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By John W. Kopp

A major concern with blasting at surface mines is generation of ground vibrations and airblast and their effects on nearby residences. This Bureau of Mines report looks at the use of millisecond delays in blast design and their effect on the resulting ground vibrations and airblast. A total of 52 production blasts were instrumented and monitored at a surface coal mine in southern Indiana. Arrays of seismographs were used to gather time histories of vibrations and airblast. The data were analyzed for peak values of vibration and airblast and for frequency con-tent. Various delay intervals were used within and between rows of blastholes. Delay intervals within rows were 17 and 42 ms, and those between rows ranged from 30 to 100 msj these intervals are equivalent to 0.5 and 1.3 ms/ft within rows and 1.2 to 4.3 ms/ft between rows. Sub-sonic delay intervals within rows reduced airblast by 6 dB. Large delay intervals between rows reduced the amplitude of ground vibrations; their frequency depended primarily upon the geology of the mine site.

Jan 1, 1986

By Manuel Gomez

This report presents prediction equations for 12 variables that are indicative of metallurgical coal quality. The variables include six for coke strength and six for carbonization product yields. All variables were predicted for coking coals having volatile matter contents from 16.3 to 42.1 percent, dry basis. The prediction equations, developed by mathematical-statistical techniques, were based on information from the proximate and ultimate analyses, the size consist, and the petrographic composition of bituminous coals carbonized in BM-AGA retorts at 800°, 900°, and 1,000° C. The equations were evaluated for validity with independent data derived from the 900° C carbonization of 33 binary blends of various coals and 22 binary blends of Pocahontas No. 3 low-volatile bituminous coal with 11 high-volatile bituminous coals. Results show that metallurgical coal quality can be predicted ahead of mining because data used to derive the prediction equations can be obtained at the time of exploration. Capability to forecast coal quality is useful in mine planning and should provide basic information for optimization of blending and crushing techniques and thus lead to the production of uniform coke.

Jan 1, 1970

By By Staff

"Acid mine drainage can be controlled by water treatment, retardation of the pyrite oxidation reaction system, or enhanced prediction that allows preventive action to be taken. The Bureau of Mines is conducting research in each of these areas; the results of this research are summarized in the eight papers that comprise this volume. Field work to evaluate overburden analysis, alkaline injection, and bactericidal control of acid formation is described, along with two new inexpensive methods to treat acid mine water. These papers were prepared for an acid mine drainage technology transfer meeting held in Pittsburgh, PA, on April 3 and 4, 1985. INTRODUCTIONAcid drainage from coal mines is one of the most persistent industrial pollution problems in the United States. Over 5,000 miles of streams and rivers are adversely affected, primarily by underground mines that have been abandoned for decades. Meanwhile, at active mining operations and at sites where mining occurred after 1977, discharge water must be treated to meet fairly stringent regulatory limits--at a cost to the industry of over $1 million per day.The Bureau of Mines has a special responsibility to facilitate integration of mining and mineral processing with environmental safeguards. This responsibility is twofold: the development of techniques to reduce or eliminate environmental degradation, and the improvement of existing pollution control processes to make them more efficient and more cost effective. Research in acid mine drainage exemplifies the Bureau's concern for these environmental aspects of mining.This collection of papers summarizes much of the Bureau's recent research on acid mine drainage and will give the reader a sense of where the research is headed, in addition to providing details regarding new technology and recently acquired knowledge. The research papers address four basic objectives:"

Jan 1, 1985

By Cecil Q. Cupps

Results are presented of a comprehensive study of the characteristics of the original oil in the Weber sandstone reservoir, Rangely oil field, Colorado. Through the medium of subsurface sampling, adequately representative samples of the original reservoir oil were obtained from many parts of the reservoir over a period of 5 years concurrent with active development of the reservoir. Data of differential gas liberation, pressure-viscosity, and. pressure-volume-temperature relationships are shown for 12 subsurface oil samples. Data also are given of reservoir pressure and. temperature, composition of liberated or solution Gas, composition of 22 produced-gas samples, and Hempel analyses of crude-oil samples from 18 wells. The characteristics or physical properties of the 12 subsurface oil samples, as determined by laboratory analyses, were correlated with elevation of the top of the Weber sandstone. These relationships of oil characteristics to elevation in the reservoir show that only the oil in contact with the initial gas cap was gas-saturated at the existing pressure and temperature. The characteristics of the original reservoir oil were marked by an appreciable decrease of saturation pressure and solution gas-oil ratio and increase of viscosity and density with depth below the gas-oil contact. The composition of solution gas and of' produced was also was found to vary with elevation of the oil in the reservoir.

Jan 1, 1951

Data recently released indicate substantial improvement in mineral industry performance for 1984. Business plans to increase plant and equipment spending in 1984 by 14.8 percent, according to a recent survey conducted by the Commerce Department's Bureau of Economic Analysis (table 1). In contrast, capital spending by all industries declined 4.8 percent in 1983 and 2.3 percent in 1982. The latest estimate of planned expenditures for 1984 is $2.2 billion higher than the comparable estimate based on the survey conducted in late January and February 1984.1/ [ ] Of particular significance to the U.S. mineral industries are the 15.5-percent increase in capital spending planned by manufacturing in 1984 and the planned 18.6-percent increase in spending by durable goods manufacturing, where the largest increases are planned in the transportation equipment (26.4 percent) and electrical machinery sectors (23.5 percent). Capital expenditures in manufacturing declined in both 1982 and 1983.

Jan 1, 1984

By John W. Sweeney

Shales and clays from Illinois were sampled, tested, and evaluated to determine feasibility of producing lightweight aggregate by rotary-kiln methods. Sampling procedures and the 1 ,,,y of the Pennsylvanian shale units are discussed. Chemical, X-ray spectrographic and X-ray petrographic analyses were run on the samples to determine if a correlation existed between chemical mineralogic composition and expansion. Preliminary expansion testing was conducted in a muffle furnace. Rotary-kiln tests were conducted in a 16- inch by 14-foot rotary kiln. The weight of the aggregate ranged from 27 to 59 pounds per cubic foot. Concrete cubes employing the aggregate were tested to determine the qualities of the concrete. Compressive strength of the concrete using the 7-bag of cement cement per cubic yard mix, after autoclave curing for 6 hours, ranged from 2,950 to 6,750 psi. No correlation was found between the chemical, X-ray spectrographic, and X-ray and petrographic analyses and expansion, Sixteen samples made suitable lightweight aggregates in the laboratory rotary kiln. The expansion temperature range of eight of the samples was extremely narrow, and difficulties would probably be encountered in processing these materials commercially.

Jan 1, 1965

By S. M. Runke

The purpose of the work described in this publication was to determine, on a pilot-plant scale, the practicability of concentrating low-grade bauxite deposits to render them suitable for the extraction of alumina. In 1941, when it became apparent that the United States might soon be drawn into war, the government, through its various agencies and bureaus, began to stimulate and increase production from domestic reserves of bauxite, which is the principal raw material for the production of aluminum. This activity, which was centered in Arkansas, where 95 percent of the domestic reserve is situated, reached peak production when enemy submarine warfare greatly hindered imports from foreign sources. During this period the average domestic production in Arkansas rose from approximately 300,000 long wet tons to something over 6,000,000 tons in 1943.

Jan 1, 1949

By Lars Skogsberg

Work with hand-held power tools can be found in most industries all over the world. This type of work exposes the operators to different kind of loads like gripping-forces, feed-forces, exposure to vibration and noise, holding hot or cold surfaces and the exposure to dust. Designing a power tool with good ergonomics is a matter of finding the best compromise. As a simple example, increasing the mass is not acceptable because it will increase the forces needed to handle the tool. At the same time increased mass will in most cases reduce the vibrations. Vibration disorders related to the use of hand-held power tools has been known and reported since long. It is therefore essential that low vibrating tools are developed and used. The new vibration regulations in Europe, based on the Physical Agents (Vibration) Directive, have put increased focus on the vibration control in industry. Forces acting on the tool cause vibration Tools for industrial use must be of very robust design to withstand the very hard use they are exposed to. Industrial tools are therefore normally designed with the main parts made of metal. From a vibration point of view this means that most tools can be regarded as rigid bodies, especially because the dominating frequency normally is equal to the rotational frequency of the tool spindle or the blow frequency for a percussive tool. These frequencies are with few exceptions below 200 Hz. Handles however can not always be regarded as rigidly connected to the tool. There are several examples of weak suspensions designed to reduce vibration transmitted to the hands of the operator. There are also examples of designs where the handles just happened to be non-rigidly connected and in some cases even in resonance within the frequency region of interest. Oscillating forces act on the tool and the result is vibration. Design principals In all cases forces are the source of vibration. This leads to the three basic principles to control vibration: • Control the magnitude of the vibrating forces. Examples are the balancing unit on a grinder or the differential piston in a chipping hammer. • Make the tool less sensitive to the vibrating forces. Examples can be when the mass of the guard on a grinder is rigidly connected to the tool to increase the inertia of the tool. • Isolate the vibrations in the tool from the grip surfaces. Examples are vibration-dampening handles on grinders or pavement breakers, the air-spring behind the blow-mechanism in a riveting hammer or the mass spring system in a chipping hammer.

Jan 6, 2006

By R. V. Ramani

This volume is the fourth of a four-volume final report on research carried out under a contract from the U.S. Bureau of Mines on the development of a computer simulation model for surface mine reclamation planning. The other volumes are titled as follows: Volume I: Ore Reserve Estimation, Volume II: Dragline Model, and Volume III: Mine Coordinate Generator System. The Open Pit Materials Handling Simulator (OPMHS) was first developed" in 1971 and modified and updated in 1975. The present work is an update of the 1975 version and provides a direct link between the geology and reserves system and the various activities of the mining equipment in a mining system. Also, the modeling techniques in OPMHS/2 have incorporated a flexible method for describing various equipment (shovels, trucks, belts, trains, etc.), locations, their sequence of operations, place changes, and their interactions. These features allow for studying mining equipment selection, mining method analysis and reclamation planning. This report describes the Open Pit Materials Handling Simulator Version 2 (OPMHS/2). The report details the program features, operation, and application. Through an extensive set of appendices, the data input sequence, input variable definitions, sample data listing and program output are presented in detail.

Jan 1, 1985

By D. W. Dareing

Multiple branch wellbores and horizontal holes, when applied to deep lying ore bodies, have the potential of significantly reducing well costs by reducing total footage drilled per acre of well pattern. In addition, horizontal holes may increase sweep efficiency. Well completion is a major problem. They must be cased to contain leaching solutions within the underground portion of the production loop. Several drilling and completion concepts are given and evaluated in the report. Our evaluation shows that there is economic incentive to further develop these concepts for field application to ore bodies 1,500 feet. Multiple branch concepts are the most attractive. They can reduce well costs by as much as 30° when applied to 2,000 feet ore body depths (44%, at 5,000 feet) and can accommodate a lamer pump than conventional vertical wells. We recommend this concept be developed further to accommodate either dual or triple branches.

Jan 1, 1980

By D. Harrington

When the word "gas"' is mentioned in connection with mining almost invariably it is inferred that the explosive gas, methane, is in mind and that the reference is to coal mining. Although methane is likely to occur in any coal mine the metal mines of the world contain by far a greater variety of gases than do the coal mines. Often the gases in metal mines are as dangerous as the gases likely to be found in coal mines, and sometimes are even more deadly. A coal mine is more likely to contain methane than a metal mine. In rare instances it may contain high percentages of nitrogen or carbon dioxide or it may be deficient in oxygen where the air is confined in a blind end or in a sealed region. Much more rarely relatively small percentages of ethane or other hydrocarbons with an odor of ether, gasoline, or kerosene, or minute percentages of hydrogen sulphide are found in a coal mine. During a coal-mine fire or explosion carbon monoxide content is likely to be high (4 per cent or more), and if the coal contains much sulphur the high fumes may contain some sulphur dioxide.

Jan 1, 1931

The Mine Safety and Health Administration (MSHA) defines an independent contractor as any person, partnership, corporation, subsidiary of a corporation, firm, association or other organization that contracts to perform services or construction at a mine. Contractors that perform specific types of work are required to report the number of employees who work at coal mines and noncoal mines.

Jan 1, 2008

By J. W. Thompson

RIGHT OF LIFE TENAN1' TO OPEN MINES. The common-law rule that a life tenant was not permitted to open or share in mines does not prevail in Michigan; but a life tenant by dower right is permitted to share in the royalties, as the strict common- law rule is not in harmony with the spirit of our institutions and the policy of our law and would often result in defeating the purposes of dower statutes. Poole v. Union Trust Co. (Michigan), 157 Northwestern 430, p. 432, March, 1916. SALE AND CONVEYANCE. PURCHASE OF ENTIRE ESTATE--FRAUD. A purchase of land where no exceptions or reservations of minerals were made and the land was bought as property, when nothing is excepted and no qualifications or reservations are embodied in the agreement, was presumptively and by common understanding a purchase of the property in its entirety; and the insertion in the deed of a reservation of mineral rights in violation of the contract of purchase and without the grantee's knowledge or consent was fraudulent. Mtynarczyk v Zyskowski (Michigan), 157 Northwestern 566, p. 569, March, 1916. RESERVATION OF MINERALS--EXTENT AND EFFECL A reservation in a conveyance of land excepting and reserving to the grantor all coals and mines beneath the surface with the sole right and privilege to remove the same, is not as broad as the grant itself. A contract for the purchase of a mine recited that a deed had been executed by the owner and placed in escrow to so remain until the sum of $30,000 should be paid. The contract provided that $1,200 of the purchase price was to be paid in cash, $800 in 60 days, and the remainder out of 20 per cent of the gross output of the mine, such per cent to be paid in five years unless the vein and value of ore should not continue in depth, in which event the purchaser was to have two years longer to complete the payment of the purchase price. The contract contained other covenants to the effect that the purchasing corporation would fit up a certain specified mill and would continue development work at such rate as to keep the mill in operation if ores sufficiently valuable should be found and in the absence of unavoidable accident. The contract also provided 1/ that abandonment of work for a period of six months at anyone time, except as above, on said property," should operate as a forfeiture of the purchaser's right. In an action by the vendor to quiet the title to the land and to have the contract declared void, the court found that the purchaser failed to perform the work on the property and failed to place thereon the improvements as required by the contract and permitted debts to accumulate against the property, taxes to be levied thereon, and that for more than a year the purchaser had not done any work or labor of any sort upon the mine or premises, and that the contract contemplated development work from the time the purchaser took possession of the property, or at least promptly thereafter, and the fact that no machinery was in place for a year or more after the execution of the contract was a breach of the covenant of continued development, and that the clause in the contract" except as above" does not contemplate a delay in the development resulting from a failure to install machinery, but it means that unless prevented by unavoidable accidents the purchaser shouLdhave no valid excuses for neglecting the work for a period of six months or more.

Jan 1, 1917

In 2006, a total of 4,573 stone mining operations reported employment to the Mine Safety and Health Administration (MSHA).1 Stone mines comprised 30.7% of all mining operations. ? Mines producing the primary commodity of limestone (crushed and broken) comprised the largest number of operations (n=2,042; 44.7%). ? Stone mining operations were located in all states and territories except Delaware and North Dakota. ? Pennsylvania had the most stone mines (n=368; 8.0%), followed by Texas (n=342; 7.5%).

Jan 1, 2008

By H. E. Hilliard

A method was investigated for detecting and counting filamentous iron bacteria in open recirculating cooling systems. It is simple and fast and does not require trained microbiologists. Samples from 26 systems were examined. Cells were cultivated on commercially prepared ready-to-use media. Cultures grew well on this medium and were identified as filamentous iron bacteria by microscopic examination and by their ability to deposit iron using the prussian blue reaction.

Jan 1, 1976

The 53 countries that constituted Africa in 1993 accounted for a significant portion of total world output of a number of mineral commodities. For the continent as a whole, world shares of most commodities showed little change from those of 1992 although most output volumes showed a slight decline. There were no significant production increases, but there were significant decreases of cobalt and copper because of political instability in Zaire and production problems in Zambia, of chromite resulting from cutbacks in South Africa and Zimbabwe, and of phosphate rock owing to a lower output by producers in general. (See tables 1 and 2.) Among the most significant mineral commodities produced in Africa, ranked by portion of world production in 1993, were diamond, cobalt, chromite, gold, phosphate rock, manganese ore, uranium and petroleum. Others of importance in world trade were andalusite, antimony, asbestos, bauxite, coal, copper, fluorspar, lithium minerals, platinum-group metals (PGM), titanium minerals (ilmenite and rutile), vanadium, vermiculite, and zircon. Several of these-chromite cobalt, diamond, and manganese-were not produced in the United States.

Jan 1, 1995

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 R. Michael Digman

Few efforts have been undertaken to date to assess the quality of mandated coal mine health and safety training for new miners and for experienced miners. This study was concerned with the quality and effectiveness of existing classroom health and safety training programs. The study involved field data collection through pre- and posttesting of trainees, audio-taping class sessions, and administering short feedback forms with trainers and trainees at 14 sites in West Virginia, Maryland, Kentucky, and Pennsylvania. Results indicate that goals, methods, materials, and outcomes of existing training programs vary widely among trainers and sites. The report provides less by way of solution to problems, than it highlights the breadth of issues that relate to the question of training effectiveness and quality. The report concludes that additional work by industry, labor, government, and academia is necessary in order to improve health and safety training programs. Recommended steps are: (a) to develop performance standards and measurable criteria in each of the types of mandated training, (b) to develop better training of trainers, (c) to develop expanded training support services. and (d) to undertake further research and development in health and safety training in the mining industry

Jan 1, 1982

By F. S. Crawford

The wide variation in the medical facilities, type of accident reports and provision for the welfare of employees, in addition to the compensation provided by the various State laws,- was -studi-eci, by the.. wri-ter in the Lake .. Superior_ r.egion . .. - -Several cDmpanies f~rnished. the information which follows. Names have been omitted , ~ut the information should be of .intere·st to companies desirous of improving t_his branch of thej..r accident-prevention work. : . . --Because a summary of the metho.ds used would merel:y: result in _ a.n a.ttempt to set _up an ideal, it was concluded that in preparing this paper a statem.ent .of_ tbe individual methods of -each company wou-l d .b-e .Qf .. the most inte-res.t, . and the.y h~ve . been .. li.steq with .no regard to the size of the company . . ··· -In the - appendix are -a -number of report. forms used by .various _operators for reporting accidents to t he company and .to the State. These are self- explanatory. and many a re mentioned in -the body of circu-1-ar-.

Mar 1, 1932

By Grant R. Brown

The report provides guidance for determining those environmental impacts associated with the surface mining of steeply pitching coal seams. In addition to the environmental impacts, four additional issues are addressed, namely (1) Time and motion studies of those coal mining systems employed in mining seams which pitch in excess of 25°, (2) Assessment of those mining techniques, (3) Development of rationale for the mining methods employed, (4) Identification of the reclamation practices and determine whether these practices were in compliance with appropriate Federal and State regulations. Five surface mines located in three geologically distinct basins of the United States were analyzed during the period of August through November 1979. The three basins include the Hanna Basin of Wyoming, the North Park Basin of Colorado and the Southern Anthracite Field of Pennsylvania.

Jan 1, 1980