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By Louis H. Berkelhamer

"INTRODUCTION The method of differential thermal analysis suggested by Le Chatelier (1)1 in 1887 has recently emerged as an outstanding means of studying the constitution of various substances, particularly clays, soils, and miscellaneous hydrous materials (2). The literature ably discusses the applications and results obtained but has paid too little attention to specific details of construction of the apparatus. Knowledge of the apparatus is of importance to the experienced research man as is extremely useful to the novice v ho ventures into this field of analysis. Further, it is generally acknowledged that the variations in design and conditions of operation are one of the essential causes for differences in characteristic temperatures as reported by various investigators. A step forward in the elimination of such differences is the publication of the details of construction and operation of a simple and inexpensive apparatus that has proved useful at the southern Experiment station of the Bureau of Mines, where it was used in cooperation with the University of Alabama, Tuscaloosa, Ala."

Jul 1, 1944

From time to time the Bureau of Mines has interpreted and applied certain provisions of the Federal Coal Mine Safety Act and Federal Mine Safety Codes, primarily for the guidance of Federal Coal Mine Inspectors. Although interpretations of the Act have appeared in the Federal Register, the Code interpretations and practical applications have not been published. In response to many requests from representatives of the coal-mining industry, the Bureau is publishing this information to promote better understanding of those provisions that may be misinterpreted or misapplied. INTERPRETATIONS AND APPLICATIONS Two Federal Mine Safety Codes are discussed in this report, namely the Federal Mine Safety Code for Bituminous-Coal and Lignite Mines of the United States, Part 1, and the Federal Mine Safety Code, Anthracite Mines of the United States, Part 1. In this circular the word Codes refers to both directives; Code* refers to the code for bituminous-coal and lignite mines; Code? refers to the one for anthracite mines. Act* refers only to bituminous-coal and lignite mines.

Jan 1, 1963

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 Walter E. Lewis

This circular presents the method of making tests and apparent results of comparing performance of tungsten carbide insert bits and steel detachable bits by the Cleveland-Cliffs Iron Co. at the company's mines on the Marquette iron range of Michigan. The mines are at Ishpeming and Negaunee, Mich., and include the Cliffs Chaft, Mather "A", Cambria-Jackson, and Mather "B". There are four general characteristic types of high-grade iron ore on the Marquette range. B. H. Boyum2/ classifies the Cliffs Shaft as "hard-ore" and the Cambria-Jackson and Mather "A" as "soft-ore" types of deposit. Shaft sinking through Jasper, slate, and graywacke was in progress at this writing at the Mather "B", with completion at 3,100-foot depth in August 1949. The many different kinds of rock and ore at the mines of the Cleveland- Cliffs Iron Co. and the experimental work being carried on with carbide in- sert bits make it possible to compare, generally, the carbide insert and steel detachable bit. The type of "hard ore" at the Cliffs Shaft mine re- quired close study of the possible use of the insert tit, and their records are more complete than those of the "soft-ore" mines. History and development of tungsten carbide tips inserted in rock drill bits have been covered by R. W. Adamson, C. H. Vivian, R. C. Sullivan,5/ and others. Tungsten carbide insert rock bits have only recently been introduced to the domestic mining industry. Although unusual performance records are being reported at operations employing the insert bits, the general adaptability of the tool to all rock types and the advantages to be gained by using carbide insert tits remains to be demonstrated. Insert-bit performance is being observed at numerous mines and quarries throughout the United States The several mining operations at the Cleveland-Cliffs Iron Co. at Ishpeming, Mich., is one site where exhaustive comparative tests of insert and conventional steel detachable bits are currently in progress. Results to date are sufficiently impressive to be of general interest to the mining

Mar 1, 1950

By Lucien Eaton

This paper describing the mining practices at Mine No. 2 of the Marquette Range, Michigan is one of a series being prepared by the Bureau of Mines on mining practices, methods, and costs in the various minim; districts of the United States. The publication, of this information should be of interest to the industry at large and the exchange of ideas thereby made possible should be of economic value to operators in all harts of the country. ACKNOWLEDGMENTS The author is indebted to the superintendent, engineer, and mining captain of the property discussed in this paper for much of the information presented. The geological classification is taken from publications of the U. S. Geological purvey.

Jan 1, 1929

By Nabil A. Bibawy

The U.S. Bureau of Mines has established a method for the calibration of class 2 and class 4 standards of mass using a procedure from designs developed by the National Institute of Standards and Technology (NIST). This method produces a weight calibration that is within 1.0 pct of the balance sensitivity. A set of four 1-kg weights yielded a standard deviation of 3.25 mg compared to ±2.91 mg balance sensitivity. The method employs the use of a high-accuracy balance to measure the difference between a set of weights calibrated by NIST and the set to be calibrated. The error of the balance is included in the error for each weight calibrated.

Jan 1, 1989

By Lloyd A. Morley

A concept is presented to improve underground coal mine electrical system safety and availability. This proposed technique is based upon the ability to predict incipient failures in the mine power system. Prediction is made possible by a new method, developed during this research, which uses a minicomputer to implement pattern recognition algorithms. The theoretical basis of the prediction system is discussed, along with synthesis of the hardware and software sections. The deterioration modes which could be detected are examined, and an evaluation of the system's ability to predict incipient failure is presented. Typical results of the system's performance during laboratory simulation of power system deterioration are given.

Jan 1, 1977

By Frank J. Cservenyak

Curtailment of bauxite importation by enemy activities during World War II focused attention on the necessity of developing domestic deposits of aluminous materials. Large quantities of aluminum ores such as kaolin, siliceous bauxites, high-iron bauxites, anorthosite, and diaspore clays are available but not readily amenable to Bayer processing because of excessive impurities. The Bayer process, which is the only commercial method in use in the United States for producing metallurgical-grade alumina, requires a high Al2O3 bauxite relatively low in SiO2 and Fe2O3. The Bureau of Mines was charged by Congress to investigate processes for the production of alumina from these low-grade ores. One part of the program was an investigation, in the laboratory and pilot plant, of the recovery of alumina by the lime-soda sinter process. Ores comprising kaolin, diasporic clays, anorthosite, and siliceous bauxites have been investigated and studied in the laboratory and pilot plant, and a series 'of reports covering these investigations has been prepared.

Jan 1, 1948

By R. Hogg, S. Chander

"INTRODUCTION The behavior of particulate systems in general is determined by the properties of the solid and fluid phases and of the interfaces between them. As particle size is reduced, the inter facial effects become increasingly important until, in colloidal systems, they become completely dominant. Interfacial phenomena are especially important in coal processing for a variety of reasons. Because coal is naturally hydrophobic and its density is low, surface forces begin to dominate over gravity at relatively coarse sizes. Coal is thermodynamically unstable in the presence of air, so that surface oxidation occurs readily leading to important variations in surface properties with time and environment. These effects are further compounded by the inherent heterogeneity of the material.Surface characteristics and properties play a significant role in most aspects of coal processing. Comminution, for example, is a process of creating new surface, while agglomeration involves the reduction of surface area and is usually controlled by surface forces. Both solid-solid and solid-liquid separations are influenced by interracial phenomena, Gravity separations are usually performed in a liquid phase and are affected by the wetting characteristics of the various solids present and by the need to ensure proper dispersion of the individual particles. Froth notation, of course, separates particles on the basis of differences in surface characteristics. Chemical processes such as leaching generally involve interfacial reactions whose rates depend on surface area and may be influenced by electrochemical effects in the electrical double layer at the solid-liquid interface, or by adsorption of reactant and/or product species from solution. Solid-liquid separations and associated processes such as flocculation are strongly dependent on the nature and properties of the solid-liquid interface.In characterizing solid surfaces, it is important to consider first the surface area, since this determines the relative importance of the interfacial effects. The structure and chemical composition of the surface may depend on the distribution of different petrographic constituents and impurities such as finely disseminated mineral matter, on the extent of surface oxidation, and on adsorption from the environment. These, in turn, will generally determine the surface properties which define particle behavior. Since the relationships between structure etc. , and properties are not generally known, it is usually necessary to measure properties such as wettability and electrical charge directly."

Jan 1, 1989

By William C. Cooley

This volume contains copies of the 5 x 8 in. accession card file for all items collected which were judged to be relevant to underground hydraulic coal mining. In many cases, abstracts are included. Abstracts were taken from the source, from other reviews, or from the preliminary screening of Russian documents performed by Dr. A. L. Brichant. No attempt was made to write abstracts for every accession item.

Jan 1, 1975

By J. Douglas Causey

In 1986, at the request of the Bureau of Land Management, the U.S. Bureau of Mines studied the 7,940-acre Southern Otay Mountain Wilderness Study Area (CA-060-029), and the 5,750-acre Western Otay Mountain Wilderness Study Area (CA-060-028) in order to evaluate their mineral resources. The wilderness study areas are located in San Diego County, CA, about 20 miles southeast of San Diego. No mineral resources were identified in the Southern or Western Otay Mountain Wilderness Study Areas, based on literature, field observations, and sample results. The wilderness study areas are underlain by a complex blend of Late Jurassic, moderately metamorphosed sedimentary and volcanic rocks. Evidence of mineralization is not obvious.

Jan 1, 1987

By Robert A. Jankowski

The U.S. Bureau of Mines, in cooperation with the Mine Safety and Health Administration (MSHA) and the mining industry, has identified and demonstrated the effectiveness of several improved face ventilation techniques for longwall mining systems. These include the following: identifying improved techniques for measuring face ventilation parameters on longwall sections, installing curtains at the intake end of the longwall face to maximize usage of the primary airflow, identifying optimum face airflow rates for maximizing dilution effects, and coursing the primary face intake from tailgate to headgate to minimize outby airflow contamination. Application of these techniques throughout the mining industry should reduce the health hazard associated with excessive exposure to respirable coal mine dust.

Jan 1, 1993

By P. W. Jeran, M. C. Irani, Maurice Deul

This Bureau of Mines survey of methane emissions indicates that total daily emissions have declined from 227 MM ft3 in 1971 to 214.7 MM ft3 in 1973. The highest average daily emissions in million cubic feet per day observed in U.S. bituminous coal mines were, in decreasing order, Monongalia County, W. Va. , 40.7 ; Marion County, W. Va. , 23.1 ; Buchanan County, Va. , 22.1; Washington County, Pa., 12.4; Greene County, Pa., 11.7; McDowell County, W. Va. , 11.4; Cambria County, Pa., 9.8; Jefferson County, Ala. , 9.5; Wyoming County, W. Va., 6.0; Marshall County, W. Va., 4.8; and Indiana County, Pa., 4.8.

Jan 1, 1973

By Thomas P. Mucho, Dennis Dolinar, Christopher Mark

During the 1990s, the former U.S. Bureau of Mines conducted a number of field studies in which the performance of different types of roof bolts were evaluated in different geologic environments. The studies used a standard suite of measurements, including multipoint extensometers, strain-gauged roof bolts, and roof bolt load cells. The sites were chosen to investigate the effect of a variety of parameters, including installed tension, bolt capacity, grout annulus, and horizontal stress orientation. Although not fully successful, the measurements provided valuable insights into each of these issues. They also showed that instrumentation and monitoring have important advantages over observational methods for comparing the performance of different roof bolting systems.

Jan 10, 2000

By Launa G. Mallett, Kathleen M. Kowalski, Michael J. Brnich

The characteristics of leaders under the duress of an emergency are important in the development of emergency planning, training, and in the management of an actual emergency. Knowledge of human behavior is an important component in the formation of emergency strategies. The U.S. Bureau of Mines analyzed the leadership behavior in three underground mine fire escapes. The subjects described their escapes during open-ended interviews. Data were coded according to: (1) evidence of leadership behavior, (2) evidence of lack of leadership behavior, and (3) characteristics of the individual in each group who led the subjects out of the mines. This paper discusses the profile of six individual leadership characteristics which emerged from the data.

By R. R. Sayers

The terms "sanitation and }\Vgienen are often used interchangeably, but it is more "' usual to apply ttsani tat ion'' to th environment or surroundings, and nr.ygieneto the iiiividual, The subject,. h9wever, is so broad that only a few of the phases of sanitation will be di.acusae in ·this paper, vmile the various Fsea of hyg:tene will be deferred for later consideration. One of the bes.t .iaf ini tions of sanitation that I have hearci was given by ur. L. L • Lumsden, of the U, S. Public Heal th Service, who state.d that "'sanitation is t-he c.oir .. 'Don-sens$ application of the principles of cleanliness,

Aug 1, 1922

By Jack E. Fraley

Poor lubrication reduces the life of wire hoist ropes when they are used in corrosive environments. Although lubricants are added to ropes during the manufacturing process, these lubricants can deteriorate during use, and it is often necessary to add more lubricant to both the interior and exterior of the rope while it is in service. The U.S. Bureau of Mines evaluated the effectiveness of synthetic lubricants, using electromagnetic nondestructive testing (NDT) to measure deterioration in ropes while they were in service. For nonpressurized lubricant applications, synthetic lubricants appear superior to petroleum-based lubricants in their ability to penetrate to the interior of a rope. Therefore, the synthetics offer better wear and corrosion protection.

Jan 1, 1990

By R. V. Ramani

"In Part 1 of this two-part paper the characteristics of mine disasters and their effects are presented with case studies from coal, metal and non-metal mines leading to an amplification of their causes and opportunities for control. The disasters discussed encompass those which threaten the health and the safety of miners and those which affect the general population. In Part 2 of the paper, which will be published in the November 1995 issue of Natural Resources Forum, the approaches to hazard and disaster control are reviewed with particular attention to laws and regulations to promote health and safety at the workplace, and general welfare in mining communities. Further, a systems approach to disaster control is outlined.The mining industry is one of the three basic industries the other two being agriculture, and wildlife and fisheries. It is the process of mining which makes available the riches of the earth - the energy and mineral resources - to benefit humanity. In fact the progress of the human race through the ages is indelibly attached to prowess in exploiting these riches. The stone, iron and bronze ages are markers not just of a time in history but achievements of monumental proportions in the mining and beneficiation of natural resources. Even in agriculture, the remarkable success stories are associated with the prudent use of mined products to enhance production and productivity. The significance of a thriving mining industry to the wealth and security of a nation is therefore unquestioned.Unfortunately, the public's image of the mining industry is often associated with the mining disasters which receive wide coverage in the local and national media. Mine disasters command tremendous attention because of their infrequent occurrence and the extent of human suffering involved. Whether it is an explosion or a fire, or the opening or closing of a mine, the lives of people are touched by the personal and societal impacts of these events.Courts of inquiry of mining disasters have often concluded that the disaster situation was ever present and could have been detected with diligent search. In addition human error has been identified as one of the most frequent immediate causes for the precipitation of the disaster. For the most part, then, mining disasters are caused by man."

Dec 1, 1996

By J. M. Mutmansky, R. A. Jankowski, M. A. K. Mohamed

"SYNOPSISKnown health hazards associated with the breathing of respirable dusts, particularly silica dust, during mining are becoming a great concern in many parts of the world. The search for effective and low cost dust control methods for underdeveloped countries will help in improving the productivity and keeping the mine environment safe. This article addresses the problem by providing suggestions concerning the easiest and most cost effective methods to control respirable dust in mining and mineral processing operations. INTRODUCTIONMedical BackgroundLung diseases caused by dust in mining operations have been recognized by mankind since the time of the Roman Empire. The writings of Pliny the Younger on natural history reported on maladies associated with dust in mining in the first century AD. However, no significant advances in controlling the lung diseases of miners came about for many centuries. The effects of mineral dusts were further described by Georgius Agricola in his sixteenth century book on mining (Agricola, 1556). After the appearance of Agricola""s book, lung diseases were more readily recognized, but the nature and severity of the ailments associated with mineral dusts could not be readily interpreted.In 1896, the discovery of x-rays by Roentgen advanced the diagnosis of lung diseases and the knowledge of what causes these diseases. In addition, the discovery allowed medical personnel some method of judging the extent and severity of the lung diseases in human beings. During the ensuing years, the term 'pneumoconiosis' became the common term to describe any of the diseases of the lung in which dust particles deposited in the lungs caused fibrous tissue and loss of some of the respiratory function. However, little in the way of social remedies for the diseases resulted until much later. Society was still not ready to act decisively to reduce the causes of lung disease due to the dusty conditions in the work place.Social action against lung diseases did not occur in the United States (US) until the 1930s. At that time, a tunnel driven through a sandstone mountain near Gauley Bridge. West Virginia, caused the death of several hundred workers due to acute silicosis, a severe form of pneumoconiosis caused by silica (Seaton, 1975). Dust conditions in this tunnel were quite bad, causing many of the workers to be subjected to extremely high silica dust concentrations. The severity of the disease in many of the workers became known to the public and prompted the US Congress and many of the states to enact laws to reduce the dust levels."

Jan 1, 1998

By M. K. Larson, J. K. Whyatt, F. M. Jenkins

The U.S. Bureau of Mines conducted an overcore stress measurement on the 5300 level of the Lucky Friday Mine, Mullan, ID, to investigate the stress regime around an experimental stope in a rock-burst-prone mine. The result indicated a stress field with unexpected magnitude and orientation [F . 135 MPa (19,600 psi) oriented S 80E1W]. An unusual amount of rock-burst activity was encountered during subsequent excavation. A careful review of the overcore data suggested the overcore strain measurements were valid. Moreover, concentrated rock-burst activity suggested that the measured stress field did exist, but was localized and therefore did not represent the far-field in situ stress field.

Jan 1, 1995