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By Henry Kreisinger, F. K. Ovrız

Some of the investigations conducted by the Bureau of Mines have for their object the collecting and disseminating of information regard- ing methods by which the fuels of the country may be most effi- ciently used. As the analysis of flue gases tends to develop better methods of firing, which in turn reduces waste of fuel, the Bureau of Mines in this bulletin presents for the benefit of those in charge of boiler plants and all other persons interested detailed information on methods of sampling and analyzing flue gases, and on the utilization of the analyses in promoting boiler-room economy. This bulletin is intended to be a companion to Technical Paper 80," and is written in plain and nontechnical language, as far as pos- sible, so that it may be readily understood by persons who have not had the advantage of a technical education. Whenever possible, illustrations of apparatus and methods of handling have been used rather than elaborate descriptions. The material presented in this report is arranged in two parts. The first part contains the description of the apparatus and the methods used in sampling and analyzing flue gases. The second part gives experimental results obtained with the different methods of sampling and collecting flue gas that are recommended in the first part of the report. Only simple apparatus and methods are considered, as they are accurate enough to show the large heat losses due to the use of too much air, and are also accurate enough to indicate any incomplete combustion losses of economic importance. Without doubt the loss due to large excess of air is the greatest one in the boiler room, and can usually be greatly reduced by making proper use of gas analysis. Before engineers in the isolated industrial plants can be induced to analyze for small traces of combustible gases, they must be first taught how to analyze for carbon dioxide (CO), and they must learn to appre- ciate the great possibilities of reducing loss from large excess of air. Furthermore, in the face of the great difficulty of obtaining a fair

Jan 1, 1915

By Robert M. Becker

This report (part 3 of a five-part series) presents computer programs for evaluating moments and moment relationships of the generalized probability distributions extended or developed in parts I and 2. The principal program is for evaluating the first three moments and moment relationships of the compound-multinomial distribution for finite as well as for infinite populations. This is the generalized distribution for sampling to some amount of items per sample. Another program is for evaluating the first four moments, the moments of the mean, and the moment relationships of the multinomial and generalized hypergeometric distributions. This is a general moment program in sampling to some number of items per sample or for sampling to some number of samples. This program will accept either ungrouped data, frequency data, or probability data.

Jan 1, 1965

By Ralph H. Whaite

The Bureau of Mines program for microfilming maps of abandoned mines in the Pennsylvania anthracite region is described. A catalog of the maps that have been microfilmed in the Eastern Middle anthracite field--the first area to be covered in the program--is presented. Additional catalogs will be published as significant mining areas are completed.

Jan 1, 1965

By J. P. Conway

The yielding-rock-bolt concept, as developed in South Africa, consists of a smooth-bore die or collar fitted to a standard rock bolt. Laboratory testing at the Bureau of Mines Spokane Mining Research Center under slow and fast strain rates showed that extrusion loads can be controlled by varying the configuration of the die bore and that theoretical analysis (using basically Sachs' theory of wire drawing) predicts extrusion loads of the different die-bore configurations. A derived equation, based on this research, can be used for designed die-thread combinations for any desired extrusion load. Dynamic loading resulted in slightly higher loads (15 percent) than static loading. The strain hardening effect, which increases yield and ultimate strength, was partly offset by adiabatic heating of the threads, which decreases strength.

Jan 1, 1975

By Jon C. Volkwein

The U.S. Bureau of Mines conducted a study to assess the impact of a directional water spray system on a unique single inlet dust scrubber on a low-profile mining machine. Tests were conducted in a full-scale model mine using a continuous mining machine. Tracer gas was introduced at the face and concentrations of the tracer gas were monitored at the face and in the return. Various parameters tested included mining position, depth of cut, brattice setback, and combinations of scrubber, and directional or symmetrical sprays. Results indicated that either water spray configuration improved the ventilation effectiveness of the scrubber by a factor of 2 to 3. Average face ventilation effectiveness (FVE) values for all testing of the scrubber and directional sprays were 0.95, versus 0.37 for a standard 20-ft blowing curtain without sprays. No FVE values were less than the standard 20-ft blowing results.

Jan 1, 1989

By Dean E. Bluman

The Bureau of Mines investigated the convective heat transfer coefficients for recirculated suspensions of 30-micron glass beads in inert gas. Coefficients for the suspensions were not significantly higher than coefficients for the pure gas. Reynolds numbers of the suspensions were 20,000 to 35,000; solids loadings ranged from 0.0 to 0.7 pound per pound of gas. Comparison of the results with published data showed the direction of heat flow to have no effect at the test conditions.

Jan 1, 1967

By Wilbur A. Haley

One of the purposes of the investigation was to determine and report on how coal augers are used to mine bituminous coal that is near outcrops and may not be mined otherwise by any other present-day method. Such increased overall recovery results in the conservation of coal resources. Other reasons for the investigation were to determine and report the production rates of such operations and the types of equipment used. Auger mining of coal as a means of coal recovery supplementary to strip mining has been introduced and developed since World War II. This type of coal mining has grown rapidly, and bituminous-coal production by auger mining has been estimated at 6,000,000 tons in 1955. Mines were selected for study to give reasonably representative information on auger mining in different types and thicknesses of coal beds in different geographic areas and on different types and sizes of equipment operated under various conditions. This report is based on field studies of 8 auger-miming operations in Pennsylvania, West Virginia, and Ohio and in 5 different coal beds. Operations were observed in active strip mines, in strip mines reopened for auger mining, and along benched coal-bed outcrops. At the time of this study, no augers were reported to be operating in underground mines. The diameters of holes drilled ranged from 26 to 52 inches, and the lengths of holes ranged up to 208 feet. At some operations auger holes often penetrated abandoned underground mine workings.

Jan 1, 1957

By W. L. Cornell

The Missouri lead ores are the only domestic sources of cobalt presently being mined and processed for other materials. They represent the best short-term solution for meeting up to 13 pct of the Nation's strategic and critical cobalt needs from domestic sources. Presently, the cobalt is lost as an impurity in the copper, lead, and zinc concentrates and in the mill tailings because the technology to recover it with minium impact on present production does not exist. This paper presents results of research, built upon earlier Bureau of Mines laboratory research, to enumerate the problems encountered in cobalt recovery from the copper concentrate under actual mill conditions; to present alternative solutions to these problems; and finally, to describe the best available technology for cobalt recovery within the imposed constraints. Mineralogical analyses showed the cobalt present as a distinct mineral phase, predominately siegenite, amenable to a physical separation method such as froth flotation. Flotation was chosen for recovery because of easy adaptation by the mills. Unit processes of grinding, conditioning, and flotation were studied individually and in concert, and a series of continuous tests were run based on the parameters developed to obtain engineering data for subsequent economic analysis. Overall cobalt grades of 3.00 wt pct at a recovery of 64.0 pct were achieved.

Jan 1, 1987

By James H. Cobbs

The purpose of this study is to investigate the application of boring equipment to the production of anthracite coal from steeply pitching beds. Both raise boring and augering equipment were considered. Previous studies (11) have indicated that boring equipment may have definite applications to the development of steeply pitching anthracite beds. This investigation was to carry forward previous work to determine the possible application of the two different types of equipment being considered. Previous conclusions have been substantiated by the results of this study.

Jan 1, 1975

By W. L. Falke

The Bureau of Mines has developed a system that permits the "soft" soldering of aluminum and aluminum alloys with standard tin-lead solders. The method employs application of a thin nickel-copper-alloy coating to the substrate, which enables the tin-lead solders to wet readily and spread over the areas to be joined. With conventional technology, aluminum and aluminum alloys are extremely difficult to solder because tenacious surface oxide films prevent wetting. With the Bureau-developed method, the aluminum substrate is mechanically or chemically cleaned to facilitate bonding to a minute layer of zinc that is subsequently applied with an electroless zincate solution. The nickel-copper-alloy (30 to 70 pct Ni) coating is then applied electrolytically over the zinc, using immersion cell or brush-coating techniques. Development of acetate electrolytes has permitted deposition of the proper alloy coatings. The coated areas can then be readily joined with conventional tin-lead solders and fluxes. The joints so formed are ductile, strong, and relatively corrosion resistant, and exhibit strengths equivalent to those formed on copper and brass when the same solders and fluxes are used. The method has also been employed to soft-solder magnesium alloys.

Jan 1, 1983

Provide a means for reliable in situ stress change measurements in soft, friable geologic materials under high stress. Background Effective mine design requires a knowledge of changes in rock stress generated by a mining operation. In situ stress measurement can provide a means of obtaining this knowledge from an active mine for the ultimate purpose of design verification and analysis. The Bureau of Mines has designed and tested a device for measuring changes in rock stress-the borehole platened flatjack (BPF). It has found application in investigating stress anomalies due to geologic structures, stress concentrations from multiple seam interaction, and stress abutments from pillar retreat and longwall mining.

Jan 1, 1990

By Elizabeth G. Baglin

Research was conducted by the Bureau of Mines to determine the feasibility of using electrokinetic densification to dewater Bayer process red mud, magnetic black mud prepared by pressure digestion of red mud in the presence of ferrous sulfate, and magnetic black mud formed by simu-lated Bayer digestion of Jamaican bauxite with added ferrous sulfate. Tests showed that the solids content of presettled muds could be increased from 25 pct to approximately 40 to 48 pct by gravity draining followed by electrodewatering for approximately 48 h. Electrodewatering may not be practical because of increased reagent and processing costs and because the muds must be thoroughly washed prior to electrodewatering to remove dissolved ions and decrease mud conductivities.

Jan 1, 1988

By Floyd G. Anderson

A study was made of the effectiveness of dust-control methods being employed in connection with continuous-mining operations. Airborne dust exposures of workmen and dust loadings of return air were determined for six types of continuous-mining machines. The conditions required for control of dust exposure are summarized and include ventilation of the working face by an exhaust system. Return-air dust loadings ranging up to 13 pounds per hour are reported.

Jan 1, 1963

By Robert H. Dickson

This paper describing the mining practices at the Verde Central mine at Jerome, Ariz., is one of a series being prepared by the United States Bureau of Mines on mining practices, methods and costs in various mining districts of the United States. ACKNOWLEDMENTS The costs contained in this paper were prepared by R. J, Huddleston, chief clerk, Verde Central Mines, Inc.

Jan 1, 1931

By Oliver Bowels

Many inquiries are received by the United States Bureau of Mines for the names of elementary books on geology, mineralogy, methods of identifying minerals, prospecting, and similar subjects. In response to this demand the following brief bibliography has been prepared. As many of the inquiries are received from those who have limited technical knowledge of the subjects involved, the bibliography includes the simpler texts which present the subjects in nontechnical language. Other texts contain glossaries which define the technical terms used. A short note following the title indicates the character of each book, the number of pages, and the price. Thus, elementary mineralogists or geologists, prospectors, mineral collectors, nature students, or travellers may select the texts that best suit their requirements and their capabilities. To supply the needs of more advanced students, quite a number of the standard texts used in schools and colleges are included in a second group. A short list of books on economic geology and mineralogy has also been added.

Jan 1, 1929

By John R. Reeves

The data presented in this paper form the chief part of a general survey of the oil-shale resources of Indiana. Other papers* have already been published which contain data an various aspects of this resource. In combination, these papers present data with reference to the following points; (1) distribution of the New Albany shale; (2) amount of shale available; (3) homogeneity and thickness of the formation; (4) amount and quality of the oil obtained from the shale; (5) nitrogen content of the shale; (6) extractibility of the shale and its amenity to breaking; (7) some economic factors bearing upon the utilization of the shale; and (3) other miscellaneous factors and data. In the future, technical work on other phases of the general problem is expected to be done with the object of making a complete survey of this resource which is of much potential importance to the state and nation.

Jan 1, 1923

By William H. King

The Mining Division of the Bureau of Mines has been making development and power-requirement studios for the Interior Department Missouri Basin Field. Committee. The studies by the Bureau of Mines have as their purpose, the summarizing of potential future power requirements in the mineral industry within the Missouri Basin, special emphasis being placed on possible expansion of these requirements through construction of new mining enterprises by private capital. In preparing a proposal for the production of phosphoric acid from phosphate rock near Lander, Wyo., it was found that the basic information on the physical and chemical characteristics of the phosphate beds to determine costs of mining and treatment was lacking.

Jan 1, 1949

Federal lands often contain extensive mineral resources and decisions affecting access to those lands are made with knowledge of the possible minerals-related consequences. Information is provided to the Bureau of Land Management (BLM) in this report for use in preparing environmental impact statements on the Western Mojave Management Area (WMMA) and the Desert Tortoise Priority Habitat (DTPH). To augment U.S. Bureau of Mines (USBM) efforts such as the Mineral Assessment of the Planned Foil Irwin Expansion, Modified Silurian Valley Alternative, San Bernardino County, California which is in progress, and the Economic Analysis of the Minerals Potential of the East Mojave National Scenic Area; California, the USBM studied mineral deposits and estimated the potential impacts of mining in a segment of the California desert; the 8.7-million-acre WMMA, an area which includes the 1.2-million-acre Desert Tortoise Priority Habitat (DTPH). In addition, this information is intended to assist administrators, legislators, and the concerned public in understanding the economic importance of mineral resources in the California desert, especially that portion designated as the WMMA. See figure 1.

Jan 1, 1993

By D. E. Welcome, T. W. McDowell, R. G. Dong, S. F. Wiker

Workers using vibrating hand tools have the potential for developing health problems associated with repeated forceful actions and exposures to hand-transmitted vibration. Hand-arm vibration syndrome (HAVS) and other hand-arm system disorders have been associated with such exposures.1-2 To better assess health risks, comprehensive evaluations of these exposures must include quantitative assessments of hand-tool coupling forces; unfortunately, no standardized method for quantifying hand forces exists. Handle instrumentation may be ill-suited for some field environments. Psychophysical force-recall techniques may provide alternatives to handle instrumentation. A thorough understanding of the effects of vibration and other factors on force-recall accuracy and reliability is important before such methods are applied in risk assessments. Methods In this study, the effects of vibration and other factors on the accuracy of psychophysical force-recall were explored in two experiments. Twelve male subjects participated in the first experiment. The second experiment employed 20 participants (10 female, 10 male). In each experiment, participants applied specific grip and push forces to an instrumented handle mounted on a shaker system. Participants were exposed to sinusoidal vibration at frequencies that ranged from 0 Hz to 250 Hz. Three levels of applied force (low: grip = 15 N/push = 25 N, medium: grip = 30 N/push = 50 N, and high: grip = 45 N/push = 75 N ) and two levels of vibration magnitude (low: ANSI 4-8-hr limit and high: ANSI <0.5-hr limit)3 were examined. During the vibration exposure period, participants were provided with visual feedback while they attempted to “memorize” the applied grip and push forces. At the conclusion of the vibration exposure/force memorization period and a controlled rest period, the participants tried to duplicate the grip and push forces on a non-vibrating handle without the aid of visual feedback. The effects of different vibration frequencies, vibration magnitudes, and grip and push force levels were tested in a random order from trial to trial. Results Participants tended to overestimate grip and push forces. Depending on exposure conditions, error means ranged from 2 N to 10 N. The ANOVA revealed that force-recall errors for exposures between 31.5 Hz and 63 Hz were significantly higher than those at other vibration frequencies (p < 0.05). The frequency effect is depicted in Figure 1. Error means were greater when participants were exposed to the higher vibration magnitude (mean = 9.1 N, 95% CI = 8.2-10.1 N) when compared with the lower vibration magnitude (mean = 4.9 N, 95% CI = 3.9-5.8 N) (p < 0.05). The effect of vibration magnitude is shown in Figure 2. The average error for

Jan 6, 2006

By Fredrick L. Johnson

No mineral resources were delineated during our investigation of the Antelope Wilderness Study Area (WSA). Only a few claims have been located in the area and only four workings were found. There has been, however, considerable exploration and mining activity in and near the south end of the study area. The Morey mining district, just southeast of the WSA, produced silver, and lesser amounts of gold and lead, sporadically from the mid-1860&apos;s through the mid-1960&apos;s. Long Lac Mineral Exploration (Texas), Inc. is actively exploring a large block of claims for hot-spring type, low-grade, large-tonnage gold deposits. Their claim block extends into the study area. The WSA, located midway between Tonopah and Eureka, encompasses approximately 87,400 acres. It is underlain by Tertiary rhyolitic and latitic volcanic rocks and by Paleozoic sedimentary rocks. At least three areas in the Paleozoic rocks have many of the favorable criterion for hot-spring type gold deposits; they have been faulted, silicified, brecciated, and hydrothermally altered, and have anomalous concentrations of precious metals and pathfinder elements. With additional exploration in the south part of the Antelope WSA, gold resources may be discovered.

Jan 1, 1986