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By Alden H. Emery, J. J. Forbes

"IntroductionThe data contained in this paper were collected during the course of an investigation which covered 15 representative coal mines in 6 coal-mining States. The purpose of the investigation was to determine by atmospheric sampling how much dust was raised into the air during the various operations of coal mining, such as undercutting with machines, loading coal by hand, and transporting it from the working face to the surface. The data thus obtained were considered from two angles - namely, the possible physiological effect of inhalation and the explosion hazard of the dust. No attempt will be mode to discuss the former factor in this paper.CONDITIONS OF MININGThe mines in which this investigation was conducted were considered representative, and it is believed that the results obtained will suffice for the average dustiness encountered in most coal mines. .All of the coal mined was bituminous, from beds 30 to 120 inches thick. Only the ordinary room-and-pillar system of mining was employed. Daily production ranged from approximately 700 to 1500 tons and the men employed from 150 to 450. Coal was undercut by short-wall mining machines in all mines, with the exception of one in which pick mining was employed. Loading at the face was done by miners; none of the mines used mechanical loaders. Electric drills, both for brushing roof and for shooting coal, were commonly used although some roof work was done with jack-hammers and a. little of both with augers. Coal was hauled by motor, mule, or rope power in end-gate cars with capacities ranging from 1600 to 3600 pounds. With few exceptions, coal was won at the face by dry methods - that is to say, no water was employed fox wetting down the dust either during undercutting, loading, or transportation."

Feb 1, 1927

By Jorge Soto

Las plantas de tratamiento ubicadas en Nazca-Ica y Chala-Caravelí, Arequipa en el sur del Perú, utilizan sistemas de almacenamiento de relaves convencional donde los riesgos de ruptura y contaminación están latentes en la operación. Estas plantas están bajo la fiscalización de los entes reguladores (OEFA, OSINERGMIN, ALA), comunidades, población, ambientalistas, accionistas y gerentes de compañías quienes se ven con necesidades inmediatas de invertir altos presupuestos con la finalidad de mitigar los riesgos físicos, químicos y ambientales derivados de dichas soluciones convencionales.

Sep 1, 2017

By Keith D. Rosbury

The basic objective of this project was to determine the cost-effectiveness of dust control used on unpaved mine haul roads. Field testing was conducted at three surface coal mines (two in Wyoming, one in southern Illinois) for a total of 20 weeks. The highest control efficiency measured for a chemical dust suppressant, 82 percent, was for calcium chloride two weeks after application. Generally, however, the control efficiencies hovered in the 40 to 60 percent range over the first two weeks since application, and then decreased with time. After the fifth week, the limited number of data points suggest a control efficiency of less than 20 percent. Composite watering data were fairly uniform. Watering once per hour resulted in a TSP control efficiency of approximately 40 percent. Doubling that application rate increased the control effectiveness by about 15 percent to 55 percent. Chemical dust suppressants (primarily salts and lignons) can be shown to be more cost-effective than watering under some conditions. Data summaries and the analysis of data are contained in Volume I. Volume II contains basic data.

Jan 1, 1983

This report presents depth and producing rate statistics pertaining to oil reservoirs (or fields) in each of the 14 States that produced more than 20 million bbl of oil during 1965. The combined oil production was about 2.6 billion bbl, or 96 pct of the U.S. total. Data are presented for each of the 14 States, each Texas Railroad Commission district, and four geographical areas of Louisiana. About 8 pct of the total oil produced in the 14 States was from depths of lees than 2,000 ft, 24 pct from 2,000 to 4,000 ft, 22 pct from 4,000 to 6,000 ft, 16 pct from 6,000 to 8,000 ft, and 30 pct from 8,000 ft and deeper. The average production per well in the 14 States ranged from 4.4 bopd for wells less than 2,000 ft deep to 57.6 bopd for wells 8,000 it and deeper. Data indicate that 9.5 pct of the 460,968 wells produced more than 1.2 billion bbl or 46.6 pct of the total oil. Oil production from reservoirs (or fields) not undergoing stimulative recovery operations, such as steam, air, gas, or water injection, wee about 1.1 billion bbl or 42.1 pct of the total.

Jan 1, 1967

In 2005, a total of 739 nonmetal mining operations reported employment to the Mine Safety and Health Administration (MSHA). These mines (e.g., potash, gypsum, salt) comprised 5.0% of all operations. ? Mines producing common clay comprised 26.9% (n=199) of all nonmetal mining operations. ? Nonmetal mining operations were located in all states and territories except Alaska, Delaware, Hawaii, Maine, New Hampshire, Rhode Island, Puerto Rico, and the Virgin Islands.

Jan 1, 2008

By H. F. Moore

DURING the last six years, there have been many extensive investigations of the fatigue of metals. The major work of 'these investigations has been the determination of constants for fatigue strength of wrought ferrous metals; but during the past year or two there have become available considerable test data on the fatigue strength of certain nonrferrous metals, including copper, brass, bronze, nickel, copper-nickel alloys, aluminum and aluminum alloys, magnesium and magnesium alloys. It is not proposed to give here extensive quantitative tables of test results; for such tables, reference is made to the published data of various laboratories. The following general conclusions, however, seem to be fairly well established: 1. The phenomenon known as "fatigue" of metal really a progressive fracture of metals. A minute (probably submicroscopic) crack is formed in the metal, the internat stress, is intensified at the ends' of the crack, and under successive applications of load the crack spreads like a minute hacksaw cut until there is not enough sound metal left in the cross-section of the piece to stand the load. applied, and then failure occurs suddenly. 2. For wrought ferrous metals, there is .a limiting intensity of stress (as computed by the ordinary formulas of mechanics of materials) below which, a metal is able to withstand an indefinitely large number of repetitions of stress without failure. This limiting stress is known as the "endurance limit or the fatigue limit.? For reversed flexure, the endurance limit for. wrought ferrous metals is usually not far from 50 per cent. of the ultimate tensile strength.

Jan 1, 1925

By Maurice Deul

This bulletin summarizes the work conducted under the Bureau of Mines methane control research program during the years 1964 to 1979. This research effort was directed toward improving existing methods and developing alternative methods of reducing the explosion hazard during mining. The research was performed in three general areas: (1) basic factors that control the emission of methane into coal mines, (2) methane control during mining, and (3) methane drainage in advance of mining. Topics discussed in this bulletin include the magnitude of the methane problem; the equipment and instruments developed; the geological, chemical and physical parameters that control the movement of methane in coalbeds; the direct method of determining gas content; the estimates of gas content from adsorption data; and methane drainage, through shafts, through horizontal boreholes, through vertical boreholes, or through slant holes. Improvements in ventilation, control of methane in gob areas, and water infusion are also discussed, as is the potential use of coalbed methane as a supplement to natural gas supplies. This bulletin provides a comprehensive source of information on the accomplishments of the Bureau's methane control research program, on the technology developed, and on the direction of further research.

Jan 1, 1986

By A. Newman, A. Brickey

A pesar de que parte del predominio de software de programación de producción a cielo abierto se puede explicar por la preponderancia de la minería a cielo abierto en todo el mundo, hay otros factores que han dado lugar a un retraso en el software subterráneo correspondiente. Explicamos por qué matemáticamente la programación de la producción subterránea es más difícil que su contraparte a cielo abierto y daremos pautas para la investigación en el campo de la programación subterránea.

Jan 1, 2014

By H. L. Lovall

Huge banks of preparation plant refuse and other non¬saleable materials have accumulated over the years in all major United States coal producing areas. These banks, esthetically and commercially undesirable, can cause air and water pollution and land reclamation and mineral conservation problems for the industry and nearby communities Although some refuse banks have been reworked to recover saleable coal, all remain and accumulation continues. Even those previously processed continue as potential hazards. Among the several problems created by refuse banks, in situ combustion is most treacherous. Of the millions of tons of major accumulations, there are at least 450 refuse banks on, fire at this time Attempts to extinguish such fires are costly, impractical and generally unfruitful. Studies are in progress to evaluate the potential of processing such materials to eliminate the combustion capability and to yield usable fuel and nonfuel products. Aspects of the study now in. development for coal refuse include: (a) evaluation of characteristics (size, sink-float, ash, sulfur and calorific value) of the coal refuse materials which are known to be highly variable, (b) development of an ignition test having significance for in situ conditions, (c) study of processing capabilities (comminution for liberation, pilot plant washing tests), and (d) investigation of potentially significant properties of fuel and nonfuel products which could be altered to enhance their market potential.. Among the latter products are lightweight aggregate, fill for mine slushing operations, construction, etc: Plans are to extend the studies to include the design, erection, and test processing of refuse with a transportable plant,; which could provide basic economic and product utilization data from several locations

Jan 1, 1964

By H Chen

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. The Mesozoic iron oxide-copper-gold (IOCG) mineralisation in southern Perú and the northern Chile coastal IOCG belt have emerged as two of the major exploration targets in the Central Andes in the last two decades. These Mesozoic Andean IOCG deposits formed in two mineralisation epochs, the Middle-Late Jurassic (170–150 Ma) and Early Cretaceous (130–110 Ma), with the major Cu-rich IOCG deposits located in the Early Cretaceous mineralisation belt. The early studies in some IOCG centres support a magmtic-hydrothermal model for both Cu-rich IOCG deposits and broadly contemporaneous Cu-poor ‘Kiruna-type’ magnetite deposits. However, recent evidence from field, geochronology, fluid inclusions and stable isotopes show that in the major Central Andean deposits (eg Raúl-Condestable, Mina Justa in southern Perú, La Candelaria-Punta del Cobre and Mantoverde in northern Chile), the incursion of evaporite-sourced basinal brines or sea water may be a prerequisite for economic Cu mineralisation. Moreover, the Cu-poor massive magnetite deposits could be interpreted as a product from iron oxide melt, with minimal intervention by non-magmatic fluids. Therefore, they could represent two contrasted deposit types and contain little genetic relationships. The different roles of magmatism during the Mesozoic are responsible for the variable mineralisation in the Central Andes, including IOCG, magnetite and ‘manto-type’ deposits. The ore modelling for both the Middle-Late Jurassic and Early Cretaceous metallogenic epochs in the Central Andes are reconstructed.CITATION:Chen, H, 2015. The Mesozoic iron oxide-copper-gold (IOCG) mineralisation in the Central Andes – a refined IOCG ore-forming model in the Palaeozoic Continental Margin, in Proceedings PACRIM 2015 Congress, pp 251–254 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By R. F. Kehrman

Voice Frequency (VF) electromagnetic trapped miner location devices were tested for reliability and effectiveness in 93 coal mines. Tests included uplink pulsed CW, downlink pulsed OW and downlink voice evaluations. Frequencies were 630, 1050, 1950 and 3030 Hertz. Overburden depths varied from 70 feet to 1550 feet. Successful communications were established at 91 of the 93 mines. Data indicate the transmitters and receivers will operate in practically all coal mine environments. Reliability and accuracy as location devices appear to depend on noise, depth and presence of metallic objects which distort the magnetic field. In addition, theoretical models appear to define best case situations in terms of noise and conductivity. Minor hardware problems were encountered, mostly involving battery contacts, switches and antenna cables on the receivers. No hardware problems occurred with the transmitters.

Jan 1, 1978

By Robert T. Davis

An award is a form of recognition given for superior performance in a special field of endeavor. Each year awards are given by the Joseph A. Holmes Safety Association and the National Safety Council to the coal-mining industry's underground and open-pit mines that have worked a specific number of man-hours without a lost-time injury. These awards have a dual significance in that they prove efficiency can be attained without injury to persons. Safety awards do not result from luck or good fortune but do result from sincere desire coupled with sufficient effort and cooperation to achieve a desired goal.

Jan 1, 1964

By S Arai

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. Podiform chromitites are commonly found in the Moho transition zone to the mantle section of ophiolites, but have been very rarely found from the current ocean floor, even though some ophiolites are considered as a slice of oceanic lithosphere. One of the factors controlling podiform chromitite formation is the chemistry of host mantle peridotite; an intermediately refractory harzburgite is the optimum host for chromitites. This harzburgite represents the most common lithology of the oceanic lithosphere, where the peridotite-melt reaction, which is another condition, is possibly common there. The oceanic lithosphere mantle is thus a good host for podiform chromitites. The apparent rarity of documented oceanic chromitites is solely due to under-sampling of mantle materials from the fast-spreading ridge and the segment centre of slow-spreading ridges. Some ophiolitic chromitites formed not from genuine mid-ocean-ridge basalt (MORB) but from wet MORB due to the situation of typical ophiolites, which formed not at ordinary mid-ocean ridges but at supra-subduction zone spreading centres.CITATION:Arai, S, 2015. Podiform chromitites do form beneath mid-ocean ridges , in Proceedings PACRIM 2015 Congress, pp 465–468 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By Donald J. Frendzel

The post-World War II expansion of the Soviet petroleum industry has established the U.S.S.R. as a major oil-producing nation and has led to Russian reentry into the international petroleum trade. The rapid growth of Soviet petroleum production will allow the U.S.S.R. to displace Venezuela as the world's second largest oil-producer in 1960 and to narrow further the gap between Soviet and U.S. crude-oil production. U.S.S.R. crude oil output was only a tenth of U.S. production in 1946, but it will be more than a third at the end of 1960 and more than half in 1965. The Soviet Seven-Year Plan (1959-65) for oil provides for substantial increases in petroleum production, refining, storage, and distribution facilities. Crude oil production and primary distillation capacity are to double, considerable storage capacity is planned, and pipelines for crude oil and petroleum products are to increase threefold. According to the Soviets, the initial phases of this plan (1959 and 1960) have been completed successfully. However, this progress has been achieved with difficulty.

Jan 1, 1961

By William G. Fischer

This paper attempts to close the gap between extensive rock testing with field measurements and the mine operator's need for safe mine layouts and alternatives. It was found that many of the variables that influence mine geometry and worker safety are relatively unimportant while others are critical. The development of empirical relationships which tie the critical variables to the "safe useful life" of a trona mine layout and observations made in 140 production areas where the variables were researched over a fifteen year period are discussed. The concepts presented may have applicability in mine design for other bedded deposits.

Jan 1, 1984

By Horace C. Porter, F. K. OVITZ

The various fuel investigations that were being carried on by the technologic branch of the United States Geological Survey were transferred by law on July 1, 1910, to a new federal bureau, the Bureau of Mines, that was authorized to continue the investigations and make public reports of the results. In consequence of this transfer, the following report is published as a bulletin of the new bureau. The United States Geological Survey had been engaged in analyzing and testing coals, lignites, and other mineral fuel substances under authority given by act of Congress. This work, now centered at the experiment station at Pittsburg, Pa., had its beginning in the operations of the coal-testing plant erected at the Louisiana Purchase Exposition in St. Louis, Mo., in 1904. The results obtained at that plant showed that the work of determining the fuel value of the coals and lignites in the United States with a view to increasing efficiency in their utilization would be incomplete if it did not include systematic physical and chemical researches into the processes of combustion. Hence in its later investigations the Survey carried on such re- searches, concentrating attention on those lines of inquiry which promised results of greatest economic importance. This bulletin is a report on an investigation of the volatile matter in several typical coals-its composition and amount at different tem- peratures of volatilization. As the investigation is still in progress and will doubtless include other coals than those already examined, the bulletin may be considered a preliminary report, stating the prob- lems studied, the methods used, and the results thus far obtained.

Jan 1, 1910

By C. C. Blade

"This report on the properties of motor fuels sold through service stations ni the Unietd States is a continuation of a series of reports made in accordance with a cooperating agreement between the Coordinating Fuel Research (CRF) Committee of the Coordinating Research Council (CRC)3/ and the Bureau of Mines of the United States Department of the Interior. The first of these reports presented data on motor gasolines sold during the winter of 1935-36.4/ Further reports were issued describing motor gasolines sold during the succeeding summers and winters to and including the summer of 1941.4/ No reports were made on motor gasolines sold during the winter of 1941-42 and during the summer of 1942. However, starting with the winter of 1942-43, the semiannual reports were resumed.4/The present report presents analytical data for 1,381 samples, representing the products of approximately 75 companies. Most of the samples represented in this report were secured during July and the first half of August, 1945. As in previous surveys, the companies covered by the survey include both large and small suppliers. Conforming to former reports, the data cover three groups of samples – regular-price, premium-price, and third-grade gasolines.As the number of analyses submitted for samples of third-grade gasoline are not considered adequate to represent this type of motor fuel, data for the analyses have not been averaged, but the individual items are tabulated. The number of samples, items and brands comprising each group is as follows: Regular-price, 733 samples, 229 items, and 57 brands; premium-price, 504 samples, 197 items, and 56 brands; third-grade, 84 samples, 28 items and 12 brands. The meanings of these terms as sued in the surveys are as follows:"

Jan 1, 1946

By Jaime Mercado

"El presente texto señala los yacimientos de cobre de tamaño medio, que por su especial ubicación geográfica son de importancia regional y nacional su desarrollo. Dichos yacimientos están ubicados en la faja costera de Arequipa (Condestable, Raúl, Río Seco, Monterrosas, Acarí y Chapi) y Lima. Además de estos yacimientos, existen otros, cuyas reservas y potencial no están determinados. Sus principales características son: proximidad a la carretera Panamericana, puntos de embarque de primera importancia, depósitos de almacenamiento de ácido sulfúrico, energía eléctrica del Mantaro y Charcani en proceso de ejecución. "

Mar 1, 1982

By Jacob W. Young

A casual reading of the geological literature extant to-day would give one the impression that carbon is an element which by some chance or another always existed at or near the surface of the earth, and was never of a magmatic origin. The carbonaceous matter in shales is said to be of vegetal derivation; petroleum is stated to have been derived from vegetable matter or from marine animal bodies; if carbon or bituminous matter is found in igneous rocks or associated with metallic ores, the statement is made that deeply buried carbonaceous sedimentaries were undoubtedly the source from which such carbon or bituminous matter was derived. This, I do not consider a reasonable or common sense view of the matter. Carbon is one of the elements of which the earth is composed. In the table giving the periodicity of the elements it comes sixth in the order of increasing atomic weights. It is an element formed like all the rest were formed, and must be as common to the interior of the earth as the rest of the eighty-odd elements so far discovered. The spectroscopic analysis of light from the sun, and the stars, shows the presence of carbon in the sun and in the colder stars. Thus with carbon, an element, found throughout the universe as well as on the earth, it is entirely reasonable to consider it as present in the interior of the earth with the other elements. Such being the case, the magmatic origin for the various forms of carbon in rocks and ores is a rational and logical conclusion. If but a small fraction of thought and effort was made along these lines, which is made in fostering the idea of the organic origin of the carbon found in the earth's crust, untold advances in this phase of geological science would result.

Jan 1, 1925

By Miguel Galindo, Eleuterio Rivera

Las características mineralógicas cada vez más compleja e inciertas de las distintas fases de minado, representan en general nuevos desafíos operacionales en las distintas etapas de los procesos minero-metalúrgicos: chancado, molienda, flotación, bombeo por mineroducto, filtrado y almacenamiento. Los cuales se enfocan principalmente en cumplir y optimizar la calidad final de los concentrados producidos sin incrementar significativamente los costos operativos y maximizando el uso de los recursos existentes.

Sep 29, 2023