe breathable atmosphere under positive pressure within the refuge alternatives. One specific criterion for maintaining a safe refuge alternative atmosphere requires the inclusion of an air pressure relief valve that will activate at a maximum of 1.25 kPa (0.18 psi), or at a pressure above mine atmospheric pressure, in the refuge alternative, as specified by the manufacturer when the breathable air is supplied by a fan or compressor (MSHA, 2008)."

Jan 3, 2018

A coal mine located in southern West Virginia recently set a world record for daily low-seam coal production using a Cat automated longwall plow system. In a 24-hour period on April 10 and 11, 2014, the Pinnacle Mine longwall produced 32,411 t (35,724 st) from the Virginia Pocahontas No. 3 Seam, in a seam height of just 1.42 m (56 in.) along the 298-m (980-ft) longwall face. The Pinnacle Mine, located near the town of Pineville and owned by Cliffs Natural Resources Inc., an international mining and resource company, operates a Cat Gleithobel GH1600 Longwall Plow System. A previous record was set by this system at Pinnacle in August, 2012 when 29,423 t (32,430 st) were mined in a 24-hour period. The record was set by the same system, mining its second panel after a comprehensive rebuild was performed by Carter Machinery, the Cat Dealer in that area. The rebuild encompassed a complete rebuild of the headgate and tailgate armored face conveyor (AFC) drive, the headgate and tailgate special AFC pans, the stageloader drives and return end, the complete crusher and all gearboxes for the plow, AFC and stageloader. Carter acquired the rights to sales and aftermarket support associated with the former Bucyrus mining products, both surface and underground, in 2013. ?Supporting and rebuilding a longwall plow system was a new experience for the Carter service team,? said Chris Curfman, president of Caterpillar Global Mining Sales and Support Division. ?However, given the record production results attained by the rebuilt system at Pinnacle, it?s obvious that they are up to the challenge of supporting the underground product lines at the same high standards and quality level that they have been delivering for many years on the traditional Cat surface mining products.? Tom Bluth, president of Caterpillar Global Mining Products Division, said, ?Caterpillar congratulates the Pinnacle team for this great achievement. Without their efforts and dedication this record would not have been possible. To safely deliver that kind of output from such a thin seam is remarkable. We have been privileged to work alongside their team to demonstrate the capabilities of Cat longwall mining technology. ?

Newmont Mining Corp. has been producing gold from the Carlin Trend for more than 45 years. Naturally, the focus, scale and complexity of the operations have changed considerably during this time. Newmont discovered and developed the Carlin Main orebody that is located about 32 km (20 miles) north of Carlin, NV. The property was developed as a one-mine, one-gold mill treatment plant operation, which produced about 6.2 t/a (200,000 oz/year) of doré gold bars. The initial mine, mill and gold refining facilities were relatively small in comparison to today?s standards. The milling circuit used the Merrill-Crowe zinc precipitation process to recover dissolved gold and prepare a concentrated precious metal ?precipitate? to be melted into a doré bar for sale.

Jan 1, 2012

By Ruben Piqueras, Juan Luis Magro, Jorge Vázquez, Santiago Martínez, Xavier Manjarín

The Parallel Thimble Shoal Tunnel project involves the construction of a bored tunnel under Thimble Shoal Channel in Chesapeake Bay (VA), between two artificial islands and parallel to the existing tube tunnel, built in the sixties. It will be the first transportation tunnel constructed in the Mid-Atlantic region using a Tunnel Boring Machine (TBM), a 44-foot-diameter Earth Pressure Balance (EPB) named "Chessie," manufactured by Herrenknecht, and which was assembled at the CBBT's southernmost island, with extremely limited room, live adjacent traffic, and difficult access. "Chessie" was successfully launched in February 2023 and this paper describes this complex and challenging process.

Jun 23, 2024

By Georgene Renner, Chee Theng, William Gleason

"A walk through the exhibit hall or a glance at the technical programing that was offered at the 2019 SME Annual Conference & Expo and CMA 121st National Western Mining Conference in Denver, CO, Feb. 24-27 makes it evident that the mining industry is an innovative one that is on the cutting edge of technology. However, a glance at the nearly 6,700 attendees of the conference and it is also evident that while the industry is moving forward at a rapid pace in some areas, it is lagging behind in terms of diversity, both in gender and ethnicity.At Monday morning’s keynote session, Hannah Ubi, a millennial and a public speaker who joked that she is the proud owner of a sixth-place swimming trophy and a number of participation medals, addressed a full house that consisted of many men with gray hair or balding heads. The issue of an aging workforce that is rapidly being depleted by retirements is not a new one for the mining industry. In fact, it has been a concern for the industry for more than a decade. The central question has long been, “when the current senior-level people begin to retire, how do we replace them, and how do we fill the knowledge gap that is walking off into the sunset?” SME has been on the front lines in searching for solutions to the impending problem and, along with industry partners, has worked hard to develop programs that will address these issues. Among other efforts, the Society has developed a Ph.D. fellowship program to encourage people to remain in academia to teach the next generation and to help train the next generation to take over in the private sector.“The SME Foundation’s Ph.D. and Career Development Grant program is exceeding expectations at this point with two Ph.D. students graduating and taking a position in academia and two professors achieving tenure,” SME Executive Director Dave Kanagy said during the conference.The Society’s Minerals Education Coalition (MEC) has done its part to help educate future generations about the mining industry with initiatives like EngineerGirl, the Boy Scout Merit Badge and Move Mining, the Shark-Tank-style competition that was held on Monday with five finalists competing for the top prize (ME, April 2019, page 53)."

May 1, 2019

By James Humphrey

There is a natural resistance to change in any form. When it comes to implementing a game-changing technology like autonomous haulage on an operating mine site, the resistance can at times appear insurmountable. Whether based on real information or misguided preconceptions, it?s essential that we don?t underestimate the effort it will take to overcome this resistance, while clearly recognizing when it?s worth the effort. These realizations did not happen overnight for sites where autonomous haulage has been implemented. Nor did they happen overnight for manufacturers of autonomous mining equipment. Caterpillar, for example, began building toward autonomy more than 30 years ago and had a truck operating in the mid-1990s. Lessons learned during those early years led to the realization that there was much more to be learned ? not just about the machines themselves, but about the systems and knowledge that must be in place for a successful implementation. Working closely with customers, initiating real-life demonstrations on mine sites, having discussions with regulatory agencies and other stakeholders ? these and many other activities were necessary before autonomy could be fully and successfully launched. After decades of effort, Caterpillar?s first official commercial autonomous mine site went to work in 2011 in Farmington, NM.

By Antonio Tafra, Rene Dominguez, James Spenceley, Brady Hays

"Extracting one of the world’s most valuable natural resources — copper — hinges on the availability of the world’s most essential resource: fresh water. But try sourcing fresh water in one of the driest places on Earth, Chile’s Atacama Desert.BHP, majority owner of the Escondida copper mine in Chile’s Antofagasta region and Minera Escondida Limitada (MEL), operator of the mine, were looking for sustainable solutions to deliver desalinated water to the mine, while protecting the environment and complying with the local water authorityregulations.The mining giant chose Black & Veatch to solve this challenge.Solving a global miningchallengeMines use large quantities of water for mineral processing and metal recovery. Water supply, and not mineral ore, is often the major constraint to mining production and development of projects, especially in Chile. Mining operations must have a reliable water source that complies with local regulations, without adversely impacting the environment or affecting the water supply of nearby communities.Worldwide, mining companies and their owners, shareholders and regulators are placing new levels of focus on minimizing the impact of mines on the surrounding landscape and communities. Balancing the economic benefits and needs of mining operations with the potential freshwater impacts requires mines to pay serious heed to the environmental and social issues related to water. Today, mining companies are being proactive and are taking action to protect precious freshwater resources while seeking opportunities to reduce and mitigate their water impact.Delivering a desalination solutionBHP and MEL needed an efficient, technologically advanced seawater desalination plant, along with a conveyance system and infrastructure that would carry desalinated water more than 180 km (112 miles) from the ocean to the mine. Four pumping stations convey the water to a reservoir at the mine site, which is 3,200 m (10,500 ft) above sea level."

Jan 6, 2018

By Stewart W. Daniel

Competitive pressures involving product duality, uniformity and economics are increasing the interest in and accelerating' the adoption of automation by the cement industry. The demands of this industry on instrumentation and control manufacturers for more effective and reliable control of process variables is also increasing. The trend to replacing small grinding mills with a fewer number of larger mills is lowering the investment requirement per unit of capacity both for the mills and for their automation. Cement process control systems of today are more sophisticated than the equipment installed two or three years ago, not because the process itself is more complex but because todays demands require a higher degree of control action and accuracy. Because of increasing labor costs, an important objective of an automation program is a reduction in the process labor content. This can be realized by allowing the operator free time for other duties, by increasing the number of grinding circuits one operator can supervise and by removing to. a large extent the need for the operator to make process' adjustment decisions.

Jan 1, 1965

By J. A. Marts, R. C. Gilmore, S. Saki, J. F. Brune

El modelamiento de la dinámica de fluidos computacional (CFD por sus siglas en inglés) implica la creación de un dominio de cálculo llamado malla o rejilla para resolver las ecuaciones que definen la física del flujo de fluidos. Este proceso comprende a menudo emplear la mayor parte del tiempo en esfuerzos de modelamiento. En un proyecto patrocinado por el Instituto Nacional de Seguridad y Salud Ocupacional (NIOSH), los investigadores de la Escuela de Minas de Colorado utilizaron un enfoque innovador de mallas, el cual permite una fácil adaptación del modelo CFD para adaptarse a una variedad de geometrías de minado de tajos largos ventilados por canales (bleeders) y progresivamente sellados (referidos a menudo como bleederless en los Estados Unidos), con la porosidad y la permeabilidad de la cámara escalables en un amplio intervalo. En este trabajo se presenta la metodología del enfoque de enmallado y escalado junto con las recomendaciones para el uso de modelos CFD en aplicaciones de ventilación para las cámaras en tajos largos. La nueva técnica de enmallado se utilizó para evaluar la función de un retorno hacia atrás en una cámara progresivamente sellada y otra cámara ventilada por canales.

Jan 1, 2014

By S. W. Nicholson, L. G. Woodruff, K. J. Schulz, W. E. Cannon

The 1.1 Ga Midcontinent rift of North America has many similarities to the geology of the Voisey's Bay region in Labrador and the geology of the Noril'sk region in Siberia. These similarities include the hosting of large volumes of sulfur- undersaturated and trace-element-enriched basalt, having igneous centers characterized by crustal contamination, being characterized by metal depletions in some mafic units (an indication of prior sulfide segregation) and having known occurrences of Ni-Cu sulfide mineralization. These similarities along with new geophysical data and refined models for Ni-Cu sulfide deposits suggest that the Midcontinent rift probably contains undiscovered Cu-Ni [±] PGE sulfide deposits, some of which could be the size and grade of a Voisey's Bay or Noril'sk deposit. In particular, intrusions and related feeder systems that occur in northern Michigan and Wisconsin, as well as to the southwest along the rift margin, deserve serious examination.

Jan 1, 1999

By Thomas F. Clemens

This paper covers various changes in government regulations, taxation, and legislation for the past two plus years and the up- coming one. Part of the paper will discuss recent business conditions and how they have affected the cement and lime industry.

Jan 1, 1983

By O. A. Bascur

In recent years, metal-producing companies have increased their investment in automation and technological innovation, embracing new opportunities to enable transformational change. Transformation to a digital plant can fundamentally revolutionize how industrial complexes operate. The abundant and growing quantity of real-time data and events collected in the grinding and flotation circuits in a mineral processing plant can be used to solve operational issues and optimize plant performance. A grade recovery model is used to identify the best operating conditions in real time. The strategy for increasing the value of instrumentation in current plants is reviewed. An optimal Gaudin size distribution model provides augmented information from traditional sensors to find the optimal grind cut size to reduce metal losses in the flotation circuits. Sensors in flotation circuits enable an estimate of the recovery and determination of the optimal froth depth and aeration using an air hold up flotation model. A strategy of classifying data for on-line generation of insights to using operational intelligence tools is described. The implementation of a recovery/grind strategy with industrial examples in non-ferrous mineral processing is presented.

By George A. Roche

Since our firm was established by Mr. Price in 1937, we have followed an investment philosophy which is based on the belief that investment in growth stocks is the most assured way of achieving superior, long term investment accomplishment. There are many criteria that we use to select growth companies but the most important is a combination of superior management operating in an industry with above average growth potential. This growth stock approach is the cornerstone of our investment strategy for two of the three mutual funds sponsored by the Price organization and for our private clients. However, during the past 5 years we have seen inflation accelerate due to a variety of factors including the inability of our government to meet seemingly unlimited needs with limited revenue sources. While there might be temporary periods of price stability, we believe that inflation will still continue to be the investor's greatest problem in future years. Our conviction that inflation would increase combined with the acceleration of inflation in the late 1960s stimulated an intensive investment research effort, on our part, to identify those companies with strong natural resource bases -- who own or control large, secure, and low cost tangible assets. Over the longer term and in an environment of a depreciating dollar some of these firms should be able to develop and sell these assets at higher prices. While we still believe that investing in growth companies is a sound investment strategy to offset inflation, we also believe that certain natural resource companies will show well above average investment performance. In the newest Price mutual fund, The Rowe Price New Era Fund, we have, as a matter of policy, placed a large portion of the portfolio in natural resource companies.

Jan 1, 1972

By Dru Brown

More than 150 Mt (165 million st) of material crashed down at the Bingham Canyon Mine (Rio Tinto/Kennecott Utah Copper) near Salt Lake City, UT on April 10, 2013. The mine, one of the largest openpit mines in the world, ceased operations and evacuated personnel prior to the slide when it was discovered that material was moving at a rate of 5 cm/d (2 in./day). The slide destroyed the mine?s visitor?s center, buried several pieces of large mining equipment and severely hampered production. The Kennecott Utah Copper Corp. immediately began to assess the damage and look for options to reestablish operations. The highly unstable ground ? emphasized by another minor slide in September 2013 ? makes any cleanup efforts extremely dangerous. With terrain too dangerous for human operators, Kennecott was forced to look for alternatives that would help the company work on the treacherous slopes of the landslide while also keeping personnel safe.

Jan 1, 2014

By Kexin Cai, Isidro Rivera, Shawna Von Stockhausen, Maria Chastka, Kevin Huynh

The Newell Creek Dam Inlet/Outlet Replacement Project is located approximately 11 miles north of Santa Cruz, California along Highway 9 in the San Lorenzo Valley. This project will replace the existing inlet/outlet works at the Loch Lomond Reservoir by constructing a tunnel using conventional excavation methods while simultaneously drilling three intake shafts to intercept the tunnel from within the city’s water supply. This project will improve the system’s overall operational efficiency and performance, and provide a safe and reliable facility for the City of Santa Cruz’s drinking water supply. This paper discusses the overall project configuration, construction observations, and challenges during construction, including tunnel excavating through the marine sedimentary siltstone of the Monterey Formation, probing and pre-excavation grouting, and the tools utilized to manage the project.

Dec 1, 2022

By Carl P. Venzke

Mining lignite in the Gulf Coast often requires some interaction with shallow ground water system. Suggestions for determining ground water data and analysis requirements for regulatory compliance are given. Simple methods for estimating mine inflow seepage, ground water level declines, and changes in ground water chemistry, which may result from mining, are discussed. The mining of lignite often results in interaction with shallow ground water systems. An evaluation of the interaction is required as input to mine permitting and engineering. Your evaluation will proceed more smoothly and produce more meaningful results with some planning prior to performing your evaluation. The following are tips to consider in planning and carrying out a successful study.

Jan 1, 1982

By Winn B. Frank

Events of the mid-1970's have materially affected US coal production and transportation by railroad. Coal, as a replacement or substitute for petroleum fuels, has been hauled in significantly increased tonnages. Concurrent with the new demand, the railroad regulatory environment has undergone major changes, especially in "deregulation" activity. Those two events have produced considerable Litigation regarding coal rates. This paper discusses the factors involved with railroad rates and topics such as revenue adequacy, Ramsey Pricing, stand-alone cost, and differential pricing. In addition, an update on the western railroad merger situation and the implications for coal transportation are presented. The paper concludes with an evaluation of the current regulatory climate and future prospects.

Jan 1, 1983

By Ed Schodowski

Wireless technology is a hot topic for anyone involved in the design, operation, maintenance or upgrading of mines or mineral processing plants because wireless technologies overcome barriers that have prevented many useful data inputs. Wireless communications can contribute to worker safety, satisfy environmental concerns, support plant security, track human and physical assets, and improve equipment maintenance. The cost structure of wireless is compelling and users can realize savings ? up to 90 percent less installed cost than wired instruments ? since wireless technology eliminates the need for expenses associated with cabling, engineering, construction and documentation. Many applications previously considered too expensive have become economically feasible with wireless. Two examples are continuous monitoring of safety showers to notify operators when one has been activated, and monitoring effluents to ensure environmental regulations are being met. In many cases, wireless transmitters can be installed where wired devices were too expensive to justify, or were not feasible due to physical or technical barriers. Examples include monitoring temperature measurements inside a rotating reactor or monitoring process variables in a tough, corrosive environment too challenging for a wired solution. Wireless also gives operating personnel mobility with the ability to communicate from remote or hard-to-reach zones. According to a recent Venture Development Corp. survey covering radio frequency (RF) of microwave industrial monitoring and control products, these features are contributing to the expected nationwide growth rate for industrial wireless applications of 19 percent annually from 2007 to 2012 (Taylor, 2008). At the same time, mineral producers have many questions about wireless systems including their applicability, reliability and security in this industry. Just what can wireless do? Is it secure and reliable? Can these instruments stand up to the rigors of the industry? Can wire-less technology provide the flexibility needed for mining applications?

Jan 1, 2009