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By E. D. Calvert

The Bureau of Mines, in its effort to promote greater utilization of domestically abundant materials, conducted reasearch on an alternate mold material that has commercial potential for titanium investment casting. Using variations of the conventional lost wax molding process, investment shell molds were formed entirely of fused, calcia-stabilized Zr02 and a Zr02-forming binder. Optimization of binder/slurry properties', stucco grain size and dis¬tribution, and curing practices resulted in a structurally sound investment shell that was distortion free and thermally stable. Small titanium castings, weighing up to 10 pounds, were prepared in unheated molds by both static and centrifugal casting techniques. Microstruc¬tural examination of the castings revealed that mold fill and surface quality were enhanced by centrifugal casting, although good results also were obtained from the statically poured molds. Microstructural and electron microprobe examinations showed that excessive, brittle case formation could be avoided by curing the dried shell molds in air for at least 2 hours at 1,400° C. Increasing curing temperature and time above these levels yielded added bene¬fits. Molds fired in vacuum at 1,500° C for 4 hours yielded castings essen¬tially free of case formation. The tensile properties of as-cast test specimens (no surface conditioning performed) id the chemical composition of representative metal samples showed that castings produced were comparable to Grades C-1 and C-2 unalloyed titanium This indicated that no sifnificant degradation of metal properties resulted from mold/metal interaction.

Jan 1, 1981

By John T. Metcalf

The assembly procedures for nine different wire rope terminations used in the mining industry are presented in a format and manner to facilitate training and to provide points where inspection of the termination should be performed. The nine terminations addressed are: Flemish Loop with Steel Sleeve & Thimble, Flemish Loop with Steel Sleeve, Wedge Socket, Swaged Socket, Turn Back Loop with Sleeve & Thimble, Thimble Splice with Four Tucks, U-Bolt Clip & Thimble, Zinc Poured Socket, and Epoxy Resin Poured Socket. The manual was prepared to be used primarily for field type mining operations or training where high capacity machinery is quite limited. It is nut the intent of this manual to suggest that the procedures presented are those to be used by manufacturers or other commercial enterprizes. A different set of procedures may be more appropriate where ideal space and equipment resources are available. The assembly procedures were derived from standard industrial practice, manufacturer's recommendations, and the open literature on the subject. These same procedures were used to prapare test specimens for an extensive series of pull and axial fatigue tests. The results of these tests indicate that these procedures are satisfactory in all respects. This manual is to be used as part of a complete training program. Although a brief glossary is included, there has been no attempt to make this a primer on wire rope. The selection of wire rope termination hardware, like the selection of the wire rope, is a subject not covered by this manual. The reader is cautioned that there are various sources for such hardware and this selection must be done carefully.

Jan 1, 1978

By Arnold M. Lansche

[Selenium and tellurium are rare elements in the earth's crust. Their scarcity and primary dependence of supply on copper and lead output are in consonance with the relatively small quantities consumed at 1964 level. Production depending on output of copper and lead creates a supply situation- which would appear to militate against development of large-scale usage of these elements. However, supplies have adequately met. demand in the past decade and can be increased substantially if warranted by new uses for either selenium or tellurium Ores of copper and lead re the principal sources of selenium and tellurium. Byproducts from the smelting and refining of copper and lead concentrates are incorporated in refinery anode slimes from which selenium and tellurium metal are recovered.]

Jan 1, 1967

By G. S. Scott

In the course of tire investigation into the causes, behavior, and control of mine fires, which the Bureau of Mines is now conducting, come attention was given to the subject of spontaneous heating. It is self-evident that the temperature of a pile of broken coal will rise if the rate of generation of heat exceeds the rate of heat dissipation and will fall if the opposite is the cane. Factors that affect the rate of generation of heat are:

Jan 1, 1941

The design, specification, and performance evaluation of the Communications and Location portions of a Coal Mine Rescue and Survival System are described. The work was performed as part of a nine month effort to develop a mine rescue and survival system using existing technology and state -of-the -art hardware as recommended by the National Academy of Engineering. Three basic subsystems were developed, one for survival, one for communications/location and one for rescue. This report and related equipment manuals describe only the Communications/ Location Subsystem which was designed, fabricated, and tested by the Westinghouse Georesearch Laboratory in Boulder, Colorado. Two basic technologies were used. Electromagnetic signals propagating through-the-earth provide voice downlink and coded beacon up-link communications. Seismic methods were developed to provide means for locating trapped miners. Seismic signalling also provides a backup means for communications. Parallel development programs for the electromagnetic and seismic portions of the system were conducted. The resulting hardware and software have been partially tested in coal mines and under simulated emergency conditions in order to evaluate system performance. The results of these tests are discussed. Further testing is recommended in order to establish quantitative performance limitations tinder a variety of environmental conditions and to develop methods for improving system performance.

Jan 1, 1971

By G. S. Rice, H. O. Howarth, Greenwald. H. P.

"Electricity as a means of transmitting power was introduced in coal mines of the United States about 1891 for both haulage and coal cutting, only a few years after electrical haulage was first installed on street cars. At first, the hazards of electrical ignition ere not appreciated and the general use of open lights and black blasting powder made the possibility of electrical ignition of fire damp seem small by comparison.5 The possibility of igniting coal dust directly by electric sparks or arcs had not been considered.In the nine years prior to 1900, the progress of introducing electricity underground was slow, except that it was used for lighting shaft bottoms. Electricity had to contend with the more general use of compressed air for coal-cutting machines and, in mainline haulage, with the use of mule-teams and endless and tail-rope systems. During this period, great improvements were made in electrical apparatus, in surface installations as well as in mines. By 1900, therefore, the technique of applying electricity in mines had so far developed that it rapidly drove out the use of compressed air in coal mines because of the comparative ease of its installation and the marked economic advantages of its use over that of compressed air in practically all kinds of mining machines except percussion. rock drills.At this time, however, little thought was given to the hazard of indiscriminate use of electricity causing explosions and fires, and the possibility of electricity causing direct ignition of coal dust had not been considered. On December6, 1907, however, the Monongah, West Va. mine explosion occurred. This was the greatest mine disaster this country has over had, 361 men being killed. Although: there was much diversity of opinion, as to the origin of the explosion, many well-informed engineers concluded that the cause was ignition of coal dust do to wreckage of a runaway trip in a rope haulage entrance slope. This slope also served as a ventilating and it extended from the level of the coal bed to the surface. The runaway trip tore down electric cables and stirred up a cloud of dust when it was wrecked at the bottom of the slope. The dust was probably ignited by the electric arcing that occurred when the wires were knocked down. (Another but less probable source of ignition was the open flames of miners lamps.) From the foot of the slops the explosion appeared to have travelled into the mine, spreading as it went. If this ignition of coal dust was the origin of the explosion, it occurred on pure intake air entering directly from the surface."

Oct 1, 1930

By I. L. Nichols

The inplace cyanidation leaching of gold from placer deposits is a potential method for treating gravels too deeply buried and too low in gold content to be processed economically by conventional dredging methods. Laboratory experiments were made to evaluate those placer cyanidation factors adaptable to small-scale studies. The variables investigated included gold particle size and location in sand beds, cyanide solution flow rate, and cyanide solution strength as factors affecting gold solubility rates. The solution flow rate, in turn, was influenced by variables such as bed slope, solution head pressure, and sand size, and the effects of these factors were studied. Free gold, minus 150-mesh and finer in size, is rapidly dissolved by dilute cyanide solutions from mixtures of gold and silica sand prepared to simulate placer deposits. About 94 percent of minus 325-mesh free gold was extracted in 5 hours from silica sand mixtures, and 94 percent extraction of minus 150-mesh gold was obtained in 21 hours with 0.1 percent NaCN solutions. Moving solutions were almost twice as effective in leaching free gold from silica sand mixtures than stagnant solutions.

Jan 1, 1971

By T. N. Williamson

Most U.S. coal production is bituminous coal. Some 90% of current production comes from a geographical area enclosed in a circle with a 300 mile radius and its center at about Huntington, West Virginia. There are important underground coal production areas in the western parts of the United States as well. Most U.S. coal production comes from fairly level seams, many of which pitch rather uniformly only a few feet per mile. Usually there will be several overlying seams of varying thicknesses, separated by several tens of feet. Fig. 1. 1. Seams have minor local undulations but these? are small enough not to be a major consideration in a horizontal drilling research program.

Jan 1, 1970

By William R. Hardwick

Present information indicates that a copper deposit can be safely fractured with a nuclear explosive and the copper successfully recovered by the in-situ leaching method. The process is not yet at the stage where it can be presented t ) the mining industry as a technique proven in all its aspects, but it is a method with high success potential. Unknown factors must be evaluated by a full-scale test before the economics or the extent of the use of the method by the mining industry can be predicted. Preliminary calculations indicate that the cost of fracturing a copper deposit nuclear explosives may range from l.8 to 55.2 cents per ton or in some case: less than a cent per pound of recoverable copper. Copper may be recovered at less cost than by conventional methods. Deposits with 4 pounds of recoverable copper may be economic and production from a deposit may begin in less than half the time required for conventional methods.

Jan 1, 1967

By N. H. Darton

This report presents the results of an investigation begun by the Government in the summer of 1907, the investigation being started under the immediate supervision of Dr. J. A. Holmes and continued under him as director after it was transferred to the Bureau of Mines in 1910, the field studies being completed in the spring of 1912. The purpose of the investigation was to obtain information on the origin of the inflammable gases in coal and the conditions under which they occur. It was especially intended to ascertain whether there was any relation between the occurrence of gas and the structural or other geologic features of the coal beds. To this end many months were spent in mines and much time was devoted to the examination of mine maps, bore-hole records, and other data made available by the kindness of various coal companies. Two fields of work were selected-one in the northern anthracite basin of Pennsylvania, where the beds are considerably flexed, and the other in the southern part of the bituminous coal field of Illinois, where the beds lie nearly horizontal. In order to take advantage of results of previous investigations of the same general subject, an extended examination was made of reports of various investigators in Europe and America. A digest of the information obtained from these publications is included in the first part of this report, which constitutes an introduction to the discussion of the conditions governing the occurrence of inflammable gas in coal beds.

Jan 1, 1915

By D. T. Randall

Several years ago investigations were begun by the United States Government to determine the most efficient methods of utilizing the coals of the United States. These investigations, which were continued along several different lines, are now being carried on by the Bureau of Mines, in accordance with the provisions of the act creating this bureau . . It was because of the need for more complete information concerning the conditions under which coal could be economically burned in boiler furnaces without objectionable smoke that tests were made at the Government fuel-testing plants at St. Louis, Mo., and Norfolk, Va. In addition to this experimental work a number of commercial plants in the larger cities were inspected to ascertain what were the best methods then in use for abating smoke. The results of these investigations were reported in Bulletins 334 and 373 of the United States Geological Survey. Because of the continued demand for the information contained in these bulletins, the original editions of which are exhausted, they are reprinted by the Bureau of Mines. The text of this bulletin, particularly the information relating to smoke ordinances, was revised in the latter part of 1910 and the early part of 1911 by S. B. Flagg, engineer, who has charge of the steaming tests being conducted by this bureau.

Jan 1, 1912

By George S. Rice

[This paper gives the details of tests to determine the design of stoppings capable of withstanding a pressure, applied to either side, of 50 pounds per square inch,6 as required by section 104 (a) of the Operating Regulations to Govern Coal-Mining Methods on Leased Lands on the Public Domain, issued in 1921 and quoted oil page 3. The regulations stipulated that the design for such stoppings must lie approved by the United States Bureau of Standards. The engineers of that organization felt that knowledge of the strength of such structures with respect to the effect of explosion pressure in comparison with static pressure and the strength of the walls which furnish the abutments was insufficient to justify drafting specifications; therefore, tests were needed to give information upon which a rational system of design could be based. A study was then begun; and several series of tests, made by the United States Bureau of Mines and the United States Bureau of Standards in cooperation, grave information upon which are based the detailed specifications offered in a later section. Slabs representing concrete stoppings, with and without reinforcement, were tested at the Bureau of Standards in Washington D. C.; afterwards, full-scale stoppings were tested at the Bureau of Mines Experimental mine near Pittsburgh. It was assumed that in most coal mines the strength of the floor and roof could not be relied on, but dependence must be placed upon the strength of the coal ribs. The tests developed that the maximum strength of an unreinforced concrete stopping was obtained when it acted as a flat arch buttressed against the coil ribs; but its ultimate strength depended upon the resistance to movement offered by the coal strata against which its ends were restrained or buttressed.]

Jan 1, 1931

By G. W. Jones

In a previous report'/ results were given and a method outlined whereby from a knowledge of the composition of the natural gas and of the inflammability limits of the individual constituents composing the natural gas, the limits of inflammability of natural gas and air mixtures could be closely calculated. This method is based on the application of Le Chatelier's law as modified by Coward, Carpenter and Payman,5/ to apply to a mixture of any number of combustible gases. This law must not be used indiscriminately, because many exceptions have been found. For example, when ethylene, acetylene, hydrogen sulphide, or chlorinated hydrocarbons are present the law may not hold. For a discussion of the many exceptions which have been found, reference should be made to a report by Coward and Jones.6/

Jan 1, 1933

By Shelby Z. Palya

"INTRODUCTION The Bureau of Mines was established in the public interest to conduct inquiries and scientific and technologic investigations concerning mining and the preparation, treatment, and utilization of mining substances; to promote health and safety in the mineral industries; to conserve material resources and prevent their waste; to further economic development; to increase 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 Bureau to ""disseminate information concerning these subjects in such manner as will best carry out the purposes of this Act.""In accordance with this directive, the Bureau 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 Bureau publications. The number of these reports, the wide range of subjects they cover, and the variety of mediums in which they appear make the kind of list and index presented in this special publication both necessary and valuable. This issue describes reports and articles published during the period January 1, 1975, to December 31, 1979. It supplements the 50-year list of Bureau publications issued from July 1, 1910, to January 1, 1960; 2 the 50-year list of articles by Bureau authors published outside the Bureau from July 1, 1910, to January 1, 1960; 3 the 5-year lists of publicatioll3 and articles, from January 1, 1960, to December 31, 1964,4 from January 1, 1965, to December 31, 1969,5 and from January 1, 1970, to December 31, 1974; 6 and the annual lists of Bureau publications and articles from January 1 to December 31, 1975,7 from January 1 to December 31, 1976,8 from January 1 to December 31, 1977,9 and from January 1 to December 31, 1978.10"

Jan 1, 1980

By Alan H. Goode

Glass wool meeting requirements for commercial use was made from glassy fractions of urban solid wastes by the Bureau of Mines. This research was a part of the Bureau's program to develop building products and other usable materials from reclaimed urban waste materials. Mixes of molten glass were fiberized into glass wool during laboratory studies by impingement of a jet of compressed air on a stream of the molten glass. The principal test variable studied was composition of the melt; this was varied by adding dolomite and alumina to obtain molten glass with the handling characteristics required for producing final wool products of the desired composition and physical characteristics. When no charge is made for the waste glass and approximately $75 per ton can be obtained for the wool product, an interest rate of return on investment after taxes of about 12 percent can be obtained. If a charge of $5 per ton is required for the waste glass, a selling price of about $78 per ton would be necessary to obtain a l2-percent-interest rate of return on investment after taxes.

Jan 1, 1972

By Dana C. Reinke

A job analysis is a written list of the tasks associated with doing a particular job. In drilling, describing the steps associated with adding rod to the drill steel would be an example of a task associated with the job. How to hammer casing or fish a lost drill bit out of a hole would also be job tasks. Develop a written list of job tasks. Ask drillers in your company if the tasks listed are correct and accurately reflect how to perform the job. While each driller may do the job a little differently, some tried?and?true methods are required to perform certain tasks safely and correctly. You may find a separate analysis is needed for different drilling jobs (e.g., a residential well or a monitoring well). Also remember to include the tasks of both the helper and the driller.

Jan 1, 2005

Surface mining and reclamation of a southeastern Ohio site with sandstone-shale overburden resulted in (as compared to premining levels): 1) runoff volumes and peak rates that increased by a factor of from 2 to 10 during mining and after reclamation, 2) destruction of the "aquifer" perched on the underclay of the mined coal bed and gradual, but, as yet incomplete redevelopment of this aquifer after reclamation, 3) no immediate effect on another, lower perched "aquifer", 4) up to 100 times greater sediment concentrations in runoff. Results were influenced by increasing annual precipitation amounts through the period of record; 1978, 1979, and 1980 (postreclamation years) experienced precipitation amounts approaching or exceeding long-term normalcy for the area. Part of the reason that the site produced more runoff after reclamation than before mining is that the premine condition was one of an open, porous soil under woodland, while the postreclamation condition was one of a compacted, bulldozed soil. Sediment concentration results were influenced by failure of the postreclamation erosion control system and by a series of detention reservoirs above the stream monitoring station.

Jan 1, 1983

By J. A. HUFF, V. V. BAKER

This circular is intended to present in brief form the statutory provisions of Pennsylvania regarding mining operations, in force at the end of the 1931 session of the legislature. lo reference is made to general laws which affect mining only incidentally in common with other subjects, such as the workmens compensation law. The statements have been condensed as far as practicable, and provisions not deemed of general interest, such as matters dealing only with administrative details, have been omitted. This circular obviously is not written with such particularity as to be of great value to the legal profession, but it is hoped that it will be beneficial to the mining industry in giving this information in a relatively compact form. At the end of each paragraph the statute from which it is derived is cited to facilitate reference to the text of the law. It is planned to publish additional circulars from time to time dealing with the mining laws of other States. Any criticisms of the form of publica- tion followed herein, or suggestions aimed at the improvement of future circulars, will be welcomed.

Nov 1, 1932

By JeffreyS. Vipperman, Daniel R. Babich, EricR. Bauer

In response to the continuing problem of noise induced hearing loss NIHL among mine workers, the National Institute for Occupational Safety and Health NIOSH has conducted numerous noise surveys in coal preparation plants. The research, consisting of worker dose monitoring, task observations, and equipment noise profiling, was completed in eight separate preparation plants. Worker dose monitoring was conducted for three shifts in most cases. Workers experiencing higher than allowable doses were task-observed for one full shift to correlate dose to noise source(s). Finally, noise levels on all floors, and in lunchrooms and control rooms, were characterized. Results indicate that only workers who routinely spend a significant portion of their shift in the plants (away from the control rooms) are susceptible to overexposure from noise. Certain pieces of equipment (screens, centrifuges, sieve bends) are the loudest primary noise sources responsible for the worker noise exposures.

This report is the 24th in a series summarizing research on coal and related investigations3 by the Bureau of Mines. The coal programs of the Bureau of Mines include a wide range of theoretical and applied studies--such as fundamental studies of coal structure and properties, the development and evaluation of new mining techniques, and work toward more effective processing and utilization of coal. The scope of these programs is indicated, in topical outline, by the table of contents. These investigations are integrated into a broad but coordinated effort to develop information on coal that will benefit the coal mining industry and the coal consumer while promoting the wise conservation and utilization of our national coal resources. Any attempt to summarize in one volume the progress in all of the program areas indicated must necessarily be limited to a brief review of developments, without detailed reporting of the data. However, while the brief discussion in each section will present only the highlights of the Bureau's work during the year, details of many of the operations or investigations described here can be found in the publications cited throughout the text. Other work, reported here for the first time, will be covered in greater detail in later publications.

Jan 1, 1962