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By Henry H. Ginsberg

The Federal Bureau of Mines made pilot plant investigations of the process requirements necessary to produce heavy fuel oil by the liquid-phase hydrogenation of bituminous coal. The investigation was carried out in three separate series of experiments. The first series studied the effect of temperature and contact time on product distribution at 3,500 p.s.i.g. and 420° to 480° C. in the presence of 0.1 wt.-pct../ stannous sulfide plus 0.05 wt.-pct. iodoform based on gross coal. As a result of increased contact times and temperatures, the conversion-6/ and yield of hydrocarbon gas increased, the viscosity of product oil decreased, and elimination of oxygen, nitrogen, and sulfur from coal increased. The yield of oil did not indicate any definite trend with changes in temperature and contact time. The yield of oil ranged from 76 to 85 pct. for Pittsburgh coal and from 60 to 85 pct. for Rock Springs coal. Asphaltenes in the product oil ranged from 17 to 38 pct. of the total oil for Pittsburgh coal and from 12 to 22 pct. for Rock Springs coal. Fuel oils meeting Bunker C or American Society for Testing Materials (ASTM) Grade 6 specifications were produced with Rock Springs coal at 0.2- to 1.0-hr. contact time and 440° to 480° C. and with Pittsburgh coal at 0.3- to 1.0-hr. contact time and 420° to 460° C. In the second series of experiments tin, nickel, iron, and zinc were evaluated as catalysts for the hydrogenation of Rock Springs coal to heavy fuel oil at 3,500 p.s.i.g. and 460° C. Using the apparent conversion of coal as criterion of catalyst activity, at a contact time of 0.45 hr. tin was the most effective catalyst; nickel and iron were nearly as effective, but the use of zinc resulted in much lower conversion. When the contact time was increased to 0.80 hr., the apparent conversion of coal was essentially the same for each of the catalysts. When the yield of oil boiling below 3550 C. was used as criterion of catalyst activity, at 0.45 hr. the order of activity was tin, iron, nickel, and zinc; at 0.80 hr. tin was far superior and the others were essentially equal. The product oils contained from 8 to 20 pct. asphaltenes.

Jan 1, 1960

By W. W. Adams

In mining coal, the Nation's principal mineral fuel, loss of life has been much lower recently than in earlier years when coal mining contributed so heavily to the industrial-accident death toll in the United States. Particularly notable has been the relatively small number of deaths during the past few years compared with the number that occurred 20 or 30 years ago. Reports received by the United States Bureau of Mines, covering all commercially operated mines that were active during all or any part of the calendar year 1935, showed that accidents during that year had resulted in the loss of 1,242 lives. This death toll, although regrettable, represents a material improvement over the industry's experience during most years prior to 1935, and especially over the industry's worst year, 1907, when 3,242 men were killed. Fewer lives were lost in 1933, when 1,064 men were killed at work, than during any year for which complete figures are available.

Jan 1, 1938

By P. R. Perry

This publication is a compilation of tested methods for the analyses of titanium tetrachloride, titanium sponge, and various intermediate materials and products. They are presented in concise form without the detail usually found in publication of new methods because many of them are modifications of well known procedures. The Electrometallurgical Experiment Station, Boulder City, Nev., has been developing titanium production methods since 1945. Most of this development was on a modified Kroll Process but also included work on sodium reduction and electrolytic methods. During these years a large variety of samples were analyzed. Most of the analytical problems were solved using published methods or modifications of the same. At the start, there were no published procedures for analyzing titanium sponge using spectrochemical methods. A great deal of study was given to testing several of the well known techniques, and some of them, such as direct sparking of the metal, proved to be completely unsatisfactory. Solution-spark techniques were finally tried, and satisfactory procedures were developed for some of the more common impurities. These spectrochemical methods were then put into routine use for several months before their publication.2/ Some new modifications have been made, and techniques have been developed to determine other impurities found in titanium sponge and tetrachloride. All spectrochemical methods used in 1954 are included in this publication.

Jan 1, 1955

By Jan Zwarcendyk

This study is primarily directed toward providing an understanding of the economic complexities associated with subsidence damage on the surface resulting from underground mining. Some of the pertinent theories on the physical stresses involved are reviewed, and both remedial measures and relevant laws in various countries are discussed. Part I (Chapters 1-3) is an historical overview of various aspects of subsidence problems (theoretical, remedial, and legal) during pre-World War I, between World Wars, and post-World War II, respectively. Part II (Chapters 4-9) presents a comprehensive analysis of the economic aspects of subsidence in relation to the following mining alternatives: (a) carrying out the lowest cost mining method without regard for any surface subsidence, (b) special mining techniques, (c) partial mining, (d) full recovery with stowing, and (e) sterilization or leaving the mineral unmined beneath selected areas. These alternatives are evaluated in terms of their measurable expenses.

Jan 1, 1971

By Clarence A. Wright

The Missouri-Kansas-Oklahoma lead and zinc district, better known as the Joplin district, includes the mines in southwest Missouri and in those parts of Kansas and Oklahoma that are directly adjacent. (See PI. I.) This report of investigations carried on by the Bureau of Mines gives the methods used in mining and milling and indicates in some detail the conditions that affect the efficiency of those methods; it does not attempt to discuss the geology of the district, except incidentally, as this has been described in numerous reports by several geologists. Some of the more important recent publications are those of the United States Geological Survey by Smith and Siebenthal, a Bain, b and also those of the Missouri State geological survey by Buckley and Buehler." Other reports are those by Schmidt and Leonard," and Winslow,e of the Missouri geological survey, by Haworth and Crane,! of the Kansas geological survey, and by Jenney.g Although the lead and zinc ores are closely associated, the proportion of zinc ore mined at present is far greater than in former years. For this reason and because the losses in milling zinc ores are proportionately greater than in milling those of lead, the zinc ores are here given most consideration. Only the mines and mills actually examined and tested are discussed in detail, statements of results being restricted to the mines in general, with no special reference to anyone mine. Several mill tests were made to determine in a general way the efficiency of the milling practice in this district and to discover at what stage of the process the losses were greatest. Making these mill tests proved difficult,for, because of the arrangement of the mills and the necessity of estimating the tonnage treated, systematic mill testing and sampling can be done at only a few plants. Many tables giving results of mill tests and screen tests have been omitted because they would serve only to emphasize the important points shown by other data given. The writer has tried to bring out the possibilities of making certain improvements that would effect a greater saving, and has endeavored to avoid the use of technical terms and phrases in order that all statements may be clear and easily understood.

Jan 1, 1918

By M. E. Tyrrell

This Bureau of Mines investigation was made to determine the possibilities of using Florida beach-sand concentrator wastes in ceramic products. Sands used in the investigation originated in the Trail Ridge area of Florida, where continued operation of processing plants for recovering titanium minerals promises a dependable source of raw materials. Three general classes of ceramic products were studied, namely: (1) Structural, (2) refractory, and (3) electric-furnace slags.

Jan 1, 1956

By Paul T. Alexander

After evaluating preceding studies and designs of lightweight supports, ESD selected the all-hydraulic and the hydromechanical concepts for detailed design and fabrication. Further analysis and testing showed that the all-hydraulic design was economically justified and met all the crucial engineering, manufacturing, and design criteria identified during the evaluation phase. Following Bureau of Mines approval of the detailed design, four all-hydraulic support models were fabricated. Once functional and structural testing was successfully completed, 40 additional units were constructed and distributed for in-mine testing. The units were very well-liked by all three demonstration mines. The wide- spread interest in supports for seam heights greater than 8 feet led to expansion of the design data package. ESD designed four basic models to cover the new height range, but no hardware has yet been fabricated for the new design.

Jan 1, 1982

By Margaret R. Egan

The U.S. Bureau of Mines conducted experiments in the intermediate-scale fire tunnel to assess the influence of air velocity on the gas production and smoke characteristics during smoldering and flaming combustion of Pittsburgh seam coal and its impact on the detection of the combustion products. On-line determinations of mass and number of smoke particles, light transmission, and various gas concentrations were made. From these experimental values, generation rates, heat-release rates, production constants, particle sizes, obscuration rates, and optical densities were calculated. Ventilation has a direct effect on fire detection and development. The results indicate that, in general, increased air velocity lengthened the onset of smoke and flaming ignition, increased the fire intensity, but decreased the gas and smoke concentrations. Increased air velocity also lengthened the response times of all the fire sensors tested. Rapid and reliable detector response at this most crucial stage of fire development can increase the possibility that appropriate miner response (fire suppression tactics or evacuation) can be completed before toxic smoke spreads throughout the mine.

Jan 1, 2010

By Henry Kreisinger, WALTER T. RAY

This preliminary bulletin was written as the first of a series of several on the significance of drafts in steam-boiler practice, the succeeding bulletins to be along the same lines but of a more advanced character. The conclusions arrived at are tentative, and are the result of a study of one of the many problems growing out of a general plan of the United States Government to increase the efficiency with which the coals of the country are being used. Greater efficiency requires better boiler and furnace design. The experimental study of drafts on which the conclusions presented in this bulletin are based formed part of the fuel-testing investigations that were carried on by the technologic branch of the United States Geological Survey and have been transferred to the Bureau of Mines. The experiments made seem to indicate that it is possible to double or treble the capacity of a plant without making any radical changes the furnaces and boilers. These increases require about double and treble the quantities of air to be put through the fuel beds and boilers. It also seems probable that rebafHing the boilers will often permit the capacity to be doubled or trebled, while still getting more steam than formerly per pound of coal for uses outside the boiler room. These experiments were undertaken with the object of clarifying ideas concerning the passage of air through fuel beds and boilers. Measured weights of air were passed through two beds of lead shot, series, one of which remained always the same and represented a boiler; the other being varied as to size of shot and depth of bed, and representing a fuel bed. Careful observations were made of the weight of air passing through the beds per minute. All data were plotted in many charts, so as to permit the study of them from several points of view. A number of laws were deduced bearing on the relative amounts of power required to force air through fuel beds of various thicknesses, composed of various sizes of coal, and through boilers of various lengths and areas of gas passages. An important part of the discussion relates to an increase in the capacity of boilers by increasing the amount of power applied to pressure and exhausting fans and thus forcing several times as much air through the fuel beds and boilers. may be possible, as a result of these investigations, to raise the rate of working the boiler heating surface to three or even four times its present value. Such an increase would undoubtedly mean new designs of grates, stokers, furnaces, and boilers, especially fitted for high rates of working. Fan equipments designed to supply three or four times as much air under several times the pressure would be provided with more efficient engines, thus giving an additional factor favoring high-capacity working. It must be borne in mind, as stated above, that the results are tentative. It will cost money to force gases at high speeds through fuel beds and boilers, and there will soon be pressing need of such quantitative data as will enable the largest possible part of the energy imparted by the fans to be advantageously utilized. We desire, to thank our superiors, especially Messrs. L. P. Breckenridge and D. T. Randall, for their helpful criticism and suggestions.

Jan 1, 1911

By Steven R. Davis

Voyageurs National Park in northern Minnesota, and a 30-mile radius area of influence on the United States side of the International Border, was examined for hardrock (nonferrous metallic minerals and diamonds) mineral potential and environmental sensitivity by the U.S. Bureau of Mines. The investigation also included an analysis of current Metallic Minerals Leasing Rules of the State of Minnesota, and the probable effects of changes proposed to the current rules by the State of Minnesota in order to "encourage mineral exploration and development." The study has determined that the proposed changes to the Minnesota State Leasing rules will have minimal, if any, impact on the likely, foreseeable levels of mineral-related activities in the State as a whole, and particularly, in the area of influence to the Park. Voyageurs National Park management was advised on the extent and character of the proposed rules changes, and on those items of concern meriting a specific and timely response by the National Park Service.

Jan 1, 1994

By G. L. Bartlett

"INTRODUCTION The major objective of our research is to help reduce the incidence and severity of coal worker's pneumoconiosis (CWP). To that end, this project is designed to improve our understanding of the processes that lead to pulmonary dysfunction following mine dust exposure, and how those processes might be interrupted or attenuated. The response of the lung ' to inhaled particles is complex, and the course of development of disabling CWP is slow and unpredictable. From among the numerous cellular and molecular interactions involved in the pulmonary response to inhaled particles, this project is focussed on the role that the pulmonary alveolar macrophage (PAM) may play in regulating the activity of fibroblasts.The PAM is the lung cell that has the most immediate and the most obvious interaction with inhaled particles. Within a short period after particles are arrested in the alveolus of the lung, they are phagocytized (engulfed) by these specialized cells. The PAM then has a diverse potential repertoire of subsequent activities. Which reaction actually ensues is determined, in large part, by the nature of the phagocytized _particles. Activated PAMs produce a variety of products that may affect adjacent lung tissue, including superoxide free radical, elastase, collagenase, prostaglandins, platelet activating factor, etc. Those may well be important in the pathogenesis of CWP, but they are beyond the scope of this project. Background information that is cogent to this project has come primarily from investigations using animal models of silicosis and asbestosis. PAMs that have ingested silica particles synthesize and release molecules that control the behavior of surrounding cells. One such mediator is interleukin-1 (IL-1), a molecule that plays a central role in many aspects of the response to injury. It can stimulate fibroblasts (the cells that help to hold tissues together) to release the enzyme collagenase, resulting in breakdown of the structural collagen fibers that support the lung tissue. IL-1 also stimulates fibroblasts to undergo mitosis and to proliferate, which is an initial stage of fibrosis. Certain stimulants cause PAMs to release fibroblast growth factors (FGFs) that are distinct- from IL-1. Under other circumstances activated PAMs synthesize and release molecules that stimulate fibroblasts to accelerate synthesis of collagen fibers, thus contributing to fibrosis. Although these observations provide a valuable precedent for analysis of the mechanisms involved in CWP, their relevance to CWP cannot be assumed since most of those studies involved macrophages or fibroblasts obtained from tissues other than the lung, and because almost none of them have used CMD as the stimulating particles. Therefore, the goal of this project is to learn how exposure to CMD affects the behavior of PAMs, and in turn how products of dust-exposed PAMs affect fibroblasts and the process of fibrosis in the lung."

Jan 1, 1988

By Margaret R. Lickes

Mercury was produced originally at the Idaho Almaden mine from 1939 to 1942. When the ;.nine was shut down, more than 100,000 tons of ore, containing from 2.5 to 3 pounds of mercury per ton, was known to be adjacent to old workings but had been considered too low grade for commercial operation. Later, detailed, systematic exploration by Rare Metals Corporation of America increased and delimited enough minable reserves for further operation to be foreseen for several years. The average grade of the ore is estimated at slightly more than 3.5 pounds of mercury per ton. Open-pit mining and installation of the largest rotary kiln in the United States furnacing mercury ore have made possible profitable exploitation of these reserves (fig. 1). The bulk of the exploration was by percussion drilling, although some diamond drilling was done to check the results. When enough reserves were indicated to assure a successful operation, stripping and plant construction were started simultaneously. Figure 2 is a general view of the plant. The ore bodies, although irregular in size, shape, and grade and covered by essentially barren cap rock, are amenable to low-cost, trackless, open-pit mining. Development consists of stripping the overburden and removing, barren cap rock. Ore is being mined at approximately [5],000 tons per month and treated in a 175-ton-per-day furnacing plant.

Jan 1, 1957

By A. R. T. Denues

"INTRODUCTION The Explosives Division of the Bureau of Mines, United States Department of the Interior, is investigating cushioned blasting at the Explosives Testing Station, Bruceton, Pa. The general interests of this investigation are practical and relate particularly to safety. The immediate concern is an application of cushioned blasting in coal mining.In cushioned blasting, various means are employed to reduce the intensity of the application of energy in an explosive action in a borehole. The primary object is to increase the efficiency of the use of explosives. Cushioned blasting is designed to save the energy usually lost in excessive shattering and in this way to effect economies and to produce increased proportions of desirable lump coal. That this saving should lead to greater efficiency is indicated by an analogy with the theory and experience of size-redaction by crushing or grinding from which it is known that a large proportion of the energy consumed is expended in producing the smaller sizes (26),3/. Aside from these considerations, increasing the yield of lump coal is important in practice because larger sizes of coal usually sell at higher prices. Some statistics published in England in 1934 (63) illustrate the economic origin of the interest in increasing yields of lump coal; these indicate for three sizes of coal that as the size decreases the value decreases in the approximate series 3:1.5:1, thus:"

May 1, 1940

By Floyd G. Anderson

This report reviews and summarizes information on prevention and suppression of dust in mining, tunneling, and quarrying published in the United States from 1961 through 1967. Unpublished pertinent data developed or assembled by the Bureau of Mines during this period also are included.

Jan 1, 1969

By Paul S. Goodman

This report examines the effectiveness of bonus plans in the coal industry. The analysis uses theoretical, literature review and empirical approaches to determine the impact of bonus plans on safety and productivity in underground coal mines. The basic finding is that the modal bonus plan in underground coal mining does not have a major impact on productivity and safety indicators. The design of the plan, or organizational factors, and the process of introducing the plan all contribute to its relative ineffectiveness. Strategies and options for designing effective plans are presented.

Jan 1, 1987

By K. K. Kelley

This work is a continuation of a program of study of the measurement and correlation of fundamental thermodynamic data inaugurated several years ago by the United States Bureau of Mines. Previous bulletins in this series were concerned with (1) The Entropies of Inorganic Substances (66),3 (2) High-Temperature Specific-Heat Equations for Inorganic Substances (67), (3) The Free Energies of Vaporization and Vapor Pressures of Inorganic Substances (68), (4) Metal Carbonates-Correlations and Applications of Thermodynamic Properties (71), (5) Heats of Fusion of Inorganic Substances (69), and (6) A Revision of the Entropies of Inorganic Substances-1935 (70). The present bulletin has as its primary purpose the correlation of the thermodynamic properties of elementary sulphur and its inorganic compounds and the presentation, after careful consideration of all available information, of a self-consistent system of thermodynamic relationships for these substances. It is believed that such a set of relationships, concerning substances of such great metallurgical importance as sulphur, sulphur oxides, hydrogen sulphide, metal sulphides, and metal sulphates, is of considerable value in indicating directions of possibly profitable experimental work and in clarifying subjects of technical interest upon which direct experimental information is difficult and expensive to obtain. It cannot be doubted that many problems of technical importance that at the outset appear almost hopelessly complex or obscure either may be solved, if enough information is available, or the specific lacking information clearly indicated by the adoption of the thermodynamic viewpoint. This has been demonstrated many times in the work of the Metallurgical Division, Pacific Experiment Station, Berkeley, Calif. Even when only crude basic information is available, a semiquantitative picture often may be developed by thermodynamic means in which general trends and approximate limits of a proposed process or modification of practice may be clearly portrayed and thus used as guides in further considerations and experimentation.

Jan 1, 1937

By V. F. Parry

The major industrial uses of char or semicoke produced by low-temperature carbonization of coal4/ are as fuel for generating electric power, for blending with metallurgical coking coal as a substitute for low-volatile coals, and for gasification to produce synthesis gas for chemical purposes. This paper discusses various methods for carbonizing coal, emphasizing processing of the noncoking coals to produce char for thermal power-plant fuel and for blending with metallurgical coking coals and tar for chemical use. Low-temperature carbonization is a relatively simple processing step involving heating coal to about 900° to 1,200° F. to decompose the coal into 4 main products: (1) Semicoke or char; (2) complex, partly oxygenated liquid hydrocarbons or tar; (3) fixed gases; and (4) water. If the coal is heated rapidly under conditions that prevent decomposition of the primary products, 68 to 87 percent of the net heat in the raw coal is left in the char and 10 to 23 percent of the potential heat appears in the primary tar. Fixed gases represent approximately 7 percent of the heat and approximately 2 percent is lost or dissipated in the reactions of decomposition. Considering the different ranks of coal in the United States, the yield of tar will vary from about 9 to 44 gallons per ton, therefore it is important that each coal be carefully considered if it is to be carbonized for industrial use.

Jan 1, 1955

By B. J. Moore

This publication contains analyses and related source data for 252 natural gas samples from wells and pipelines in 17 States. All of the samples were obtained and analyzed during calendar year 1976 as a part of Bureau of Mines investigations of the occurrences of helium in natural gases of countries with free market economies. This survey has been conducted in the United States by the Bureau of Mines since 1917. In late 1965, the survey was expanded to include foreign gasfields. The analyses published herein were made by mass spectrometer and a special helium analysis apparatus, which are described in Bureau of Mines Bulletins 4862 and 576.3 The results of the investigation of the occurrences of helium are published annually to make the information available as soon as possible to the gas industry and the public in general. Eighteen previous publications have presented the results of 11,065 gas analyses prior to 1976. The first 3, Bulletins 486,4 576,5 and 617,6 contain analyses and related source data on 5,218 gas samples collected from 1917 through 1960. The other 15

Jan 1, 1977

By W. R. Hardwick

This information circular describes mining methods and practices at New Cornelia Branch, Phelps Dodge Corp., Ajo, Ariz. It is one of a series being prepared by the Bureau of Mines on mining methods, practices, and costs in various mining districts of the United States. The New Cornelia mine (fig. 1) is at Ajo, a town in southwestern Arizona (fig. 2) on Arizona State Highway 85 in the western part of Pima County. The [oncentrator] and smelter are near the mine (fig. 3). Copper ore is mined, crushed, ground, and concentrated, and the concentrates are smelted. Copper is cast in anode form and sent to the Phelps Dodge Corp. refinery in El Paso, Tex.

Jan 1, 1960

By Anthony D. Szpak

The purpose of this program was to demonstrate the feasibility of Illuminating various types of underground coal mining machinery as required by the Federal Coal Mine Illumination Standards Part 75.1719 to 75.1719-4 Code of Federal Regulations Title 30. Nine various machines were illuminated and the illumination systems were evaluated for a 3 month period of operation. Factors evaluated were ease of implementation, reliability, ease of maintenance, acceptance by mine workers and operators, Illumination degradation and durability.

Jan 1, 1981