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Jan 1, 1981

By D. R. Babich, E. R. Bauer

Noise-induced hearing loss (NIHL) in mine workers, especially underground coal miners, continues to be a problem in the mining industry. The recently enacted MSHA noise standard, Part 62 – Occupational Noise Exposure (Federal Register, 1999), is aimed at reducing NIHL in the mining industry. The U.S. National Institute for Occupational Safety and Health (NIOSH) is conducting a cross-sectional survey of noise sources and worker noise exposures to address NIHL in various aspects of coal mining including surface mining, coal preparation plants and underground mining. In underground bituminous coal mining, noise surveys, consisting of full-shift worker noise exposure, time-motion studies and equipment noise profiling, have been completed on longwall and continuous miner sections in six underground coal mines. The studies revealed widely varying shift-to-shift worker exposures, with workers in certain occupations routinely exposed to potentially hazardous levels of noise. A summary of these studies is reported, including worker dose, source/dose relationships and equipment noise profiles.

By Donald O. Capstick

The local geology, the lack of recorded mining activity, and our field investigation and associated sampling indicate a low potential for mineral resources. Claim records and the literature review failed to show any lode or heavy mineral placer mining claim locations that are definitely in the area or anomalous mineral concentrations in the study area. Field investigations revealed no claims, prospects, or mineralized areas.

Jan 1, 1982

By James Ridenour

The Gearhart Mountain Wilderness and RARE II area 6225 encompass 22,823 acres (9,236 ha) of the Fremont National Forest in southern Oregon (fig. 1). The area was studied under the provisions of the Wilderness Act of 1964 (Public Law 88-577). The U.S. Bureau of Mines determined the mineral potential of known mines, prospects, or mineralized areas, while in a separate effort the U.S. Geological Survey made geological, geochemical, and geophysical studies. MINERALIZED AREAS The study area contains no mining districts or known claims. Nearby occurrences of uranium, base metals, perlite, mercury, and diatomite apparently do not extend into the study area. Reconnaissance pan samples reveal only trace amounts of gold. No anomalous economic minerals were found in heavy mineral fractions of samples from stream beds draining the area.

Jan 1, 1982

By Terry L. Muldoon

The report describes the development of preliminary requirement specifications for standardized operating controls for roof bolting machines used in underground coal mining. According to recent statistics, roof bolting continues to be one of the most hazardous occupations in underground coal mining. The two principal hazards to the roof bolter operator are the machine itself and roof falls during the bolting cycle. The lack of standardization of machine controls is a major contributor to this hazardous situation. Observations of roof bolting operations and discussions with roof bolter manufacturers coupled with detailed analyses of roof bolter control design specifications were performed during this study. Detailed roof bolter operator task analyses, commonality of control analyses, and classical link analyses were also performed. The results of these analyses were then used to produce preliminary requirement specifications for standardized controls.

Jan 1, 1980

By Shail J. Butani

In 1986, the Bureau of Mines conducted a probability sample survey, Mining Industry Population Survey, to measure such employee characteristics as occupation; principal equipment operated; work location at the mine; present job, present company, and total mining experience; job-related training during the last 2 yr; age; sex; race; and education. The population estimates are necessary to properly analyze the Mine Safety and Health Administration (MSHA) injury (includes illness and fatality data) statistics; that is, to compare and contrast injury rates for various subpopulations in order to identify those groups that are exhibiting higher than average injury rates. This report uses the survey's results to characterize the U.S. coal mining workforce from March through September 1986. A companion report, Information Circular (IC) 9193, "Characterization of the 1935 Metal and Nonmetal Mining Workforce:' provides similar information for the U.S metal and nonmetal mining industry.

Jan 1, 1988

By Lloyd A. Morley

This Bureau of Mines publication presents a comprehensive review of mine electrical power-system theory and practice. It discusses fundamental theory and the vital aspects to be considered in planning and designing mine electrical power systems. The report is divided into three major sections. The first presents the history of electricity in mining and the fundamentals of electrical phenomena and components. The second focuses on power-system components: motors, grounding systems, cables, and protective equipment and devices. The final section includes mine power-center equipment, switchhouses and substations, batteries, and mine maintenance.

Jan 1, 2003

By Charlie Wyche

In 1980, gold, silver, and pit and quarry construction materials were the principal minerals produced in the Dominion of Fiji. The combined value of these minerals totaled some $7.2 million,2 over 85% of all mineral production, Production of cement, sand and gravel, and quarry products continued to increase, but gold and silver production from Fiji's only operating mine declined slightly from the previous year's level. Mineral exploration has been carried out by U.S., Australian, British, Canadian, West German, and South African companies since the early 1960's, and a high level of activity was maintained throughout 1980. At the end of 1980, some 40 mineral prospecting licenses covering over 4,300 square kilometers were in force, and 19 applications were under consideration by the Mineral Resources Department. Total expenditures by mining companies on land base projects exceeded $6 million in 1980.

Jan 1, 1982

By Harold J. Bennett

This study was performed by the Bureau of Mines to evaluate the potential supply of primary copper from domestic resources. A tonnage-price relationship was developed indicating the quantity of copper that could be produced economically from known deposits at various copper prices and at various rates of return on the required capital investment. Costs of production are based on estimated capital and operating costs for mining, concentrating, smelting, and refining the copper. Total known recoverable copper resources are 189 million short tons of which 83 million tons could be economically recovered assuming a price of $0.50 per pound of copper, credit for the recovery of byproducts, and a 12-percent rate of return on capital investment. The quantities of recoverable byproducts associated with the 83 million tons of recoverable copper are molybdenum, 1.8 million tons, gold, 43 million troy ounces, and silver, 740 million troy ounces.

Jan 1, 1973

By Larry Patts, Jon Hummer, Jim Noll, Aleksandar Bugarski1, George Schnakenberg, Steve Mischler, Mike Crum, Shawn Vanderslice, Rick Anderson

This study is organized under the auspices of the Metal/Nonmetal Diesel Partnership formed by the National Institute of Occupational Safety and Health (NIOSH), the National Mining Association (NMA), the National Stone Sand and Gravel Association (NSSGA), the United Steel Workers of America (USWA) and the MARG Diesel Coalition. The ultimate objective of the study is to reduce the exposure of underground miners to diesel particulate matter (DPM) and gases, and to help in fulfilling the partnership’s goal of identifying technically and economically feasible controls to curtail particulate matter emissions from existing and new diesel powered vehicles in underground metal and nonmetal mines. The majority of current knowledge on the performance of the diesel particulate filter (DPF) systems and other control technologies is based on studies done under laboratory conditions, the results then being applied the results to on-highway vehicles. According to the best knowledge of the authors, only two comprehensive studies that were conducted recently at Noranda’s Bathurst Mining and Smelting Mine and International Nickel Company’s Stobie Mine under the sponsorship of the Diesel Emissions Evaluation Program [McGinn 2001, Bugarski and Schnakenberg 2001, Bugarski and Schnakenberg 2002] offered some insight into the problems associated with the deployment of modern DPFs to underground mining vehicles. The U.S. mining industry has expressed concern that this rather limited knowledge base is not sufficient to help them comply with the rule limiting DPM exposure of underground metal and nonmetal miners [30 CFR 57.5060 2001]. The partnership agreed that a series of comprehensive field evaluations of DPFs in several underground mines was needed to determine their viability of DPF systems and establish confidence in their performance. The first in this series of studies was the one conducted in Stillwater Mining Company’s Nye Mine, Nye, Montana. This study was conducted in two phases. The objective of the first phase was to establish the effectiveness of the selected technologies in reducing diesel emissions by using an isolated zone methodology. The objective of the second phase was to assess the effectiveness of diesel particulate filters in controlling the exposure of underground miners in actual production scenarios. As part of the first phase of the study a series of tests were conducted at Nye Mine from May 19, 2003 until May 30, 2003. The results of Phase I of the study are presented in this report.

Jan 1, 2005

By William O. Vanderburg

This paper gives the results of a reconnaissance of the mining districts in Pershing County, Nev., made from March 9 to April 1, 1936. During the field work nearly all of the mining districts in the county were visited, and considerable data were obtained on active and inactive properties. The report covers the location of the various mining districts, nature of the deposits, information on past

Jan 1, 1936

By Thomas K. Matson

The coal reserve base in the Western United States is presented for coalbeds amenable to extraction by underground mining methods. The Federal Bureau of Mines has abstracted data on the quality and quantity of coal resources/reserves from numerous State and Federal publications and modified such data as necessary to allow computer storage and retrieval. Tonnages are compiled by State, county, coalbed, and rank, and allotted to sulfur categories by statistical apportionment. The coal reserve base in those States west of the Mississippi River, amenable to underground mining, is estimated to be approximately 131 billion tons. Of this total, about 30.8 billion tons are bituminous coal, 100.2 billion tons are subbituminous coal, and 126.4 million tons are anthracite. Lignite is not considered for underground mining in this report. Included in this report is a glossary of terms applicable to a classification system for coal resources and reserves as jointly defined by the Bureau of Mines and U.S. Geological Survey. The purpose of this system is to provide for direct comparison or compilation of various resource/reserve data.

Jan 1, 1975

By Jr. Gabler

The U.S. Bureau of Mines (USBM) has developed a computerized commodity flow model for strategic and critical materials This flow model is generic and applicable to most commodities and amenable to updating supply, demand, and/or production data change. The original model, with slight modifications, was used to track the flow of chromium. This report follows the flow of chromium through its metallurgical, chemical, and refractory applications, and highlights areas where significant losses occur because of downgrading, export, or disposal. The study indicates that materials containing 451,769 mt of chromium were consumed, including 99,221 mt of chromium from recycling, Chromium losses from all causes in 1989 were estimated to be 345,347 mt from a variety of areas. These areas and their chromium losses are as follows: processing losses, 38,825 mt; processing-downgraded scrap, 18,227 mt; manufacturing losses, 18,128 mt; manufacturing-downgraded scrap, 56,595 mt; prompt scrap exported, 1,531 mt; obsolete scrap exported, 43,443 mt; recovery losses, 155,529 mt; and recycling losses, 13,069 mt. Recycled chromium-containing material accounted for 22 pct of the apparent consumption of chromium in 1989.

Jan 1, 1994

On June 20, 1972, Ocean Energy was awarded Contract No. H0220055, entitled Portable Task Luminaire System Development. Initially, this was a 12 month program consisting of three phases: Phase I -- Design of the Luminaire System and Battery Chargers, Phase II -- Fabrication of Prototype Units, Phase III -- Fabrication of Production Prototype Units and Battery Chargers. In addition to developing the Portable Task Luminaire System, however, this contract was amended a number of times in the course of the program to include the development of a Low Coal Portable Task Luminaire, a Rib Mounted Luminaire System, and a Machine Mounted Luminaire System, all based upon the same high frequency fluorescent lighting and safety technologies involved in the Portable Task Luminaire. This report covers the activities of this program as amended, and includes the development and fabrication of all of the systems. This report constitutes the final fulfillment of the contract.

Jan 1, 1974

By M. Karmis

Surface subsidence is an inevitable consequence of many underground mining operations and has been recognized as such since the fifteenth century. Damage resulting from this phenomenon ranges from simple land settlement to severe structural damage to buildings and has been witnessed in rural (Illinois, Colorado, West Virginia, Virginia, Pennsylvania) as well as in urban areas (Pennsylvania, West Virginia, Illinois, Wyoming). In fact, it is estimated that over 2 million acres of land across the United States have been affected by mining subsidence, of which 140,000 acres are in urban areas (Singh, 1978; Johnson and Miller, 1979). Further, it is estimated that during the next twenty years an additional 1.5 to 2.4 million acres of land will also be affected by mining. Subsidence prevention is not feasible, at least under the existing technologic and economic constraints of underground coal mining. Foreign experience has demonstrated, however, that subsidence can be successfully controlled if an accurate method of predicting ground movements is available. Such techniques have been developed in many coalfields, where it is currently accepted that subsidence can be predicted within ± 20 percent of the actual values. Furthermore, such movements can be translated into anticipated structural failures using established damage criteria, thus enabling appropriate precautionary measures to be implemented.

Jan 1, 1983

In the interest of safety in underground coal mining, the Bureau of Mines recommends: 1. That doors used to control ventilation (a) Shall be installed in pairs to form air locks, (b) Shall be self-closing, (c) Shall not have latches or other devices for holding them open, (d) Shall be constructed and maintained to prevent excessive air leakage through or around them, (e) Shall be fire resistant. 2. That wherever practicable the use of doors shall be limited to development openings. The Mine Safety Board is of the opinion that the best practice in coal-mine ventilation makes use of a split system employing overcasts or undercasts with doors limited as far as feasible to development openings. The distance between air-lock doors on haulageways should be sufficient to accommodate a trip or train of maximum length. Where auxiliary doors are installed to control ventilation during emergencies, they should be so placed that they can be utilized readily in case of damage to the air-lock doors.

Jan 1, 1938

By L. C. IlsLey

"During the last eight years there has been a noticeable increase in the use of permissible equipment in gassy and dusty coal mines. This trend has undoubtedly been toward greater safety in mining, but in spite of this all is not well ""along the front.""In many mines those in charge, either through ignorance or supposed economy, have neglected to install sufficient copper and maintain good bonding on the rails used for return circuits to have a safe working voltage for the permissible equipment which is intended to afford them safety.Low voltage, when properly analyzed, is not economy but frequently is an expensive oversight. Burned-out armatures, controllers, rheostats, and switches are costly in themselves to repair or replace, but the greatest cost in many instances is the loss of production resulting from idle and broken-down equipment.From a safety standpoint, excessive low voltage where permissible equipment is necessary is almost criminal negligence. A burn-out of any kind is liable to cause an arc that may burn its way through a casing wall and bring about a hazardous condition if gas or dust in explosive proportions should be present. Again, all wiring, both interior and exterior to the apparatus, is subject to the extra heating consequent upon low voltage. It should be remembered that if the voltage drops the current must increase a corresponding amount in order that the same work may be accomplished; and as the heating effect is as the square of the current, an enormous overheating of the electrical parts and wiring often takes place. This heating effect is especially detrimental to trailing cables used on portable equipment, because under the most favorable conditions the size of cable selected is only barely sufficient to do its work properly at a safe working temperature; therefore, when the extra current load is added because of poor voltage, overheating is sure to result, with consequent deterioration of the insulation, This effect greatly increases the liability of cable failures in service, and in turn adds to the hazards incident to the use of portable equipment of the permissible type involving the use of trailing cables.Some manufacturers have tried -to protect their equipment from low voltage, especially below a certain point, by -installing low-voltage relays which will trip when the voltage falls to a predetermined value. It is understood that some operators have hesitated or refused to install such low-voltage protection because they were aware that the voltage conditions were so poor that the equipment could not operate under the safe limits set. It is difficult to understand how any progressive company that is willing to go to the ex-pense of installing permissible equipment could be so shortsighted in this phase of common sense, safety, and economy."

Dec 1, 1929

By E. D. Gardner

"Trolley lines used in connection with electric haulage in mines are a source of danger and many lives have been lost by men accidentally coming in contact with the wires. Usually the wires in metal mines are sufficiently guarded to prevent men from touching them with their person or by pieces of steel which they may be carrying or their shoulders, while walking along the level. However, it is difficult to guard effectively the wires at loading chutes along the haulage ways and in spite of safe guards, chute tappers have been electrocuted through loading bars accidentally touching the trolley line.To overcome this danger the Calumet & Arizona Mining Co., at Lowell, Arizona formely used a hinged V-shaped trough made of 1-inch by 6-inch lumber, that was dropped over the wire in front of the chute, when the cars were being loaded. This arrangement interfered with the easy operation of the chute, and a cut-out device for the trolley line was devised by W. R. Gibson, chief electrician for the company. This cut-out is efficient easily constructed and roes not interfere with the operations at the chutes or with the motors operating on the same level.When the cut-out is open the electric current is carried past the gap by an insulated wire on the opposite side of the drift. A hinged board drops down over the ends of the trolley guard when the slide is open and Prevents anything touching the live wires. About ninety of these cut-outs are now in use in the mine,The levels under the scopes are timbered with drift sets placed 5 feet apart, and the loading chutes take up the space between two sets. All trolley wires in. the company's mines are carried 6 feet above the rails and guarded by two 1/2 by 6-inch boards placed on either side of the wire."

May 1, 1921

By Sean Gallagher

This report describes research by the Bureau of Mines on alternative materials-handling strategies for reducing the costs and incidence of back injuries in low-seam coal mines. Strategies recommended for redesigning materials-handling tasks include elimination of tasks, mechanization of tasks, and matching lifting tasks to the physical capabilities of underground miners. The report also discusses other methods that can be used by management to reduce the costs associated with back injuries.

Jan 1, 1989

By Raymond B. Ladoo

The uses for which ground talcs are suited closely depend upon their physical and chemical properties , but , in spite of this fact , little scientific investigation has been made in order to devise quick and accurate tests for the determination of these properties . The chemical properties of talc are inherent and may not be altered or modified except by selective mining or by chemical processes not practical in the present status of the industry . However , the determination of chemical properties is not so important , for most uses , as of physical properties , although sometimes certain chemical characteristics are perhaps unduly insisted upon by chemists in some industries . Physical properties are dependent both upon mineralogical characteristics and upon methods of grinding and sizing and may thus be partly changed or modified by changes in practice . There is so little known of the chemistry and physics of the various processes in which talc is used that the purchase and sale of talc is governed more by rule- of- thumb methods dependent upon individual opinion and often , prejudice , than by accurate , standard tests . This not only causes unwarranted price fluctuations , but injures both the producing and consuming industries by creating false ideas of the suitability of talc for various uses . It thus seems important that present tests be standardized and made uniform for the whole industry , and that new tests devised to fill the existing gaps .

Jul 1, 1920