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By F. L. Wideman

This report describes a computer program that is used for the calculation of the coordinates and elevations of subsidence survey pins located by intersection. This program was developed for the Federal Bureau of Mines by the Numerical Analysis Laboratory, University of Arizona. These calculations, although relatively simple, are both tedious and time-consuming when computed with a desk calculator and trigonometric tables. In this survey, a large number of pins were surveyed repeatedly, and it was evident that both time and money could be saved by using a digital computer.

Jan 1, 1962

By Greg Plutko

Laboratory testing has shown that the Marsh Funnel test can be significantly impacted by long-chain polymer entanglement. In general, shorter hydration time leads to more chain entanglement which in-turn, leads to higher marsh funnel values that values seen for longer mixing. This trend makes it very difficult to predict funnel-viscosity on successive days. Data is presented which helps to explain this chain interaction effect on Marsh Funnel data and how it differs from traditional Fann viscosity. The data suggest that this long-chain polymer entanglement occurs more in samples with less hydration time and decreases as hydration time increases. There is also suggestion that higher polymer concentrations have a greater drop-off in marsh funnel viscosity for a given aging length than do lower solids slurries. Fann rheology was shown to be much less impacted by the hydration time of the PHPA polymers than was Marsh Funnel viscosity. This suggests that the Marsh Funnel viscosity is impacted by some aspect of the slurry that does not affect Fann rheology as strongly. It is known from literature that longer-chained polymers have more potential to entangle and our data support the theory that the Marsh funnel viscosity is greatly impacted by this polymer-chain ‘roping’ entanglement.

By W. W. Adams

"The main purpose in the compilation of accident statistics is to reveal conditions that may result in injury to persons or property so that remedial measures may be applied. For practical reasons it is usually found necessary to restrict inquiry to conditions which actually have caused personal injury, and to omit those which nay, but have not yet, resulted in damage, Fortunately or unfortunately, there is a sufficient number of the former to indicate the existence of hazards so numerous as to require all of the attention which the industry can devote to the subject.Two years ago, the Bureau of 'mines, in cooperation with the National Safety Council, undertook an intensive campaign to obtain more complete and satisfactory information regarding mine accidents than had theretofore been available. Since 1911 the bureau had been receiving annual summaries from all companies operating metal mines, showing, in a general way, the number and causes of accidents that occurred during the preceding year and the number of men employed at the mines. Monthly summaries of fatal accidents at coal mines were received from the state inspectors, showing the number of deaths attributed to each of 22 main causes of accidents, Information for individual coal mines was not furnished.While this information, nation-wide in scope, is indispensable because it epitomizes the progress or retrogression in the industry as a whole, and serves as a background of specialized studies, yet certain classes of acci¬dents, for example, those that are more or less peculiar to specific districts or mines, require an analysis in greater detail than is possible on the sole basis afforded by the annual summaries.The need for more specific information was realized some years ago in the State of Pennsylvania in connection with the administration of the workmen's compensation law, The mining industry is well acquainted with the val¬uable studies of accidents, particularly nonfatal accidents, in the mines of that State being conducted by Mr. Rush N. Hosier."

Sep 1, 1924

By Donald E. Redmon

This Bureau of Mines report examines the injury experience in the quarrying industry for the years 1964-65. Twenty-eight tables for each year are presented in which disabling work injuries are summarized by department, source of injury, extent of disability, part of body injured, and nature of injury. Correlative information on employment, worktime, and operating activity is also presented.

Jan 1, 1973

By Gordon T. Austin

The combined value of production of natural abrasives, which include tripoli, special silica stone, garnet, staurolite, and emery, increased about 4% in 1990. The increase in the value of tripoli production was the result of an increase in the unit value. Emery increased owing to an in? crease in the volume of the material produced and an increase in the unit value. Special silica stone experienced a decrease in unit value and an increase in the quantity produced. Garnet showed a 10% in? crease in quantity and a 73% increase in unit value. Staurolite decreased about 8% in the quantity produced, and the value of production decreased about 10%. The fused aluminum oxide industry showed a 5% decline in the quantity produced and in the value of production. The silicon carbide industry saw a 10% decrease in the quantity produced and a 9% decrease in the value of production. Production for both industries decreased 7% in quantity and value compared with those of 1989.

Jan 1, 1993

By R. H. Nafziger

Owing to the growth of alloy steel production and its influence on tramp element levels when recycled, foundries have expressed concern regarding the quality of scrap used to prepare iron castings. Reliable and current information was unavailable on the amount of tramp elements contained in iron castings over time. Accordingly, the U.S. Bureau of Mines, in cooperation with the American Foundrymen's Society (AFS), analyzed cast iron samples from participating foundries throughout the United States on a quarterly basis to ascertain possible trends. Each sample was analyzed for 28 elements to determine if changes had occurred as a function of several input variables. This bulletin describes the research and presents analytical results and evaluations over a 5-3/4-year period from January 1981 to September 1986. Results show that iron casting compositions are changing with respect to a few tramp elements such as arsenic, cobalt, chromium, tin, and zinc over the period. Changes in charge compositions probably are responsible. Significant variations between zones also were observed with aluminum, arsenic, cobalt, chromium, copper, and manganese.

Jan 1, 1990

By Musa D. Manzi, Raymond J. Durrheim, Richard T. Masethe

An investigation into the source mechanism of mining-induced seismic activity plays a vital role in understanding the various modes of failure observed in the underground deep-level South African mining environment. The seismic events data for this study was captured by the mine-wide seismic system operating at Kloof Gold Mine. This system comprises 40 4.5 Hz tri-axial geophones sampling at 6 kHz installed at locations that surround the stopes mining the Ventersdorp Contact Reef (VCR), Main Reef (MR) and Kloof Reef (KR). A set of 103,753 mining-related seismic events (-3.0≤ ML ≤2.7) that occurred during 2017 and 2018 was selected for this study. The mining depth of these seismic events ranges from 1600 – 4200 m; most located close to stopes mining the VCR ore body. The main criteria used to select a subset of events for detailed analysis were the number of stations that recorded the seismic event and the azimuthal distribution of the sensors.

Apr 26, 2022

By Thomas E. Howard

Man has been engaged in the construction of tunnels in. rock for several thousand years. During that time, methods of tunneling have changed drastically. Hordes of men chipping away at the tunnel face have been replaced by mechanical drills and explosives and by tunnel boring machines. Spoil is no longer carried on the backs of humans, but is now removed by trains, trucks or conveyor systems. These and other changes have had the effect of greatly increasing the rate of tunneling, while at the same time, greatly decreasing the potential dangers to workmen. Although the techniques, equipment and material used for tunneling are being continually improved, rock tunneling is still a slow and expensive process. Significant improvements and innovations are needed to reduce the cost and time required for tunneling if we are to fully utilize the subsurface to aid in the solution of urban problems and in the conservation of resources. This report is intended to facilitate the orderly development of tunneling technology by focusing attention on the inadequacies of rock tunneling and the improvements that are needed. The data presented were derived from the results of a comprehensive questionnaire that was completed during the summer of 1969 by more than 600 individuals and organizations in 17 countries. Table 1 lists the countries and the number of replies from each. Appendix A contains a summary profile of the national responses, while the text presents the results and a brief analysis of the conclusions that might be derived from the data in the questionnaire. The data shown in Appendix A represent the consensus opinion of each of the 17 nations without regard to the number of individual replies or the amount of tunneling activity that is represented. The national consensus was determined for each country by a plurality of the individual responses, in some cases modified by the opinion of the rapporteur. Tire above procedures can lead to situations which are misleading. For example, experience and activity arc a rational basis for analysis; but, if national replies are weighted on this basis (i.e., number of responses), informed and valuable opinion of less active countries would probably be overwhelmed and lost. In analysing the data on the basis of national responses without weighting, it becomes apparent that many of the same problems exist under a given set of conditions regardless of the number of tunnels that have been driven.

Jan 1, 1970

This Bureau of Mines publication summarizes the industrial minerals industry of Idaho. It contains information on 119 principal deposits of 21 commodities in the State and describes the institutional and infrastructural factors affecting mineral development.

Jan 1, 1991

Several Approaches to Enhance the Bioleaching of Enargite Some approaches were investigated to enhance the recovery of Cu from enargite by bioleaching with Acidithiobacillus ferrooxidans using the galvanic interaction with pyrite and activated carbon, and with thermophilic bacteria, Acidianus brierleyi. Addition of pyrite initially enhanced Cu leaching by the Galvanic effect, but after that the formation of secondary minerals passivated the surface of enargite in inoculated batches. Activated carbon improved Cu recovery from enargite much better than pyrite, when it is contacted with enargite. Recovery of Cu from enargite has been recorded to at largest 2.4 per cent within 30 days in the presence of activated carbon when mesophilic bacteria were inoculated at 25¦C. The recovery of Cu from enargite was drastically enhanced by inoculation of thermophilic bacteria, Acidianus brierleyi, up to 60 per cent within 40 days at 70¦C and still not leveled off after 40 days unless the formation of Fe(III) precipitates occurred. After 40 days dissolved molar ratio of Cu/As is around 5.2, suggesting that metal-deficient sulfides and/or ferric arsenate might be formed on the surface of enargite.

Sep 13, 2010

By W. R. ARGYLE, R. A. SHERMAN, Henry Kreisinger, John Blizard, B. J. CROSS, A. R. Mumford

On entering the World War the United States was confronted with the necessity of building in a short time a large number of ships of tonnage adequate to transport troops and war materials to Europe and to carry food supplies to the allied countries, whose merchant fleets had suffered greatly by submarine warfare. The necessity of building ships quickly led to the formation of the United States Shipping Board, which was charged with the duty of developing an efficient organization for the purpose. Such an organization was developed under the name of the Emergency Fleet Corporation; it was under the control of the Government, but could conduct its business in the most direct way, like a private corporation. In order to build the largest- number of ships possible without drawing too heavily on the steel industry, which was already taxed heavily by the production of munitions, it was decided to build wooden as well as steel ships. These ships were built from a few standard designs to enable a large number of duplicate parts to be fabricated in inland shops and transported by railroad to the shipyards on the seacoast, where they were assembled into ships. In other words, the plan was to manufacture the ships rather than to build them. The shops on the seacoast were reserved to make those parts of the ships' equipment that could not readily be transported. The inland shops made the parts that could be transported to the seacoast by railroad. Among the more important parts of the ships' equipment to be standardized were the boilers. As the Scotch marine boiler in large units is bulky and can not be transported by railroad, and as, for the same capacity,much more steelis needed in its construction than for water-tube boilers, a few simple designs of water-tube boilers were developed that inland shops having ordinary equipment could make in large quantities.

Jan 1, 1924

By Richard P. Cislo

The evaluation of the effectiveness of the time domain Coal Interface Detector developed by the General Electric Company under contract H0155120 is the subject of this report. The sensor utilizes differences in the time characteristics of shearer vibrations as sensed by an accelerometer mounted on the ranging arm to discriminate the cutting of coal and rock. Pour identical time domain sensors were supplied by the Bureau for field evaluation. The performance of the time domain sensor was evaluated by an extensive field test and data collection program that included four longwall mines and a total of nine mine visits. The intent was to determine the sensor's applicability to a wide range of mining conditions and to document its limitations. Results of the extensive field tests indicate that shearer vibration data processed by GE's time domain signal processing algorithm cannot be used to reliably detect when the cutting drum crossed the coal/rock interface.

Jan 1, 1987

By Warren E. Morrison

A simplified energy model for the United States is quantified for a recent historical period. The basic model and calculated quantified structures are used for a number of analytical case studies that estimate midterm and long-range shifts in patterns of energy resources demand and required supply. Historical data series are presented for the years 1947 to 1965 in the form of integrated energy balances by source, form, and consuming sector. In case studies I to XII, conditional projections of historical trends of energy demand and required supply are made for the midterm period 1966 to 1980. The projections are carried out by correlation of major energy components with relevant independent variables such as major economic indicators. Simulations of the medium-range projections to 1980 are carried out by varying the assumptions for the determining variables to produce high-and low-range projections for the midterm period. Case studies XIII to XXII are long term contingency or technological forecasts to the year 2000. These cases assume technological changes or innovations that produce major shifts in the long term pattern of energy consumption and the mix of required resources. The domestic resource base is assessed in its ability to meet projected or forecast demand for energy resources under the midterm and longrun assumptions made in the various case studies. Various energy issues or problems identified from the analyses of the case studies are discussed, and possible alternative approaches to solutions to these issues or problems are suggested.

Jan 1, 1968

By K. L. Paciorek

The aim of the present study was to determine the thermal oxidative behavior of materials used in coal mines, with emphasis on the type and relative concentration of the products, in particular the toxic species formed. To supplement this work and to gain understanding as to the type of products possibly formed and also to assess the limitations and advantages of the various analytical methods used a literature survey of the past investigations performed on the compositions of direct interest to the subject program was conducted. The compositions thus covered were cellulose, polyvinyl chloride, neoprene, urethanes, polyamides, polyesters, polyethylene, epoxy, phenoxy, urea-formaldehyde and melamine formaldehyde resins. The results of this review are compiled in the Appendix. The experimental work consisted of thermal oxidative degradation of 36 materials and 4 composites using a stagnation burner apparatus developed in these laboratories which affords a dynamic system approximating somewhat the conditions encountered in underground coal mines. This technique as employed during this program gave only the relative product concentration at specific periods of the decomposition process, The advantage of this approach is that in this manner screening of materials can be accomplished in conjunction with some assessment of the decomposition rate as influenced by temperature and material composition. Limited static tests were performed using a sealed tube method. The materials studied were grouped according to their compositions. The following were the main groups: (a) polyvinyl chloride-containing materials, (b) neoprene compositions, (c) rigid foams (urethanes, isocyanates), (d) miscellaneous materials (including jute, fiberglass, polyethylene and some articles of unknown composition), (e) coal and fluids (phosphate esters, organic esters, oil-water emulsions), and finally (J) composites. The latter comprised a mixture of a phosphate ester fluid with (a) coal, (b) a representative polyvinyl chloride sample, and (c) a neoprene type composition.

Jan 1, 1972

Explosives are used to mine coal. Any blast results in three size categories of products, namely over-, middle-, and under-size. Boulders can still be broken smaller in further operations after blasting. The under-size, for instance coal fines, negatively affects the mining efficiency. Their reduction ensures better returns. The paper concerns investigations aimed at reducing coal fines' generation. Inherent fractures are identified as one of source of fines. The discussion is therefore centered on establishing a relationship between the fracture occurrence, the explosive properties and the blast outputs evaluated in terms of the fines generated.

Jan 1, 1996

By W. W. Adams

The metal and nonmetallic mineral mines (excluding coal mines) of the United States had a more favorable safety record in 1935 than in any year except 1931 and 1932 since annual statistics of accidents first became available in 1911. The accident rate was even lower than that for 1911, when the recorded rate probably did not reflect all of the accidents that actually occurred because many companies had not yet begun to keep complete records of accidents, especially those causing only minor injuries, and when, therefore, the number of accidents revealed by the companies' reports to the Bureau of Mines was probably not as complete as that reported for later years. Compared. with 1911, the accident rate covering fatal and nonfatal injuries in. 1935 decreased 13 percent. Compared with 1925, when the rate was the highest ever reported, the rate for 1935 decreased 47 percent and compared with 1934, 7 percent. The progress in safety which the mines of the country made in 1935 was not confined to any section or mining region; it was shared by a majority of the mining States and applied to underground mining operations, to open-pit mining, and to work at surface shops and yards. The rate for underground mining declined 8 percent from 1934; the rate for open-pit mining declined 14 percent, and that for surface shops and yards 12 percent.

Jan 1, 1938

By L. P. Larson

In this Bureau of Mines evaluation of the domestic supply position of tungsten, certain tungsten resources in the United States are estimated as to quantity and grade and then are systematically costed in detail (excluding exploration costs). A supply curve is developed which depicts the quantity of tungsten (WO3) up to about 15.5 million short ton units that is producible at calculated price levels ranging from about $13 to $125 per short ton unit. About 10.4 million short ton units are available at a calculated price that is less than the present market price ($40). Total known resources amount to about 40.2 million short ton units. A very large portion of that quantity was not costed due to inadequate information on either resources or processing methods. Further exploration and research would have a significant effect on the availability of tungsten in the United States.

Jan 1, 1971

By Michael E. Henderson

The U.S. Bureau of Mines (BOM) constructed the Hydraulic Transport Research Facility (HTRF) to investigate the hydraulic parameters relating to the transport of coarse coal. To achieve these goals in a timely and efficient manner, the Bureau contracted to Boeing Services International (BSI) the responsibility of operating the HTRF and providing technical support. This data report is a summary of the testing and data results for the period 22 November to 10 December 1982. The testing covered herein is for coarse 2-in by 0 (minus 50 mm) Pittsburgh Seam coal in a 6-in (150 mm) pipeline, at velocities ranging from 5 to 20 ft/s (1.5 to 6.1 m/s) and at concentrations ranging from 15 to 45 pct by weight.

Jan 1, 1986

By D. C. Dahlin

To identify and characterize potential domestic chromium resources, the Bureau of Mines investigated podifom chromite deposits along the Border Ranges Fault in southern Alaska. Part 1 of this two-part report describes an extensive field investigation and preliminary resource evaluation studies by the Bureau's Alaska Field Operations Center. This paper, part 2, describes the mineralogy of 38 samples that were collected from low-grade deposits in the Chugach Mountains, on the Kenai Peninsula, and on Kodiak Island, and presents the results of laboratory batch beneficiation tests designed to concentrate the chromite. The samples are peridotites and chromites that consist primarily of variable amounts of chromite, olivine, and serpentine. They were beneficiated by a sequence of grinding, sizing, and gravity concentration operations. Twenty-four high-chromium or marginal high-chromium chromite concentrates, six high-iron or marginal high-iron chromite concentrates, and five submarginal concentrates were produced with chromium recoveries that ranged from 37 to 95 pct. Three very low-grade samples were not beneficiated. These results indicate that several of the de- posits may be significant chromium resources, Potential precious metals association with the chromite was also investigated. Analysis of these samples indicates that the chromite deposits are not good platinum sources.

Jan 1, 1985

By Francis Church Lincoln, Paul Zinner

"Attention of the Bureau of Mines was first directed to the Gray farm area by the results of several exploratory churn-drill holes completed by the New Jersey Zinc Co., and later by Roland J. Teske and by Judge H. L. Heer.When the Bureau of Mines initiated its investigation of the area, all drilling on the Gray farm had been discontinued, and no mining had resulted from the exploratory work. However, in the opinion of the Illinois Geological Survey, the Federal Geological Survey, and the Federal Bureau of Mines, this drilling,with the preliminary geological studies, was considered sufficient evidence to justify continued exploration to the southeast along a projection of the trend of mineralization developed in the mines to the northwest, or the so-called Black Jack Trough.This report describes the work done and presents the data obtained during the period of Bureau of Mines exploratory work.In its program of exploration of mineral deposits, the Bureau of Mines has as its Primary objective the more effective utilization of our mineral resources to the end that they make the greatest possible contribution to national security and economy. It is the policy of the Bureau to publish the facts developed by each exploratory project as soon as practicable after its conclusion. The Mining Branch, Lowell B. Moon, chief, conducts preliminary examinations, performs the actual exploratory work, and prepares the final report. The Metallurgical Branch, R. G. Knickerbocker, chief, analyzes samples and performs beneficiation tests. Both these branches are under the supervision or Dr. R. S. Dean, assistant director.Special acknowledgment is due Paul Herbert, geologist, Illinois Geological Survey, for his studies of cores, which greatly influenced the planning and progress of the exploratory work. Acknowledgment is also made to A. F. Agnew and A. V. Heyl, geologists, Federal Geological Survey, for their invaluable aid; to 0. W. Terry, F. C. Lincoln, M. H. Berliner, A. M. Cummings, project engineers; and to E. P. Barrett, district engineer, Minneapolis, and E. D. Gardner, regional engineer, Rolla, Mo., for supervising the program.The Gray ore body is on the Gray farm 5 miles south of Galena in Jo Daviess County, northwestern Illinois. The location with respect to adjoining properties is shown on figure 1. Galena is a city of 4,000 population on the banks of the Galena River, a stream that was formerly navigable by Mississippi River steamers but has now shrunk to the dimensions of a small creek. A gravel road leads from the city to the Gray farm and onward to the Bautsch and Boevers farms to the south of it."

Sep 1, 1946