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By Gregory Krohn

This report investigates the effects of adding a layer of extra padding to the palm area of leather gloves typically worn by low seam coal miners. The first study showed that added glove padding provides more potential protection but does not affect manual dexterity. The second study, in a simulated low seam coal mine, showed no significant differences using padded and non-padded gloves in crawling, shoveling, timbering, and cart pushing task completion times. In general, subjects preferred the padded gloves although they expressed some complaints about awkardness and loss of sensitivity. Recommendations are given for the design of padded gloves that will provide comfort, protection, and maximum hand sensitivity for miners.

Jan 1, 1980

By Arnold C. Love

This report discusses current research by the U.S. Bureau of Mines on the effects of whole-body vibration (WBV) and shock on underground mobile equipment operators. The highlights of a comprehensive literature review of WBV, shock, and seating are presented. Factors discussed include health and physiological effects, comfort, performance, and fatigue. Vibration data were collected from shuttle cars and ramcars at several underground coal mines in Pennsylvania, Ohio, and Illinois. The data were formatted so that they could be used to drive the Bureau's motion platform, and to compare them with ANSI S3-1979, Guide for the Evaluation of Human Exposure to Whole-Body Vibration. Human subject testing in the Bureau's vibration research laboratory evaluated the effects of two different seat angles and of the presence or absence of vibration and of foam padding on heart rate, blood pressure, and subjective discomfort. Only vibration significantly increased heart rate and systolic and mean blood pressures. Vibration and a steel seat had a significant effect on subjective discomfort. The apparatus used for these tests and the experimental procedures are described in detail. Recommendations are made for additional research on the exposure of underground mining machine operators to WBV and shock.

Jan 1, 2010

By Oren C. Baptist

[Several new oilfields have been developed in northwestern Wyoming during the past 10 years, production is obtained from discontinuous, permeable sands enclosed within impermeable shales. The energy to drive the oil to producing wells in supplied by gas in solution in the oil. Most of the wells had high-initial potentials, but rates of oil production have steadily declined, indicating a dissipation of the driving energy and the possibility that large volumes of oil will remain unrecovered in the reservoirs. The studies reported in this paper were undertaken to develop laboratory data of the type most likely to be needed by persons studying the susceptibility of the Newcastle sand reservoir to secondary-recovery methods.]

Jan 1, 1957

By M. R. Yenchek

The U.S. Bureau of Mines designed and constructed sensitive and coordination-free ground-fault relays (GFR's) for use on mine power systems. First, a list of GFR attributes for mine ac utilization applications was compiled. These practical guidelines specified design, construction, transient immunity, reliability, and operating criteria. The time-current characteristics of the ac and dc units, subsequently fabricated, were designed to be below the human electrocution threshold. The significant and highly variable capacitance of high-voltage distribution cables was found to preclude the sensing of ground currents in the milliampere range. However, the coordination-free system developed for high-voltage distribution should enhance safety by significantly decreasing response time to ground faults. Implementation of the sensitive GFR technology in the mining industry has the potential to eliminate the majority of injuries and nearly all the deaths resulting from contact with energized components.

Jan 1, 1990

By R. S. Dean

"Applied Mineral Physics, by R. S. Dean.- This is an introduction to the seven papers that follow. It discusses the practical aspects of mineral physics and outlines the theo¬retical viewpoint underlying the investigations reported herein.Explosive Shattering as a Possible Economical Method of Ore Presentation By John Gross and C. E. Wood. - It is shown that explosion shattering by impact is favored by large charges and by low ratio of water to charge. For 400-gram charges of dolomite crushed through 48 mesh the steam costs are less than 5 cents per ton of dolomite obtained. This is within the range of present steam costs for ball-milling dolomite.Electrical Properties of Minersl Aggergates I. Natural and Artificial Aggregates Crystallized Lead Sulphide By R.S. Dean and John Koster - This paper deals with the electrical properties of natural and synthetic galena. It is shown that massive crystalline galena has a normal positive temperature coefficient of resistance, whereas fine-grained steel galena has a negative temperature coefficient, the curve R v. T being exponential in form. That steel galena behaves somewhat like a leaky condenser is indicated by ballistic and alternating-current bridge measurements. In determining the cause of the erratic results of alternating-current resistance measurements it was observed that the measured re¬sistance was a function of the current through the specimen. The direct-current resistance was found to be proportional to the square of a superimposed radio-frequency current and independent of the frequency.The influence of grain size or the amount of metallic interface on the voltage-current characteristics at various temperatures on synthetic galena pastilles was studied. It is proved that the volts v. amperes curves are linear for all sizes and temperatures, that they have an intercept which is apparently a linear function of the temperature, and that their slopes are exponential functions of the temperature and give rise to a negative temperature coefficient of resistance.Apparatus for determing the Magnetic Constants of Mineral Powders by V,H, Gottschalk,and C. W. Davis.- A modified isthmus permeameter having a spark-suppressed primary and a multiplier in the secondary circuit to regulate the effect of capsules functioning as a twin isthmus is used to obtain quantitative data and normal induction and hystersis curves from small amounts of powdered material at fields surpassing 3.000 oersteds. Data and curves are given to demonstrate the calibration of the apparatus and the reproducibility of its results. Applications and limitations of the apparatus are noted.Magnetization Curves for Magnetite Poeders by V. H. Gottschalk and F. S. Wartman.- This paper gives measurements on four lots of purified and analyzed magnetites in mixed fractions with especial reference to the variation of permeability with grain size and with dilution by an inert material."

Feb 1, 1935

By Jerry E. Olson

In 1988, at the request of the Bureau of Land Management, the U.S. Bureau of Mines studied additional areas, encompassing 11,303 acres, on the east and west sides of the 20,727-acre Badlands study area (Olson, 1987) in order to evaluate their identified mineral resources. The Badlands study area additions are located in Crook and Deschutes Counties, OR, about 10 and 18 miles east of Bend, OR. No mineral resources were identified. The additional areas studied are underlain by Tertiary-and Quaternary-age basalt flows which are largely covered by a veneer of sand and silt. No mines, prospects, mining claims or mineralized areas occur within or near the Badlands study area additions. Slab lava of marketable grade and quantity was not found in either area. None of the study area is of current interest for geothermal resources, but the eastern study area addition has been leased (1984) for oil and gas.

Jan 1, 1989

By Oliver Bowles

"The town of Monson in Piscutaquis County, Maine is the, center of an important site industry. Monson slate has a nation-wide reputation, particularly for electrical switch boards, and the deposits have been worked for the manufacture of such products for many years. Open-pit quarrying is the method most commonly employed in obtaining slate. Underground methods have been used in the Peaon Bottom district near Delta, Pennsylvania, but the quarries that were thus operated are now abandoned. Underground methods have been used more extensively in foreign countries, the most famous example being the slate mines at Angers in France, where an over-head stoping method has been employed successfully for many it is only under special conditions that underground methods can be successfully used. If the deposit is wide and relatively thin, or if the material is too unsound to constitute a safe roof, open-pit methods must be used, for slate is too low-priced a commodity to justify the heavy expense of any timbering methods. It is only where the deposit is relatively narrow, of great depth, and sufficiently sound to afford a strong roof that ordinary mining may be employed.The best slate beds in two of the three quarries operated at Monson are no worked by underground methods. The chief bed worked by the Portland Monson Slate Co. is 10 feet thick, stands vertical and strikes N. 63º F. The slaty cleavage is vertical and crosses the strike of the beds at an angle of 5 to 10°. The grain or second direction of splitting is vertical and perpendicular to the cleavage. In addition to the 10-foot bed, to 2-foot beds and one 5-foot bed are available but are not now utilized. In the Monson Maine Slate Co. quarry (the old Pond quarry),a greater number of beds available, but at present quarrying is confined to a single bed about 9 feet thick which dips 30º S.E. and strikes N. 47ºF. The slaty cleavage is vertical and strides N. 45º F., while the grain strikes N. 45-50º W. and is also vertical."

Nov 1, 1920

By Raja V. Ramani

The potential usefulness of reclaimed surface-mined land has received much attention recently. In an effort to develop a procedure for evaluating postmining land use potentials, specific mines in various regions of the U.S. were studied to determine the extent of current mined-land planning and to discover characteristics that are regional in nature. As part of this investigation, the Chinook Mine-West Field, located in western Indiana, has been studied. The Chinook Mine is presently operated by AMAX Coal Company and has been in continuous operation since 1928 under various ownership. The status of current reclamation and land use planning was reviewed. In addition, site planning principles were applied to the active mine area. This application included formation of a data base and development of postmining land use plan alternatives. Key factors affecting site potential realization for midwestern area mines have been identified along with suggestions for applying land use planning processes to mined-land planning.

Jan 1, 1983

By Charles L. Kimbell

On the basis of world production data alone, 1985 appears to have been a year in which the world's mineral industry took another step upward in its recovery from the very poor years of 1981, 1982, and early 1983. Despite a drop in the output of crude oil, which was the single most significant crude mineral product from the viewpoint of value, the estimated value of world crude mineral production advanced by 3.4% to about $1,054 billion constant 1983 dollars, with output increases logged for nearly two-thirds of the commodities and forms of commodities for which the U.S. Bureau of Mines calculates a total world output. However, the economic well-being of any industry or group of industries cannot be measured solely in terms of the volume and/or value of its production, and examination of statistics reflecting other aspects of mineral industry performance shows that 1985 was a less than ideal year in many respects. In the case of consumption of mineral commodities, although there were gains registered in diverse sectors such as iron and steel, aluminum, fertilizer materials, solid fuels, and gaseous fuels, there were also proportionally small but notable declines in use among the older major nonferrous metals (copper, lead, tin, and zinc) and in the all-important liquid fuels. In the case of international trade in mineral commodities, although comprehensive data for 1985 were not yet available, there were indications that the value may well have fallen below the estimated 1984 level of $632 billion, although the volume may have increased slightly. This, if true, would be chiefly the result of declining prices of mineral commodities, and indeed, price declines were noted for a number of significant materials in terms of current dollars, and even more would register declines if calculated on the basis of constant dollars, adjusting for inflation.

Jan 1, 1987

By R. T. Sorensen

Bench-scale and continuous testing were performed to adapt the anionic process for flotation of calcium activated silica to the fine-grained hematitic-goethitic jaspers from the Marquette range, Michigan. These ores typically contain about 35 percent Fe and require grinding to about 80 to 100 percent minus 400 mesh to insure an adequate liberation of gangue from the iron oxides. A method for removal of troublesome slime fractions without excessive iron loss, by first dispersing the quartz and then selectively flocculating the iron oxides, was evolved in the laboratory and successfully accommodated to pilot plant practice. The efficiency of the flotation process was improved with respect to both reagent usage and concentrate grade and recovery by using the selective flocculation-desliming technique as a pretreatment. The benefits of the combined desliming-flotation procedure were most evident in pilot plant processing. The best tests on two ores yielded recoveries of about 84 percent in concentrates containing 65.1 percent Fe and 4.8 percent SiO2 and 66.2 percent Fe and 3.9 percent SiO2, respectively. These results are in comparison to recoveries about 10 percent lower than the above to concentrates containing 63.9 percent Fe and 6.6 percent SiO2 in the one instance, and 63.6 percent Fe and 7.2 percent SiO2 in the other, obtained by flotation without the prior desliming treatment.

Jan 1, 1967

By Walter E. Lewis

A mothod of cutting St. Poter sandstono by streams of water under pressuro from nozzles and pumping the resulting, sand to the surface has roduced the cost of storm-sowor construction in the Minneapolis-St. Paul aroa. The hydraulic tunneling method, has boon in uso since 1934, and it is adaptable only to the lower part of tho St. Potor, sandstone, which lios within or just abovo the ground-wator levol. Tho upper part of the formation, immediately bolow tho Plattoville limestone, 18 comonted and camot bo mined by hydraulic mothods. The tunnel oporation observed in this instance is a main storm sowor starting at tho Mississippi Rivor below the 10th Avenuo SE bridge and will be drivon 6,000 foot at a grado of 1 foot por thousand undor the city of Minneapolis to Konnody and Arthur Stroots NE. A lateral storm sowor, which branchos from the main sovor at 8th Street SE, will oxtond from 10th Avonuo SE to 15th Avonuc SE. Tho tunnele are being drivon with the floor approximately at ground-wator lovol. All waters ontoring the main storm sower vill drain into the Mississippi Rivor. Tho main storm sewer cross soction is excavated to a roughly hox- agonal shapo 10 foot high by 10 foot wido at the contor. The upper half of the tunnol soction is solidly lined with either timber or stool. After all oxcavation is completed, the tunnel will be finished with a concrete circular lining 8 feet in inside diameter. The lateral storm sewer is excavated to a 5-1/2-foot by 7-1/2-foot section and will event- ually be finished with concrete to a modified horseshoe-shaped section 6 feet by 4 feet. Where the back or walls are considered unsafe during excavation, the upper half of the tunnel is lined solidly with timber. The equipment used by the Sower Division, City of Minneapolis, has been selected to meet a number of applications in storm-sewer work with diversified usage in mind. The sand pumps used on this job are rubber-lined, designed to work against a head of 100 foet. Either 4-inch or 6-inch diameter suction and discharge openings may be used. Other equipment, such as pipe, mine rail, flexible hoses, compressors, and general surface shop equipment, is drawn from a contral warohouse. It may be either new or used, depending on what is available at the warehouse. Much of the pipe and mine rail has been used for many years on several different tunnol jobs.

Jul 1, 1950

By E. Morrice

This report of the Federal Bureau of Mines presents a laboratory procedure, with the requisite equipment, for electrowinning ingot (liquid) cerium metal from a fused-fluoride bath, the metal purity being about 99.9 percent. Physicochemical studies, including bath properties and electrochemistry, are included, with a speculative model of the mechanisms involved. An historical review of the methods used for electrowinning misch metals and yttrim-group metals, as well as individual rare-earth metals, is presented. The electrolytic preparation of metal from fused salt and nonaqueous media is summarized, along with the unsuccessful attempts at depositing the metals from aqueous solutions.

Jan 1, 1961

By C. B. Barmore, B. W. Gandrud, B. M. Bird

"The Bradford mine of the Alabama By-Products Corporation is located in the Warrior coal field of Alabama, in the northern part of Jefferson County, about 25 miles north of Birmingham. The coal mined from the Black Creek bed at this point is not considered to be ideal for coke making by itself but because of its exceptionally low ash content is mixed with the higher-ash coking coals from other beds of the district to control the ash content of coking mixtures. Further reasons for using this coal only as a diluent of the higher-ash opals are that the thinness of the bed renders the production costs relatively high and the reserves are somewhat limited.This paper, which is the fourth of a series on the washability of Alabama coals, Like its predecessors dealing with the Mary Lee beds and the Clark bed,6 contains screen-sizing and float-and-sink tests of a representative sample of the raw coal, and flakiness tests showing the proportions of flaky particles in certain selected sizes. However, inasmuch as the float-and-sink tests of the coarse sizes showed excellent liberation of coal from impurities, crushing tests have not been considered necessary.The data on which this report is based have been obtained in connection with an exhaustive study of coal preparation in Alabama now being conducted by the U. S. Bureau of Mines and the University of Alabama with the cooperation of the different coal operators. As the work progresses other papers will follow containing further data on Alabama coals and giving results obtained in preparing these coals by various methods."

Apr 1, 1931

By L. P. Kleinmann

To control the formation of acid drainage at its source, the Bureau of Mines has investigated the role of iron-oxidizing bacteria in the oxidation of pyrite. In laboratory tests, it was determined that Thio-bacillus ferrooxidans could be controlled in coal refuse using anionic surfactants, with an associated decrease in acid production of about 75 pet. Based on these results, large-scale tests were conducted at an 8-acre active coal refuse area in northern West Virginia and an 11-acre inactive refuse pile in southern West Virginia. Acid production was decreased 60 to 95 pet for 4 to 5 months after application of 55 gal/ acre of 30-pct sodium lauryl sulfate solution. To date, effluent surfactant concentrations have been extremely low. Either a hydroseeder or a road-watering truck can be used to apply the surfactant. Since the surfactant solution must reach the pyritic material to be effective, sites that have been reclaimed are generally not amenable to these procedures. A simple laboratory test is described that provides an estimate of adsorption potential; this can be used to calculate a safe application rate.

Jan 1, 1983

By Robert W. Ageton

The Bureau of Mines investigated the in situ vertical component of the rock stress in the rib of the haulage drift on the 6100-level of the Star mine, Burke, Idaho, using the flatjack and borehole deformation methods. The estimate of the vertical component of stress about 2 feet into the rib at a station along the haulage drift on the 6100-level of the Star mine by the flatjack method is approximately 5,875 psi, whereas the borehole deformation procedure at this station yielded a value of 5,500 psi for the same depth into the rib. The test zone is approximately 5,625 feet below the surface.No attempt was made to extrapolate stress estimates beyond the depth of the flatjack installation.

Jan 1, 1967

By Michael S. Contratto, Dave Marshall, Tom Brodersen

The European Union (EU) completed a new directive 2002/44/EC1 called the Physical Agents Directive (PAD) that establishes action and limit values for hand-arm and whole body vibrations. The directive specifies that: “…workers shall not be exposed above the exposure ‘limit value’.” 1 and “…once the exposure action values … are exceeded, the employer shall establish and implement a programme of technical and/or organisational measures intended to reduce to a minimum exposure to mechanical vibration and the attendant risks…” 1 The PAD limit value is effective for new machines starting July 6, 2007 and for used machines by at least July 6, 2010. These requirements apply to the users of machines, but machine manufacturers will be challenged to provide machines and information to help the users comply with the directive. Caterpillar manufactures machines with the goal of enabling our customers to comply with all regulations dealing with health and safety. Caterpillar designs all of our machines to provide a safe, comfortable and productive work environment. This study was to determine if seat suspensions could provide a reduction in the vibration environment experienced by operators of Caterpillar mid sized (<50,000KG) Track Type Tractors Methods Seat manufacturers were asked to provide seat suspensions that provide improved isolation over and above current seat suspension. Each supplier was provided with ride profiles and was asked to demonstrate the vibration reduction on a shaker table. Two suppliers provided suspensions that were compared with the current seat suspension in a field study. Three full factorial experiments were conducted. The first experiment was to evaluate overall suspension performance for four operations. The second experiment was to determine the benefit of the adjustable vertical damper at three different levels and the third experiment was to determine the effect of the fore/aft and side/side isolators. Six operators were used for the study. Acceleration was measured at the seat base and at the operator seat pad. Both the transfer function and the ISO 2631 RMS ride values were used to determine the seat suspension’s effectiveness of isolating the operator from vibration. A structured questionnaire was used to determine the operators’ subjective assessment of the seat suspensions. Results There was significant operator-to-operator variability in the vertical direction (>35%), however there was little variability in the fore/aft and side/side direction based on seat base

Jan 6, 2006

By Albert L. Toenges, Theodore R. Jolley

"The development of Alaska depends on the existence of an adequate fuel supply in the Territory. The need to investigate coal deposits was recognized as early as 1911, when the first investigations were conducted in Alaska by engineers of the Bureau of Mines.Conditions existing in the Bering River and Matanuska coal fields, as found by Dr. Robert A. Holmes, former Director of the Bureau of Mines, are described by the Honorable W. L. Fisher, former Secretary of the Interior.4/Following Dr. Holmes' investigation, a party of Bureau of Mines engineers headed by R. Y. Williams visited the Bering River field in 1912 in cooperation with the Navy Department. A detailed examination was made of the Bering River field, and 855 tons of coal were mined from three prospects on Trout Creek. This bulk sample was delivered to the Navy for steaming and other tests. A description of the work of the field party and results of tests of the coal by the Navy Department and the Bureau of Mines has been published.During 1920 to 1922, the comparative steaming properties of Alaska bituminous coal, lignite, and wood were determined by the Bureau of Mines.6/In the early 1920's, the Bureau of Mines established a coal laboratory at Anchorage, where Alaska coals were analyzed. Subsequently, this laboratory was transferred to the Alaska Railroad and was used by the railroad for coal and other tests.Since 1910, the Bureau of Mines has made analyses of coal from Alaska, and the results of these analyses have been published.7/ The coal analyzed was obtained from mines, tipples, delivered lots, and face samples of coal deposits, and these samples were obtained in the field by engineers of the Bureau of Mines and geologists of the U. S. Geological Survey.Because of the shortage of petroleum and petroleum products in Alaska during the war, low-temperature carbonization assays of coals from the Broad Pass, Forty-Mile, Matanuska, and Nenana fields were made by the Bureau of Mines, and the results were published.Coal beds in the Matanuska field contain interbedded impurities in the form of shale, clay, and bone. The coal should be cleaned mechanically to obtain a satisfactory fuel. A coal-preparation study of bituminous coal from the Eska and Evan Jones mines was made by engineers of the Bureau of Mines, and the results were published.9/Coal production in Alaska is less than the requirements, and coal is imported to make up the deficiency. The cost of this imported coal is high. Greater production is necessary to supply coal for Army installations, industry, and homes. At present, there is only one bituminous coal mine (Evan Jones) in Alaska. The output of this mine is used at Fort Richardson, Anchorage, and by the Alaska Railroad. The economic life of this mine is limited (reported to be 3 years), and its closing, because of accidents or exhaustion, will cause great hardship to the inhabitants of Alaska. There is need to develop new, modern mines for the production of bituminous coal in the Matanuska field."

May 1, 1949

By Paul A. Pierce

In 1984, the Bureau of Mines evaluated an area previously identified as having "probable mineral resource potential" for copper, lead, zinc, gold, or silver within the Elkhorn Wilderness, about 5 miles west of Winston, MT. The purpose of this study was to determine whether the mineralized structures at nearby mines and prospects outside of the Wilderness extend into and contribute to the anomalous zone and, if so, to expand the domestic supply of strategic and critical mineral resources for future needs by identifying and quantifying resources on public lands. Fifty-eight soil samples, 23 rock samples, and 1 stream sediment sample were collected in the Staubach Creek area. Overall sample analyses suggest the anomalous zone in the Staubach Creek drainage is possibly associated with -.mall pyritiferous quartz veins. These veins or veinlets may be part of a system of northeasterly-trending structures prevalent in this art of the Wilderness. However, there is not sufficient evidence to prove that identified resources outside of the Wilderness extend into it in the Staubach Creek drainage, or that economic base- or precious-metal deposits are likely.

Jan 1, 1987

By Richard S. Fowkes

This Bureau of Mines report describes the Human Factors in Mining Search System (HFMSS), a computerized information retrieval system that provides relevant human factors information from journal articles, research reports, seminars, conferences, etc. in terms of 19 mining-related categories. It is the only existing data base that stresses all of the areas of human factors as applied to mining. Examples of these categories are biomechanics and work physiology, human error and human reliability, work design and task analysis, manual materials handling and back injuries, hand tools, organizational and management practices, psychological factors, and training. Although the emphasis is on literature dealing directly with mining, applicable material from other areas of research is included for those categories in which little research has been done in mining. Each record in HFMSS can be recalled by any field such as title, author, date, source, descriptive terms or key words, as well as by any words found in an abstract that describes the purpose, procedure, and results of the research. This report describes HFMSS fields and subject categories, the annotated bibliography, user&apos;s manual, and thesaurus of key words. Example printouts in both brief and full formats are included as an appendix.

Jan 1, 1990

By Richard F. Link, George S. Koch

Through the use of statistical methods, estimates of metal content and tonnage of an ore body made by using data from 18 diamond-drill holes are compared with actual values established with data from 1,829 drift samples. The reliability of the estimates made from the drill holes is assessed in several ways. The relationship of metal content (assay-width product) to grade is explained. It is concluded that useful estimates can be made from 18 drill holes provided that reasonable assumptions are made and certain risks accepted. The ore body investigated is the Don Tomas vein of the Frisco mine, San Francisco del Oro, Chihuahua, Mexico.

Jan 1, 1964