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Unfortunate occurrences resulting in injuries, loss of life, and destruction of property by explosion, fire, and other mishaps during shaft sinking focused the attention of the Bureau of Mines on the need for safety standards For such operations. Information Circular 7810 was published to meet that need. The current revision updates and replaces IC 7810. Several States have some rules and regulations applicable to local conditions, and several Bureau publications (including some now out of print) cover the hazards that may be encountered in shaft sinking. Certain requirements of the Federal Mine Safety Code and Federal Coal Mine Safety Act may be applied, but there are no definite, uniform standards that will guide those desiring to sink a shaft safely and bring about uniform safety inspections.

Jan 1, 1968

By E. O. Binyon

"Corundum and andalusite were discovered in August 1944 on what is now known as the Blue Metal group of claims. The property, comprising five unpatented lode claims, is situated 20 Miles northwest of Yerington in the Buckskin Mining District, Douglas County, Nevada, An engineer of the. Bureau of nines examined the property on November 1, 1944, and recommended a small: amount of drifting and crosscutting to determine more definitely the extent and character of the ore deposit. The work that had been done by the owners was for sampling purposes only and was confined to a few small pits on the outcrop, and no effort had been made. to delimit the ore zone. Samples taken from the best surface showings were sent to the experimental station in Salt Lake City for beneficiation tests. The results of the preliminary test work appeared favorable, and upon the strength of them and the recommendations made by the Bureau, 2.5 miles of access road was approved and completed early in 1945. Exploration was started on June 24 and completed September 26, 1945.In its program of exploration of mineral deposits, the Bureau of Mines has as its primary objective the more effective utilization of our mines resources to the end that they make the greatest possible contribution to national security and economy. It is the policy of the Bureau to publish the facts developed by each exploratory project as soon as practicable after its conclusion. The Mining Branch, Lowell B. Moon, chief, conducts preliminary examinations, performs the actual exploratory work, and prepares the final report. The Metallurgical Branch, R. G. Knickerbocker, chief, analyzes samples and performs beneficiation tests. Both these branches are under the supervision of Dr. R. S. Dean, assistant director.This paper is one of many reporting on various aspects of the Bureau of Mines program initiated in August 1939 by passage of the Strategic Minerals act, the scope of which was. greatly expanded by subsequent legislation.Some of these papers were published as war minerals reports, others as bulletins, technical papers, reports of investigations, and information circulars of the Bureau of Mines or• in, technical journals.The Bureau's program at first included separate investigations by the Mining and metallurgical Divisions, but these were consolidated under Assistant Director R. S. Dean beginning July 1, 1942. Mining and metallurgical investigations carried on in three regional organizations more closely integrated thereafter by a staff of specialists, who reviewed findings made in the field and in Bureau Laboratories, considered proposals for additional work, revised reports for publication, and served as advisors to the assistant director."

Aug 1, 1946

By Donald W. Ross

Petroleum oils of widely different grades have long been clarified or decolorized by contact with fuller's earths. More recently, so-called activated clays have also been used for this purpose. Still more recently ouch clays have been used in the form of nodules termed "catalytic pellets." Clays of varied appearance and from different localities possess the desired bleaching qualities, but evaluation of such clays, so useful to the oil industry, has not been simple. Previous methods of identification and evaluation have largely followed procedures of production methods and were not primarily based upon the fundamental properties of the clays. Thus) a false assumption has grown up that) bleaching clays probably have no common properties on which a-method of comparison can be based. Fuller's earths and activated clays have a large absorptive capacity for the color constituents of petroleum and its products decolorizing is accomplished by bringing the oil into intimate contact with the clay and later separating the decolorized oil from the clay with its load of absorbed coloring matter. Former practice in absorbing "color" was to use the clay as granules or In' powdered form. More recent practice is to use clay pellets that are more abrasion-resistant than the granules. The oil is either filtered through a bed of clay, percolation method, or agitated on contact with the clay, contact method. Viscous oils are decolorized at an elevated temperature, so that their viscosity is lowered to the point at which thorough contact with the clay is insured. Nonhumidifying, nonoxidizing gas, such as dry steam or dry nitrogen, is used to seal such hot oil masses from the atmosphere.

Jan 1, 1948

By Walter W. Fowkes

Leonardite is a coallike substance, similar in structure and composition to lignitic coal and believed to be derived from lignitic coal by the process of natural oxidation. Leonardite is little known outside lignite-producing areas and has been developed commercially only to a minor extent. The higher oxygen content and less compact structure of leonardite, compared with lignite, make it undesirable as a fuel but indicate that it has potential as a source of chemicals and for other nonfuel uses. It is a convenient source of humic acids. The United States has a large natural reserve of leonardite; furthermore, it can be produced in the laboratory under controlled conditions. The significant elemental difference between leonardite and lignite is the oxygen content (leonardite, 28-29 percent; lignite, 19-20 percent). The higher oxygen content of leonardite is due entirely to a Larger number of carboxylic acid groups. This fact explains the 17-Cold increase in alkali solubility of leonardite. Spectral studies indicate that the material is mixed salts of humic acids.

Jan 1, 1960

By J. W. Adams

Measurements of surface magnetic field noise were made at various locations over the Geneva Coal Mine near Price, Utah, on June 12, 1973. The locations selected were on the surface over emergency locator beacons underground at depths between 3S0 meters (1150 ft.) and 488 meters (1600 ft.). The surface terrain where these measurements were made was mountainous, and access was difficult. There were no power lines within several miles, and the weather was clear; therefore, the magnetic noise levels were about as low as will normally occur. Results of measurements of distant sferics indicate rather sharp cutoff frequencies below which broadband, impulsive noise is attenuated. The mechanism of propagation for this noise above the daytime cutoff frequency of 3500 Hz and the nighttime cutoff frequency of 1700 Hz is deduced to be a waveguide formed by the D or F layers of ionosphere as an upper plane and the earth as a lower plane.

Jan 1, 1974

By P. L. Woolf

Two blast furnaces, one a. commercial furnace and the other the Bureau of Mines experimental furnace, were successfully operated with extremely low slag volumes. The lowest slag rate obtained on the industrial furnace was 335 pounds per ton of metal. Using the same burden materials a 245-pound slag volume was achieved on the furnace. The coke rate saving and increase in productivity resulting from lowered slag rates are discussed as well as the factors limiting a low slag practice.

Jan 1, 1965

By Raymond B. Ladoo

Garnets are usually found well crystallized in the cubic system , the principal forms being rhombic dodecahedrons , tetragonal trisoctahedrons or combinations of the two , and hexoctahedrons . They also occur as rounded disseminated glassy grains and in compact massive , laminated or gramlar aggregates . They vary greatly in color , but the most common garnets , almandite and andradite , are most often found of a dark red or reddish brown color .

Apr 1, 1922

Approximately half of all the fuel energy used in the United states is now pro-vided by oil and natural gas. A persistent and rapid growth in energy demand during the last 3 decades has been absorbed largely by the liquid and gaseous rather than solid fuels. In 1948 the energy provided by coal was substantially the same as in 1920. Meanwhile, the use of oil and natural gas each had increased fivefold. On a per capita basis, the change is more significant. Coal consumption has dropped from about 6 tons per person to 4-1/2 tons, while oil has increased from 4-1/3 barrels to 14-1/3, and natural gas from 7,500 cubic feet to about 35,000. These facts would have only academic interest if the United States had unlimited supplies of all fuels. However, while the Nation's reserves of coal are adequate to meet our needs for centuries, those of oil and natural gas appear limited. It is obvious, therefore, that the security of our liquid-fuel position would be greatly enhanced if the supply could be based in an increasing degree on solid fuels, such as coal and oil shale, which make up more than 95 percent of our fuel reserves, instead of natural oil and gas. In addition, this would create new employment and help to stabilize the market for coal, which may be facing comparatively bleak prospects in the near future unless its position with respect to other fuels is improved.

Jan 1, 1950

By Kenneth J. Miner

Pittsburgh bed and Lower Freeport bed coals were tested in the U.S. Bureau of Mines two-stage froth flotation pilot plant, which utilizes a new flotation process to remove pyritic sulfur. The process consists of a first-stage coal flotation step to remove coarse, free pyrite and other refuse in the tailings. The clean coal froth concentrate is then repulped and treated with a coal depressant, a pyrite collector, and a frother to selectively float the remaining pyrite in a second stage. Results in the pilot plant were excellent, comparing well with those obtained in laboratory batch tests. That is, about 70 percent of the pyrite present in the Pittsburgh bed coal and about 90 percent of the pyrite present in the Lower Freeport bed coal were removed with excellent final clean coal recoveries.

Jan 1, 1973

By Frank L. Hess

In 1876 cassiterite was identified in the placer gold from the northern Black Hills, and such a mixture could have come only from Nigger Hill or one of the streams draining the hill, because in no other hart of the northern hills have cassiterite anti gold been found together. Nigger Hill is in western Lawrence County, South Dakota, and on it is the little camp of Tinton. The Wyoming line runs along the west side of the hill and crosses the ridge which is the hill's continuation about miles north-northwest of Tinton.

Jan 1, 1938

By Richard F. Hewlett

This Bureau of Mines report presents the computer programing methods and mathematics required to generate either random numbers or normal random numbers to be used for the construction of statistical probability models for simulating mineral deposits by Monte Carlo techniques . Theoretical frequency functions are evaluated as an illustration of simulation applications . Numerical and analytical methods of simulating and dissecting some complex frequency distributions are described .

Jan 1, 1964

By Kim B. Shedd

The Bureau of Mines measured fiber dimensions on crocidolites (riebeckite-asbestos and magnesioriebeckite-asbestos) from the world's four crocidolite mining regions. The objective of the study was to determine whether there are measurable morphological differences between crocidolite fibers that correlate with the high reported incidence of mesothelioma in miners and mill employees in the Cape Province of South Africa and Western Australia, as compared with little or no reported incidence of this cancer in the Transvaal Province of South Africa or Bolivia. Fiber dimensions measured with the scanning transmission elec-tron microscope showed that crocidolites from Western Australia and the Cape Province have more thin fibers than crocidolites from Bolivia and the Transvaal Province.

Jan 1, 1985

By J. W. Griflith, P. A. Mack, C. M. Lang, S. Riling

"N-acetyl-beta(B)-D-glucosaminidase is a N-acetyl-beta((B)-D-glucosaminidase enzyme se¬creted by alveolar macrophages in response to phagocytosis of particulate material. Alveolar macrophages participate in the degradation and fibrosis of pulmonary tissue that results in pneumoconiosis. Known quantities of four characterized respirable dusts were bronchoscopically placed into the right caudal lung lobe of macaque monkeys. Bronchoalveolar lavage (BAL) samples were collected from dust-exposed right lung and unexposed left lung of the same individuals at 2-week intervals for 12 weeks after dust instillation. The samples were tested for N-acetyl-B-D-glucosaminidase activity to determine if the enzyme levels could serve as an indicator of pulmonary injury induced by generic coal dusts when compared to known fibrogenic and nuisance dusts. Installation of generic quartz, anthracite, or TiO2 dusts produced significant elevations of enzyme activity and increased numbers of macrophages in the dust-exposed lobes. Elevations in enzymatic activity and macrophage numbers were greatest in response to generic quartz dust. These results suggest that quantitative levels of N-acetyl-B-D-glucosaminidase activity may be a useful indicator of acute and chronic lung injury following exposure to fibrogenic and nonfibrogenic dusts.IntroductionCoal workers pneumoconiosis (CWP) is an occupational pulmonary disease associated with the inhalation of coal mine dust. An important external factor in the development of CWP is the composition of the respirable coal mine dust. A cause-and-effect relationship exists between coal mine dust and CWP, but it has not been shown that exposure to generic coal dusts will cause CWP [12]. Numerous immunological, biochemical, and cellular changes occur in CWP; however, in this study, only N-acetyl-beta(B)-D-glucosaminidase (NAGase), protein, and alveolar macrophages (AM) will be examined [7, 32, 33]."

Dec 1, 1996

This project, "Analysis of Men, Materials and Supplies Handling Systems in Underground Metal and Nonmetal Mines" documents the productivity and safety aspects of the existing equipment and systems utilized in transporting personnel and supplies from the surface to the underground production work place. The Present Systems Study (this text -Volume II) documents the productivity and safety of existing men and material movement systems for six representative underground metal and nonmetal mines. Identification of common problem areas was performed using recognized industrial engineering techniques. The back-up data for the industrial engineering analysis of each mine is included as respective appendices (Volume III). A summary of the study background material, six mines' problem areas, comparison of problem areas, problem analysis, and solution recommendations are included as the project final report (Volume I), bound under separate cover.

Jan 1, 1975

By Bertrand L. Johnson

As potash is more necessary to the agricultural economy of the United States now than ever before it is gratifying to find that the virtual stoppage of imports from Germany in late 1939 caused none of the anxious foreboding that gripped American farmers in 1914. For long decades this country, in common with tie rest of the world, depended upon German potash, but today our expanded needs can be mot from domestic sources. The present armed conflict in Europe, like that of 1914, disrupted a world monopoly, but the cartel that in recent years controlled 90 percent of the world output (see fig, 1) was an international syndicate comprising French, Polish, and Spanish as well as German producers and having reported sales agreements covering production in the U. S. S. R. and Palestine. The break-up of these commercial agreements has necessitated readjustments but generates no such alarm as the closing of a single source of supply. In striking contrast to the critical shortage that developed a quarter century ago, no increase in prices has occurred or is anticipated in the domestic market.

Jan 1, 1940

By William H. Pomroy, Annie M. Carigiet

This U.S. Bureau of Mines publication is an analysis of underground coal mine fire incidents occurring in the United States during the 15years from 1978 through 1992. The fire data used in this analysis were obtained from U.S. Mine Safety and Health Administration mine fire investigation reports. Fires were analyzed by year, State, coalbed thickness, mine size, mining method, ignition source, burning substance, location, equipment involved, detection method, time of day, time of year, number of injuries and fatalities, method of extinguishment, and evacuation measures taken. In all, 164 fires are included in this report, or an average of 10.8 fires per year. The most fires occurred in West Virginia, Kentucky, and Pennsylvania, respectively. However, the fire incidence rates for these States, expressed as the number of fires per million tons of coal mined, were the lowest, second lowest, and fourth lowest of all underground coal producing States. The most common ignition source was electricity; the most common burning substance was coal; the most frequent fire location was the belt entry; the most common equipment involved in fires was the conveyor belt; and the most common extinguishing agent was water.

Jan 1, 1995

By Frank L. Hess

In 1876 cassiterite was identified in the placer gold from the northern Black Hills, and such a mixture could have come only from Nigger Hill or one of the streams draining the hill, because in no other part of the northern hills have cassiterite and gold been found together. Nigger Hill is in western Lawrence County, South Dakota, and on it is the little camp of Tinton. The Wyoming line runs along the west side of the hill and crosses the ridge which is the hill's continuation about miles north-northwest of Tinton.

Jan 1, 1938

By M. Kanda, W. D. Bensema, J. W. Adams

Two different techniques were used to make measurements of the absolute value of electromagnetic noise in an operating hardrock mine, Grace Mine, located near Morgantown, Pennsylvania. Diesel-powered haulage equipment is used in this mine, and the electromagnetic noise environment it creates was measured to see how it differs from the environment created by electric-powered haulage equipment. One technique measures noise over the entire electromagnetic spectrum of interest for brief time periods. Data are recorded using broadband analog magnetic tape and are later transformed to give spectral plots. The other technique records noise amplitudes at several discrete frequencies for a sufficient amount of time to provide amplitude probability distributions. The specific measured results are given in a number of spectral plots and in amplitude probability distribution plots.

Jan 6, 1974

By M. R. Geer

The widespread adoption during the past decade of the dense-medium process for cleaning coal increases the need for technologic studies of the process. Such studies provide information that will insure maximum usefulness of this process in its present form and may well lead to substantial improvements in design and opera¬tion. The Bureau of Mines has published the results of cleaning trials on a wide variety of coals in two dense-medium pilot plants5/ and reported the recovery of coal from waste by dense-medium treatment.6./ The present report deals with the viscosity of magnetite dense medium, an important subject about which virtually nothing has been published. Specifically, the report concerns methods for measuring viscosity, the influence of various medium contaminants on viscosity, the effect of viscosity on cleaning results, and the influence of viscosity on consumption of medium. Cleaning trials on four coals of varied density composition in a pilot plant, using mediums of different viscosities, showed a steady reduction in cleaning efficiency with increasing viscosity in every instance. However, the behavior of each coal in a viscous medium was distinctly individual. With one, an increase of only 1 centipoise in viscosity caused a reduction in recovery efficiency of 7.7 percent, whereas the same increase in viscosity with another reduced recovery efficiency only 2.7 percent.

Jan 1, 1957

By L. W. Scott

This report presents an overview of explosionproof (X-P) enclosure research being conducted by the Bureau of Mines, This report emphasizes the increasing importance of research related to the safety con- siderations of X-P enclosures used in underground coal mines. Selected topics are included that summarize results of research in the areas of electrical clearances, reliability of enclosures with windows, safety factors in X-P enclosures, potting materials, performance tests for X-P enclosures, protection against high-voltage explosions, and innovative X-P devices.

Jan 1, 1985