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By Steve Rogers

Nautilus Minerals was listed on the Toronto Stock Exchange in May 2006. The company now has major mining companies Anglo America (5.7%), Teck Cominco (7.2%) and Epion Holdings (22.4%) as significant shareholders, and has raised approximately $US346 million dollars to develop the world's first deep-water mine. The company is currently targeting high-grade copper and gold in seafloor massive sulphide mineralization, located near plate boundaries in back-arch basins of the Western Pacific. The first mine scheduled to be developed by the company is located in 1,600 meters of water at Solwara 1, in the relatively quite waters of the Bismarck Sea approximately 50 km from the port of Rabaul, within the Territorial Waters of Papua New Guinea. During 2006 and 2007 the company completed detailed environmental and geological studies, culminating in a number of world firsts, including the world?s first NI 43-101 compliant resource statement and environmental impact study for a seafloor massive sulphide system. Permitting is well advanced for the project, with initial production scheduled for late 2010, subject to timely grant of the permits. Extensive government and stakeholder liaison and engagement has been undertaken throughout the projects life, and is a core feature of Nautilus' desire to "do it right" in all aspects of this new industry.

Jan 1, 2008

By Kenneth R. Ware

I INTRODUCTION The Washington Metropolitan Area Transit Authorities (WMATA) rapid transit system (METRO), currently under construction, will have a total length of 98 miles. Forty-eight of these miles are underground and require either open cut excavations or tunnels. Despite stringent construction controls, it is inevitable that some ground settlement will occur adjacent to the deep open cut earth excavations and large diameter earth tunnels. It is therefore essential to underpin nearby important structures to prevent excessive differential settlements and Fig. 1 presents the METRO criteria for this underpinning. This paper describes the underpinning methods currently used on METRO and evaluates the effectiveness of each method. II DESCRIPTION OF SUBSURFACE STRATA The foundation materials in the Washington, D.C. area are extremely variable. Fig. 2 presents an idealized profile showing typical subsurface strata. The engineering properties of each stratum have been determined by extensive exploration and testing programs. Fill: Washington, D.C. fills consist of every variety of soil and rubble. They are not important to this study because no underpinning is founded on fill material. Terrace Deposits: Formed in outwash plains during the glacier period, these deposits are composed of random layers of either sand 1 The writings and opinions expressed herein are solely those of the author and do not necessarily reflect those of WMATA.

Jan 1, 1974

By N. Colvin, J. W. Gulyas

HISTORY The Surigao Nickel Refinery of Marinduque Mining and Industrial Corporation is located on Nonoc Island off the northwestern coast of Mindanao in the Philippines. Nonoc Island is part of the Surigao Mineral Reservation which had been identified as early as 1912. Initial interest in these deposits was due to their iron content, and their value as a nickel deposit was not seriously entertained until the late 1950's. The Philippine government undertook extensive test pitting and sampling programmes at that time and in the early sixties Marinduque became involved in helping to establish firmer ore reserves. Evaluations of the test pitting programme indicated reserves of 75,000,000 tonnes of ore averaging 1.22% Ni, 0.1% Co and 38.5% Fe. The Philippine government called for bids on the reservation in 1962 and Marinduque and Sherritt Gordon carried out some feasibility studies for the recovery of nickel from the deposit. However, it was not until 1968 that Marinduque was granted proper authority to exploit the Surigao deposits. Marinduque and Sherritt then entered into an agreement which allowed Marinduque to utilize a process developed by Sherritt for treating lateritic ores. During 1968, a 25 st/d pilot plant was erected in Fort Saskatchewan, Alberta for the purpose of modelling all process steps. A 10,000 tonne ore sample was sent from Nonoc as feed stock for the pilot plant.

Jan 1, 1979

By D. D. Lauriski

The Mining Division of Utah Power and Light Company is located in the coal fields of southeastern Utah -main office in Huntington, Utah. The Division will produce 6.5 million tons of low sulfur steam coal in 1988, making UP&L the largest underground mining operation west of the Mississippi. Coal is mined from three underground mines utilizing continuous miner and longwall mining methods. All coal produced by the Mining Division is utilized at UP&L's two largest steam-electric power plants, the Hunter and Huntington plants with a combined capability of 1,995,000 Kw. At UP&L we believe that to achieve success a company must have clearly defined goals which are understood, communicated and shared at each level of operation. We have also found from experience that a safe operation is generally an efficient and productive operation. As a Division, we have established a goal to achieve the safest, most efficient operation in the country. This is an ambitious goal. To achieve such a goal requires real commitment and a safety/training program capable of achieving needed results. The following is an overview of the program we have established at UP&L which has enabled us to reduce our accident frequency rate from over 40 in 1980 to 8.00 at present, as illustrated in Figure 1.

Jan 1, 1989

By D. L. Misterek, E. J. Slebir, G. W. Ring, M. A. Laird

INTRODUCTION In 1973, the Federal Highway Administration (FHWA) initiated a 10-year program of research on tunneling technology for future highways as a part of a larger Department of Transportation effort on tunnels. The objectives of the FHWA program are to: improve tunnel design technology, reduce costs, minimize adverse environmental impact due to construction, increase the rate of construction, and assure the maintenance of a safe and attractive tunnel environment. The program is divided into four research tasks designed to solve tunneling problems identified by the engineering and field offices of the FHWA. These tasks are as follows: 1. Cut-and-Cover Tunneling 2. Site Investigations 3. Ground Movements - Prediction and Control 4. Highway Environmental Criteria for Tunnels In order to provide input into Tasks 2 and 3, the FHWA is sponsoring an investigation and testing program by the U.S. Bureau of Reclamation to instrument and monitor two sites in the second bore of the Eisenhower Memorial Tunnel located on Interstate Highway 70 at Loveland Pass approximately 97 km (60 miles) west of Denver, Colorado. The tunnel will be approximately 14.0 m (46 ft) in diameter when excavated. The study is designed to generate data on: (1) changes in the state of stress, and movements during and after tunneling, (2) tunnel lining design requirements, (3) developing a

Jan 1, 1976

By F. J. Klingler, K. M. Swaffar, M. M. Rabbaig

The Detroit Water and Sewerage Department has undertaken a $1.2 billion effort to capture and treat combined sewage overflows from various outfalls along the Detroit and Rouge Rivers in Detroit, Michigan. This program is planned to include a 455,000 m3 (120 million gallon) storage and treatment tunnel which will capture overflows from 19 outfalls along the Rouge River. The tunnel is currently in the conceptual design phase, with the bid date planned for mid-year in 2001,and completion planned for August 2005. The total design and construction cost is currently estimated to be approximately $450 million. Current concepts are for the storage and transport tunnel will be 6.1 m (20feet) in finished diameter, with a total alignment length of approximately 12,200 m(40,000 feet). The main tunnel will extend through the Traverse and Antrim Shalerock formations, while approximately 5,500 m (18,000 feet) of various diameter connecting tunnel will extend through both rock and soft ground. The project will include a total of 10 drop shafts, 13 riser shafts, various connecting structures, and a 455,000 m3/day (20 mgd) pumping station. This paper will present a discussion of the design philosophy, subsurface conditions, the various planned components, and the expected design and construction considerations for the proposed Upper Rouge Combined Sewage Overflow Tunnel.

Jan 1, 1999

By Paul M. Keyser

Flotation columns continue to offer improved metallurgical and economic advantages over other flotation methods. Pilot testing at Ozark-Mahoning Co. in Rosiclare, IL led to installation of one 2.3-m-diam (7.5-ft-diam) column for zinc roughing and one 1.1-m-diam (3.5-ft-diam) column for zinc cleaning. This circuit replaced one stage of mechanical roughing-scavenging followed by two stages of cleaner flotation. General Column flotation continues to make inroads into applications traditionally dominated by mechanical flotation cells. For example, columns are becoming more visible as rougher flotation devices. At Royal Mountain King Mine in California, two 2.9-m-diam (9.5-ftdiam) columns are used for rougher flotation of carbon from a gold ore (Orlich et al., 1992). In addition, work performed at BRGM in France demonstrated the superiority of column flotation over mechanical flotation with respect to design of new plants (Morizot et al., 1991). The primary reasons for this acceptance of columns are a general improvement in design, scale-up and operation, as well as improvements in sparger design and performance. With these advances, the full benefits of column flotation can be realized. The benefits of properly designed, aerated and operated flotation columns include lower capital costs, reduced operating costs, fewer processing stages and improved metallurgical performance.

Jan 1, 1993

By George M. Potter

Precious gold and silver markets support substantial activity in the search for and development of improved and unconventional ore and tailing processing methods. The need for such methods 1s strengthened by consideration of increasingly low grade and refractory ores and old tailing reserves. As background for this review of new and unconventional precious metal processing, recent USBM data (1981) show annual world gold production of about 40.8 million troy ounces. In the U.S. about half the 2.8 million ounce consumption was used for jewelry and the arts, 39 percent for industry, and 8 percent for dental purposes. World silver production in 1981 was about 365 million ounces. Domestic usage the same year was about 117 million ounces. More than $ was used for photography and 30 percent for electrical and electronics. By process, about 1 percent of U.S. production of gold came from amalgamation, 66 percent from cyanidation, 31 percent from smelting ores and concentrates, and 2 percent from placers. As for silver, about 11 percent is from cyanidation and 89 percent from smelting ores and concentrates. Evidently the search for innovative and unconventional precious metal processes must include gravity concentration, froth flotation, hydrometallurgical, and electrometallurgical methods. Although smelting processes are equally important, they largely comprise nonferrous metal technology, and are not discussed here.

Jan 1, 1984

By Jeffrey P. Chanton

A specialized Pore-Fluid Array sampler (PFA) was designed to collect and store pore-fluids to monitor temporal changes of ions and gases in gas hydrate bearing sediments. We tested the hypothesis that pore-fluid chemistry records hydrate formation or decomposition events and reflects local seismic activity. The PFA is a seafloor probe that consists of an interchangeable instrument package that houses OsmoSamplers, long-term pore-fluid samplers; a specialized low-dead volume fluid coupler; and eight sample ports along a 10-meter sediment probe shaft. The PFA was deployed at Mississippi Canyon 118, a Gulf of Mexico hydrate site. A 160-day record was acquired from the overlying water (OLW) and 1.3 meters below seafloor (mbsf). Fluids were measured for dissolved chloride, sulfate, and methane concentrations and dissolved inorganic carbon and methane stable carbon and deuterium isotope ratios. Chloride and sulfate did not change significantly over time, suggesting the absence of gas hydrate formation or decomposition events. Over the temporal record, methane concentrations averaged 4 mM at 1.3 mbsf and was thermogenic in origin (d13C-CH4 = -32.4±3.4?). The timing of an anomalous 14 mM methane spike coincided with a nearby earthquake (Mw=5.8), consistent with the hypothesis that pore-fluid chemistry reflects seismic events. Keywords: Osmosampler, gas hydrate, methane, stable isotopes

Jan 1, 2008

By Jon Y. Kaneshiro, Gregory E. Korbin, Stephen J. Navin, Larry J. Stout

Sewage presently being discharged into the Tijuana River Valley pollutes the valley as well as the beaches in the South Bay of San Diego, making the beaches unusable nearly year round. The SBTO will convey flows down a 8.5 m (28 ft.) by 58 m (190 ft.) deep drop shaft, through a 3.35 m (11 ft.) by 5.8 km (3.6 mile) long tunnel, and up a 46 m by 2.7 m (150 ft. by 9 ft.) riser shaft connecting to a 1.5 km (0.95 mile) of seafloor pipeline and 1.2 km (0.76 mile) of diffusers on the ocean floor. The drop shaft will be sunk through 38 m (125 ft.) of saturated sands and gravels and 20 m (65 ft.) into the dense fine sands of the San Diego Formation. The tunnel liner has been designed as a five piece, single pass, gasketed, bolted, reinforced concrete liner designed to withstand an external head of 76 m (250 ft.) of water and internal operating head of up to 27 m (89 ft.) and to accommodate movement at the numerous fault crossings. The tunnel is contemplated to be driven with a state-of-the-art Earth Pressure Balance Machine (EPBM) or slurry shield machine through a wide range of conditions from clay to gravel with boulders.

Jan 1, 1995

By Patrick J. Doig

The Crosstown 7 Collector System, Contract C28G11, is part of the Milwaukee Metropolitan Sewerage District's Waste Pollution Abatement Program. The contract involves the construction of 1.6 km (1 mile) of 3 m (10 ft.) diameter tunnel in soft ground. The tunnel is 10 m (35 Ft.) below surface and passes through a variety of soils. The eastern leg of the tunnel along Bruce Street is mainly in till material, a stiff, relatively dry clay. The northern leg along 16th Street starts in till, and continues in estuarine deposits - moist sticky clay, with intrusions of alluvial sand and gravel. The contract specifications required that the tunnel be constructed either under compressed air or with an earth pressure balance tunnel boring machine. The S. A. Healy Co., the general contractor, chose the latter option. Additionally, a single pass, pre-cast concrete segmental liner was selected as the lining system. The mining machine was manufactured by Lovat Tunnel of Canada and the segments were made by the Sehulster Company of Milwaukee. The use of this combination of machine and lining is relatively new to the United States and this tunnel is the most extensive built to date with a gasketed, segmental single pass lining for transportation of fluids. This paper details the various aspects of the construction of the tunnel and associated shafts.

Jan 1, 1989

By John M. Wootten

The development of new coal markets is -t upon the ability to utilize coal in an environmentally acceptable and economically viable fashion. Foremost in the concerns about coal utilization is the impact its combustion has on air pollution. Concerns over environmental issues, such as acid rain, are currently one of the major impediments to the development of new coal markets. The Department of Energy and the Synthetic Fuels Corporation are addressing certain aspects of the development of new technologies for the utilization of coal. However, at the present time, there is a void in the new technology development process. That void is the step from proof- of-concept to commercial demonstration. Congress has established the Clean Coal Technology Fund at a level of $750 million to fill this void. The Department of Energy, in a solicitation of interest, received over 175 proposals for commercial demonstrations of clean coal technologies. A review of these solicitations indicates that $1.2 billion worth of research could be accomplished with a federal cost sharing of $425 million or 35 percent of the total. Industry has indicated, through this response, its willingness to invest its limited funds on projects it feels have the greatest potential for the clean use of coal. What must now occur is that Congress must appropriate the monies from the fund to initiate the commercialization of these clean coal techno1ogies.

Jan 1, 1986

The main goal of this paper is to present readers with recommendations for choosing coaxial cables appropriate for mining applications of Time Domain Ref 1 ectometry (TDR) to monitor rock mass movements. Prior to discussing the recommendations, mining applications are illustrated with examples and the operating principle of TDR is discussed briefly. Items that affect the result of the monitoring system performance include the coaxial cable selected, the grouting material used, and the installation procedure.

Jan 1, 1986

By T. W. Camm

One function of the U.S. Bureau of Mines is assessing potential economic impacts of federal land withdrawal policies. This often requires performing economic ana1ysls for an area with limited geologic information available. Input to the economic decision process relies heavily on estimates of mine and mill costs for the potential resources in the area being considered. A methodology for performing these cost estimates was needed to address this situation.

Jan 1, 1992

By Alan J. Michaels

The paper addresses the problem of the high costs of accidents ad how AMAX Inc. - a diversified natural resources company - has managed to control its losses through a tri-thrusted approach of: (1) management commitment, (2) methods of implementation that are tailored to each division or local unit, and (3) a reward system for outstanding performance. Specific attention is focused on the Corporate Loss Prevention Department's "10 Point Program for Loss Prevention Management".

Jan 1, 1981

By M. J. Mrugala

Typically the conventional pillar design methods consider the behavior of the pillar alone. In such analysis the contribution of the associated roof and pillar is not considered. The focus of this paper is a study of pillar behavior in the context of interaction between a different rock material sequence in the associated roof and floor. The finite difference element code FLAC (1)is used to perform modeling of pillar response to various stratigraphic sequences.

Jan 1, 2003

By J. Szarkowski

"INTRODUCTION The Butte district of Montana is well-known as one of the biggest historic producers of copper in the world. It is also a classic example of a porphyry Cu-Mo system that has been overprinted by zoned, polymetallic (Cu-Zn-Pb-Ag) lode mineralization. After copper, silver was the next most important metal mined from Butte, with over 700 million ounces of total Ag production between 1880 and the present day. Although many papers have been written on the mineralogy of the early porphyry Cu-Mo mineralization and the high-grade Cu-rich lodes in the center of the district, relatively little information exists on the mineralogy of silver in Butte. The purpose of this paper is to summarize past and present silver production trends for the district, and to combine previously published work with new research to examine the mineralogy of silver in the Butte mining district. BUTTE HISTORIC SILVER PRODUCTION According to a recent USGS compilation1, Butte is one of the most Ag-rich porphyry deposits in the world, both in terms of average Ag grade (8.6 g/ton) and total production + reserves (Fig. 1). It is also the 2nd biggest Ag-producing mining district in the U.S. (after the Couer d’Alene district, Idaho). Annual silver and copper production data for the Butte district, compiled from various sources2,3,4, are summarized in Figure 2. Peak production of Ag and Cu was in 1917. While Ag production gradually declined in the ensuing decades, Cu production remained strong until the years leading up to the closure of the Berkeley Pit in 1982. In 1984, mining of the nearby Continental Pit resumed under a different operator, and continues to the present day. The Continental mine produced an average of 35,000 metric tons Cu and 575,000 oz Ag per year between 1984 and 20044. These figures do not take into account a period of mine closure in 2001-2003 due to an unexpected hike in utility prices. The long-term decline in Ag/Cu ratio of ore mined in Butte (Figure 3) is due to several factors, including: 1) changes in metal prices; 2) a downwards decrease in Ag/Cu ratio of most of the lodes with depth below surface; and 3) a shift in mining methods from selective underground mining of high-grade veins to open-pit mining of the bulk rock."

Jan 1, 2016

By Gene E. McClelland, Dirk J. A. van Zyl

5.1 INTRODUCTION Heap leach cyanidation techniques possess considerable potential for exploitation of low-grade ores, small ore bodies, mine strip waste and tailing materials where fine grinding is not necessary for good extraction. For heap leaching to be successfu1, ore must exhibit certain characteristics, as previously discussed in Chapter 1. Primary among the necessary ore characteristics is that the ore must have good permeability after being crushed or treated and stacked into heaps if uniform distribution of the cyanide leach solution is to be achieved. Gold and silver ores containing excessive amounts of clays or fines generated by crushing are some of the most difficult to treat successfully by heap leaching. The presence of excessive amounts of slimes (generally classified as minus 50-micron or 270 Tyler mesh sieve size particles) in the heap leach feed will slow the percolation flow of the leach solution, cause channeling, or produce dormant or unleached areas within the heap. This may result in unreasonably long leaching periods and poor extractions. In extreme cases, the clays or slimes can completely seal the ore heap, causing the leach solution to run off the sides of the heap rather than to penetrate the ore heap. The problem of heap leaching ores containing fines can be aggravated during stacking and preparation of the ore heaps, because natural sorting of coarse and fine material occurs during these steps (Johanson, 1978). This phenomenon results in a concentration of ore fines at the center of individual ore piles and a concomitant concentration of larger rock fragments on the lower slopes and base of the piles. When the individual piles within the heap are leveled off prior to installation of the sprinkling system which delivers the leach solution, additional segregation occurs as the fines sift through the coarser ore particles. The segregation results in localized areas or zones with marked differences in permeability. As a consequence, the leach solutions follow the path of least resistance, percolating downward through the coarse ore regions and bypassing or barely wetting areas that contain large amounts of fines or slimes. Effective utilization of marginal gold and silver resources through heap leach processing requires the development of new methods in order to achieve more uniform size distribution during ore heap preparation and better slime control during leaching.

Jan 1, 1988

By Earle J. Klohn

INTRODUCTION The paper presents a broad overview of the geotechnical site studies required for siting uranium tailings dams. These studies, which are interdisciplinary in nature, touch upon such related fields as: hydrogeology, hydrology, and seismicity. Tailings dams are commonly used to develop tailings ponds for the storage of the waste products generated by mine milling operations. In the past, most tailings ponds have been developed either above ground on dry land, or in existing lakes. In the United States a majority of the uranium mines are located in arid or semi-arid regions and past practice has been to store the wastes above ground on dry land (1,2). Currently, the United States Nuclear Regulatory Commission (N.R.C.) recommends below ground disposal of uranium waste products, although they indicate that they will consider above ground alternatives (3). In Canada many of the existing uranium mines are located in a wet environment and past practice has been to use small lakes and depressions as tailings ponds (1,4). However, current practice in Canada leans towards above ground, dry-land storage (5,6,7), and the Atomic Energy Control Board (AECB) guidelines (5) indicate this to be the preferable method. In B.C., where a moratorium on uranium mining has been declared by the Provincial Government, there are no existing uranium tailings ponds. However, both the formerly proposed Birch Island and Blizzard uranium developments would have used dry land storage. Most of the existing non-uranium mill wastes in B.C. are stored behind tailings dams on dry land. The waste products delivered to the tailings pond comprise, the ground-up rock that remains after most of the uranium values have been removed and the excess chemicals used in the milling process. These waste products, which are called "tailings", are normally mixed with water to produce a slurry and then pumped to the tailings pond. Since the uranium recovered constitutes only a small percentage of the ore (usually less than 1%) (8), large quantities of waste rock and associated transportation water are discharged into the tailings impoundment area. Consequently, relatively large tailings pond areas are required for the uranium tailings. In recent years, major advances have been made in the design, construction, and operation of non-uranium tailings storage facilities (9,10,11,12,13,14, 15). These improvements have been based on combining the latest advances

Jan 1, 1980

By Rod A. Levander, Kenneth B. King

INTRODUCTION The Panna Maria Uranium Project is located in South Texas, between San Antonio and Corpus Cristi, approximately 10 kilometers (6 miles) north of Karnes City, Texas. The tailings disposal facilities are located immediately south of the mill area and the central portion of the west pit. The mine and mill drainage pond is located north of the tailings pond. Location of the facilities is shown in Figure 1. The tailings pond is a disposal area for mill process wastes and has a capacity for storage of approximately 9 million metric tons (10 million tons) of tailings. This capacity is adequate for approximately 10 years of milling at a maximum rate of 2,700 metric tons (3,000 tons) per day. The tailings disposal facilities were designed to essentially eliminate discharge of contaminated waters to preclude degradation of surface streams or ground water. Water levels in the ponds will be maintained. through reuse in the mill and by evaporation. WASTE CHARACTERISTICS The sources of waste that is stored in the tailings pond include runoff from the mill area and tailings from the mill processing. The tailings consist of a sand slime slurry; the percentage passing the No. 200 sieve varies depending on the ore material, and it is generally in the range of 10 to 25 percent. The tailings have a density of approximately 1.2 metric tons per cu m (75 lb per cu ft) and an average specific gravity of 2.55. The liquid effluent from the mill consists of waste solutions from the grinding, leaching, extraction, and washing circuits of the mill. These solutions have an initial pH of 1.5 to 2.0 and contain the remnants of the leaching agents used in the mill process, sulfates, some silica as the primary dissolved solid, and trace quantities of soluble metals. This liquid is discharged with the solids into the tailings pond and is diluted by rainfall and runoff from the tailings dam. Runoff from the mill area, drainage from the mine area, and de-oiled water from truck washing facilities is discharged into the mine and mill drainage pond. Runoff from the mill area drains approximately 28 hectares (70 acres) from offices, shops, the mill site, the ore pad, haul roads, and adjacent areas. Mine drainage is collected in the mine area and pumped to the mine and mill drainage pond.

Jan 1, 1980