Search Documents

By John A. Organiscak

Enclosed cabs are a primary means of reducing equipment operators? silica dust exposure at surface mines. The National Institute of Occupational Safety and Health recently performed a laboratory study to evaluate which factors on an enclosed-cab filtration system are most significant. The various factors evaluated were intake filter efficiency, intake air leakage, intake filter loading, wind infiltration, use of a recirculation filter, and the use of an intake pressurization fan. The result of this laboratory testing has shown that the two most important factors for an effective filtration system on an enclosed cab were the efficiency of the intake filter and the use of a recirculation filter. A higher-efficiency intake filter considerably increased the quality of the intake air that was delivered into the enclosed cab. It also was determined that air leakage around the intake filter notice-ably reduced its air cleaning effectiveness. The second key factor is the use of a recirculation filter, which was shown to improve the air quality in the enclosed cab by six to 12.7 times more than the intake filter alone. The reason for the significant improvement was that the cab air was constantly drawn through the recirculation filter, thus continually filtering the dust out of the air.

Jan 1, 2010

By B. Demoulin, J. Fontaine, R. Gabillard, P. Degauque

To realize a radiowave communication along mine galleries a few kilometers long without repeater, we show that it is possible to use a coaxial cable bearing an important surface transfer impedance like a transmission line with an inductive coupling to the transmitter and the receiver. We determine the electrical and geometrical constants of the cable and the optimal frequency.

Jan 1, 1973

By Ralph H. Espach

In the spring of 1943, when it was evident that the Tensleep sandstone in the Elk Basin field, Wyoming and Montana, held a large reserve of petroleum, Bureau of Mines engineers obtained samples of oil from the bottom of nine wells and analyzed them for such physical characteristics as the volumes of gas in solution, saturation pressures or bubble points, shrinkage in volume caused by the release of gas from solution, expansion of the oil with decrease in pressure, and other related properties. The composition of the gas in solution in the oil was studied. The pressures and temperatures existing in the reservoir and the productivity characteristics of the oil wells were determined. The data obtained indicate that the oil in the Tensleep reservoir of the Elk Basin field has unusually varying physical characteristics, such as a saturation pressure of 1,250 pounds per square inch absolute and 490 cubic feet of gas in solution in a barrel of oil at the crest of the structure, and a saturation pressure of 530 pounds per square inch absolute and 134 cubic feet of gas in solution in a barrel of oil low on the flanks. The hydrogen sulfide content of the 6a r; in solution in the oil varies from 18 percent for oil on the crest to 5 percent for oil low on the flanks of the structure. Of even greater significance is the fact that these and other variable characteristics of the reservoir oil are related to the position of oil in the structure. Many geologists and petroleum engineers have considered all the oil in a petroleum reservoir to have uniform physical characteristics and that equilibrium conditions prevailed in all underground accumulations of oil and gas. That such is not always so is borne out by the results of the study made by the writers.

Jan 1, 1951

By X. C. Shi

Bacterial mutagenicity and mammalian cell chromosomal and DNA damage in vitro assays were performed on a diesel exhaust particulate material (DPM) standard in two preparations: as an organic solvent extract, and as an aqueous dispersion in a simulated pulmonary surfactant. U.S. National Institute for Standards and Technology DPM SRM 2975 expressed mutagenic activity in the Salmonella reversion assay, and for in vitro genotoxicity to mammalian cells as micronucleus induction and as DNA damage in both preparations: as an acetone extract of the DPM mixed into dimethylsulfoxide, and as a mixture of whole DPM in a dispersion of dipalmitoyl phosphatidyl choline. Dispersion in surfactant was used to model the conditioning of DPM depositing on the deep respiratory airways of the lung. DPM solid residue after acetone extraction was inactive when assayed as a surfactant dispersion in the micronucleus induction assay, as was surfactant dispersion of a respirable particulate carbon black. In general, a given mass of the DPM in surfactant dispersion expressed greater activity than the solvent extract of an equal mass of DPM.

Jan 1, 2009

By J. A. Stampe

In connection with its investigations of strategic minerals in the United States, the Bureau of Mines ran magnetic surveys totaling more than 533,000 linear feet at 30 deposits of magnetite in northern New Jersey. These deposits occur in a belt of granitic gneiss and in limited areas of limestone. The ore consists of magnetite accompanied by score of the following minerals: Hornblende, augite, apatite, feldspar, biotite, calcite, garnet and pyrolusite. Results of these investigations are being presented in two reports of which this is the second. The first paper, Certain. Magnetite Deposits in New Jersey, by A. L. Neumann and McHenry Mosier, was issued in April 1948 as Report of Investigations 4225.

Jan 1, 1949

By S. P. Howell

"Technical statistical study has been made of accidents in the anthracite region of Pennsylvania in which explosives were involved. The data have been taken from the accident reports in the files of the department of mines of Pennsylvania, supplemented by inquiries in the field.This study has disclosed a wealth of information regarding the nature and the cause of accidents that occurred where different means of firing shots of explosives were employed. In the anthracite region shots are fired with fuse, with squibs, and with electricity,Many of the salient features of this accident experience are illustrated in this report of investigations, and a number of recommendations are made to reduce the hazards of each of these three methods of shot firing.Experience seems to demonstrate that, under conditions in the anthracite region, electric firing of shots is substantially the safest method; that accidents wherein fuse is employed are more frequent than accidents in which electric firing is employed; and that the number of accidents when squibs are employed far exceeds those in which either fuse or electric firing is used."

Mar 1, 1930

By B. M. Bird

For several years the U.S. Bureau of Mines and the University of Washington have been cooperating, in a study of coal tabling. The first pert of the work consisted of experiments using, one of the commercial-sized coal washing tables in the laboratories of the College of Mine. As an outgrowth of this work, hindered-settling classification has been successfully applied in the tabling of coal4, and several important improvements, mainly in the riffling, have been made in the table itself. Both of these developments have resulted in increasing the rapacity and efficiency of the coal-washing table. In order to facilitate further progress in this work an investigation has been undertaken to throw more light on the mechanism of table separation. The final separation of a table is obviously the resultant of several operations; namely, stratification, removal of the top strata or parts of them as washed coal by the cross-flowing water, and removal of the bottom strata or parts of

Jan 1, 1929

By Jon K. Ahlness

The Bureau of Mines investigated technologies for testing the integrity of in situ leach mining wells, as required by environmental regulations. To test for leaks, inflatable packers were used to seal the well casing. Laboratory testing determined that the packers could contain a casing pressure up to 50 to 60 psi (345 to 414 kPa) less than the packer inflation pressure. Single-and double-packer configurations were successfully field-tested in 32 wells ranging from 500 to 530 ft (153 to 162 m) in depth. A rigid pipeline and a hoist truck were used to run the packers in and out of the wells for the double-packer tests, which averaged 2-1/4 h each. In an effort to decrease the time of the rigid-pipe double-packer test. a self-contained trailer-mounted test system was designed and built. It utilizes a winch and steel cable to run the packers in and out of the well and high-pressure nylon tubing for packer inflation. This system was successfully field-tested in eight wells averaging 650 ft (198 m) in depth and resulted in a time savings of 13 pct and an operator-hour reduction of 42 pct.

Jan 1, 1985

By A. D. Hahn

This report describes and gives the results of an examination by the Federal Bureau of Mines of ilmenite-bearing placer sand deposits in the 24-mile long valley of Otter Creek, Kiowa and Tillman Counties, Okla. Drilling and sampling was completed in three periods between October 1956 and September 1957. Mineralogic studies and mineral-dressing tests on recovery of ilmenite and other heavy minerals from composited samples of the sands were made in Bureau of Mines laboratories at Rolla, Mo., in 1957 and early 1958. Otter Creek rises in and drains the southwestern extremity of the Wichita Mountains, which are represented locally by knolls and ridges of gabbro and granite surrounded by plains floored with flat-lying Permian red beds. The valley fill consists of a basal sand-clay component, derived from weathering of the igneous rocks, and an overlying silt-clay alluvium. Ilmenite is present in significant quantity and recoverable grain size only in the basal sand-clay.

Jan 1, 1960

By G. S. Scott, G. W. Jones

"INTRODUCTION In the course of the investigation the Bureau of Mines is carrying on to determine the causes, behavior, a. control of mine fires, the detection of incipient heating underground in the mines and above ground in refuse banks has received consideration.Many of the anthracite fires have been active for years and have progressed considerable distances free their original source.Some of the fires are in inaccessible territory, and it is often impossible to determine with any degree of accuracy their exact location or even the veins of coal that are afire, especially when the fire is in the upper strata and when it is impossible to go underground because of flooded conditions or the presence of an irrespirable atmosphere.In such cases, the only means by which the trend of a fire may be ascertained (as a result of any fire-fighting methods that may have been employed) are the sampling, exanination, and interpretation of the gaseous products coming from the fire area. The most important information desired is to know whether the temperature in the heated area is increasing or decreasing and to determine whether a fire that has been sealed is cooling down to normal mine temperatures or is maintaining its heat or is increasing in intensity due to infiltration of outside air.Interpretation of the analyses of gaseous products from refuse banks on the surface also should be of value in combating such fires. Refuse bank fires, with the additional danger of starting an underground fire through ignition of the outcrop, are by no means unknown in the anthracite coal region, and the causes of such fires are not always apparent. In a few cases the causes have been strongly suggestive of spontaneous origin."

Jun 1, 1938

By R. M. Gooding

This paper presents a short history of the production of mineral-energy fuels and energy from waterpower in the United States, with brief discussions of the utilization of each of the fuels and hydropower, and a look at fuels competition and interchangeability. Basic data, in figures and tables, are brought together in this publication for the production of coal in the United States from 1800 to 1960, for crude petroleum, natural gas liquids, and natural gas from 1859 to 1960, and for hydropower since 1900. Production for each segment of the fuels complex in the principal producing States from 1946 to 1960 is shown. Data are not included for consumption as such or for imports and exports.

Jan 1, 1963

By R. J. Matetic

The National Institute for Occupational Safety and Health (NIOSH) has recognized that Noise-Induced Hearing Loss (NIHL) is the most common occupational illness in the United States. The use of heavy equipment, the drilling of rock, and the confined work environment are some of the factors that contribute to high levels of noise exposure to workers in the mining industry. Every day 80% of the nation’s miners go to work in an environment where the time weighted average (TWA) exceeds 85 dBA. Moreover, 25% of the miners are exposed to a TWA noise level that exceeds 90 dBA, the Permissible Exposure Limit (PEL). Furthermore, a NIOSH analysis of a large sample of audiograms showed that at age 50 approximately 90% of coal miners and 49% of metal/non-metal miners have a hearing impairment. By contrast, only 10% of the non-occupational-noise exposed population has a hearing impairment at age 50 (Franks, 1997) (Stephenson, 1998). Simply stated, the majority of miners have a hearing loss by the time they retire. While NIHL is the most common occupational disease in this country, this problem is especially acute among workers in the mining industry. There are several barriers to reducing NIHL in the mining industry. These include: gaps in knowledge of noise dose/source relationships, the unavailability of effective noise controls, and needs for worker education and worker empowerment. A related issue is the difficulty of communication in noisy workplaces by both hearing impaired and normal hearing workers. The Pittsburgh Research Laboratory (PRL) at NIOSH has strategically developed a hearing loss prevention program for overcoming these respective barriers in an attempt to reduce NIHL in the mining industry. This paper provides an overview of the research program being conducted at the PRL.

By E. J. Kloos

The Bureau of Mines devised a new machine-test method for measuring carbon dioxide inspired by a wearer of self-contained breathing apparatus. The new method compares favorably in speed and precision with standard man-tests in which the apparatus is tested while actually worn, and is scheduled for use in future approval tests for facepiece carbon dioxide 'measurements. However, man-tests will still be used to measure the efficiency of the carbon dioxide sorbent materials in closed-circuit breathing apparatus.

Jan 1, 1966

By R. H. Storch

The work described in this report was part of a Bureau of Mines program to appraise the titanium-mineral resources of Idaho. Part of the program included churn drilling of alluvial deposits that previous preliminary testing, primarily for rare minerals, had indicated to be potential sources of titanium minerals. The first spot churn drilling began in the Deadwood placer area, Valley County, Idaho, in July 1956 to determine both the amount and grade of the ilmenite, FeTi03. Ten holes, ranging in depth from 6 to 40 feet and aggregating 251 feet, were drilled; 54 samples were taken. The samples were sent to the Spokane field laboratory for concentration and visual estimation of the amounts of the more common minerals in the heavy sand concentrates. For specific determinations samples from each drill hole were composited and shipped to the Bureau of Mines laboratory in Albany, Oreg., where petrographic, quantitative X-ray spectrographic, and chemical analyses were made.

Jan 1, 1958

By Larry P. Jackson

As part of the current research effort in shale-oil chemistry conducted by the Federal Bureau of Mines, reduced chlorophyllins were prepared and pyrolyzed in an effort to identify the role of plant pigments and their decomposition products in the nitrogenous compounds found in the product of oil-shale pyrolysis. The properties of the chlorophyllin pyrolysates were related to the composition of the reduced chlorophyllins with particular emphasis on the amount and types of nitrogen compounds formed. A comparison based on the types of nitrogen compounds present was made betvJeen shale oil and the chlorophyll in pyrolsates. In order to make this comparison, a sample of shale-oil light distillate was separated into polar and nonpolar fractions, and a careful examination of the polar fraction was conducted to obtain an accurate picture of the types of nitrogen compounds present. The information gathered from these studies was used to evaluate reduced chlorophyllin as a model of oil-shale kerogen insofar as the production of nitrogen compounds was concerned. The results indicate that the reduced chlorophyllin does yield nitrogen products which are directly related to the nitrogenous compounds in shale oil, and it therefore represents a good model of shale-oil kerogen.

Jan 1, 1975

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, Ark., has been given in Report of Investigations 4251. In this volume and in a series of Reports of Investigations immediately following the factual data obtained during the project are reported. 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 und name are shown on the appropriate half-township map.-The description of each half township is followed by a description of each deposit developed in that half township. The 14 half-township maps and 77 detail maps of the bauxite deposits in this eeri88 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 (R. I. 4251). 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 tor each half township is given with the discussion covering that area.

Jan 1, 1948

By Harold L. Rhodes

The Bureau of Mines has developed a quantitative method to determine water vapor in helium in the range of 0.1 to 15 ppm by volume. This method uses the quantitative chemical reaction of H20 with CaH2, which produces 1 mole of hydrogen for each mole of H20 in the sample. A gas chromatograph is then used to determine the concentration of hydrogen in the product. The precision of the H20 analysis is ±0.05 ppm at a concentration of 1 ppm. This method is used to calibrate a commercial platinum-phosphorus pentoxide (Pt-P205) electrolytic water vapor analyzer that has an improved inlet system and digital voltmeter readout.

Jan 1, 1981

By Thomas C. Miller, Rudolph Sporcic

A relatively simple and inexpensive encapsulated hydraulic device has been developed by the Bureau of Mines to facilitate study of coal bumps , and to measure pressure changes in a coalbed as it is subjected to roof loading during mining . Construction of the device and application techniques are described . Preliminary feasibility tests in the laboratory and field indicate that the device responds satisfactorily to pressure changes in coal created by roof loading .

Jan 1, 1964

By D. J. Singleton

Erosion corrosion of 12 alloys in phosphoric acid waste water was studied by the Bureau of Mines. Tests were conducted on oblate spheroids or cylindrical specimens in 12-and 60-cm-diam ball mills by grinding phosphate rock in gypsum pond water with a starting pH of 1.6. For comparison, tests were conducted while grinding phosphate rock in plain water. Static corrosion tests in gypsum pond water also were conducted. For all alloys, the wear by erosion-corrosion (milling with gypsum pond water) was greater than the sum of erosion (milling with water) plus static corrosion. Erosion-corrosion wear was about 1,500 to 3,000 mpy for the alloyed white cast irons, 1,000 to 1,400 mpy for commercial steel ball material and type 316 stainless steel, and 600 to 900 mpy for nickel-base alloys and a high-manganese, nitrided stainless steel. Alloy costs per unit of phosphate rock 'processed favor a low-alloy, high-carbon steel or a high-manganese, nitrided stainless steel.

Jan 1, 1985

By Robert W. Smith

Computation of the thermodynamic properties of the reaction products in the deflagration of explosive gas mixtures has been a most valuable guide regarding the possible kinetic mechanisms of homogeneous combustion processes. Knowledge of the physically possible end states is indispensable for understanding observed deviations from equilibrium in heterogeneous combustion. However such information on dust flames is entirely lacking. To complement a Federal Bureau of Mines study of stationary graphite dust flames burning in pure oxygen,6/ this report gives examples, at atmospheric pressure and room temperature, of composition profiles in an idealized oxygen-dust flame, with both mass and enthalpy being preserved. Similar profiles can be obtained from the data of the paper for elevated temperature and pressure.

Jan 1, 1960