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By Michael W. Redifer

A Fortran IV computer program was developed to calculate the composition at equilibrium of products from a set of high-temperature gas combustion reactions. The program was used to develop high-temperature equilibrium concentration profiles for various constituents as a function of temperature and oxygen concentration. The computer program was specifically applied to reactions pertaining to the corrosion of superheater tubes in pulverized coal-fired boilers; however, it is useful for any multicomponent, multireaction scheme in which equilibrium constant data can be obtained and is comprised of gaseous reactants along with finely dispersed solids or liquids. General applicability of the computer program, including its limitations, are discussed along with detailed instructions for using the program.

Jan 1, 1973

By Eldon Keith Stanek

This annual report deals with a multi-faceted research effort to increase mine electrical system safety. The project can be broken down into six task areas. Task one deals with the development of tests and instrumentation to perform these test- that are designed to detect incipient faults on mine power systems. This program also encompasses evaluation of the tests and automation of data collection and recording using a microprocessor. Task two concerns the prediction and suppression of mine electrical transients. This program involves digital simulation and suppression hardware evaluation. Task three deals with the reliability and fail safe assessment of various components of the mine electrical system including both the protective system and bulk power system components. Task three deals with theoretical analysis, laboratory testing and in-situ testing in coal mines of power system devices. Task four is an effort to design an optimal mine electrical distribution system. The initial effort is along the lines of refining analytical tools such as the load flow model. Task five is an attempt to optimize the selection of molded case circuit breakers makes or models on the basis of total annual cost. Task six assesses the availability of equipment to satisfy existing federal regulations.

Jan 1, 1977

Kroemer(1-3) and Kroemer et al.(4) define the isoinertial technique of strength assessment as one in which mass properties of an object are held constant, as in lifting a given weight over a predetermined distance. Several strength assessment procedures possess this characteristic. Most commonly associated with the term is a specific test developed to provide a relatively quick assessment of a subject's maximal lifting capacity using a modified weight-lifting device.(1,5) The classic psychophysical methodology of assessing maximum acceptable weights of lift is also considered an isoinertial technique under this definition.(6) While the definition provided by Kroemer(1) and Kroemer et al.(4) has been most widely accepted in the literature, some have applied the term "isoinertial" to techniques that differ somewhat from the preceding definition, such as in a description of the Isotechnologies B-200 strength testing device.(7) Rather than lifting a constant mass the B-200 applies a constant force against which the subject performs an exertion. The isoinertial tests described here apply to situations in which the mass to be moved by a musculoskeletal effort is set to a constant. Is Isoinertial Testing Psychophysical or Is Psychophysical Testing Isoinertial? As various types of strength tests have evolved over the past few decades, some unfortunate developments in terminology have arisen to describe and classify different strength assessment procedures. This is particularly evident in sorting out various tests that have been labeled "isoinertial." One example was cited earlier. Another problem that has evolved is that the term "isoinertial strength" has two connotations. The first is the conceptual definition: isoinertial strength tests include any strength test in which a constant mass is handled. In practice, however, the term is often used to denote a specific strength test in which subjects' maximal lifting capacity is determined using a machine and a constant mass is lifted.(1,5) Partially as a result of this dual connotation, the literature contains references to both "isoinertial strength test" as a psychophysical variant(8) and the psychophysical method as an "isoinertial strength test" (4,9) To lay the framework for the next two chapters, the authors will briefly discuss some operational definitions of tests of isoinertial and psychophysical strength. In stating that the isoinertial strength test is a variant of the psychophysical method, Ayoub and Mital(8) refer to the specific strength test developed by Kroemer(1) and McDaniel et al.(5) Clearly, this isoinertial protocol has many similarities to the psychophysical method: both are dynamic; weight is adjusted in both; and both measure the load a subject is willing to endure under specified circumstances. However, while both deal with lifting and adjusting loads, there are significant differences between the psychophysical (isoinertial) technique and the Kroemer-McDaniel (isoinertial) protocol in their procedures and the use of the data collected in these tests. For our purposes, we designate the

Jan 1, 1998

By C. T. Anderson

In July 1947, the U. S. Bureau of Mines, in cooperation with the Air Materiel Command, started an investigation of zirconium alloys with the object of determining the suitability of such alloys for high-temperature applications. This report covers the preliminary study of about 25 zirconium-rich alloy systems with respect to preparation, fabrication, tensile properties, metallographic structures; constitution, and heat resistance. Obviously, each system could not be investigated thoroughly, and this publication can be regarded only as a first approach. The more promising individual alloy systems will be studied in greater detail and reported in subsequent publications. The study of zirconium alloys on such a scale has been made possible by the U.S. Bureau of Mines developments in the past 5 years On producing zirconium metal. This basic process is similar to that developed by Kroll for producing ductile titanium metal and consists essentially of reducing zirconium chloride by means of molten magnesium. The Northwest Electrodevelopment Laboratory at Albany, Oreg., has produced several thousand pounds of ductile metal in this manner and has a pilot plant producing over 300 pounds of metal per week. Alloys were prepared by melting Bureau of Mines zirconium and the best available grade of alloying element in graphite, with suitable provisions for preventing oxidation. The ingots were quartered longitudinally and sheath-swaged at 850° c. to 3/8-inch diameter rod. Two of those rods were send to Wright Field for room-temperature and 1,200° F. tensile properties. The remaining two sections were used for metallographic, hardness, heat-treatment, and heat-resistance studies. The salient features of this investigation are summarized in table 1.

Jan 1, 1950

By Oliver C. Ralston

The Nonmetals Division studies problems relating to the use of minerals, many of which are important to national defence for purposes other than the extraction of metals. In fact, virtually all of the work of the division has been diverted to investigations pertaining to better use of the Nation's natural nonmetallic is resources as weapons of defense. The experiment stations of the division are at Norris, Tenn.; Tuscaloosa, Ala.; Seattle, Wash.; and College Park, Md. Studies involving the application of electric power to the nonmetallic minerals are conducted at the Electrotechnical Laboratory at Norris, and investigations on mineral-dressing treatment are conducted mainly at the Southern Experiment Station at Tuscaloosa. The cleaning and preparation of coal are studied at both Tuscaloosa and the Northwest Experiment Station Lit Seattle (other projects relating to utilization of coal are conducted by the Coal Division of the Bureau of Mines). Problems covering the use of minerals and fundamental problems as to their properties are studied at College Park.

Jan 1, 1941

By W. R. Crane

Recent papers on support of roof and top rock in mines representing present practice in so far as it hits been described by engineers in all of the principal mining countries, cover a relatively aide range of topics. The papers abstracted herein include such subjects as the testing of materials of support, failure and movement of rock above workings, effect of excessive pressures on rock masses, axed the application in mines of timber, metal, concrete, packing, and filling support. It is not within the scope of this paper to present a logical and orderly discussion of the elements of support and their application to conditions influenced by the material worked or the method of mining. Only the essential facts of a paper appear in the abstracts, the idea being to give a fairly clear picture of the behavior of various types of support under brows conditions and to put into concise form important information concerning present practice, modifications of practice, and the trend toward new practice. With such valuable facts from others experience made readily available, it Is hoped that the engineer with particular and often trying problems may obtain suggestions that will be immediately helpful.

Jan 1, 1932

By W. E. Bruce, James Paone

Drillability or a measure of drilling performance has been based on ( 1 ) hardness and toughness of rocks , ( 2 ) power input to the drill compared with total volume of hole , and ( 3 ) penetration related to resistive forces of rock on the applied penetrative forces . An analysis of some representative previous work is made . Experimental drillability curves from AX- size diamond core bit performance in eight different rocks ranging from dense hard taconite to soft limestones are presented . Results show that in small bore diamond drilling , compressive strength and possibly other rock properties may be a useful parameter in predicting drilling rates .

Jan 1, 1963

By Elton L. Litchfield, Milton L. Weiss

Studies were made on the projectile impact sensitivity of explosives by subjecting explosive samples to the impact of metal projectiles fired from a 0.50- caliber gun . The projectiles , in the form of right cylinders , made plane surface to plane surface contact with the explosives . Pressures in the explosive were investigated with an expendable pressure transducer in some instances . The physical model of the projectile - explosive interaction describes , in principle , the duration of the peak shock pressure in terms of the projectile and explosive geometry and the steady- state penetration of the explosive . Of the explosives studied , liquid hydrogen- solid oxygen and liquid oxygen - solid or liquid hydrocarbon fuel were the most shock sensitive ( requiring an initiating shock of about 1.0 kb or 987 atmospheres pressure ) ; cast TNT was the least sensitive ( requiring an initiating shock of more than 110 kb pressure ) . Measurements of pressure in the explosive showed some moderate space resolution by the transducer and gave pressure distributions in agreement with expectations from the model of the shock processes . The appearance of the recovered projectiles and the calculated initiation shock pressures suggest that the solid explosives were initiated directly to high- order detonation , whereas the liquid explosives were probably initiated to low- order detonation-- with a subsequent , later transition to high- order detonation .

Jan 1, 1965

By Terrence J. Stobbe

The authors investigated the nature, cause and treatment of 234 back injuries which occurred in 156 different situations in underground coal mines. A detailed interview was conducted with each injured miner as 137 variables were explored to provide a complete picture of the injury scenario. The miners worked at 23 mines in six states. An important finding of the study was that sudden movement, which occurred in 527 of the injuries, is a more frequent factor than heavy lifting in causing hack injuries. Along with sudden movement, other major injury causing factors were equipment seat design, lifting, cable handling, and slips/trips. No significant differences were found between the injury scenarios associated with lost time and non-lost time injuries; thus, both sets of scenarios should he used in doe loping back injury control strategies. Medical treatment and rehabilitation varied in content and quality. Dialogue between the medical, rehabilitation and mining communities is needed to develop an effective treatment strategy. Back injury control related training was found to be inadequate in most mines. Mine specific training for physical stress recognition and potential sudden torte release should he added to the training currently given. Based on the information collected in this study, recommendations were made regarding equipment design, mechanical assists and procedures for material handling, training, etc., which, if implemented, will assist in reducing the frequency of back injuries in underground coal mining.

Jan 1, 1989

Unfortunate occurrences resulting in injuries, loss of life, and destruction of property by explosion, fire, and other mishaps during shaft sinking in the past few years have focused the attention of the Bureau of Mines on the need for safety standards for such operations. 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, 1957

By Maurice E. Bailey

The purpose of this study is to determine worker acceptance of modified mine equipment at various intervals during a twelve month period. A survey instrument was administered to the workers by two experienced miners in four interviews. All four interviews showed a significant positive response to all modifications, except the small size of the cab of the shuttle car; however, the small size produced significant negative responses with respect to comfort in each of the four interviews. Initially, (interviews one and two), there were significant negative responses with respect to manufacturer receptivity to operator suggestions and program management follow-through on operator suggestions; however, the third and fourth interviews showed no significant negative responses with respect to these items. Likewise, there were significant neutral responses in the first two interviews; however, the third and fourth interviews showed no significant neutral responses with respect to these items.

Jan 1, 1975

By William Y. Mo

This Information Circular provides a detailed background documentation of how the Bureau of Mines projects U.S. mineral demand to the year 2000. These statistical projections serve as a quantitative basis for contingency forecasting of the low, high, and probable U.S. demand for nonfuel minerals by end-use categories and are published in the Bureau of Mines Mineral Commodity Profiles and Mineral Farts and Problems series. Aluminum is used as an example in this study.

Jan 1, 1980

By C. K. Eilerts

Knowledge of the phase relations of the fluids that exist in the porous spaces of rocks constituting natural petroleum reservoirs and of the behavior of these fluids under various field conditions of operation is essential to the conservation of petroleum and natural gas and to their efficient recovery. The problem of determining whether these fluids axe in the liquid or gaseous state send of recognizing the transitions that may take place as the material in the reservoir is subjected to different conditions of pressure and temperature confronts many producers today, especially in certain fields. The subject has grown rapidly in importance since the discovery of and production from deeper reservoirs that have correspondingly higher pressures rind temperatures as compared with shallower

Jan 1, 1938

By J. M. Mutmansky, C. Lee

"This paper outlines some of the work associated with a research study into the relationship between the characteristics of coal mine dust and the incidence of coal workers' pneumoconiosis (CWP). The project involves study of the chemical, mineralogical, and morphological characteristics of the dust. Early stages of the study have dealt primarily with the size analysis and elemental composition of airborne dust in continuous miner sections. This paper outlines the procedures and findings of the elemental analysis portion of the study.Most of the previous elemental analyses of coal were made available in the quest for information on the combustibility of coal dust or on causal agents and prevalence of CWP. However, no extensive studies have been performed to date, primarily due to the limitations of the analytical methods. A review of the analytical methods for elemental characterization of coal and coal dust particles is presented. TI1e comparisons are made based on the sample mass required, the sample preparation required, the destructivity of the test, and the capability of providing an easy multi-element analysis. The reasons for selecting the proton-induced x-ray emission spectroscopy (PIXE) method are outlined.The PIXE method was applied to both the airborne coal mine dust and channel samples collected from seven continuous miner sections in six different mines. Channel samples of the coal, roof and floor were collected and analyzed. Airborne dust sampling was performed using multi-stage cascade impactors and permissible 2.0 I/min pumps. Sampler locations were fixed in the sections with respect to the continuous miner and roof bolter or with respect to the intake and return airways. Sampling times varied from 45 minutes to 6 hours, depending on the dust concentration.The statistical analysis of the resulting elemental data is presented. Of particular importance are the analyses of the variation of elemental composition with size and the variation in elemental composition over the working section. One interesting finding is outlined showing the multivariate statistical analysis of the trace elements and its implications in the identification of the dust sources. The paper concludes with an analysis of the ramifications of the elemental data to related medical studies."

Mar 1, 1989

[1.1. The provisions of this code are minimum provisions and are designed to minimize hazards to life and property in and about underground coal mines where electrical equipment and circuits installed used. They indicate the Steps necessary in the selection, installation, operation, inspection, and maintenance of electrical equipment and circuits to obtain proper safeguards in reducing electric shock, fire, explosion and other hazards. Surface as well as underground installations were considered in formulating the code and, unless otherwise stated, each provision applies equal to both underground and surface installations. This code does not apply to buildings and installations not directly connected with mining operations, nor does apply to strip-mining operations.]

Jan 1, 1952

By Abrasive Materials

Table 1.-Salient abrasive statistics in the United States [ ]

Jan 1, 1967

With a growing concern over mine fires, prevention and suppression are hot topics. NIOSH researchers Michael Trevits, Alex Smith and Edward Thimons discuss their research in the area. The leading causes of US mine fires include flame cutting and, welding operations, frictional heating and ignitions, electrical shorts, mobile equipment malfunctions and spontaneous combustion. From 1990 through 2007, there were 1601 reportable fires that occurred in the US mining industry -an average of 89 fires per year. The fact that mine fires are occurring with alarming regularity reinforces the importance of recognizing and eliminating the potential hazards. These statistics also show the need for improved control and suppression technology to ensure worker health and safety if a mine fire does occur.

Jan 1, 2008

By C. A. Cole

This work consists of research in cable fault location and the construction of four field-test units based on the research. Swept-frequency sounding of mine cables with RF signals has been the technique most thoroughly investigated. The swept-frequency technique is supplemented with a form of moving target indication (MTI) to provide a method for locating the position of a technician along a cable and relative to a suspected fault. Separate, more limited investigations involved high-voltage time domain reflectometry and acoustical probing of mine cables. Particular areas of research included microprocessor-based control of the swept-frequency system, a microprocessor-based fast Fourier trans-form for spectral analysis, RF synthesizers, transmit-receive switches, RF receivers, cable dispersion-compensation techniques, low-voltage multielement display systems, and techniques for injecting or recovering RF energy through cable walls in support of clamp-on fault locators.

Jan 1, 1982

The U.S. Bureau of Mines (USBM) was established in the public interest to conclude inquiries and scientific and technologic investigations on mining and the preparation, treatment, and utilization of mineral substances; to promote health and safety in the mineral industries; to conserve material resources and prevent their waste; to further economic development; to increaseee efficiency in the mining, metallurgical, quarrying, and other mineral industries; and to inquire into the economic conditions affecting those industries. The organic act of the Bureau, as amended by Congress and approved February 25, 1913, made it the province and duty of the U.S. Bureau of Mines to "disseminate information concerning these subjects in such manner as will best carry out the purposes of this Act." In accordance with this directive, USBM reports the findings of its research and investigations in its own series of publications and also in articles that appear in scientific, technical, and trade journals; in proceedings of conventions and seminars; in reference books; and in other non-USBM publications. The number of these reports, the wide range of subjects they cover, and the variety of mediums in which they appear make this kind of list both necessary and valuable. This edition describes reports and articles published during calendar years 1992 and 1993. It supplements the 50-year list of Bureau publications from July 1, 1910, to January 1, 19602; and these 5-year lists of publications and articles: from January 1, 1965, to December 31, 1969\ from January 1, 1970, to December 31,19745, from January 1, 1975, to December 31, 19796, from January 1, 1980, to December 31,19847, and from January 1, 1985, to December 31, 19898?.

Jan 1, 2007

By Chas. F. Jackson

The work of the Mining Division is divided among seven sections, each in charge of a supervising engineer, as follows: 1. Metal-mining methods section, the supervising engineer of which is also supervising engineer of the Southwest Experiment Station at Tucson, Ariz. 2. Metal-mining research section. 3. Nonmetal-mining section. 4. Coal-mining section. 5. Mine-ventilation section. 6. Mineral-industries survey section. 7. Electrical section. The names of the sections indicate broadly the fields covered by each, and in the following, pages the objectives and type of work of each section will be summarized briefly and their active problems listed. The work clone during the fiscal year 1937 will also be summarized.

Jan 1, 1937