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By Luis Briceño Arata

El presente texto describe los proyectos mineros desarrollados hasta el año 2000, el cual contempla los siguientes minerales: plata, hierro, fosfato, oro, carbón antracítico y bituminoso, así como las necesidades energéticas, hídricas y posibles fuentes del suministro.

Jan 1, 1975

By G. Wheeler

Epithermal gold exploration in the last decade has developed useful models for exploring new ore districts in Oregon. In Eastern Oregon, disseminated gold occurs in epithermal deposits that have been pervasively silicified and brecciated. Many gold prospects staked since 1980 are in fluvial and lacustrine sandstone and conglomerate deposits. Clay alteration products and disseminated pyrite may be present. Vein filling calcite and thin to thick quartz veins are common. Late stage quartz forms pseudomorphs after calcite in many deposits. Arsenic, mercury and gold are geochemically anomolous but silver is usually not. The epithermal deposits are located in part of the Deer Butte Formation or equivalent units. Exploration criteria include the presence of Deer Butte Formation or correlative units and NW structures cut by N-S basin and range structures.

Jan 1, 1987

By Daryl R. Tweeton

The Bureau of Mines measured the geochemical changes as H2S04 was used for in situ uranium leaching by Rocky Mountain Energy Company near Casper, Wyoming. Cores and ground water were analyzed before leaching. Water samples were taken from observation wells located between injection and production wells as the leach solution was brought up to full strength in several steps. Measurements were made of pH, Eh, temperature, conductivity, total dissolved solids, dissolved oxygen, HC03, U, V, Na, K, Ca, Mg, SO4, C1, Mo, Mn, Fe, Al, Si, F, P, As, and Se. The data were gathered to assist in geochemical modeling of leaching and to study the potential environmental effects of acid leaching. Environmental considerations appear favorable. For example, the concentration of Se, a toxic element often found in uranium deposits, stayed below the EPA standard for drinking water.

Jan 1, 1979

By S. Castro, L. Gutierrez

"Mining operations are often located in remote arid environments with limited access to fresh water. Shortage of fresh water in such cases makes it necessary to use seawater in mineral processing plants. Such plants treating Cu- Mo sulfide ores in seawater have been fully operational in Chile (e.g. Las Luces, Centinela). In many cases process waters used in commercial flotation plants (e.g. Mt Keith in Western Australia) are even more concentrated electrolyte solutions than seawater. This paper is an attempt at classification of the flotation operations carried out in process waters that are concentrated electrolyte solutions.INTRODUCTIONAccording to Gleick (1966), of the total Earth’ water resources 97.5% is in the oceans and ice caps, and thus only about 2.5% is fresh water. Shortage of fresh water in many parts of the world makes it necessary to use seawater in mineral processing operations. The existing commercial operations using seawater as well as recent research projects that deal not only with sulfide ores but also with apatite ores provide a lot of information that can now be generalized. The progress that has been made in this area is reviewed and based on this information an attempt is being made at classifying the flotation operations carried out in highly concentrated electrolyte process waters.SALT FLOTATIONFlotation in highly concentrated electrolyte solutions was studied by Klassen (Klassen, 1963). He reported that hydrophobic, bituminous coals, could float in salt solutions without addition of any other flotation agents. The process is referred to as salt flotation. Other inherently hyhrophobic minerals (e.g. talc, graphite, sulfur, etc.) were shown to behave similarly (Klassen and Mokrousov, 1963)As Figure 1 shows, some coals float quite well in solutions of Na2SO4, NaCl and NaNO3 (Klassen, 1963). While there are differences between the tested salts (explained by different foamabilities of these solutions) all the tests indicate that only bituminous coals float well in concentrated electrolyte solutions. 0.3 M solutions are quite sufficient to initiate a good and very fast flotation. If wettability of various coals is compared it becomes obvious that these well floating coals are very hydrophobic bituminous coals (Figure 2)."

Jan 1, 2018

By Paris V. Brough

This paper, which describes the practice of milling custom ore, in addition to that produced under company and lease operations in the Tom Reed mines, is one of a series 'being prepared by the Bureau of Mines. ACKNOWLEDGMENT Acknowledgment is made to W. B. Phelps, managing director, and Jack Zwinge, superintendent, far permission to publish, a-ad to G. E. Jarpe, the present mill superintendent, for his assistance in preparing the paper. LOCATION The mill is in Oatman, adjacent to the Benjamin Harrison shaft of the Tom Reed Gold Mines Co., in the foothills on the western slope of the Black Mountains, western Mohave County. The railroad shipping point is Kingman, Ariz., 25 miles northeast of Oatman. Paved highway U. S. 66 passes by the mill. The altitude is approximately 2,700 feet.

Jan 1, 1937

By N. Menad

Thermal treatments of five different types of non-ferrous metallurgical wastes, under controlled atmosphere, were carried out at temperatures lower than 800 °C. The aim of these treatments was to reduce the toxic elements content and to increase that of valuable metals in the residue. <Best results were obtained by their treatments in air or hydrogen or successively both of them. Simple treatments using air or hydrogen of three samples allowed the elimination of more than? 95 % of their toxic elements and&apos; almost doubled their valuable metals&apos; concentration. For the rest two samples, combined treatment was necessary for their efficient decontamination and the concentration of valuable metals, in the treatments residue, to a reasonable value. Most of the solids issued from these treatments can be recycled in .the current non-ferrous metallurgical processes.

Jan 1, 1995

By J. W. Watkins

This report describes in detail methods of making corrosion tests and chemical analyses that have been used extensively and satisfactorily in a study of plants in which various surface, waters and brines are conditioned and used for water flooding, brine disposal, and reservoir-pressure maintenance in Kansas, Oklahoma, and North Texas. The tests and analyses described were designed and adapted for use in the field in determining the relative corrosive and plugging tendencies of waters from various sources conditioned by different methods. Although the described methods were developed and used in testing oil-field waters in the Midcontinent oil-producing area of the United States, these same methods should be equally applicable to testing oil-field or highly mineralized waters throughout the world. Many of the methods used have been discussed by the writer (1)2/ previously, and some of them have been used for similar work in other laboratories. Early in the development of the practice of the subsurface injection of brines for disposal and increasing the recovery of oil, it became evident that different methods of chemical treatment and conditioning equipment would have to be devised to sustain desired injection rates into water-input wells. These changes became necessary because the highly mineralized waters produced with petroleum from deep formations became chemically unstable when pumped to the surface, owing to loss of dissolved gases as pressure and temperature dropped to atmospheric and to the contact with atmospheric oxygen at the surface.

Jan 1, 1954

By M. L. Whisman

Three samples of waste lubricating oil were re-refined by processes developed by the Bureau of Mines and reformulated with additives to meet designated requirements for viscosity and service. Quality-defining bench-scale tests were used to compare and evaluate the quality of these three motor oils, eight commercially re-refined lubricating oils, and three new lubricating oils. Most of the re-refined oils studied could not be distinguished from new oils by the bench tests used to define quality. There was some evidence, however, that one and perhaps more of the re-refined products investigated might not meet all of the quality standards of new lubricating oil, suggesting the need for better quality controls by re-refiners.

Jan 1, 1974

By Valenta R. K

A technique is presented for the integrated forward modelling of the three-dimensional structure and the geophysical response of multiply deformed terrains. This technique allows information collected by field geologists and geophysicist to be reconciled by the development of a simplified kinematic structural history of the area. The structural modelling simulates the deformation history of the area in terms of a succession of structural events, such as folds, shear zones and intrusions. The interaction of these events with a starting stratigraphy results in the prediction of the geometry of the structures. By specifying geophysical rock properties for the units in the initial stratigraphy predictions are possible for the potential field anomalies for gravity and magnetics. This approach is suited to a range of applications, and its uses in the modelling of regional structures, testing of geophysical data processing, volume balancing, multiply constrained inversion and training are discussed.

Jan 1, 1995

By W. E. Robinson

Samples of raw oil shale and kerogen concentrates were oxidized by alkaline potassium permanganate, air, nitric acid, oxygen, and ozone to obtain information about the chemical structure of organic kerogen in oil shale. In one test, oil shale and oil-shale products were oxidized exhaustively with alkaline potassium permanganate, and the distribution of the organic carbon in the final oxidation products was determined. Comparing results of this oxidation with those obtained from other carbonaceous materials and known compounds gave information about the structure of kerogen. Alkaline potassium permanganate oxidation also was used partly to degrade kerogen into soluble products for characterization purposes. Structures present in these degradation products were indicative of type structures originally present in the kerogen. Nitric acid, oxygen, and ozone were used also for partly degrading kerogen to soluble oxidation products. Carbon-balance oxidation tests using alkaline potassium permanganate showed that Colorado oil-shale kerogen differs from many other carbonaceous materials such as coal and kerogens from other areas. Composition of the degradation products indicated that Colorado oil-shale kerogen is predominantly cycloparaffinic and saturated heterocyclic structures with some long-chain paraffinic and aromatic structures present. The ring systems may be connected through short carbon chains or bridges containing oxygen, nitrogen, and sulfur.

Jan 1, 1963

By G. W. Jones

The determination of the ignition temperature of diethyl ether and ethylene in air and omen which is described in this report was made primarily for comparison with similar determinations of other compounds in the same apparatus and using the see laboratory technique. The investigation was conducted at the Pittsburgh Experiment Station of the United States Bureau of Mines with the cooperation of Merck & Co., Inc.

Jan 1, 1935

By Hinde J. S

The Fitzpatrick Orebody is a three and a half million tonne fault bounded portion of the early-middle Proterozoic Broken Hill Orebody.The Fitzpatrick Orebody was discovered in 1975 by diamond drilling from the 36 Level Exploratory Drive. This followed persistent geologically oriented exploration and a courageous decision by mine management to deepen No. 3 Shaft to provide exploratory development across the Globe Vauxhall Shear and allow effective drilling of the target area.The stratiforrn oebody consists of three lenses, the lead rich No. 2 and 3 Lenses and smaller zinc lode. They represent a down plunge extension and boudinaged, fault-bounded portion of the main Broken Hill ore lenses. The surrounding host rocks are extensively faulted and jointed due to complex history of movement on the bounding shears. This results in extremely poor ground conditions during mining. The ore was delineated for mining development using three dimensional fan drilling from exploratory and hanging wall drive drill sites.

Jan 1, 1990

By Gilbert Soler

PRODUCERS of alloy steels recognize the importance of chemical composition in rela-tion to the hot-working properties and the typical surface defects found in their prod-uct. Each analysis of steel has its own peculiar characteristics. Under conditions of standard mill practice each analysis is susceptible to certain types of defects. Mill practice must be varied to obtain the best combination of surface and internal quality in the product. Chemical composition influences the cast structure and crystallization character-istics of the ingot. It also determines the rate of heating and cooling, the plastic hot-working range, and the phase structure of the steel at various temperatures as well as the tendency toward scale formation and decarburization, This paper endeavors to emphasize the manner in which chemical composition affects the various properties of steel, and to indicate the relative impor-tance of these factors in relation to the hot-working properties and surface charac-teristics of killed steel. The influence of chemical composition may be outlined as follows: I. Effect on the cast structure of steel, including: A. State of deoxidation, and type of inclusions. B. Gas content of steel. C. Freezing point and melting point of steel.

Jan 1, 1940

By W. K. Katoto

The Tailings Leach Plant (TLP) of the Zambia Consolidated Copper Mines Ltd at Nchanga was commissioned in 1974 as the world&apos;s first largest successfully operated agitation leach SX-EW plant for copper production. The design, development and operation of the plant soon after commissioning termed as TLP stage II has been described by Holmes et al (1). In the initial phase the plant was designed to treat approximately 25,000 tonnes per day of current flotation tailings from the Nchanga Concentrator operations, and had a design capacity to produce 75,000 tonnes per annum of copper. Further expansion took place in 1986, and TLP stage III was successfully commissioned to treat an additional 20,000 -25,000 tonnes per day of large reserves (over 135m tonnes) of reclaimed tailings stockpiled since the early 1930&apos;s in four paddock type tailings dams (T01 to T04). The salient feature of TLP stage III expansion described by S K Mwenechanya et al (2 -3) was the installation of the world&apos;s largest Horizontal Belt Filter Plant with 26 filters each of 80 m2 filtration area.

Jan 1, 1996

By A. M. Evans, J. H. Soulé

"INTRODUCTION Deposits of iron ore in Cherokee County, Tex., have been worked at various times in the pact, and the ore has been smelted in small local blast furnaces.Recently it was proposed to establish a charcoal blast furnace with a wood distillation plant to produce charcoal for fuel and byproducts. Financial assistance from the Reconstruction Finance Corporation was sought by George Easley and associates to enable them to purchase, move, and erect the furnace and build the required accessory plants. The furnace was to be moved from Pembroke, Fla.In August 1941, the Bureau of Mines was asked by the Office of Production Management to check the development work of Easley and associates and to ascertain (1) the iron-ore reserves, (2) the cost of mining ore and delivering it to the blast furnace, and (3) the grade and character of the ore. The Bureau of Mines was advised, while the investigation was in progress, that approximately 1,000,000 long tons of measured reserves would be sufficient to demonstrate the feasibility of operating the properties.Although deposits of iron ore are widely distributed in Cherokee County, only the Pryor Mountain, Banks and Cherokee, J. P. Acker, and Citizens State Bank tracts were sampled thoroughly by the Bureau of Mines. The iron-ore rights on these are owned by the New Birmingham Development Co., the Cherokee Development Co., or by individuals. Options to lease the ore rights were obtained by Easley, who obtained options on the Hawes Peach Orchard and Bradford tracts, also, which were examined only cursorily by the Bureau."

Aug 1, 1947

By R. V. Higgins

A numerical method is presented to calculate the isopressure (isobar) lines and streamlines for an oilfield from the pressure distribution. A knowledge of these lines is useful in the study of the flow of fluids in underground reservoirs, especially for those containing gaseous and/or liquid hydrocarbons. This work was done primarily to enable determination of the shape factors needed in the calculation of petroleum reservoir performance. However, it has application for the flow of water in aquifers, or electricity or heat in odd-shaped geometry. Techniques previously developed were used to calculate the pressure distribution. From this pressure distribution, the isopressure lines were calculated accurately by the method presented in this paper. Then by successively projecting orthogonal lines from one isopressure line to another, the streamlines are determined. From the coordinates of the isopressures and the streamlines, the shape factors can then be determined by a published method. Computer methods are presented to calculate the streamlines and isopressures for any well-spacing pattern existing within a field with multiple wells. The method reproduces the flow net for several well configurations having extensive geometrical variations. Such information provides the petroleum engineer with data from which he can compute oil recoveries for different patterns and thereby maximize the recovery of hydrocarbons from the reservoir.

Jan 1, 1972

By M. A. Elliott, H. H. Schrenk, L. G. Berger, John C. Holtz

"INTRODUCTION Interest in the possibility of using Diesel 6/ engines for haulage power in mining and tunneling is increasing in the United States, owing largely to the reported successful use of Diesel locomotives in European coal mines and to the comparatively recent development of automotive Diesel engines in this country. The extent of this interest has been evidenced to the Bureau of Mines by numerous requests for information as to the factors that must be considered if Diesel engines are to be used safely underground.Proponents of the application of the Diesel engine to underground haulage base their claims for its safety upon a comparison with the gasoline engine, assuming that (1) the carbon monoxide content of Diesel exhaust gas is always low and that (2) fire and explosion hazards from Diesel fuel are minimized because of its low volatility. In these respects the Diesel engine appears less hazardous than the gasoline engine, whose use underground has been discouraged by the Bureau of Mines and other organizations interested in safety in mining. However, such generalizations cannot be accepted as conclusive evidence that safety is inherent in Diesel engines in underground service, as European experience indicates that certain hazards may accompany their use. Such hazards were discussed in a previous publication 7/ that reviews developments in the use of Diesel locomotives in European coal mines.The Bureau of Mines has initiated a study of the hazards that may attend the use of Diesel engines underground to obtain first-hand information that may serve as a basis for recommending sale practices under conditions existing in the United States."

May 1, 1940

By D. L. McCain

In considering slurry transportation for Consolidation Coal Company&apos;s Loveridge Mine in Northern West Virginia, many things were taken into account. The advantages of slurry transportation in comparison to shuttle car, belt and rail transport have been given in previous publications." These include increased safety and the potential for increased productivity. In addition to these considerations, the slurry transport system installed in an existing mine provides an alternate or additional transportation mode to the one already existing. In the Loveridge Mine, this is rail haulage. Since the rail system is a single track system and the distances involved are several kilometers, it is not always possible to provide for haulage of loaded cars, return of empties, supplies and maintenance in an efficient manner. Slurry transport of the coal from the production faces to the preparation plant allows the rail system to fulfill the remaining transportation needs in an efficient manner. Consol initiated development work in slurry transportation in the early fifties leading to the construction and operation of the 174-km (108-mile) Cadiz-to-Cleveland pipeline which carried 1,200,000 metric t/y (1,300,000 t/y) from 1957 to 1963. Development work on coarse coal slurry transportation for underground mines started in 1970 with feasibility tests on coarse coal at Conoco&apos;s Ponca City, Oklahoma, slurry test facility. A series of tests were conducted in several locations as development work proceeded on the various subsystems, mechanical equipment and controls required to produce a working system to follow a continuous miner in a room-and-pillar type mine, then to combine the coal production from several mine faces for mainline transportation to the preparation plant. The face system, including the crusher-pump vehicle, hose hauler vehicle, slurry booster pump units, return water unit and 900 to 1,200 m (3,000 to 4,000 feet) of pipeline was brought together for the first time and tested as a system at Consol&apos;s Robinson Run Mine in northern West Virginia in 1975. A pipeline wear test at the Loveridge Mine where 300,000 tonnes (330,000 tons) of minus 127-mm (5-inch) run-of-mine coal were pumped from the raw coal bin into the preparation plant and a large scale test in Ponca City on a multiple feed sump where several slurry flows could be combined to provide surge capacity and a constant reclaim rate for mainline transportation completed the preliminary testing for a complete system. A decision was made to commit the system to a mine, and the south half of the Loveridge Mine was chosen. This site required the transporting of coal from one longwall and two continuous miner development faces. To prevent startup and unexpected problems in the slurry system from shutting down production of coal from the longwall face, the rail car loading point from the main section belt was chosen as the feed point for the slurry system and the design would allow for rapidly switching from one transport mode to the other. Scheduling of required development entry work and the developmental nature of the system led to a decision to install only one continuous miner face slurry transport system rather than two for this first system. The type of continuous miner in use at the mine for the foreseeable future was the Joy 2BT6 twin boring machine. This machine cuts a stable, arch-shaped entry and was therefore allowed to mine about 26 m (85 feet) of entry before roof bolting was re¬quired. Since peak production from this type of machine was not high, a smaller transport system could be used with it.

Jan 1, 1981

By W. S. Sanner

This report describes the commercial application of the launder screen in anthracite-industry fine-coal cleaning operations. No new device, the launder screen has been used since the early part of the present century to size, screen, classify, and deslime the fine-anthracite sizes (Buckwheat Nos. 1 through 5) recovered by "river-coal" men dredging along streams draining the anthracite fields. The launder screen is stationary, has no moving parts, requires ample water for operation, and can be constructed economically on the job. Essentially, it consists of a wooden trough with baffles placed through its width to form a well system. The wells are covered by fine-mesh woven-wire screening. Each well is tapped with a number of orifices, and the hydraulic suction head developed in this manner removes high-gravity fines and slimes through the screening as underflow to waste. Material retained on the screen surface discharges as overflow product.

Jan 1, 1954

By JAMES QATLEY

THE atmosphere, which plays such an important part in the manufacture of iron and steel, is the most variable element involved in its several processes; and particularly is this true of the blast-furnace process, which consumes air in large quantities. At no time since the blast-furnace became an important and widely used apparatus-even when it was operated in the most crude manner-have the variations in composition of the raw materials used been as frequent and as great as the variations in humility of the atmosphere. Important, improvements have been made in the blast furnace and its accessories, such as the hot-blast stoves, the increase in size and change in the shape of the furnace, more efficient blowing engines, the increased protection given to the bosh walls, and the careful preparation of&apos; the raw material, all of which have exerted a pronounced influence on the furnace-operations from a metallurgical standpoint. But during the past eight years little advance has been made in this direction; the fuel-consumption has not diminished, nor has there been any material increase in production. Within that period, however, there has been witnessed the greatest development in appliances for the economical handling of material. So complete has been the work in this direction, that, except in isolated cases, in this country at least., a further extension does not hold out much promise of a satisfactory return on the investment required. It seemed that, with the exception of the gas-engine, we had about reached the limit, for like a strong wall, the atmosphere, with its humility as variable to-clay as when first blown into a primitive blast-furnace, appeared to stand as a Barrier to

Jan 1, 1905