Search Documents

In 2007, a total of 7,199 sand and gravel mining operations reported employment to the Mine Safety and Health Administration (MSHA).1 ? Sand and gravel mines were the largest mining sector, comprising 48.4% of all mining operations. ? Sand and gravel mines were found throughout all 50 states and Puerto Rico.

Aug 1, 2009

By Robert S. Schechter

A minitest, consisting of an injection/production well and at least two observation wells designed to detect the arrival of injected fluid leached minerals, and nonideal flow, is considered in this report. The test goals are to determine the susceptibility of the host formation to uranium leaching, kinetic parameters to scale the process, and to facilitate site restoration. This report considers permeability and mineral heterogeneities and other oxidant-competing minerals. To circumvent these nonidealities, which obscure the results, methods of interpretation have been proposed and tested by a computer simulator. In complex cases, clear-cut methods of interpretation were not found; but in every case the design of a test most susceptible to interpretation has been considered. The minitest is operationally simple and can be completed in a short time. With the correct design and interpretation it can return information to evaluate economics, ensure satisfactory leachate performance, scale to larger operations, and to identify restoration problems.

Jan 1, 1983

By A. J. Kraemer

This report on research and experimentation by the Federal Bureau of Mines on technologic and scientific problems of the petroleum and natural gas industries presents a resume of work from July 1, 1953, to June 30, 1956. The preceding report, for the fiscal year ended June 30, 1953,3/ indicated continuation of the Bureau's program of petroleum and natural gas research of world-wide significance, which began in 1910. The petroleum and natural gas research of the Bureau of Mines is divided into five main categories: (1) Production of petroleum and natural gas, (2) transportation and storage, (3) petroleum chemistry and refining, (4) thermodynamics, and (5) economics.

Jan 1, 1959

By Leo A. Schrider

A prediction for oil recovery from a pilot waterflood in the Kane oil- field, located in Elk, Forest, and McKean Counties, Pa., was made and compared to actual field performance. Water-injection and production histories, well logs, other field data, and results from laboratory tests of core material were used in this analysis. Performance of the pilot waterflood, initiated in January 1963, was predicted using a modified Craig, Geffen, and Morse calculation technique. Maximum recovery from this low permeable, preferentially oil-wet formation was predicted to be about 22,500 barrels of oil after 300,000 barrels of water had been injected into the pilot waterflood area. After additional field data were collected it became necessary to reevaluate the pilot waterflood area. The gas saturation prior to the waterflood was estimated to have been 20 percent, based on an assumption regarding the required volume of water injected to initiate oil production. In view of the actual field performance, a gas saturation of 13 percent is indicated. When this gas saturation and the method originally proposed by Craig and others are used) the predicted results are more representative. In December 1965, field performance was further analyzed using a hyperbolic-decline curve as presented by Arps. Based upon this evaluation method, the pilot water flood in the Kane sand should produce 37,000 to 42,000 barrels of oil with the injection of 300,000 barrels of water into the pattern. By continuing this secondary-recovery project to a reasonable economic limit, ultimate oil recovery may be as much as 50,000 to 55,000 barrels, or 129 to 142 barrels per acre-foot from 36.5 acres.

Jan 1, 1967

By W. P. Yant

This report describes result of a study of the carbon monoxide and particulate matter in the air of the Holland, Tunnel and metropolitan New York made by the Bureau of Mines (which had participated in the development

Jan 1, 1941

By Jack L. Henry

The monocarbide region of the ternary system U-C-O has been investigated at 1,700° C as the first phase of a more extensive study of a portion of the four-component system U-C-O-N. An area bounded by the following compositional limits in atomic percent was studied: U, 44 to 55; C, 30 to 60; 0, 0.2 to 20. Compacts composed of mixtures of uranium, graphite, and uranium dioxide powders were sintered at 1,700° C under an equilibrium pressure of carbon monoxide to produce uranium oxycarbide specimens having a variety of compositions. Sintered specimens were evaluated by X-ray, chemical analysis, and ceramographic techniques. Solid-solution boundaries and phase relations have been established, and the effects of composition on the lattice parameter as well as the decomposition pressure have been investigated. Oxygen can be substituted for carbon in stoichiometric uranium monocarbide to the extent of about 17 atomic percent at 1,700° C. The composition range of the oxycarbide solid solution extends from about 48 to 51 atomic percent uranium in the low oxygen region. Above 10 atomic percent oxygen the composition range narrows to less than 1 atomic percent uranium. Carbon monoxide exists as a gaseous phase in equilibrium with all compositions which contain oxygen. Five separate phase fields were found bounding the solid-solution area. Other phases within this portion of the system include uranium, uranium dioxide, uranium dicarbide, and uranium sesquicarbide. Decomposition pressures of oxycarbide compositions at 1,700° C have been found to vary from a few microns for stoichiometric and uranium-rich compositions to 35 torr for carbon-oxygen-rich specimens. Lattice parameters were found to depend upon the U to C + 0 ratio as well upon the extent of substitution of oxygen into the stoichiometric monocarbide lattice.

Jan 1, 1967

By Lloyd Williams

1. This investigation shows that the Poplar Creek is the most important bed in Scott County from a production standpoint. Although the Poplar Creek bed contains the largest reserve, the Big Mary has a larger recoverable reserve. Estimates of reserves also have been made for the Pewee, Red Ash, Windrock, Upper Pioneer, Jellico, and White Oak beds. 2. Known measured and indicated reserves of coal, based on a minimum bed thickness of 14 inches and on 1,800 short tons per acre-foot of coal in place, are estimated to be 143 million tons as of January 1, 1954. Of this total, 74 million tons is in beds 28 inches and more thick. Areas in each bed 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, 1956

By D. Harrington

Every few weeks United States newspapers of 25 or 30 years age ran scare-heads telling of some mine disaster, which was a first-page attraction for a day or two and then was forgotton until another disaster occurred a few weeks later. Interspersed with these disasters were the so-called sniping mine accidents, causing the death of one or two mine workers. The summation of all types of mine fatalities usually exceeded 3,000 a year. In the period 1906-10, inclusive, there wore 84 major explosion disasters (or about 17 per year) in united States coal mines; the fatalities resulting from those disasters numbered 2,388 for the 5-year period. These frightful catastrophies helped to cause the total number of fatalities in our coal mines for the 5 years (including the fatalities from major explosions) to reach the enormous total of 13,288, an average of 2,658 per year. In addition, some hundreds of other typos of mining accidents swelled the annual fatality list to upwards of 3,000. This admittedly deplorable condition created so much Nation-wide comment that Congress was impressed with the necessity of having something done by the Federal Government with a view to trying to halt at least sonic of the excessive loss of life in our mines; in consequence, the Bureau of Mines was created and began to function in July 1910.

Jan 1, 1935

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

By R. S. Rosso

A program to investigate the effects of hardened washers on the uniformity of roof bolt tension and the resulting ground control in an underground mine was carried out. The complete roof bolt installation and roof bolt loads, mine convergence, and bed separation were monitored for a period of five months. The results show no evidence to support or refute the theory that mechanical roof bolts offer better support when they are installed with a high uniformity of tension. Also shown is the fact that if the bolts are installed with a maximum deviation from the mean torque of ±15% the addition of hardened washers significantly improved the uniformity of the installed tensions in the roof bolts.

Jan 1, 1977

By Noel N. Moebs

This report summarizes a U.S. Bureau of Mines study on the application of geotechnology to identify and minimize ground control hazards in talc mining operations in northwest Georgia. The major ground control hazard is pillar sloughing attributed to the steeply dipping orientation of a pronounced foliation in the talc ore body. The sloughing problem, which gradually reduces the effective support area of a pillar through attrition, can be minimized by appropriate artificial support, as determined by a rock classification system, and by a more uniform pillar design. A boundary element model confirmed the advantages of using a uniform pillar design to avoid excessive loads on portions of irregular pillars. Instrumentation to measure roof convergence and pillar loading was installed at selected locations in an active talc mine but failed to detect any significant changes, suggesting that the gneiss hanging wall constitutes a strong roof that probably can support large spans between pillars and permit high extraction ratios. This interpretation also is supported by a rock classification of the hanging wall gneiss.

Jan 1, 2010

By d&apos, D. V. Andrea

Nine rock properties were determined for rocks coming from 49 locations and having a wide range of compressive strengths. Plots of the nine rock properties versus each other were prepared. A stepwise multiple linear regression analysis was performed to obtain several equations for predicting compressive strength. Both linear and curvilinear relationships were assumed between compressive strength and the other rock properties. The prediction equations had multiple correlation coefficients ranging from 0.947 for an equation with 1 variable (point load tensile strength) to 0.986 for an equation with 25 variables. Of the properties tested only point load tensile strength could be used alone to estimate compressive strength with fair accuracy.

Jan 1, 1965

By James Westfield

This report covers the calendar year 1953 and has been prepared and submitted in accordance with the provisions of Sec. 106(a) and Sec. 212(c) of the Federal Coal Mine Safety Act (66 Stat. 692; 30 U.S.C. Secs. 451-483). During this first full calendar year of operations under the Federal Coal Mine Safety Act, the coal-mining industry of the United States attained the best injury records in its history - improving the former best records (made in 1952) by 91 fatal and 10,020 nonfatal injuries. Whereas, the mandatory provisions of the act were intended and designed to prevent major mine disasters, apparently the effects have reached beyond the scope thereof in reducing mine accidents generally.

Jan 1, 1954

By Douglas A. Crum

The Taylor's friction circle method for slope stability analysis can be extended to incorporate multiple circles defining the slip surface in a failure mechanism so that it is a workable method for bearing capacity calculations of foundations and rotational failures of retaining walls and similar structures. The U.S. Bureau of Mines has further extended the multiple-circle method to include friction in the material strength and to utilize computational schemes such that this method can be programmed with optimization capabilities rather than being used as a graphical or semigraphical method. Some examples are given that demonstrate ultimate bearing capacity calculations of embedded foundations with eccentric loads and nearby slopes.

Jan 1, 2010

By E. G. King

An earlier Bureau of Mines report4 provided low-temperature heat-capacity and entropy data for three sodium vanadates. This report continues the study of vanadates by presenting analogous data for three crystalline calcium vanadates - calcium metavanadate (CaV206), calcium pyrovanadate (Ca2V2O7), and calcium orthovanadate (Ca3V208). No similar data for these compounds have been published previously. MATERIALS All three vanadate samples were prepared by the Bureau of Mines by heating stoichiometric mixtures of reagent-grade calcium carbonate and vanadium pentoxide.5 Calcium metavanadate was prepared at 610° to 660° C. A stoichiometric mixture was heated for 17 days with intervening grindings, mixings, and adjustments of composition, as shown necessary by chemical analysis. The final analysis gave calcium oxide, 23.48 pct. (theoretical, 23.57 pct.) and vanadium pentoxide, 76.32 pct. (theoretical, 76.43 pct.). The sample also contained 0.11 pct. acid-insoluble matter. The X-ray diffracton pattern showed no lines of free calcium or vanadium oxides. No X-ray diffraction patterns were found in the literature for any of these substances.

Jan 1, 1961

By Albert W. Deurbrouck

This report describes the preparation characteristics of 23 coal samples collected from nine of the more significant coalbeds of Fayette County, W. Va. In 1963 almost 5.4 million tons of medium to high volatile B coals of excellent quality for metallurgical and steam markets were produced in Fayette County. Of the 23 coal samples collected 11 would require some upgrading to pro-vide metallurgical quality products, 11 were acceptable as received, and 1 was a noncaking coal. Cleaning these coals to metallurgical standards would require only the removal of the sink 1.58 specific gravity material which would be quite easy as very little near-separating-gravity material was present at this gravity.

Jan 1, 1965

Coal mining in Indiana is limited to the south-western portion of the state, with coal currently being recovered in 19 counties. The coal-producing area of the state covers approximately 6,500 square miles. Although most of the coal in Indiana is recovered by surface mining methods, a small percentage is recovered through underground mining. To date, 40 percent of the known coal reserves have been removed. Indiana has about 33 billion tons of identified coal reserves, of which approximately 17 billion tons are recoverable using current technology. Of this recoverable coal, about 15 billion tons are recoverable by underground mining and 2 billion tons are recoverable by surface mining methods. The State of Indiana has regulated the environmental impacts of coal mining since 1941. Indiana was the second state in the nation to pass legislation requiring mined land reclamation. Its SMCRA regulatory program was approved July 29,1982, and its Abandoned Mine Land Program was approved July 29, 1982.

Jan 1, 1992

By Mackenzie Burnett

An inducer-type pump, capable of injecting dry coal into a hydraulic transport pipeline has been developed and installed in a specially designed and fabricated slurry injector vehicle. The full scale prototype injector system can deliver up to 11 ton/min of coal into an 8-in pipeline t pressures up to 95 lb/in2. The Helical Inducer Injector operates on centrifugal principles with flow passing axially through helical pitched conical rotor. Water is delivered to the pump through an annular slot at the atmospheric pressure coal inlet. The spinning rotor maintains an air-core vortex of water which pressurizes the discharge housing. A screw feeds coal through the open inlet into this vortex. The inner radius of the vortex contracts as pressure is increased, giving a limiting maximum pressure which is proportional to the square of the rotor speed. Below this limit, flow rate, discharge pressure, und rotor speed re independent variables. The self-powered, 4 -in high slurry injector vehicle follows and receives ROM coal from a continuous miner, reduces the top size to 3-in, and delivers the sized coal to the injector feed screw for slurry formation and pumps it through a mobile hose attached to the vehicle's outby end.

Jan 1, 1983

By Lance R. Barron

Over the past decade, the U.S. Bureau of Mines (USBM) has studied longwall gate road stability at four mines in the Book Cliffs and Wasatch Plateau Coalfields of Utah. These operations are characterized by multiple-seam mining, abruptly varying cover depths to 914 m (3;000 ft), and massive rigid, sandstone units in the main roof or floor. Such conditions encourage severe bumping, roof instability, and occasional floor heave problems.' Various gate road configurations have been employed to alleviate' these problems. Although the mines have comparable basic conditions, the lithologies and qualities of the immediate roof, floor; and seam ate different in each mine and often vary in a single mine. Gate road systems that mitigate hazards in one mine may prove inappropriate in another or for different areas of the same mine. This report relates the geology of the coalfields; describes the location, geologic setting, specific mining conditions, operating history, and the USBM field study and results or conclusions for each mine; summarizes the relative performance of the gate road systems; and emphasizes the need for site-specific geotechnical data to evaluate gate road conditions and performance.

Jan 1, 1994

By K. K. Kelley

Sodium-aluminum and potassium-aluminum silicates are among the more important rock-forming minerals of the earth's crust. They also appear as constituents of some metallurgical slags and of some refractory materials. Consequently, knowledge of their thermodynamic properties is interesting and valuable from several viewpoints. This paper reports experimental determinations of the low-temperature heat capacities and entropies at 298.16° K. of albite, jadeite, and nephelite it the sodium-aluminum silicate series and of adularia, ferriferous orthoclase, leucite and kaliophilite in the potassium-aluminum silicate series. Also high-temperature heat-content and entropy increments about 298.16° K. are reported for albite, jadeite, nephelite, and carnegieite in the sodium-aluminum silicate series. Except for a few high-temperature heat-content values for albite, all these data are available for the first time.

Jan 1, 1953