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By D. S. Kingery

This study describes five fatal accidents so unusual in occurrence that the chain of circumstances bringing them about may never be duplicated. The intent of this publication is to illustrate that everyone working underground is subjected, at all times, to definite inherent mining hazards and that safety devices, though provided, often are ineffective or not used. It is hoped that a study of these fatal accidents in bituminous-coal mines will show workers and safety engineers that nothing can be taken for granted. Safety planning with continuous study can prevent these unusual accidents as well as the routine recurring types, which cause the majority of coal-mining injuries. The treacherous, fatalistic philosophy that "it can't happen to me" or that "when my time's up I'll get it regardless of what I do," still prevails among individuals and even safety engineers. The individual or safety man who believes in luck as applied to safety should not read any further, since this study was written for the sincere, safety-minded individual who accepts the prevention of all accidents as a challenge to his knowledge, initiative, persuasiveness, and salesmanship.

Jan 1, 1954

By MINE SAFETY BOARD

RECOMMENDATIONS OF THE UNITED STATES BUREAU OF MINES ON CERTAIN QUESTIONS OF SAFETY AS OF FEBRUARY 3 , 1933

Jul 1, 1933

By G. L. Oldright, Virgil Miller

"This paper is the ninth 4 of a series on smelting in the lead blast furnace, and the fourth on modifications brought about by the introduction of richer charges.ACKNOWLEDGMENTSThe authors wish to express their appreciation to Stanley A. Easton, Frank M. Smith, and A. F. Beasley, and to their staff for the whole—hearted cooperation that made it possible to obtain the data in this publication at the Bunker Hill smelter, Kellogg, Idaho.INTRODUCTIONIn tie account written of the conditions obtaining at the tuyere zone in the blast furnaces at Tooele (R. I. 2965) the authors gave references to articles covering (1) the effect of temperature on the equilibrium 2C0 - CO2 + C, (2) experimental work that has been done on learning the gases existing at various elevations in columns of burning coke, (3) extension of this work to the tuyere zone of an iron blast furnace, and (4) the paper itself gave similar analyses of the gaseous oxides of carbon at the tuyere zone of a lead blast furnace and showed the temperatures obtaining there. There were also references in the above paper to the literature on (5) how the lead compounds likely to be present might be ex¬pected to react. A careful study of the original articles selected as references will give a good background for the present work.The following very brief recapitulation may be convenient before considering the tuyere zone in the blast furnaces at Kellogg. The ""producer gas reaction"" (1) of course goes to the left at increasingly higher rates of speed with increase of temperature. When air is blown upward through a grate and a column of hot fine coke alone, oxygen as such penetrates from some 2 to 3 inches only, under the conditions obtaining as to the amount of surface exposed per unit volume of air. When air is blown at about 20 pounds pressure through the tuyeres in the side of an iron blast furnace into a column of coarse coke (plus furnace charge) it may penetrate for 30 inches before the oxygen is entirely used, burning first largely to CO2. Within wide limits, the rate of feeding air into the furnace has practically little effect on the composition of the gases obtaining in the fuel bed of fine coke, this being true particularly of the gases leaving the bed. Some 10.5 inches above the grate the gases contained 22 per cent of CO by volume, and a little further up the CO2 had practically disappeared. This gave the familiar three zones in both the iron blast furnace and the gas producer; in order of entry of the air, in the first the oxygen burned largely to CO2, in the second the CO2 was reduced to CO, and the third the CO2 was practically absent. In the furnaces at Tooele, conditions were somewhat erratic but the first two zones were present, there being, however, no zone in which CO2 and 02 were both entirely absent."

Apr 1, 1931

By David E. Nicholson

In a Bureau of Mines investigation of the dynamic compaction of mine hydraulic backfills, two basic forms of mechanical vibration inducers were used and compared for effectiveness of compaction. Internal compaction, using concrete probe vibrators of various sizes, and external compaction, using plate vibrators} were studied and evaluated for use in underground stopes. An aluminum plate, which was light and displaced sufficient volume to remain afloat in fluid fill, and a steel plate were both used in the external compaction tests. Efficiency of compaction was better in studies conducted with internal probe vibrators. Tests were conducted in an underground backfilled stope with three different-sized probe vibrators (2-, 4-, and 6-inch-diameter) to determine an approximate area of influence. Results showed the areas of influence to be approximately 3, 4, and 5 feet in diameter, respectively, for the three different probes. Physical properties of hydraulic slurries were determined; preferred grain-size distributions, water exudation properties, and water contents of hydraulic slurries are reported. The best compaction results were obtained with moderately well-graded, fully saturated backfills, with slow rates of water exudation, which were capable of remaining in a semifluid state during the compaction process.

Jan 1, 1967

By R. J. Pokora

This Bureau of Mines report is an applications manual that can be used by the nonmetallic mining industry for guidance in installing noise control materials into crushing and screening plants. These noise control modifications were installed and successfully tested at three operating quarries. This report identifies the major noise sources that can be encountered in crushing and screening plants, and discusses the applicable noise control materials and techniques that a plant operator can utilize on a retrofit basis to reduce equipment noise.

Jan 1, 1984

By E. L. Singleton

The electrochemical reduction of aluminum chloride to aluminum was investigated in a closed, two-compartment cell utilizing a molten chloride electrolyte. The externally heated cell was divided into a reduction compartment and a combination AICl3 feed and metal removal compartment. Aluminum was deposited at 700° C on a molten aluminum catbode from a KCI-NaCI-AICI3 electrolyte. The AICl3 content of the electrolyte was replenished by either vapor or solid additions. The chlorine evolved was collected and measured to give a quantitative evaluation of AICl3 reduction. The effects of anode and cathode current densities and AIC13 concentration on anode current efficiencies were studiedo A range of 64 to 84 percent anode current efficiency was obtained with the 25-pound electrolyte capacity cell and related auxiliary equipment.

Jan 1, 1968

By D. Randolph Berry

This manual was prepared to provide essential information to be used when critical decisions pertaining to mine fire recovery or other disaster situations become necessary. It is a state of the art report based upon technology and instruments developed, under a Bureau of Mines Research Contract. A detailed description of the development work and results of full-scale field testing is contained in the Technical Report, Vol. II, of USBM Contract Report H0122045, "Extinguishing Coal Mine Fires by Remote Scaling." Further research and development work has been programmed; consequently, a more complete manual providing detailed instructions and describing available instruments and equipment will be published. Those instruments and special equipment described in this manual must be considered prototype; methodology and applied technology will require special expertise. Consequently, any prospective application of this remote sealing technique will require assistance by the United States Bureau of Mines Research organization and experts from the contractor who developed the basic technology and instruments.

Jan 1, 1973

By K. H. Johnston

This guide was written to furnish the coal industry with a description of techniques, instruments, and clues on how to find abandoned oil and gas wells that have penetrated coal seams. The report includes specific information on searching techniques currently in use by several coal mining companies, gas-transmission companies, and waterflood operators, as well as information on State agencies responsible for the enforcement of laws and the preservation and distribution of data pertaining to the drilling, development, and abandonment of oil and gas wells. Comparative tests were performed with several commercial electronic metal detectors to determine the feasibility of using them to aid in the search for abandoned wells and to determine the instrument most suited for that particular use. The role of methane detectors to locate abandoned wells is described, including a case history. Tests were made to develop an efficient procedure to follow in systematically searching an area for metallic clues or hydrocarbon evidence to abandoned wells. The guide describes, in detail, a search sequence, including the collection of basic data, preparation of the selected area, and the physical search. Methods are given for evaluating the results.

Jan 1, 1973

By Haskiel R. Shell

Methods of chemical analysis of clays for the following constituents are presented: moisture, ignition loss Fe2O3, TiO2, P2O5, CaO, MgO, Na2O, K2O, total. carbon, carbonate carbon total sulfur, soluble salts, and soluble sulfate. In these procedures the attainment of accuracy has been the primary consideration sample was taken to insure accuracy, with ordinary precautions. The procedures may therefore be somewhat somewhat and will not be suited for routine work on samples for which the approximate analysis is already known and in which the need for accuracy is not very exacting. However, the method shod be as a set of detailed directions, that have been tested and shown to yield accurate results with clays and other aluminum silicate minerals. Among these minerals are clays of all types, bentonite bauxite, shale, brick; soil, calcined refractory, and sand. Although some of the methods are Unusual, no particular claim is laid to originality. The material was drawn frail many sources, put together and tested.

Jan 1, 1949

By R. E. Heithecker

The principle of determining volumes of liquid by alternately drawing in and discharging given quantities of the fluid from a confined space or compartment of known volume and mechanically counting the number of displacements is well established. This is true particularly in water measurement. For several years, oil meters employing the same basic principle have beer used for gaging oil production from individual wells, groups of wells, and in some areas for metering the entire production from a property. Especially in areas where there is town-lot drilling and space for tankage is at a premium, oil meters have been used successfully to gale the oil. This facility has obviated the necessity of installing gage tanks. Oil meters also have been used in pipe-line and refinery operations and in loading tankers. Present knowledge e of the subject shows that positive-displacement oil meters can be used for measuring crude oil in the field and elsewhere, provided the meter-counter mechanism is in proper adjustment and the oil has been studied sufficiently to determine the pro-per factor to be applied to the volume as registered by tae meter, possible the adjustment for the shrinkage of the oil caused by liberation of gas from solution.

Jan 1, 1938

By W. M. Traver, A. M. Evans

"INTRODUCTION The Bureau of Mines undertook exploration in the Torlingua district, Texas, during June 1943, at a time when the demand for mercury for war industries was considerably more than the anticipated domestic production. In view of the impressive past production of the mines and the favorable geologic conditions in several underdeveloped areas in the district, the investigation was considered of immediate importance.Prior to initiation of the exploratory program, a preliminary examination of the district was made in August 1942 by A. B. Needham, an engineer of the Bureau of Mines. This examination was followed by a comprehensive geological study by the Federal Geological Survey 3/ and further investigation the Bureau of Mines."

Jan 1, 1947

By A. C. Fieldner

In 1927 the Carbonization Committee of the American Gas Association proposed cooperation with the Bureau of Mines in the development of suitable methods for determining the carbonizing properties of American coals. It was further proposed to apply these methods in the testing of representative coals and to make the information obtained available to the public through Government publications. A cooperative agreement was signed whereby the Gas Association contributed part of the funds necessary for beginning the project and appointed a committee to consult and advise the Bureau in the work. The Advisory Committee has been reappointed each year, and the Bureau has had the benefit of its advice. The composition and carbonizing properties of 33 coals previously tested have been given in technical papers of the Bureau of Mines and in short reports published for the most part in the Proceedings of the American Gas Association. A complete list of publications on the work previous to 1937 is appended to this report. The present report gives the composition and carbonizing properties of seven additional coals from West Virginia. The data include results of blending tests in which Beckley led low-volatile coal was used with all the high-volatile coals except the Alma coal, with which Pocahontas No. 4 coal was used.

Jan 1, 1938

By William P. Diamond

This report presents results of a cooperative research project between the U.S. Bureau of Mines and BethEnergy Mines, Inc. Four coreholes (two before mining and two after mining) were drilled at a longwall mine operating in the Lower Kittanning Coalbed to obtain coal and rock samples from over-lying strata to determine their gas content at various times in the mining cycle. The results of those tests indicate that 91 pct of the gas removed from the overlying strata came from coalbeds. Material balance calculations were made to compare the volume of gas produced both from gob gas vent holes drilled on the panel and gas removed by the mine's ventilation system with the volume of gas removed from strata directly overlying the panel to a height of 275 ft. This analysis indicates that only 40 pct of the total gas produced from the panel actually came from the strata directly overlying the panel. The remaining volume of gas production probably migrated to the longwall gob from overlying, and perhaps underlying, strata immediately adjacent to the panel and perhaps from greater distances downdip because of the establishment of a long-term pressure gradient in the study area.

Jan 1, 2010

By Ren G. Dong, Thomas W. McDowell, John Z. Wu, Chris Warren, Dan E. Welcome, Chun L. Dong

Hand forces are important factors for risk assessment of hand-arm vibration syndrome (HAVS).1 Grip force is one of the most important force components in the operation of powered hand tools. A considerable number of studies on grip force have been reported. It is well known that the grip force applied on a cylindrical handle is not uniformly distributed on each axis across the center of the handle cross-section.2 Therefore, maximum and minimum orientations of grip force exist around the handle. Such orientations have not been clearly identified. In a recently proposed international standard (ISO/CD 15230, 2005),3 it is stated that “the direction of the main gripping force is generally parallel to the z-axis defined in ISO 8727.” 4 This assertion is questionable, and further examinations are required. The objective of this study was to establish a fundamental theory on the distribution of the grip force around cylindrical handles. Methods As shown in Fig. 1, the grip force is defined as a vector composed of normal and shear components (FN & FT) in this study. Fig. 2 shows the hand coordinate system defined in this study, together with the ISO systems.1,4 Based on this novel grip force definition, we derived four fundamental properties and a theorem. More significantly, we formulated a novel hypothesis: similar to Mohr’s circle of stress, the normal and shear components can be represented approximately using an ellipse on the plane of the two force coordinates, as shown in Fig. 3. The maximum and minimum grip normal forces are termed as the first principal grip force (F1) and the second principal grip normal force (F2), respectively. Their corresponding orientations are termed as the first principal grip angle (a1) and the second principal grip angle (a2). A series of experiments were conducted to test this hypothesis. Twelve

Jan 6, 2006

By Kenneth R. Maser

This report describes the development of a system which modifies an existing fly ash-foam remote mine sealing technique to make it capable of impounding water in a fire zone. The modification involves blending equal quantities of fly ash and bentonite to form the bulk of the seal, and blending a thin layer of fly ash and Huron Regulated Set Portland Cement (RSPC) as a coating. The modification replaces the pure fly ash approach, but continues to use a froth foam topping to complete the seal. The modified material system is implemented with minimal complexity by adapting a "Y" connector to the existing delivery system. Each bulk hauler (fly ash and bentonite, or RSPC) will pump into one leg of the 'Y'; and the blending will be controlled by two pinch valves. The development effort has involved an evaluation of potential material systems by using small sample, quarter scale, and full head tests. The small sample tests measured the basic properties of a large number of selected material combinations. Property measurements included capillarity, permeability, shrinkage, and shear strength. As a result of these tests, particular combinations of fly ash-bentonite and fly ash-cement were selected for scale model testing in a 1 /4 scale test facility. These tests simulated, in a scaled manner, the water rise and total head which would be experienced by a seal. The tests indicated that shrinkage in the fly ash-cement combination would always result in leakage; whereas, fly ash-bentonite mixes were impervious to water.

Jan 1, 1974

By Edward D. Thimons

The Bureau of Mines developed a stopping design that allows the stopping to be blown down by strong blast forces without incurring any permanent damage. Trials with the new stopping, dubbed the quick-fix blowout stopping, have been conducted in the Bureau's Safety Research Coal Mine at Bruceton, Pa., and in two New Mexico uranium mines. Results have been favorable in all cases. Compared with conventional brattice stoppings or wood bulkheads, the quick-fix blowout stopping is easier and less time consuming to install, is easier to maintain, and in most cases is just as efficient an air barrier. There is same indication that the shape of the stopping makes it more resistant to blast fore s than the fabric stoppings now in use.

Jan 1, 1976

By John E. Pahlman

The Bureau of Mines conducted column-leaching tests on 25 domestic Mn ores to determine the feasibility of extracting Mn by in situ or heap leaching with dissolved sulfur dioxide (S02) solutions. The ores tested were obtained from deposits in Arizona, Arkansas, California, Colorado. Maine, Minnesota, Nevada, and South Dakota. Dissolved S02 was found to be effective for leaching Mn; extractions greater than 90 pct were obtained with solution application rates of 1 mL/min from uncalcined, minus 2.5-plus 1.3-cm ore pieces. Leaching these ores with solutions containing only 5-wt-pct S02 and no added H2S04 resulted in Mn being selectively extracted over Fe except when Fe was present as goethite or siderite. Ca solubilization was inhibited by controlling the solution application rate (1 mL/min). The rate of leaching was found to be principally dependent upon the rate at which the leaching solution can penetrate the ore, since the solubilization of Mn upon contact with S02 was observed to be rapid. Despite low water permeabilities of the ores (as low as 10-2 to 10-4 darcy). greater than 90 pct of the Mn was extracted from even the largest ore pieces tested (approximately 10 cm in diameter). It appears, therefore. that leaching Mn opens up the pores, allowing penetration of the leach solution into the ore pieces.

Jan 1, 1988

By Francis C. Lincoln

"INTRODUCTION As part of a general investigation of the zinc-producing area of southwestern Wisconsin, the Bureau of Mines undertook a limited amount of exploratory drilling in the immediate vicinity of the New Dale Rundell mine, in the Mifflin District of Iowa County, Wisc.The work was carried out during the early part of 1945, at a time when all effort was being directed toward increasing production of metals important to the Nation's war program. Bureau of Mines engineers decided to conduct exploration at the New Dale Rundell mine after a preliminary study of available data showed a reasonable possibility of indicating an important deposit. Before the Bureau of Mines investigation, 50 holes had been drilled in the vicinity. Of this number, 18 encountered ore of minable grade. Subsequently the mine was developed and operated for a brief period; however, work was stopped before all of the ore disclosed by drilling had been mined. There appeared to be a correlation between the ore shown by the drilling in the New Dale Rundell mine and another disclosure some 1,500 feet to the northwest. The Bureau of Mines exploration was pinned to explore this possible correlation. Of the 7 holes drilled by the Bureau of Mines, 3 disclosed minable ore beyond the limits of previous drilling."

Aug 1, 1946

By R. T. MacMillan

A number of chemical techniques have been applied to manganese ores from three areas of Aroostook County, Maine. Although large tonnages of these ores have been proved, they are low grade, and their exploitation has awaited a suitable beneficiation scheme. As conventional ore-dressing methods had failed to yield satisfactory results, attention was turned to chemical procedures. Leaching with dilute (7-percent) H2S04 extracted over 90 percent of the manganese from ore of the Dudley farm area, consuming 3.8 pounds of acid per pound of manganese extracted. Ores from the Littleton Ridge and Maple Mountain-Hovey Mountain areas were less amenable to this treatment, yielding approximately 80 and 60 percent of their Mn content, respectively. To increase the percentage extraction of manganese in the latter two ores, a number of factors were varied, including (1) acid concentration in the extracting solution, (2) ratio of acid to Mn in the slurry, and (3) preliminary heat treatment of the ore with a reducing agent. Other acids, including HNO3, HC1, and H2SO3, were tried also; however, no significant improvements in the Mn leached from Maple Mountain-Hovey Mountain ore were made. The manganese extraction of Littleton Ridge ore was raised to 90 percent by providing 9 to 11 pounds of HNO3 per pound of Mn in the ore.

Jan 1, 1954

By M. J. Sapko

The pressure and flame development of the methane-air-nitrogen system was investigated in the Bureau's l2-foot-diameter sphere to define buoyancy effects and to develop relationships for predicting venting requirements. Pressure rise (?P) is defined as a function of time (t) and nitrogen dilution and is shown to deviate noticeably from the cubic law (?P = kt3), depending upon the period of combustion and the mixture composition. Corresponding flame speed (Sf) and burning velocity (Su) data are given which show that Sf is time dependent and that Na dilution has a greater effect than air dilution in inhibiting the flame propagation. The Su data agree with "accepted" values and are unique in that they are based on much larger flames than those used in other investigations. Downward propagation limits are shown to depend mainly upon buoyant forces, which can affect the burning of even stoichiometric CH4-air systems. Theoretical expressions, based on the mixture burning velocity and expansion ratio, are given for predicting the venting requirements for ignitions of hydrocarbon-air-nitrogen mixtures in spherical or cubical enclosures.

Jan 1, 1976