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By Kevin Connor

During 1986, the Government continued with efforts to ease the country's almost total reliance on coffee exports for trade revenues by allocating 45% of the Government's budget to commerce and industrial projects. The collapse in coffee prices in 1985 continued to exacerbate the country's growing trade deficit, weakened currency, and dwindling reserves of foreign exchange in 1986. Amoco Burundi Petroleum Corp., a subsidiary of Amoco International Oil Co., continued with plans to drill at least two exploration wells in Lake Tanganyika in 1987. Both offshore and onshore drilling exploration was planned by Amoco Burundi. Any oil or gas finds were expected to have substantial impact on the Burundian economy, as a major portion of the country's trade deficit was directly attributable to petroleum and gas imports.

Jan 1, 1988

By V. A. Danielson

The Bureau of Mines examined sources, consumption, and movement of iron and steel scrap in the southeastern States--Alabama, Florida, Georgia, Kentucky, North Carolina, South Carolina, and Tennessee. Officials of the scrap-processing and scrap-consuming industries were interviewed, data was obtained from the published literature, and a canvass was made by the Bureau of scrap consumers. The Southeast generated excess scrap which was shipped to domestic and foreign consumers in about equal proportion. Total 1963 demand in the Southeast was 3,336,000 net tons, of which purchased scrap was 75 percent, foreign exports 13 percent, and domestic exports 12 percent. Alabama, with 47 percent of the purchased scrap consumption in 1963, was the most important scrap-consuming State, and Kentucky, with 34 percent, was the second most important one. Southeast demand was 4.8 per-cent of the total U.S. demand. Projected 1980 consumption is 8,340,000 tons. Scrap prices showed a slight downward trend for the period 1953-63, although gross consumption increased slightly. A significant trend in processing scrap in the Southeast is the preparation of smaller bundles or "briquettes" weighing from 75 to 150 pounds, which are easier for consumers to handle and inspect. Another significant development is the "shredding" of automobile scrap which produces a dense, clean scrap especially desirable for use in electric furnaces.

Jan 1, 1967

By Constantine C. Popoff

The Hermada antimony deposit is in the Sewtooth Range in southwestern Idaho, about 77 miles by road northeast of Boise. Stibnite mineralization occurs over an area one mile wide from west to east and two miles long. It is locally referred to as the Swanholm district. In 1947 high- grade stibnite ore was discovered on the East Fork of Swanholm Creek. Since then, ore in commercial quantity has been produced by the Hermada Mining Co. The total output for 1947-50 was about 5,000 tons of ore, containing 640 short tons of antimony metal.

Jan 1, 1953

By Karl R. Becker

A variety of commercial detonators (fuse type and electric instantaneous and delay types) were subjected to impact and thermal stimuli to determine initiation stimulus levels and the dominant parameters in resistance to initiation. In the impact trials the detonators were impacted along their length to find the most sensitive region; threshold initiation limits obtained for these regions ranged from 3.47 to 20.82 joules (2.6 to 15.4 ft-lb). The friction sensitivity of the explosive component was an important parameter in determining sensitivity; various construction features of nonexplosive components played a role as well. In the thermal sensitivity trials, the detonators were heated from ambient to 100° C at an average rate of about 1.0° C/min, and thereafter at 0.5° C/min until they exploded; the explosion temperatures observed ranged from 121° to 188° C. These temperatures correlated quite well with the reaction temperatures of certain characteristic explosive components used by different manufacturers. The data also indicated an effect of confinement on explosion temperatures of detonators.

Jan 1, 1975

By W. J. McConnell, C. P. Yaglaglou

"IntroductionThis paper on the kata thermometer is issued by the Bureau of Mines on account of the general interest in this instrument and the fact that it is frequently used in studies of mine ventilation conditions with regard to comfort and health of miners. It has been used in the studies being conducted along this line by the Bureau of Mines on the effects of high temperatures and humidities of air in mine working on the comfort conditions, as well as in studies of atmospheric conditions in mine, railway and vehicular tunnels.The study of the various physiological responses of the human body to different degrees of temperature combined with different percentages of relative humility in still and in moving air, now being conducted at the Pittsburgh experiment station of the bureau in the research laboratory of the American Society of Heating and Ventilating Engineers, cooperating with the Bureau of and the U. S. Public Health Service, presents an added opportunity of investigating the instruments that have been devised to measure atmospheric conditions as they affect the comfort and health of human beings.The ordinary mercury thermometer, as pointed out by Heberden3 almost hundred years ago is a very inadequate instrument for measuring the physiological effects of atmospheric conditions. It merely accounts for that part of the body heat lost by raliation and convection, while as a matter of fact greater part of the body heat resulting from the metabolic process within the body is eliminated by means of evaporation from the surface of the body."

Jan 1, 1924

By Ginger S. Evans

This report documents a preliminary hydrologic investigation of an area where longwall mining methods are to be used. The scope of work includes: determination of physical and chemical characteristics of major soil types in the area; determination of physical and chemical properties of surface water bodies; collection of geologic characteristics, including stratigraphy, structure, and detailed aquifer descriptions; collection of 10 years' meteorological data and installation of a weather station; and a detailed ground-water investigation that includes completion of observation wells, aquifer testing, water quality sampling, and analysis using a 3-D computer model. The Trescott model developed by USGS was used to simulate steady-state aquifer conditions. Input data from 8 multiple-completion monitor wells were used to model an area of approximately 10 square miles. Two layers, coal and overburden, were simulated, both confined. Model results showed good agreement with know piezometric data, desaturated areas, and flow from springs. The study area was found to have very low-yield bedrock aquifers with transmissivities ranging from 5 to 320 ft2/day for the coal (depths from 500 to 1,200 ft) and from 499 to 576 ft2/day and fractured sandstone units (depths less than 100 ft). Annual precipitation and recharge are very low, 10 to 11 inches and 0.25 inch respectively. The area has very high relief and large areas of rock outcrop. No perennial streams are present on the site.

Jan 1, 1983

On April 1, 1982, the Bureau of Mines and the Department of Energy entered into an Interagency Agreement to develop an enhanced computer cost model for uranium in situ leach mining. The original computer cost model contained data base information related to two regions; the Wyoming basin region and the South Texas trend area. The enhanced cost model contains additional information on San Juan Basin type deposits. This addition is significant because it expands the model's capabilites to include one of the largest uranium producing areas in the United States and developes costs related to uranium production from in situ leach mining. The data base was expanded and modified to include changes necessary for San Juan basin type deposits. These changes included, but were not limited to, state and local taxes, royalty payments, depth of deposits, drilling costs, and electrical costs. Also site visits were taken to verify many of the base case parameters. Consequently, the data base has been incorporated into the computer program and existing software was modified to provide for the additional data. Information was obtained on drilling coats and therefore the current program more accurately reflects these costs to depths of 2500 feet. This depth parameter has been expanded to include Wyoming Basin and South Texas scenarios also. Verbal communications were held with one operator in the Crownpoint, New Mexico area as well as the state regulatory agencies to help validate the expanded model. As a result of these changes, several tables have been included, summarizing changes in the new default parameters and the overall range of input parameters.

Jan 1, 1982

By W. M. Dressel

This Bureau of Mines report describes a shaft closure demonstration project in which 11 inverted pyramid-shaped plugs were used to plug abandoned open mine shafts in Galena, KS, The inverted pyramid-shaped forms, fabricated from steelplate, were designed so that the inverted base would be larger, by 4 ft on a side, than the approximate size of the shaft opening at the surface residuum-solid rock interface. After the surface openings of the shafts were trimmed with a backhoe, the steel forms, complete with reinforcing, were lowered into the openings and filled with concrete; the remaining portions of the openings above the plugs were backfilled to slightly above the surrounding surface level with waste rock and soil. Location and elevation monuments were installed for long-tern evaluation of the success of the project.

Jan 1, 1985

By John C. Hartley

Three systems that monitor ventilating fans are described. These electronic monitoring systems automatically perform most of the operations required to conform with the provisions of the Federal Mine Safety Code in the event of fan failure or slowdown.

Jan 1, 1964

This report summarizes the work performed and results achieved in the period from 18 June 1971 through 18 October 1971 under Phase I (Task 1: Literature and Industry Search; Task 2: Conceptual Design and Evaluation; and Task 3: Concept Selection and Preliminary Design) in substantiation of the drill/impregnation machine concept recommended for detailed design in Phase II. Also included as Task 5 are recommendations for an experimental investigation to be conducted during Phase II. The report is submitted for approval and authorization to proceed to Phase II.

Jan 1, 1972

By Donna L. Anderson

This U.S. Bureau of Mines report describes a system to determine the position and heading of a continuous mining machine during the maneuvers required at the face area of a mine. The system consists of commercially available angular position sensors and a computer interface developed and tested at the Bureau. The sensors employed are laser-based scanning devices that report the angular location of retroreflective targets within their 90° field-of-view. The targets are mounted on the continuous mining machine; the laser scanners are mounted on an external reference structure. The computer interface consists of a single-board computer-controller programmed to gather and process the angular position information, and to calculate the machine's position and heading relative to the reference structure. A sensor fusion algorithm will be incorporated into the computer interface programming to increase the accuracy and reliability of the system.

Jan 1, 1989

By Michael G. Zabetakis

Limits of flammability of normal propyl nitrate (NPN) vapor were investigated at ambient and elevated temperatures. Minimum spontaneous ignition and decomposition temperatures were determined with laboratory apparatus over the pressure range from 0 to 4,000 p.s.i.g. Flame speeds and the detonation susceptibility of NPN vapor were measured at elevated temperatures. Stable detonation was obtained with liquid NPN at elevated temperatures, and the detonation velocity was determined to be between 4,700 and 5,100 m./sec.

Jan 1, 1962

By Kenneth H. Johnston

This publication describes a thermal-recovery project and two waterflood projects in Carter, Garvin, and Stephens Counties, Okla., that will be visited during the 1966 annual tour by the Bureau of Mines in cooperation with the Kansas-Oklahoma Waterflood Association. Among the unique features of the projects arc (1) the movement of heavy (15° to 28° API gravity) crude oil through the reservoir and into the well bore with energy furnished by burning a portion of the crude oil therein; (2) the use of an inverted nine-spot pattern with dually completed injection wells, to produce oil from deep (8,200 to 10,200 feet) reservoirs; and (3) the flooding of five sand lenses separately by using controlled water injections through multizone completed injection wells. Discussion of the individual projects includes information on their early history, method of completing and operating wells, source and treatment of injection fluids, oil production decline curves, and the results obtained from the development.

Jan 1, 1966

By Kenneth H. Johnston

This publication describes a thermal-recovery project and two waterflood projects in Carter, Garvin, and Stephens Counties, Okla., that will be visited during the 1966 annual tour by the Bureau of Mines in cooperation with the Kansas-Oklahoma Waterflood Association. Among the unique features of the projects arc (1) the movement of heavy (15° to 28° API gravity) crude oil through the reservoir and into the well bore with energy furnished by burning a portion of the crude oil therein; (2) the use of an inverted nine-spot pattern with dually completed injection wells, to produce oil from deep (8,200 to 10,200 feet) reservoirs; and (3) the flooding of five sand lenses separately by using controlled water injections through multizone completed injection wells. Discussion of the individual projects includes information on their early history, method of completing and operating wells, source and treatment of injection fluids, oil production decline curves, and the results obtained from the development.

Jan 1, 1966

By W. I. Garms

This paper, describing the milling practices at the Hayden concentrator of the Nevada Consolidated Copper Co. is the first of a Series being prepared by the Bureau of Mines on milling methods and costs in various districts of the United States. The Hayden concentrator is located at Hayden, Gila County, Ariz., 20 miles from the mine at Ray, Pinal County, Ariz., and approximately 1-1/2 miles north of the junction of the Gila and San Pedro Rivers. During the fourth quarter of 1928 the concentrator treated daily by flotation an average of 10,336 tons of ore containing 1.25 per cent of copper. The average recovery during this period amounted to 87.84 per cent of the total copper. The concentrates contained 19.88 per cent of copper.

Jan 1, 1930

This is the first publication in a projected series of reports on properties of commercial motor fuels pursuant to a cooperative agreement between the Cooperative Fuel Research (C.F.R.) Committee and the Bureau of Mines of the Department of the Interior. The report gives results of analyses in oil-company laboratories of sample of gasoline obtained from service-station pumps in 18 marketing areas by representatives of oil companies. These companies obtained the samples and analyzed them for their own information and supplied data from their laboratory reports to the Bureau of Mines for compilation and publication. History of Bureau of Mines Gasoline Surveys The following quotation from Report of Investigations 31624/ is included in this place for the information of readers who are not familiar with the Bureau of Mines gasoline surveys that have preceded the present report:

Jan 1, 1936

By E. C. Lane

This is the first publication in a projected series of reports on properties of commercial motor fuels pursuant to a cooperative agreement between the Cooperative Fuel Research (C.F.R.) Committee and the Bureau of Mines of the Department of the Interior. The report gives results of analyses in oil-company laboratories of samples of gasoline obtained from service-station pumps in 18 marketing areas by representatives of oil companies. These companies obtained the samples and analyzed them for their own information and supplied data from their laboratory reports to the Bureau of Mines for compilation and publication. History of Bureau of Mines Gasoline Surveys The following quotation from Report of Investigations 3162/4 is included in this place for the information of readers who are not familiar with the Bureau of Mines gasoline surveys that have preceded the present report:

Jan 1, 1936

By Dale R. Ralston

This investigation was divided into two major phases. Phase I of the study was an examination of the occurrence and production of acid water within the Bunker Hill Mine in northern Idaho. The second phase of the project involved the study of water movement through an abandoned tailings pile. Mineralogy and hydrogeology were determined to be the two most important factors in the acid mine drainage problem. Low pH water was formed in the mine in areas of lead-zinc ore rich in pyrite. Water movement in the mine was important in the production of acid and the transportation of heavy metals. Areas of recharge to the mine were identified. A data collection network was installed to monitor water quality and quantity changes. The quantity of acid drainage from the mine was found to vary directly with surface runoff events. The study of the abandoned tailings pile was performed to determine the characteristics of water movement through the tailings material and the resultant impact on the hydrologic environment. The Page Tailings Pile, abandoned in 1969, was utilized as a study area. An extensive network of piezometers and meteorological data collection sites were installed in and near the pile. Data collected to date indicate the presence of a ground-water mound under the east half of the pile. Some transfer of ions from the tailings pile to the ground-water system has been detected.

Jan 1, 1973

By Arthur V. Petty

The Bureau of Mines has researched the utilization of mining and pro-cessing wastes as raw materials for the production of glass-ceramic pipe. Characterization of various wastes as to occurrence and chemical composition is reported. A computer program was developed and used to identify waste materials and mixes that would result in glass melts from which glass-ceramics could be produced after cooling and subsequent heat treatments. The production of abrasion-resistant pipe from inexpensive and readily available domestic resources could offer an economical substitute for high-alloy steels containing the critical and strategic materials cobalt and chromium.

Jan 1, 1984

By J. Sammarco

Proper illumination is critical to a miner?s ability to detect hazards in underground mines. Moving hazards are often located in the miner?s peripheral field-of-view, while slip/trip/ fall hazards are often located in the forward field-of-view. The objective of the research described in this paper was to determine if light-emitting diodes (LEDs) improve visual performance as compared to traditional incandescent (INC) cap lamps. The research presented focuses on comparative studies of a National Institute for Occupational Safety and Health (NIOSH) prototype LED, a commercial LED and an INC camp lamp. Thirty subjects participated in these studies, with ten subjects in each of the following age groups: 18 to 25 years, 40 to 50 years and 51+ years old. Visual per­formance was quantified by the subjects? speed and accuracy in detecting hazards, while visual performance for disability glare was quantified by the use of contrast sensitivity tests. Results suggest that LEDs with a visible spectrum containing a higher concentration of the shorter wavelengths can enable visual performance improvements with respect to disability glare, the detection of moving hazards in the peripheral field-of-view and the detection of floor hazards in the forward field-of-view. The NIOSH prototype LED cap lamp provided the best visual performance improvements for the older age groups in every test.

Jan 1, 2009