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By M. V. Potter

"In nearly all fields of investigation, research laboratories and routine testing laboratories encounter problems in which the primary determinations involved in the study require the measurement of mechanical vibrations or motions. These vibrations,may be of an oscillatory nature covering frequencies from a few cycles per second up to hundreds of Kilocycles per second, or they may be more or less uniform study nations occurring at rather slow rates. In electrical, or mechanical methods. In the optical case the to cause the deflection of a light beam such that the motion of the mechanican system of the beam can be determined, then by direct the by direct observation on a suitable scale or by recording it’s the electrical methods the motions can be made to changes in resistance, capacity or inductance proportion to the mechanical displacement or electromagnetic means can used to generate directly a voltage that will be porpertuial to the instantaneous vicinity of the vibrations. Other devices are used in a special instance, also but in any cause the electrical methods produce a current that is an electrical counterpart of the mechanical motion, and the motion can then be studied by direct measurements of the current or by recording the current on suitable recording meters or oscillography. Mechanical methods are used in some instance but are generally not as convenient nor as flexible as the optical and electrical methods."

Feb 1, 1943

By Forrest T. Moyer, Nina L. Jones, Mary B. McNair, Virginia C. Berté

To keep the mineral and allied industries informed of trends in the causes of accidents, and to point out the need for corrective measures, the Bueau of Mines collects, analyzes, and periodically publishes health and safety statistics. This report includes data for 1963 on injury experience, with related employment statistics, at coal mines in the United States. These data are presented in tabular form under the following headings:

Aug 1, 1965

By Michael A. Trevits

During the time period from 1990-2007, there were 1601 reportable fires that occurred in the U.S. mining industry (an average of 89 fires per year). The leading causes of U.S. mine fires include flame cutting and welding operations, frictional heating and ignitions, electrical shorts, mobile equipment malfunctions, and spontaneous combustion. The National Institute for Occupational Safety and Health (NIOSH) is conducting a program of research addressing metal/nonmetal and coal mine fire prevention, detection, management and suppression. In the metal/nonmetal area, work was focused on technology transfer and training, and research to reduce the number of mobile equipment fires and their hazards. In the coal arena, research is underway to determine the root cause of cutting and welding-related fires and to evaluate the effects of ventilation schemes relative to the spontaneous combustion risk in longwall mines. Relative to fire management, research is ongoing on remote mine seal installation and remote mine fire suppression technologies. Finally, research is continuing to develop comprehensive and usable smoke management techniques and to develop mine fire growth models, propagation, and suppression. This paper presents a summary of some of the mine fire research and provides an overview of the next phase of the NIOSH mine fire research program.

Jan 1, 2010

By McHenry Mosier

Although local conditions at each mining property affect the percentage of increase in drilling speed for a given reduction in gage of bit, the results of drilling tests conducted at the Mount Weather testing adit show such a large advantage in favor of the smaller gages that they should be indicative of the possibilities at most mines. GENERAL DISCUSSION Although it is common knowledge among miners that drilling speed ill- creases with reduction in gage of bit, the large amount o this increase is not so universally realized, A recent Bureau of Mines4/ survey of drilling practices in 28 metal mines showed that the maximum gage of starters is 3 inches and that at 50 percent of the mines starters are 2-1/4 inches or larger, Because this size appears too large for conditions at most' mines where abrasion is moderate and where powder distribution permits, the use of smaller bits presents a favorable opportunity for reducing drilling costs.

Jan 1, 1939

By W. H. Young, R. L. Anderson

"Physical conditions, such as thickness and character of the coal seam, dip or pitch of the seam, depth of cover, character of roof and overlying strata, mine water, etc., affect the productivity in bituminous-coal mining. Thickness of the coal seam being mined is probably the most important single item that determines whether the output per man per day shall be low or high; however, in strip mining the depth of cover or overburden to be moved is of equal importance.Bituminous coal is mined today from seams of exceedingly variable thickness - less than 2 feet to more than 50 feet; however, a large majority of the mines are producing .coal from seams 3 to 6 feet thick. The average thickness of the coal seams mined in the United States has not changed materially in the past 25 years. The average seam thickness for all bituminous-coal mines was 63 inches in 1920 4/ and 65 inches in 19)45. As thick seams have been exhausted in the older fields, other thick seams, have been opened in the newer fields.Productivity increased from 4 net tons per man per day in 1920 to 5.78 in 1945. This 45 percent increase in productivity resulted from increased mechanization. The percentage of underground production represented by coal cut by machines increased from 61 in 1920 to 91 in 1945 Mechanical loading increased from less than 1 percent of underground production in 1920 to 56 percent in 1945, and strip mining increased from less than 2 percent to 19 percent of the total production during the same period."

Dec 1, 1947

By H. A. Doerner

For the past three or four years attention has been attracted to the deposits of lead vanadate in the Goodsprings , Nevada , district . Some ore running as high as 9 per cent 205 has been produced , but most of it runs from 0.5 to 3 per cent . Only a little ore , and that of the richer sort , has been shipped , since the low- grade ore will not stend the cost of shipment and no concentration mill has been available . Preliminary experiments indicate that chemical treatment of the low- grade ore without concentration is not feasible . Its treatment therefore involves two distinct problems ; first , mechanical concentration ; and second , a smelting or chemical treatment to obtain the lead and vanadium in marketable form . Upon this basis the work has been conducted . The writer wishes to acknowledge the excellent work done by J. T. Norton and Virgil Miller on table concentration and by J. E. Conley , who suggested and did preliminary work on the direct smelting method . Many helpful suggestions were received from Dr. S. C. Lind and John Gross of the Bureau of Mines . The ores were furnished by Mr. Frank Williams and Mr. James Ewing .

Jan 1, 1923

By W. L. Crentz

San Juan County, which occupies the extreme northwest corner of New Mexico, contains large reserves of coal in the Fruitland formation and in the Menefee formation of the Mesaverde group. The coals have bright luster, are brittle, and break easily in handling. All mines sampled are in the La Plata-Fruitland and Rio Chaco districts of the Durango-Gallup coal field. This large area, all within San Juan County, contains numerous coal beds 5 to 15 feet thick. Ellis2/ mentions the Carbonero (Fruitland in this report) bed in the La Plata-Fruitland district attaining a thickness of 36 feet. This bed has been correlated with the Carbonero bed, formerly mined at Carbon Junction, near Durango, Colo. During the field investigation covered by this report, no operating mine in the Fruitland bed was working a bed thickness of more than 15 feet.

Jan 1, 1957

By R. F. Kendall

Only a limited number of mass and infrared reference spectra of high purity unsaturated hydrocarbons and oxygenates are presently available in the literature. To aid Bureau of Mines research programs requiring such references, 64 mass spectra and 70 infrared spectra were obtained and are reported. The individual compounds, acquired from commercial sources, were purified by preparatory gas chromatography. Purity determinations were made using a combination of analytical gas chromatography, microhydrogenation, and catalytic deoxygenation. These spectra will aid spectroscopists in the identification of compounds of the types reported.

Jan 1, 1966

By Connie S. Musulin

The Bureau of Mines conducted an experiment at Exxon Mineral Co.'s Buffalo Shaft Operation to determine the time required for radon concentrations to return to a base average after fan shutdowns. Shutdown times ranging from 5 min to 16 hr were evaluated. An equation was derived to calculate a ratio that determines the time required for the radon concentration to return to the average level that existed in the mine prior to shutdown. For fan shutdowns of 15 min or more, underground personnel should be evacuated to areas with natural downcast ventilation. For shutdowns of less than 1 hr, personnel should not return to the working area until the elapsed time is four times the shutdown, or until the working area is resampled and found safe. If the mine is not in production during weekends, the downcast fans can be turned off .from midnight Friday until 4 p.m. Sunday, and the radon daughter concentration should be below 1 WL throughout the mine by the start of the shift Monday. This fan shutdown would conserve energy and save the mining company an estimated $21,000 each year.

Jan 1, 1982

By Foster Fraas

In the separation of a component from a mixture , two fractions are obtained , one containing a high - percentage composition of the component and the other a low - percentage composition . The high - percentage fraction is frequently called the concentrate and the low - percentage fraction the tailing . In many separation processes the recovery is not complete , and the composition of the concentrate decreases as the recovery of the component, which is concentrated , increases . It is this particular class of separations to which this paper is confined .

Oct 1, 1942

By Don Steffa

Drift mining, according to California mining terminology - and it is distinctly a California development - is the blocking out and extraction (breasting) of the auriferous gravels of an ancient buried stream either through tunnels, inclines, or shafts; it is one of the minor divisions of the larger classification known as placer mining. The contribution of each of these divisions and of lode mining to the gross production of gold in California totals as follows:3 [ ] The total amount of gold recovered from the placers of California from 1848, when Marshall discovered the precious metal in the mill race at Coloma, to 1928, was $1,226,515,404. The same period saw a total gold production from all operations of $1,823,562,360.

Jan 1, 1932

By Liming Yuan

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Jan 1, 2009

By Thomas M. Barczak

This U.S. Bureau of Mines study evaluates factors that influence longwall support and strata interaction. The longwall system is composed of an immediate and main roof structure and three supporting foundations: longwall panel, powered roof supports, and gob waste. The main roof forms a structure that is generally supported by all three foundations, while the immediate roof acts as a beam that cantilevers from the coal face to the powered support. In most cases, shield loading involves a complex interaction of both main roof and immediate roof behavior and is a combination of loads produced from convergence of the main roof and displacements of the immediate roof caused by deformations of the cantilevered roof beam. Since the shield stiffness remains constant for all leg pressures and main roof convergence is irresistible in terms of shield capacity, the shield must be able to control the behavior of the immediate roof or floor structure for shield loading to be sensitive to setting pressures. If the goal is to minimize total shield loading, any active setting force must be offset by reduced passive shield loading to justify the active setting loads. Field data sumest that the typical reductions in passive loading do not justify the required increases in setting pressure in some applications.

Jan 1, 2010

By G. R. Strimbeck

This is a report on experimental work on development of a gasification process operating at near atmospheric pressures and using finely pulverized coal entrained in oxygen and steam. The gasifier was designed by The Babcock and Wilcox Co. in cooperation with engineers of the Bureau of Mines Morgantown station. The test work discussed in this report covers the first 34 tests made in the pilot plant in which a strongly coking Sewickley-bed coal, ground to either 70 or 90 percent through a 200-mesh screen, was used.

Jan 1, 1954

By Clyde M. Pearce

The Lake Superior iron-mining district includes parts of the States of Michigan, Minnesota, and Wisconsin. The laws of each State provide for an industrial commission and for inspection of mines. The following extract from the General Orders on Mines, effective October 25, 1937, issued by the Industrial Commission of Wisconsin, is the only reference to the use of safety catches on mine cages or skips found in the laws and regulations in the Lake Superior iron-mining district: Order 316 - Cages for Hoisting Men. (c) Sides, Gates, and Safety Catches. ***Every cage shall be provided with safety catches of sufficient strength to hold the cage with its maximum load at any point in the event the hoisting cable should break. (d) Testing Safety Catches. The safety catches of cages and skips used to hoist men shall be kept well oiled and in good working order. They shall be tested at least once each month by tying up the cage or skip with hemp rope, lowering a few feet of hoisting cable on top of cage, then cutting the hemp rope, provided that any other system of testing, which is equally effective, may be used.

Jan 1, 1945

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, Arkansas 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 tenth. 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 which 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 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

To evaluate the potential for dust reduction, during blasthole drilling, of water or foam applied directly into the drill hole. Approach The Bureau of Mines tested a through-the-drill-steel water and foam injection technique in two noncoal mines to evaluate the method's potential for greater dust reduction. The tests were performed by drilling a series of blastholes for an entire face (a 90 minute time-period). For the first 45 minutes of drilling, foam or water was applied through the drill steel. Blowing ventilation was supplied to the entry about 50 feet from the face. The dust concentration measurements were made by a Real-Time Aerosol Monitor (RAM-I), and the data were read out on a strip chart recorder. The evaluation test results showed that the water or foam injection technique, when used on localized dust sources, can be an extremely effective dust control method. Small amounts of water used in this method have also allowed it flexibility to be used in water-soluble ores such as salt, gypsum, anhydrite, and trona. How The System Works Water or foam is mixed with compressed air (approximately 100-120 psi) with suitable metering systems and forced through the drill steel into the blast hole at the point of dust generation. Because the water or foam is applied at the source, minimal quantities of liquid are needed (0.2 to 0.6 gpm). These low flowrates are sufficient to just moisten the dust emerging from the blast hole, thus eliminating a major source of airborne dust. The wet drilling procedure also eliminates a second source of dust. With dry drilling, the dust from the blast hole falls to the floor. Since this can be a 15-ft drop or more, the impact can send the dust billowing up from the floor, adding to the airborne dust. With wet drilling, the moistened dust merely dribbles down the face.

Jan 1, 1982

By Neal M. Muir

The increasing demand for iron ores prompted the Bureau of Mines to investigate the sources of past production in Kentucky to determine whether reserves of usable ore still exist. Preliminary investigation showed that the holdings of the Rose Run Co. were the most promising, inasmuch as the deposit had not been exhausted by past mining and the property was near railroad facilities and but 80 miles from the blast furnaces at Ashland, Ky. The Bureau conducted a churn-drilling and sampling program to investigate the depth, thickness, and iron content of the ore beds so that they might be evaluated as a possible reserve of low-grade iron ores. The Rose Run area in Bath County, Ky., was explored by 74 churn-drill holes totaling 2,059.4 feet of drilling and 4 cuts and test pits. Fifty-seven drill holes and the four test pits penetrated the ore bed at an average depth of 22 feet. The bed had an average thickness of 2.54 feet. Analyses show that the calcium and magnesium carbonate content is more than sufficient to flux the silica and provides an excess that needs an admixture with other siliceous iron ores.

Jan 1, 1950

By O. C. Blade

This report on the properties of motor fuels sold through service stations in the United States was made in accordance with a cooperative agreement between the American Petroleum Institute, and the Bureau of Mines of the United States Department of the Interior. This paper is a continuation of a series made in cooperation with the Coordinating Fuel Research (CFR) Committee of the Coordinating Research Council (CRC), Inc. The first of this series of reports presented data on motor gasolines sold during the winter of 1935-36, and succeeding reports described motor gasolines sold during the summers and winters to and including the summer of 1941. No reports were made on motor gasolines sold during the winter of 1941-42 and during the summer of 1942. However, starting with the winter of 1942-43, the semiannual reports were resumed

Jan 1, 1948

By O. C. Blade

This report on the properties of motor fuels sold through service stations in the United States was made in accordance with a cooperative agreement between the American Petroleum Institute and the Bureau of Mines of the United States Department of the Interior. This paper is a continuation of a series made in cooperation with the Coordinating Fuel Research (CPR) Committee of the Coordinating Research Council (CRC), Inc. The first of this series of reports presented data on motor gasolines sold during the winter of 1935-36, and succeeding reports described motor gasolines sold during the summers and winters to and including the summer of 1941. No reports were made on motor gasolines sold during the winter of 1941-42 and during the summer of 1942. However, starting with the winter of 1942-43, the semiannual reports were resumed.

Jan 1, 1949