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By H. L. Gibbs

A portable radon monitoring instrument capable of making on-the-spot measurements of the radon gas content of uranium mine atmospheres was designed and constructed. The monitor was tested in the laboratory and in operating uranium mines. Good correlation was obtained between the monitor readings and radon measurements made on mine atmosphere samples taken in radon bottles.

Jan 1, 1973

By A. F. Colombo

The differences in starch demands that occur between ore types subjected to the anionic flotation of calcium-activated gangue and the range of residual starch contents expected to give the best metallurgical response were evaluated on a batch and pilot plant basis. A phenol-sulfuric acid procedure was used to determine the residual starch contents in the iron ore slurries. Three pilot plant campaigns on samples from a group of orebodies located on the Marquette Range, Michigan, showed that in the rougher flotation pulp, a residual carbohydrate range of 25 to 100 ppm, which is equivalent to a 0.5 lb/short ton spread, yielded optimum results. Concentrates assaying at least 65 percent Fe and less than 6.0 percent Si02 and containing more than 80 per-cent of the recoverable iron were obtained. Both batch and continuous research indicated that starch adsorption is calcium modulated and relatively unaffected by the fatty acid additions employed. Residual starch level is not a critical control factor, but the addition must be adjusted to about 25 to 50 ppm residual starch and kept in this range for most effective utilization of the added tapioca flour.

Jan 1, 1972

By Robert H. Schutz

This publication lists and describes devices approved jointly by the Secretary of Interior and the Secretary of Health, Education, and Welfare, under the provisions of [§]70.300-1, Part 70, Subchapter 0 of Chapter I, Title 30, Code of Federal Regulations (35 F.R. 5548, April 3, 1970), for use as respiratory protection against respirable pneumoconiosis-producing dusts. Included are type C supplied-air respirators approved under Bureau of Mines Schedule 19R and dust, fume, and mist respirators approved under Bureau of Mines Schedule 21B.

Jan 1, 1971

By G. M. Martinez

A cell concept adaptable to large-scale electrowinning of zirconium metal from zirconium tetrachloride was investigated by the Federal Bureau of Mines. Tests were made in twin cells, each 12 inches in diameter by 33 inches long. Electrowinning was performed in one chamber from which the electrolyte was transferred after electrolysis to the other chamber where it was renewed by the introduction of ZrC14 by direct sublimation. The formation of a salt plug in the connecting pipe provided a seal between the chambers. Optimum electrolyte composition, with respect to quality of the metal product (91 pct meeting ASTM standards except for the oxygen content) and current-carrying capability (about 350 amp) was determined to be 16.7 wt-pct NaF-83.3 wt-pct NaCl mixture plus ZrC14 equal to about 3 wt-pct zirconium. A twin-cell design incorporating the unit operations covered by this investigation is proposed.

Jan 1, 1976

This report summarizes the work performed by the Bureau of Mines on the development of analytical procedures for determining metallic and interstitial impurities in high-purity tungsten. Fourteen published methods and seven unpublished methods are briefly described. Carbon, hydrogen, nitrogen, and oxygen, in microgram to higher quantity levels, can be determined by several methods. Trace levels of 29 metallic impurity elements can be determined by optical spectrography, X-ray spectrography, and other instrumental methods.

Jan 1, 1968

By A. E. Wells

"When the United States entered the World War, the heavy requirements for sulphuric acid in the manufacture of explosives made necessary a definite knowledge of the sulphuric acid capacity of the country. The Bureau of Mines, under the authority conferred by the explosives regulation act, made a thorough survey of the sulphuric acid situation. In this work, which was personally directed by the writer, comprehensive data were collected on the situation and capacities of the various acid plants, sources of supply of raw materials (brimstone, pyrite, pyrrohotite, zinc ores and concentrates, waste sulphur dioxide gases from copper smelting, and spent oxide from gas works), the principal points in regard to manufacturing processes (chamber and contact) and the uses of the acid. The results of this investigaion have recently been published by the Bureau of Mines, as Bulletin 184, entitled ""The Manufacture of Sulphuric Acid in the United States"" by A. E. Wells and D. E. Fogg. The following paragraphs on the uses of sulphuric acid are abstracted from this bulletin.Sulphuric acid is one of the most important of all chemicals, not only because of the large quantities manufactured but also because of the wide use of the acid in many different industrial works. Sulphuric acid is to the chemical industry what iron is to metallurgy. The general public, however, does not realize this fact, for sulphuric acid does not appear in the finished product as does iron and steel, but is only a means to an end. It is essential in many industries, such for example as in the manufacture of phosphate fertilizers, explosives, dyes and petroleum products. In recent years in the United States, especially in the East, the demand for sulphuric acid for chemical and metallurgical industries has been an accurate and sensitive barometer of the general business conditions. This demand for acid responds much more quickly to a general slump or boom in the industrial world than does the demand for iron and steel."

Oct 1, 1920

By G. Dale Cor, Will H. Coghill, M. F. Williams, I. L. Feld

"INTRODUCTION During the past several years the Southern Experiment Station of the Bureau of Mines, with the cooperation of the University of Alabama, has given attention to hydraulic classification. One of the things this work has revealed is a variability not generally recognized in the conditions of teeter at different depths. This report depicts the passage of material through a teeter column and its emergence as a classified product.The work was made possible through the development of a classifier for several hundred pounds per hour permitting a small quantity of coarse spigot material to be discharged without the usual interruptions caused by stop-pages. Previous designs of small classifiers have been unsatisfactory because the,orifice used to control the quantity of spigot product as subjectto stoppages, particularly when attempting to discharge a small quantity of although the classifier used in this work has been described in detail in a previous publication 6/ its principal features will be discussed briefly herein. The main subject matter of the paper is based upon the three figures that illustrate in panorama the conditions that exist in a classifier during the continuous classification of bituminous coal, anthracite coal, and an iron ore trailing."

Jan 1, 1946

By R. V. Ramani, R. Bhaskar

"One of the primary means of control of health hazards from respirable contaminants in mine atmospheres is through design and operation of mines to meet mine health and safety regulations and recommended practices. A U.S. National Academy of Sciences study concluded that for significant progress in coal mine dust control, research should be directed more toward obtaining fundamental understanding of the origin, transport and characteristics of respirable coal mine dust. Theoretical and experimental studies on transport of dust · in mine airways, particularly coordinated efforts to validate theory with practice, are scarce. Some empirical models, developed on the basis of experimental data, are available but these models cannot be applied to new conditions. The purpose of this paper is to present the results of theoretical and experimental studies on the transport and deposition of dust in mine airways. This study is a part of an ongoing research project in the Generic Mineral Technology Center on Respirable Dust.In the paper, the assumptions of the modeling phase of the project and the development of a convectiondiffusion equation for dust transport in mine airways are outlined. The important aspect of the modeling effort is the capture of the deposition phenomenon. The experiments performed under controlled conditions in a typical mine airway, as well as under normal mine operating conditions, are discussed. The comparison of the model predictions with experimental results are made to identify critical areas of agreements and deviations. The implications of the findings and areas for further research and development are presented."

Jan 1, 1990

By N. S. Dalal, N. Leelarasamee, V. Castranova, K. Van Dyke, V. Vallyathan

"INTRODCICTIONSilicosis is the chronic fibrosing disease of the lungs caused by the inhalation of crystalline silica. However, inhalation of crystalline silica, may induce three distinctly different disease patterns; i.e., chrome silicosis, accelerated silicosis, and acute silicosis. These three disease patterns differ in their pathologic characteristics, clinical symptoms, onset of disease, and mortality. Many studies in the past have focused on the elucidation of mechanisms involved in the development of chrome silicosis. We recently reported that freshly fractured silica has surface properties that could make it more reactive with lung tissue than aged silica, and that this unique reactivity of freshly fractured silica may be involved in the pathogenesis of acute silicosis (Dalal et al., 1986; Vallyathan et al., 1988; Shi et II., 1988). Because freshly fractured silica could contain some moieties in an ""excited state,"" due to the breakage of silicon oxygen bonds, we postulated that the de-excitation of these moieties could produce light which could be monitored by a luminescence measurement technique. In addition, if this ""excited state'' of silica could trigger a greater biologic response by phagocytic cells, this activation could be monitored by a chemiluminescence technique in the presence of appropriate enhancers.This investigation describes for the first time the use of luminescence in the study of freshly fractured silica and its properties. Enhanced biologic reactivity of the freshly fractured silica with alveolar macrophages was monitored by the chemiluminescence technique.MATERIALS AND METHODSNative silica was obtained from the dust bank of the GenericRespirable Dust Technology Center, Pennsylvania State University, State College, PA, and ground for 3~ min in an agate ball mill. It was then sieved through a 20 micron mesh filter and used within 1 O min as fresh silica or stored in glass bottles for aging. X-ray energy spectrometry and X-ray powder diffraction studies on representative samples were made to confirm the mineralogic purity. All the silica samples were found to be 99 % pure with minimal detectable conlamination by metal ions."

Jan 1, 1990

By T. D. Ralston

This Bureau of Mines report presents a mathematical model for heterogeneously catalyzed chemical reactors operating under turbulent conditions. The model includes reaction kinetics on the catalyst surface as well as diffusion of the reacting components within the reactor. Three applications of the model to tube-wall methanation reactors are discussed. The first application is a computation of catalyst activity from measured reactor data. This result is then used in a reactor sizing problem and a problem of reactor simulation with recycle. In addition to the reactor model, a novel approach to solving the recycled reactor problem is given.

Jan 1, 1974

By J. R. Bartels

Operation of underground coal mine mobile equipment is usually done in a restricted workspace with reduced visibility. This work environment puts machine operators in awkward postures for tasks that require awareness of their surroundings and fast reactions to avoid hazardous situations. Using experienced equipment operators as a source, researchers conducted an investigation that developed a method to gather data on the needs and practices of machine operators while controlling the machine and the reasons for needing particular operational cues. The method used was an interview technique including a survey questionnaire and visual aids. The data gathered defined operator cues and work positions for the cutting and tramming phases of remote controlled continuous mining machines used in underground coal mines. Analysis techniques to determine which cues an operator sees from a variety of positions utilizing a computer simulation is shown to be potentially useful to the mining industry for design of work practices and workplace layout and could impact equipment design and selection for improved worker safety. Conclusions indicate that the survey was a good research tool to collect data and helped investigators understand important visual cues. Using this information, researchers were able to analyze the visual cues an operator can see from a given work position and posture.

Jan 1, 2009

By T. N. McVay

The Bureau of Mines has developed a field test for detecting the presence of columbium in a variety of minerals containing the clement. The test consists of fusing the mineral or rock powder with potassium pyrosulfate in a porcelain crucible, digesting the melt with hot dilute hydrochloric acid to release the columbium oxide (Cb205), and subsequently reducing the columbium oxide to a lower oxide by adding tin, which gives a blue color to the contents of the crucible. The method will detect 1 percent of contained columbium oxide (Cb205) in a mineral sample provided no tungsten is present. If a mineral containing appreciable titanium is test,-!d in the same manner, the solution in the crucible becomes violet. In the presence of columbium, titanium at first causes a violet coloration of the solution, which after a few minutes is masked by the stronger blue of the reduced columbium oxide. Although tantalum oxide (Ta205) does not interfere with the columbium test, tungsten gives a blue color that is indistinguishable from the color obtained with columbium. A simple method is available to detect the presence of columbium in the absence of tungsten, but when the presence of tungsten is suspected, the sample must be subjected to somewhat more elaborate chemical tests to determine the presence or absence of columbium. Although these latter tests can be made in the field, several steps are involved that arc best performed in the laboratory with simple equipment.

Jan 1, 1962

By Robert L. Thorne

As an integral part of the investigation of critical and essential minerals in Alaska , the Bureau of Mines examined the lead deposits in the Slana area . Four examinations were made during June , July, and August 1945 in the 200 - square -mile area immediately northwest of Slana . The settlement of Slana lies near the conflux of the small Slana River with the mighty Copper River less than 60 miles southwest of Tek Junction on the Alaska Highway . Travel through the area and the examination of the properties were conducted by a three-man crew consisting of the author , a caterpillar operator , and a laborer . An RD6 caterpillar , equipped with blade and winch , was used in breaking trail and freighting through the country . Supplies and equipment were loaded on a 7- by 14 -foot , double - end , go -devil , which was hauled by the tractor .

Nov 1, 1946

By G. L. Neumann

In October 1949 the College Park Branch of the Mining Division instituted a survey of the New England pegmatites. Many of the New England pegmatite deposits were superficially examined, and the Bumpus quarry in Albany, Oxford County, Maine (see fig. 1), was selected for a diamond-drill exploratory-development project to supply information for developing more economical mining methods and no increasing production of beryl and other scarce minerals associated with pegmatitic intrusives. The Bumpus quarry has been mined intermittently by three operators since it was opened in 1927. At the time of drilling, the vein or dike (see figs. 2 and 3) had been mined to a depth of 60 feet for a strike length of 280 feet. The dike averages 40 feet in thickness and dips 50 degrees southeast. The Bureau of Mines drilled seven diamond-drill holes between September 27 and November 27, 1950. These holes showed that the dike persists for at least 350 feet to the east and probably 200 foot to the west of the present excavation. The drilling also indicated that the dip, as exposed at the surface, continued unchanged at 500 to a depth of at least 50 foot below the pit. The dike was not delineated, although it fingered out as pegmatite interbanded with Granite, diorite, and gneiss in diamond-drill hole B-4, approximately 250 feet west of the pit. Further drilling will be necessary to find the extent of this pegmatite dike and to determine the safest and most economic mining system.

Jan 1, 1952

By J. W. Faul

[The Bureau of Mines initiated an extensive research on coal-mine ventilation factors in 1922, large- scale tests being conducted in its experimental nine near Bruceton, Pa., over a period of two years. A comprehensive report an this work is in course of preparation, but in order to place the practical results before the mining fraternity immediately and in condenses form, the more important features will be presented in a number of short papers. The present report is the first of a series dealing with the resistance of coal-mine entries to the flow of air and considers only entries in which there are no obstructions other than the natural roughness of the ribs, roof, and floor.]

Jan 1, 1924

By George S. Rice

There have appeared, from time to time, comparisons of various features of coal mining practice in the United States and Great Britain. A recent, article, appearing in a British journal, points out that the American miner produces 3 1/2 times as much coal per shift as the miner, at one-half the cost, and proceeds to explain the natural industrial, and engineering causes which lead to this result. Amon« he reasons advanced. is that the American coal miner enjoys the advantage of more easily worked seams of coal, due to the fact that the coal mining industry in the United States is of more recent date than in Great Britain. The latter qualification is not correct, because where these advantages exist, they will persist. The coal beds of the United States are not buried deeply, except in the remote parts of the country, as in the Uinta Basin of Utah. The article referred to states that many of our miners are still employed on out seams reached by "adits", (which we term entries), or by vertical shafts of moderate depth. It is probable in fact that the great bulk of the coal of the United States is taken out from a depth of less than 400 feet.

Mar 1, 1920

By Michael J. Brnich

On November 20, 1968, a massive explosion rocked the underground workings of Mountaineer Coal Co.?s Farmington No. 9 Mine in West Virginia. Of the 99 miners who were working in the mine at the time of the explosion, only 21 survived and escaped the mine. This group included eight who were rescued from the Mahan?s Run air shaft. Nearly 40 years after the event, researchers from the NIOSH Pittsburgh Research Laboratory conducted oral history interviews with two of the eight survivors rescued from the shaft. The Farmington No. 9 Mine disaster ultimately led to passage of the Federal Coal Mine Health and Safety Act of 1969 (amended in 1977).

May 1, 2009

By B. T. Brady

Laboratory measurements by the Bureau of Mines indicate that failure in dry rock specimens measuring approximately 13 cm in length is preceded by tilt anomalies lasting a few milliseconds. The tilt behavior is qualitatively similar to that reported to precede earthquakes. Test results suggest that the time duration of this tilt anomaly for laboratory specimens of this length is independent of rock type, in agreement with theoretical predictions and other experimental data on rock failures including earthquakes.

Jan 1, 1975

By G. W. Reimers

Metastable pyrophoric wüstite (FexO, with x between 0.89 and 0.95) was found to be much easier to grind to colloidal state than were its stable disproportion products magnetite or iron. The grinding of polycrystalline magnetite appears to be complicated by the magnetic flocculation arising from interparticle attraction. This is superimposed on the attraction of a fluctuating electric dipole for a neighboring induced dipole. More than 85 pct of the tumbling time was saved by grinding antiferromagnetic wüstite instead of the ferrimagnetic oxide of iron (Fe304). Disproportionation of colloidal wüstite to the stable ferromagnetic and ferrimagnetic colloidal particles of alpha-iron and magnetite, respectively, was accomplished rapidly at temperatures above 250° C but below 570° C, the eutectoidal stability point of the wüstite phase.

Jan 1, 1972

By Jan M. Mutmansky, Christopher J. Rise

"One of the most serious long term health problems associated with underground,mining is Coal Workers Pneumoconiosis (CWI'), more commonly known as Black Lung Disease. It occurs in some coal workers, normally after 15 or more years of exposure to coal mine dust, and leads to a variety of respiratory problems. Two types of pneumoconiosis are recognized simple CWP, which has been estimated to affect 6.9 percent of miners and is a condition that does not impair the miner's ability to work nor reduce life expectancy; and a more severe form of black lung (called progressive massive fibrosis) that occurs in about one percent of the cases and results in severe lung damage.Although the relationship between coal dust and CWP has long been recognized, detailed knowledge of the relationship is insufficient for setting up authoritative guidelines to reduce the health risks for those employed in dusty,underground environments. CWP is not only a health problem for workers that causes considerable distress, it is also a very expensive problem the total annual costs associated with CWP approach two billion dollars.As part of its efforts to combat CWP, the U.S. Bureau of Mines in 1983 established a Generic Mineral Technology Center to carry out basic research into all aspects of respirable coal dust:— control of dust generation — the behavior of dust in the mine — characterization of dust particles interaction of dust and lung— the relationships among dust generation and mobility and the mine environment, geology, and seam characteristics,Penn State, West Virginia University, the University of Minnesota, and the Massachusetts Institute of Technology are involved in this research, which is administered from the Department of Mineral Engineering at Penn State.Our work is one of the seven projects to be conducted at Penn Slate. We are concerned particularly with the characterization of dust and its relationships with the mine environment, and our main goal is to establish standard procedures for describing and measuring these variables.Coal DustCoal dust is a very complex material that varies greatly in chemical and mineralogical properties. Moreover, it is not the only constituent of respirable dust in the mine. When a coal seam is mined, it is inevitable that rock particles other than coal are included in the material. This rock comes from the mine roof, the floor, and the partings and inclusions within the coal scams. Since the roof and floor strata, the partings and inclusions are often stronger than the coal, mining them frequently causes more dust than mining the coal itself. One of the objectives of our research is to find the relationships between a specific coal's characteristics before it is mined and the respirable dust characteristics after it is mined. We are particularly interested in the size distribution of particles, the chemical properties, and the mineralogical properties."

Jun 1, 1988