Search Documents

By L. B. Pankratzt

The heat content above 298.15° K of ferroelectric lithium columbate (LiCbO3) was measured to 1,770° K. The Curie temperature was determined to be 1,450° K, the melting point 1,540° K, and the heat of fusion 16.94 kcal/mole. Heat content and entropy increments have been tabulated for the temperature range from i98.15° to 1,800° K. Heat contents are also given in equation form.

Jan 1, 1966

By William R. Wayment, David E. Nicholson

A modified percolation - rate test is proposed for use in determining flow rates through hydraulic backfill ; in contrast to the conventional test , a percolation- rate versus void - ratio relationship is established . requirements and a detailed test procedure are described . Equipment Results of a conventional test are compared with those of the proposed modified test . The proposed modified test method yields more accurate , realistic , and usable percolation- rate ( permeability ) data . The significance of obtaining accurate percolation rates for use in analyzing waterflow through hydraulic backfill is discussed .

Jan 1, 1964

By Richard A. Winters

The 31,880-acre Battle Creek Wilderness Study Area (WSA) was evaluated for mineral resources by the U.S. Bureau of Mines in 1984. No mining district is in the area, nor were any mines or claims recorded or found. Oil and gas leases, or lease applications, covered about half the area in early 1984. No known exploration has occurred. The entire WSA is covered with thick volcanic flows. Faults in these volcanic rocks may have provided conduits for mineralizing solutions emanating from the basement rocks; however, no evidence of mineral deposits was detected from rock samples collected along the faults. Reconnaissance samples from sand and gravel deposits yielded gold at less than $0.02/yd3. The source of the gold is assumed to be intrusive rocks or the Challis Volcanics about 20 miles north of the study area near the headwaters of Battle Creek. No economic concentrations of minerals were found in the WSA. INTRODUCTION Mineral surveys of designated wilderness study areas (WSAs) 1/ are conducted by the U.S. Bureau of Mines (USBM) and the U.S. Geological Survey (USGS) at the request of the U.S. Bureau of Land Management (BLM). The USBM researches the mining and mineral exploration history and evaluates mines, prospects, and mineralized areas within or adjacent to WSAs. The USGS studies WSAs by regional geochemical and geophysical surveys and geological mapping. The USBM and the USGS investigations are summarized in a joint report used to help determine the suitability of WSAs for inclusion into the National Wilderness Preservation System. Although the immediate goal of this USBM study is to provide data for the President, Congress, BLM, and the general public for land-use decisions, the long-term objective is to help insure that the Nation has an adequate and dependable supply of minerals at reasonable cost.

Jan 1, 1985

By Hillary W. Clair

An equation is derived for the rate of reaction of a sphere of metal oxide in a restricted enclosure through which a reducing gas is flowing . The equation takes into consideration the reaction rate coefficient , transport through the gas and through the porous shell of reduced oxide , the rate of gas flow , and the volume of the enclosure . The equation serves as a model for predicting the course of reduction of a particle of metal oxide in a shaft furnace .

Jan 1, 1964

By H. G. Iverson

The purpose of this investigation was to beneficiate the Talladega gray iron ores by flotation. A component of the problem was the determination of the degree of beneficiation possible by flotation as well as the relative selectivity of certain reagents in promoting flotation of either the iron minerals or the siliceous gangue minerals. The scope of the present investigation involved only the use of small-scale laboratory equipment. Treatment by roasting and magnetic separation was not included in this study, inasmuch as a similar comprehensive investigation was completed and the results were published by the Bureau of Mines in 1927. The results of the work on Talladega iron ores are briefly summarized in this report. In the search for efficient and economic methods of beneficiating low-grade iron ores, the flotation process is among those that are receiving considerable attention. The Talladega ores are of particular interest for a flotation study, because they contain two iron minerals (magnetite and specular hematite) that are somewhat dissimilar in their flotative response.

Jan 1, 1949

By K. J. Liles

This Bureau of Mines paper describes the composition and properties of drilling fluids for use in high-temperature geothermal wells, and summarizes the problems encountered with fluid use at the known major geothermal sites throughout the world. These include the western continental United States, Hawaii, Italy, Iceland, Japan, New Zealand, and Turkey. Water-base drilling fluids of 9- to 10-lb/gal weights are relied on primarily for geothermal well use, although air drilling is sometimes used. Bentonite-lignite-water systems have been used most often, and additives such as polyacrylates, lignosulfonates, and chromates are employed to improve the properties of the basic system.

Jan 1, 1976

By E. C. Lane

The motor gasoline that is being marketed in the United States this summer is slightly more volatile than that sold a year ago. The increase in volatility is shown by a lowering of the distillation temperatures, ranging from 2°F. at the average initial boiling point to 4°F. at the average end point. During the past nine years the Bureau of Mines has made semiannual surveys of the gasoline marketed in the United States, the survey just completed being the eighteenth in the series. The cities in which samples were collected have been chosen as representative of the more important marketing territories, as it is obviously impracticable to obtain a sample of every gasoline sold in the entire country. Samples were collected in Omaha as well as in the 11 cities where samples were taken last winter. It was believed advisable to include samples from Omaha in order to give a better balance to the survey for the country as a whole.

Jan 1, 1928

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 James W. Townsend

[The Harrington-Hickory mine in the Star raining district, Beaver County, Utah, has produced approximately 20,000 tons of lead-zinc-silver ores since 1910. Production previous to 1910 is not known. The mine is owned by the New Majestic Mining Co. The property was rehabilitated and operated by James D. Williams under a 10-year lease with option to purchase from April 1943 to May 1949, Loans from the Reconstruction Finance Corporation in the aggregate of $41,000 wore used in construction of an access road, rehabilitation of the mine, and purchase of equipment for full-scale operation. The improved, all-weather access road extends from loading ramps on the Union Pacific Railroad at Milord to the urine storage bins 5 miles west o f town. The mine is serviced electrically by a. 5,000-volt line owned by Telluride Power Co. Mine transformers step the voltage down to 440/220/110 for surface and underground service.]

Jan 1, 1953

By Sidney Katell

An economic analysis of underground gasification of coal, based on experimental results obtained by the Bureau of Mines, indicates that a gas suitable for use in a power plant might be produced for approximately $.62 to $.77 per million British thermal units. This estimate does not include cost of land purchase. The gasification experiments were conducted in a 3-ft. seam of high volatile A bituminous coal. The major factors which can influence a change in operating costs are height of overburden, power costs, thermal efficiency, and the gasification air inlet pressure. The following equations show the relationship of these factors to operating costs:

Jan 1, 1961

By V. F. Parry, J. B. Goodman, W. S. Landers

"This investigation was conducted: under the direction of A.C. Fieldner, chief, Fuel and Explosives Branch, Bureau of Mines, Washington, D. C. The following members of a Technical .advisory Committee were helpful in advancing the investigation: L. C. Harrington, dean, College of Engineering, University of North Dakota; D. F. Pane, president, Sheridan-Wyoming Coal Co.; Carson W. Smith, president, Consolidated goal & Coke Co.; Durbin van Law, consulting, engineer, Denver & Rio Grande Western Railroad; and C. B. Carpenter, professor of metallurgy, Colorado School of Mines. Coal samples from the Northern Colorado field used in the stoker during 3 years of service were supplied through the cooperation of N. C. Brooks, secretary, Northern Colorado Coals, Inc.This report describes the development and practical tests made on a small stoker-fired system for heating service water automatically. The system was designed to take advantage of the favorable reactivity of low-rank fuels, and the objective was to devise a combination of stoker, heat-receiving, and hot-water storage system Which would be automatic for at least 30 days without attention, while heating service water at minimum cost. The system was developed to a point where coal consumption was less than 10 pounds (or less than 100,000 B.t.u.) per day. The total operating cost of hot water for an average-family-was about $1.00 per month, with coal retailing at $6.00 per ton and electric power at 4 cents a kilowatt-hour. The heating system was designed for the utilization of low-rank fuels, but the general features of the double-tank system can be 'employed fuels, either gas or liquid fuels.The Subbituminous Coal and Lignite Section of the Bureau of Mines began investigations on the utilization of low-rank fuels in domestic appliances during 1939. Tests were made on various devices to find out if they were suitable for the low-rank fuels. Most of the available appliances for burning coal have been designed for the higher-rank fuels, and they are not well-suited for burning the lower-rank coals at maximum efficiency, because subbituminous coals and lignite have high bed moisture ranging between 20 and 40 percent by weight, which lowers heating value to the range of 10,000 to 6,500 B.t.u. per pound. They are noncoking, and the ash content ranges between 4 and 6 percent, with a fusion temperature of about 2,0000 F."

Jun 1, 1946

By M. W. Von Bernewitz, E. H. Denny

The use of oxygen breathing apparatus during rescue and recovery operations at both coal and metal mines has become so commonplace that there is a tendency for the industry not to give such apparetus the full measure of credit that it deserves in any particular disaster , therefore , the data presented herein should give some idea of what has been done in this regard during the past 15 years that is , up to 1910 by the Technologic Branch of the U. S. Geological Survey , and thence ( to the end of 1922) by the U. S. Bureau of Mines .

Feb 1, 1923

By Rolf S. Paine

The Bureau of Mines studied the presplitting technique used for control-ling overbreakage in the walls of a vertical shaft at the U.S. Army Corps of Engineers Littleville Dam project near Huntington, Mass. The periphery of the shaft, the dimensions of which were 16-1/2 feet wide by 21 feet long and 52 feet deep, was presplit (cracked) in the solid to a depth of 48 feet prior to full-depth sinking. Presplitting prevented overbreak in a fairly soft schist and provided sound self-supporting walls which required very little scaling.

Jan 1, 1965

By Rolf S. Paine

The Bureau of Mines studied the presplitting technique used for control-ling overbreakage in the walls of a vertical shaft at the U.S. Army Corps of Engineers Littleville Dam project near Huntington, Mass. The periphery of the shaft, the dimensions of which were 16-1/2 feet wide by 21 feet long and 52 feet deep, was presplit (cracked) in the solid to a depth of 48 feet prior to full-depth sinking. Presplitting prevented overbreak in a fairly soft schist and provided sound self-supporting walls which required very little scaling.

Jan 1, 1965

By J. Ribovich

The current Bureau of Mines active list of permissible explosives includes 71 brands. Eleven are gelatinous, 56 are the granular type, and four are water-gel explosives, an entirely new type of ammonium nitrate-based explosive for use in coal mines. The list of permissible blasting devices comprises five Cardox models.

Jan 1, 1973

By James V. Kelly

During the winter of 1946 and the spring of 1947, the Bureau of Mines conducted an investigation and drilling program in the vicinity of the village of Fairplay, Wis. Fifteen diamond drill holes totaling 2,457.6 feet of bore were completed. This work was part of a general study of the zinc-producing area of southwestern Wisconsin and had the particular purpose of investigating a structural trend, determined by the Federal Geological Survey, in an area some distance from known ore bodies or active mines.

Jan 1, 1948

By P. A. Richardson

The current Bureau of Mines active list of permissible explosives includes 76 brands. Eleven are gelatinous and the rest are the granular type. The list of permissible blasting devices comprises five Cardox models.

Jan 1, 1970

By Ronald A. Munson

Samples of the naturally occurring zeolites phillipsite, clinoptilolite, erionite, and chabazite have been surveyed for their gas adsorption, ion exchange, and other characteristics. Chabazite and erionite, which are generally more stable, also have higher methane adsorption capacities than do the other natural zeolites. Both natural erionite and natural chabazite are classified as small-port zeolites on the basis of their inability to adsorb chlorotrifluoromethane. In the range of 8 to 100 mesh, the adsorptive capac-ity of natural zeolites is improved only slightly by a decrease in particle size. The capacity of natural clinoptilolite to adsorb methane is increased by cation replacement by the hydrogen ion and decreased by exchange with calcium ion. Natural phillipsite, which is easily decomposed by heat, adsorbed methane to a limited extent.

Jan 1, 1973

By Steven J. Schatzel, Joseph Cervik, Gerald L. Finfinger

Gas drainage through surface bore¬holes has been the conventional means of methane control for U.S. longwall gobs. However, these vertical boreholes are becoming so costly, and the surface rights so difficult to obtain, that the Bureau of Mines is developing underground gob gas drainage as an alternate means of methane control for U.S. longwal..ls. Holes are drilled into the roof over the panel and on retreating longwalls, towards the working face from a location inby the face. As the longwall retreats, an increasing portion of the hole inter¬cepts the fracture system over the caved gob. A surface exhauster maintains a vacuum on a pipeline parelleling the panel and draws the methane mixture out of the mine. Auxiliary systems of gob gas drain¬age during longwall mining will be essen¬tial for an increasing number of coal mines. Deep and gassy mines often find ventilation insufficient for adequate dilution of methane in bleeder entries. Although this cross-measure method of degasification has been used successfully in Europe, some of the European tech¬niques cannot be directly applied to U.S. mines. This is the first study of its kind in this country.

Jan 1, 1982

By R. D. Leitch

"INTRODUCTION The general program of the investigation of coal mine drainage which the Bureau of Mines is making includes, among its many phases and objectives, a study of the fate of the acid, content of drainage after it enters natural streams, and the effect of seasonal variations on the degree of contamination of streams. Opportunity for studying these under comparatively normal conditions and variations can readily be found, but there is only a chance opportunity for studying than under extreme conditions. The unusual drought that prevailed during the summer of 1930, however, created a condition of low water favorable to a study of one of the extremes.This report gives the results of an investigation of Bennett Branch of Sinnemahoning Creek, Pa., made under this condition.ACKNOWLEDGMENTSThis work was conducted under the direction, and with the advice, of Dr. R. R. Sayers, chief, Health and. Safety Branch, and of W. p. Yant, supervising engineer, Pittsburgh Experiment Station.DESCRIPTION OF BENNETT BRANCHBennett Branch, as shown in Figure 1, is a tributary to Sinnemahoning Creek. Its source is in Huston Township, northwestern Clearfield. County, from which it flows in a general northeasterly direction through Elk County, thenceeasterly in Cameron County to Sinnoning Creek at Driftwood. The total length is about 37 miles. There are nine towns along the stream that have an average population of about 350. There is no industrial pollution other that from coal mines and very little. domestic, pollution."

Jul 1, 1931