Search Documents

By R. L. Brown

This report is the 18th in a series summarizing Bureau of Mines research and technologic work on coal and related investigations. The previous 17 reports have covered fiscal years, but this report covers not only the fiscal year from July 1, 1952, to June 30, 1953, but also July through December 1953, to bring the report to a calendar-year basis. Most of the material in this report relates to publications issued during the reporting period, Some work is mentioned briefly on which publications have not yet been issued or on which data are riot expected to be published, for security or other reasons, and in a few instances publications issues before the reporting period but not included in the previous report are mentioned.3/ Further details on the published work described herein may be found by referring to the publications cited in the footnotes. During the reporting period, the Bureau directed its research and technologic work on coal toward developing end encouraging increased conservation and more efficient use of our mineral fuel resources through more efficient and safer mining methods and improved methods of preparing and utilizing these fuels. Some significant advances, particularly in coal-mine safety, mining methods, and development and utilization of low-rank coma have been made.

Jan 1, 1954

By Janine Pierce, Robert Larson, Christine Raasch

The vibration and impact environment for crew members on locomotives has been investigated in a series of studies conducted by Exponent Failure Analysis Associates (Exponent) beginning in 1990. Locomotive cab vibration and impact levels were measured on a variety of locomotive models operating over many different track sections across the Union Pacific, Burlington Northern Santa Fe, CSX, Norfolk Southern, and CONRAIL systems. The comfort and health implications of exposure to the measured locomotive vibration levels were evaluated by comparison with the human vibration exposure boundaries given in the International Standards Organization (ISO) standard 2631-1:1997, the British Standard 6841:1987, European Union (EU) Directive 2002/44/EC, measurements made by Exponent on various commercial and recreational vehicles, and vibration exposure measurement data found in the literature. Methods Initially, vibration levels experienced by locomotive crews were measured and recorded at incremental speeds covering the range of normal train operation. In 2003, a method of measuring the vibration exposure continuously by means of a digital recorder was developed, allowing the vibration level over the entire run or crew shift to be analyzed. For each seating location measured, acceleration was recorded on the seat surface beneath the ischial tuberosities (pelvis) of the seated crew member and on the cab floor directly under the seat. At each of the locations, triaxial accelerometers were used to measure the vibration along the longitudinal, lateral, and vertical axes. Since the vibration environment varies throughout the route, and locomotive vibration levels have been found to be primarily speed dependent, a speed sensor was used to continuously measure the speed of the train. To evaluate the recorded vibrations levels, the data was divided into two-minute segments, which were each processed per the 1997 ISO standard for weighted RMS vibration levels and Vibration Dose Values (VDV). Additionally, PSDs and 1/3 Octave RMS values were calculated to determine the frequency content of the vibration. For each two-minute segment, the average speed of the locomotive was calculated to allow for correlation with the recorded vibration exposure values. The resulting exposure values for the entire run were calculated by combining the data from all of the two-minute segments. Since introducing the continuous method of recording acceleration, 23 seating locations have been recorded on 11 locomotives traveling 11 different routes across various parts of the United States. One of the routes was a shift of ‘yard work’, traveling back and forth in a rail yard coupling train cars together. Results A guide to interpreting weighted acceleration values with respect to health is given in Annex B of the 1997 ISO standard. A health guidance caution zone is defined to indicate the

Jan 6, 2006

By C. H. Schack, A. O. Ipsen, H. G. Poole

"INTRODUCTION In the course of the investigation of manganese mineral occurrences in continental United States, the Bureau of Mines has collected several lots of ore from properties in the vicinity of Long Valley, Ariz. The ore occurs as irregular and random pockets in a brecciated zone. As only high-grade portions of the deposits obtained by selective mining would be acceptable as commercial-grade manganese ores, an investigation was made to determine amenability of the ores to concentration by ore-dressing methods. Several types of ores, differing in grade and mineral associations, were studied.Ores from the Vaiazza property are of special interest, owing to the successful application of silica flotation for their concentration. Ores from the Shroup and Conner-Hough properties are very similar but differ somewhat in their response to ore-dressing Method's. In all instances, the man¬ganese minerals are psilomelane and pyrolusite, with minor amounts of other manganese oxides. The country rook is a brecciated limestone; the diluent in the high-grade ore pockets is chiefly silica. The low-grade manganese ores are limestone replacements, and the chief gangue material, of course, is limestone."

Nov 1, 1947

The overall objective of this study is to gather operational data from selected surface coal mining systems in the United States, and to assess the potential production and economic capacity of the systems. The study includes: four mines, each using a different mining technique and different equipment. One mine was selected from each of the major coal fields: Midwestern, eastern,, northwestern, and southwestern. The Midwestern Mine is located in the Central Plains and produced 1.45 million tons of raw coal during the study year The Midwestern Mine uses the area mining or box-cut technique. A large in-pit shovel and a bucket wheel excavator are used to remove the overburden. Coal is removed by a loading shovel and transported to the dumping point by large off--highway trucks.

Jan 1, 1975

By Brian G. White

The Coeur d'Alene Mining District of northern Idaho is remarkable for its number of large ore bodies and for the amount of its historical production of lead, zinc and silver (Fig. 1). Since veins were first discovered in 1884, more than 127 Mt (140 million st) of ore have been produced from narrow, high-grade veins. Mining continues at the Lucky Friday, Galena and Sunshine mines (Fig. 2). All have been in production for decades. At these mines, more efficient mining and exploration techniques have reduced costs while adding significant new reserves. Even the old Bunker Hill Mine, where ore was first found in 1875, continues operation on a limited basis, partly involving production of world-class pyromorphite specimens. Until recently, the Coeur Mine was also a profitable silver producer. Other large producers have included the Star-Morning, Hecla, Page, Standard-Mammoth, Hercules and Gold Hunter mines (Fig. 2). The first deposits were discovered by prospectors who spilled over from the Murray gold mining district, 24 km (15 miles) to the north. The Bunker Hill Mine was founded the year after the first veins were discovered. Bunker Hill has now operated for more than 100 years. Production includes 2.3 Mt (2.6 million st) of lead, 1.1 Mt (1.2 million st) of zinc and 4.1 kt (132 million oz) of silver. Total district production through 1996 (Springer, 1997) amounted to 7.3 Mt (8.1 million st) of lead, 3 Mt (3.3 million st) of zinc, and 34.5 kt (1.109 billion oz) of silver. This record establishes the district as the largest recorded producer of silver in the world, while also yielding major quantities of lead and zinc. Only Potosi, Bolivia, may have produced more silver, although records are unclear. Despite the district's longevity, historic production and current activity, the published literature on the district lags behind with regard to recent concepts of district geology. The most recent comprehensive US Geological Survey (USGS) bulletins (Hobbs et al., 1965; Fryklund, 1964) are dated. Much research in the last half century has been short-lived or geographically restricted because the district is large and its geology is complex - and even this research tends to remain unpublished. Thus, it has been difficult for in- [ ]

By Robert W. Freedman

The Bureau of Mines investigated methods of analysis of free silica in respirable dust, including both work done at the Bureau of Mines and work done elsewhere. The review covers both coal dust and noncoal dust, taking into account both existing and proposed chemical and spectroscopic procedures.

Jan 1, 1971

By R. A. Egen

The purpose of this book is to provide an indication of what good hoisting practice is and how it might be achieved. To this end the book contains discussions of equipment and inspection and maintenance procedures developed and used by mining people in striving for safe, reliable hoisting equipment. Most of this information comes from domestic practice; the rest is foreign, notably from Canada. Most things discussed have long proved their general worth, and others promise to; a few are beginnings. However, nothing is conjectural or theoretical; the practices described herein are in use somewhere in the mining world. The stress is on equipment in use; it is not a design-guidelines manual. Nevertheless, there are some sections dealing with design material since it may be of value in a maintenance/ replacement sense. Mine hoisting installations encompass such a wide variety of equipment and conditions that it is impractical to specifically cover them all. This book mainly treats conventional systems using conventional components with some discussion of the more common unconventional (special) systems in use. There is no recognized definition for a "conventional" mine-hoisting system. Herein the term means those systems most commonly used in daily operations for transporting men, materials, and product-electrically driven drum and friction hoists, with guided conveyances running in vertical or inclined shafts. Beyond this, what "conventional" means is probably best illustrated by the topics discussed.

Jan 1, 1975

By L. H. Banning

Recent dry-top electric smelting tests at the Northwest Electrodevelopment Experiment Station, Albany, Oreg., indicate that a high-titanium slag and a good grade of pig iron can be produced from alluvial Idaho ilmenite. A total of 120 tons of concentrates were smelted during this investigation, to yield an average of 0.5 ton of slag and 0.3 ton of pig iron per ton of ilmenite. Power consumption averaged 1,400 kv.-hr. per ton of ilmenite, at a feed rate of 400 to 500 pounds per hour, when operating at an electrical energy input of 290 to 370 kilowatts. The optimum operating voltage appeared to be 110 volts, phase-to-phase. Graphite electrode consumption averaged 15.6 pounds per ton of ilmenite smelted. Magnesite furnace refractory withstood the corrosive action of the hot metal and slag better than carbon refractory.

Jan 1, 1955

By William E. Eckard

Production of oil from a narrow shoestring sand presents problems unique in the oil industry. Especially important, from both an engineering end an economic standpoint, are the limitations imposed upon well patterns and spacings by the shape of the field. This report concerns a study of the Paola shoestring, Miami and Franklin Counties, Kane., where well density of 0.85 acre per well was not uncommon to insure profitable primary recovery in a reasonable time. However, such a great number of wells increased the operator's investment and reduced his profit considerably. It was the purpose of this study to investigate various well patterns and spacings applicable to water-flooding a shoestring reservoir and the effect of these factors upon recovery of oil and the most profitable operation of the pool. The designer of well patterns for a shoestring sand should evaluate carefully the edges of the shoestring, even though they may be considered too thin to drill. These comparatively thin edges contain large quantities of recoverable oil; moreover they are resaturated with oil as the pool is water-flooded.

Jan 1, 1951

By L. Allan White

Instrumental analysis is an indispensable tool to many phases of research on rare-earth metals and their compounds; therefore, the development of new and improved instrumental techniques is essential. This report describes an emission spectrometric analytical method using direct-current carbon-arc excitation of various rare-earth-oxide mixtures. Lanthanum oxide serves the dual purpose of an internal standard and a constant major constituent. The versatility of the method was demonstrated by three different applications: (a) Analysis of complex rare-earth concentrates; (b) determination of impurities in high-purity rare-earth oxides; and (c) detection of rare-earth elements in other types of matrices, such as those resulting from beneficiation of rare-earth ores. The average error of analysis in the concentration range of 0.2 to 10.0 percent was 14.6 percent for a group of complex synthetic mixtures of rare-earth oxides. An average error of analysis in the concentration range of 0.05 to 0.50 percent was 21 percent for a group of high-purity rare-earth oxides.

Jan 1, 1959

By R. V. Ramani, J. M. Mutmansky, J. Qin, J. Organiscak, R. Bhaskar

"The results of a two—year research study into the relationship between quartz dust levels in host material and in respirable dust in continuous mining sections are presented in this paper. The experimental design and sampling procedures for underground data collection are outlined. The sample analysis procedures for quartz determination, the ¬analysis results and conclusions of the study are discussed.The results of the study indicate that the quartz contents of the airborne dusts are generally higher than those in the host material and bulk samples; and the quartz content increases with decreasing size of the airborne dust. The source for quartz appears to be the roof and the floor materials rather than the coal seam itself. It also appears that the material containing quartz may be breaking into a different size distribution than coal.INTRODUCTION Without doubt, the potential for permanent and severe health damage exists due to respirable dust in the work environment. The attention directed at the reduction of respirable airborne dust to levels below those specified in the law and the achievements to date in meeting these standards are but a reflection of the recognition by many parties government, industry, and labor - of this potential and the need to reduce it.The ambient dust standard in underground U.S. coal mines (2 mg/s3) has a qualifier (Code of Federal Regulations, Title 30, Part 71.101) to determine an applicable dust standard when a respirable dust sample contains more than 5% quartz. This standard is frequently referred to as the ""reduced standard."" The reasoning behind the reduced standard is the relative toxicity of the quartz dust compared to that of pure coal dust. As the quartz levels in samples increase, the applicable standards become more stringent and maintaining the workings in compliance becomes increasingly difficult.The number of underground work locations operating under the reduced standards has shown a dramatic increase since 1980 (Figure 1). For comparison purposes, there were no mining entities operating on reduced standards prior to 1977. The emergence of this problem, which affects the health and safety standards on one hand and creates severe compliance problems on the other, has been rapid."

Jan 1, 1990

By C. C. Merrill

Studies were made to determine the amenability of yttrium to fused-salt electrorefining in a controlled atmosphere. Tests were conducted in a LiCl- YCl3 electrolyte system at 710° C. The major variables studied were the YCl3 content of the electrolyte, from l.7 to 13.4 mol percent, and the initial cathode current density, from 410 to 1,630 amperes per square foot. Vacuum distillation was employed to remove salt from the deposited metal. Metallic impurities, except for lithium, could be reduced to near or below their lower analytical limits, ranging from 10 ppm for Cu to 300 ppm for Ta; reduction of oxygen content, however, was accomplished only in metal produced from electrolytes with 5.4 mol percent YCl3 or less. Initial cathode current density had little effect on the purity of the product.

Jan 1, 1967

By S. J. Gasior

Pilot plant studies showed the technical feasibility of fluidized-bed operation for producing hydrogen and synthesis gas by the steam-iron process. A mixture of iron and iron oxide from 20-to 100-mesh was partially reduced with a simulated producer gas and then oxidized with steam and/or carbon dioxide. Results of tests show the effects of pressure, temperature, bed height, gas-to-solids ratio, type of iron oxide, and composition of gas on the gas and solids conversions during reduction and oxidation. A baffled free-fall solids system was also found operable. The short residence time of about 5 seconds limited conversion of the solids.

Jan 1, 1961

By M. C. Malamphy

A general description of the activities and results of bauxite investigation by the Bureau of Mines at its bauxite project in Saline and Pulaski County, Ark., has been given in Report of Investigations 4251. The factual data obtained during the project are reported in a series of Reports of Investigations beginning with No. 4251, of which this is the eighth. The data are accompanied by maps showing the location of holes drilled and the deposits developed. Each area upon which work was done is reported by half townships. Each bauxite deposit investigated was assigned a name and a number for ready reference and identification, and its location and name are shown on the appropriate half-township map. The description of each half township is no followed by a description of each deposit developed in that half township. The 14 half township maps and 77 detail maps of the bauxite deposits in this series of reports give the locations and numbers of all the holes drilled on the project, except the deep holes drilled to test the geophysical anomalies. The locations at those holes show on figure 13 in volume I. The descriptions of the deposits developed are followed by complete detailed logs at the drill holes. Many at the widely spaced exploratory holes did not discover bauxite of minable thickness and gra.de. The pertinent information obtained from the widely spaced exploratory drill holes has been summarized and tabulated, and a table for each halt township is given with the discussion covering that area.

Jan 1, 1948

The 53 countries that constituted Africa in 1993 accounted for a significant portion of total world output of a number of mineral commodities. For the continent as a whole, world shares of most commodities showed little change from those of 1992 although most output volumes showed a slight decline. There were no significant production increases, but there were significant decreases of cobalt and copper because of political instability in Zaire and production problems in Zambia, of chromite resulting from cutbacks in South Africa and Zimbabwe, and of phosphate rock owing to a lower output by producers in general. (See tables 1 and 2.) Among the most significant mineral commodities produced in Africa, ranked by portion of world production in 1993, were diamond, cobalt, chromite, gold, phosphate rock, manganese ore, uranium and petroleum. Others of importance in world trade were andalusite, antimony, asbestos, bauxite, coal, copper, fluorspar, lithium minerals, platinum-group metals (PGM), titanium minerals (ilmenite and rutile), vanadium, vermiculite, and zircon. Several of these-chromite cobalt, diamond, and manganese-were not produced in the United States.

Jan 1, 1995

While coal occurs beneath about 18 percent of Utah, only 4 percent of the state has minable reserves. Utah's coal fields are mostly bituminous. Current coal production in Utah is largely by underground mining, making Utah unique among the coal-producing states. Most coal seams are more than 8 feet thick. Utah's coal resources are about 6.3 billion tons, 1.3 percent of the national reserve. Most of Utah's coal resources are held by the Federal Government and Indian tribes and are mined under lease. The climate of the Utah coal region is characterized by hot, dry summers and cold, relatively moist winters. Normal precipition varies from 6 inches in the lower valleys to more than 40 inches on some high plateaus. The growing season ranges from 5 months in some valleys to less than 3 months in mountainous regions. These extreme climatic conditions make reclamation difficult. Utah gained primacy when its regulatory program was conditionally approved January 21, 1981. Full program approval was obtained March 7, 1983. The Abandoned Mine Land Program was approved June 3,1983. A Federal Lands Cooperative Agreement was signed in March 1987; Utah performs all enforcement activities and some permitting activities on federal lands.

Jan 1, 1992

By M. C. Malamphy

A general description of the activities and results of bauxite investigation by the Bureau of Mines at its bauxite project in Saline and Pulaski Counties, Ark., has been given in Report of Investigations 4251. The factual data obtained during the project are reported in a series of Reports of Investigation beginning with No. 4251, of which this is the ninth. The data are accompanied by maps showing the location of holes drilled and the deposits developed. Each area upon which work was done is reported by half townships. Each bauxite deposit investigated was assigned a name and a number for ready reference and identification, and its location and name are shown on the appropriate half-township map. The description of each half township is followed by a description of each deposit developed in that half township map. The 14 half-township maps and 77 detail maps of the bauxite deposits in this series of reports give the locations and numbers of all the holes drilled on the project except the deep holes drilled to test the geophysical anomalies. The locations of those holes show on figure 13 in volume 1. The descriptions of the deposits developed are followed by complete detailed logs of the drill holes. Many of the widely spaced exploratory holes did not discover bauxite of minable thickness and grade. The pertinent information obtained from the widely spaced exploratory drill holes has been summarized and tabulated, and a table for each half township is given with the discussion covering that area.

Jan 1, 1948

By A. L. Toenges, F. A. Jones, J. N. Sxudder, E. R. Maize

"INTRODUCTION This report is the second of a series of studies of analysis of energy requirements and characteristics of various machines used in the production of coal in underground mines and the losses in distribution of energy to these machines. The test equipment used in these studies is described in Report of Investigations 3615. 7/ The preliminary study data and results of tests made on various types of mechanical-leading cutting, and transporting equipment at two mines. This report is analysis of the energy requirements of the energy requirements of the underground equipment of a third mine. An analysis of the use of energy and its distribution usually requires in a saving in energy consumption and the reduction of hazards. The distribution system should be designed to supply energy effectively and study for the efficient operation of all machines."

Feb 1, 1943

By H. S. Kalman

A table of factors for rapid, accurate calculation of the volume of pure helium in cylindrical steel containers, at base conditions of 14.7 psia and 70° F, is presented. The table covers a pressure range from 10 to 10,000 psin in 10-psi increments and a temperature range of 0° to 120° F in 2° increments. The volume of helium is calculated from the observed pressure and temperature of the helium, expressed as a factor from the table, and the known internal volume of the container. The calculation requires a single multiplication. A discussion and evaluation of the accuracy obtainable and a derivation of the formula used (which takes into account compressibility of helium, thermal expansion of steel containers, and the stretch of steel due to internal pressure) are presented. An example showing how the table can be used is given also.

Jan 1, 1968

By Chris Nelson

Two pieces of European Union (EU) legislation together establish requirements for protection against risks from vibration at work. The vibration directive1 specifies duties of employers to protect workers from risks from exposure to vibration; the machinery directive2, specifies duties of manufacturers and suppliers regarding the safety of machinery marketed in the EU. This paper discusses both directives and the standardisation programmes that support them. It also addresses the implementation of these requirements in Great Britain. Employers’ duties: the vibration directive This directive requires employers to assess and control risks to health and safety arising from hand-arm vibration (HAV) and whole-body vibration (WBV). Member States were required to implement the directive in national legislation by 6 July 2005. Employers are required to eliminate vibration risk at source, or reduced to a minimum. The duties include: assessing risk and exposure; planning and implementing the necessary risk control measures; providing and maintaining suitable work equipment; providing workers with information and training on risks and their control; and monitoring and reviewing the effectiveness of the risk control programme. Daily exposure exceeding a specified action value triggers a requirement for a programme of technical and organisational measures to minimise vibration exposures and the resulting risk, and the provision of health surveillance. Exposures above a specified limit value are prohibited. When conducting their risk assessments, employers are required to “assess and, if necessary, measure” the vibration exposure of workers, for comparison with the action and limit values. Vibration measurement in the workplace is not expected in all cases and the use of vibration information from equipment manufacturers is specifically mentioned. This provides a link with the machinery directive (see below). Manufacturers’ and suppliers’ duties: The machinery directive The machinery directive, first introduced in 1989, is intended to remove barriers to trade. It puts duties on manufacturers and suppliers who place machinery on the European market to design their products to eliminate or reduce risks to health and safety and to warn the user of any residual risks, providing information required for safe use (for example, operator training, maintenance and selection of consumables). There are specific requirements for minimising risk from vibration in the design and construction of the machine and, in the case of hand-held, hand-

Jan 6, 2006