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By H. E. Powell

The magnetic susceptibilities of 57 minerals containing titanium, zirconium, vanadium, columbium, tantalum, chromium, molybdenum, and tungsten were determined. The source and petrographic analysis of each sample are given. Included are values for isomorphous series of minerals showing wide ranges of composition and for a few high-purity synthetic minerals.

Jan 1, 1968

By M. Howard Berliner

During the spring of 1944, the Bureau of Mines investigated the Crescent mine area near the village of Rewey, Iowa County, Wis., as part of a general investigation of the zinc-producing area of southwestern Wisconsin. The work was done when every effort was being made to increase the production of metals important to the Nation's war program. The Bureau of Mines completed 24 churn-drill holes in an area immediately to the west of a mineralized section which had been mined through shallow workings for lead and zinc more than 40 years earlier.

Jan 1, 1948

The panic bars (and associated linkages and electrical circuitry) that are defined in this document are a machine operator-actuated control for the emergency deenergization of the tram motors on self-propelled, electric and diesel face equipment; including haulage equipment such as shuttle cars. There are nine basic types of panic bars (and several variations) that are recommended in this document, but all of the panic bars are characteristically of the "fire door" type that is frequently encountered on outside exit doors of many public and some commercial buildings. It is also the intent of the following panic bar designs that, when emergency brakes are added to the face equipment machinery for which they arc required, that they be designed and hooked up so that actuation of the panic bar will result in automatic application of the emergency brakes (immediately following the deenergization of the tram motors). The following panic bar design requirements are a restatement of the proposed requirements defined in the Federal Register, requirements cited in "Guidelines for the Design and Installation of Devices for Deenergization of Self-Propelled Electric Face Equipment/Automatic Emergency Brakes" by G. E . Lester and J. D. Greenhalgh of MESA, and Bendix recommendations that were formulated as a result of discussions with personnel at the various machine manufacturers and underground coal mines that we surveyed, discussions with G. L. Judy (our consultant), etc:

Jan 1, 1974

By Launa Mallett, Charles Vaught, Michael J. Bmick

Since 1991 the Pittsburgh Research Center (PRC formerly part of the U. S. Bureau of Mines) has been tapping u valuable resource-researchers have recorded extensive interviews will, 30 individuals who are recognized as experts in the area of mine emergency response. These veterans related stories and observations from events experienced during as many as 47 years of response activities. Overall, the response veterans averaged 29 years of mine emergency response experience and 35 years mining experience. Individuals [ ] interviewed included representatives from mining companies, the UMWA and state and federal government agencies. This information was gathered so dial it could he provided to today's miners and to tomorrow's emergency response personnel. It is hoped the collective wisdom that has been obtained can be used to help train new responders and guide those decisions which mill have to be made on the scenes of future events. During interviews file emergency response experts were asked to discuss lessons they had learned through experience. The interviewers asked them to tell what they had learned that would cause them to handle similar situations differently and to tell about things they saw at past events shat the would warn others not to do in the future. In response the experts discussed a variety of things. Most of their responses, however, touched on some of the same topics including: preparedness, experience people on-site mine rescue teams, and decision making. A summary of their responses provides alt overview of [lie lessons learned on-site at tile largest mine disasters in the country.

By A. L. Engel

This report is a compilation of preliminary and, in some cases, more extensive concentration experiments by the Federal Bureau of Mines on low-and medium-grade fluorspar ores from three localities in Nevada and one in California. The work was done on samples obtained from Shoshone mine, Nye County, Valery mine, Pershing County, and the Broken Hills mine, Mineral County, all in Nevada, and Dirty Weather mine, Inyo County, Calif. These investigations were made to aid in the development of domestic fluorspar resources, in line with the Bureau's long-established program of conservation of mineral resources. The treatment methods employed in the experimental work described included simulated or "heavy-liquid" gravity concentration of coarse minerals and comparatively fine-grained minerals, and flotation concentration of finely-ground minerals. These methods were attempted in order to beneficiate the ores and produce concentrates which could be marketed readily, with as high a recovery rate as possible, while using simple treatment methods suitable for small-scale operation.

Jan 1, 1961

By L. H. Wullstein

Bureau of Mines research on methods for reclaiming land disturbed by the minerals sector of the economy has produced a specific procedure for effectively germinating seed of Indian ricegrass, a drought-tolerant plant valuable for reclaiming arid and semiarid sites. This report describes the procedure which consists of acid-treating the seed followed by temperature and light cycling treatments. Use of the procedure resulted in an average germination rate of 29 percent, ranging from 18 to 56 percent. Seed subjected to long cold treatment but with acid treatment yielded an average germination rate of 9.2 percent, ranging from 6.6 to 14.7 percent. Untreated seeds (controls) gave germination rates less than 0.1 percent.

Jan 1, 1979

By Kenneth L. Rubow, Virgil A. Marple

"INTRODUCTION Respirable dust is defined as the dust which penetrates to the alveolated regions of the lungs. Due to the size selective nature of the particle removal mechanisms in the nasal passages and lung airways, criteria defining respirable particles must be a function of the particle size. Three criteria defining respirable particle penetration are shown in Figure 1. These criteria have been defined by the British Medical Research Council (BMRC), the American Conference of Governmental Industrial Hygienists (ACGIH) and German TBF 50-11 (1).The quantity of respirable particles in an aerosol can be measured by use of two-stage samplers. The first stage consists of a particle preclassifier with penetration characteristics corresponding to one of the respirable penetration curves in Figure 1. The large nonrespirable dust particles are removed from the airstream in the preclassifier and the smaller respirable dust particles pass on to some device which can measure their concentration (the respirable dust concentration).Instrumentation for the measurement of respirable coal mine dust has been limited by the severe conditions existing within the coal mine. The conditions of particular importance are the methane atmosphere, high humidity, and the general non-laboratory type environment. The most severe of these conditions is the methane atmosphere since any electronic or electric powered instrumentation must be intrinsically safe to operate in such an atmosphere.In spite of the difficulty of sampling respirable dust within the mines, many instruments have been developed for in mine use. Although these instruments operate under a variety of principles they generally fall within two categories: personal samplers and area samplers.A personal sampler is worn by the mines while he is performing his duties in the mine. These devices are generally small, light weight and require little power so as not to interfere with the miner's ability to work."

Jan 1, 1988

By Sidney Katell

Several systems have been proposed for the production of synthetic crude oil from oil shale. An economic analysis of one proposed system is presented in this paper. An oil shale complex to produce 100,000 barrels per calendar day of semirefined crude oil will require a capital investment of $426,216,400. This investment includes mining, retorting, intermediate pipelining, and partial refining. A selling price of $3.74 per barrel of product will be necessary to maintain a discounted cash-flow rate of 12 percent.

Jan 1, 1971

By Bruce K. Cantrell, Stephen W. Stein, David Hassel, Harvey Patashnick

The Mine Safety and Health Administration. Department of Labor, requires coal mine operators to measure compliance with federal re¬spirable dust exposure standards periodically using approved gravi¬metric samplers. However, the gravimetric approach, with its inher¬ent delays, cannot provide dust concentration data quickly enough to allow on-site correction of inadequate dust control strategies or re¬moval of personnel from harmful environments. Furthermore, alleged tampering with dust samples collected to determine compliance with standards prompted the Secretary of Labor to appoint a special Respirable Dust Task Group to study options to improve monitoring and control of respirable coal mine dust. The Mine Safety and Health Administration's Task Group recommended that the U.S. Bureau of Mines develop a fixed-site monitor that would provide continuous information to the mine worker and mine operator regarding dust levels and the status of compliance with the applicable respirable dust standard. In response to the Mine Safety and Health Administration's request, the U.S. Bureau of Mines is investigating several sensor tech¬nologies for continuously monitoring respirable coal mine dust. One of these technologies is the Rupprecht and Patashnick Co. tapered element, oscillating microbalance. The bureau is in the process of investigating the suitability of using this sensor in the high humidity and vibration environment of underground coal mines. Laboratory tests have indicated that, with modification, the sensor can meet the humidity and vibration requirements for underground coal mine use. Currently, the bureau is developing

By Paul Biggs

This Bureau of Mines report provides information on 138 waterflood projects in Wyoming. Injection was in 25 producing zones and 65 fields. Specific data presented include field location, discovery and development, water supply and injection, oil and water production, estimates of oil in place, and oil recoveries by primary and secondary methods. The 138 projects studied will, if successful, recover about 800 million barrels of secondary oil. Almost all of the injection water is from deep water wells.

Jan 1, 1970

By Robert D. O'Brien

"INTRODUCTION The Miscellaneous Minerals Division of the War Production Board requested the Bureau of Mines to investigate the Gallatin corundum property as a possible source of corundum, which was in short supply due to the war. The Gallatin corundum property, also known as the ""Fuller mine"", the ""Montana Corundum mine"", and as the ""Old Qorundum mine"" was first examined by a Bureau of Mines engineer 2/ in July 1943. Bureau of Mines work on the property started October 11, 1943, was recessed May 5, 1944, and was resumed in October 1944 when the diamond-drilling program started. The project was completed February 7, 1945. The data obtained are given in this report.The Federal Geological Survey made a reconnaissance survey in the spring of 1943 and mapped the area the following autumn. The results of these surveys are contained in a memorandum report prepared in December 1943.ACKNOWLEDGMENTSIn its program of investigation of mineral deposits, the Bureau of Mines has as its primary objective the more effective utilization of our mineral resources to the end that they make the greatest possible contribution to national security and economy. It is the policy of the Bureau to publish the facts developed by each project as soon as practicable after its conclusion. The Mining Branch, Lowell B. Moon, chief, conducts preliminary examinations, performs the actual investigative work, and prepares the final report. The Metallurgical Branch, R. G. Knickerbocker, chief, analyzes samples and performs beneficiation tests."

Aug 1, 1947

By T. J. Ballard

The Conrad Hill mine vas first opened as a gold mine about 182 and has been operated at various times since then. The Bureau of Mines, as part of the strategic minerals program, mapped and sampled the accessible mine workings. The work failed to reveal appreciable copper values or evidence of additional ore deposits.

Jan 1, 1948

By John Ward Smith

An analytical method developed by the Bureau of Mines to determine dawsonite, nahcolite, and nondawsonite alumina (called excess alumina) extractable from Green River Formation oil shales is presented. The method requires water extraction of nahcolite followed by HCI-extraction of dawsonite and an unidentified mineral yielding excess alumina from the water-leached residue. Instrumental determination of sodium in the water extract and sodium and aluminum in the HCI extract measures the sample's content of the minerals. Detailed evaluation shows the method to be adequately specific, precise, and reproducible and free from uncorrectable interferences. The method's results define precisely the production of sodium carbonates and alumina possible from a sample of oil shale and the interval it represents. Shale-oil yields, nahcolite contents, and yields of extractable alumina determined on 83 samples representing an 821-foot section of dawsonite-nahcolite-bearing shale from .Colorado Corehole No.3, drilled in the north part of Colorado's Piceance Creek Basin, are presented. These samples resulted in nahcolite contents to 53.3 percent, oil yields to 48.3 gallons per ton, and alumina yields to 5.80 percent. Use of these data to evaluate the production potential of a section of the formation are suggested.

Jan 1, 1969

By Margaret M. Ragin

In a cooperative effort between the U.S. Bureau of Mines and the Florida Institute of Phosphate Research, with input from the phosphate industry, the conversion of phosphogypsum to sulfur has been investigated. The first step in the conversion scheme involves reduction of phosphogypsum to calcium sulfide. Effects of temperature, catalyst, reaction time, and type of reductant (carbon monoxide and coal) are discussed. It was determined that phosphogypsum could be reduced to calcium sulfide at 850° to 1,000° C using either coal or carbon monoxide as the reductant. The required temperature was lowered to 750° C using ferric oxide or magnetite as a catalyst for the reduction reaction. Results indicate that as the volatiles content of the coal is increased, reaction temperature may be decreased to obtain a given conversion, or if the reaction temperature is maintained constant, the conversion can be increased. Best results were 95- to 100-pct conversion using a high-volatile coal at 800° to 850° C. Addition of a catalyst increased calcium sulfide yield when low- or medium-volatile coals were used as reductants, but had little effect when high-volatile coals were used.

Jan 1, 1990

By J. Dean Warner

In 1984, as part of a project to evaluate Alaskan occurrences of certain critical and strategic minerals, the Bureau of Mines investigated a columbium-bearing regolith on upper Idaho Gulch, near Tofty, AK. The regolith is derived from weathering of a dolomitic marble and consists mostly of iron oxide minerals with accessory apatite, zircon, xenotime, rutile, monazite, and the columbium minerals aeschynite, columbite, and ilmenorutile. Two regolith lenses contain 340,000 lb of columbium resources at an average grade of 0.07 pct. Calculated composite concentrates from two regolith samples (approximately 200 lb each) contained 53 and 57 pct of the columbium at grades of 0.97 and 0.86 pct, respectively. In each case the grade could be improved to 1.1 pct Cb with a sacrifice of 9-pct recovery. The regolith's mineralogy, trace-element geochemistry, and similarity to descriptions of other columbium-enriched regoliths suggest that the underlying marble may be a carbonatite. The lack of associated alkalic igneous rocks and the stratiform nature of the regolith, however, may be interpreted as evidence for sedimentary origin of the marble. The marble and regolith are a lode source for some of the minerals in the Idaho Gulch placer deposit.

Jan 1, 1986

By J. G. Eisele

Solvent-extraction characteristics of dodecyl phosphoric acid (DDPA) were investigated to determine its potential as a fractional or selective extract-ant for individual elements in a rare-earth-yttrium mixture. The DDPA is an effective extractant for splitting rare-earth mixtures into light and heavy subgroups. Yttrium normally extracts with the heavy rare-earth elements but may be shifted toward an extraction sequence with the light rare-earth elements by increasing the pH. Elements in the light and heavy ends of the rare-earth series can be separated from middle-group rare-earth elements by using diethylenetriaminepentaacetic acid (DTPA) as an aqueous phase counter-extractant. Hydrogen-ion dependency of the distribution coefficients differs from that reported for similar systems at tracer-level concentration.

Jan 1, 1965

By Gerald L. Finfinger

The Bureau of Mines conducted an experimental degasification project in Island Creek Coal Co.'s Virginia Pocahontas No. S mine. Methane from the overlying Pocahontas No. 4 coalbed was entering mine workings in the Pocahontas No. 3 coalbed through fractures in the roof rock. Small-diameter (l-S/B-inch) holes were drilled into the overlying coalbed to reduce the gas pressure and intercept methane flows, which were piped to the surface through an underground 6-inch-diam steel pipeline. The total methane flow rate from the vertical holes averaged 150,000 ft3/day for the first month. Methane flows into the mine were reduced by 47 pet, thereby demonstrating the effectiveness of this form of degasification in reducing ventilation requirements and providing a safer working environment.

Jan 1, 1979

By Richard J. Mainiero, Marcia L. Harris

The New York State Department of Transportation recently commenced highway widening and drainage improvement projects in Clarence and Amherst, NY. Drainage improvements including the installation of storm sewer lines required excavation to a depth of 2.5 m (8.2 ft). In September 2002, NYSDOT stopped further blasting when 800 ppm CO was detected in the basement of a house near the blasting site. At the insistence of NYSDOT, the general contractor developed a new blast plan with the assistance of an environmental consultant. The plan provided for the installation of multi-gas monitors in buildings of special concern and/or with basements and residential type CO monitors in all other buildings within 100m (330 ft) of the blast. The multi-gas monitors would be remotely monitored. The plan provided action levels which would ensure public safety. The blast design was also modified to allow for better venting of CO. Blasts were limited to 20 ft lengths. The overburden was to be removed from the rock and blasting mats put in place to prevent flyrock. Approximately twenty feet of trench adjacent to the blast was left open to allow ground movement and gas release. The use of CO monitors was effective to alert occupants of a building to the presence of CO. The most effective appeared to be the residential type CO alarms with digital readouts. They were simple and easy to use and allowed the public to participate in the process. False alarms were repeatedly received with the more sophisticated instrumentation. Residential type CO monitors are preferable to warn people near blast sites. More sophisticated instrumentation should be avoided unless personnel are experienced in its use. A general overview of the blasting and monitoring is presented and discussed. The use and effectiveness of residential type CO monitors and multi-gas monitors are discussed.

By A. W. Fahrenwald

The logic leading to the development of the experiments in this paper already has been stated in Part I,3 but is briefly as follows: The results of the batch-grind experiments in which time of "grind" and fineness of finished product were the variables, strongly indicated (1) that batch grinding involving a single grind could not be operated under any condition to give maximum mill efficiency, (2) that the, sieve analysis of the feed charge in the mill materially affected the efficiency of the mill, and (3) that the percentage of finished product in the mill is a vital factor in ball-mill efficiency. A laboratory closed-circuit grind technic designed to simulate present closed-circuit grinding suggested itself, in which: a ball mill and a classifier constitute the grinding unit. The features of the closed-circuit grinding system are: (1) Short large diameter mills, (3) rapid flow of pulp through the mill, (3) continuous automatic removal of finished product from the system, and (4) high circulating loads. The high circulating load is a result if the short length of the Mill - that is, of the time the charge remains in the mill - and the small percentage of finished material produced during each circuit of the feed through the mill.

Jan 1, 1930

By Clarence O. Babcock

Model pillars of limestone, marble, sandstone, and granite having length to diameter ratios of 3:1, 2:1, 1:1, and 0.5:1 were broken in axial compression to determine whether lateral end constraint affected the breaking strength. Steel rings bonded to the ends of the model pillars with epoxy provided, during the loading cycle, a lateral end constraint of about 17 to 30 percent of the average axial stress. The effect of this constraint was to increase the breaking strength of the rock as compared to cylindrical pillars without constraint. The percentage increase in breaking strength varied with rock type and increased as the length to diameter ratio decreased. The maximum increase in breaking strength was 35 percent for marble pillars having a length to diameter ratio of 0.5:1. A theory was developed which relates the expected constraint to the physical properties of the ring and rock.

Jan 1, 1968