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By Fred N. Kissell

This handbook describes effective methods for the control of mineral dusts in mines and tunnels. It assumes the reader is familiar with mining. The first chapter deals solely with dust control methods, regardless of the application. It is a brief tutorial on mining dust control and will be of help to the reader whose dust control problem does not conveniently fit any of the mining equipment niches described in later chapters. The subsequent chapters describe dust control methods for different kinds of mines and mining equipment. This includes underground coal and hard-rock mines, as well as surface mines, stone mines, and hard-rock tunnels. Because dust sampling has so many pitfalls, a chapter on methods used to sample dust is included. For those occasions when there is no practical engineering control, a chapter on respirators is also included. Except for those listed as ?future possibilities? in the longwall chapter, the dust control methods described are practical and cost-effective for most mine operators. If controlling dust were a simple matter, dust problems in tunnels and mines would have been eradicated years ago. Unfortunately, most underground dust control methods yield only 25% to 50% reductions in respirable-sized dust. Often, 25% to 50% reductions are not enough to achieve compliance with dust standards. Thus, mine operators must use several methods simultaneously, usually without knowing for sure how well any individual method is working. In fact, given a 25% error in dust sampling and day-to-day variations in dust generation of 50% or more, certainty about which control methods are most effective can be wanting. Nevertheless, over the years, some consensus has emerged on the best dust control practices. This handbook summarizes those practices.

Jan 1, 2003

By James N. Bayne

An examination and analysis of Landsat digital data in the monitoring of surface mines in selected counties of South Carolina.

Jan 1, 1979

By Russell R. Trengrove

The Copper Canyon lead-zinc mine is in the Battle Mountain. District, Lander County, Nev. It was discovered in 1866 and mined for copper until 1935 and for copper and gold until l948, when the main production became lead-zinc ore. The rocks in the area are carboniferous (Pennsylvanian and Mississippian) sedimentaries that have been intruded by quartz monzonite of Mesozoic age. They have been intensely folded, faulted, and tilted. Lead-zinc ore occurs as sulfides disseminated along fractured zones in a conglomerate arid hornfels. Development was carried out by the Bureau of Mines in cooperation with the U. S. Geological Survey and comprised a study of the geology, making maps and. cross sections, and exploring the deposit by diamond drilling from underground. Eighteen holes were drilled, for a total of 2,594 feet. This report contains a brief history of the property and a description of mining methods and beneficiation of the ore, geology, ore deposits and drilling done by the Bureau of Mines. It also contains detailed analyses of the ore samples taken and logs of the holes drilled.

Jan 1, 1951

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 Oliver Bowles

In its geologic sense the term marble is applied to rocks consisting of crystallized grains of calcite or dolomite or a mixture of the two. Although limestone has the same chemical composition as marble it differs in that the component particles of calcium or magnesium car- bonates are granular and noncrystalline. In marble the crystals may be intimately intergrown, whereas limestone is an aggregation of unrelated particles cemented together into a solid mass. In its commercial sense the term marble has a much wider applica- tion. As susceptibility to polish is one of its chief commercial assets, all calcareous rocks capable of polish are classed as marbles. Lime- stones that show little crystalline structure may, if they take a good polish, be classed as marbles. Furthermore, serpentine rocks, even if they contain little calcium or magnesium carbonate, are classed as marbles, as they are commercial substitutes of true marbles.

Jan 1, 1916

By H. C. Miller

The removal of the mud sheaths that are deposited against the faces of productive oil sands during rotary drilling is one of the important problems confronting operators, especially in semidepleted fields where formation pressures are low. Unless the mud sheaths behind the perforated oil strings and, liners are removed and the sands exposed, oil cannot enter the wells. Consequently much oil that otherwise eight be produced from low-pressure sands is trapped and never recovered. Various types of perforation washers, down swabs, and agitators are used at present for breaking down the mud sheaths and. removing the disintegrated clay particles from wells after the perforated pipes have been inserted. Mechanical methods for removing mud sheaths are quite satisfactory, but prompted by tie request of certain operators in the California oil fields Bureau of Mines engineers have conducted a series of laboratory tests with the view of developing a chemical method for removing mud sheaths in oil wells that will be applicable to field conditions.

Jan 1, 1934

By Robert S. Sanford

In April 1948, the Bureau of Mines was requested to evaluate the graphite deposit' known as the Benjamin Franklin and Just mines in Chester County, Pa. After preliminary investigation, it was recommended that the Bureau core-drill, trench, and sample the deposit and make beneficiation tests on the ore. During the first and second World Wars, flake graphite was in short supply, and a number of deposits in the United States were exploited. In 1942, the Defense Plant Corporation, through its lessee, the Benjamin Franklin Graphite Co., purchased 70.263 acres of graphite-bearing land and built a complete mining and milling plant with a capacity of 300 tons of crude ore per 24-hour day at a cost of $426,250 (Plancor No. 1254).

Jan 1, 1949

By C. Özgen Karacan

This study presents the results of core-log analyses from the exploration boreholes, the analyses of face advance rates, and the results of downhole monitoring studies performed in gob gas ventholes for calculation of changes in hydraulic properties in the longwall overburden at a mine site in southwestern (SW) Pennsylvania section of Northern Appalachian Basin. In the ?rst part of the study, coal measure rocks in overburden strata were analyzed and the locations where possible fractures and bedding plane separations would occur were evaluated. In the second part, the hydraulic conductivities were computed by two different slug test analyses methods using the water level changes measured in gob gas ventholes as longwall face approached. Hydraulic conductivities were analyzed with respect to the changes in overburden depth, the locations of the borehole, and mine face advance rates. These data were used to interpret the potential productivities of the gob gas ventholes as a result of fracturing and changes in hydraulic conductivities. The general results showed that the probability of fracturing and bedding plane separations in the overburden increase between strong and weak rock interfaces. Also, the probability of bedding plane separations increases as the interface is close to the extracted coal seam. Evaluation of slug tests showed that the hydraulic conductivity developments in the boreholes and their potential production performances are affected by the underground strata and the roof materials. In situations where the roof material is stiff and thick, the development of high permeability fractures around the borehole will be less. Results also indicated that borehole location with respect to face position affects the fracturing time and permeability evolution as well. Greater overburden depths generally cause earlier fracturing as longwall face approaches, but eventually result in lower hydraulic conductivities and potentially less effective boreholes. Increasing mining rates also resulted in generally lower hydraulic conductivities in the overburden. The results of this study were intended to improve the interpretation of gob gas venthole performance and to provide better siting of these boreholes.

Jan 1, 2009

By Louis R. Iverson

Patterns of species colonization, biochemical interaction among species, and competitive phenomena were studied in four reclaimed areas in western North Dakota ranging in age from one to four years after mining, along with a site from a native mixed grass prairie for comparison. Early successional changes in floristic composition and soil chemistry were quantified. The mined sites had been contoured, topsoiled, fertilized and seeded. Despite seeding of agronomic species, initial colonization was by fugitive species; analysis of the seed bank in topsoil showed that the most dominant colonizers immigrate after topsoiling. Of the 95 species encountered, Kuchia scoparia was the most dominant in the first two years following mining. Kochlo had relatively low densities in the first year (50-80 plants m-2), but was robust and attained heights of 88 cm with a biomass of about 400 g m-2 In the second year, the plant densities increased to over 10,000 plants m"2 but the height and biomass were reduced to 15 cm and 90 g m-2. However, during the third and fourth years Kochia density declined and was practically non-existent by the fourth year, while the planted Agropyron grasses had concomitantly increased. Other pioneers like Amaran thus retroflexus, Chenopodlum album, Helianthus annuus, Salsola spp. And Setaria spp. showed a less abrupt but similar decline. Chemical analysis of the soils over the same time period showed decreases in electrical conductivity (E.C.), and in the concentrations of P, Ca, Mg, Na, Li, Sr, and SO4 (due to leaching), while N increased. Field studies were conducted on the competitive relations between the dominant species - Kochia scoparia and Agropyron spp. - during early succession. It was found the Kochia acted as a "nurse" crop for several months during the first year of Agropyron spp. establishment, but then began to shade heavily by late July, thus reducing grass tillering. Field and growth chamber experiments on the intraspecific competition relations of Kochia demonstrated that its density and dry matter production, per plant and per unit area, conformed to several laws of plant population biology. Autotoxicity or the depression in growth of a species by its own degradation compounds, in Kochia, appears to be the main factor causing the decline in its growth. Results from a field experiment indicated that thinning dense second year Kochia stands to the density of first year stands did not alter the growth of Kochia, providing strong evidence for autotoxicity. Similarly, several growth chamber experiments demonstrated that small amounts of decaying Kochia leaves and especially roots were toxic to Kochia growth, but not Melilotus officinalis or Agropyron canlnum, Chemical analysis of the soils and plant tissues indicated nutritional im¬balances as shown by P/Mn and P/Zn ratios may be responsible for autotoxicity. In addition to Kochia, a bioassay experiment showed allelochemics to be important in several other colonizing species. Although our results indicate that later stage species generally have greater toxicities than first year colonizers, autotoxicity in the very initial stages seems to be accentuated by harsh habitat conditions. Several practices (mowing. fire, etc.) are used to manage grasslands. Mowing of the first year erect, annual, colonizing vegetation was shown to be beneficial in the growth and establishment of wheatgrasses after mining in western North Dakota. Plots containing Kochio predominantly were mowed in mid-and late-July, and in mid-August, during the first year of growth after recontouring, replacing topsoil. seeding and fertilizing. It was found the Kochia densities were reduced to two percent of the control and its biomass reduced to less than one-third when the area was mowed in mid-August. On the other hand, wheatgrasses showed increases of 23% in stem density and 860% in biomass production over the controls when mowed in mid-August. The mowing of Kochia just before seed-set apparently reduces interspecific competition between Kochia and Agropyron spp. during the following growing season. The method is highly recommended for use in hastening the establishment of planted grasses.

Jan 1, 1982

By Lloyd Williams

1. The investigation shows that the Sewanee bed is the only bed of major importance in Marion County, 97 percent of the coal mined in the county having come from this bed. There are coal reserves in minor quantity in the Battle Creek bed, and production from this bed depends on a few small truck mines. The Richland bed, or Lower Sewanee, has been mined in the past, but no coal has been produced from it in late years. There are no production records of any other beds in the county, although same coal has been produced from them. 2. Known measured and indicated reserves in all beds, based on a minimum thickness of 14 inches and on 1,800 tons per acre-foot of coal in place, are estimated to be 61 million short tons as of January 1, 1953. Of this total, 55 million short tons is in beds 28 inches and more thick. Areas in each bed were omitted from the estimate where available data relative to the bed characteristics are too meager to permit 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, 1955

By A. C. Fieldner

The annual reports of the research and technologic investigations conducted by the Bureau of Mines on the occurrence, properties, mining preparation, and uses of coal, of which the present report is the seventh,4/ are intended to be brief summaries of progress. They are guides to the current work and publications of the Bureau but do not replace the more complete reports published by individuals and groups of workers on specific problems. The annual reports present the results of tests, often in advance of publication in other forms, but original contributions in research are reserved for initial publication by their authors. A survey of the accomplishments of the Bureau in research and technologic work on coal during the 5 year period 1935-40 has been made available in the form of a bibliography.5/ This supplements a similar bibliography on this subject that covers the first 25 years of the Bureau, 1910-35.6/

Jan 1, 1943

By Kenneth R. Maser

This report describes a research and development program sponsored by the United State s Bureau of Mines. The purpose of the program was to develop reusable explosion-proof bulkheads for a cross-cut emergency shelter, and to study the implementation of such bulk-heads, and the resulting shelters, as part of an emergency escape plan in a normal coal mining environment. The first part of this report reveals a number of significant conclusions regarding the application of emergency shelters. A study of the cause s of, and the conditions prevailing during a mine emergency indicate s that ideal placement of the shelter s would be midway along developing entries, and at the inter section of butt and main entries. The proper spacing of shelters is based on the travel capability of trapped miners, which is in turn dependent on the height of coal. The life of a given emergency shelter, based on an analysis of the above information, will be anywhere from 6 months to 10 years. Consequently, some shelters are regarded as "temporary?, while others "permanent?.

Jan 1, 1975

By John J. Ginty

The objective of the work reported herein was to evaluate state-of-the-art repeaters used in wireless communications to determine their suitability for use in extending the range of portable and mobile communications in underground mine applications. The scope of the work included wireless repeaters in the frequency range from LF (500 kilohertz) up to the one giga-hertz range. These repeaters included not only single-channel repeaters, that is F1/F1 repeaters for short range simplex party line communications, but in addition, F1/F2 type repeaters currently commercially available in the HF, VHF and UHF bands.

Jan 1, 1975

By Wilmer McInnis

MOLYBDENUM, one of the more versatile alloying elements in modern metallurgy, was first isolated by Hjelm in 1782. The pure metal is silvery white and softer than steel. It melts at a higher temperature than all other metals except rhenium, tungsten, and tantalum. Molybdenum, a member of group V of the periodic table, chemically exhibits valences in stable compounds of 2, 3, 4, 5, and 6. It is a strong carbide-forming element, and much of its alloying effect in steel is imparted through the formation of carbides. Molybdenum occurs in nature only in combination with other elements. The most common occurence is molybdenite (MoS2), which is widely distributed throughout the world; the few known commercial deposits are the major sources of molybdenun1. The other commercially important mineral, wulfenite (PbMo04), was a major source of molybdenum in the United States during the early part of the 20th century, but with exploration and development of the world-famous Climax molybdenite deposit during the World War of 1914-18, molybdenite soon became the world's major source of molybdenum. In recent years, virtually no wulfenite has been mined. Many copper deposits contain minute percentages of molybdenite; and, since the inauguration during the early 1930's of the recovery of molybdenite as a byproduct of these deposits, they have been an important source of molybdenum.

Jan 1, 1957

By R. L. Soderberg

This paper is one of a series on mining methods and costs being published by the Bureau of Mines. It describes briefly the mining methods employed since the start of operations in 1937, with emphasis on the diamond-drill blast-hole method of ore breaking and slusher-drift method of ore drawing at the Holden mine of the Howe Sound Co., Chelan Division, Holden, Wash. The Holden mine is in the north-central part of the Cascade Range, 11 miles up Railroad Creek from Lake Chelan. The nearest railroad is at Chelan Falls, 40 miles by boat and 4 miles by highway from the mine. All freight comes into the mine and all concentrates are shipped out via Chelan Falls. The altitude of the main haulage level is 3,500 feet. Railroad Creek Valley is covered with a dense growth of fir and spruce, while most of the surrounding mountains are rocky, with sparse timber growth.

Jun 1, 1948

By J. H. Wiggins

The evaporation of crude oil without doubt causes one of the largest single losses to which the oil is subjected after it is taken from the ground. The few days during which crude oil is stored on the lease before being taken by the pipe line, causes an aggregate loss per year from evaporation estimated at 122,100,000 gallons of gasoline in the Mid-Continent field alone. This has a value, at 22 cents per gallon, of $26,880,000 and represents about 3 per cent of the total gasoline produced in the United States from all fields and all sources. The following table shows this in more detail:

May 1, 1920

By Charles B. Carpenter

[The Bureau of Mines selected Anahuac for a petroleum-engineering study because it is one of the notable fields of the Gulf Coast region. It is outstanding because the producing formation is very thick; ever modern technique of drilling' and development has been applied; complete records of all operations,, including detailed subsurface information have been kept; the field has ,been developed systematically; and every effort has been made to utilize the reservoir energy efficiently. Data and information pertaining to the development anal operation were collected, compiled, and studied by the writers as if the field were under single ownership. The chief aim of the study was to increase the accuracy of the existing methods of estimating reserves by applying all the data collected during the modern development of an oil field, These scientific aids include coring; electric logging; micropaleontology determinations of porosity, permeability of oil-bearing sands, and their connate water content; subsurface sampling of the reservoir oil; and depth-pressure measurements. Because the reservoir structure in the Anahuac field is extremely complex, special attention was given to methods of calculating the reservoir volume.]

Jan 1, 1941

By W. W. Adams

"The ninth yearly National Safety Competition covering the calendar year 1933, conducted by the United States Bureau of Mines, w participated in by 332 mines and quarries situated in 35 States. Enrollment represented as increase of 10 plants over 1932, and one addition was made to the number of States represented.The primary purpose of the United. States Bureau of Mines in conducting the contest is to promote safety in United States mineral industries. This purpose is accomplished directly through the efforts of the competing companies and their employees to win first place in the competition and thereupon receive recognition on a national scale for their achievement the purpose is accomplished indirectly through studies by the United States Bureau of Mines of the facts contained in the accident reports the competing companies furnish to enable the Bureau to compute the accident rates that are the basis for determining the winners of the contest.The statistics which constitute the basis for determining the winning companies and the relative standing of all companies are prepared uniformly without regard to the States in which the companies operate, or to differences in classes of accidents covered by State laws relating to compensation for injuries resulting, from industrial accidents.Bronze trophies, known as 'Sentinels of Safety', which were provided by The Explosives Engineer magazine to be awarded annually by the Bureau of Mines, were presented to five companies in the contest of 1933, each company having established the best accident-prevention record within one of the five classes into which all companies were divided, namely, anthracite-mining companies, bituminous-coal-mining companies, metal-mining companies, operators of nonmetallic-mineral mines other than coal mines, and quarries or opencut mines. The trophies are awarded for 1 year and are then transferred to the winners of the succeeding year's contest.The trophy for bituincus-coal mines was won by a company in Wyoming. A company in Tennessee won the trophy for metal mining. In the nonmetal-mine group the trophy was again won by a company in New York. A quarry in Michigan won the trophy for the quarry-and-opencut-mine group. The trophy for anthracite mines remains in Pennsylvania, as all anthracite mines in the contest are in that State."

Jul 1, 1934

By H. Leitch

In laboratory experiments, the Bureau of Mines investigated melting, quenching, and sulfuric acid leaching of alumina from mixtures of albite and anorthite, and from anorthosites containing 26 to 32 percent alumina. Variations in pouring temperature, quenching and leaching conditions, were studied with respect to the extraction of alumina and impurities. Virtually all of the alumina was dissolved by leaching melted and quenched California anorthosite in boiling 16-percent sulfuric acid solutions for 15 to 30 minutes. The leach solutions were readily separable from the solid residue by conventional thickening and filtration techniques. Only 2 to 5 grams of SiO2, Fe2O3, or CaO dissolved per 100 grams of alumina. The quantity of SiOz in solution varied inversely with the duration of the leach and with the concentration of the H2SO4 solution used. Melted and quenched Wyoming and Minnesota anorthosites with SiO2:CaO weight ratios of 4.3 and 3.2, respectively, were less amenable to sulfuric acid leaching than California anorthosite with an SiO2:CaO weight ratio of 5.3. However, excellent results were obtained on the Wyoming and Minnesota anorthosites by the addition of SiO2 to these materials before melting, in quantities sufficient to adjust the SiO2:CaO weight ratios of the furnace charges to between 4 and 6.

Jan 1, 1966

By F. E. Harris

The United States produces about 30 percent of the world output of salt. Numerous deposits occur in widely separated areas, but the leading producing States are California, Kansas, Louisiana, Michigan, New York, Ohio, Texas, Utah, and West Virginia. Although no great amount of salt is produced at present in Pennsylvania, the potential sources in that State recently aroused a good deal of interest. The United States salt industry is highly organized; it comprises fewer companies than when small crude works with primitive methods and equipment eked out salt for local needs, but concentration of output brought about by modern inventions and methods of production has improved the quality of the produce greatly and accelerated production.

Jan 1, 1939