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By Mike Treffy

El presente texto describe las características geoquímicas de las rocas ígneas del tipo HHPG (High Heat Producing Granites) en los Andes peruanos. Dichas rocas tienen diferentes edades geológicas y están relacionadas a los depósitos minerales como estaño, plata, cobre, zinc, plomo, uranio, etc y están ubicadas al extremo sur de la Cordillera Oriental y norte del Batolito de la Cordillera Blanca. Asímismo, en base al procesamiento geoquímico de la de ANDESDATA, se demuestra que estos granitos y rocas volcánicas félsicas corresponden a diferentes series magmáticas y que este tipo de rocas pueden relacionarse a altas concentraciones de plata, oro, cobre, zinc, molibdeno, uranio, favoreciendo la circulación de fluidos hidrotermales a grandes distancias de las intrusiones y rocas volcánicas bastante diferenciadas.

Sep 21, 2013

An active list of permissible explosives was published in December 1936 as part of Bureau of Mines Report of Investigations 3324, under the title "Active List of Permissible Explosives and Blasting Devices Approved Prior to July 31, 1,936." This list included 170 brand names. Changes in the list that have been authorized to June 30, 1937 placed 35 additional brands of permissible explosives on the active permissible list as a result of tests, changes in brand names, or transfer from the inactive list. Ten permissible explosives were transferred from the active to the inactive list. The present list contains 196 brand names, one explosive having been placed on the list subsequent to June 30, 1937. The brand names of the permissible explosives placed on the active list are as follows: [ ]

Jan 1, 1937

By Higuchi K

In this paper, the history of Japanese coal and gas outbursts is presented and circumstances and countermeasures at the time cf outbursts are summarized statistically. Then the present meth- ods for prevention used practically in Japan are introduced. From statistics, it was reconfirmed that Japanese coal and gas outbursts have occur- ed frequently in the district of geological disturbance, symptoms immediately before out- burst occurrence were the phenomena in connec- tion with failure of a coal seam and outbursts have occurred many times when the number of boreholes had not been sufficient to degas. One of the principal protective method adopted in Japan is the large diameter gas drainage boring which also posesses a stress relief effects. There is a tendency to make diameter of borehole larger to increase both stress relief and degassing effects.

Jan 1, 1986

Jan 1, 1966

By H. M. Allen

La presente investigación señala la importancia y uso del tajeo Mitchell como método de recuperación de los pilares minerales, dejados entre los tajeos de cuadra ya explotados en las zonas mineras. Históricamente el sistema data de 1904 y fue empleado en combinación con el tajeo de escuadras durante un tiempo, siendo posteriormente reemplazado por métodos más económicos como el hundimiento. Actualmente está limitado a la recuperación de pilares. Para sus aplicaciones se utiliza el stoping, como método de extracción de los minerales, donde los stopes se explotan para luego rellenarlos, dejando un acceso libre para los pilares. Una vez extraídos, se colocan puntales largos de extremo a extremo y se los rellena compartimento por compartimento a medida que se los explota. De otro lado, aunque el tajo Mitchell considere riesgos de seguridad por la vulnerabilidad del terreno, la ventaja radica es que es un método flexible que permite adaptarse a las variaciones de anchura del pilar y en el que su uso se limita cuando no sea posible la utilización de otro método.

Jul 20, 1955

By Dallas Bienhoff

Boeing Study Team Participants Andrew Daga & Associates American Aerospace Advisors Hamilton Sundstrand Harris Honeywell ILC Dover Lunar Transportation Systems Oceaneering Orion Propulsion SICSA Thin Red Line USA LSSCA BAA Topic 2: MFHE Definition Minimum Functionality Habitation Element Deployable Habitat DHE Update The Path to Growth

May 1, 2013

By V. G. Papangelakis, G. A. Moldoveanu

"One of the major commercially viable secondary sources of rare earths elements (REE) are the ion-adsorption ores, containing 0.05-0.3 wt% rare earth oxides physically adsorbed on the surface of clay minerals formed during weathering of lanthanide-rich rocks. Although ion-adsorption deposits are substantially lower grade than other types of rare earth sources, this is offset by the easier mining and processing costs and the low content of radioactive elements. The conventional extraction route involves ion exchange leaching with monovalent cation solutions (usually ammonium sulphate) under ambient conditions; during the process, the lanthanides are desorbed and transferred into solution, being replaced by the exchange cation. While ammonium ions are known to perform best, there is increased environmental motivation to investigate alternative lixiviants in order to minimize ammonium sulphate impact via reducing its use without considerable loss in rare earth recovery.The objective of the present research was to screen various cations salts (alkaline and alkalineearth metals present as sulphates, chlorides and acetates, respectively) in order to comparatively evaluate lanthanide desorption levels and provide a theoretical base of the observed behaviour. The overall aim is to gain a better understanding of how both cation and anion may affect the overall REE recovery from ores in order to provide alternative processing routes. The distinct exchange capabilities of cations were explained in terms of differences in cation hydration enthalpy within the same group, i.e. Cs+ > NH4 + > K+ > Na+ > Li+ and Ba2+ > Ca2+ > Mg2+. For the same cation, it was determined that REE extraction efficiency follows the order sulphate > acetate > chloride, based on dissimilarities in constants of formation values. Various process implications scenarios will be described based on using mixed cations and anion matrices."

Jan 1, 2016

By G. W. Jones

THIS paper describes experiments in which eight test samples of gelatin dynamite were fired in three different types of apparatus and the quantity and composition of the gaseous products of detonation determined. The special dynamites were so prepared that the oxygen balance of the samples varied from -35.0 to +6.0 g. per 100 g. of explosive, including the wrapper. By means of this graded series of explosives, the relation between oxygen balance and gaseous products of detonation could be studied explicitly. The effect of varying oxygen balance on explosive strength has been discussed in another paper.1 The apparatus employed in the work described in the present paper included (1) the Bichel gage, a steel bomb of 15-1. volume; (2) the Crawshaw-Jones confined detonation apparatus, a steel cannon from which the explosive is fired into a pipe of 90-1. volume; and (3) the Hercules tank, an apparatus in which the explosive is confined in a quartz block which is placed in a steel tank of about 4500-1. volume. A full description of the apparatus is given later. VARIABLES AFFECTING COMPOSITION OF DETONATION PRODUCTS The character of the detonation products of commercial explosives is governed in part by the same factors that affect the combustion products from explosive mixtures of air with gases or vapors. In either case, combustible materials-namely, carbon, hydrogen, and sometimes sulfur-are present and combined variously. In an exploding gas mixture the combustibles are oxidized by oxygen in the admixed air, whereas with explosives the necessary oxygen is provided by oxygen-carrying materials in the explosive ingredients.

Jan 1, 1928

By I. Mc Dougall

"The matte/slag tidal zone in a platinum smelting furnace is subject to severe process conditions which can often lead to premature failure of the lining. The MgO-FeO-Si02 slag is aggressive to refractory bricks, whilst the Ni-Cu-Fe-S matte is aggressive to water-cooled copper cooling elements, and can penetrate and sulphidize refractory bricks, particularly at the high matte temperatures often experienced in the PGM industry. A novel approach to the lining design was taken at Lonmin's new 10MW Furnace 2. An indirectly-cooled graphite ring was applied in the matte/slag tidal zone, with refractory bricks on the hot face. Thermal Finite Element modeling was conducted to determine the optimal lining design in this region of the furnace. The resistance of two graphite grades to damage by slag and matte was evaluated experimentally. The graphite lining is not wet by the matte, and is resistant to slag attack at operating temperatures. In comparison to water-cooled copper in various configurations, cooled graphite shows promise as an indirect refractory cooling system in the tidal zone area of furnaces.IntroductionIn South African Platinum Group Metals (PGM) smelting operations, the PGMs are associated with nickel-copper sulphides in magmatic rocks. After ore is mined, it is concentrated by means of a flotation process prior to smelting. Both rectangular 6-in-line and circular 3 electrode AC submerged arc furnaces are used for this purpose. A new 10 MW round furnace is currently under construction by Tenova Pyromet at Lonmin's Marikana Smelter Division. An overview of Lonmin's smelting operations and Lonmin's approach to smelting high chromite containing PGM concentrates is given by Eksteen et al. [1]"

Jan 1, 2012

By Matt Schuett

Antamina Mine Facts • Surface Water Design Principles • Drainage Areas • SEDCAD Modeling • Impacted Runoff Collection • Clean Runoff Collection • System Flexibility • Outfall Construction

May 1, 2004

Jan 1, 1999

By Hamblyn S

Oakbridge, in combination with its joint venture partner, Nippon Steel of Japan, is expanding its Bulga underground and open cut mines to meet the growing demand for coal in the Asian market. Expansion works underway will see the Bulga underground mine become a world leader in underground productivity, the introduction of a high capacity dragline into the open cut mine (largest capacity dragline in NSW) as well as a major upgrade of the coal preparation plant (CPP) and coal handling facilities (CHF) to process the increased production. This paper describes the planning and implementation of this major expansion program and highlights the rationale behind some key aspects of the program.

Jan 1, 1995

By W. A. Cole

Underground mining methods at the Gray mine of Tri-State Zinc, Inc., are of special interest because of the low unit costs achieved through use of jumbos and loading equipment mounted un crawler-type tracks and of diesel trucks that haul from the stoping areas to the mill through inclined adits. The operating company, Tri-State Zinc, Inc., is a wholly owned subsidiary of Gold Fields American Development Co., Ltd., the latter being the American branch of New Consolidated Gold Fields, Ltd., a British-owned company.

Jan 1, 1957

By Mendoza F. Juan

En las últimas décadas, la minería subterránea ha optado por el uso del equipo mecanizado Trackless o minería sin rieles. Dado su alto costo, se ha previsto establecer un sistema de control que mida la productividad y así definir las causas de su bajo o alta rendimiento. En esta perspectiva, el presente trabajo señala el cálculo de probabilidades y uso del equipo en el interior y exterior de las unidades de producción de CENTROMIN-PERÚ, definiendo cada uno de los términos y determinando la fórmula de los cálculos para estructurar el sistema uniforme en la empresa.

Nov 8, 1984

By William C. Browning

An economic drilling programme is one which costs the !east in chemicals, equipment, and time. The basis for such a programme with rotary drilling techniques is a drilling fluid in which bentonites do not swell. This is recognized in the growing trend toward gyp and other inhibited mud systems. Therefore, even though the mechanism of thinner action is a subject of applied colloid ,chemistry, the understanding of this mechanism is of economic importance in controlling the flow properties of inhibited muds. In phosphate, or sodium tannate, conditioned muds that are relative-!y free of contaminating-electrolytes, the thinner, or dispersing agent, is adsor.bed, ?creating an electrical double layer about the clay particles. The mutual repulsion of these charged particles effects colloidal stabilization, or deflocculation of the suspended clays, as discussed by Norton and others. In inhibited muds, however, the electrolyte concentration in the filtrate is sufficient to collapse the double layer and flocculation of the mud solids occurs, as evidenced by increased viscosity and gel values. Chemicals to control the flow properties of inhibited muds, therefore, are vital to the successful use of these systems as it is not always economical to adjust flow properties by watering back. Flocculation of suspended particles, as indicated in the work of Vervey, Overbeek, and others, is due primarily to gravity-like, long-range Van der Waals forces. Prevention of flocculation may, therefore, be secured by the interposition of any barrier between the particles, the thickness of which approximates the extension of the Van der Waals at-traction. Organic polyelectrolytes, such as Kembreak, Rayf!o, and Q-Broxin, may act to increase the double layer charge when used in small amounts in fresh-water muds. More important, however, is the fact that in inhibited muds an increase in concentration of the polyelecholyte permits the formation of a condensed film adsorption layer of the polyelectrolyte about the clay particle. When this occurs, the extremely viscous condensed adsorption layer creates a mechanical. barrier that prevents flocculation of clays, even in the presence of inhibiting concentrations of elecholytes. Rheological evaluation of the degree of deflocculation, or colloidal stability, may be made by utilizing the known effects of particle inter-action and volume concentration on the flow properties of suspensions. Rheological evaluation should be supplemented by direct microscopic or ultra-microscopic observation.

Jan 1, 1958

ALABAMA Anniston.-Bretz, J. A. Carrington, F. G. Gerber, A. B. Klugh, B. G. Semple, R. A. Ashland.-Barton, .J. Bessemer.-Abbott, C. E'. Ball, T. L. Beaver, J. J. Ferguson, V. Salmon, H. S. Sehaber, C. F. Whatley, W. J.

Jan 1, 1923

By William C. McBee

Prompted by forecasts of a sulfur oversupply, the Bureau of Mines, U.S. Department of the Interior, is conducting research on potentially large-scale uses of this commodity to extend or replace such construction materials as asphalt, cement, and mineral aggregates. Through these efforts, paving materials have been developed in which sulfur replaces up to 50 pct of the asphalt normally present and which can be prepared and placed with existing mixing and paving equipment. Laboratory properties and design methods for this direct mixing process are described along with properties obtained on small-and large-scale field demonstration projects. These properties are compared with those obtained from control materials prepared without sulfur additions. Monitoring for toxic gases during laboratory and commercial mixing and paving operations is discussed also.

Jan 1, 1978

The first mining in Western Australia probably commenced some 40 000 years ago when Aborigines arrived and began quarrying stone for tools and weapons, and ochre for decoration. The earliest documented mining by European settlers took place in 1850 on a small lead vein in the bed of the Murchison River, reported by the explorer A C Gregory. However, it was the discovery of gold in the Kimberley region in 1885 that first drew wider attention to the State's mineral potential.

Jan 1, 1992

By Pilkington T, Noy A

The Yallourn North Extension (YNX) open cut mine ceased mining operations in early 1989. YNX may be used again for coal supply at the discretion of the Coal Corporation Of Victoria (CCV); this has resulted in the need for interim rehabilitation of the site which may last many years, or indeed, permanently.The site has suffered substantial surface erosion over the years with large areas of bare clay and coal batters remaining exposed. The first priority is to reduce the quantity and improve the quality of stormwater runoff from the site. This is best achieved by appropriate revegetation and the use of existing landform depressions as silt trap/wetland areas. Proposed rehabilitation needed to take into account the sensitive fire safety of the open cut and the option to re-open the mine if CCV deems appropriate.The authors detail the factors involved in the rehabilitation proposal and the multi-disciplinary approach to planning including engineers, scientists, a forester, landscape architects and community input. The rehabilitation design included early consideration of land use and ongoing maintenance issues linked to water quality improvement factors including vegetation. Engineering input was required for reshaping and clay covering exposed coal batters and the design of silt traps which will revert to wetlands in future. The integration of each discipline has produced a rehabilitation design pleasing to both the SECV and community alike.

Jan 1, 1992

By Yao Dun-Pu

Solution mining, sometimes also refered to as chemical mining or bacterial mining, is an innovative technology which, by making use of proper chemical reagents and taking advantage of bio-chemical action of some micro-organism species, can dissolve effectively most. desirable metallic values from ores and then extract them profitably from the resultant metal-bearing solution by suitable means to form the metal product it is more preferable to the conventional mining methods, not only because of its capability to improve working conditions and minimize environmental problems either underground or on surface, but also for its amenability in particular, to exploit low-grade or submarginal ore bodies, or those deposits which are too deep-seated to be mined out economically. Furthermore, it also provides a potential approach to win metals directly from their ores or ore-deposits in-situ by more simplified methods and at a lower cast than the conventional mining-milling-smelting process would do previously. Hence, in developing countries such as China, it will most, probably become a new mining tool of great promise. (1)

Jan 1, 1981