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The two candidates in the upcoming presidential election in the United States each say that they have their own solution to the nation?s energy problems - solutions that will increase the amount of energy available, lessen the nation?s dependence on foreign sources and reduce the amount of pollution released to the atmosphere. Democratic nominee Sen. Barack Obama and Republican candidate Sen. John McCain both advocate research funding for coal-to-liquids and clean coal technologies. McCain also supports increased oil and gas drilling offshore. And Obama has even made some noises in that direction, although his plan leans heavily on the increased use of renewable energy sources. The energy debate is not new to this election. Congress and whichever party is in the White House has for years been trying to craft a comprehensive energy policy. One difference in this latest debate is that the increased use of nuclear energy has gained more attention. Current President George W. Bush has said he favors the increased use of nuclear power as part of the nation?s energy package. And McCain said he supports the building of more nuclear power plants. Obama has not said much about that. The American public is also showing signs of changing its stance on nuclear energy. To be sure, images of Three Mile Island and Chernobyl are still alive in some minds. However, the American public has said it wants cheaper energy and they want it produced more cleanly. With nuclear, the nation can have both. In the United States, nuclear accounts for slightly less than 20 percent of the electrical power used (see interview with Gary Steele of Energy Fuels on page 27). Globally, that figure is about 15 percent. And there are several nations that derive better than half of their power from nuclear sources. Add to that the world?s increasing need for more energy and the future of nuclear is bright.

Jan 1, 2008

The support of the roof in coal mines remains a critical safety issue with 3 fatalities from roof falls in 2007 and 430 injuries from roof falls in 2006. A snapshot survey by the authors of room design and support details as well as unplanned falls of ground in the industry revealed some useful data concerning support use, seam details, fall dimensions, bolt lengths and spacing and the stand-up time.

Jan 1, 2009

The 21st Annual American Mining Hall of Fame Awards Banquet sponsored by the Mining Foundation of the Southwest will be held at the Sheraton Tucson Hotel in Tucson, AZ on Saturday, Dec. 6, 2003. This year’s inductee, guest of honor and featured speaker at the banquet will be Thomas J. O’Neil, recently retired president and chief operating officer of Cleveland Cliffs Mining. Prior to Cliffs, O’Neil spent 10 years with Cyprus Minerals. He was also professor and head of the Department of Mining and Geological Engineering at the University of Arizona. As representatives of mining heritage, the Hall of Fame will induct James Boyd and Thomas F. Walsh. Walsh discovered a rich gold telluride vein in Ouray, CO, which became the Camp Bird gold mine. Boyd was a former director of the U.S. Bureau of Mines, vice president of Kennecott Copper and later president of Copper Range.

Jan 1, 2003

By W. D. Monaghan

Flame cutting and welding is one of the major causes of fires and explosions in underground U.S. coal mines. On May 20, 2006, a flame cutting operation at the Darby Mine No. 1 led to an explosion that resulted in five fatalities. On January 22, 2003, another explosion caused by flame cutting at the McElroy Mine resulted in three fatalities and three serious injuries. On June 22, 1999, a flame cutting and welding operation at the Loveridge Mine caused a fire that resulted in sealing of the mine for an extended period. Finally, on March 19, 1992, an explosion at the Blacksville No. 1 Mine that was caused by welding resulted in four fatalities. The National Institute for Occupational Safety and Health (NIOSH) conducted a study on fires and explosions in underground U.S. coal mines that were caused by flame cutting and welding operations to determine the root causes of these types of fires and explosions. The methodology included interviewing mining personnel who perform flame cutting or welding operations in underground U.S. coal mines and visiting mines to observe these operations, and MSHA reports of investigations and accidents statistics were analyzed. The results were used to identify and compare differences between flame cutting and welding practices and techniques in small and large mines, Eastern and Western mines, low seam and high seam mines, room and pillar and longwall mines, and between experienced miners and new miners. As a result of this study, best practices and interventions were developed to reduce the number of fires and explosions caused by flame cutting and welding. This paper provides a summary of this work. Disclaimer: The finding and conclusion in this report are those of the authors and do not necessarily represent the views of the National Institute for Occupation Safety and Health.

Jan 1, 2009

By Wayne Green

The Regional Municipality of York, located north of the City of Toronto in Ontario, Canada, has experienced unprecedented growth during the past decade, with new home construction averaging 15,000 units per year. This rate of growth is planned to continue well into the future with a projected growth of more than 500,000 new residents by 2031, combined with a tar-get of more than 300,000 new jobs to provide a sustainable economic base for the region. It should be noted that York region has been designated as one of the key growth centers by the province of Ontario, aimed in part to meet the housing and employment needs of Canada?s growing population. York Region is a mix of urban and rural areas and is one of the most desirable areas to live in Southern Ontario. York region offers an attractive lifestyle, with its nine municipalities and the amenities created by the many rivers, streams and protected greenbelt areas that encompass more than 69 per cent of the region?s area.

Jan 1, 2010

By Joseph J. Feiler

Fires in underground coal mines are persistent problems anywhere in the world that coal is mined. Coal fires pose safety and health hazards in the form of mine subsidence, loss of energy reserves, destruction of property and surface improvements, and air pollution. In 1995, the US Bureau of Mines (US-BM), in cooperation with the Colorado Division of Minerals and Geology (CDMG),entered into a contract with Goodson & Associates Inc. (GAI) to design and field test the effectiveness of a new foamed grout technology called ThermoCell. GAI is a Lakewood, CO geotechnical and mining reclamation engineering firm. The company developed ThermoCell to control and extinguish underground coal fires. The viability of the special grout and the technology of application were established during a full-scale field demonstration at the abandoned IHI Coal Mine fire, near Rifle, CO. Following acquisition of additional funding by CDMG in 1999, Goodson returned to the site in April to continue the grouting to fully extinguish the IHI fire.

Jan 1, 2000

By A. A. El-Midany

Traditionally, the choice amongst different upgrading techniques or in finding the optimum operating conditions for a given upgrading technology depends on whether one is looking at the grade or the recovery of the valuable mineral in the concentrate. In fact, the conclusions are not usually the same. This is because the best technique or optimum operating conditions for the highest grade are not the same as the conditions to achieve the maxi-mum recovery. Therefore, a unique measure that takes into consideration both grade and recovery is urgently needed. Finding such a measure is the objective of this paper. A proposed measure provides a selectivity index in the range of 0 to 1, where 0 is no selectivity and 1 is ideal selectivity. The index can be obtained by plotting the so-called Fuerstenau upgrading curve, which relates the recoveries of the components in products of separation and a running regression applying a one-parameter equation. The measure was applied to assess the selectivity of selective flocculation under different operating conditions when used as a sensitive upgrading technique for ultrafine ground ores. After applying the proposed selectivity measure in the case of the selective flocculation of ultrafine Egyptian iron ore without the addition of cations, it was found that the optimum conditions are pH 11, 1 kg/t sodium silicate and 0.4 kg/t potato starch with a selectivity index of 0.55. With the addition of cations, the optimum conditions were found to be pH 11, 1 kg/t sodium silicate and 2 kg/t potato starch with a selectivity index of 0.65. It should be noted that determining these optimum conditions using the traditional grade or recovery measures was highly ambiguous.

Jan 1, 2008

By P. Ashayer, J. Curran

Introduction Rockfalls occur when rocks or boulders detach from mountains or hills and tumble down. They can pose significant hazards to infrastructure such as highways, buildings, and mine open pits, and they sometimes result in personal injury or death. Prediction of rockfalls is a difficult task. Slopes that are at risk of rockfall have highly variable geometries. The location, mass, and shape of the rocks that might dislodge and fall are uncertain. Moreover, the materials that make up a slope can vary considerably from one section to another. Furthermore, the relevant material properties are usually not well known. Performing probabilistic simulations of rockfalls, combined with proper statistical analyses, has proven to be an effective and acceptable method for dealing with these difficulties [1, 2, 3]. The movements of a falling rock can be classified as freefall, bouncing, sliding, toppling, or rolling. The falling trajectory is controlled mainly by the geometry of the slope, the block shape, and the energy dissipated at each contact of the block with the slope. A rockfall model is evaluated based on its ability to efficiently predict the velocity, frequency, height of bounce, and run-out distance of falling rocks. With this information, the engineer can design remedial measures such as restraining nets and ditches. Most of the existing rockfall simulators are based on particle models that consider the falling rock as an infinitesimal particle with a mass, called the lumped mass or stereomechanical models [1, 2, 3, 4]. Other models involve hybrid methods relying on simplified assumptions. The most common hybrid methods are based on contact searching for the movement of a dimensionless object and incorporate some aspects of rigid body impact for bouncing [5, 6, 7]. There are also some rigid body models in the literature that employ simplified versions of rigid body models [8, 9]. This study applies a more sophisticated rigid body theory based on rigid body impact mechanics (RBIM), which was developed by Stronge [10, 11, 12]. The new theory captures all modes of rigid body movement. Due to the importance of the rock geometry, single impacts of ellipsoidal and prismatic rocks with rectangular cross sections are investigated. The effect of rock slenderness on rebound velocities and energies is also investigated for ellipsoidal rocks. The correspondence between the model parameters and the data from the rockfall literature data will be discussed.

Jan 1, 2007

By L. Gertsch, R. Gertsch

Mechanical mining is steadily gaining usage in the mining industry. A variety of machines currently finds employment: tunnel boring machines, roadheaders, continuous miners, surface miners, and augers. These machines have advantages compared to drill and blast mining methods, including increased safety, lower cost, uniform muck size, and accurately sized openings. A century of experience with mechanical methods has already paid dividends to the coal industry. Current trends guarantee eventual development of true general-purpose hardrock mechanical mining machines. Mechanical miners will become integrated mining systems and will determine the design of mines, when several significant challenges have been met.

Jan 1, 2001

By M. Schafer

The 20 foot diameter cast-in-place tunnel lining for Phase 3 of the Mill Creek Tunnel (MCT-3) has been completed. This paper will summarize aspects of liner design and address the construction approach in placing the liner in areas of tunnel that experienced crown overbreak. Tunnel lining production rates, installation procedures and form buoyancies experienced during concrete placement will also be presented.

Jan 1, 2008

By Richard A. Bideaux

With both unit costs per meter and average depth of drilling constantly increasing, there is a strong incentive to maximize the information acquired from drill holes, and then to make this information accessible to the geological staff. The larger the drilling project, the more advantageous computerization of data is over manual methods. The conversion to computer-readable form and the verification of large amounts of drill-hole data can be a substantial data processing task, but once accomplished, the benefits in increased accuracy and speed of interpretation will compensate for the time and effort spent in the work. For an exploration project progressing towards a preliminary feasibility study, about half of both the time and costs for all computer work of the entire feasibility study are devoted to drill-hole data base organization, and maintenance. Once drill-hole results are quantified and verified to be correct, they are immediately accessible and are not subject to further transcription or reinterpretation of errors. To obtain maximum benefits from computer utilization in this area, the drill-hole data base should be set up along with availability of the first data. For some companies, this may initially comprise a large number of purely speculative drill holes on a spacing of perhaps 1 or 2 km. Although few of these drill holes may encounter economic material, thought should be given, at this time, to the variables which will be logged when such material is found. In this way, it should be possible to set up a consistent format into which all future drill-hole information will readily be accommodated. This format may even be carried over into the data base requirements for an operating property.

Jan 1, 1979

By Mahiyar Nasarwanji, Jonathan K. Hrica, Jonisha P. Pollard, Lydia M. Kocher, Brianna M. Eiter

Within the metal/nonmetal mining sector, fall-related incidents account for a large proportion of fatal and non-fatal injuries. However, the events and contributing factors leading up to these incidents have not been fully investigated. To help provide a clearer picture of these factors, an analysis of imminent danger orders issued by the Mine Safety and Health Administration (MSHA) between 2010 and 2017 at both surface and underground metal/nonmetal mine sites revealed that most orders are associated with fall risks. Of these cases, 84% involved the workers not using fall protection, fall protection not being provided, or the improper use of fall protection. Fall risks for workers most frequently occurred when standing on mobile equipment, performing maintenance and repairs on plant equipment, or working near highwalls. In most cases, a single, basic, corrective action (e.g., using fall protection) would have allowed workers to perform the task safely. Overall, these findings suggest that a systematic approach is needed to identify, eliminate, and prevent imminent danger situations. Furthermore, to protect mineworkers from falls from height, frequently performed tasks requiring fall protection should be redesigned to eliminate the reliance on personal fall protection.

By Kenneth J. Hartman

Introduction The term kaolin is derived from kauling, a Chinese word meaning high ridge. This was the name of a hill in China where kaolin was first mined several hundred years ago (Murray, 1976). Other common names used for kaolin include clay and China Clay. Clay technically has a broader meaning and could refer to bentonite and ball clay as well as kaolin. China clay, as a descriptive term, apparently results from kaolin's origin. But it could also be due to a significant historical use in ceramic applications. The terms kaolin and clay will be used interchangeably in this analysis because of the common practice of using these terms in the paper industry. Major reasons for kaolin's wide-spread industrial usages center on kaolinite's physical features of good color, low viscosity, and inertness. Kaolin is described as a hydrous aluminum silicate with an approximate composition of 2H2O • A12O3 . 2SiO2. A new version of the product is calcined clay with modified hydration content. It is gaining widespread use. Components of any particular kaolin, in addition to alumina and silica, are viewed as impurities. The more values deposits and, hence, higher priced kaolin products are those of the highest purity. Kaolin is the most widely used mineral in paper manufacturing throughout the world. Key production centers are located in England and the US. Most of the Tatter's production is located in Georgia. The key markets for Georgia kaolin are paper markets - both paper coating and paper filling. These paper markets extend throughout the world, not just to domestic markets. In fact, export markets are second in size only to domestic paper markets for Georgia's producers of kaolin. Just as the paper markets are important for kaolin producers, kaolin is an important raw material for papermakers. Compared to the other three major pigments - titanium dioxide, calcium carbonate, and talc - kaolin's 1984 tonnage for papermaking represented 85% of the total. Even though titanium dioxide's unit value is much higher, kaolin's estimated total 1984 value still represented 51% of total dollars spent by papermakers for the four pigments. Kaolin grades- are briefly defined using particle size and brightness as principal means of classification. Likewise, grades of papers using kaolin are defined using the American Paper Institute's guidelines. From these definitions, associated kaolin grades used in particular grades of paper are reviewed. Special emphasis is placed on how qualities desired in certain papers are achieved through the use of specialized kaolin grades. World kaolin production World production statistics (Coope, 1979; Table 1) demonstrate that kaolin is produced in many areas of the world. About 60% of production is centered in the US and England (Fig. 1). Deleting Eastern Europe's produc-

Jan 4, 1987

By Thomas J. DeMull

Development of the Batu Hijau copper project was completed in the fourth quarter of 1999 with the formal handover and start-up of ore processing facilities. The project began in August 1996 when the owner, PT Newmont Nusa Tenggara (PTNNT), awarded an engineering, procurement and construction (EPC)contract to Fluor Daniel (FD) for the development of the project. This included a copper concentrator, port, power plant, town site and infrastructure. PTNNT managed the development of the mine and the procurement of the mine equipment. In 1996, Batu Hijau was the largest mining project ever undertaken. Developing the Batu Hijau Mine was complex. It involved the work of thousands of people in all parts of the world to plan, engineer, procure, fabricate and manufacture equipment, supply and deliver materials and equipment, and build the plant.

Jan 1, 2002

By John E. Newby

The Brightwater Conveyance System consists of four tunnel segments in three tunnel con-tracts, comprising over 21,760 m (71,400 ft) of pressurized face tunneling in complex glacial and non-glacial soft ground conditions with a large proportion 60 m (197 ft) or more below the ground surface with up to 7 bars groundwater head. This resulted in unique technical challenges for establishing geotechnical baseline values. The process used to develop these baseline values and specifications with regard to the level of risk that the owner, King County, was willing to accept is described in this paper.

Jan 1, 2008

By K. M. Stone, N. J. G. Masson, A. C. Woollett

The Jabali zinc deposit, in Yemen, contains at least 9.4 Mt at a grade of 10.7% zinc, 2.2% lead and 77g/t silver. The zinc occurs as smithsonite with minor hydrozincite. The Jabali ore does not produce a zinc concentrate of sufficient grade to be acceptable to conventional smelter/refineries, and it has been necessary to formulate a less conventional development plan. This involves the construction of a mine and concentrator at Jabali and a metal production facility using a new flowsheet designed specifically for the treatment of oxide material, at Yanbu, in Saudi Arabia. In order to give the facility the necessary economies of scale, the Jabali concentrate will be supplemented by feed from other deposits, this may be either oxide or sulphide material. The paper outlines the geology and proposed mining and treatment operations at Jabali, the flowsheet for Yanbu and presents preliminary costs for both operations

Jan 1, 2002

By J. D. Morgan

The US economy continued to grow steadily in 1988, reaching an annual rate of $5 trillion in the last quarter (US trillion = 1012). The value of domestically processed mineral-based materi¬als rose 20% to $300 billion (US billion 109). The value of metals produced from US ores rose 40% to more than $10 billion, industrial minerals rose 6%' to $20 billion, and recycled scrap more than doubled to $10 billion. Increasing economic activity stimulated metal prices. Yearly lows and highs were 95 cents and $1.68 for copper, 52 cents, and $1.30 for aluminum, 34 cents and 42 cents for lead, and 43 cents and 75 cents for zinc. A number of mining and metal companies experienced significantly increased profitability. Consumer demand strongly affects mining because the US economy is relatively saturated with long-lived products. Consumer, mortgage, and Federal debt continued to rise. About 246 million US citizens already possess 170 million licensed motor vehicles and 100 million dwelling units. New car production remained at the 1987 level of 7.1 million units. Truck and bus production, however, rose 7% to 4.1 million units. New housing starts fell 7% to 1.5 million units. Imports supplied a significant proportion of total US consumption of several important mineral materials. By year-end, imports of crude and refined petroleum exceeded domestic crude oil production. Such imports cost $42 billion. Imports of nonfuel mineral-based materials were valued at $44 billion and exports at $35 billion. The US and Canada-the world's two largest trading partners-consummated a historic free trade agreement. In February, President Reagan transferred responsibility for stockpiling strategic and critical materials to the Secretary of Defense. And, in July, the GSA group that bought, stored, rotated, and sold stockpiled materials was transferred to the Defense Department's Defense Logistics Agency. Concern about apartheid in South Africa continued, resulting in increasing attention to chromium, manganese, platinum-group metals, cobalt, vanadium, and gold. The Defense Production Act, authorizing priorities and allocations, supply expansions, voluntary agreements, and the National Defense Executive Reserve, was amended to include provisions for averting harm to national security from foreign takeovers. The DPAct, in effect through September 1989, is now up for further extension. Under the Act, the US Bureau of Mines maintains the Emergency Minerals Administration. During the year, consultations were held with Canada to strengthen the North American Defense Industrial Base. Coal production, 60% from open pits, rose 5% to 870 Mt (960 million st). Nearly four-fifths was burned to generate 57% of US electricity. Exports included 56 Mt (62 million st) of metallur- gical coal and 29 Mt (32 million st) of steam coal, with a total value of $4 billion. Domestic petroleum produc¬tion fell 2% to 574 hm3 (3.6 billion bbl). Uranium mining, including recovery from phosphates, was unchanged at 5.9 kt (6500 st). Nonfuel minerals Major metals Raw steel production-a major con¬sumer of many minerals-rose 14% to 92 Mt (102 million st). Domestic iron ore production rose 25% to 59 Mt (65 million st), about 96% pelletized. Net imports rose 37% to 16 Mt (18 million st). Raw steelmaking capacity of 102 Mt (112 million st) was unchanged. Voluntary Restraint Agreements with 21 steel exporting nations limited im¬port penetration to about 20% of the domestic market. Domestic producers of bulk ferroal¬loys of chromium, manganese, and sili¬con operated at about 75% of capacity. The US mined no manganese or chro-

Jan 1, 1989

By Don Phelps, Dean Brox, Peter Procter, Andy Saltis, Tom Morrison, Jeff Pringle

The Greater Vancouver Water District is currently constructing the Seymour-Capilano Water Filtration Project to enhance the quality of drinking water in the Vancouver metropolitan area. The Seymour-Capilano Water Filtration Project comprises the 1,800 million litres per day Seymour-Capilano Filtration Plant, the 1,080million litres per day Capilano Pumping Station, twin tunnels with associated shafts, and the Capilano Energy Recovery Facility. The twin tunnels will convey raw water under pressure from the Capilano Reservoir to the Seymour Filtration Plant and return treated (filtered) water for distribution. The Twin Tunnels component of the project comprises twin, 3.7 m diameter, 7.2 km TBM bored tunnels, the 180 m deep Seymour Shaft as the main launch shaft, and two 4 m diameter, 268 m deep raise bore exit shafts at Capilano. The Twin Tunnels have been planned as predominantly unlined tunnels sited at depth entirely within granitic bedrock and cross under two major buried glacial valleys of breadths in excess of 1500 metres that are filled with glacial sediments to depths up to 200 metres. The maximum overburden along the tunnel alignment is approximately 400 metres. Comprehensive site investigations and studies were completed during the detailed design stage of the project. The construction of the twin tunnels started in the fall of 2004 and is planned to be completed by mid-2008.

Jan 1, 2005

By J. Kern, M. Cain, T. Torries

Until recently, the generation of electricity was regulated in all states and the value of generation assets in a regulatory environment for ad valorem taxation were based largely on the book value of the plant plus the rate of return on capital allowed by the state regulatory agency. This method of appraising utility generation assets is inappropriate in a competitive environment because past capital expenditures are not relevant in a competitive environment. However, it is not clear what valuation methods are appropriate after restructuring. This paper identifies key problems and advantages of other appraisal methodologies and makes comments on various valuation and taxation methods.

Jan 1, 2001

By John Marsden, Mike Botz

A variety of modeling techniques can be utilized to forecast metal production at heap leaching operations. These approaches reflect a wide range of complexity, flexibility, time to implement, cost, and accuracy. For many operators, a spreadsheet-based modeling technique is attractive since the calculations are directly accessible, models can often be developed by site staff, and the results are generally easy to extract and interpret. The authors have developed a spreadsheet-based modeling technique that provides a high degree of flexibility, while still considering detailed operating information for ore properties, leach kinetics, scaleup factors, lift height, and in-heap metal inventories. The technique involves establishing kinetic leach curves for each ore type to characterize metal extractions, followed by application of separate metal recovery curves to define the rate at which leached metals exit the heap in pregnant solution, taking into account delays due to the in-heap solution inventory. At any point in time, the difference between total metal extracted and total metal recovered is equal to the in-heap inventory of the leached metal. This modeling technique is particularly useful for larger multi-lift heaps where delays in metal recovery are appreciable due to in-heap solution holdup. The technique is also applicable to sites with multiple heaps, leach cycles, and/or metal recovery plants (e.g., carbon columns for gold; solvent extraction for copper). This paper describes the modeling technique, including input data required and methods for defining kinetic leach curves and metal recovery curves. The technique is compared against an alternative spreadsheet technique using a simplified in-heap solution inventory calculation to forecast metal production, which has proven to be effective at a number of sites.

Sep 3, 2019