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By G. Davis

Mineral properties and mineral firms often trade at a market value that is significantly greater than the value indicated by discounted cash flow (DCF) techniques. A possible explanation is that DCF analysis does not consider the value derived from managerial flexibility. Presumably, then, at least some of the difference between DCF value and market value is due to managerial flexibility. This paper surveys the recent attempts to empirically quantify the value of managerial flexibility using option pricing theory. The results indicate that managerial flexibility, at least as measured by the option pricing methodology, falls well short of explaining the gap between DCF value and market value.

Jan 1, 1995

By E. P. Carman

1. DAVENPORT, S. J. Bibliography of Bureau of Mines Publications Dealing With Health and Safety in the Mineral and Allied Industries, 1910--46. Tech. Paper 705, 1948, 154 pp. 30 cents. 2. FJELDNER, A. C., FISHER, P. L., AND POLLOCK, M. B. Bibliography of Bureau of Mines Investigations of Coal and Its Products, 1940 to 1945. Tech. Paper 698, 1947, 53 pp. 15 cents. 3. GOOD, J. E., ABREU, ALVARO, AND FRASER, THOMAS. The Coal Industry of Brazil. Part 1. General Economy, Production, and Marketing. Tech. Paper 713, 1949, 38 pp. 20 cents.

Jan 1, 1954

By WILLETT G. MILLERS

GENERAL RECEPTION COMMITTEE.-Willett G. Miller, Chairman; F. G. B. Alan, Hon. Frank Cochrane, Eugene Coste, Thomas W. Gibson, Cyril W. Knight, J. C. Murray, 0. N. Scott, Alan Sullivan, J. B. Tyrrell, J. W. Wells, A. B. Willis. COBALT RECEPTION COMMITTEE.-Arthur A. Cole, Chairman; Will. Ask with, R. W. Brigstocke, Robt. Bryce, Fred Coombs, M. I. Culbert, I. R. Drummond, J. W. Evans, A. Ferland, F. N. Flynn, E. L. Fraleck, S. R. Heakes, Joseph Houston, D. L. Jemmett, I. R. Jones, Major Leckie, Capt. Jack Leckie, R. W. Leonard, W. H. Linney, Alexander Longwell, Frank Loring, Murdock McLeod, John Martin, D. B. Rochester, W. E. Running. COBALT RECEPTION COMMITTEE (Ladies).-Mrs. A. A. Cole, Mrs. A. Edwards, Mrs. R. Jennings, Mrs. S. H. Logan, Mrs. A. Longwell, Mrs. H. F. Marsh, Mrs. J. Smith. SUDBURY LOCAL COMMITTEE.-Mayor L. O'Connor, Chairman; S. Fournier, Secretary; A. H. Beath, W. J. Bell, F. B. Bennett, D. M. Brodie, J. S. Buchanan, F. C. Busby, Wm. Chalmers, R. Dorsett, W. A. Evans, John Frawley, J. S. Gill, A. B. Gordon, J. G. Henry, T. N. Kilpatrick, Major Leckie, Chas. McCrea, John McLeod, Wm. McVittie, R. Martin, R. S. Mitchell, J. H. Morin, J. A. Orr, James Purvis (President Board of Trade), C. R. Reid, Major Smith, W. W. Stull, J. F. Templeton, S. E. Wright. The first session, held in the Banquet Hall of the King Edward Hotel, was called to order Tuesday, July 23, 1907, at 2.30 p.m., President John Hays Hammond presiding. Prof. Willett G. Miller, chairman of the General Committee, introduced Alderman J. J. Graham, who, in behalf of the City of Toronto, extended a hearty welcome to the members and guests of the Institute. To this welcome, President Hammond replied in a few well-chosen and hearty remarks. In the hall in which the session was held there was exhibited a fine, full-length, life-size portrait of Dr. Rossiter W. Raymond, in 1871 Vice-President and acting President, in 1872, 1873 and 1874 the elected President, in 1876 and 1877 Vice-President, in 1883, by appointment of the Council, and for the last 24 years by annual election, Secretary, of the Institute. Dr. James Douglas, of New York, N. Y., on behalf of numer-

Sep 1, 1907

By F. W. Lee

A GREAT CURTAILMENT of field activities among the geophysicists occurred last year, especially in prospecting for the common metals. In gold, however, an "outstanding achievement . . . was made by the engineers of Consolidated Goldfields. Here the suboutcrop of the Main Reef Series was traced from Middelvlei through properties of the westward area, a distance of from 30 to 40 miles. Here Drs. Reineche and Krahman prospected with the aid of a sensitive magnetometer and established the singularities of the various beds which heretofore had not been sufficiently appreciated. Several underlying shale beds were used to determine this suboutcrop under the dolomite. This area promises to be the equivalent of one-half the size of the present gold fields and to rank in value with the Far East Rand." The present temperature compensated magnetometers permit accurate field observations to less than 5 gammas. Since magnetic anomalies may have their origin due to a change of elevation as well as to the outcropping of a bed of another magnetically different material, intimate geological knowledge is of great assistance in the interpretation of these measurements. To what extent magnetic measurements reflect the basement when the material is homogeneous, consisting primarily of red granite, was determined by members of the Bureau of Mines and described by Dr. J. H. Swartz. Because of the diverse causes of magnetic anomalies, some of which were discussed and correlated by Stratton and Joyce upon known conditions, magnetometer measurements are often difficult to interpret.

Jan 1, 1933

By John C. Machisak

THIS INFORMATION CIRCULAR covers the calendar year 1055 and contains statistical data on employment and injuries pertinent to metal and nonmetal mining and to their mills and processing plants that are voluntarily reported annually to the Federal Bureau of Mmes. This report, unlike previous publications, lists not only production and development workers but also office employees associated with mining and milling or processing. The last publication m the series, Information Circular 7798, Injury Experience in the Metal and Nonmetal Industries, 1954, also contains unpublished injury and employment statistics for 1943 through 1953. The Bureau is authorized to request data on injuries and employment from operators in the metal- and nonmetal-mining industries. The information voluntarily submitted by these operators contributes immeasurably to the promotion of safety in the mineral mining industries as it discloses the hazards to which metal and nonmetal workers are continually exposed during mineral extractive operations.

Jan 1, 1959

By I. J. Wu

China’s land area, comparable in size to United States or Canada, contains diverse geological environments and mineral resource potential. The diversity in geological environments is such that the potential for developing many world-class mineral deposits in China is good. However, China’s mining sector was not open to foreign investment until the1990s. The long-term prospect for Chinese resource development is attractive because of China’s enormous population and cumulative demand for minerals. Approximately 33 foreign mineral companies, including 11 major internationals, are to various degrees active in China. Chinese mining laws and regulations pertaining to joint ventures with foreign companies are, from the international investment prospective, evolving slowly, but positively. This positive trend is continuing under the current government reform process, which is moving China towards a freer market economy. Although improving the enforcement of relevant laws and regulations is an ongoing process, the environment for mineral investment and joint ventures is increasingly more accommodating to foreign companies.

Jan 1, 2000

By Warren D. Longwill

All known resources within the four proposed RARE II additions to the Yolla Bolly-Middle Eel Wilderness in northwestern California occur in the Gig Butte-Shinbone study area (fig. 1). No mineral resources are Figure 1.--NEAR HERE. known in the East Fork, Murphy blade, or Wilderness Contiguous units. About 2,400 tons (2,177 t) of subeconomic manganese resources averaging 9.5 percent manganese have been estimated at the Blue Jay Mine in the Big Butte-Shinbone unit. In addition about 9,700 tons (8,793 t) of subeconomic chromium-nickel-cobalt resources in thin laterite soil at the Grubstake Prospect contain about 1.27 percent chromium oxide, 0.45 percent nickel, and 0.03 percent cobalt. Adjacent Ultramafic rock outcrops have pods averaging 2.5 percent chromium oxide (Cr203); one pod contains about 40 tons (36 t) of indicated subeconomic resources.

Jan 1, 1981

Coal - Surface Mining Coal Preparation Coal Utilization Research and Development Health and Safety

Jan 3, 1976

By C. S. Allbright

This report gives the results of analyzing three groups of crude shale oils by the Bureau of Mines procedure:4/ (1) Oils produced by standard Fischer assay determinations on oil shales from Brazil (Paraiba Valley) and the United States (Colorado); (2) oils produced from Brazilian shale by different retorting methods; and (3) oils from high-temperature retorting of Colorado oil shale in the Entrained Solids retort. It is the second in a series presenting data obtained by analyzing crude shale oils from various sources. The series furnishes information on the general characteristics and compositions of a wide variety of shale oils. Use of a standard analytical method on all samples facilitates comparison of different oils. The 18 oil samples analyzed in this project comprised 3 from assays of Brazilian and Colorado oil shales in the Fischer retort, 9 obtained by processing Brazilian shale in various other units, and 6 from entrained solids retorting of Colorado shale at 1,000° to 1,500° F. The crude oils from Brazilian shale contained about half as much nitrogen as the Colorado oils. Properties of the Fischer assay oils from Colorado shales agreed with some data that relate grade of the oil shale with properties of the crude oil from the Fischer assay. Comparison of results from Fischer assays of oils from the foreign and domestic shales shows that the oil from Brazilian shale contains more low-boiling material and less residuum than either of the two from Colorado shale. This fact is reflected in lower specific gravity, viscosity, and carbon-residue values for the Brazilian oil. Retorting Brazilian shale in the Entrained Solids unit at 1,120° F. produced an oil whose boiling range was generally lower than the boiling ranges of oils obtained by processing in three other retorts at conventional temperatures. The quality of crude oils from high-temperature retorting of Colorado shale in the Entrained Solids process varies with retorting temperature. As the temperature is raised within the range 1,000° to 1,500° F., the amount of the naphtha fraction in the crude oil increases to about 35 percent and the aromaticity to 98 percent.

Jan 1, 1956

By Yasuo Ojima

The mainstream of copper smelting processes in the world today is a combination of Outokumpu type Flash smelting and PS (Pierse Smith) converting process. Presently it can be estimated that about 50% of the worldwide copper production is produced by the Flash smelting process and 80% by the PS converting process. PS converting process due to its operational flexibility and despite its batch character of operation has been widely used in many smelters for more than 100 years. However, an environmental issue has been pointed out related to this process because of the difficulty of handling the fugitive gases. Recently several copper smelters in the world have been newly construeted and others have executed major modification and modernization. The continuous converting process has been applied in many of them instead of PS converting process. This paper compares PS to the emerging continuous converting process and makes a prospect of the future of the copper converting process.

Jan 1, 2003

By S. L. Zekovic

This paper analysis the medium and long-term perspectives, framework and considered possibilities of sustainable development of RTB "Bor" (Copper mines in East Serbia) after consolidation in the period of transition. The copper mine was opened in 1903. and today is the best quality copper producer on Balcan. This paper are elaborates the problems of privatization, debt, investment, growth of copper production from own mines (and imported raw), opening of new mines, economical efficiency of production, markets, environmental problems and impacts of the recent industry consolidation. The RTB "Bor" is a serious hot spot in Serbia. Unsustainable trends and processes are identified, as follows: open-pit waste dumps, flotation tailings, mining and processing waste waters, air pollution; no efficiency (excessive) using nonrenewal resource in the copper production; inefficiency in the use of energy, water and other inputs in copper complex; transboundary character of emissions of dust; environmental degradation and quality of wide area and ecologically highly risk, etc. Analysing some trends and planning-developmental perspectives and development strategies of company, it might be assumed that in the forth coming period, in parts of the Serbia, the borders areas of Bulgaria and Romania, there is an anticipated increase of ecological risk.

Jan 1, 2007

The object of this program was to extend the capabilities of visual paging systems both in size and function. The system developed uses the mine pager phone line for communication, monitoring, and remote control. A central station, using a minicomputer, transmits signals by phase inversion modulation of a 16,384 Hz carrier to as many as 999 remote units. The remote unit addressed returns An echo to indicate that it is functioning and, in the case of monitor units, to convey the monitor data. Magnetically latched display dis[c]s, which can be seen from both sides when posted, are used for visual paging. Lists of the addresses of posted pages, unanswered pages, and non-echoing units are prepared by the central station computer. The system was designed to be intrinsically safe and should operate for three months on a 12-volt lantern battery.

Jan 1, 1980

By A. B. Hooker, J. W. Paul

"There was a time when any suggestion that the Davy flame (safety) lamp be discarded, would have evoked unlimited, criticism. However, that time is past.Investigations both here and abroad have shown conclusively that the Davy lamp does not have the necessary factor of safety against ignitions of mine gas, and England, the lost stronghold of the Davy lamp in Europe, has eliminated this lamp and substituted safer types.In the United States there are companies who still use the Davy lamp in spite of all that has been said and published as to the dangers connected with its use.Recently the purchasing agent of an anthracite coal company requested the Department of the Interior, Bureau of Mines, to pass upon the safety of some braise gauzes for use in a shielded Davy lamp. A shielded Davy lamp is an ordinary Davy safety lamp equipped with a circular brass shield that is attached to the lamp posts. This shield extends about one-half way around the gauze and one-half of the gauze height. The main purpose of the shield is to prevent the lamps being extinguished by a sudden increase in the velocity of the air current past the lamp.The brass gauzes submitted for this test represented two grades of brass - a yellow brass and a red brass. The analysis of these brasses was not determined. Two shielded Davy lamps that were submitted for the tests each had a steel gauze. These steel gauzes were also tested. Tests were made in horizontally moving mixtures of Pittsburgh natural gas and air at velocities of 400 to 1,000 feet per minute. The gas percentages used were 7%, 8.6%, and 11%. Tests were made with the lamp shield in two positions relative to the lamp and direction of flow of the gas-and-air mixture. In one position the shield was between the gauze and flow, as normally used. In the other position the shield was on the downstream side of the lamp. The tests were continued until one or more failures or gas explosions been obtained with each of the six gauzes. The results of these tests summarized as follows:"

Jun 1, 1923

By J. H. Soulé

"The Copper King copper-gold-silver deposit was discovered about 1880. Various individuals and companies have been interested in the deposit and considerable work has been done, although production, if any, has been small. The deposit is located in the western part of Laramie County Wyo., and is favorably nituated with respect to rail and truck transportation and high-tension power facilities.Mild summers and cold winters characterize the climate. Precipitation averages between 16 and 17 inches annually, with considerable snowfall in the winter. Permanent streams are small and most available water in being stored for use by Cheyenne, Wyo. Range grasses comprise the bulk of the vegetation, with small treed and shrubs common in the most rugged areas.The deposits lie upon land owned by Wyoming, now leased by a group of Wyoming and Colorado businessman constituting the Copper King Mining Co.Primary copper-gold mineralization seems largely confined to an equigranular, relatively fine grained gneiss that is part of a pre-Cambrian complex of metamorphic rocks ranging from schists to pegmatites. The copper minerals are oxidized to a depth of from 100 to 150 feet, with the occasional occurrence of secondary minerals at greater depths. The copper minerals chalcopyrite, malachite, chalcocite, bornite, cuprite(?), and some native copper were observed in Le deposit.In addition to the 4,030 feet of diamond-core drilling in 11 holes done on the deposit by private companies, the Bureau of Mines drilled 3 holes for a total of 2,630 feet. The sample results of this drilling plus available data from previous drilling and sampling are appended to this report."

Jun 1, 1955

By W. H. Oppelt

The continuous gasification of lignite in an externally heated alloy-steel re-tort was investigated by the Bureau of Mines, Grand Forks, N. Dak., from 1945 to 1951. The main objective of the long-term experimental program was to obtain data on the mechanical performance of this type of gasification retort, particularly the alloy-steel heat-transfer surface of the retort, when operated on large pilot-plant scale. At the same time, extensive experimental data were obtained concerning the effect of process variables and the effect of a limited number of design modifications on gasifier performance. In the period covered by this progress report 4 pilot-plant runs totaling 2,879 hours of operation were completed with the rolled-plate, 310-alloy reaction tube. Over 30 million cubic feet of gas, having H2-CO ratios from 2.1 to 4.4, was made by the partial gasification of 636 tons of 1-1/2-by 3/8-inch natural lignite. Rates of gas generation were from 8,200 to 14,300 cubic feet per hour. Three of the four runs were carried out with the lowered gas offtake or continuous-annulus design modification of the gasification retort. In the final run of the series, gasification of lignite from seven different mines in North Dakota and Saskatchewan, Canada, was investigated at similar combustion-space temperatures and lignite and steam feed rates.

Jan 1, 1955

By Ralph H. Whaite

In undermined urban areas, new solutions to subsidence problems are being sought. The Bureau of Mines is investigating a hydraulic backfilling technique whereby fill material is pumped as a slurry through a closed system and widely distributed in inaccessible mine workings from a single borehole. A full-scale demonstration was completed in 1973 in Scranton, Pa., which is underlain by abandoned anthracite mines in several coalbeds superposed one above another. A 30-acre residential area was stabilized by injecting about 450,000 cubic yards of crushed mine refuse into two coalbeds through five injection boreholes. Nearly 200,000 cubic yards was injected through one borehole from which the material moved into the mine workings on all sides; the injected material reached a maximum lateral distance of 640 feet and filled mine openings from floor to roof. In the gravity-feed method formerly used to backfill inaccessible mine workings, quantities of fill injected per borehole averaged about 300 cubic yards. The gravity-feed method required many closely spaced injection holes and provided incomplete filling. The new method, designed for inundated mines, proved successful also in mine workings about mine-water pool level. Distribution of slurry through a buried pipeline minimized disturbance to the community.

Jan 1, 1975

By L. C. Brichta

The Melrose zinc-lead. deposit is in an area of structural disturbance of sedimentary rocks in the Melrose mining district in Cherokee County, Kans., 25 miles west of Joplin, Mo., adjacent to the northwest limits of the Tri-State district. Mining and milling in the Melrose district has been sporadic and. very limited, largely due to the high cost of exploration through great thicknesses of barren rock, 350 to 440 feet overlying the ore deposits. No mining has ever been done on the Melrose zinc-lead tract, but it has been drilled extensively. The drill-hole logy indicate extensive structural deformation, silicification, and zinc-lead deposits in the Boone limestone-chert formations of the Mississippian series, which is overlain by thick-bedded Pennsylvanian shale and sandstone. Analyses of samples from Bureau of Mines drilling indicate the ore minerals are sphalerite and galena with no evident oxidation. During the period from November 2, 1949, to March 13, 1950, the Bureau of Mines investigated the deposit by churn drilling and sampling 23 holes aggregating 10,405 feet of bore. Factual data on the investigation and logs of holes drilled by private parties and the Bureau of Mines are presented in this report.

Jan 1, 1951

By B. W. Gandrud

[The Bureau of Mines is conducting an extensive investigation of coal preparation in the Alabama coal fields in cooperation with the University of Alabama coal-mine operators. In this investigation the drainage characteristics of typical coals from the Warrior and Cahaba fields were studied]

Jan 1, 1941

By Fred Heivilin

A symposium on the characterization and toxicology of mineral dusts was held Sept. 19 and20 in Washington, D.C. The symposium was held to update the minerals industry, the health community, government agencies and academia on the technical, health and regulatory aspects of minerals to be evaluated by the International Agency for Research on Cancer (IARC).In October 1996, the IARC met in Lyon, France, to discuss and prepare “Volume 68 of the IARC Mono-graphs on the Evaluation of Carcinogenic Risks to Humans on Silica, Silicates, Dusts and Organic Fibers.”

Jan 1, 1996

By C. P. Bowie

For years many oil producers have believed that often low-pressure oil- and gas-bearing strata have been over coked in fields where the rotary system of drilling has been used. Collom3/ gave as a reason for this con¬dition that because the mud fluid was thick, the oil or gas stratum was plastered and sealed as the tools passed through it and no oil showed at the surface. Although this observation was made 15 years ago, it may often still be true notwithstanding modern developments in coring and electrical logging. Operators have believed, also, that mud fluid does not solidify behind the casing. Lewis and McMurray4/ stated: "All the evidence obtainable from practical experience points to the fact that the mud fluid properly mixed and employed does not solidify behind the casing, even in deer wells and after long periods."

Jan 1, 1937