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By M. E. Kuchta

LKAB's Kiruna mine, located above the Arctic Circle in northern Sweden, is one of the world's largest underground mines, and it is one of the most modern. The Kiruna orebody is a high-grade magnetite containing about 80% low-phosphorous iron ore and about 20% high-phosphorous iron ore in situ. The mining method used is large-scale sublevel caving. Due to the blending of high-phosphorous ore with low-phosphorous ore during the extraction process, only about 20% of the run-of-mine ore can be used for the mine's low-phosphorous product. The blending process is highly irregular and difficult for the mine-planning personnel to predict. An algorithm was developed that uses principles of gravity flow to predict the run-of-mine phosphorous grades from the in situ geologic block model. The model can be used for both long- and short-term predictions.

Jan 1, 2003

By Virgil W. Carmichael

In the Fort Union formation of western North Dakota, eastern Montana and northeastern Wyoming there are immense tonnages of lignite and subbituminous coal that have not yet been evaluated in terms of present economic conditions. Continued expansion of United States energy requirements has focused ever increasing attention on this tremendous resource, particularly as efficiency in mining and transporting of coal, as well as in electrical energy generation and transmission have improved and as hydrogenation and gasification of coal approach economic feasibility. This "total energy" concept for coal includes all of the energy uses that coal offers and has resulted in mergers of oil and coal companies and acquisition of coal re- serves by oil companies, as well as by coal companies and others. There is no doubt that these coals are entering an exciting new era of exploration and development that will result in greatly increased production. As a matter of fact, increased consumption for energy generation is well under way and recognition of the economic feasibility of high-Btu pipeline gas and synthetic petroleum products from coal is imminent. As coal is gradually displaced in steam electric generation by the more exotic fuels and processes, it will be increasingly used as raw material for the synthetic petro-chemical industry and the organic chemical industry.

Jan 1, 1968

By Robert Turner

Gold and silver processing techniques are some of the oldest in the mining industry. Gold mining of high grade veins and deposits has existed for centuries. However, only with the higher gold prices in recent years and heap leaching techniques have the low grade gold and silver deposits become feasible to mine and process economically. By mining and hauling 3,600,000 tons of ore per year at an average grade of 0.03 ounces/ton gold and 0.385 ounces/ton silver, the Zortman- Landusky operations became profitable in 1982. To maintain profitably, a stripping ratio of less than one ton of waste to one ton of ore, and mine run ore placed on the leach pads which will yield approximately seventy percent go1 d recovery.

Jan 1, 1984

By Simon D. Strauss

The recession that began in late 1980 has proved to be not only prolonged and severe, but in certain ways unique in its effect on the mineral industries among the periods of economic slowdown experienced in the Western world since the end of World War II. This time almost all minerals have been affected. In previous business turndowns, by contrast, some mineral sectors have with-stood economic adversity well. They experienced little or no adverse effect-thanks either to a strong secular expansion in the markets for their particular product or to specific factors that caused demand to be well maintained. For example, aluminum, molybdenum, and nickel are three metals that enjoyed extraordinary growth in applications during the years 1946-1973. These metals were little affected during the recessions that occurred in that era. Similarly, coal did not suffer a pronounced drop in sales in the 1974-75 turndown because, with the price of oil rising sharply, a switch away from oil and back to coal was clearly indicated for some energy-intensive applications. Oil itself was largely impervious to the ups and downs of the business cycle until very recently. And the precious metals, gold and silver, have often been regarded as benefiting from reduced economic activity because labor becomes more available, productivity rises, and operating costs diminish. In the current recession, however, no major mineral has escaped the broad trend. The secular growth factors that were previously so evident for aluminum, molybdenum, and nickel have disappeared, at least temporarily. The stable pricing behavior that previously characterized all three of these commodities has been replaced by extreme price weakness and apparent inability of the major producers to continue their roles as market leaders. Coal and oil both have suffered from a sharp drop in energy requirements. There are those who now anticipate a collapse of the market control over oil prices so clearly exercised by OPEC since 1973. If oil prices are no longer effectively controlled by the governments of the exporting countries, then coal prices are also certain to be affected. And the combination of high interest rates, tight money, and a change in public perceptions of precious metals put the skid under gold and silver quotations in 1981 and early 1982. Although inflation has been viewed as the scourge of most Western countries ever since the oil crises of 1973-74, prices-in constant dollars-of most minerals have not risen. On the contrary, with the exception of the precious metals and oil, for most minerals the prices that prevailed at the end of 1982 were close to the levels of the Great Depression of the 1930s in constant dollar terms. Table 1 compares prices for copper, lead, zinc, and aluminum at the end of 1982 with the average prices in 1934, stated in constant 1967 dollars. This emphasis on prices for mineral commodities reflects the fact that profits of mining enterprises vary directly with the level of prices. Manufacturing and retailing enterprises march to a different tune. They establish sales prices based on costs. Their profits tend to vary with volume. Commodities are for all practical purposes fungible, that is the advantages of known brands in marketing manufactured goods have little application in a commodity market. Thus the individual seller of minerals is unable to establish his sales prices. Except where a monopoly is present, he must sell at the going market. His option is to abstain from selling if he finds the price unremunerative. In past recessions, some mineral producers chose to do precisely that-either accumulating a substantial share of their output in inventory or, in prolonged downturns, abstaining from production. During the current recession, however, private-sector mining companies did not have the option of accumulating inventories to any great extent. Capital costs for new mineral projects or for expansion of existing facilities have escalated at an alarming rate since the early 1970s. Added to this has been the heavy cost of installing pollution control or safety equipment to comply with the regulations adopted in most industrialized countries (and particularly the United States) since 1968. The consequence has been that the financial position of most major mineral enterprises in mid-1980 was already strained. To finance increased inventories meant incurring additional funded debt at high interest costs, thus impairing the concern's credit rating. Management Choices Private-sector managements have had to face up to the alternative of either continuing to produce at an unchanged rate and marketing output at unremunerative prices or reducing output. The latter has meant either operating at a curtailed rate, with con-

Jan 3, 1983

By James F. Fraser

Construction of a major linear project in any environment is difficult, at best. Construction of a major linear project which includes major subway elements, both cut and cover and tunneling, in the center of an urban environment, approaches the impossible. I believe such a project would be impossible for a private company or a privately owned utility for a variety of reasons. The major two reasons are the funding necessary for such massive projects and the myriad of individual interests associated with private ownership of land. Such projects are possible in the public sector only because the need for the project... as is the case with mass transportation in Atlanta. . .overrides the profit motive. Without the profit motive, private companies, whether utilities or not, are precluded from practical interest in the development of any project. While it is safe to conclude that a profit-oriented business would have no practical interest in developing such massive projects as may include major tunnels, it would be useful, I think, to compare some of the significant differences between private profit-oriented businesses, and an agency, or Authority, such as MARTA, in building a major linear project. SLIDE 1. Comparison of a Private Company and a Public Agency [Item Private Company Public Agency Simplified To make a profit To provide a pre Purpose scribed service]

Jan 1, 1979

By S. B. Patton

To fully utilize a ventilation simulator as a planning and production tool, the network database must keep pace with mining progress. By using AutoCAD's attribute-definition function, the branch data and node coordinates can be stored as part of the branch-diagram file, and updated with the drawing. Attributes are drawing entities that contain text which can be extracted in a standard spreadsheet format or as an ASCII text file. The data can be subsequently loaded into a ventilation simulator with plotting capabilities, such as VNETPC. This paper presents the methodology for using AutoCAD's attribute feature in a ventilation simulation.

Jan 1, 1994

By Gilbert A. Bonforte, Hugh P. Caspe, Tracy K. Lundin

The Narragansett Bay Commission (NBC) Combined Sewer Overflow Abatement Program is a major effort to address and mitigate discharges from combined sewer overflows in the Providence, Rhode Island area. The proposed system consists of three deep rock tunnel segments totaling 17.8 km (11.1 miles) in length that will provide 860,000 cu m (227 million gal) of storage at depths up to 99m (325 ft). This paper discusses 13.5 km (8.4 miles) of 6.64m (21.8 ft) finished diameter tunnel, four construction shafts, 19 dropshafts and one large diameter pump station shaft tapered from 1 5.2m (50 ft) at the surface to 27.4m (90 ft) at depth. All facilities are in preliminary design.

Jan 1, 1995

By Preston McGrain

Geologic maps are indispensable tools in the modern search for mineral and fossil-fuel resources. They are the first essential step in understanding the lithologic nature and structure of rock units that form the land surface and that lie beneath it. They provide the basic foundation for planning mineral resource exploration programs and form the superstructure from which subsurface investigations are projected. In view of the economic application of such maps, the Commonwealth of Kentucky and the Federal Government entered a formal agreement in 1960 to map Kentucky geologically on a scale of 1:24, 000, or one inch map distance equals 2,000 feet on the ground. A 7. 5-minute quadrangle would comprise the unit map area. A resolution which urged the preparation of a new geological map of the entire State was passed by the Kentucky Society of Professional Engineers in February 1959, and was presented to the Governor of Kentucky, the Legislative Research Commission, Kentucky Department of Economic Development (now Department of Commerce), Kentucky Chamber of Commerce, and Kentucky Geological Survey with a request for support and action. The request was subsequently endorsed and actively supported by numerous civic and professional societies as well as representatives of various facets of Kentucky government, commerce, and industry. Monies to initiate the program were appropriated by the next session of Kentucky legislature; this appropriation was matched by federal funds (Hagan, 1961). Kentucky's state-wide topographic mapping project was completed in 1956, just four years prior to starting the geologic mapping program. The recently completed modern 7. 5-minute, 1:24,000 topographic maps made ideal bases for plotting areal geology. Had they not been available, it is doubtful if a geo- logic mapping program so large and comprehensive could have been undertaken.

Jan 1, 1966

By Thomas Novak, Philip Johnson, Richard L. Sanford, Lloyd A. Morley

Macintosh use in mine-planning applications lags DOS machines since many users have made significant investments in hardware and training for other environments. Macintosh use is becoming more pronounced in many other industries, and com soft-ware is of at least the quality of that available for DOS machines and many workstations. This paper describes attributes of the Macintosh computer family as related to many mine-planning problems and solutions including software, memory considerations, workstations, DOS compatibility, and networking.

Jan 1, 1993

By V. R. Bovino

You have afforded me the challenge of saying something profound in 20 minutes that will stay with you for 20 years. My hope is that from this presentation you will extract ideas that will move you? out of your offices, into the mine to seize upon the concepts that we will discuss. Your challenge is to transform those concepts into action and give life to the ideas discussed here. The notion of achieving limitless productivity produces peak levels of enthusiasm in today's mining leaders. Highly-productive mines do not happen by chance --they are created by progressive leaders. The quest for productivity improvement, exclusively through capital investment and technological advances, is an incomplete process. Improvement, through capital and technology, is often not achieved because we fail to energize the true potential and commitment in our employees.

Jan 1, 1991

By C. Meyer, J. J. Eidel

Major gaps in understanding hydro- thermal systems remain after a century of studying fossil ore deposits and active geothermal areas. The periodically rejuvenated concept of "stacking" ore deposit types has never been verified by a continuous sample. Basal and marginal regions of both “fossil" and "active" hydrothermal systems normally lie beyond the limits of economic exploration, remaining inadequately exposed. Incomplete scientific under- standing of he vertical transitions clearly limits the efficacy of exploration programs for hydrothermal ores of all types. The Continental Scientific Drilling Committee's (CSDC) Panel on Mineral Resources has defined dedicated research objectives and add-on experiments to industry or government drill holes of opportunity.

Jan 1, 1988

By E. C. Roper

Landusky Mining, Inc. and Zortman Mining, Inc. are two registered Montana Corporations wholly owned by Pegasus Gold, Ltd. of Vancouver, B.C. The Zortman and Landusky Mines are located in the Little Rockies District of central Montana. The Zortman-Landusky mines produced 2,100 kg gold in 1982. A total of 3,250,000 t of ore per year are mined during the period March 1, to September 15, at an average grade of 1.04 gm/t (0.03 oz/t) gold and 13.4 gm/t (0.385 oz/t) silver at a cutoff grade of 0.35 grams of gold/ton (0.01 oz of Au/t) of ore. The stripping ratio during 1983 is anticipated to be 0.75/1 waste to ore. Combined average plant capacity of the two Merrill-Crowe plants is 9,840 lpm (2,600 gpm). The combined heap spray capacity of the two plants approaches 18,900 lpm (5,000 gpm). The mine employs approximately 200 people, about half of these work for the mining companies and the other half for the mining contractor, N. A. Degerstrom of Spokane, Washington. Net profit in 1982 for Zortman and Landusky Mining, Inc. approximated $4,900,000 at an average gold price of $11.40/gm.

Jan 1, 1983

By James K. Gowans

Polaris Mine, a Cominco Ltd. property located on Little Cornwallis Island, Northwest Territories, Canada, (Lat. 75°30'), is the world's most northerly base metal mine. Polaris Mine, which commenced operations in late 1981, is characterized by its unique process barge. The lead/zinc concentrator, powerhouse, shops, offices, dry and warehouse have all been incorporated on a 400 ft. long by 100 ft wide by 65 ft high barge. This process barge was constructed in Southern Canada, at Trois Rivieres, Quebec, then towed 3500 miles into its final resting place on the high arctic. This paper describes the unique design of the barge concentrator and deals with the start-up and continuing operation of the Polaris Concentrator.

Jan 1, 1984

By Robert L. Marovelli

Organizational development that attempts to simultaneously deal both with training and with job design parameters as they relate to mine health and safety, productivity, and quality of life is one of several areas of research that the Bureau of Mines is pursuing. The Bureau sees potential in this particular effort for reducing accidents and injuries, improving worker satisfaction and health, and increasing productivity.

Jan 1, 1981

By David R. Delling

Tenneco is a large, diversified, energy-based company which has grown rapidly during its forty year life. We're the youngest corporation among Fortune's top 20 companies. Tenneco Minerals Company is the division of the Corporation responsible for nonfuel minerals exploration, development and operations. Tenneco Minerals Company is headquartered in Lakewood, Colorado. Exploration offices are in Colorado, Nevada, Alaska, and Perth, Australia. We currently operate two gold mines in Nevada and a large underground trona mine and soda ash processing plant in Wyoming. The latter has a capacity of 907 000 tonnes per year of soda ash and is the subject of my presentation today.

Jan 1, 1984

By J. A. Ehler

Speed and torque control of standard A.C. induction motors can be accomplished using a variety of devices ranging from mechanical, hydraulic, and electrical. Also, the motor can be specified as an A.C. wound rotor or D.C. motor using the associated controls. Normally, any one of these drive types can be adequately used to provide the torque control necessary to accelerate a conveyor belt system. The selection will depend on the economics, experience, and preference of the designer or end user. These drive types will be presented from a functional and performance viewpoint to assist in the understanding of the available technology.

Jan 1, 1998

By W. Blake, J. Whyatt

Sixty years of rock bursting in the Coeur d'Alene district has taught painful lessons and led to a number of practical advances in controlling rock-burst hazards. This paper summarizes these lessons, concentrating on practical measures that have been successfully adopted to reduce hazards. These lessons are explained in the context of district mining history and current understanding of rock-burst phenomena. Overall, the paper provides the practicing mine engineer with an appreciation of rock-burst hazards and an overview of practical measures that can be used to control these hazards in the context of Coeur d'Alene district experience.

Jan 1, 2003

By Jerry Williams

GEORGE WEINMAN: At this time, our co-chair, Jamie Davis from Phelps Dodge, will come to the podium. JAMIE DAVIS: Our next speaker is Jerry Williams from Phelps Dodge, Morenci. Jerry is the maintenance planning supervisor and is in charge of preventative maintenance and maintenance scheduling. Jerry's group uses predictive tools to monitor and predict the equipment failure throughout the mine, from pumps to shovels to motors, you name it. The title of Jerry's talk is "If You're Not Using Predictive Tools, You're Behind the Curve." I’ll turn it over to Jerry.

Jan 1, 1998

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 Henry H. Rubin

Rubber and its contributions to the economic solutions of environmental problems in the minerals industry. The intelligent applications of "Rubber" to systems of noise abatement, vibration isolation, dust containment, weak and corrosion resistance has proven economically beneficial. Intelligent application requires a thorough understanding of the nature of the material, knowledge of the process wherein it is going to be applied, and consideration of the environmental conditions in which it will serve, for these determine the proper amount, type, compound and configuration for an economically successful application.

Jan 1, 1979