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By Doris Hiam-Gálvez

El presente trabajo describe las últimas tecnologías que mejoran la minería en América Latina y la eficacia en el procesamiento del mineral. Así también se revisa el modo innovador de energía a través de la fundición de sales con energía solar, particularmente en regiones desérticas de América del Sur. Cada tecnología ofrece mejoras sustanciales en eficiencia, capital, y costos operativos y contribuye a la reducción el impactom ambiental de las operaciones mineras.

Feb 1, 2012

By Saulo Brinco Diniz

As ligas de alumínio da série 7XXX são largamente utilizadas no setor aeronáutico devido sua alta razão resistência mecânica / densidade. O que proporciona uma alta resistência mecânica para as ligas da série 7XXX é a adição de elementos de ligas e tratamentos térmicos adequados, como por exemplo o T7351. Este trabalho teve como objetivo, estudar a evolução microestrutural de uma liga de alumínio 7475-T7351 processada por laminação convencional a temperatura ambiente, e posteriormente submetida a tratamentos térmicos de recozimento para recristalização. De acordo com os resultados apresentados, a amostra que foi submetida ao tratamento térmico de recozimento para recristalização a temperatura de 500ºC durante 15 minutos recristalizou, enquanto que a amostra que foi tratada a 350ºC durante 1500 minutos teve coalescimento dos precipitados.

Oct 30, 2017

By Larman J. Heath

Preliminary results of an explosive fracturing-solvent injection heavy oil recovery experiment conducted by the Bureau of Mines at a shallow oil reservoir near Bartlett, Kans., are given. Three wells 35 to 50 feet apart were drilled to a depth of 360 feet, and an open hole interval from 300 to 350 feet in the Bartlesville Sandstone Formation was explosively fractured with 3,000 pounds of pelletized TNT in each well. Laboratory tests were made on cores obtained from these wells to confirm the suitability of using an aromatic-type solvent. Injection of a 74-percent aromatic solvent was begun into one well and continued intermittently for approximately 2 months. Crude oil production amounted to 29.6 bbl, or 11.7 percent of the total oil con¬tained within the three-well interwell zone.

Jan 1, 1972

By M. A. A. de Klaver

Functional Description Figure 1 is a typical flowsheet for a system for solid fuel addition to filter cake. Solid fuel, coal, coal breeze, or charcoal, is fed from a,stockpile to a surge hopper. The solid fuel is metered into a grinding mill. The fuel is dried and ground in a grinding mill. The on-size particles are removed from the mill by air sweeping. The ground solid fuel is separated from the air stream by a cyclone and stored in a surge hopper. The ground solid fuel is then pneumatically conveyed to a small hopper in the balling area. The fuel is proportioned into the filter cake just prior to mixing. An efficient mixer is very important to have a successful operation. The exact flowsheet would depend on a number of factors including what fuel is used, how the fuel is received, and the cnaracteristics of the fuel as received. Availability of floor space in the plant may also affect the flowsheet. For example, drying air may be supplied from the pellet furnace if the grinding mill can be located near the grate, or the pneumatic conveying system and a surge hopper may be eliminated by placing the grinding mill adjacent .to the mixing area. Also, for a multiple line plant, a ball mill rather than a roller mill may be more suitable.

Jan 1, 1980

By Geoffrey C. Huggins

Diagnostic: tests were performed on a production ST-5A Load-Haul-Dump machine manufactured by Wagner Mining Machinery Company to evaluate and rank order noise sources. The diagnostic evaluation indicated that the major noise sources were the transmission, the engine, and the cooling fan. This phase was followed by implementation of recommended noise control treatments, which included vibration isolation of the transmission, a transmission enclosure, an engine enclosure, and modifications of the inlet to the cooling fan. The final step in the program was an underground operational period which began on 31 August 1976 at the National Gypsum Mine in Shoals, Indiana. The noise control treatments successfully reduced the LHD operator noise exposure by 7 dB(A), thus increasing its allowable operation time by a factor of 2.7. Actual measurements made underground using noise dosimeters have indicated that, during, a typical shift, the noise control treatments have reduced the fractional exposure to an allowable level. The report discusses the mechanical aspects of the LHD, its noise sources, the treatments applied, the final levels achieved, and field experience with the noise-controlled machine.

Jan 1, 1977

THE Synthetic Liquid Fuels Act. (30 U.S.C., 321-325, and amendments) became law April 5, 1944, and a period of intensive research and development in this field was begun by the Bureau of Mines. As part of this program, bulletins were published on pressure hydrogenation.3 the Fischer-Tropsch synthesis,4 anal oil shale.5 The Bureau also has published a short bibliography on coal gasification,6 mostly of a theoretical nature. Because coal gasification is prerequisite to either the Fischer-Tropsch or coal-hydrogenation processes, publishing this sizable collection of technical information in this form will be valuable. The material will be presented in three parts, as follows: I. United States Patents. II. United Kingdom Patents. III. Other Foreign Patents. The domestic patents for this bulletin were collected between 1953 and 1955.

Jan 1, 1960

By Eddy Valencia, Miguel García, Edgar Contreras

Anglo American Quellaveco S.A. (AAQ) ha implementado un centro de control geotécnico con monitoreo en tiempo continuo 24h/7d incorporando tecnología basada en interferometría de apertura real y sintética, lo cual permite tener total cobertura de todos los taludes expuestos del tajo y poder identificar movimientos precursores y su evolución durante los trabajos de extracción. Con la incorporación de este sistema y las mejores prácticas de monitoreo, como discriminar errores en las lecturas, identificación de anomalías atmosféricas y escogiendo periodos de cálculos adecuados, se obtienen datos de calidad que representan el comportamiento tendencial, las magnitudes de deformación y velocidad, permitiendo obtener datos de calidad para la aplicación de pronósticos de falla acertados

Sep 29, 2023

By H. C. Meister

THE zinc-smelting industry of the United States has grown very rapidly in recent years and bids fair to outrival that of all other countries in the future. On account of the geographical situation of the chief ore-supplies, the industry may be divided into two main groups, the eastern and the western. The eastern and older group includes the works of Pennsylvania, New Jersey and Virginia, which practically control their own ore-supply. The western group includes the works of Illinois, Missouri, Kansas, Wisconsin and Indiana, which do not control their own ore-supply, but are compelled to buy the ore in the open market. It is for this reason that the western zinc-smelting industry has been undergoing continual changes since its inception 40 years ago. During the early discoveries of lead- and zinc-ore in the lead- and zinc-districts of Wisconsin and northern Illinois, the zinc-ore (sinithsonite or " bone " as the miner calls it) had no value and was considered waste; but later, when this ore was found in large quantities, it attracted the attention of metallurgists, which finally resulted, during the early sixties, in the building of the Matthiessen & Hegeler Zinc Works at LaSalle, Ill., the pioneer zinc-works of the West. A few years later, zinc-ore was discovered associated with the lead-ore in Jefferson county, southeastern Missouri, which started the industry at Carondelet or South St. Louis. Still later, the discoveries of zinc-ore in the lead-ore region, first' at Granby and then around Joplin, lead to the introduction of the industry in the southwest Missouri and Kansas districts. At first the development of the industry was slow, but it progressed steadily and it is now one of the leading metallurgical industries of the middle West.

Jan 1, 1905

During fiscal year 1966 the Bureau of Mines published 99 scientific and technical papers and engaged in 67 research projects on petroleum, natural gas, and oil shale. A basic appropriation of $3.4 million was supplemented by $1 million in cooperative funds from other Governmental agencies and industry groups. Petroleum conservation was advanced by development of scientific knowledge and improvement of technologic methods in both the extraction and utilization of petroleum, natural gas, and oil shale. Experimental work was carried out at research centers in Bartlesville, Okla., and Laramie, Wo., and in laboratories in Morgantown, W. Va., and San Francisco, Calif. ACHIEVEMENTS IN FISCAL YEAR 1966 Bureau of Mines--Petroleum Research in fiscal year 1966 (July 1, 1965- June 30, 1966) was involved in many public issues--air pollution, peaceful uses of nuclear explosives, utilization of oil-shale resources, computerization of recovery-stimulation techniques, and fuels for supersonic airplanes. Scientific contributions included compositional studies of petroleum and oil shale, determination of thermodynamic properties of petroleum compounds, development of analytical techniques, and correlations of petroleum properties with geologic occurrence. Technologic advances included rock-fracturing research, in situ combustion studies, waterflood techniques, use of radio-tracers to study stability of petroleum fuels, and hydrogenation as a tool to prepare shale-oil products.

Jan 1, 1968

By Marianella Guerrero, Gustavo Loyola

La anisotropía y geoestadística local es una técnica que optimiza los parámetros geoestadísticos involucrados en los modelos basados en variogramas de forma local, lo que garantiza una mejor adecuación entre el modelo geoestadístico y los datos observados. Esta técnica se utiliza para determinar y tener en cuenta los parámetros que varían localmente para abordar las anisotropías no estacionarias y locales, permitiendo centrarse en las particularidades locales de la distribución de las leyes. Esta técnica es útil para mejorar la precisión de los modelos geoestadísticos, ya que permite abordar las anisotropías no estacionarias y locales, lo que resulta en una mejor adecuación entre el modelo y los datos observados.

Sep 29, 2023

By L. C. IlsLey

The theory and practice followed by the Bureau of Mines in investigating electrical equipment4/ made for service in gassy mines are of particular interest not only to manufacturers but also to those organizations that deal with safety anal inspection at the mines. This publication purposes to discuss the theory upon which tests of equipment in explosive atmospheres are based and to consider inspection and other matters pertaining to investigations made by the Bureau in ascertaining whether a machine merits approval. The material in this report is taken from an earlier bulletin,5/ which is row out of print, and has been revised and brought up to date to make the information again available to manufacturers, inspectors, and others interested in the development of safe equipment.

Jan 1, 1954

By T. L. Johnston

A review of technical literature of the last quarter century discloses that much experimental work has been carried on in an effort to develop commercial processes for making sponge iron. In addition to the work that has been recorded, other work has been done the results of which have not been published. The degree of success or failure of these investigators does not detract from the fact that the problem has its challenging aspects and practical possibilities that encourage further investigation. The purpose of this report is to record information derived from recent experimental work that .had its 'objective the development and demonstration of one method of producing sponge iron. Work of other investigators was studied and applied wherever possible.

Jan 1, 1948

Lead Tariff.--The full House Ways and Means Committee approved H.R. 6089 which will have the effect of reducing the tariff on unwrought lead to 3% ad valorem, with a floor duty of 1.0625 cents per pound, compared with the currently effective rate of 3.5% ad valorem. Consideration is also being given to tariff rates on imports of red lead and litharge from Mexico. A consortium of domestic producers has appealed to the Office of the Special Trade Representative (STR) requesting a return to tariff schedules which were in effect prior to the concessions made effective on January 1. Mexican producers have filed a proposal in favor of lower duties, and the matter now awaits a ruling by the STR. Ferrous Scrap Exports.--After holding public hearings and receiving public comments in May, the Department of Commerce announced that it would not institute formal monitoring of ferrous scrap exports, as requested by the Ferrous Scrap Consumers Coalition. The Department said, however, that it would follow the trend of scrap exports and prices. Ferrous scrap prices are currently low and supplies are reported to be adequate.

Jan 1, 1980

This briefing was sponsored by the Bureau of Mines to summarize ongoing and recently completed chromium-chromite research and resource assessment activities by the Bureau. Through the series of 18 presentations compiled herein, Bureau personnel covered a wide range of topics including U.S. chromite and chromium trends and usage patterns; foreign and domestic resources; and research activities on mineral characterization and beneficiation, chemical and pryometallurgical processing of chromite and chromium-bearing wastes, new low-chromium alloy and coating substitutes, corrosion- and oxidation-resistant stainless steels, and chromium-containing refractories.

Jan 1, 1986

By AIME

NEW YORK'S largest hotel, the Pennsylvania, will be filled with mining and oil men and metallurgists the third week of February when some 3000 AIME members, their wives, and guests will gather for the Institute's 1948 Annual Meeting-its 166th general meeting. Except for the usual Sunday afternoon and evening sessions of the Mineral Industry Education Division at the Columbia University Men's Faculty Club, the big assembly will be under one top and members will not this year have to consult compass and map to find their next session. Possibly enervated by the stupendous effort of the Anniversary Celebration last spring and the plethora of highly successful fall meetings, the various committees have been a trifle slow in arranging their social and technical programs, but in mid December as we go to press there is already much to report indicative of substantial fare and high interest. The definite timetable schedule will appear in the February M&M.

Jan 1, 1948

By Gino Bianchi, John Connor, Lila Beckley, Linda Hall

Hemos evaluado y demostrado la aplicabilidad de una nueva y eficiente metodología para desarrollar niveles de protección ecológicos específicos para un sitio que son menos conservadores que los ECA para suelos, pero con un enfoque que ahorra tiempo y es más económico que los métodos tradicionales. Los resultados de nuestra investigación demuestran que los valores calculados son entre 20 y 60 veces superiores (menos conservadores) para cobre y entre 15 y 250 veces superiores para cadmio que los ECAs para suelo que podrían ser aplicados en evaluaciones ecotoxicológicas en el Perú.

Sep 1, 2017

By Fábio de Oliveira Braga

Blindagens cerâmicas são frequentemente utilizadas para proteção contra projéteis de alta energia, como os de calibre 7,62 mm e 5,56 mm. Recentemente, foi demonstrado que a modificação da geometria da face de impacto, de plana para convexa, possibilita uma melhor distribuição das tensões geradas pela interação do projétil com o alvo. Este efeito provocaria um aumento na absorção de energia do projétil, proporcionando uma maior segurança ao usuário. No presente trabalho caracterizou-se uma blindagem com a face cerâmica convexa, por meio da metodologia da norma NIJ-0101.06 (2008), ou seja, pelo ensaio balístico com medição do trauma em um material de referência que simula a consistência do corpo humano. Este ensaio visa a aplicação do material em coletes balísticos. Foi observada uma melhora significativa no desempenho balístico após a modificação da geometria.

Oct 30, 2017

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 Catherine C. Kilgore

The Bureau of Mines investigated the availability of fluorspar (CaF2) from 36 U.S. and 50 foreign mires and deposits in 13 countries. Only 6 U.S. properties are considered to be economic, as 29 domestic deposits were found to have an average total cost of production that was uneconomical at a breakeven (0-pct) discounted-cash-flow rate of return (DCFROR). The 50 foreign properties evaluated represent at least 55 pot of demonstrated fluorspar resources located in market economy countries and China. Al I evaluated foreign operations were found to be economic to marginally economic in January 1984 dollars when compared against published prices for each country. Reserves for 56 properties totaled 97 million metric tons (mt) (recoverable Ca F,) from demonstrated ore resources of 344 million mt that contained 123 million mt CaF2. The average total cost needed to cover all costs over the life of each operation was determined for all recoverable fluorspar products. Comparisons of ruining, beneficiation, and transportation costs per metric ton of fluorspar concentrate illustrate advantages between countries. Of the three countries with the greatest fluorspar production, China, with its high-grade, low-cost operations had the lowest weighted-average total cost of production ($38/mt concentrate), Mexico was next, at $54/mt concentrate, and benefited in U. S. dollar terms from the devaluation of the peso. The Republic of South Africa needed an average of $90/mt of concentrate to cover all costs of production at its large low-grade deposits.

Jan 1, 1985

By Catherine T. Ziten

Introduction ?Environmental assessments required for permitting ?Focus on ammonia produced through mine construction & blasting ?Water quality guidelines: federal, provincial, IGO ?Reported values are typically estimates from other projects ?Predictive modelling of ammonia aimed to assist planning

May 1, 2009