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By H. E. Heide

"Before the war, the United States was the world’s leading consumer of tin, the industrial applications of which had become widespread. Domestic production was negligible, and requirements were met almost entirely by imports, principally from British Malaya, United Kingdom and China. Average annual imports for the years 1925-1929 amounted to 78,009 long tons.With the advent of war in Europe and signing of the Japanese-German pact, it was realized that foreign sources of supplies were threatened, and steps were taken by Congress to forestall critical shortages of tin and other minerals. These steps in regard to tin included stock-piling, improving reclamation and conservation, increasing South American production, constructing a smelter in the United States for treatment of tin, ores, and intensifying the search for domestic tin deposits. Annual imports were raised to 140,873 long tons by 1941. On 1945, annual imports had shrunk to 37,675 long tons and consumption had been reduced to 52,100 tons of primary and secondary tin but not tin content of scrap alloy.The Strategic Minerals Act, passed by the Congress in 1939, authorized the investigation of domestic tin deposits.As Alaska had supplied virtually all of the domestic output of tin, an investigation of Alaska deposits was undertaken in 1940 and 1941 by J. B. Mertie, Jr., and Robert R. Coats of the Geological Survey.The Lost River lode tin mine on the Seward Peninsula was examined by H. E. Heide of the Bureau of Mines in 1942. Possibilities for developing a significant amount of tin appeared favorable, and exploration of the ore bodies was started in August 1942."

Jul 1, 1946

By A. D. Stewart

El presente texto señala la geología como materia de enseñanza en las universidades británicas. En este sentido, si la geología se comprendía como una materia integral que trata del estudio de la tierra, aquí se ofrece una serie de cursos independientes. y especializados. Dicha variación es consecuencia del aumento de publicación de nuevos conocimientos. Como una alternativa a la organización existente en geología, se propone un sistema jerárquico de tres niveles, donde la escala juega un papel clave y la enseñanza, es un proceso orientador antes que descriptivo. La principal ventaja de este esquema sobre el tradicional es que la relación entre segmentos de materia en cualquier nivel es conducido por profesores en el siguiente nivel superior, sin que haya necesidad de colaboración detallada entre profesores dentro o entre niveles.

Jul 1, 1969

By José Canales Ruíz

La mina San Genaro, es un yacimiento de plata ubicado en el distrito de Castrovirreyna, Huancavelica, donde sus intrusivos están distribuídos según el rumbo de las vetas E-W, para unirse en profundidad y formar cuerpos de mayor dimensión. Así, el flujo mineralizante que proviene de las soluciones residuales de los intrusivos dioríticos, logra un ascenso casi vertical. En ese sentido, el presente texto señala la elaboración de las secciones longitudinales de plata en las vetas Poder, Trabajo, Milagritos, La Fe, Genarito, Alivio, cuya combinación práctica de los cocientes metálicos, resulta eficaz en la exploración, desarrollo, preparación y explotación de la mina

Nov 8, 1984

While SME is hosting its Annual Meeting at the Phoenix Convention Center, Feb. 28 to March 3, one of the finest collections of mining history will be on display just 15 blocks away at the Arizona Mining and Mineral Museum. Inside the museum, visitors will be treated to a treasure trove of minerals, gems, me¬teorites, rocks, fossils, mining artifacts, historical exhibits and interactive displays on modern mining. The museum is located at 1502 West Washington. For SME Annual Meeting attendees, this is a free, eight-minute Dash bus ride 15 blocks west of the Phoenix Convention Center.

Jan 1, 2010

The accompanying supply/demand flow diagrams and 10-year tables for mineral and fuel commodities present essential data required by government, industry, and others to formulate policies and programs that can help assure an adequate and continuing supply of mineral raw materials. The 10-year data base terminates with 1975 figures because adequate world information was not available beyond that date. The selected mineral supply/demand tables and flow diagrams comprise but one "output" from the massive body of information and data collected and compiled by the Bureau of Mines on a continuing basis covering mineral production, consumption, prices, shipments, imports, exports, and stocks, as well as industry activities in all States and abroad.

Jan 1, 2012

By K. Kohli

A case study involving a historic structure undermined by longwall mining is presented in this paper. The location of this study is in South Western-Pennsylvania; USA. The structure is 150-years old and subsided 4.5 feet. This paper discusses the mitigation measures taken to reduce the subsidence damage and its effectiveness.

Jan 1, 2002

By J. Arce

Recientemente algunos mineros han empleado métodos instrumentales de operación del subsuelo. Sin embargo, dado el paso del tiempo, las técnicas varían en efectividad, por lo que se hace necesario estar a la vanguardia de los nuevos instrumentos de exploración. En ese sentido, el presente trabajo analiza algunos estudios geofísicos en el pasado, así como sus posibilidades de uso en el Perú. Asimismo se anota lque os métodos de polarización inducida para exploración terrestre prfurida; los de activación neutrónica y fluorescencia de rayos para análisis químico en campo y los de análisis de gas de mercurio para campo y laboratorio, son los métodos que deberán utilizarse en el futuro cercano, así como algunas técnicas de sensores remotos serán especialmente útiles para evaluaciones regionales o continentales.

Nov 20, 1972

By Steve Kral

The mining industry has had three difficult years. Commodity prices have remained low and investor confidence in the industry has been shaken. And even though the Asian economy appears to be improving, it will be some time before this improvement will translate into better commodity price conditions for mining. In addition, increased environmental and social restrictions that have been placed on the industry in developed and developing countries have made mining a more difficult proposition. And, if that is not enough, the global mining industry has found itself in fierce competition with Internet businesses for investor capital. Despite that gloomy picture, more than 10,500 mining industry professionals from about 70 countries gathered in Toronto, Ontario March 5-10, 2000 for the Mining Millennium 2000 conference. This meeting was a joint effort between the Canadian Institute of Mining, Metallurgy and Petroleum(CIM) and the Prospectors and Developers Association of Canada (PDAC).The joint meeting also featured two trade exhibitions and more than 150speakers. PDAC’s trade show attracted about 400 exhibitors and an additional 200 in the concurrent Investors’ Exchange. CIM’s exhibition attracted about 600 equipment and service companies.

Jan 1, 2000

By Cabrera M. Manuel C

A fines de 1980, la empresa Minero Perú construyó una operación piloto de monitores y planta de lavado con una capacidad de 1,500 m3/día, incrementando la producción de oro a un 80%. En este sentido, el presente texto señala la producción de oro de esta minera peruana, utilizando dichas herramientas mencionadas. Para ello, se describe la geología, minado, características del monitor seleccionado, características de la bomba de alta presión, metalurgia y las plantas de lavado.

Oct 14, 1980

By Mark E. Schlesinger

Engineering design follows a six–step sequence. Demonstration of this sequence in materials engineering is less common. A case study is presented, using the 1989 paper by Gafner on the development of 990 gold-titanium alloy. This paper identifies a need, develops the problem, identifies alternatives, demonstrates the use of metallurgical principles to identify alternative responses, and shows how more favorable options are selected. The paper can also be used to illustrate engineering design as an iterative process. The paper is also useful as a starting point for more in-depth examination of specific elements of the design process, and lends itself to the creation of student exercises.

Jan 1, 2014

By R. F. Favreau, Patrice Favreau

"A blast with explosives creates vibration waves in the zone around the blast.The prediction of the intensity of vibrations is important because people in the cinity demand that the vibrations do not disturb them, and society imposes limits on the vibrations. The U. S. Bureau of Mines (USBM) showed that the easurement of the particle velocity U predicts the risk of damage from vibrations. A currentapproach of blasters to monitor vibrations is to measure them with a seismograph at several distances S, and create a graph of U vs. S and the explosive charge “W” according to the equation U = K / (S / W)N where K and N are constants that depend on the blast method and the nature of the ground over the distance S. Though useful, this equation is empirical, and the results predicted from it are very variable, as shown by figure 1 which indicates that a prediction of U can deviate significantly from the actual value. Moreover, a minimum of two seismograph measurements at two values of S are required to establish the curve. However, here now exists another very convenient method to predict U; it is with the simulator Vibmas, which is based on the fundamental principles of how a blast reates vibrations. This simulator takes into account not only W but rather all the blast parameters, the type of explosive and the properties of the rock. Moreover, to establish the calculation of U as a function of S, only one seismograph measurement is required rather than two as for the USBM method. This last difference is important because it makes it easy to predict U not only as a function of S, but also as a function of the orientation of S. On the site this allows much safer control of the vibrations, and the use of larger explosive charges which reduce excavation costs. The article presents results from a field case at a hydroelectric project in Canada, where the deviation was very moderate. Use of this vibration simulator on the Web is very easy."

Jan 1, 2015

By Mutombo Nombe, Avimanyu Das, Rick Honaker

Enhanced gravity separators (EGS) provide a more efficient separation than froth flotation when cleaning coal in the 150 x 25 µm particle size range. To improve the performance of an EGS unit, air bubbles were injected into the feed stream in an attempt to decrease the apparent density of the coal particles due to the formation of bubble-coal particle agglomerates. Air injection had a significant impact on operating characteristics and separation performance. Coal recovery was increased by 10 to 20 absolute percentage points while a 2 percentage point drop in the minimum product ash content was also achieved.

Jan 1, 2005

The basic objectives of mine roadways are to provide sufficient cross sections in order to meet the needs of accommodation of equipment, transport, personnel travel and ventilation. However, many roadways become damaged to the extent of needing maintenance, generally dinting, and in some cases requiring re-ripping. The damaging of a roadway is a result of several factors including geological properties of surrounding strata, method of roadway formation, type and spacing of support and so on. Among these factors, strata conditions play an important effect on the stability of roadway. Weak rocks cause excessive roadway closures and water softens some rocks and promotes the closure problem. In this paper, a scientific discussion on the effect of water on the stability of roadways is given on the basis of results obtained by means of in-situ investigation and laboratory rock tests.

Jan 1, 1996

By O. Bazhko, F. D. L. Uahengo, Y. R. S. Hara

Although the conventional acid-reductive leaching method effectively extracts copper (Cu) and cobalt (Co) from Cu–Co oxide ores, efforts to enhance hydrometallurgical performance are ongoing. This study evaluates the influence of sulphuric acid (H2SO4) and sodium metabisulphite (Na2S2O5) on metal extraction from Zebesha Cu–Co oxide ore using ferrous sulphate heptahydrate (FeSO4·7H2O) and ferric sulphate (Fe2(SO4)3) as lixiviants. Ore samples (<150 μm) were leached at ambient temperature for two hours, and metal concentrations were determined via X-ray fluorescence analysis. In the FeSO4·7H2O system, Co, Mn, and Ni recoveries increased w=ith Na2S2O5 concentration, reaching a maximum of approximately 80% Co at 150 kg/t, while Cu recovery remained below 5%. Conversely, with Fe2(SO4)3, Cu recovery peaked at 88% at 50 kg/t Na2S2O5, then declined to 79% at 150 kg/t. The addition of H2SO4 improved metal recoveries in both systems. Notably, 60 kg/t H2SO4 yielded 92% Cu extraction in Fe2(SO4)3, while Co, Ni, and Mn remained below 40%. However, in FeSO4·7H2O, Co recovery improved from 40% to 84%. These findings suggest Na2S2O5 is more effective for cobalt extraction with FeSO4·7H2O, whereas H2SO4 enhances copper extraction in Fe2(SO4)3.

Oct 24, 2025

By W. J. Atkinson

The first recorded discovery of diamonds in Australia was in 1851 in New South Wales. Subsequent prospecting has shown alluvial occurrences of diamond to be widespread through much of the Tasman fold belts of Eastern Australia. Production is estimated to be some 500,000 carats from several small alluvial fields. Despite extensive exploration, though, no primary rock source carrying significant diamond content has ever been confirmed in Eastern Australia. Conversely, diamond exploration of the older Western and Central Cratons of Australia during the past 30 years has discovered 12 fields containing 360 kimberlites, lamproites and lamprophyric volcanic pipes, dykes and other intrusives. Of those, 180 have been confirmed to be diamondiferous. Only one pipe, however, the 1200 Ma high-grade Argyle lamproite and associated nearby alluvials, has proved to be economically exploitable. Its current annual production is 40 million carats valued at about US$400 million. Production from the open pit will be sustainable until at least 2003.

Jan 1, 1995

By R. A. McIvor, R. Levac

"The Stobie No. 7 shaft, 14 ft diameter, double- drum skip hoist, was installed at the INCO Limited Frood Stobie Complex in 1942. Figure 1 shows the hoist layout. The hoist was originally equipped with babbitted journal bearings on the main drum shaft and pinion gears. In 1990, the hoist was modernized with a new braking system, two new 2000 hp D.C. drive motors, a thyristor armature supply and a PLC control system. The new drive motors were connected to the drive pinion gears with a gear type flexible coupling. The pinion gear journal bearings were refitted during the refit in 1990 as the existing babbitted bearings showed signs of wear. The pinion gear journal bearings had always run warm and had external cooling applied during the warm summer months. Figure 2 shows the journal bearings on the pinion shaft. The skip hoist main bull gear and two pinion gears were replaced in 1997 because of cracked bull gear spokes. New drive couplings were installed on the pinion gears and the pinion journal bearings were modified to allow some self-aligning properties to try to reduce the heating and wear on the babbitt. The modifications did not significantly reduce the heating problems and a decision was made in the spring of 1998 to convert the bearings to self-aligning, anti-friction-type bearings.The traditional roller bearings used on double helical pinion drive gears in hoist applications has always been double-row spherical roller bearings due to their high load-carrying capacity and misalignment allowances.Unlike single helical gears, double helical arrangements do not exert axial thrust on the pinion gear bearings, therefore, both bearings in the pillow blocks must float easily with any pinion displacement. Drum misalignment, thrust bearing end play and a multitude of other influences causes continuous axial displacement of the pinions when in operation. This constant displacement or “hunting” of the pinion gear to maintain its centre on bull gear often exceeds the axial clearance limits of spherical roller bearings thus resulting in a continuous sliding motion of the bearing outer rings against the housing seats. With time, the housing fit eventually wears, creating an out-of-round condition for bearing housing (maximum allowable cylindricity tolerance is IT4/2). When this happens, the pillow block housings must be replaced or re-machined to specification. Premature bearing wear and overheating will occur if a housing out-of-round condition is encountered."

Jan 1, 2001

By Claudia Monreal L., Dafne Herreros

"The Geological Modeling is the undisputed point of split of any type of mining method, the effect that the vision and experience of the geologists is propagated trough the development of the project and is an important part of the final success. The collection of information is taken in stages. In earlier stages uses the greater part of the budget and the strategy to store and manage this data collection, as its performing will define the destiny of the deposit and of the business. With this background the geology and its modeling receive great attention from the industry and care providers being a fertile field in research and innovation. "

Sep 1, 2017

By K. R. Fox

El objetivo del presente trabajo es replantear las ideas sobre la repercusión uso del carbón en la industria minera de los metales y no solo dentro de la industria carbonífera del Perú, en tanto representa materia prima en el proceso de preparación de los metales. Para ello, se busca obtener los tipos de carbón adecuados (antracita al carbón, bituminoso y sub-bituminoso, etc.)a la naturaleza de estas operaciones. De tal forma que su función no se reduzca al uso de la industria metalúrgica doméstica, sino adquiera una mayor importancia en la industria minera de los metales, así como la de los mineros en esta área.

Jul 20, 1955

The construction, commissioning and operation of a continuous pilot-scale selective agglomeration (oil agglomeration) unit are described. This plant has been used to recover fine coal from an effluent stream that is produced by a jig plant which scalps the coal from a New South Wales (Australia) colliery. The reject slurry is extremely fine (66.5% minus 53 um) and has an ash content of approximately 40%. The pilot plant can treat up to 0.3 tonne/h of this slurry, producing average product ashes as low as 9.1% and tailings ashes greater than 80%. The average yield observed was62%, which corresponded to a recovery of coal material of 88%. The operation of this pilot plant yielded data that enabled an economic assessment of this type of processing to be carried out. This study showed that selective agglomeration is an economically viable process for eliminating the substantial losses of coal to tailings ponds and minimizing consequent disposal and environmental problems. A commercial plant has been constructed and commissioned on the basis of the data obtained from this pilot-scale operation.

Jan 1, 1979

By Freddy Salazar, Segundo Velasquez, Robert Montes

Compañía Minera Coimolache, ubicada en la región Cajamarca, es una empresa a tajo abierto que produce oro y plata. El mineral es lixiviado con solución de cianuro de sodio, proceso del que se obtiene una solución pregnant que posteriormente se trata en la planta de Merrill Crowe y ADR según su ley. Sin embargo, debido a las precipitaciones, el agua de lluvia incrementa el inventario de solución con cianuro en el proceso, por lo que se hace necesario su tratamiento en la planta de detoxificación de cianuro. Ante este panorama, se buscó la oportunidad de reemplazo del cloruro férrico, identificando el agua ácida proveniente del depósito de material estéril como principal candidato para este reemplazo

Sep 29, 2023