Search Documents

By Charles Vaught, Kathleen M. Kowalski

Safety and health professionals from all sectors of industry recognize that training is a critical element of an effective safety and health program. A major concern in the mining industry is how to train both an aging workforce and the expected influx of new miners and mine managers as older workers retire. Thus, a review of some of the basic principles of adult learning may be helpful to mine trainers. This paper discusses the principles of adult learning based on research in education and psychology. It stresses the importance of taking a systems approach to training, focusing on the relationship between the environment and technology, and understanding how workers interact with both. The authors argue that the principles of adult learning and a systems approach are fundamental to the delivery of effective training in the mining industry. Examples of training programs developed by the Pittsburgh Research Laboratory of the National Institute for Occupational Safety and Health are presented within two broad performance domains: routine and nonroutine skills. Basics of curriculum development are also briefly presented to provide the mine trainer with a template for program development.

Jan 1, 2002

By William Catron

This paper is one of a series being prepared by the United States Bureau of Mines on mining methods, practices, and cuts in the various reining districts of the United States. The mining methods described are those used in the mines of the Cananea Consolidated Copper Co., a Mexico corporation whose holding company in the United States is the Greene Cananea Copper Co. The mines are at Cananea, Sonora, Mexico, 25 miles directly south of the international boundary, approximately in 31° nor to latitude and 110 to 130° west longitude. Cananea is connected with the boundary towns of Naco and Nogales, Ariz., by a standard-gage railroad.

Jan 1, 1930

By J. M. Stuve

The present Bureau of Mines investigation measured low-temperature heat capacities of NiBr2 (8 to 302 K) and NiS04 (9 to 70 K) by adiabatic calorimetry. The standard entropies (S°, 298.15 K) of NiBr2 and NiS04 were calculated as 29.26 ± 0.06 cal/deg mole and 24.21 0.04 cal/deg mole, respectively. (1 cal = 4.1840 joules.) Heat-of-solution measurements of anhydrous NiBr2 were used to determine its enthalpy of formation (?Hf°, 298.15 K) as -50.64 ± 0.31 kcal/mole. High-temperature enthalpies of NiBr2 and NiS04 were measured by drop calorimetry to 1,150 K and 1,002 K, respectively. Enthalpies, heat capacities, and related formation functions are tabulated to 1,200 K.

Jan 1, 1978

By F. G. Miller, H. C. Miller

Petroleum technologists and progressive operators constantly are striving to increase the percentage of oil that may to recovered from reservoir rocks through wells. The exhaustive studies that have been made of the function of natural as in the production of oil, for example, have aided operators greatly in increasing the quantity of oil recovered from reservoirs. Natural gas dissolved in and otherwise associated under pressure with oil in reservoir rocks, however, is not the only source of energy available for moving oil through sands to wells. In becoming "reservoir—energy conscious" engineers have learned that in many petroleum reservoirs the edgewater flanking the oil accumulation constitutes a potential source of energy capable, through proper control, of increasing oil—recovery efficiencies materially. No longer is the encroachment of water into the oil— and gas—filled tart of the reservoir considered as an evil to be combatted by devious methods but rather a natural consequence, incident to the withdrawal of nil and as from the wells, that may be used advantageously in lengthening the flowing life of wells and increasing the economic recovery of oil and gas.

Mar 1, 1938

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 R. L. Derick

On a regular basis, mine personnel should obtain air samples directly from active underground areas as well as remotely from sealed locations. These samples provide mine officials with data relative to the makeup of the various atmospheres. Should conditions underground change, these results can provide a baseline that can assist officials in determining the extent of change. Relating the concentrations of individual gases to time, applying gases to equations, and examining their change over time are tools that have been successfully used to determine if a heating event exists and, if so, the extent of the emergency. These atmospheric status equations have either been developed for the mining industry or adapted from other industries. They serve as tools to assist personnel in determining the condition of underground mine atmospheres. As long as the problem area continues to be ventilated, certain gases, gas ratios, and equations can be used to determine if a fire exists, what type of material could be burning, and what quantity of coal is burning. Once the mine or the involved section has been temporarily sealed, gases, ratios, and gas-derived equations can assist personnel in determining how conditions within the sealed volume are changing over time. To alleviate potential explosions when fresh air is once again introduced into the sealed volume, equations and a diagram have been developed to predict the likelihood of an explosive atmosphere. Similarly, prior to commencing recovery of a mine or section, equations exist that can assist in determining if the fire will rekindle when air is reintroduced. This paper serves as an overview to remind and/or instruct readers about gas-sampling methodologies and gas analyses to assist in determining the status of underground atmospheres.

During development mining, ventilation capacity may decrease and the ventilation requirements may depart from initially planned values depending on the mining rate, increases in the methane emission rate, and changes in ventilation airway leakages. Insufficient ventilation air quantities and the occurrences of high methane liberation rates can overwhelm the existing quantity of ventilation air and result in elevated levels of methane gas during development mining. This condition can both limit the development of that section and increase the risk for an ignition that may lead to an explosion. Thus, the prediction of ventilation air requirements prior to mining can enhance worker safety by reducing the likelihood that explosive methane-air mixtures form. This study presents an approach for prediction of methane inflow rates using coalbed methane reservoir modeling. For this purpose, a two-phase coalbed reservoir model of a three-entry type roadway is developed. In the model, grids are dynamically controlled to simulate development of entries. Examples are given for methane inflow and ventilation air requirements as a function of mining rate, development section length, mining height, and the existence of degasification boreholes. This technology can be used to limit the methane concentrations occurring as a result of the influences of various coalbed and operational parameters.

Jan 1, 2008

By David C. Oyler

The U.S. Bureau of Mines studied the interaction of longwall shield supports and adjacent strata at the Meigs No. 31 Mine in southeastern Ohio. Twenty-three legs of twenty shields at midface were instrumented with pressure transducers and monitored for 11 weeks. During the project, leg setting pressures were reduced twice to determine the effect of setting pressure on shield-strata interaction. No correlation was observed between setting pressure and leg loading rates. The shield loading profiles were consistent with a model in which the roof consists of two zones, a thin immediate roof loading the shields well below the typical setting force and a main roof zone essentially supported by the coal and gob and loading shields through its convergence. This model was used to develop an equation for estimating average loading rates at the site. The only variable of the equation is time, and the equation consists of an exponential term to account for the immediate roof loading and a linear term to account for main roof loading. The equation gave good correlation with average loading rates, but the variation in loading from cycle to cycle was too great for the equation to give good predictions of individual cycle loading rates.

Jan 1, 2010

By J. R. Thoenen

In Progress Report 1,4/ a number of facto mere demonstrated and conclusions drawn from experimental tests and records made during commercial blasting operations at a number of quarries. For example, the tests showed (1) that vibrations received on outcrops were of comparatively

Jan 1, 1938

By Jon C. Volkwein

In This Chapter [Instruments for measuring dust How to calculate the amount of dust from a source How to get a valid concentration measurement Sampling to assess control technology effectiveness] When there is more than one source of dust, sampling may be required to find which dust sources are most significant. Then, efforts to reduce dust can be concentrated where they will have the most impact. This chapter explains how to perform dust source sampling. It describes two kinds of instruments that are available and discusses their limitations. It explains how environmental variables such as concentration gradients, dust dilution, and production changes can impact dust measurements. It also suggests practical ways to improve the validity of dust source measurements under adverse conditions, such as high-velocity airflow or the presence of water mist in the air. [Dust source sampling at coal mine longwalls and at tunnels is more complicated. Chapters 3 and 7 have more information on sampling in those circumstances.] TWO KINDS OF INSTRUMENTS FOR MEASURING DUST Gravimetric samplers. The conventional gravimetric sampler is a good device for measuring dust because it is the instrument used for compliance measurements. This dust sampler consists of an air pump, a small cyclone that separates out the respirable size fraction of the dust cloud, and a filter to collect the respirable dust. In coal mines, the Mine Safety and Health Administration (MSHA)-approved gravimetric sampler uses a 10-mm Dorr-Oliver cyclone operating at an airflow of 2.0 L/min [30 CFR78 74 (2002)]. A correction factor of 1.38 is applied to make the results consistent with the U.K. MRE sampler, the instrument on which the 2.0 mg/m3 coal dust standard is based.

Jan 6, 2003

By M. J. Jackson

MIGRATOM is a third-generation PC-based computer program developed by the U.S. Bureau of Mines for geophysical tomography. Like its predecessors, BOMTOM and BOMCRATR, MIGRA TOM was developed to enable users to address a variety of mining-related problems by mathematically reconstructing the distribution of physical properties in a rock mass, using measurements of travel time or amplitude of wave energy propagated through the rock mass. Examples of applications include lithologic characterization, fracture detection, fluid monitoring, stress evaluation, and blast assessment. The resolution and accuracy of tomographic reconstructions generally depend very strongly on the geometry of source and receiver locations. In many practical applications, such as cross-borehole tomography, limited coverage results in nonunique reconstructions. MIGRATOM follows the precedent of BOMTOM and BOMCRATR in allowing the user to constrain the inversion, in order to reduce the nonuniqueness problem. A new approach to application of constraints implemented in MIGRATOM is based on fuzzy logic techniques. Refraction of wave energy is modeled in MIGRATOM using an approach based on Huygens' Principle. Propagation of a continuous wavefront is modeled as a constructive interference phenomenon, which obviates the shadow-zone problem that affects conventional ray-tracing calculations. MIGRATOM has been tested with both synthetic and field data sets.

Jan 1, 2010

By Joseph J. Wallace

1. From the standpoint of present production and recoverable reserves, there are two beds of major importance in Allegheny County -Pittsburgh and Upper Freeport -and one of lesser importance -Redstone. 2. Known measured and indicated reserves in all beds, based on a minimum thickness of 14 inches and 1,800 short tons per acre-foot of coal in place, are estimated at 832 million short tons as of January 1, 1953. Of this total, 768 million short tons is in beds 28 inches and more thick. Areas in some beds were omitted from the estimate because available data relative to the bed characteristics are too meager for making an estimate that conforms with the definitions of measured and indicated coal adopted for this study. Should future drilling or development prove reserves in these areas, such reserves should be added to the total estimated reserves.

Jan 1, 1953

By Arno C. Fieldner

From July 1, 1949, to July 1, 1950, the Bureau of Mines conducted the research and technologic work on coal and coal products that is summarized in this report. The research, described in this fifteenth of a series of resumes, is presented in more detail in publications (see footnote references) that appeared during the fiscal year, though in some cases research data are given that have not been published elsewhere. Results of research in the experimental coal mine, on explosives, and on gas and dust explosions will be found in Bureau of Mines Report of Investigations 4228, Annual Report of Research and Technologic Work on Explosives, Explosions, and Flames, Fiscal Year 1950. An over-all view of our coal, oil, end natural-gas reserves was presented, and the future possibilities for the, production of synthetic liquid fuels from coal were delineated.3/

Jan 1, 1951

By Fred N. Kissell, Jerry C. J. Tien, Edward D. Thimons

At coal mine working faces, simultaneous application of three basic elements reduces the methane explosion hazard: (1) adequate ventilation, (2) regular monitoring of gas concentrations, and (3) the elimination of ignition sources. This paper reviews the application of these elements in a manner relevant to Chinese coal mines. Adequate ventilation is provided by using the mine entries to convey air for the long distances between the mine portal and the working sections (main ventilation systems) and then using line brattice or ventilation duct (face ventilation systems) to convey air the last hundred meters to the working face where coal is broken and removed. The air quantity provided is enough to safely dilute methane and the air velocity is enough to prevent layering. Gas concentrations are regularly monitored in accordance with regulations using knowledge of the circumstances under which the highest concentrations are likely to be found. Ignition sources are eliminated by ensuring that electrical equipment does not ignite methane, that sparking from cutter picks is minimized, and that smoking by workers is strictly forbidden. Risk-reduction studies using fault-tree analysis have shown that large reductions in explosion risk only result from multiple preventive actions. For example, a ventilation upgrade or a methane monitor upgrade by itself offers risk reductions under 50 pct. A risk reduction of 90 pct. or more would typically require much more. Other studies have shown that the everyday vigilance of those working underground is as important as engineering design.

By William Porter

Hand scaling is a physically demanding job and is responsible for numerous overexertion injuries in mining. This experiment studied rib scaling from an elevated bucket to examine force generation capabilities and electromyographic responses to a prying subtask. Subjects exerted force using two bars (steel and fiberglass) at five target heights. Work height significantly affected peak prying force during scaling activities with highest force capacity at the lowest level (p = 0.0188). Bar type did not affect force generation (p = 0.7843): However, use of the fiberglass bar required significantly more muscle activity to achieve the same force (p < 0.05). It was concluded that miners should scale points on the rock face that are below their knees, and reposition the bucket as often as necessary to do so. Additional research is needed to fully understand the impact of bar type on the physical demands of an entire scaling task.

Jan 1, 2006

By D. C. Crowell, A. G. Loomis

Both Dimensional and Inspectional Analysis are developed from fundamental concepts , and dimensionless groups are derived which represent the viscous , capillary , and gravitational forces existing in two - phase , incompressible flow in petroleum reservoirs . It is shown how properly scaled models may be devised by means of the foregoing groups . Laboratory measurements with such models faithfully duplicate the behavior of the reservoir on a miniature dimensional and compressed time scale , and when all the pertinent variables are evaluated , the model is a most effective tool for the study of complex fluid displacements in the reservoir . Applying the Principle of Similitude , it is shown how dimensionally scaled models are applied to various types of reservoir displacements : ( 1 ) Oil displaced by water , ( 2 ) gas displaced by water , and ( 3 ) miscible displacement . The special case of water displacing gas by imbibition is analyzed , and it is shown that the dimensionally scaled model must be fabricated of sandstone rather than unconsolidated sand , which is generally used in such models . This report is intended to be a review and summary of the application of Dimensional Analysis to reservoir displacement problems for those who are beginning the study of this useful and interesting method .

Jan 1, 1964

By Albert H. Fay

Through the hearty cooperation of the State coal-mine inspectors, the bureau is able to present in this paper a a complete statement of the coal-mine fatalities occurring throughout the United States during the calendar year 1919. The reports received from the inspectors for the year just closed show a reduction of 10.58 per cent in coal-mine fatalities as compared. with 1918, while in 1918 the reduction was 4.3 per cent from 1917 figures. The total number killed was 2,307 in 1919 and 2,580 in 1918, a reduction of 273. There was a decrease of 128, or 25 per cent, in fa tali ties resulting from mine cars and locomotives, and a decrease of 198, or 15 per cent, in the fa tali ties due to fall of coal or rock. Surface accidents show a decline of about 25 per cent as compared with the previous year. There were, however, increases in accidents due to gas and dust explosions and also explosives. There occurred during the year nine disasters in which five or more men were killed, representing a total of 201 fatalities. The worst disaster of the year was the one occurring at the Baltimore Tunnel No. 2, Wilkes-Barre, Pa., resulting from the explosion or burning of a number of kegs of powder, by which 92 lives were lost. This disaster emphasizes the need for stricter regulations relating to hauling men and explosives into the mine at the same time. The question of whether electricity was responsible or not does not affect the consideration of the various dangers which arise in underground transportation and handling of explosiveB. At best the handling and hauling of explo.sives is hazardous and such being the case, no one, other than the necessary attendants, should be permitted to ride in cars or cages transporting explosives. As a result of this disaster, the report b of the coroner's jury to the governor of Pennsylvania brings out some important dangers to be avoided in the use and transportation of explosives.

Jan 1, 1920

By E. P. Youngman

Before the World War the use of zirconium and its compounds was largely experimental and confined almost wholly to Germany and Austria . Occasionally small lots of zirconium ore had been produced in the United States ( 1,000 pounds in 1869 , 26 tons in 1883 , and 3,000 pounds in 1903 ) and used (with monazite ) in the manufacture of various lighting devices , especially incandescent gas mantles ; but it was not until 1906 that the discovery of the natural zirconium oxide in large quantities near Sao Paulo , Brazil , first gave promise that a zirconium industry eventually might be developed . Edward Rietz , who worked the Brazilian deposits , interested German chemists in extending the use of zirconium , and by 1911 trade journals were listing German firms as manufacturers of compounds or products derived therefrom . For a time zirconia was one of the various oxides used in the Nernst lamp . It was used also for crucibles and hearths as refractory material ; in the manufacture of chemical utensils ; in enamels ; in the place of bismuth subnitrate for defining Röntgenray pictures of the stomach ; as a pigment ; in medicine ; and in a number of other ways . The Germans were credited also with producing a remarkable zirconium steel , which , it was claimed , was much superior to other alloy steels . During the World War the United States Government investigated the possibilities of zirconium , as well as those of other steel -hardening elements , and a large automobile manufacturer actually purchased a substantial quantity of ore with the purpose of employing zirconium in automobile steels . Immediately after the armistice the Government ceased its investigations ; but despite the difficulties experienced by various investigators in reaching concordant results , interest in the use of zirconium as a steel -hardening agent , as well as in other uses of the element and its compounds , continued . In 1918 the Foote Mineral Co. , which had been interested in zirconium for several years , was exploiting the deposit in Brazil formerly worked by the Germans and was supplying zirconia in the form of ore , brick , and cement for refractory and other purposes . About the same time the Electro Metallurgical Co. , which before the entrance of the United States into the war was experimenting with zirconium alloys , supplied in tonnage quantities the demand for these alloys . In 1919 it was reported that American manufacturers , after several years of research, were producing in commercial quantities pure zirconium oxide , which was finding a place in the manufacture of small refractory articles , scorifying dishes , crucibles , tubes , and one- piece furnace linings . In 1920 the lowering of the price of zirconium metal powder ( because of improved metallurgical methods ) promised the production of the metal on a semicommercial scale . In 1924 the Titanium Alloy Manufacturing Co. introduced a new opacifying agent , " Opax , " made from zircon . A year or two later some of the large pottery manufacturers became interested in the use of zirconium oxide as an opacifying agent , the increased production of titanium pigments having resulted in the production of zirconium as a by-product at a price that could compete with tin oxide . In 1928 it was reported that the industrial use of zirconium oxide was increasing steadily in the manufacture of brick , crucibles , and other refractory products , such as high- temperature cements . However , the reluctance of producers to install additional and more suitable

Jun 1, 1931

By A. B. Campbell

The mines in the eastern part of the now active region of the Tri-State zinc district of Missouri, Kansas, and Oklahoma have unusually acid water, which during periods of moderate or no rainfall is used in the mills to replace losses from evaporation, seepage-, and tailings disposal. Its use has caused difficulties by corrosion of equipment and by interference with flotation. The growing importance of flotation, which requires good water, and the increasing troubles caused by the corrosion of the milling equipment have prompted the Mississippi Valley Experiment Station of the United States Bureau of Mines, in cooperation With the Missouri School of Mines and Metallurgy, Rolla, Mo., to investigate the action of the waters on flotation and to undertake to develop means of obviating their harmful effects. The work was under the immediate direction of W. T. Schrenk, consulting chemist, United States Bureau of Mines, and professor of chemistry Missouri School of Mines and Metallurgy, and. Will H. Coghill., supervising engineer of the ore dressing section of the United States Bureau of Mines.

Jan 1, 1932

By G. F. Friel, J. C. Edwards

A series of seven underground-coal-mine fire experiments was conducted in the Safety Re-search Coal Mine at the National Institute for Occupational Safety and Health, Pittsburgh Research Laboratory. Coal and styrene-butadiene-rubber conveyor belting were burned upwind of two sensor stations, 18 m and 148 m from the fire source. Exhaust from a diesel locomotive flowed over the fire sources in six of the tests. Metal-oxide-semiconductor (MOS), CO, and optical-path-smoke sensors were positioned at both stations and found to be an optimum set of sensors for the fire discriminations. A representative set of 7,679 samples of CO data and data from the smoke and diesel-exhaust MOS sensors were used as inputs to train a neural network (NN). By testing 42,538 data samples from the seven experiments, all fires were detected by the NN within 9.67 min from the onset of significant changes in the MOS voltages without any false alarms.