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By M. D. Marshall

A remote heat-activated stench gas/tracer gas mine alarm system was developed to reduce the time between fire detection and personnel notification. The stench gas/ tracer gas system contains ethyl mercaptan for personnel warning and a fluorocarbon for tracer gas detection by instrumentation. A system was also developed which can be interfaced with multiplex mine phones. In-mine tests were conducted and several systems are presently installed in a hard rock mine.

Jan 1, 1983

By O. C. Blade

This survey report, the first for this type of fuel, is issued to provide information on the characteristics of the burner-fuel oils now manufactured for sale. Reports of surveys of diesel fuel, conducted under a cooperative agreement between the American Petroleum Institute and the Bureau of Mines, United States Deportment of the Interior, have been published annually since 1950.2/ This survey of burner-fuel oils is similar to the diesel-fuel surveys In pattern and has been conducted under an extension of the same agreement at the request of the Oil-Heat Institute of America and the petroleum industry. It is not intended to conflict with the diesel-fuel survey but rather to supplement it. Burner-fuel oils, also specifically referred to as heating oil, range oil, furnace oil, "Bunker C," and fuel oil, are sold in increasing volumes for use in this country and for export. Sales of all grades of fuel oil in the United States have increased from 340 million barrels in 1926Y to over a billion barrels per year. 4/ Distillate fuel oil sales, in proportion to total fuel-oil volume sold, increased from 42 percent in 1950 to 50 percent in 1954. Sales of distillate and the heavier residual oils during recent years are shown: [ ] It must be realized that the data given are not accurate indications of the use of these materials as burner fuels. Some burner fuel, used as range oil, is kerosine, which is not included above. A large volume of fuel oil--approximately 30 percent of the distillate type and some residual fuel oil--is sold as diesel fuel. Smaller

Jan 1, 1955

By William L. Crentz

In the past, Westmoreland County together with Fayette County produced about one-third of the bituminous coal mined in Pennsylvania. The Pittsburgh bed in Westmoreland County has furnished enormous quantities of coal to the by-product and beehive ovens, gas-manufacturing plants, and general industrial manufacturers over a wide area until about 20 years ago. Little attention was paid to the thinner beds because of the superior quality of the Pittsburgh. The approaching exhaustion of Pittsburgh coal will require accelerated-exploitation of these coals if Westmoreland County is to continue as an important source of bituminous coal, Much of the Pittsburgh coal in Westmoreland County is low-sulfur and requires no mechanical cleaning for the preparation of a metallurgical fuel. Even those areas where the sulfur percentage increased to a maximum of about 2 percent, a relatively easy washing operation usually produced a cleaned coal, which found ready acceptance by the coke industry. Davis reported the remaining recoverable reserves of the .Pittsburgh bed in Westmoreland County to be 255,439,000 tons as of January 1, 1937. Since that date, more than 100,000,000 tons of Pittsburgh coal has been extracted so that the time is not too distant when this important coal bed will be depleted. A study of the Pittsburgh bed in Westmoreland -County has not been made a part of this report as the remaining reserves of the coal can be used in coke making with a, minimum of preparation. The production from the Upper 'Freeport bed will increase as the supply of coal from the Pittsburgh bed diminishes, and as of the present time it supplies a substantial proportion of the county's coal output.

Jan 1, 1951

By B. K. Cantrell, K. L. Rubow

"The US Bureau of Mines and the University of Minnesota have developed design and performance criteria for a personal diesel exhaust aerosol sampler for underground coal mines. These are based on the premise that size can be used to separate diesel exhaust aerosol, which is mostly submicron in size, from coal dust aerosol, which is mostly greater than a micron in size. The sampler has three stages: a respirable aerosol preclassifier, a 0.8-um aerodynamic diameter inertial impactor to collect mineral dust and a final filter to collect the diesel aerosol. Using a sample flow rate of 2 L/min and gravimetric analysis to within 0.1 mg, the measure sub-0.8 um diesel aerosol has an a-priori limit of detection of 0.3 mg/m3.A miner working in an underground coal mine with diesel equipment is exposed to a wide array of pollutants from the diesel exhaust. These include CO, CO2. NO, NO2, SO2, diesel exhaust aerosol, and a variety of hydrocarbon compounds. A quantitative definition of the health risk resulting from these exposures remains elusive. During the past several years, though, progress has been made in defining the problem.Results from epidemiological studies by Garshick et al. (1988 ), animal inhalation studies by Mauderly eta). (1986), Iwai et al. (1986), and Brightwell et al. (1986) and in vitro studies by Lewtas et al. (1986) have provided sufficient data for the National Institute of Occupational Safety and Health (NOSH) to recommend that ""whole diesel exhaust be regarded as a 'potential occupational carcinogen,' as defined in the Cancer Policy of the Occupational Safety and Health Administration"" (NIOSH, 1988). NIOSH further stated that ""though the excess risk of cancer in diesel-exhaust-exposed workers has not been quantitatively estimated, it is logical to assume that reduction in exposure to diesel exhaust in the workplace would reduce the excess risk.""The Mine Safety and Health Administration (MSHA) has also been directed by an advisory committee to establish a diesel exhaust aerosol standard and to establish regulations to minimize exposure to diesel pollutants in underground coal mines (MSHA,1988). Both reports point out the need for development of measurement techniques for respirable diesel aerosol.In the past four years, the US Bureau of Mines (Cantrell,1987 and Cantrell, et al. 1987), in cooperation with Marple, et al. (1986), at the University of Minnesota's Particle TechnologyLaboratory (PTL), have studied the use of size-selective sampling techniques to measure the mass concentration of diesel aerosol in underground coal mines. Results from these studies have been used to develop design and performance criteria for a personal diesel exhaust aerosol sampler for use in underground coal mines.These criteria are based on the premise that size-selectivesampling techniques,can be used to separate diesel exhaust aerosol, which is predominantly submicron in size, from coal dust aerosol, which is mostly greater than a micron in size. In addition to the performance criteria, this paper discusses the laboratory and field test data used to develop the criteria."

Mar 1, 1992

By G. L. Oldright

This paper is the second of a series that is to appear on smelting in the lead blast furnace. The objects of this investigation are to determine the conditions obtaining within the blast furnace by direct experimentation, and to correlate the behavior of the furnace at various times with the main factors governing the operation of the blast furnace, and metallurgical losses. The writers wish to express their appreciation to the management of the International Smelting Company at Tooele. Utah, for their kind cooperation which made possible the assembling of these data.

Jan 1, 1929

By R. J. SHAW

Oil shale has been defined as, "a compact, laminated rock of sedimentary origin yielding over 35 percent of ash and containing organic matter that yields oil when distilled but not appreciably when extracted with the ordinary solvents for petroleum." The oil-yielding organic matter in oil shale, commonly called kerogen, decomposes upon application of heat to form bituminous materials that are soluble in organic solvents and may be extracted from the inorganic residue. However, separation usually is accomplished by continuing the heating and thereby cracking the primary bitumens to gas and oil, which distill, leaving a carbonaceous material on the mineral residue. It has been suggested that this conversion takes place only at relatively high temperatures - 750°F or higher. On the other hand, other workers have found that transformation may take place to some extent at temperatures as low as 400°F. In either a solvent extraction or a destructive distillation process for separating organic material from the inorganic portion of oil shale, the quantity of heat required to raise the temperature of the oil shale sufficiently to induce a satisfactory rate of conversion of kerogen to oil is important in determining the design of an economical process. Likewise, the quantity of heat recoverable from a spent shale is important in determining the overall heat balance of the process. Published data on the specific heat of American oil shales are meager. Gavin and Sharp present data for two samples of Colorado oil shale, one from near DeBeque and one from Parachute Creek, and for a sample of spent shale over a temperature range of 68°F to 1940°F. McKee and Lydor present data on the specific heat of two samples of oil shale from near DeBeque, Colorado. Additional thermal data on various grades of oil shale over a wider range of temperature are needed in order to apply sound engineering practices to the design of equipment for processing oil shale.

Nov 1, 1947

By S. H. Ash

THE INVESTIGATION of barrier pillars in the Western Middle field is part of the comprehensive study of the mine-water problem in the anthra¬cite region of Pennsylvania by the Federal Bureau of Mines (1, 2, 5, 6, 7, 8,9,10,11,1,2,15,16).8 The Western Middle field is in Schuylkill, Columbia, and Northumberland Counties in eastern Pennsylvania. It has an area of 120 square miles, is 42 miles long from Delano on the east to Trevorton on the west, and is 2 to 5 miles wide. In the Western Middle field are 58 underground water pools containing 38 billion gallons of water (5). Some of the pools overflow to the surface, and the water from others seeps into adjacent mines through permeable barrier pillars separating them from abandoned mines. Several active mines are interconnected to workings in abandoned mines, which are partly filled with water. These mines are separated by barrier pillars that are considered effective only below the altitude of the connections. In some abandoned mines, pumping stations maintain the water at altitudes where the hydrostatic pressure against the barrier pillars is not excessive and does not endanger adjacent active mines. If water in these abandoned mines is allowed to rise to where it can overflow into the active mines, it must be pumped from the active mines at lower altitudes; this materially increases the cost of pumping. It is estimated that from 1944 to 1948 approximately 30 percent of the water pumped to the surface was from abandoned mines.

Jan 1, 1953

By W. C. Holliman

This report on the characteristics of commercial aviation gasolines is one of a series of such reports. It presents compilations of' inspection data furnished on their products by 15 manufacturers of commercial grades of aviation gasoline and special data obtained in Bureau of Mines laboratories on 68 samples of these gasolines. Data are presented for 18 samples of grade 80, 20 of grade 91/98, 21 of grade100/130, and 9 of grade 115/145 aviation fuels. The gasolines are designated January 1948 production, although some of the samples actually were produced at a later date.

Jan 1, 1948

By E. D. Gardner

This paper discusses prospecting for lode gold and lists the principal lags and. regulations pertaining to locating; lode claims on public lands. It is a preprint of a part of a bulletin being prepared by the United States Bureau o Mines entitled "Equipping, Developing and Operating Small Gold Mines". The increased interest in gold mining manifested during the past few years (1932-1935) bas stimulated prospecting. Many adventurers have taken to the field to search for now gold deposits. A. large percentage of them have had no previous experience in prospecting for lode gold; this paper has been written with the tope that it might assist these newcomers.

Jan 1, 1935

By Will H. Coghill

This paper on milling methods and costs at a flat river (Mo.), mill is one of a series of information circulars on milling methods and costs which is being prepared by the United States Bureau of Mines, The mill under consideration treats 5,000 tons of load ore daily by table concentration and flotation. It is 25 years old, and yet it is a new mill. Research has been in continual progress at the plant since its beginning, and accordingly a day never passes without a record of change for advancement. The changes have been so orderly that no evidence of obsolete equipment remains.

Jan 1, 1932

By Kenneth E. Hjelmstad

In situ leach mining operations often encounter difficulty maintaining adequate leach solution flow into the are formation. Swelling and dis-persion of clay particles in the formation are often responsible for this permeability loss. Permeability and leaching tests were done in the laboratory on clayey ores to evaluate a clay-stabilizing polymer's effectiveness in preventing these problems. Test results indicate that treating the ores with the stabilizer could maintain permeabilities two to five times greater than the long-term permeabilities present in untreated ores. Both alkaline (pH 8.5) and acidic (pH 2.0) leaches were used in the permeability-leaching tests. Since in situ leaching throughput rate is directly related to permeability, these results also indicate a potentially beneficial effect on operating parameters such as capacity and injection pressure. To determine the reasons for the success of the clay stabilizers, an investigation was conducted to cieter-mine the effect of the stabilizer on clay swelling and dispersion. Clay-swelling tests indicated that the clay stabilizer reduced clay swelling. Zeta potential measurements made on fine clay particles treated with the stabilizer were compared to measurements made on untreated particles and indicated that the stabilizer was electropositive and, therefore, could reduce the degree of negative charge on the particles and their tendency to disperse or migrate.

Jan 1, 1984

By Oliver Bowles

The National Granite Commission at its annual meeting in Norfolk, Va., in January, 1930, passed a resolution requesting the Bureau of Mines to conduct an economic study of the granite industry. In compliance with this request a preliminary review has been made of trends, in, the production and uses of block granite. Some unfavorable conditions, were, thus brought to light and certain suggestions regarding a. more orderly and consistent growth in the industry are herein discussed. The results of the study axe, presented in this report for the earnest consideration of the industry and comments are invited, not only on this report but as to future work that might be accomplished by the Bureau of Mines. The authors desire to acknowledge many helpful suggestions and comments from Paul M. Tyler of the Bureau of twines and from Harris F. Sherman, secretary of the National Building Granite Quarries Association. Miss A. T. Coons of the Bureau of Mines rendered valuable, assistance through her wide knowledge of granite statistics.

Jan 1, 1931

By D. Harrington

[Notwithstanding the fact that it is now fairly generally recognized that widespread explosions can be almost absolutely prevented in coal mines by efficient rock-dusting and that this rock-dusting can be done thoroughly at a cost which should seldom exceed 1 cent per ton of coal mined, a recent survey of the situation by the Safety Division of the U. S. Bureau of Mines, following a similar survey by the Bureau in the fall of 1925, shows that while some progress is being made by our coal-mining people, many entire mining communities are lamentably slow in taking advantage of one of the most effective safeguards available. Much of the information as to the extent of rock-dusting was obtained through the various State inspection departments. Table 1 shows that in the fall of 1925 about 92 coal companies in the United States were using rock-dust ad that in the summer of 1927 the number had increased to 239, or about 160 per cent increase. Similarly, from the fall of 1925 to the summer of 1927 the number of mines using rock-dust increased from 177 to 463, or about 160 per cent increase. This appears to be a decidedly healthy increase, but when it is considered that in 1926 (the last date for which figures are available) there were 7,141 bituminous mines operating and that there were only 463 or 61 par cent, which were even reported to Ice using rock-dust to any extent whatever, the forgoing figures as to progress are by no means impressive or even satisfactory.]

Jan 1, 1928

By T. A. Evans

The Bureau of Mines conducted a Laboratory and pilot-plant investigation of the flotation of iron sulfides from zinc-lead mill tailings near Platteville, in south-western Wisconsin, at the North Central Experiment Station, Minneapolis, Minn. The procedures used and the results obtained in this investigation are described in this report. Samples for laboratory tests were obtained from each mill in the district, namely, Calumet & Hecla, Inc., Eagle-Picher Co., Vinegar Hill Zinc Co., and Tri-State Zinc, Inc. The sample fat pilot-plant work was obtained from the Davis Mining Enterprises mill.

Jan 1, 1957

By R. D. Leitch

Spontaneous firing of coal during storage end even during shipment has long been a serious problem, especially in some regions and with some coals, and methods for preventing such firing have been investigated at intervals for more than 70 years. Spontaneous or other firing of coal waste, either outside or inside mines, has also been a problem probably for as long as mining has been practiced extensively. Much trouble has been caused by such fires, and much money has been spent in attempts to extinguish them. It is known generally that surface waste banks in bituminous-coal fields are very likely to take fire sooner or later, but it is not known so generally that anthracite refuse-bark fires also are common and that at least some of them are more serious in their effect and results than being regarded merely as a nuisance. There surface refuse fires probably would have attracted much more than local attention long ago had it not been that they usually cause no more serious trouble than air pollution. A few supposedly effective methods of preventing or extinguishing spontaneous fires have been reported rather recently. Unless one or more of these prove to be widely applicable, methods of solving these problems are no more certain today than they have been for many years.

Jan 1, 1940

By STUART R. BRINKLEY, Ruth F. Brinkley

This same phonomonon of diffraction may be transposed into the X-ray domain. All that is necessary is to reduco, in the samo proportion, the wavo length of the light and the diameter of the particlo; thus, with radi- ations whose wave length is of the ordog of angstroms, the dimensions of the active particles go from 10 to 100 A that 18, the dimensions of col- loidal particlos. The evidence of this fact is shown by the following experimental schomo (fig. 1a): A narrow beam of X-rays passes through a thin layer of a modium containing micelles; the photographic film is placed a few centimeters behind the sample, and a small absorbing screen stops the direct beam in order to prevent its fogging the film. The intersect of the direct beam is surrounded by a narrow spot whose blackness decreases with the distance from the center. We will call this the spot of central diffusion (fig. 1b). The phenomenon, in spite of its relatively reat intensity, has been observed only by a few authors, who have simply given a qualitative description without attempting any quantitative de- ductions. This is due to the fact that observation of this phenonenon is not possible with the apparatus generally used to obtain X-ray diagrams, because the parasite foggings in the vicinity of the incident beam are sufficiently important to hide those produced by the sample. With the monochromator, however, used by us to obtain Debye-Sherer diagrams, this parasitic diffusion can be totally suppressed. In this way our attention was again directed to the spot of central diffraction, and we were led to make a detailed quaititative study of it.. then several papers have been published on this subject. Hosemann, using methods of calculation outlined by us, has extended them to the special case of fibrous substances, Kratky, on the other hand, starts from an entirely different theoretical point of view; ho examines the case, not of scattered particles, but of closely packed particles. 6ince We will now describe the experimental methods, summarize the calcu- lations needed in the elaboration of diagrams, and finally review the first results obtained in the vast domain of these new physical-chomical studies.

Dec 1, 1946

By O. S. North

As recently as the late 1920's there Were few indications that a 15-million-dollar-a-year industry would ever grow out of the mineralogic curiosity vermiculite. Today, it is an important industrial commodity, used primarily as an insulating material and lightweight aggregate, but with a wide range of other applications. The quantity of crude vermiculite produced and used in the United States increased 14-fold in the 17 years between 1935 and 1951. The vermiculite minerals are of secondary origin, formed by hydrothermal alteration of an ultrabasic igneous rock, generally pyroxenite, or by alteration of phlogopite or biotite mica or possibly other similar minerals. According to different authorities, vermiculite may originate either by direct hydrothermel means, by the weathering of biotite or phlogopite, or by a combination of these two agencies. Vermiculites frequently occur at or near the contacts of an acid intrusive rock, especially a pegmatite dike, with a basic or ultrabasic country rock.

Jan 1, 1953

By J. W. Paul

This circular is one of a series of papers4 on coal-mining methods and costs which are being prepared through the sponsorship of the U. S. Bureau of Mines for the purpose of presenting information on present mining methods and certain features which govern costs, safety, and conservation. The methods employed are influenced by natural local conditions with respect to the thickness, character, and dip of the coal bed, the nature of the roof and thickness of the overbearing strata, and the means employed for roof support and its control.

Jan 1, 1929

By F. E. Griffith

[Unquestionably mine fires new constitute one of the chief causes of sabotaging the effort to produce maximum quantities of mineral products essential to the prosecution of the war. This applies more particularly to coal than to noncoal mines, and presumably the main reason for this is the fact that coal production in maximum quantity is still very much a "must", while the demand for much of the product of noncoal mines has eased materially in recent months.]

Jan 1, 1944

By E. C. Foster

The project objective of this contract is to design, develop, and demonstrate a dust collecting system for auger head miners, used in coal seams 40 inches or less in height, which will reduce respirable dust below the limits established by the Federal Coal Mine Health and Safety Act of 1969. This system was to be incorporated into 3 Wilcox Mark 20 continuous miner. In order to accomplish this, the objective was divided in three main areas. First: To develop a dust control system which would remove by isolation, respirable dust from the face area and areas where miners work. Second: To develop a dust scrubbing system to remove and collect float dust before the air reaches the return airway. Third: To reduce the overall noise levels to which the miners are exposed.

Jan 1, 1974