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By Rolland L. Blake

The Bureau of Mines investigated the mineralogy, tonnage, and beneficiating characteristics of oxidized (nonmagnetic) taconite iron resources of the Western Mesabi Range as part of its program to insure adequate future domestic mineral supplies. Magnetic taconite currently provides about 95 pct of Mesabi production, but the large tonnages of oxidized taconite between the magnetic deposits will be needed to help meet future domestic demand for iron ore. Three bulk samples that represent large tonnages from the Western Mesabi Range were selected to determine their mineral composition and liberation by light optical microscopy and to test their beneficiating response. This report describes the mineralogy and liberation characteristics of the three samples of the Biwabik Iron-Formation for 26.5 mi (42.7 kID) from Keewatin to Grand Rapids, MN. (Details of response to beneficia-tion were reported previously.) The samples represent mostly material from the Lower Cherty Member of the Biwabik-Iron Formation, although one sample included some Upper Cherty Member. Minerals of all three samples were quartz (chert), hematite, goethite, and minor to trace amounts of magnetite, iron carbonate, and iron silicates. It was concluded that the oxidized taconites of the Western Mesabi Range represent a subeconomic indicated resource that can be selectively mined and beneficiated as a future large source of iron feed for steelmaking.

Jan 1, 1983

By S. J. Aresco

The Bureau of Mines has been active in promoting the purchase of coal for Government use under specifications that define the requirements in terms of heating value of the coal, expressed in British thermal units, and the composition as shown by proximate analyses. To these, when required, are added the ash-softening temperature, the free-swelling index, and the Hardgrove grindability index. Under most of these specification contracts the bidders guarantee the quality of the coal, and that guaranteed by the successful bidder becomes the standard of his contract. The deliveries are sampled in accordance with instruction3 issued by the Bureau of Mines; the samples are analyzed in the Bureau laboratory to determine whether the coal is of the quality guaranteed by the contractor; if it is not, a price adjustment is made. Analyses of the delivered coal and tipple samples (samples collected at mine tipples as coal is being loaded into railroad cars or trucks) provide valuable data for use in evaluating future bids. In addition, the continuous sampling of coal as delivered is a check on the practical results obtained in burning the coal.

Jan 1, 1969

By G. M. Kintz

In safety work a study of past accidents is of value in determining means of reducing future accidents of the same character. This is particularly true with reference to coal-mine explosions. Data from publications of the United States Bureau of Mines and from published reports of the State inspector of coal mines of Colorado are presented in this circular in the belief that they will be of value to operators by indicating methods of preventing future coal-mine explosions. The tables included are complete only with regard to major disasters. The Bureau of Mines considers as a major disaster one in which five 'or more men are killed. However, this circular also includes a considerable number of minor disasters, Various explosions in the coal mines of Colorado from 1883 to 1932, inclusive, are listed with information available as to their probable cause, number of men killed and measures which, if they had been in use at that time, might have prevented them. John McNeil, first Colorado State coal-mine inspector, on page 43 of his first report for the period ended July 31, 1884, made the following recommendations for the prevention of explosions in the coal industry: True causes could be traced either to insufficient ventilation, carelessness and lack of rigid discipline in carrying on energetic ventilation and other precautions needed to be enforced in a mine giving off explosive gases. *** When any quantity of fine coal dust is observed in an entry, air course, or room it should be made damp and be removed from the mine, and thus beep every place as free from dust as possible. *** A system of bratticing close up to the face of each and every place in the mine from crosscut last made (whether gas should just then show its presence or not) which should not be more than 50 or 75 feet according to the nature of the mine.

Jan 1, 1933

By Douglas A. Crum

The Taylor's friction circle method for slope stability analysis can be extended to incorporate multiple circles defining the slip surface in a failure mechanism so that it is a workable method for bearing capacity calculations of foundations and rotational failures of retaining walls and similar structures. The U.S. Bureau of Mines has further extended the multiple-circle method to include friction in the material strength and to utilize computational schemes such that this method can be programmed with optimization capabilities rather than being used as a graphical or semigraphical method. Some examples are given that demonstrate ultimate bearing capacity calculations of embedded foundations with eccentric loads and nearby slopes.

Jan 1, 2010

By Kenneth R. Maser

This report describes a research and development program sponsored by the United State s Bureau of Mines. The purpose of the program was to develop reusable explosion-proof bulkheads for a cross-cut emergency shelter, and to study the implementation of such bulk-heads, and the resulting shelters, as part of an emergency escape plan in a normal coal mining environment. The first part of this report reveals a number of significant conclusions regarding the application of emergency shelters. A study of the cause s of, and the conditions prevailing during a mine emergency indicate s that ideal placement of the shelter s would be midway along developing entries, and at the inter section of butt and main entries. The proper spacing of shelters is based on the travel capability of trapped miners, which is in turn dependent on the height of coal. The life of a given emergency shelter, based on an analysis of the above information, will be anywhere from 6 months to 10 years. Consequently, some shelters are regarded as "temporary?, while others "permanent?.

Jan 1, 1975

By M. Carrales, C. J. Jirik, W. D. Dietzman

In view of the developments and recent interest in recovering heavy oil , this report was prepared to present general information on more than 2,000 heavy oil reservoirs in more than 1,500 fields in 26 states . Information given on each heavy - oil deposit includes the following items : Field and formation , location , average or range of depth , average API gravity of oil , average thickness of formation , areal extent of field , total productive wells drilled in field , discovery date of field , field status in 1963 , cumulative production to Jan. 1 , 1964 , and all known types of secondary - recovery operations initiated ( active and terminated ) in the reservoirs . The geographical location of heavy oil accumulations in the United States is shown by a map , and a brief discussion of 14 different areas is given in the text . As of Jan. 1 , 1964 , 75 percent of the heavy oil reservoirs in the United States had produced more than 10 billion barrels of oil and are estimated to contain over 90 billion barrels of oil in place . It is also estimated that if the deposits which have had little or no production history , such as the one in Missouri , were included , the total remaining heavy oil in place would be in excess of 150 billion barrels . To find economical ways of recovering this vast reserve of heavy oil , industry is developing technology in several types of thermal - recovery methods . Some of the general considerations and more suitable limitations in selecting a prospect to study for thermal - recovery techniques are : Lithology , depth , viscosity of reservoir fluids , gravity of oil , reservoir thickness , oil in place , and permeability and porosity .

Jan 1, 1965

By Mackenzie Burnett

An inducer-type pump, capable of injecting dry coal into a hydraulic transport pipeline has been developed and installed in a specially designed and fabricated slurry injector vehicle. The full scale prototype injector system can deliver up to 11 ton/min of coal into an 8-in pipeline t pressures up to 95 lb/in2. The Helical Inducer Injector operates on centrifugal principles with flow passing axially through helical pitched conical rotor. Water is delivered to the pump through an annular slot at the atmospheric pressure coal inlet. The spinning rotor maintains an air-core vortex of water which pressurizes the discharge housing. A screw feeds coal through the open inlet into this vortex. The inner radius of the vortex contracts as pressure is increased, giving a limiting maximum pressure which is proportional to the square of the rotor speed. Below this limit, flow rate, discharge pressure, und rotor speed re independent variables. The self-powered, 4 -in high slurry injector vehicle follows and receives ROM coal from a continuous miner, reduces the top size to 3-in, and delivers the sized coal to the injector feed screw for slurry formation and pumps it through a mobile hose attached to the vehicle's outby end.

Jan 1, 1983

By Albert L. Toenges, Louis A. Turnbull, EDWARD L. FISH, JOSEPH J. SHIELDS, James J. Dowd

The stripping of coal with mechanical. equipment has progressed since the introduction of the first steam-powered shovel for the retóval of overburden at a mine in Pittsburg, Kans., in 1877...From the smart steam-powered shovels with dippers of less than a cubic yard capacity, small digging radius, and shovels that required manual moving, the trend has been toward large-capacity machines. Steam as power has been replaced largely by electricity, gasoline, and Diesel fuel, and dipper capacity as great as 35 cubic yards has been attained. Shovels and drag lines are self-propelled and revolve through 360°. The cost of these large-capacity modern machines is great, and in order to assure the return of the investment during the life of the property the reserve of coal in the area to be mined must be large;" Many comparatively small areas of coal suitable for strip mining exist, but these areas probably could not be mined, profitably with this large equip- ment. Therefore, heavy equipment has not been used in small areas because of the high cost in place of this equipment, the time and Atpense required to transport the machines to the mine site, and the construction of power lines if the machines are electrical powered.. Scrapers and light excavating equipment ane mobile, and the investment cost is not high. These units have been used in sirring the coal in small areas. A study to determine the methods in, yogue, and economic considerations involved in the use of such equipment was undertaken, and the information obtained is discussed in this report.

Jan 1, 1947

By Lloyd Williams

1. The investigation shows that the Sewanee bed is the only bed of major importance in Marion County, 97 percent of the coal mined in the county having come from this bed. There are coal reserves in minor quantity in the Battle Creek bed, and production from this bed depends on a few small truck mines. The Richland bed, or Lower Sewanee, has been mined in the past, but no coal has been produced from it in late years. There are no production records of any other beds in the county, although same coal has been produced from them. 2. Known measured and indicated reserves in all beds, based on a minimum thickness of 14 inches and on 1,800 tons per acre-foot of coal in place, are estimated to be 61 million short tons as of January 1, 1953. Of this total, 55 million short tons is in beds 28 inches and more thick. Areas in each bed were omitted from the estimate where available data relative to the bed characteristics are too meager to permit making an estimate that conforms with the definitions of measured and indicated coal adopted for this study. Should future drilling or development prove reserves in these areas, such reserves should be added to the total estimated reserves.

Jan 1, 1955

By S. R. Zimmerley

[In the course of a flotation investi£ation, a siliceous gold ore was ground in a'ball mill to ':1inns 300-meeh. It wa. found that the small amotIDt of _Ius 300-mesh material had a gole.. assay approximately twice that of the oriGinal ore, &~d that this overs.ize nroduct also contained much abrac..ed iron. .,Joreove I the gold assay of the abraded iron t which was !1epnrated ma§metically', ~iVFl.£ eight ti;nes that of the are. These facts suggested that some r31aticnship ex?...,ted between the abnorma11y high gold content an the prese:1ce of brA-cit)" iron. It was decided, therefore, to investigate furt~er th~ Fl.Gsociation of the bold ~ith the iron abraded from the balls during sri~Qing ]

Jan 1, 1937

By Allen S. Smith

Analysis of the helium content of a natural gas presents more than the usual difficulties encountered in applying the thermal-conductivity method because of the relatively small amounts of this inert as present and the wide variation in the other constituents. However, the numerous advantages of this method and its adaptability to Continuously recording and control instruments make it worthy of consideration. A specific application of the method described yields quantitative results only when used with gas mixtures of known qualitative compositions which Vary within predetermined limits. Periodic analyses for the helium content of a producing gas well may be conveniently made by an absorption method, and a continuums analytical method is not necessary for this purpose. Natural gas containing 1.75 to 1.90 percent of helium produced from Government-owned wells is processed in the Amarillo (Texas) Helium Plant of the Bureau of lanes. The helium extracted in the plant is supplied to the Army and Navy, and the processed natural gas is sold to a commercial gas company. As complete recovery of the helium in the raw material is not economically practicable, the processed gas contains 0.1 to 0.3 percent of helium, depending upon conditions of operation. Production is checked against the helium removed from the gas, which before the installation of the thermal-conductivity apparatus was calculated from the analysis of a cumulative sample of the processed gas. As conditions of operation affect the residual helium content to a large extent, a composite sample was an uncertain index of the efficiency of the process.

Jan 1, 1934

By S. H. Lorain

This paper is one of a series on mining methods and costs being published by the U. S. Bureau of Mines. The operations of the Quartz Hill Mining Co., near Dewey, Mont., afford an interesting example of the cost of mining small bodies of direct shipping ore; they also illustrate the effect of the unavoidable periods of unusually high exploration and development costs in this type of mining upon the cost per ton of producing ore. The importance of skilled geological guidance and the necessity of avoiding unnecessary overhead and capital expense at small mines are shown. Operating conditions at Quartz Hill are typical of those in many other mining districts of southwestern Montana. It is believed that the costs presented here may be of value in the preliminary estimation of costs to be expected by conservative operators under similar conditions elsewhere. The information contained in this paper was obtained during a visit to the Quartz Hill mine in August 1936.

Jan 1, 1937

By H. M. Cooper, R. F. Abernethy

Determination of the fusibility of coal ash consists in melting a pyramid of the ash to fluid under prescribed conditions . The conditions of the test are specified by the American Society for Testing Materials4/ and must be adhered to strictly if comparable results are to be obtained . The Society formerly specified a particular type of furnace , but with improvements in design of both electric and gas furnaces , it was decided by the Society to specify only essential details of the test . The Chairman of Committee D - 5 , Coal and Coke , of the American Society for Testing Materials suggested that the Coal Analysis Section of the Bureau of Mines conduct a cooperative investigation on the effect of furnace type and atmosphere upon fusibility of coal ash . The Coal Analysis Section enlisted the aid of a number of laboratories using the more common furnaces to cooperate in the investigation . Four types of gas furnaces burning natural and manufactured gases and two types of electric furnaces with different methods of maintaining a reducing atmosphere were employed . The results from the survey are tabulated herein , and some comparisons are made . There were not enough data from any particular furnace and atmosphere to make a reliable statistical analysis . However , definite tendencies are evident , and attention is called to them by direct comparison. in tables .

Oct 1, 1943

By G. E. McElroy, A. S. Richardson

"Experiments in the determination of friction factors for fan-pipe installations were carried on in a Butte mine during the fall and winter of 1922-23, under a cooperative agreement between the Bureau of Mines and the Anaconda Ccpper Mining Co. The results have been summarized in a separate paper,*** and this report, which is one of several giving more detailed data, discusses the methods used and the application of the results to fan-pipe practice.The use of canvas and galvanized-iron pipe, 8 to 20 inches in diameter, with small fans, usually electrically driven blowers, is an important factor in the ventilation of metal mines and is increasing in coal mines and long tunnels. In the Matte district the standard installation is an electrically driven small blower fan and 8 to 16 inch canvas pipe.The application of available data on friction losses in sheet-metal pipe to mine installations was doubtful, and very little has been published on canvas pipe, except general statements that the friction looses are greater than in galvanized-iron pipe. Experiments by Weeks and others,**** who determined friction losses under laboratory conditions for a few typical materials used in mine equipment, supported the statements.In 1918, one of the authors (Richardson) conducted tests for the Anaconda Copper Mining Cc. on the friction losses in canvas-pipe systems and the beet type of centrifugal blower for use with such pipe lines. He obtained the average total resistance per unit of length in use, without reference to the variable conditions of the lines. The results were of great value in developing more efficient equipment for average service conditions, and indicated that average friction losses for the commercial canvas tubing then used by the company were equal to or lees than these given for galvanized-iron pipe. Later on, the particular canvas tested was discarded for a heavier and more service-material."

Oct 1, 1923

By T. S. Chen

A study was made by the Bureau of Mines of the temperature and thermal stress distributions in thin circular disks subjected to peripheral thermal shock at various rates of heat transfer. The theoretical analysis is based on one-dimensional radial heat flow by conduction in the disk, and on heat exchange by convection between the disk and its surroundings. Preliminary experimental data obtained from shock tests on thin circular disks of basalt, quartzite, and taconite show reasonably good agreement with theory. The case of constant properties and plane stress is treated. Solutions of the stress distribution are presented for both cooling and heating shocks. The elastic energy stored at fracture is examined, and on this basis an average stress theory is formulated. Physical properties vital to the studies include thermal conductivity, thermal diffusivity, tensile strength, Young's modulus, and linear coefficient of thermal expansion. This work is of importance in predicting the thermal shock responses of a rock body of finite size.

Jan 1, 1966

By F. A. Rutledge

The Batesville district in north central Arkansas is one of the important sources of manganese ore and ferruginous manganese ore in the United States, with a history of production dating back to 1849. From studies by the Federal Geological Survey, it was recognized that the district probably still contains substantial reserves of low-grade ore. It was natural, therefore, that the deposits in this area should be among the first investigated by the Bureau of Mines under the Strategic Materials Act of June 1939, by which the Bureau was authorized to explore domestic deposits of strategic minerals, at that time designated as those of antimony, chromium, manganese, mercury, nickel, tin, and tungsten. The field work of the Bureau of Mines in the Batesville district was done in two distinct phases. Under project 308, active from August 1940 to June 1941, carbonate-oxide ores were investigated at five separate areas in which 100 trenches, test pits, shafts, and edits aggregating 4,364 linear feet were excavated and 839 samples were taken and assayed. Under project 323, in progress from February 1941 to January 1942, wad deposits were explored at 10 separate areas by 408 prospect shafts, churn-drill holes, and bucket-drill holes aggregating 23,680 linear feet from which 285 samples were taken and assayed. Processes for beneficiating the wad ores were investigated at ore-testing laboratories of the Bureau of Mines.

Jan 1, 1952

By R. V. Ramani, R. L. Grayson, R. L. Frantz, V. A. Marple, W. R. Myers, K. L. Rubow, Mutmansky. J. M., T. J. Stobbe

"An investigation of protocols for research performed from 1953 to 1988 on pneumoconioses (with emphasis on diseases related to coal and silica) was conducted in the Generic Mineral Technology Center for Respirable Dust. In addition, interviews were conducted with prominent U.S. medical researchers, aerosol scientists and engineers in government, industry, and universities to determine dust sources, dust preparation methods, laboratory protocols, and determinant variables related to in vitro and in vivo research and assess the comparability of results.Since the original report on the protocol project, additional research regarding free radical existence in freshly produced dust particles and the shape and contamination of particles generated for research purposes has further heightened scientists' concerns. As indicated by current research, fresher dust particles and those with more angular shapes may have a different level of reactivity in biological systems than do older or more rounded particles. Therefore, research on dust preparation methods for biomedical studies was undertaken and will be outlined here.Results of protocol review and interviews are summarized. Research on size reduction methods and their particle characteristics plus some recommendations concerning dust preparation methods and reporting in biomedical publications are also presented. Recent evidence indicates that these recommendations may be of importance in comparing and interpreting research results."

Nov 1, 1995

By W. A. Jacob, E. W. Dean

The Pittsburgh petroleum laboratory of the Bureau of lines has recently developed an improved method for the determination of water in pctroleum emulsions. It has been described in detail in an article entitled "A convenient method for the determination of water in petroloum and other organic emulsions" by E. W. Dean and D. D. Stark (Jour. Ind., and Enc. Chem. Vol. 12, ſay, 1920, page 436). It is essentially a modification of the familiar procedure of "distillation with an iniscible solvent", the improvement consisting in the use of apparatus that is rºck more convenient than any previously employed. The method has been used with marked success in the Bureau's laboratories for a period of about a year and has also been tried with equal satisfaction by a number of other laboratories. It has been most extensively employed for determining the water content of heavy fuel oils but has been applied also to several other types of emulsions, including shale oils, tars derived from coal, greases, and mixtures of powdered coal, oil and water. The Bureau has received a number of requests for information regarding commercial sources for the apparatus used, and having been assured of the value of the method, has taken steps to render it available for general use. - The equipment is, with the exception of two items, made of parts that are obtainable from the ordinary stock of chemical supply houses. The two exceptions are (1) the so-called "distilling tube receiver" and (2) the electric heater. The former is an essential part of the equipment; the latter is a convenient ac cessory but it can if necessary be roplaced by a gas burner. Efforts on the part of the Bureau staff to ronder these two items of apparatus available for purchase from supply houses, or for production by the user are hero described.

Sep 1, 1920

The Bureau of Mines Minerals Information organization collects worldwide data on virtually every commercially important non fuel mineral commodity. These data form the base for tracking and assessing the health of the minerals sector of the U.S. economy. This data collection activity was instituted by the 47th Congress in an appropriations act of August 7, 1882 (22 Stat. 829), to place the collection of mineral statistics on an annual basis. The most recent authority for the Bureau of Mines Minerals Information activity is the National Materials and Minerals Policy, Research and Development Act of 1980 (Public Law 96-479, 96th Congress), which strengthens protection for proprietary data provided to the U.S. Department of the Interior by persons or firms engaged in any phase of mineral or mineral-material production or consumption.

Jan 1, 1984

By W. J. Wenger

THIRTY-FOUR analyses of crude oils from the fields of the Four Corners Area of Arizona, Colorado, New Mexico, and Utah are presented and compared. The samples, taken from formations in four geological time periods, have high gravity and low-sulfur, -nitrogen, and -asphalt content. Generally, the oils are paraffinic in the low-boiling fractions, with increasing naphthenicity in the higher-boiling fractions. Oils from Cretaceous formations resemble other Cretaceous oils in the Rocky Mountains, but oils from Permian and Pennsylvania formations are unlike other oils of these ages in the Rooky Mountains. The differences in the oils are minor and cannot be used to distinguish between fields or between producing formations. With minimum special processing, the oils should yield large amounts of good-quality motor fuels. INTRODUCTION The only place in the United States where four States have a common junction is known as the Four Corners Area. This area (fig. 1) includes the northeast corner of Arizona, the southwest corner of Colorado, the northwest corner of New Mexico, and the southeast corner of Utah. It includes three major geological basins: The Black Mesa, the San Juan, and the Paradox. Major oil developments have occurred in both the San Juan and Paradox basins, but no discovery of commercial importance has been made in the Black Mesa basin.

Jan 1, 1960