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By Russell R. Trengove

Exploring for additional ore bodies on the property of the New Idria Quicksilver Mining Co.'s property at Idria, Calif., was done by the Bureau of Mines in cooperation with the Geological Survey. It comprised a study of the geology, mapping, and searching for additional cinnabar by diamond drilling from both surface and underground. Diamond-drill equipment was moved to the project in November 1941, and drilling was completed in.May 1942. Sixteen holes aggregating 2,580 feet were drilled. Diamond drilling by the Bureau of Mines developed information regarding ore structures that proved valuable to the operators in planning underground prospecting that led directly to the discovery of high-grade ore.

Jan 1, 1949

By Paul C. Turner

The U.S. Bureau of Mines, through an Interagency Agreement with the U.S. Army Tank-Automotive Command (TACOM), has successfully developed a steel expendable pattern casting process (EPC) for the manufacture of armorplate. The new armor is lighter and more ballistically effective than conventional rolled homogeneous armor (RHA), and costs less. An applique armor spinoff from the program was field-tested during the Gulf War. The applique armor withstood direct impacts from enemy munitions without failure.

Jan 1, 2010

By T. A. Klinefelter, R. G. Meara

N/A

Mar 1, 1943

By F. W. Woodman

N/A

Feb 1, 1943

By H. M. Thorne

Oil shale, a potential source of products presently obtained from petroleum, is found in many countries. The most extensive known deposits from the standpoint of potential shale oil in place are those in Brazil and the United States of America. Mining methods used for oil shale range from open-pit operations for shallow deposits to room-and-pillar and longwall techniques for deposits with thick overburdens. Oil shales from different sources vary greatly in the amounts and types of organic and inorganic constituents. By retorting, the organic material is converted to oil, gas, and coke. The largest percentages of oil are obtained from materials having the highest hydrogen content. Over 2,000 retorting systems have been patented, but only a few have been used industrially, and no single process seems best for all types of shales or economic conditions. Shale oils have different characteristics, depending on the source rock and method of retorting. They contain large quantities of olefinic hydrocarbons and more oxygen, nitrogen, and sulfur derivatives of hydrocarbons than most petroleums. Consequently, petroleum refining methods usually must be modified for shale oil. This is particularly true in catalytic processing. Hydrogenation, even under mild conditions, improves shale-oil refinability. Several byproducts may be obtained from both the retorting and refining steps,

Jan 1, 1964

By H. O. McDonald

The Bureau of Mines reviewed the chemical vapor deposition (CVD) literature of the group IVB, VB, and VIR elements. This review was utilized in the Bureau's research to provide erosion-, abrasion-, and corrosion-resistant coatings for valve components used in coal gasification units. This report attempts to bring together the many CVD references that have been published since 1966. Each of the group IVB, VB, and VLB metal coatings were reviewed, and some of their preparation methods, uses, and properties are given. A total of 160 references were found for the nine elements. Isotope separation, stronger steels, solar absorbers, alloys, superconductors, optical fibers, and coatings to increase the life of materials are some of the new uses for CVD.

Jan 1, 1979

By S. M. Shelton, R. B. Fisher, M. M. Fine

"INTRODUCTION The Batesville manganese district lies in the southern part of the Ozark region, mostly in Independence County but partly in Sharp, Izard, and Stone Counties of north central Arkansas.Oxides, carbonates, and silicates of manganese are found in the district. 4/ Carbonate ores have been mined from time to time, but the reserves of potentially commercial ore are chiefly black manganese oxide minerals.The district has produced manganese ore for many years. lip to and including 1933, 160,804 long tons of ferruginous manganese ore (10 to 35 percent manganese) and 140,277 long tons of metallurgical ore (35 percent or more manganese) were shipped;./ most of it was wad orThe term ""wad ore,"" used locally to designate the soft, clayey de¬posits of oxide ore, is a partial misnomer. The ores contain a soft, low-specific-gravity mineral of indefinite composition, which can be designated as wad, but coarse and fine particles of psilomelane and hausmannite, with a smaller proportion of braunite, pyrolusite, and indefinite manganese silicates, are also present. Large and small lumps of high-grade, hard manganese oxide minerals are found, frequently embedded in a soft, black matrix of fine particles of manganese oxides mixed with gangue."

Jul 1, 1942

By John E. Shelton

The growing interest in beryllium as a structural material, and its in-creased use in recent years for atomic energy application, have led both government and industry to express concern over the inadequacy of the beryllium resources in the United States and the free world. Contemplated and proposed uses for this unique material will surpass the capacity of the domestic beryllium mining industry to supply raw material, which is presently extracted from relatively small deposits by hand sorting. The need for a simple beneficiation process for beryl ores has long been recognized by the Bureau of Mines, but to date no single process has proved satisfactory for treating deposits containing a sufficient tonnage of beryl ore to warrant commercial exploitation. As a part of the Bureau's continuing effort to develop an economical recovery process, this report describes flotation research on samples of beryl-bearing pegmatites from the George Roebling mine in Connecticut, and the Colony mine in New Hampshire. The study resulted in two methods of treatment to which the ores responded reasonably well.

Jan 1, 1961

By John W. Thatcher

A demountable X-ray tube vacuum spectrograph was designed by the Bureau of Mines for the determination of long-wavelength X-ray spectra from the light elements. This instrument was operated for both secondary and combined primary-secondary excitation of the aluminum K-series. There was an increased analytical sensitivity for elements in period 3, and an indication that with improved X-ray tubes or direct election excitation of the sample, X-ray determination of elements in period 2 is also possible.

Jan 1, 1965

By B. W. Madsen

The Bureau of Mines conducted a large-scale (6.4 t), long-term (2,165 days) test to gain a better understanding of the leaching characteristics of chalcopyritic ores. An ore sample containing 0.77 pct Cu was leached in a fiberglass column by downward percolation of acidified ferric sulfate solutions. Three sets of leaching conditions were investigated: (1) ambient temperature leaching, (2) elevated temperature (50° to 60° C) leaching, and (3) elevated temperature leaching after inoculation with thermophilic bacteria. Leaching at ambient temperature resulted in a copper extraction rate of 0.44 pct per 100 days. Increasing the temperature to 50° to 60° C resulted in decreased activity of natural mesophilic bacteria, and the leaching rate decreased to 0.22 pct per 100 days. The pH was lowered from 2.0 to 1.6, and nutrient solutions that contained thermophilic bacteria were added. This procedure resulted in an increase in the ferric-to-ferrous iron ratio and an increase in the copper leaching rate. However, the increased leaching rate was not sustained, and 120 days after inoculation the bacterial activity declined, the ferrous iron content increased, and the copper leaching rate decreased.

Jan 1, 1983

By G. W. Jones

As a part of it investigations pertaining to the promotion of safety, the Bureau of Mines is investigating various means, useful for the elimination or mitigation of the explosion hazards of combustible gases encountered in mining and industry. Information has been obtained and a procedure developed whereby the explocibility of many complex, gaseous, combustible atmospheres may be calculated in a simple manner without the necessity of performing laborious laboratory experiments. In a previous publication4/ data were given and a method described whereby the limits of inflammability of gaseous mixtures, including methane, hydrogen, carbon monoxide, nitrogen, carbon dioxide, and oxygen, could be determined by calculation. The information published in that report enables one to calculate the limits of inflammability of such gases as are liberated by mine fires, gases from explosives, automobile exhaust ran, uses present after mine explosions, blast-furnace gas, and other gases containing part of or all of the above-listed constituents.

Jan 1, 1938

By R. V. Higgins

As part of a study of application of the Buckley-Leverett method to an analysis of oil-reservoir performance covering a wide range of relative permeabilities and oil saturations, a method has been devised for quickly deter-mining average water saturation at breakthrough from relative permeability data. The base for the relative permeability used in the report is either the permeability to air or the effective permeability to oil at the irreducible water saturation. The permeability to air also was used because of the large backlog of air permeabilities available to reservoir engineers. The basic data were calculated by an electronic computer and are presented in a single graph from which the point of breakthrough may be obtained. In this study the water saturation at the beginning of the depletion is the connate or interstitial or irreducible water saturation. These water saturations are considered to be synonymous and to have a practical value.

Jan 1, 1960

By Albert F. Baker

Techniques were developed and circuitry was assembled for measuring the total and volume resistances to the flow of electric current through solid specimens of anthracite. The two-, three-, and four-terminal test methods demonstrated the extreme sensitivity of resistivity to differences in anthracite characteristics and showed response to changes resulting from variations in structure, temperature, and moisture content.

Jan 1, 1966

By J. P. Capp

The Federal Bureau of Mines and the Alabama Power Company conducted an experiment in underground gasification of coal at Gorgas, Ala. involving the use of hydraulic fracturing to increase the air acceptance of a coalbed for the introduction of combustion air and removal of product gases. Air acceptance is defined as the flow rate of air which can be injected into the coalbed at 65 p.s.i.g. This was the second time the hydraulic-fracturing technique was used at Gorgas. Sand suspended in a heavy oil served as the fracturing fluid in the first experiment; in the second the sand was two to six times larger and was suspended in a water-starch gel. In addition to providing further tests of the underground-gasification process, the purpose of the second experiment was to determine the effects of the larger sand and greater volumes of a water-base fluid on (1) the extent of the fractured area, (2) the air acceptance of the coal, and (3) the rate at which a gasification path could be carbonized (linked) through the coal, and to compare these results with those of the first experiment. The coal was fractured by injecting 11,000 lb. of sand and 33,580 gal. of water and water-gel at 200 to 600 g.p.m. and 900 to 1,000 p.s.i. The fluid fractured the coal and the sand served as a propping agent to hold the cracks and crevices open. Pressures during the fracturing operation at test boreholes indicated that the fracturing fluid extended only about 150 ft. from borehole H, the point of application of the fracture. Injection of air revealed that the air acceptance of the coalbed within this e t was materially increased. On the other hand, increased air acceptance also was noted at boreholes up to 280 ft. from borehole H and at the electrolinking area 300 to 400 ft. away, indicating that the fracture effects extended considerably farther than was evident from observation. Similar effects were noted at approximately the same distances after the first hydraulic fracture.

Jan 1, 1961

By Steven R. Ruggieri

This report documents the work performed and the results obtained during the field demonstration of the Remote Sealing System at the USBM's Jenny Mine near Inez, KY in the Fall of 1978. Although various portions of the Remote Sealing System had been used on a number of prior occasions, the field demonstration at Jenny Mine marked the first use of the complete upgraded system including the use of the inert gas generating system for seal placement and the first application of the new froth foam system. The objective of the field demonstration at Jenny Mine was to demonstrate the complete system by emplacing and evaluating several complete underground seals under conditions representing those of a mine fire situation. Several critical sealing conditions were identified including: ? High entry airflow ? Standing water (1 to 2 ft) in the entry ? Flowing water (150 gal/min) ? Irregular roof ? Sealing a 4-way intersection. Four seals were successfully placed under the conditions mentioned above. The demonstration served to verify proposed techniques to handle these conditions as well as to dispel any doubts about the system's capabilities. As a result of the successful field demonstration, the Remote Sealing Equipment is now under the jurisdiction of MSHA's Mine Emergency Operation ready for a mine fire emergency.

Jan 1, 1980

1. In 2001, a total of 281 metal mining operations reported employment to the Mine Safety and Health Administration (MSHA) (down from 309 metal mines in 2000). Metal mines were the smallest mining sector, 1 comprising 1.9% of all mining operations. This was the lowest percentage of all mining sectors. • The median number of operator employees per metal mine was 17.5.2 • Gold mines comprised 43.1% (n = 121) of all metal mining operations. Other types of metal mines were copper ore (n = 37, 13.2%), iron ore (n = 27, 9.6%), and lead and/or zinc ore (n = 24, 8.5%). • Nearly 20% (n = 55) of metal mines were located in Nevada.

Jul 1, 2003

By Jr. Fish

As a part of a study of iron are resources in the Appalachians, 9 diamond drill holes aggregating 1,580.7 feet were drilled in a portion of the Butt Mountain area of northeastern Giles County, Virginia. Three hematitic sand-stone beds were intersected in the Clinton formation but only one was consistent in thickness and grade in all 9 drill holes. This bed averages 18.9 percent iron over an average thickness of 24 feet. The drill cores were logged and chemical analyses were made on 161 individual samples and 22 composite samples. Beneficiation studies were made of three composite hematitic sandstone samples each representing a separate bed containing 14.6, 19.8 and 20.0 per-cent iron. Major mineral constituents of the samples were hematite, quartz, and sericite.

Jan 1, 1967

By Frank J. Weibelt

In accordance with provisions of the Strategic Minerals Act of 1939, the Bureau of Mines surveyed the chromite occurrences in California. The Seiad Creek deposit afforded excellent opportunity for developing reserves that could be used by the nation in case of critical shortages of the mineral. Subsequently an exploration and development program was undertaken in April 1941, which was concluded in October of the same year. Work included road construction, diamond drilling, drifting and crosscutting, surface trenching, and sampling.

Jan 1, 1949

By J. H. Field

Results of studies by the Federal Bureau of Mines on a pilot-plant scale for removing hydrogen sulfide and carbonyl sulfide from gas mixtures by the hot carbonate system are given in this publication. Gases containing up to 10 pet. hydrogen sulfide and 48 grains carbonyl sulfide per 100 cu.ft. were treated. In most tests carbon dioxide also was present and was removed simultaneously with the sulfur compounds. Because the rate of absorption of hydrogen sulfide is much more rapid than that of carbon dioxide over a wide temperature range, selective removal of hydrogen sulfide occurred in the bottom section of the absorber near the point of gas entry. Hydrogen sulfide was removed to pipeline specifications with carbonate solutions by using split-stream flows in the absorber and regenerator.

Jan 1, 1960

By B. W. Naugle

Twenty-nine sole-heated-oven expansion teats were made on 9 different coals, and apparent specific-Brevity tests were made on 12 of the resultant cokes. The coals, which ranged in dry, mineral-matter-free fixed-carbon content from 58.7 to 81.1 percent, were tested over a rather wide range of moisture content and dry-coal bulk density to determine the separate effects of these variables on linear coal expansion. The experimental data support the follow expression relating "as-tested" coal bulk density, moisture content, and linear expansion, [ER = (1-MR) (1+Et) - 1; BDt] where ER = fractional expansion at a reference bulk density of 55.0 lb. of 1 percent moisture coal per cu. ft., Et = fractional expansion at Mt and BDt, MR = reference moisture content = 0.01, Mt = moisture content, "as-tested", BDR = reference bulk density = 55.0 lb. per cu, ft., BDt = bulk density, "as-tested", 1b. per cu. ft.

Jan 1, 1957