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By O. M. Schaus

This paper is one of a series, prepared by the Bureau of Mines and deals with the Montreal mine, one of only two active properties in Wisconsin on the Penokee-Gogebic range. The purpose of this paper is to describe the conditions of occurrence of iron ore in a particular property and to present sufficient details of equipment and production methods to convey to the unacquainted operator a correct idea of the mining practice.

Jan 1, 1930

By Jerry E. Olson

In 1986, at the request of the U.S. Bureau of Land Management, the U.S. Bureau of Mines studied part of the 20,071-acre South Fork Wilderness Study Area (OR-005-033) and part of the 8,791-acre Sand Hollow Wilderness Study Area (OR-005-034) in order to evaluate their identified mineral resources. The study areas are located in Crook County, OR, about 58 air miles east from Bend. The areas studied are underlain by Tertiary- and Quaternary-age volcanic and tuffaceous sedimentary rocks. No mineral resources were identified in or adjacent to the study area. Except for common opal and agate occurrences along the northern boundary of the study areas, no mines, prospects, or mineralized zones occur within the study areas. Bentonite is periodically mined less than 1 mi southwest of the Sand Hollow study area boundary. Neither of the study areas has geothermal leases, but both areas are under lease for oil and gas.

Jan 1, 1987

By C. O. Karacan

Underground longwall mining of coal causes large scale disturbance of the surrounding rock mass. The disturbance can increase the rock mass permeability through a reduction on the stress as well as formation of new fractures in the rock. Methane gas contained in the disturbed rock mass can migrate towards the low pressure mine workings and present an explosion hazard. This paper describes the application of a finite difference program to develop a geomechanical model that predicts permeability changes within the rock mass. The calculated permeabilities are used as input to a reservoir simulator that models methane desorption from the coal matrix, methane release from the rock layers and flow towards the mine excavations. The model also considers the basic characteristics of the mine ventilation network. The geomechanical model uses empirical relationships between fracture permeability and stress to calculate permeability changes around a longwall face. The extent of rock failure is determined using a strain softening model that considers both rock matrix and bedding plane failure. The cave rock (gob) is modeled as a compressible, granulated material. The calculated horizontal and vertical permeabilities around the longwall face are averaged and used as one of the inputs to the reservoir model. The reservoir model was developed and calibrated against records of methane flow at a study mine in southwestern Pennsylvania. Good correlation between actual gas production and model outputs has been achieved. The modeling approach provides a basis for estimating methane inflow and optimizing control measures.

"INTRODUCTION These inspection standards have been prepared for use as a guide for the Federal inspection of anthracite mines. They are a revision of ""Tentative Inspection Standards for Anthracite Mines,"" published as Bureau of Mines Information Circular 7231 in January 1943 and used as a guide for Federal inspections. Numerous changes in the original standards have been made, due in part to recognition of shortages of some types of safety equipment due to the war, in part to need of additional standards to cover certain mine conditions and practices, and in part to conditions not foreseen when the original standards were prepared.Throughout these standards reference is made to determining the methane content of the mine air by using a permissible flame safety lamp. The Bureau has approved various electrical devices for the detection of methane, but it is recognized that new devices for determining the percentage of combustible gases as well as the percentage of oxygen, might be perfected for general use in mines, and therefore it may be necessary to revise certain standards to include the use of such equipment if and when the device is accepted as being permissible.About one-fourth of these standards are marked with an asterisk (*) as being of particular importance in preventing accidents in many coal mines; however, failure to carry out the suggestions made in such of the other standards as are applicable may also lead to loss of life.With continuing change in mining methods, some of these standards may become inapplicable, and further revision will be advisable. Therefore, question regarding these standards and suggestions regarding new standards should be brought to the attention of the Bureau, so that changes may be made from time to time. Numerous changes proposed by mine operators and by State mining departments have been incorporated in these standards."

May 1, 1944

By E. K. Stanek

This report contains results of two major efforts related to electrical transients on mine electrical power systems. The first area concerns the use of digital computers to model mine electrical power systems and predict transients or duplicate field recordings of transients. Two existing general purpose circuit analysis programs were used. The first was the TRW Engineering System Simulator or TESS. The second was Electronic Circuit Analysis Program or ECAP. TESS proved to be superior to ECAP in several important characteristics, including system size limitations and modeling nonlinear elements. The second major topic covered in this report is the evaluation of commercially available surge suppression devices. These devices were found to be quite acceptable and guidelines for the selection and placement of surge suppressors were included. The final important item is a listing of the worst-case transients, from a design point of view, for ac and de utilization systems and ac distribution systems.

Jan 1, 1979

By A. Erickson

The effectiveness of a loader-mounted fan on diesel vehicles combined with natural convection for ventilation of a dead heading (the patented Janelid system) was investigated experimentally. The results were obtained using CO2 as a tracer gas in a 1/4 scale model heading. Buoyant forces were scaled to establish similarity with full scale. For a loader moving in a typical load-haul-dump cycle, the loader-mounted fan reduced the tracer gas concentration by 26 percent compared with a reduction of 32 percent for a jet fan of four times the flow capacity.

Jan 1, 1981

By G. B. Shea

In the search for possible future sources of petroleum products, the recovery and utilization of bitumens from the large outcropping deposits of bituminous sandstones in the United States have been under study by the Bureau of Mines for the past several years. The results of laboratory research in the adaptation of the hot-water separation process to recovery of bitumen from bituminous sandstones were reported in an earlier publication, on the Edna deposits near San Luis Obispo, Calif. This publication included analytical data on the cracked products and asphalts obtained from the extracted bitumen and on the cracking and distillation of the bitumen. Comparable hot-water separation tests have been run in the San Francisco, Calif., laboratory of the Bureau of Mines on quarry samples from the large deposits of bituminous sandstones near Vernal and Sunnyside, Utah. The bitumens were isolated from the extracts of the separation plant and analyzed at the Petroleum and Oil-Shale Experiment Station of the Bureau of Mines, Laramie, Wyo. Part I of this report summarizes the general characteristics of the Vernal and Sunnyside deposits and discusses the hot-water separation process as applied to those bituminous sandstones and the results obtained. The separation tests showed that these bituminous sandstones also respond to treatment by the hotwater method of separation. The bitumen in the Vernal sandstone was extracted more readily by the action of hot water than was the Edna bitumen, which greatly simplified plant operation. The Vernal sandstone contains no water-soluble iron compounds, such as were found in the Edna sandstone, and, therefore, required no preliminary water washing. Recovery of bitumen from the Vernal sandstone was about 96 percent.

Jan 1, 1952

By Robert L. Virta

This U.S. Bureau of Mines paper discusses the structure of the talc industry, talc production, processing of talc ore, applications and demand for talc, and the outlook for the talc industry.

Jan 1, 1989

By Pedro Lilienfeld

This report describes the development, design, fabrication and testing of a port-able, battery-operated, light scattering monitor (henceforth to be designated as ILSDM) for the rapid measurement of the concentration of respirable dust in mining environments. This instrument incorporates state-of-the-art design characteristics and makes use of advanced solid-state components both for light emission as well as for its detection. The use of a pulsed light source combined with synchronous signal detection minimizes drift problems and optimizes the sensitivity of the measurement. Simplicity of operation, reliability and ruggedness, light weight as well as improved performance were salient objectives of this instrument development program. Continuous clean-air flow screening of all critical optical surfaces, and optimized optical detection and electronic signal processing design resulted in about a hundred-fold decrease of noise and drift with respect to precursor instruments. Equivalent mass concentration measurements 88 low as 10 micrograms per cubic meter can be routinely performed with time constants of about 2 second.

Jan 1, 1979

By Donald C. Strimbeck

The Bureau of Mines designed a down-fired refractory-lined combustor that efficiently burned pulverized coal to produce a gas suitable as working fluid for an open-cycle gas turbine. The gas contained relatively little carbon, so the load on the ash-separation equipment was significantly reduced. Moreover, reduction in carbon content of the gas increased the average density of the solid particles making them more amenable to removal by centrifugation. Centrifugal-type separators failed to remove sufficient ash; however, to limit blade wear enough to achieve operating periods generally deemed necessary for commercial practicability.

Jan 1, 1969

By Ronald M. Lewis

Quadratic functions, Q(hkl), are given to six places in increments of 0.01° for 2? from 00 to 90° for FeKa and from 25° to 180° for FeKa1. The wavelengths used for Fe in the computation are those agreed upon by the Editorial Commission of the International Tables for X-ray Crystallography (1950): FeKa1 1.93597 A.; Feka2 1.93991 A. INTRODUCTION At the Federal Bureau of Mines laboratory, Norris, Tenn. X-ray diffraction crystallography using tubes with iron targets revealed a need for a handy reference for the quadratic functions of iron radiation. The tables presented here were prepared to satisfy that need. The quadratic form Q(hkl) may be expressed in terms of the Bragg diffraction angle 2? and of the wavelength ? as

Jan 1, 1961

By W. L. Heidenreich

This report describes the methods and results of field investigations conducted by the Bureau of Mines between December 1956 and December 1957 on seven deposits of nickel-cobalt-iron-bearing laterite and weathered serpentine near the west coast of Puerto Rico east and south of Mayaguez. These deposits were named, for purposes of identification, Guanajibo, Punta Guanajibo, Las Mesas, north and south deposits of the Rosario Southeast group, and the west and east deposits of the Maricao Southwest group. In addition, the lower 17 miles of the Guanajibo River Valley was tested at widely spaced intervals for possible concentrations of magnetite and chromite in the alluvial sands. The objective of the investigations was to appraise, by drilling and sampling, the two largest deposits--the Guanajibo and Las Mesas. Testing of the smaller deposits was much more restricted. Field investigations consisted of mapping, drilling with power auger, sampling drill-hole sections, and pre-paring samples for chemical analyses, mineralogical studies, and metallurgical tests. The work was financed jointly under a cooperative agreement by the Bureau of Mines and the Economic Development Administration, an agency of the Puerto Rican Commonwealth.

Jan 1, 1959

By Ed D. Thimons, Douglas E. Pollock, Andrew B. Cecala, Gregory J. Chekan, Jay F. Colinet, John A. Organiscak

Researchers at the Pittsburgh Research Laboratory (PRL) of the National Institute for Occupational Safety and Health (NIOSH) work to reduce respirable dust exposures in mining operations. One focus of this research is silica dust control for surface and underground operations in the metal/nonmetal mining industry. PRL researchers analyze dust sampling results from the Mine Safety and Health Administration (MSHA) to identify high-risk occupations to guide research efforts. Research is then conducted in an effort to improve existing technologies and/or develop new controls for reducing worker exposure to airborne silica dust. During the last few years, PRL researchers have conducted research related to the following goals: improving protection provided by enclosed cabs on mobile surface mining equipment, reducing dust generation from surface drills, reducing dust levels in iron ore operations, and developing a new method to clean dust from workers’ soiled clothes. A description of each of these controls and subsequent dust reductions quantified through site surveys will be provided.

By John C. Machisak

THIS CHAPTER of the Minerals Yearbook (volume III) contains overall injury experience and employment data at bituminous-coal, lignite, and anthracite mines, coking plants, metal and nonmetal mines, metallurgical plants, and stone quarries in the United States for the calendar year 1956. Volume I of the Yearbook includes injury experiences and related employment data in the metal, nonmetal, and quarrying industries, and in the milling operations connected with the mining of those commodities. Volume II contains the injury and related employment experience of the coal mining, coking, and oil and gas industries. Reporting is voluntary on the surveys conducted by the Bureau of Mines to collect injury and employment data in the mineral industries, except in the coal-mining industry, where operators are required by Federal law to furnish the information requested.

Jan 1, 1958

By W. W. Adams

"The seventh National Safety Competition, that for 1931, conducted by the United States Bureau of Mines, was participated in by 350 mines and quarries operating in 34 States. Tables 1 to 5 show the relative standing of the various plants, Bronze trophies, known as the ""Sentinels of Safety,"" which were provided by The Explosives Engineer magazine to be awarded annually by the Bureau of Mines were awarded to five companies, each company having established the best accident—prevention record within one of the five classes into which all companies were divided — namely, anthracite mining companies, bituminous—coal mining companies, metal—mining companies, operators of nonmetallic mineral mines other than coal mines, and quarries or open—cut mines. The trophies are awarded for one year and are then transferred to the winners of the succeeding year's contest.The outstanding feature of the contest of 1931 was the operation of a bituminous coal mine without a lost—time injury to any employee. While accident—tree records had previously been made by certain quarries, metal mines, and nonmetallic mineral mines, never before has such a feat been accomplished by a bituminous coal mine in the National Safety Competition. Whether or not such a record has been made by a bituminous—coal mining company not enrolled is the competition the writer does not know, but it is believed that the case referred to is unique among large coal—mining companies. The mine to which reference is made is No. 1 mine of the Phelps Dodge Corporation, at Dawson, N. Mex. To that company belongs the distinction not only of being the first coal—mining company among those enrolled in these yearly safety contents to operate its mine without an accident but also of occasioning the 'Sentinels of Safety' trophy for a bituminous mine to take its first journey west of the Mississippi River. For the past six years the trophy has been in West Virginia, Alabama, or Pennsylvania."

Jun 1, 1932

By Todd M. Ruff

The majority of fatalities that occur in road construction work zones in the United States involve a worker being struck by a piece of construction equipment or other vehicle. The Spokane Research Laboratory of the National Institute for Occupational Safety and Health, in cooperation with the Washington State Department of Transportation, is evaluating methods to decrease these accidents. One such method uses devices that assist equipment operators in monitoring blind areas around the equipment to prevent collisions with workers on foot or other objects. Several cameras and sensor systems are available for this application, and a study was conducted to evaluate these systems on various trucks used in road construction and maintenance. Tests were conducted using sanding trucks during the winter months, which allowed researchers to investigate the effectiveness and limitations of various technologies under the most extreme conditions. Tests were also conducted using dump trucks during the warmer months to study the effectiveness of the systems in highway work zones. Results show that many difficulties arise when using camera and sensor systems in cold, snowy climates. And, while the operation of these systems is more reliable during the warmer months, challenges still exist in using them on equipment in crowded work areas.

Jan 1, 2004

By R. Karl Zipf, Z. T. Bieniawski

"Fracture mechanics plays an important role in studies of geologic materials such as rock and coal. Yet fracture data are scarce for rock and most limited or unreliable for coal. A testing system was developed which can apply mixed mode loads to a crack tip in many rocks and geologic materials. It is possible to subject the test specimen to pure mode I, various mixed modes and a nearly pure mode II fracture load. The system is currently used to study the mechanics of fine fragment formation in various coals. Experimental measurements include KI and KII' fracture velocity and acoustic emission.INTRODUCTIONA major research program at The Pennsylvania State University is directed to understanding the fundamental mechanics of fine fragment formation in various coals. The program represents an effort to reduce the incidence of coal workers pneumoconiosis (black lung) in coal miners. The principal source of the respirable coal fragments is the cutting operation which forms and liberates the particles by a fracture process. Present understanding of the mechanics of the events which form and liberate these particles is meager (Cook, 1982).Current knowledge of the fundamental mechanisms of coal dust generation and entrainment in terms of the underlying fracture mechanics is critically needed to improve and possibly control the processes involved. Whether the cutting operation is done with a 'continuous miner' cutting machine, a plow or a longwall shearer, it is fundamentally a problem of mixed-mode crack propagation. When a cutting tool interacts with coal, it causes numerous cracks to propagate through the intact material. Numerous larger fragments are broken free, but another quantity of undesirable fine fragments is also created. The formation of these respirable fragments may be a direct result of the crack propagation process; hence, a thorough understanding of the fracture mechanics of coal is required to minimize production of the unwanted fine fragments.In most rock engineering applications, the rock material properties are of secondary importance to the rock mass properties; however, for rock fragmentation and rock cutting problems, it is rock material properties such as fracture toughness which are of prime interest (Bieniawski, 1980). Several rock cutting and rock failure theories have been proposed, but it is only very recently that fracture mechanics concepts have been successfully applied to the study of rock cutting mechanics. All cutting models seek to predict the cutting forces and the cutter geometry necessary to cause rock breakage and chip formation given some fundamental mechanical properties ~f the rock. Such models have wide applications in drilling, tunnel boring and mining problems. Nelson et al., (1985, 1986) has provided a very useful correlation between the laboratory measured fracture mechanics properties of rock and the performance of the disk cutters on tunnel boring machines."

Jan 1, 1989

By F. Fraas, J. E. Conley

"The problem of recovering potash from the mineral polyhalite (K2SO4.MgSO4.2CaSO4.2H2O), occurring in large quantities in the salt beds of Texas and New Mexico, has been under investigation at the Nonmetallic Minerals Experiment Station of the U. S. Bureau of Mines continuously since 1928. Most of the results previously obtained have been published in technical journals and in a series of Bureau of Mines Reports of Investigations.The experiments described in the present report were performed to ascertain whether a continuous countercurrent extraction of calcined polyhalite by hot water would yield satisfactory recoveries and concentrations of sium sulphate in the top liquor. Previous investigation by Storch 4 had shown that the rate of solution of uncalcined polyhalite was too slow to be of value in an industrial process, and Storch and Clarke 5 had demonstrated that calcination of the polyhalite greatly, accelerated the rate of solution in hot water, allowing most of the potassium sulphate to be readily extracted."

Sep 1, 1933

By H. D. BAILEY, John W. Cole

This paper is one of a series on mining methods and costs published by the Bureau of Mines .. Because of the role, played by the Federal Government in the discovery of the ore body, a description of the exploratory operations of the Bureau of Mines, is included ...

Apr 1, 1948

By R. J. Matetic, David S. Yantek, David K. Ingram

The National Institute for Occupational Safety and Health (NIOSH) has investigated engineering noise controls to reduce sound levels in cabs on air-rotary drill rigs. A recent investigation revealed that some drillers are exposed to A-weighted sound levels exceeding 85 dB even though a cab is used. NIOSH studied the in-cab sound levels of one such rig. First, preliminary tests were conducted in a controlled environment using accelerometers and microphones with spectral analysis to identify the dominant noise sources for in-cab sound levels. The results indicate that vibration transmitted from multiple hydraulic pumps to the control panel produces a dominant spike in the sound level spectrum in the 400 Hz 1/3-octave band. Next, field tests were performed in a production environment to evaluate noise controls to reduce in-cab sound levels. It was found that utilizing hydraulic noise suppressors reduces the structure-borne noise transmitted to the control panel. Further, using hydraulic noise suppressors and enhancing soundproofing reduced the in-cab A-weighted sound levels by as much as 4 dB.