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By E. P. Barret

Differences in the reducibility of iron oxide materials have been recognized for a long time. Limonites are deoxidized more readily than hematites, and unaltered magnetites are the most difficult to deoxidize. Sinters are found between hematites and magnetites and vary considerably in reducibility, depending on the sintering practice followed and on the degree of fusion of the product. The increased activity in the beneficiation of taconite recently has made available a new blast-furnace raw material, namely, iron oxide pellets made from magnetic taconite concentrate. Many of the data in this paper apply to these pellets, or glomerules, as they were called when this method of agglomerating iron ores was first considered. To clarify the terms applied to iron oxide materials in this paper, the following definitions are given. Agglomeration is the general term applied to all methods of compacting or consolidating fine iron oxide materials. Sinter is the product from a Dwight-Lloyd or Greenawalt sintering machine. Pellets are formed by balling fine, moist oxide in a rotating drum at room temperature, followed by heating in a shaft furnace to a temperature below that of incipient fusion to develop a permanent bond. Nodules are formed by heating the iron oxide material to incipient fusion in a rotary kiln. Briquets are formed in a mold under pressure, with or without the addition of a binder, and burned to develop a permanent bond.

Jan 1, 1949

During the period 1979 thru 1982, Multi Mineral Corporation conducted a mining research program at the United States Department of the Interior's Bureau of Mines Oil Shale Mining Environmental Research Facility in the Central Piceance Creek Basin, Rio Blanco County, Colorado. The program consisted of mining, environmental and geotechnical research data and. the results are described in this report.

Jan 1, 1983

Collins Radio Company, through this contract with the Bureau of Mines, has conducted a System Study of Coal Mine Communi¬cations. The program was a three phase program to establish a data base, perform communication system analysis and optimi¬zation, and prepare equipment specifications to be included in this final report. At the start of establishing a data base both a knowledge of mine communication and coal mines in general was obtained. Communication system requirements and constraints were determined along with a survey of current and potential mine communication equipment. An investigation was completed concerning theoretical LF and VLF propagation characteristics, and UHF propagation tests were conducted in a working coal mine. Different mines were contacted and on-site surveys completed with respect to coal mine communication requirements.

Jan 1, 1973

By W. W. Adams

Rock dust, as a preventive or limiting factor in explosions of gas and coal dust in bituminous-coal mines, was used in larger quantities in 1939 than in any other year except 1937 since annual figures first became available in 1930, Reports from mining companies to the Bureau of Mines revealed that 144,430,000 pounds of rock dust was applied to underground nine workings in mines that produced 126,635,677 short tons of coal during the year. This quantity of rock dust applied averaged 1.14 pounds for each ton of coal produced. Rock dusted mines were the source of 39.7 percent of the total production of bituminous coal from underground mines; 33.2 percent of the total number of underground workers were employed at rock-dusted mines, and 35.8 percent of the total number of man-hours worked underground at all bituminous-coal mines in the United States during 19719 can be accredited to mines so treated. Rock dust was employed chiefly in the larger mines, which numbered only 431 out of 6,016 underground mines in operation in 1935, according to reports from mining companies. The mines in which rock dust was used had an average of 288 underground employees per mine, whereas mines in which rock dust was not used averaged only 62 underground employees per mine.

Jan 1, 1940

By R. G. Lett

Gaseous products resulting from rapid pyrolysis of coal and coal/inhibitor mixture's by a ruby laser and a flash-tube were monitored on-line by time-of-flight mass spectrometry. The distribution of stable gases from the coal is not Greatly influenced by the addition of small quantities of powdered flame inhibitors. Preliminary studies of the reaction of elementary radicals with coal and coal/inhibitor mixtures are described. The different types of experiments are discussed with regard to possible modification and application to studies of flame inhibitor action.

Jan 1, 1973

By David J. Kusler

This study is an appraisal of the feasibility of recovery and the possible chemical and physical uses of the limestone from the Greenbrier Formation in western West Virginia. Data on minability, occurrence, quality, and markets were obtained from published and unpublished sources and by a limited mail survey combined with personal contacts. The estimated costs of recovery by deep mining techniques are considerably higher than competitive surface and shallow subsurface operations. Compositional in formation available for this study was limited but indicated the suitability of the limestone for most physical uses and some chemical process uses in appraisal of the uses and demand reveals that immediate markets may be difficult to establish, but for some uses long-term prospects may be encouraging, especially if the quality of limestone would be suitable for lime manufacture or use as metallurgical fluxstone.

Jan 1, 1968

By Lisa A. McDonald

The environmental compliance process affects all aspects of hardrock-mining operations, from exploration through post-closure. The primary components of the environmental compliance process are requirements under the National Environmental Protection Act of 1969 (NEPA) and the permitting requirements associated with various other federal, state and local laws. This study considers the Greens Creek Mine and the development of two other projects (Alaska-Juneau & Kensington). These mines were used as the foundation for a case study of the impacts of the environmental compliance process on hardrock-mining activity in Southeast Alaska. The case study presents the institutional and legal requirements, followed by a discussion of the impact of this process on the production and timing of the three mines. The results of this preliminary study reveal some interesting findings, some expected and others unexpected, regarding the impact of the permitting process on the exploration, development and (proposed) operation of the three mining projects in the Juneau area. Determining the cost of compliance with these requirements is an important step in evaluating the appropriate course of action to protecting the environment while providing the necessary raw materials needed for society. This preliminary study highlights the initial starting point for such an analysis.

Jan 1, 1992

By P. M. Johnson

A design for a laser-powered optical interferometer, using a specimen whose thermal expansion is to be measured as part of the optical system, was conceived and applied in a prototype dilatometer. The object of thin work was the development of an absolute dilatometer capable of use at elevated temperature, particularly above 1,000° C. The prototype has been operated at temperatures exceeding 1,510° C. Results obtained with this device agree within 2.5 percent with the published data for the coefficient of expansion of columbium.

Jan 1, 1968

By F. A. Penning

This report describes the development of skip and guide desings for vertical shafts in deep vein mines. Skip and guide systems for bottom dump skips are identified as being used in current practice. Mine visits were made to obtain current information on the needs and problems of operating mines. Methods of structural and mechanical analysis of skip bodies and bails are outlined. A dynamic computer model was written to find the dynamic interaction between skips and guides for guides with geometric misalinements. A materials evaluation section identifies currentavailable and applicable materials that can be used effectively for new skip construction. Guide materials are also presented. Analysis includes the economies resulting from streamlined buntons and from low skip payload ratios. Selection of materials is based on strength, abra¬sion and corrosion resistance. Design requirements related to the shaft environment are presented. Consideration for the selection of guides and buntons is also given. Conceptual design includes the concept of cylindrical skips, center-seeking guide rollers, and asymmetric bail design to decrease dynamic interaction. An outline for field tests is presented. Future research areas are: testing, guide geometry measure¬ment, advanced suspension, dynamics, and structural configurations.

Jan 1, 1977

By B. R. Klahold

Each year hundreds of mineral specimens and numerous inquiries regarding tests and analyses of minerals and related inorganic substances are received by the Bureau of Mines. In response to this demand, in years past Information Circulars were published containing a list of laboratories. This paper is a revised version of Information Circular 7523, The listing has been changed from a regional basis to one of States arranged alphabetically and grouped by cities, again alphabetically, with Alaska and Canada listed at the end. All the services given at these laboratories are listed on one page for convenience and brevity. This list is compiled as a public service, and none of the laboratories listed herein are recommended over any other nor can the Bureau of Mines vouch for their results.

Jan 1, 1954

By Noel N. Moebs

The U.S. Bureau of Mines is conducting research on many topics relating to the mineral resources of the United States. This is done to ensure an adequate supply of minerals essential to a viable domestic industry and a sound economy. The United States is almost totally dependent on foreign supplies for a number of minerals such as chromium, niobium, tantalum, and manganese for which there is no available substitute, while many other minerals such as titanium are abundantly distributed throughout the earth but seldom occur in adequate concentrations or useful forms. This report describes an example of a small but high-grade occurrence of titanium are in Nelson County, VA. This occurrence could be exploited under favorable economic conditions with new mining technology such as borehole slurry mining. The report demonstrates that the dikes at titanium ore, a mixture of ilmenite and apatite locally termed nelsonite, can be detected and traced along strike using magnetometer traverses. This information will aid in the selection of appropriate slurry borehole mining test sites in the area.

Jan 1, 1993

By J. W. Miller

An investigation was begun by the Bureau of Mines in 1948 to determine the preparation characteristics of American coals. Results of the investigation were planned to be reported on a county basis and, from the data developed, to determine: (a) Which coals, either as mined or after beneficiation by conventional preparation, are suitable chemically under present standards for producing metallurgical coke. (b) Which coals require special and more intensive treatment in preparation than is now practiced. (c) Which coals cannot be considered potential sources of metallurgical coke, regardless of preparation. This report is one in a county series and describes the preparation characteristics of the coals of Logan County, W. Va. According to present-day standards for metallurgical coal, many believe that the sulfur content of the coal should not exceed 1.25 percent? Coal with more than this amount has been used for making metallurgical coke, especially when blended with coal containing less sulfur. In this series of reports 1.25 percent sulfur is used as a gage to determine whether or not a coal will be suited for metallurgical coke.

Jan 1, 1957

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 Lon A. Williams

This appendix contains drawing lists and drawings of components and assemblies designed for the prototype portable and machine mounted lighting systems per Tasks II & IV of Contract No. H0220065.

Jan 1, 1976

By David D. Rabb

A report on location, sampling, assays, mineral examination, amenability leach tests, and evaluation of certain mine dumps in Mohave County, Arizona. Extractions of greater than 30 percent of the gold and silver were achieved during simulated heap leaching of selected mine dump material. Consumption of reagents was relatively low and results suggest leaching of prepared heaps is technically viable and could be economically attractive.

Jan 1, 1980

By Paul C. Hyndman

Three properties in the Tuolumne River RARE II area, the Eagle Bluff Mine (lode) and the Indian Creek Bar and Bossy Bar Prospects (placer), have identified subeconomic gold resources (table 1). Nineteen other properties have potential for gold resources. Adjacent to the study area, five properties have identified mineral resources, and nine others have potential for resources. Properties having high-grade zones (shoots), but licking enough tonnage to be classified as resources, are listed in table 2. Gold, in lode and placer deposits, is the principal mineral commodity in the Toluene River study area. Ten properties within the RARE II boundary have gold-rich zones or shoots; they range in size from 12 to 2,500 tons and in average grade from 0.09 to 0.97 oz gold per ton.

Jan 1, 1983

By Thomas E. Doerfler

Information and data related to the occurrence of fatalities due to major disasters in metal/nonmetal underground mines were analyzed. Standard statistical methods were used to estimate the probability of occurrence of major disasters, and to examine the relationship of disasters to injury statistics published annually.

Jan 1, 1980

By W. D. Kaiser

Recent legislation and expected future legislation is aimed at reducing the dust levels developed in underground coal mines. Several techniques for reducing dust levels are being evaluated. One of these is the modification of cutting parameters such as feed rates, cutting speeds, and pick configurations in order to reduce the amount of dust generated. In order to evaluate the feasibility of modifying cutting parameters to reduce dust, the Bureau of Mines commissioned Battelle to construct a small scale mining machine which could be used for evaluating the effects of those changes in cutting parameters. Specific features of this machine were that it should be highly instrumented to measure various cutting parameters, should have a wide range of feed and speed controls, and it should be possible to vary the pick configurations and geometries on the machine. In addition, it was desired that this machine should have cutting capabilities which greatly exceed present coal mining practice and also that the unit should be small enough and portable enough that it could be taken into and out of operating coal mines with a minimum of interference with the normal coal mine operations. The first step in constructing a machine to meet these requirements was to determine the cutting forces and approximate sizes of components which would be required to cut at the speeds and feeds specified by the Bureau of Mines. Initial calculations using; published data on cutting forces indicated that cutting forces in the neighborhood of 5,000 lbs and power levels of approximately 30 horsepower would be adequate for the application. However, further data developed during the course of the project indicated that when low efficiency picks are used, cutting forces and powers can be two to three times as high as these initially estimated values. After several design iterations, a design was chosen in which the cutting head was driven by four hydraulic motors which were part of a hydrostatic transmission which, in turn,

Jan 1, 1973

By Lawrence K. Barker

Crude shale oil produced by underground retorting of Green River Formation oil shale was hydrogasified over a cobalt-molybdate-on-alumina catalyst at operating temperatures ranging from 800° to 1,300° F, pressures of 500, 1,000, and 1,500 psig, and a liquid hourly space velocity of 1.02 volumes of oil per volume of catalyst per hour (Vo/Vc/hr). At a temperature of 1,300° F and pressure of 1,500 psig, 94 weight-percent of the liquid feed was converted to gas containing 72 volume-percent methane. With two reactors in series at a temperature of 1,170° F in reactor 1 and 1,260° F in reactor 2 and a pressure of 1,500 psig, 97 weight-percent of the liquid feed was converted to gas with a methane content of 75 volume-percent. Liquefied petroleum gas (LPG) was hydrogasified at operating temperatures ranging from 500° to 1,400° F at a pressure of 500 psig over a cobalt-molybdate-on-alumina catalyst. Similar experiments were made with an empty tubular reactor. The data indicate that gasification reactions in the presence of a cobalt-molybdate catalyst change from predominantly a catalytic (carbonium ion) reaction to predominantly a thermal (free radical) reaction at temperatures greater than 1,100° F. The data also indicate that a reaction temperature of 1,350° F is necessary at the space velocities used in this investigation to make a synthetic natural gas (methane content of 90 volume-percent) from in situ crude shale oil.

Jan 1, 1975

By William N. Patterson

This report describes the design and testing of an improved quiet hard rock percussion drill. The improved drill incorporates a tappetless design with independent rotation in a hand held drill weighing 50 lbm. Laboratory and field testing in three mines were conducted. The testing showed improved drilling performance with no increase in measured noise levels over the fist design.

Jan 1, 1985