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By Rodney D. Rosenkranz

Energy consumption in domes tic copper production has increased nearly 60 percent in the last 10 years, reaching approximately 175 trillion Btu in 1973. Energy required to produce 1 pound of copper rose from nearly 41,000 Btu in 1963 to nearly 50,000 Btu in 1973. Production from lower grade ores and strict pollution control regulations have contributed to this increase. Each stage of copper production has been analyzed to determine total energy consumed, energy mix required, cost of the energy, and recent or proposed changes in operations which may affect the consumption of energy by the copper industry. Data have been gathered from a recent Bureau of Mines canvass of the industry, from visits to copper operations, and from conversations with copper industry officials.

Jan 1, 1976

By Jan C. Still

The Glacier Bay subarea is that part of the Juneau Mining District (JMD) within Glacier Bay National Park and Preserve (GBNP). It is the western portion of the JMD and consists of the land between the Fairweather Range crest and the Takhinsha and Chilkat Ranges crests (excluding that land east of Excursion Inlet.) Figure B-1 shows the area. It is bounded on the north by the Alaska-British Columbia International boundary, to the south by Cross Sound and Icy Strait, and contains Glacier Bay. During 1975 -1977 the Bureau conducted a detailed study of the occurrences, prospects, and deposits in GBNP (B_4).2 This work was in cooperation with the U.S. Geological Survey (USGS) under the provisions of the Wilderness Act (Public Law 88-577). As a follow up to this earlier Bureau work, limited studies were conducted, during 1985 and 1986, as part of the JMD study. This report covers the most important aspects of the earlier studies and the 1985 and 1986 studies. ACCESS The Glacier Bay area may be reached through Gustavus airport, a paved strip which is serviced by scheduled jet airliners in the summer and air taxi services year-round. The airport is connected to Bartlett Cove (GBNP headquarters) by an all-weather road. No other roads exist in the area except a skid road to the LeRoy Mine and mill in the Reid Inlet area. Much of the Glacier Bay area is accessible through the salt water inlets and fjords which are part of Glacier Bay. Cruise ships, charter boats, and fishing boats visit these inlets and fjords during the summer months. Elevations within the area range from sea level to over 15,000 feet in the rugged Fairweather Mountain Range. More remote areas are accessible by small boat, foot, or helicopter. Glacier ice is a year-round hazard to navigation in Glacier Bay, and during the winter months some of the more northerly inlets are frozen.

Jan 1, 2012

By C. E. Gregory

In terms of a Research Proposals supported by a Grant Agreement dated 30 June 1973, the author was commissioned to prepare an annotated bibliography of mine fires. The main objective was to conduct a comprehensive program of library research and search of official files to prepare a list of articles dealing with actual occurrences of mine fires. This bibliography as now completed includes an annotated reference from each article or report cited, underlining the cause, extent, methods used, procedural errors made, results achieved, ventilation effects, and lessons learned from the operation of subduing the particular fire.

Jan 1, 1974

By Richard F. Hewlett

Engineers at the Bureau of Mines Denver Mining Research Center have been a research program investigating the theory and application of mine sampling. Part of this program is an investigation of the efficiency of sampling methods that involves development of sampling-method theory through simulating ore-deposit samples and assays, using - electronic digital computer. Theoretical developments are checked against actual ore-deposit sampling, assay, and production data by the commonly used polygonal and triangular methods of computing grade and tonnage of ore reserves. To speed the computing procedures, a program has been developed utilizing a medium-size digital computer for computing ore reserves by the polygonal method. This program calculates nine prismoids per minute at a total cost of $0.21 per prismoid. The complete program, written for an augmented IBM 650 computer, is described in detail; it can be used without change for computing ore reserves for a low-grade deposit. Modifications necessary to convert the program to compute ore reserves for virtually any other type of deposit or grouping of ore horizons also are given; however, the program is limited to using only vertical drill-hole data.

Jan 1, 1962

By R. Karl Zipf, Suresh Bhatt

Highwall mining is an important coal mining method. It appears that upwards of 60 highwall miners are presently in operation, and they may account for approximately 4% of total U.S. coal production. A review of the Mines Safety and Health Administration (MSHA) data over the 20 year period from 1983 to 2002 identified 9 fatalities attributable to auger and highwall mining of which inadequate ground control accounted for 1/3. In the past 5 years, 1 fatality occurred in highwall mining. Estimates of the manpower requirements in highwall mining suggest that its fatality rate is essentially the same as for surface coal mining, thus highwall mining appears to be a very safe modern mining method. Highwall stability is the major ground control related safety concern, and operators are required to develop and follow an appropriate highwall mining ground control plan. The plans usually specify the following geotechnical parameters: hole width, maximum hole depth, maximum overburden depth, seam thickness, web pillar width, barrier pillar width and number of holes between barriers. Calculated web pillar stability factor exceeded 1.3 for most designs evaluated. This study examined records from 5,289 highwall miner holes with a total completed footage of about 2,560,000 feet to understand the reasons for early pull out. Average lost footage is typically about 20% of planned footage. Only 35% of the holes reached planned depth, and 20% were short due to rockfalls. Water and adverse geology accounted for 15% of the losses. Mechanical/electrical problems, guidance, and slope stability problems accounted for the remaining 30%. Web pillar stability factor for these holes also exceeded 1.3 in 95% of cases. Best practices to avoid trapped miners include: avoid mining in stream valleys, avoid mining near outside corners, careful alignment of each hole and the use of an onboard guidance system. Several issues in highwall mining ground control require further investigation including highwall mining through old auger workings, highwall mining near old underground mines, multiple-seam and multiple lift highwall mining and finally the size and frequency of barrier pillars.

By T. F. Myners

This paper, describing the concentration methods and costs of Witherbee, Sherman and Company at Mineville, N. Y., is one of the series of papers on milling methods and costs being prepared by the United States Bureau of Mines. It deals principally with the production of high-grade concentrate. ACKNOWLEDGMENT The author is indebted to C. F. Jackson, principal mining engineer, United States Bureau of Mines, to A. M. Cummings, general superintendent of Witherbee, Sherman and Company, and to the company's engineering staff, for assistance in preparing this paper.

Jan 1, 1932

By Anthony Iannacchione, Christopher Mark

Residents of Maxwell Hill, a suburb of Beckley, West Virginia, reported from January until March of 1988 a series of earth tremors. The tremors rattled dishes, and the noises associated with tremors were sometimes loud enough to wake people at night. These events were puzzling because Beckley is in an area of low seismic activity. Maxwell Hill is located above abandoned coal mines, though no direct subsidence damage to surface structures has been documented. A research program was initiated to determine whether subsurface ground movements associated with the abandoned mines could be responsible for the seismic activity experienced at the surface. A hypothesis is proposed which states that seismic disturbances can be caused by abandoned mine failure when two conditions are met. First, some instability must exist at the mine level. The most likely cause of instability is the failure of pillars of coal that were left for support at the time of mining. Second, subsurface movements can result in significant seismic activity only when the rock above the mine contains at least one very strong and brittle layer that is prone to fail violently through rupture or fault slip movement. Analysis of the data indicates that both hypothesized conditions for mine-related seismicity appear to have been satisfied in the case of Maxwell Hill. It has therefore been concluded that the earth tremors experienced by Maxwell Hill residents probably are related to the abandoned mines. Analysis of the potential magnitude of these events indicates that they are unlikely to cause significant surface danlage. The probability that future events will disturb the residence of Maxwell Hill should be quite low based on the identified mechanism.

By A. E. Raddatz

The Bureau of Mines is investigating methods for recovering tungsten from domestic resources. A calcine-quench-leach (CQL) technique was developed for the extraction of tungsten from the Golconda, Nev., hot springs ores. The deposit contains disseminated tungsten that cannot be beneficiated by conventional techniques and must be treated by hydro-metallurgical methods. The CQL procedure consists of calcining the ore at 900° C for 3 hours, quenching in a solution containing 1.5 parts of Na2C03 and 1.5 parts of NaOH per part of WO3 in the ore and at a solution-to-ore ratio of 3 to 1, leaching at 200° C and at 250 psig for 3 hours, and filtering and washing the residue. A series of closed-circuit batch tests showed that 92 pct of the tungsten was extracted from a sample containing 2.32 wt-pct W03. The pregnant solution contained 11 g/l W03.

Jan 1, 1982

By Patrick J. Coleman, John C. Kerkering

Problem: Mining in the United States remains one of the most hazardous industries, despite significant reductions in fatal injury rates over the last century. Coal mine fatality rates, for example, have dropped almost a thousand fold since their peak in 1908. While incidence rates are very important indicators, lost worktime measures offer an alternative metric for evaluating job safety and health performance. The first objective of this study examined the distributions and summary statistics of all injuries reported to the Mine Safety and Health Administration from 1983 through 2004. Over the period studied (1983 2004), there were 31,515,368 lost workdays associated with mining injuries, for an equivalent of 5,700 person years lost annually. The second objective addressed the problem of comparing safety program performance in mines for situations where denominator data were lacking. By examining the consequences of injuries, comparisons can be made between disparate operations without the need for denominators. Total risk in the form of lost workday sums can help to distinguish between lower and higher risk operations or time periods. Method: Our method was to use a beta distribution to model the losses and to compare underground coal mining to underground metal/nonmetal mining from 2000 to 2004. Results: Our results showed the probability of an injury having 10 or more lost workdays was 0.52 for coal mine cases versus 0.35 for metal/nonmetal mine cases. In addition, a comparison of injuries involving continuous mining machines over 2001 2002 versus 2003 2004 showed that the ratio of average losses in the later period to those in the earlier period was approximately 1.08, suggesting increasing risks for such operations. Discussion: This denominator free safety measure will help the mining industry more effectively identify higher risk operations and more realistically evaluate their safety improvement programs. Impact on Industry: Attention to a variety of metrics concerning the performance of a job safety and health program will enhance industry's ability to manage these programs and reduce risk.

By E. P. Youngman

In the absence of any subsequent enactment of mining legislation, the Turkish mining law in effect in 1914, when Iraq became a British mandate, is still operative. The Constitution, or Organic Law, of Iraq, adopted by the Constituent Assembly on July 10, 1924, in articles 113 and 114, provides that:3 Ottoman en laws date and thao remained and lave pub- lished on or after that date and which have remained in force in Iraq u to the time of the publication of this law shall remain in force in Iraq' so far as circumstances permit, subject to any modi- fication or repeal in conformity with the proclamations, regula- tions, and laws referred to in the following article, and until they are altered or repealed by the legislative power or the High Court issues a decision rendering them null and void in accordance with the provisions of article 86. (Art. 113.) All proclamations, regulations, and laws by the Commander-in- Chief of His Britannic Majesty's Forces in Iraq, the Civil Commis- sioner, and the High Commissioner, and those issued by the Govern- ment of His Majesty King. Faisal, during the period between Novem- ber 5, 1914, and the date of the coming into force of this Consti- tution, shall be considered to be valid as from the date on which they came into force... (Art. 114.) 4 According to a German authority, it is the Turkish law of March 26, 1906, that, with a few modifications, is still in force. This law (similar to the French law of 1810) is discussed in a separate section of this paper.

Jan 1, 1933

By Efrem R. Reeves, David C. Byrne

This study was conducted as part of a project involving the evaluation of a new type of noise exposure monitoring paradigm. Laboratory tests were conducted to assess how “nonstandard” dosimeter microphones and microphone po­sitions measured noise levels under different acoustical condi­tions (i.e., diffuse ?eld and direct ?eld). The data presented in this article re?ect measurement differences due to microphone position and mounting/supporting structure only and are not an evaluation of any particular complete dosimeter system. To varying degrees, the results obtained with the dosimeter microphones used in this study differed from the reference results obtained in the unperturbed (subject absent) sound ?eld with a precision (suitable for use in an ANSI Type 1 sound level meter) 1/2 -inch (12.7 mm) measurement microphone. Effects of dosimeter microphone placement in a diffuse ?eld were found to be minor for most of the test microphones/locations, while direct ?eld microphone placement effects were found to be quite large depending on the microphone position and supporting structure, sound source location, and noise spectrum.

By James P. Ulery

In This Chapter [Geologic features associated with anomalous methane emissions Gas outbursts and blowers Methane drainage strategies for mitigating anomalous methane emissions and General considerations for a methane drainage program] This chapter summarizes how certain geologic features may be associated with unexpected increases in gas emissions during coal mining. These unexpected emissions have the potential to create explosive conditions in the underground workplace. Also discussed are the generally used practices to alleviate potential hazards caused by gas emissions associated with these geologic features. INTRODUCTION Unforeseen mine gas emissions in quantities sufficient to create hazardous conditions have been attributed to sources outside the mined coalbed since the first documentation of methane explosions in coal mines [Payman and Statham 1930]. Geologic features such as faults have long been recognized as conduits for gas flow from strata adjacent to mined coalbeds [Moss 1927; Payman and Statham 1930]. Other features such as sandstone paleochannels, clay veins, and localized folding have also been recognized for their impact on gas emissions into mine work-ings [Darton 1915; Price and Headlee 1943; McCulloch et al. 1975; Ulery and Molinda 1984]. The fact that strata adjacent to mined coalbeds can emit large quantities of methane gas into mine workings is not surprising from a theoretical perspective. Many researchers have recognized that during the burial and diagenesis of the organic matter forming today’s minable coalbeds, similar dispersed organic matter in adjacent strata has produced methane in quantities far exceeding the storage capacity of the coal and surrounding rock [Juntgen and Klein 1975]. It is not surprising then that large quantities of methane can remain trapped in these strata. A potential hazard occurs when mining of a nearby coalbed causes pressure differentials and mining-induced fractures conducive to gas flow into the mine workings from these strata. This gas flow may be facilitated or temporarily impeded by the presence of geologic structures or anomalies.

Jan 6, 2006

By James P. Ulery

Explosions in U.S. coal mines have caused death and injury to miners and destruction of workings since the first reported explosion in 1810. These explosions are caused when buildups of explosive gas and/or dust in the mine are ignited by the presence of a flame or spark. Methane gas is inherently generated and held by adsorption in coal and is normally liberated during mining. Because this gas is explosive in the range of 5%–15% by volume, fresh air is constantly supplied to the working face to prevent the methane/air mixture from reaching this explosive range. The required amount of ventilation air is based on estimates of gas release under normal conditions. Occasionally, unanticipated and unusually high emissions are encountered, which, despite normal ventilation controls, result in an explosive mixture that a spark from a cutting bit or electrical equipment can easily ignite. Investigations have shown that such emissions are often associated with anomalous geologic features or conditions. Although most operators are aware that certain geologic features may adversely affect productivity, few are aware of their potential as a gas emission hazard. This report presents a historical framework detailing the impact of geologic features on excess gas emissions and resultant mine explosions. It also provides operators with specific information on recognizing and alleviating potential hazards from methane emissions related to these geologic features.2

Jan 4, 2008

8053. Andreev, B. A. Zakashanakii, M. S., Samsonov, N. N., and Fotiadi, E. E. A Textbook of Gravitational -Surveying, (in Russian). Gosgeolizdat, Moscow-Leningrad, 1941, 432 pp. This textbook was written at the suggestion of-the faculty of geophysical exploration of the Leningrad Mining Institute. It contains two parts: (1) Theory and technique, and (2) Applications to geology and exploration. The features bringing; the text up-to-date include: (a) Description of the principal modern gravimeters; particular attention to the method of simultaneous oscillation of 4 pendulums; (b) discussion of the aperiodic oscillation of torsion balances; outline of the construction of variometers Z -20 and Z-40; (c) material for aid in interpretation, such as reference-charts, formulas with their derivation, atlas of theoretical curves, and examples of interpretative calculations; (d) considerations in the planning of surveys and the densities of various rocks; and (e) detailed analysis of significant examples. The text is provided with a bibliography, V. S.

Jan 1, 1946

By C. O. Karacan, S. J. Schatzel, W. P. Diamond

In coal mining, longwall mining is a preferred method to maximize production by extracting large blocks of coal that have been outlined with a set of development entries. In U.S. mines, longwall panels are typically 305 m (1,000ft) wide (with a continual trend towards even wider panels), and usually over 3,050 m (10,000ft) in length. The increasing size of longwall panels, while helping to increase coal production, may also increase methane emissions due to the exposure of the mining environment to a larger area of fractured, gas-bearing strata. Thus, understanding the impact of increased panel widths on methane emissions, and designing gob gas ventholes and bleeder systems accordingly, can enhance the safety of the underground workforce by reducing their exposure to potentially explosive accumulations of methane/air mixtures. As part of its mine safety research program, NIOSH’s Pittsburgh Research Laboratory has initiated a reservoir modeling effort to better understand the interaction of the various geotechnical factors influencing gas flow within and to the underground longwall mining environment. A focus of this modeling effort has been 1) the prediction of the incremental amount of methane emissions to be expected due to increasing longwall panel widths, and 2) optimizing gob gas venthole completion practices to capture more of the gas in the subsided strata above longwall panels before it can enter the ventilation system of the underground workplace. The history matching phase of the study has been carried out on a 381-m (1,250ft) wide panel in the Pittsburgh Coalbed. Simulations have also been completed for a 442 m (1,450ft) wide panel to estimate the incremental increase in methane emissions and the performance of current gob gas venthole placement configurations. Additional venthole placement configurations were simulated to investigate options for optimizing methane capture from the subsided strata above the wider longwall panel.

By W. R. Hardwick

This paper describes open-pit mining methods and practices at Copper Cities Division of Miami Copper Co, in Gila County, Ariz. It is one of a series being prepared by the Burea of Mines on mining methods, practices, and costs in various mining districts of the United States. A similar program, conducted from 1928 to 1939, provided technological information on the development and conservation of our mineral resources and assisted operators and engineers in evaluating and developing new mineral deposits. This circular contains a brief history of the district and describes the Copper Cities deposit, with particular emphasis on a detailed description of those characteristics--physical, economic, or engineering--that affect the choice of mining method. Prospecting and exploration, sampling and estimation of tonnage and values, development, and mining (including breaking ground, loading, hauling, ore control, and auxiliary operations related to mining) are described, Percentage of extraction, production rate, safety, first aid, Eire prevention, mine organization, and processing plant are discussed briefly, The final section gives such costs, on a percentage basis, as are available for publication. Where relevant, some information on the Castle Dome mine is included.

Jan 1, 1960

By G. W. Grove, E. E. Quenon

"INTRODUCTION During September, October, and November 1946 the Safety Division of the Bureau of Mines, off' the United States Department of the Interior, Pittsburgh, Pa., tested four new types of self-contained breathing apparatus and approved them in accordance with Schedule 13C. Approval was granted with the proviso that certain specifications outlined on the approval plate be made fully effective, and with the understanding that established safe practices in training in the care and use of self-contained breathing apparatus are of major importance.The excellent records made during the past 30 years in the safe use of self-contained breathing apparatus, some of which required the almost continuous wearing of apparatus during several hours daily for days, weeks, or months, may be attributed largely to the Bureau's system of rescue organizations, selection of physically fit rescue workers, effective training, and educational work done in rescue and recovery operations during fires or following disasters and in the care and use of self-contained breathing apparatus. Loss of life during wearing of breathing apparatus was due almost invariably to poorly assembled or otherwise defective apparatus, poor physical condition of the wearer, or insufficient training or some incorrect procedure.The newly developed breathing apparatus are of much simpler design than the conventional type used for the past several years; however, it is just as important to select rescue crews carefully and to train them properly in the care, use, and limitations of the new types of apparatus as for the older long-established types, if anything like safety is to be achieved in using them. The Bureau of Mines considers that 1/2-hour and 3/4-hour self-contained breathing apparatus should be used only as auxiliary equipment in mine rescue and recovery work, and their capabilities and limitations should be well understood by those who wear them."

Jul 1, 1947

By Lorraine B. Burgin

This study by the Bureau of Mines documents the leadtime required for preliminary and detailed exploration, development of the mine, and construction of beneficiation and support facilities for selected copper deposits in Arizona. The time for major exploration ranged from 1 to 15 years, time for open pit development (or construction) was 1 to 4 years, and time for under- ground development was 4 to 8 years; one underground mine presently being developed may require 12 years to achieve production. Construction of the beneficiation plants required 8 months to just over 2 years. The data are supported by historical facts for each deposit during the leadtime stages from location of claims through exploration, construction, expansion, and leaching. The sequence of development and factors contributing to differences in the time spans are discussed. Histories are detailed for the Miami, Castle Dome, Copper Cities, San Manuel-Kalamazoo, and Twin Buttes properties; briefly summarized are the Pinto Valley, Miami East, Esperanza-Sierrita, Pima, and Mineral Park Properties. Each mining operation had its own pattern of development, and together they present a source of planning information for the development of other properties.

Jan 1, 1976

By Neldon L. Jensen

Although ASARCO Incorporated, the only domestic producer, had terminated copper smelting operations and associated recovery of byproduct arsenic trioxide at Tacoma, WA, in 1985, it shipped small quantities of both trioxide and metal from its remaining stocks in 1986. Imports for consumption of arsenic trioxide increased significantly, owing to increased demand for arsenical wood preservatives and the decrease in domestic shipments of trioxide. Prices remained unchanged throughout the year. Development of gallium arsenide integrated circuits, important in advanced military and commercial electronics circuitry, continued to gain momentum during 1986. Domestic Data Coverage.-Shipments of small amounts of arsenic trioxide and metal from remaining stocks by Asarco were reported voluntarily to the Bureau of Mines.

Jan 1, 1988

By J. Girard-Dwyer, T. Camm

Direct costs such as medical, legal, administrative, and worker’s compensation costs, property damage, lost earnings, and lost benefits are typically used to compute the economic impacts of occupational injuries. However, there are also a number of less obvious, indirect costs that substantially contribute to the overall loss costs. In fact, for every $1 of direct costs an estimated $3 to $5 of indirect costs are also incurred. This paper presents a systems approach that incorporates engineering, economics, psychology, and sociology in order to evaluate the total value of investments in safety. By studying the interrelated system comprised of the injured worker, their family and coworkers, as well as the organizational structure that was the setting for the incident, a methodology can be developed that will more accurately capture the true costs of mine injuries.