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By Levent Ozdemir

A 6-ft. diameter laboratory tunnel, raise and shaft boring machine was designed and constructed to carry out research investigations to enhance the performance of mechanical rock excavation equipment. The machine is operated with a computer control system and features extensive instrumentation to monitor and record various test parameters, including tri-axial cutter forces, machine thrust, torque, rpm and penetration rate. An extensive laboratory testing Program has been conducted using this machine, demonstrating the feasibility of attaining high rates of penetration in various sedimentary geologies. Also, a large data base has been developed to serve as a basis for the improved design and performance of tunnel, raise and shaft boring equipment.

Jan 1, 1986

By Charles G. Maier

"INTRODUCTION The use of thermodynamic calculations to answer practical problems in metallurgy, especially those that are relatively difficult to test experimentally, is rapidly becoming a conventional method of procedure. Nevertheless, these methods cannot he applied effectively until the fundamental thermodynamic constants used for them have become available either by direct experiment or by recalculation of data already existing in more or less undigested form.In an attempt to collect such data far the compounds of lead and the antimony group the incentive has been to make a preliminary survey that will disclose the gaps or questionable phases of available information and to collect data that may be used to answer certain rather practical problems presented by operating metallurgists.This report comprises three sections; the first gives the basis of selection of the constants which may now be given or estimated, and the later sections discuss the application of the figures obtained to two of the more interesting problems.The reader will discover that many of the quantities involve critical study of a number of more or less discordant observations. Although certain data could be rejected on the basis of thermodynamic comparisons, it must not be overlooked that many of the figures are the results of rational estimates rather than exact experiment. The use of thermodynamic methods to control and partly authenticate such estimates is one of its most valuable characteristics for the practising metallurgist or chemist, who cannot check by direct experiment each property of the materials which he converts to usable form.Nevertheless, while it is definitely possible in certain instances that the final figure selected for the heat or free energy of a process or substance may be in error by as much as a few hundred to a few thousand calories per formula weight, questionable figures are usually revealed by the thermodynamic calculations made. When quantities of such degree of accuracy are, and they often must be, used for estimating an unknown reaction, the result often gives no more than the order of magnitude of the desired quantities. Yet even in these extreme cases the answer is far more reliable and valuable than an unordered guess or a conclusion based on incorrect data."

Dec 1, 1934

By C. R. Summers

In response to the Coal Mine Health and Safety Act of 1969, mandatory noise standards have been developed that specify time-noise limits of mine personnel exposure. Most affected by elevated noise levels is the pneumatic roof bolter operator, both in terms of levels near or in excess of 115 dbA and in terms of length of exposure. Therefore, the principal emphasis of this Bureau of Mines report is on pneumatic drill noise control. It is not the intent of this report to suggest any drill redesign; instead, methods are suggested to reduce the noise level by complementing existing machines. An integral muffler system and a separate muffler system were tested in an attempt to lower pneumatic drill noise levels. Pneumatic drills, when new, operate at about 115 dbA when drilling in sandstone. Using the drill muffler systems, it was possible to decrease the noise level of a 115-dbA stope drill to approximately 100 dbA.

Jan 1, 1974

By F. D. DeVaney

Metallurgists and coal-washing engineers have used heavy liquids for years in studying the characteristics of ores and coal. By such means true separations can be made between the various specific-gravity increments in the materials examined. To use of heavy liquids has permitted determination of the possible grades of tailings and concentrates by specific-gravity methods on any particular size, and therefore the size to which the ore must be crushed to free the valuable material. The simplicity of float-and-sink separation and the high degree of efficiency attained in the laboratory are factors that commend the method for commercial concentrations.

Jan 1, 1940

By F. D. DeVaney

Metallurgists and coal-washing engineers have used heavy liquids for years in studying the characteristics of ores and coal. By such means true separations can be made between the various specific-gravity increments in the materials examined. To use of heavy liquids has permitted determination of the possible grades of tailings and concentrates by specific-gravity methods on any particular size, and therefore the size to which the ore must be crushed to free the valuable material. The simplicity of float-and-sink separation and the high degree of efficiency attained in the laboratory are factors that commend the method for commercial concentrations.

Jan 1, 1940

By Bruce Rock

A continuous mining machine was redesigned for the installation of an integrated illumination system. The illumination system was designed by first calculating the theoretical number of luminaires required to meet the Federal Illumination Standards. Luminaires initially were placed using isointensity diagrams. A darkroom was used for "fine tuning" and demonstrating that the system met the illumination requirements. The luminaire mounts were installed on a machine underground. The performance of this illumination system was monitored in the working environment of an operating coal mine. Design changes were made as necessary during this evaluation period to improve the system.

Jan 1, 1979

By N. A. Pace

This is one of a series of papers being published by the Federal Bureau of Mines for the dissemination of information on methods and practices used in the mining and preparation of crushed stone for market requirements. Performance in terms of units of work or tons produced per machine and per operator man-hour are given whenever that information is available. Direct operating costs are useful for comparing different methods, and are, therefore, included if possible. In addition to the factual description of equipment and methods used, it is desirable to discuss the engineering reasons for the choices that have been made. This paper is particularly concerned with the opertions at the Columbia plant of Palmetto Quarries Co. of Columbia, S.C. The plant is about one-half mile east of the Congaree River and adjacent to the southwest corner of the city of Columbia. Rail access is by the Atlantic Coast Line Railroad, and by a spur strack of the Seaboard Airline Railroad.

Jan 1, 1962

By B. W. Gandrud

This report, consisting mostly of float-and-sink data and washability curves, has been prepared in connection with an exhaustive study of coal preparation in Alabama conducted, by the U, S. Bureau of Mines and the University of Alabama with the cooperation of the different coal operators On the basis of the float-and-sink data, an attempt has been made to determine approximately the extent of ash and sulphur reduction obtainable under given conditions on coal from the mines which were sampled, In the coal-producing districts of Alabama a great deaf of attention has been given in recent years to the problem of improving preparation methods so as to obtain from various coal beds the best possible grade of washed coal. This is especially so where the washed coal is used for the making of metallurgical coke in by-product plants or where there are possibilities of using the coal for this purpose. In the manufacture of metallurgical coke, the sulphur content of the coal is a very important consideration. It is quite often the determining factor as to whether or not a certain coal can be used for coke making. In the studies which form the basis for this report, all samples have been analyzed for sulphur in order to obtain information regarding the possibilities of sulphur elimination as well as ash reduction, and the samples on which reports are made were obtained from beds that are characterized by rather high percentages of sulphur. In connection with the present investigations of coal preparation in Alabama a standardized method of interpreting float-and-sink data has been used extensively for predicting the ash and sulphur reduction and yields obtainable in a commercial washing plant from various sizes of raw coal and from the raw coal as a whole after a certain degree of crushing. This method, which will be explained in subsequent chapters, was used in interpreting the data contained in this report. The samples used for these washability studies were obtained from the following mines in the Warrior field of Alabama: Beltona mine on the Jefferson bed; Dolomite and Mulga mines on the Pratt bed; Coal Valley No. 163 and Coal Valley No. 11 mines on the Corona bed; Cedar Cove mine on the Carter bed.

Jan 1, 1932

By B. W. Candrud

This report, consisting mostly of float-and-sink data and washability curves, has been prepared in connection with an exhaustive study of coal preparation in Alabama conducted by the U. S. Bureau of Mines and the University of Alabama with the cooperation of the different coal operators on the basis of the float-and-sink data, an attempt has been made to deter-mine approximately the extent of ash and sulphur reduction obtainable under given conditions on coal from the mines which were sampled. In the coal-producing districts of Alabama a great deal of attention has been given in recent years to the problem of improving preparation methods so as to obtain from various coal beds the best possible grade of washed coal. This is especially so where the washed coal is used for the making of metallurgical coke in by-product plants or where there are possibilities of using the coal for this purpose. In the manufacture of metallurgical coke, the sulphur content of the coal is a very important consideration. It is quite often the determining factor as to whether or not a certain coal can be used for coke making. In the studies which form the basis for this report, all samples have been analyzed for sulphur in order to obtain information regarding the possibilities of sulphur elimination as well as ash reduction, and the samples on which reports are made were obtained from beds that are characterized by rather high percentages of sulphur. In connection with the present investigations of coal preparation in Alabama a standardized method of interpreting float-and-sink data has been used extensively for predicting the ash and sulphur reduction and yields obtainable in a commercial washing plant from various sizes of raw coal and from the raw coal as a whole after a certain degree of crushing. This method, which will be explained in subsequent chapters, was used in interpreting the data contained in this report. The samples used for these washability studies were obtained from the following mines in the Warrior field of Alabama: Beltona mine on the Jefferson bed; Dolomite and Mulga mines on the Pratt bed; Coal Valley No. 16B and Coal Valley No. 11 mines on the Corona bed; Cedar Cove mine on the Carter bed.

Jan 1, 1932

By F. A. Rutledge

The W. E. Dunkle mine, sometimes called the Costello Creek coal mine, is 8 miles N. 20° W. of Colorado Station on the Alaska Railroad. The presence of coal in this area has been known since the district was extensively prospected for gold between 1911 and 1915. At that time, coal from this deposit was used by miners for blacksmithing. The increased demand for coal resulting from government defense projects in Alaska led to exploitation of this deposit in 1941. The inability of Alaska coal mines to supply the quantity of coal required by public and private consumers and by the armed forces in Alaska was responsible for establishment by the Army of the Coal Procurement Section of its Alaska Department. It proposed to investigate the deposits and to expedite production from the Alaskan coal fields. The Bureau of Mines closely cooperated in this program. The quality of the Dunkle coal and the favorable location of the deposit caused it to be one of the properties chosen for investigation under a joint Army-Bureau of Mines-Geological Survey program.

Jan 1, 1948

By Clarence Karr

THE BUREAU OF MINES is investigating methods for upgrading tar produced by the low-temperature carbonization of bituminous coal. This survey was undertaken to compile information needed for identifying the ether constituents of low-temperature tar. Physical properties are listed for 1,024 aromatic ethers. The compounds include cyclic and noncyclic, polyfunctional and monofunctional ethers with oxygen joined directly to either one or two aromatic rings. Alkyl groups up through butyl are included. The compounds are divided into 37 groups ranging in complexity from alkoxybenzenes to dibenzopyrans. Compounds containing aromatic ether groups are important constituents of the neutral oxygen components of low-temperature tar. For example, at Morgantown, W. Va., the Bureau of Mines has identified and determined the amounts of benzofuran, 2-, 3-, 5-, 6-, and 7 -methylbenzofuran, diphenyl ether, dibenzofuran, 2,3-dimethyldibenzofuran, and two other dimethyl-dibenzofurans in the neutral oil from a low-temperature bituminous coal tar (103, 104).3

Jan 1, 1962

By G. L. Oldright

The studies previously made on Smelting in the Lead Blast Furnace have dealt with the custom smelter of the International Smelting Co. at Tooele, Utah,4 and on the smelter of the Bunker Hill & Sullivan Mining & Smelting Co.5 at Kellogg, Idaho. The International plant may be considered representative of the traditional custom smelter. The lead smelter of the future seemingly will have to treat increasingly richer lead charges. This feature was then stressed in describing the Bunker Hill plant.

Jan 1, 1934

By Thomas C. Mowatt

Preliminary Bureau of Mines studies of mafic igneous rocks collected from the Rabbit Creek area, northwestern Alaska, indicated concentrations of platinum (412 to 1,406 ppb) and palladium (343 to 892 ppb) in five of eight samples analyzed. The samples represent boulders and cobbles of mafic/ultramafic rocks from this locality. They are not from outcrop. Petrologically, (on the hand specimen scale) the samples are crudely to well-layered and are troctolitic ± gabbroie in character, with primary igneous mafic minerals strongly altered. Small patches of interstitial sulfide minerals, including chalcopyrite, bornite, pyrrhotite, pyrite, and covellite are associated with these altered zones and elsewhere through the specimens. Copper values ranged from 0.1 to 0.3 pct in samples analyzed semiquantitatively; nickel, cobalt, and chromium contents are low. Chemical, mine alogic, and petrographic relationships suggest that the rocks of similar character outcropping in northwestern Alaska could also be considered as prospective for- concentrations or platinum, palladium, and copper.

Jan 1, 2011

By Clyde L. Holmberg, Paul Zinner

"INTRODUCTION In view of the large tonnage of low-grade iron ore and iron-bearing material known to exist at the western limits of the Gogebic range, the Bureau of Mines undertook an investigation of the area for the purpose of evaluating the iron-bearing formations as sources of iron for possible future utilization.After 6o years of exploration an, development on the Gogebic range, the area investigated by the Bureau represents the known western limit of direct-shipping ore mined from operations on the Gogebic range.An area about 2 miles in length between the villages of Pence and Iron Bolt in Iron County, Vic., was selected for investigation, and trenches wore excavated through the overburden and fully across the iron-bearing formation to obtain 108 bulk samples for beneficiation tests. Exhaustive tests involving gravity and flotation methods, magnetic separation, and magnetizing roasts followed by magnetic separation were conducted on the samples to determine the ammability of the individual formations and the entire iron-bearing zone to beneficiation.Empirical data on the character and mineral content of the formations arc tabulated herein, as well as the results of the beneficiation tests."

Dec 1, 1947

By W. P. Huleatt, Jr. Traver, Jr. Hazen

"Vanadium and uranium occur widely distributed throughout western Colorado and eastern Utah, and a few deposits have been found in northeastern Arizona and northwestern. New Mexico. The area in which it occurs includes approximately 10,000 square miles and is generally referred to as the vanadium region of Colorado and Utah.The majority of the deposits consist of replacement bodies and impregnations of rare minerals in the lower Morrison formation of Jurassic age. The ore bodies are flat, with irregular margins, and most of them conform to the stratification.The ""rim rock"" topography of the region includes many steep-walled canyons and plateaus, which afford an abundance of outcrops that have been responsible for most of the discoveries of mineralized areas. Delimitation of ore bodies within the areas is accomplished most effectively by core drilling from the surface.The deposits were discovered in 1899 and from 1911 to 1923 wore worked extensively for radioactive uranium ores, principally carnotite.The discovery and marketing of the richer and more cheaply mined pitch-blende ores of the Belgian Congo left the Colorado-Utah deposits without economic importance as sources of radium and uranium, and the region became inactive in 1923. After a period of comparative inactivity, the rising demand of the alloy-steel industry for vanadium renewed interest in the deposits, which were known to contain that metal. By 1938, vanadium production in the area had achieved respectable proportions, and new impetus was given to it by the United States’ entry into World War II in December 1941. In 1942, new treatment plants for vanadium ores were completed in Monticello, Utah, and Durango, Colo. In order to meet the requirements of these and other plants in the region, it became necessary to open new vanadium mines and prepare old onus for production.In an effort to stimulate mining, the Metals Reserve Company initiated a stock-piling program and appointed the united states Vanadium Corporation, to act as its purchasing agent.The extra production was expected to come largely from small, independent operators whose limited funds did not permit them to maintain development and exploratory programs. Study of conditions made it apparent that extensive exploration would be necessary to sustain production, and accordingly the Bureau of Mines initiated an exploratory drilling project on a cooperative basis with the Geological Survey. The principal objects of the work were to enlarge the known ore reserves of the area and, if possible, discover new ones. The results have been gratifying in both respects."

Sep 1, 1946

Geophysical Abstracts 1 - 86 were issued in mimeographed form by the Bureau of Mines; Abstracts 87 - 111 were published in bulletins of the Geological Survey; Abstracts 112 - 120 were issued in mimeographed form by the Bureau of Mines as Information Circulars 7256, 7257; 7267,`7273; 7285, 7292, 7303, 7310, and 7324. 1. GRAVITATIONAL METHODS 7933. Ansel, E. A Eine Untersuchung zum Problem der Isostasie (An Investigation Regarding the Problem of Isostasy). Gerlands Beitr. Geophys., Leipzig, vol. 59, 1942, pp. 16-26.

Jan 1, 1945

By V. R. Spironello

The Bureau of Mines is involved in research directed toward the utilization of municipal solid waste. One of the primary objectives is the recycling of the magnetic fraction of municipal solid waste (raw refuse). This is consistent with one of the Bureau's goals, which is to minimize the requirements for mineral commodities by maximizing metals recovery from secondary domestic resources, In this investigation, cupola trials were made using combinations of refuse scrap with shredded automobile scrap under basic and acid slag practices. Furnace operating information and the behavior of alloying and tramp elements was obtained. The research showed that it is possible to utilize up to 60 percent refuse scrap in the cupola under basic practice and 30 percent under acid practice, Aluminum in refuse scrap, present in bimetallic cans, increased the recoveries of silicon and manganese charged to the cupola. Increased use of refuse scrap provided iron of lower sulfur. The alumina resulting from oxidation increased the slag volume. The aluminum and tin contents of the iron increased with increasing levels of refuse scrap in the charge. Lead was not a problem with respect to contamination of the iron. In basic practice, operation of the cupola was satisfactory since all slags were adequately fluid. In acid practice, operation became troublesome above the 45-percent level. Under both practices, the cupola iron melting rate decreased. Particulates in scrubber water and stack condensate samples contained lead, zinc, and tin, and the dust load increased. The tensile and transverse strengths of the iron produced under both practices are reported.

Jan 1, 1980

By J. R. Thoenen

In Progress Rerort 1,4/ a number of facto were demonstrated and conclusions drawn from experimental tests and records made during commercial blasting operations at a number of quarries. For example, the tests showed (1) that vibrations received on outcrops were of comparatively

Jan 1, 1938

By J. M. Singer

In this Bureau of Mines study coal and rock dust beds were entrained by airblasts generated by gas explosions at the closed end of a 0.61-m-diameter explosion tunnel, 49.7 m long. The system was designed to simulate entrainment of mine dust deposits by accidental gas explosion at the coal face of nonintersecting mine passageways. Full-scale mine explosion trials confirmed many of the results of the explosion tunnel experiments and indicated several new features of dust entrainment. Dispersal of 20.3-cm-long stepped dust beds located 35 m from the closed end always began during the early portion of the ascending gradient of the first transient airflow (and pressure) wave, and was usually completed before the end of the first quarter-wave period. Bulk quantities of dust were entrained simultaneously by longitudinal regression from the leading edge of the dust bed and by surface lifting of the top layer. Instantaneous threshold air velocities for bulk quantities of coal and rock dust beds in separate, mixed, and layered configurations were in the same range (5 to 30 m/sec) as previously found under steady-state velocity conditions. Selective lifting of coal dust layers from rock dust occurred when the threshold dispersal velocity of coal dust but not of the underlying rock dust was exceeded.

Jan 1, 1976

By Les A. Beckett

The Bureau of Mines has developed MULSIM/BM, an improved computer program using the boundary-element approach for geomechanical analysis of mine plans in single or multiple coal seams. This Information Circular presents the improved features of the MULSIN/BM program. The four major improvements are the following: (1) Ability to specify up to 26 material property sets. (2) A new material model capability for gob and inserted materials such as packwalls or cribs. (3) Ability to model a large area with a grid of undivided blocks and to subdivide only a specified fine-mesh portion of these blocks into elements. (4) Specification of extraction ratios for the undivided blocks. In addition, an interactive graphics mesh generator program was written to accompany MULSIM/BM. A complete user's guide and program listings are included within the appendixes. The MULSIM/BM and mesh generator programs are available on tape from the National Technical Information Service.3

Jan 1, 1988