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By W. P. Yana, J. B. Littlefield

"INTRODUCTION AND OBJECT OF EXPERIMENTAn explosion in and rupture of a gas-tight switch box on an electric loader in a mine located near Pittsburgh indicated that the cause was an internally generated inflammable gas-air mixture. This led to the suspicion that moisture condensation or ""other unusual conditions might have caused a spark or are across the surface of the material and that the heat may have created a carbonized path across the synthetic plastic base which would then conduct a large current with the generation of considerable heat and thermal decomposition of the base materials base in the box which exploded gave every indication that this series of events had taken place, and accordingly it was desired to determine what explosive gases such a decomposition of these insulating materials would produce.ACKNOWNLEDGMENTSThe desirability of making this investigation was suggested to the authors by L. O. Ilsley, supervising engineer, electrical section, Bureau of Mines, to whom the occurrence of an explosion in a switch box had been reported. The writers also acknowledge with thanks the assistance of L. B. Berger, chief scientific aide, health laboratory section, Bureau of Mines, in checking the calculations in the tables. DESCRIPTION OF MATERIAL INVESTIGATEDThe ten materials used in the tests, identified by letters A to J inclusive, are described in a succeeding list of materials. All the materials except I had a phenolic odor, especially when freshly cut."

Dec 1, 1932

The State of Washington has a federal program that gives the Office of Surface Mining responsibility for assuring the reclamation of lands affected by coal mining. Most of Washington's coal-bearing regions lie west of the Cascade Mountains. The state's coal reserves are estimated at 1.4 billion tons, about 0.3 percent of the nation's total coal reserve. Steeply dipping. minable seams range from 2.5 to 25 feet in thickness. The occurrence of coal in Washington has been documented since the early days of its settlement; at one time, coal production played a significant role in the state's economy. During the late 1800s and early 1900s, coal was second only to lumber in Washington's industrial production. Coal production declined as other sources of energy were developed. By 1959, production was at 200,000 tons. Regulation of the coal mine operations in Washington is conducted by the Office of Surface Mining's Casper, Wyoming, Field Office and its local office in Olympia, Washington. All permit applications and abandoned mine land reclamation are completed by the OSM Western Support Center in Denver, Colorado. Inspections of mine and reclamation sites are conducted by OSM reclamation specialists located in Olympia.

Jan 1, 1992

By Richard C. Barth

Fourteen field plots were established at active coal mines in the Northern Great Plains. A wedge was cut into spoil and backfilled with soil; soil depth ranged from 0 to 152 cm over a linear distance of 15 m. Perennial grasses were planted in each plot, and production was measured from 1978 to 1981. Based on spoil traits and biomass response patterns, plots were grouped into four types. Spoil for Type I plots was near neutral, slightly saline, nonsodic, and clay loam in texture. Perennial grasses reached maximum production with approximately 50 cm of soil depth. Spoil for Type II plots was characterized as sodic and fine textured; soil-depth requirements averaged 83 cm for maximum production. Spoil for Type III plots was characterized as strongly acid, and production increased throughout the soil depth range tested. Spoil for Type IV plots was similar to soil in chemical and physical traits; there was no production response to soil depth. Soil depth requirements were also dependent upon precipitation and species. In general, soil-depth requirements decreased in dry years and with use of introduced species. An appendix contains data evaluations on an individual plot basis.

Jan 1, 1982

By Will H. Coghill

The scope of this paper is such that it was deemed advisable to group the contents into several main sections. They are: Section 1. Geography and Geology. Section II. Historical Review. (a) Mining and Smelting in Alabama. (b) Milling. (c) Summary of Milling Research. These two sections are primarily a bibliography and summary of the research on the Birmingham Red Mountain ores up to the middle 1040's. Section III. Status of the Birmingham Iron Industry. This sect ion points out the extent to which the findings of the iron-ore research have been applied on a commercial scale. Also, a very brief description of the dependent and allied industries is included. The value of the Birmingham iron ore is greatly enhanced by the proximity of coal and dolomite. Thus the coal and coke industry and the dolomite industry are closely allied with and to a large extent dependent upon the possibilities of economic utilization of the Red Mountain iron ores. Section IV. Beneficiation Investigations of the Red Mountain Iron Ores. This is a record of the most recent, hitherto unpublished work of the Southern Experiment Station of the Federal Bureau of Mines, Tuscaloosa, Ala., on the chemical and physical composition not only of the Big seam but of most of the iron-bearing rock strata of Red Mountain.

Jan 1, 1946

By F. E. Diebold

The wastewater-treatment system of the Anaconda Mining Co., at its Butte, MT., operation has been physically and chemically characterize modeled on a computer and investigated with respect to alternate systems for economic heavy metal recovery. The system involves lime addition to a mixture of acid underground copper sulfide mine water, acid effluent water from the iron induced precipitation of copper from acid leach solution and basic suspensions of solid effluent from a concentrator plant. Experimental chemical analysis and predictive computer calculations shows that the monosulfllte and disulfllte complexes of transition metals (Iron II being dominant) and alkaline earths are 40% of the total dissolved metal load of both acid streams. The suspended solids (30% by weight) in the basic concentrator slurries are dominated by quartz and pyrite and also contain kaolinite muscovite, biotite and undissolved lime. The mixture of these three streams result's in major reductions in concentrations of Al, Cu, Fe, Mg, Mn, Sir and Zn, and a pH >7 with calcium, sodium, potassium, and sulfate being the major dissolved ions. The treatment system has been simulated in the laboratory and accurately modeled on a computer. The computer program, an altered REDEQL-EPAK, is capable of accurately predicting the amount of lime required to reach a desired effluent water. Preliminary research has indicated the usefulness of electroprecipitation as a means of recovering the valuable metal load and providing an EPA acceptable effluent.

Jan 1, 1982

By Forrest T. Moyer

The National Safety Competition was inaugurated in 1925 by the Bureau of Mines, U.S. Department of the Interior, in cooperation with the Explosives Engineer. In the first nationwide contest, 210 mines and quarries were enrolled. In 1962, the thirty-eighth anniversary of the competition, 910 mines and quarries were enrolled. These participating plants were worked a total of 133,292,989 man-hours. Of the enrolled plants, 415 achieved injury-free operations for the year, the largest number of perfect safety records in the history of the contest.

Jan 1, 1964

By Michael J. Jorgensen, Anoop Polsani, Khurram S. Khan

Riveting operations in aircraft manufacturing involves the use of power tools for manually drilling holes for the rivets, power drills for the setting of the holes for the rivets, as well as rivet guns to drive and set the rivets. To close the rivet, the rivet is driven against a metallic bar commonly called a “bucking bar”. The bucking bars are typically held firmly to increase the quality of the riveting, as well as keep the bucking bar from “dancing” against the metal piece being riveted. Thus, employees in aircraft manufacturing involved in riveting are exposed to hand-arm vibration from several sources, and epidemiological evidence suggests that vibration-related musculoskeletal disorders are associated with long term exposure to riveting tasks in the aircraft manufacturing of aircraft.1,2 Recently, tungsten technology has been introduced into aircraft manufacturing for bucking bars, which are heavier than traditional steel bucking bars of the same size. Rivet guns with tungsten pistons instead of steel pistons have also recently been introduced with the objective of reducing vibration exposure to the riveter. The objective of this study was to assess vibration characteristics of steel and tungsten bucking bars and rivet guns to identify the combination that simultaneously reduced the combined exposure to both the “riveter” and “bucker”. Methods Vibration (10g tri-axial accelerometer, Biometrics S2-10G-MF Series 2) was measured from eight experienced employees using seven different rivet guns on size 6 rivets, with the same person bucking for all subjects. Vibration was also measured on two different bucking bars for these same eight subjects, with the same person driving the rivets using the various rivet guns. The rivet guns consisted of three E4 steel piston guns with different RPMs (Guns A-E4, B-E4, C-E4), an E4 vibration dampened rivet gun (Gun D-E4D), an E3 steel piston rivet gun (Gun E-E3) and an E3 and E4 tungsten piston rivet guns (Guns F-E3T and G-E4T). The bucking bars were made of 90% tungsten (1694g) and cold-rolled steel (843g), and were the same shape and size. A two-way repeated measures analysis of variance was performed on the vibration (mean frequency weighted resultant acceleration) on both the rivet gun side and the bucking bar side, and mean rankings were used to assess the vibration simultaneously for the rivet gun and bucking bars to investigate which combinations provided the lowest vibration exposure. Results Frequency weighted resultant acceleration was significantly lower on the E3 tungsten (F-E3T) rivet gun than the E4 steel piston (B-E4) and the E4 tungsten piston (G-E4T) rivet guns (Figure 1). When measuring vibration on the bucking bar, the E4 (A-E4) steel piston rivet gun resulted in lower vibration on the bucking bars than the E4 tungsten piston (G-E4T) and E4 vibration dampened (D-E4D) rivet guns (Figure 2). Additionally, use of tungsten bucking bars resulted in a 35% decrease in resultant frequency weighted acceleration than when using steel bucking bars.

Jan 6, 2006

By Frank L. Hess

"New England" and "granite" if not synonymous are at least associated terms. Where there are granites that are not deeply eroded there are usually pegmatites, the most erratic of rocks, and of them New England has a full portion. Many of the New England pegmatites contain the rare alkalis - lithium, rubidium, and cesium. however, the same in homogeneity of the earth's crust that has made the New England pegmatites unusual, in that so many of them contain the rare alkalis, has likewise made the distribution of the rare-alkali minerals sporadic even in those pegmatites, and most contain only enough to furnish collectors with more or less ornamental and uncommon minerals. New England has long had numberless collectors of minerals, and the mineralogists of its various schools have published many papers on the pegmatitic minerals, including those of the rare alkalis, but none of the papers have dealt with estimates of quantities. In this paper we have tried to place the emphasis on quantity rather than on mineralogy.

Jan 1, 1943

By Eugene H. Skinner

The 7-mile Flathead Tunnel, located in the central Salish Mountains of northwestern Montana, was constructed between 1966 and 1969, With the contract awarded April 19, 1966, drill and blast tunnel excavation began September 30, 1966, and was completed June 21, 1968, in 488 tunnel-driving days, Peak advance was 66 feet per day. On June 27, 1969, all tunnel concrete lining was completed. Average wall and arch concrete placing rates exceeded 1,700 cubic yards daily, with nearly half of the concrete placed during a severe winter season. Major cost savings in concrete tunnel lining were achieved through a value engineering clause in the contract. Achieving consistent results and high rates of placement in concrete lining ranked equal to ground control in overall tunnel problems. Ground control problems exceeded expectations and were of continual concern throughout excavation, One support collapse in the tunnel and one portal slide condition developed during construction. Critical surface geologic exposures were largely obscured; only a portion could be accurately projected underground, An instrumentation program to gather basic data on rock defamation near the heading face for support purposes was a pioneering effort. The Flathead Tunnel was placed in service on November 7, 1970.

Jan 1, 1974

VOLUME I Volume I of this three-volume report is the result of development of a comprehensive, coordinated approach to site data-acquisition activities to produce key plans and reports during the evaluation and development of a surface coal mine. A logic diagram illustrates activities in the planning and decision-making process from exploration through post-mining monitoring. The report briefly discusses major elements, other than the site environment, which influence development of mining and reclamation plans and refers to other readily available literature for details outside the scope of this study. The essence of the rationale is shown to be the 1 employment of necessary skills at the proper time to evaluate specific data ' requirements and integrate them into a cost-effective program to produce initial and major feasibility reports, mining, and reclamation plans, and the environmental impact assessment.

Jan 1, 1976

By L. Ozdemir

An investigation was made to determine the mechanical properties of oil shale at elevated temperatures and confining pressures, the thermal properties at elevated temperatures, and to provide mathematical models for mine design for in situ oil shale retorting. A review of current activity in in situ retorting is included with a comprehensive list of references. Tests were run at temperatures from 20°C to 500°C and confining pressures to 1500 psi with shale of 10 to 30 gallons per ton. A major loss of strength occured in heating 140°C with a partial regain from 380°C to 500°C. Higher grade shale had lower compressive strength. Elastic properties showed large variations. Brazilian tensile strength showed a similar temperature sensitivity as the compressive strength. Equations were developed for each property in terms of grade, temperature and pressure. Thermal, electrical and acoustical properties showed anomalies through the temperature range. Creep is a major factor in overall deformation of heated shale. Oil shale was found to be an excellent insulator. Loss of pillar support area at 800 hours of heating would be about 10 percent. Good correlation was found between a finite element model using the developed properties and an in situ heater test.

Jan 1, 1981

By K. B. Nowels

"INTRODUCTION For the last several years the oil industry has been turning more and more toward conservation arid the study of related production problems. It is generally conceded that ultimate recovery is increased by holding the natural gas in thy sand which is net needed in lifting the oil. The retained gas lowers the viscosity and surface tension of the oil and helps flow the oil from the sand. Lewis states that ""while the operator can not control the original conditions of energy and resistance in the sand, he can partly control the efficiency of expulsion. As it is the energy contained in the compressed and absorbed gas rather than the oil that is exhausted, it is but logical to judge the efficiency of a producing method largely by the relative quantities of gas produced with each barrel of oil. If by a change in method the producer lessons the proportion of gas with each barrel of oil, he should increase the total recovery- of oil correspondingly, even if the rate of production is temporarily reduced somewhat.""The effect of ""pinching in"" or controlling the flow of oil wells in an effort to lessen the proportion of has never been definitely known. The general belief has been that ""pinching"" a flowing well causes the oil and gas volumes to be reduced proportionately, maintaining the same gas-oil ratio as before the reduction in flow was made. Studies of gas-oil ratios in many fields have shown that much gas has been wasted, insofar as its effectiveness in oil production is concerned. Swigart and Bopp carried."

Oct 1, 1927

By John Nagy, Hylton R. Brown, Irving Hartman

"INTRODUCTION The tests described in this publication were planned to provide information on the explosibility of metal-powder dust clouds. This subject has become increasingly important because of the large quantity and variety of metallic powders now used for military and industrial purposes. To provide the increased amounts of metallic powders needed in the manufacture of munitions and to supply the demand created by the rapid growth of powder metallurgy, existing metal-powder plants have been enlarged, production schedules accelerated, and new plants erected. In some cases new methods of producing metal powders have been developed. This increased production and the development of new manufacturing methods have caused an increase in the number of metal-powder fires and explosions, with accompanying heavy loss of life and property. These have emphasized the need for information on methods of providing protection against hazards inherent in the production and handling of powdered metals. This paper gives results of laboratory inflammability and explosibility tests made to April 1, 1943, and is a progress report. Many descriptive details have been omitted purposely; they will supplied in a later publication, expected to be a Bureau of Mines bulletin."

Oct 1, 1943

By L. C. IlsLey

"There is an old saying that ""It is too late to lock the stable after the horse is stolen"". Is not this just what is being done by many mine operators today when it comes to buying safe electrical equipment for gaseous and dusty coal mines?The ""open type"" of electrical equipment or even the ""half safe"" type represents the unlocked stable. After the mine disaster, and after men have lost their lives, the lock is put on - that is, safer equipment is installed.For example, an open type of electric coal drill was used in a gaseous mine in West Virginia, This was the probable cause of the death of 27 men. A half safe type of electric coal-cutting machine was used in a gaseous mine in Pennsylvania. This was likely the cause of the death of 36 men. An unapproved, unsafe type of flame safety lamp was used in a gaseous and dusty mine in Utah. This was the all¬eged cause of the death of 171 men. All three disasters happened within the last six months, and seem to have been avoidable if proper equipment had been used.It is understood that more rigid requirements will be enforced in West Virginia. The committee of State mine inspectors made definite recommendation for im¬proving the conditions in the given mine in Pennsylvania. The Industrial Commission of Utah have already issued new orders which will remedy the use of unsafe lamps in that State.These acts and recommendation are all good and will help prevent accidents in those States in the future. Is it not a pity that such recommendations and order were not made a little earlier before the tell of life had been exacted? Is it not a pity that other States will not take these lessons to heart and safeguard their mines before and not after disasters take place?Electric current can cause accidents in five general ways as follows: (1) By shock to persons; (2) by igniting powder; (3) by igniting gas; (4) by igniting coal dust; and (5) by setting fire to inflammable material such as timber and coal. A great many accidents from these causes are preventable if proper care is taken. Most of the accidents caused by sparks and flashes from electrical apparatus would not take place if approved electrical equipment was used. By approved equipment, the writer means equipment that has been tested and formally approved by the Bureau of Mines. So far as known, up to the present time, no disasters have been caused by sparks or flashes from equipment having the Bureau's approval."

Jul 1, 1924

By James M. Link

A program was initiated tinder sponsorship of the U. S. Bureau of Mines to investigate pipeline behavior of raw and spent oil shale slurries. Slurries were recirculated in pipeline loops with 150-mm and 200-mm diameter horizontal test sections and a 150 -mm diameter vertical test section. Slurry concentrations from 10 to 60 weight percent were investigated. Critical and deposition velocities were observed. Head losses were measured at various velocities. Rheology measurements were made on representative homogeneous samples from the pipeline. From these data, pipeline energy requirements were predicted by computer and compared to pipeline data. Computer programs were also used to analyze pipeline data for two flow models: 1. Heterogeneous flow regime for coarse, settling slurries 2. Homogeneous flow regime for nonsettling suspensions The economics of slurry transport of raw and spent shale were examined. Cost estimates encompassed a range of pipe diameters to transport a wide range of throughputs of both raw and spent shale. Similar estimates were made for conveyor belt systems to provide a valid cost comparison. Economic comparisons are valid in a general sense, but a specific study must be made to determine the cost advantages of hydraulic transport for a given mine.

Jan 1, 1977

By John Organiscak

A majority of continuous mining machines employ a water spray system and a machine mounted flooded-bed scrubber to suppress and capture dust during coal mining. These machine mounted dust control systems must be designed to function within the localized face ventilation system at the mining section to control both dust and methane. Spray systems can impede or improve the scrubber effectiveness in controlling dust or methane at the mining face. Laboratory experiments were conducted to examine the effect of spray type, spray pressure, machine body blocking sprays, and scrubber airflow on dust and gas levels while using a 12.2 m (40 ft) exhaust ventilation curtain setback from the face. These experiments were conducted with the mining machine positioned at the end of a simulated 6.1 m (20 ft) sump and slab cut. Results indicate that the hollow cone nozzles with blocking sprays best complemented the flooded-bed scrubber performance in an exhaust ventilation system. This external spray system notably reduced dust and gas levels on the off-curtain side of the mining machine for both the sump and slab cut as compared to the flat spray nozzles. Higher scrubber airflows reduced dust and gas levels on the curtain side and in the return of the continuous mining machine. The remote operator position, located on the off curtain side and parallel to the inlet end of the exhaust curtain, sustained the most stable and lowest dust levels around the mining machine.

Jan 1, 2010

By Danny Riley, Brian Curry, Sandya Govindaraju, James Bain

Hand arm vibration syndrome (HAVS) affects industrial workers exposed to long term hand-transmitted vibration from powered-tools. Peripheral neuropathy is a major component of the symptom complex of HAVS. Long term exposure to vibration causes myelin damage in peripheral nerves and reduces nerve conduction velocities in rats1. This study addresses the effects of acute vibration at constant acceleration of 49 m/s2 on myelinated fibers in peripheral nerves in Sprague-Dawley male rats using the ‘rat-tail vibration model,’ which simulates hand-transmitted vibration2. Methods Male Sprague-Dawley rats (~300 g) were assigned to vibration groups: 1 hr continuous vibration at 60 Hz; 4 hr continuous exposure at frequencies of 30, 60, 120 or 800 Hz; immediate and 24 hr following a 4-hr cumulative exposure of continuous and intermittent vibration at 60 Hz. Unanesthetized rats were restrained in cages on a nonvibrating platform with their tails placed on a vibrating stage accelerated by a B&K motor type 4809 and vibrated. Intermittent vibration was delivered in bouts of 10 min vibration alternating with 5 min rest periods repeated over 6 hr. Sham controls were restrained without vibration. After vibration exposure, the rats were anaesthetized, and the ventral nerve trunks from the proximal tail segment 7 were fixed in glutaraldehyde, embedded in epon-araldite and sectioned at 0.5 µm thickness and stained with toludine-blue for morphological quantitative analysis. The total number of myelinated axons in each cross-section of the nerve was counted using the Image J software. Myelin damage was identified by focal increase in area and intensity of toludine-blue staining and unraveling of the myelin sheath. Statistical analysis for comparing sham and the different vibration groups was done using Dunnett’s test. Animal treatment and all surgical procedures were approved by the institutional review board and compiled with the Laboratory Animal Welfare Act. Results The rats tolerated continuous vibration very well and exhibited no behavioral signs of stress. When exposed to intermittent vibration, there was increased vocalization, a startle reflex at the beginning of each bout of vibration, deposition of porphyrin around the eyes and transient hypersensitivity to touch.

Jan 6, 2006

By James H. Rowland

The Mine Improvement and New Emergency Response Act of 2006 (MINER ACT) established a Technical Study Panel (The Panel) to provide recommendations on the utilization of belt air and new technology that may be available for increasing the fire resistance properties of conveyor belt used in underground coal mines. The Panel Report recommended use of the Belt Evaluation Laboratory Test (BELT) as the method for testing and approval of flame resistant conveyor belts used in underground coal mines. The research conducted to establish the correlation of the BELT with large-scale belt fire flammability tests was done using 36- to 42-in wide conveyor belt. Due to today?s coal haulage capacity, the mining industry is using 72-in and wider conveyor belts. The National Institute for Occupational Safety and Health (NIOSH) conducted a study to determine if the BELT will also qualify wider belts as fire resistant for use in underground coal mines. This paper describes the results of recent experiments comparing results from using the BELT and the large-scale tests for six different belts.

Jan 1, 2010

By Thomas K. Matson

The coal reserve base in the Western United States is presented for coalbeds amenable to extraction by underground mining methods. The Federal Bureau of Mines has abstracted data on the quality and quantity of coal resources/reserves from numerous State and Federal publications and modified such data as necessary to allow computer storage and retrieval. Tonnages are compiled by State, county, coalbed, and rank, and allotted to sulfur categories by statistical apportionment. The coal reserve base in those States west of the Mississippi River, amenable to underground mining, is estimated to be approximately 131 billion tons. Of this total, about 30.8 billion tons are bituminous coal, 100.2 billion tons are subbituminous coal, and 126.4 million tons are anthracite. Lignite is not considered for underground mining in this report. Included in this report is a glossary of terms applicable to a classification system for coal resources and reserves as jointly defined by the Bureau of Mines and U.S. Geological Survey. The purpose of this system is to provide for direct comparison or compilation of various resource/reserve data.

Jan 1, 1975

By R. H. Schutz

This publication lists the respiratory protective devices approved by the Bureau of Mines as of December 31, 1968, and the names and addresses of their manufacturers. The purpose of this publication is to inform the public about approved equipment for safe use in mines and mineral and allied industries.

Jan 1, 1969