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The New Zealand Steel Ironsand Slurry Pipeline was successfully commissioned in February 1986. The project includes 18 km of high pressure, polyurethane lined buried pipe. McConnell Dowell Constructors Limited has developed a coupling which has allowed this pipeline to be fully welded. The design and development of the coupling and its application on this project is discussed.

Jan 1, 1986

A geologic, petrographic and geochemical study has been performed on the pyroclastic flow deposits in the coastal area of East Zhejiang Province, Southeast China. This study leads to classification of the pyroclastic flow deposits into three associations: the extrusive type, the surge type and the ash flow type welded tuff associations. Through detailed investigation and comparison of the characteristics of these lithologic associations, with emphasis on the welded tuffs, a comprehensive model has been proposed to demonstrate the petrogenesis of the pyroclastic flow deposits.

Jan 1, 1995

By E. O. Abrokwah

Directionally solidified (DS) Rene 80 Superalloy was tested in thermo-mechanical fatigue (TMF) over the temperature range 500-900°C and plastic strain levels from 0.2 to 0.8% using a DSI Gleeble thermal simulator. Thermo-mechanical testing was carried out on the parent material in the conventional solution treated and aged condition (STA), as well as gas tungsten arc welded with an IN-738 filler, followed by solution treatment and ageing. Comparison of the base TMF unwelded alloy with that of the welded and heat treated alloy showed that varying crack initiation mechanisms, notably oxidation either by stress assisted grain boundary oxidation, or associated with grain boundary MC carbides fatigue crack propagation along grain boundaries and creep deformation were operating, leading to different "weakest link" failure initiation points.

Jan 1, 2011

By G. S. Camm

Gwynfynydd is a small, high-grade black shale-hosted vein-gold deposit. The Chidlaw Link Zone is the only area being mined and contains 24 000 t ore grading 15.2 g/t gold. Within the Link Zone a complex vein structure occurs consisting of a mother vein up to 5 m thick and narrow (less than 0.5 m) leader veins. The former shows minor variations in dip, strike and thickness, whereas the latter show marked changes in all three. The leader veins are hosted within the footwall zone of the mother vein and both are composed of quartz with galena, sphalerite, chalcopyrite, pyrite and minor arsenopyrite. The vein system is transected by a series of cross-vein and intra-vein dip-slip faults. Pockets of gold occur at vein intersections or branches and within the complex footwall zone and are often related to variations in vein attitude and/or geometry. The Chidlaw Link Zone displays a complex, erratic distribution of gold mineralisation and a multi-stage history of structural activity, fluid flow and mineral deposition

Jun 18, 1905

By Edward Walter

Rock excavation for tunneling projects occurs on a regular basis in the Cleveland area. These tunnels are being constructed to increase the capacity of the sanitary sewer system. Controlled blasting must be performed to remove rock in a number of phases of the project. The rock excavation for construction of a junction chamber is just one case where blasting is the safest and most efficient method available.

Jan 1, 2001

By D. Olsen, S. Cole, J. Strid, G. Colzani

This paper focuses on the underground tunnel work at the Hollywood Water Quality Improvement Project (HWQIP) in Los Angeles, CA. The HWQIP is being constructed to provide a water distribution system to bypass the existing Hollywood Reservoir System, which supplies drinking water for 500,000 people. The major project features include, a 2.9-meter diameter 1,829 meter long bypass tunnel, a 1.8-meterdiameter 366 meter long utility tunnel, 3 jack and bore tunnels, two 136 million liters underground circumferentially wrapped pre-stressed concrete water storage tanks, associated piping, and mechanical facilities. The physical project location coupled with strong community involvement and stringent environmental concerns was a considerable driving force for this project located in the Cahuenga Pass area of the Hollywood Hills north of Los Angeles, CA.

Jan 1, 2001

By M. Felsenthal

Engineers are frequently faced with the problem of having to predict oil recovery from a solution gas drive reservoir in the early life of a field. This is often the time when actual laboratory or field-derived gas-oil permeability (kg/k0) data are not yet available. Although excellent collections of k0/k0 data for various types of rocks may be found in the literature,1,2,3 a need exists for a more detailed correlation of k0/k0 data with core properties such as porosity, permeability, clay content or pore-size distribution. It is the purpose of this article to present this type of correlation for sandstone material. The correlation is based on laboratory tests performed on over 300 core samples from 19 reservoirs in the United States and Canada. EXPERIMENTAL Cores were analyzed by routine procedures, using samples of conventional size (7/8-in. diameter, 7/8-in long) cut parallel to the bedding planes. Air permeability was measured at 1.67 atm mean pressure in a Hassler-type apparatus. Porosity was determined with the aid of a Ruska bulk volume meter and a Boyle's Law rock volume meter, An evaporation method' was used to evaluate irreducible water saturations. Core samples were saturated with 25,000 ppm NaCl brine. The brine was reduced to the irreducible saturation, and the remainder of the pore space was filled with kerosene. This was followed by multiphase flow tests using the so-called "dispersed feed" technique.5 n this technique, gas and oil (kerosene and kerosene-saturated air) were dispersed with the aid of a porous Alun-durn feed head, the face of which contained a waffle-shaped system of Lucite-lined grooves. Oil entered the back side of the feed head and emerged at the raised areas of the front face. Gas was introduced directly into the system of grooves at the front face. The gas-oil mixture then entered the test core which was kept in capillary contact with the feed head. Permeabilities were determined from rate and pressure measurements and saturations from weights. All determinations were performed at equilibrium or steady-state conditions. Pore-size distributions were determined on selected samples by a mercury injection technique.6 GENERAL CORRELATIVE TRENDS When examining data from a given reservoir, it was noted that k0/k0 vs saturation curves became generally less steep as specific air permeability increased, a development that has a favorable effect on oil displacement efficiency by solution gas drive. This trend has also been reported by others in the literature.' An effect of porosity on k0/k0 data was also noted. This effect was not generally discernible in a study of relative permeability data for a given reservoir but became apparent when data for sandstone reservoirs of similar lithology but differing average porosity were compared. For instance, in a comparison of argillaceous and/or calcareous sandstones from 11 reservoirs ranging in average porosities from 14 to 28 per cent, a definite trend was noted, indicating that for a given permeability k0/k0 curves became less favorable (i.e., steeper) as porosity increased. A similar trend was observed for a group of comparatively clean sandstones from five reservoirs ranging in average porosities from 15 to 21 per cent. For a given permeability and porosity, comparatively clean sandstones gave more favorable k0/k0 curves than argillaceous and/or calcareous sandstone or chert reservoirs. The laboratory studies also showed that least favorable k0/k0 curves were exhibited by shaly sandstone, conglomerate, and sandstone containing carbon inclusions. Table 1 lists the various source reservoirs classified by lithology types. To facilitate a correlation of k0/k0 data with core characteristcis, it was found expedient to work with

By Luis Espinoza

La unidad minera Tintaya al igual que la Unidad Minera Antapaccay, son las operaciones de la división Perú de Xstrata Copper dedicados a la producción y comercialización de concentrado y cátodos de cobre. Sin embargo, la mina está en su última etapa de vida. En este sentido, surge el proyecto de integración de la unidad Antapaccay, donde se busca prolongar la vida útil de la mina y por consiguiente, el de la actividad económica minera en la provincia de Espinar. Por ello, el presente trabajo, describe los efectos de esta expansión de la explotación minera a través de la Unidad Minera Antapaccay que utiliza las instalaciones de Tintaya, manteniendo los planes de inversión social y el desarrollo económico local y regional.

Sep 21, 2013

By A. Tor, M. Borowski, N. Szlazak, D. Obracaj

This article presents possibilities of reducing methane emission to the atmosphere in working mines in Jastrzebie Coal Company by means of proecological solution. They form a new approach towards the problem of rational and effective use of natural resources both in economical and environmental respect. Power and thermal energy for underground air conditioning in mining excavations are produced from the methane, which is drained out of the mine for safety reasons.

Jan 1, 2003

By D. M. Avant, S. M. Pickering

A variety of grades of very white muscovite mica are now being produced from sedimentary sands and clays in Central Georgia. The mica is naturally concentrated near the base of the lens-shaped kaolin deposits and also disseminated in associated quartz sands. The same weathering and bacterial alteration processes which have transformed the kaolins from dark organic muds to white pigment-grade industrial clays have also removed discoloring iron from the micas and developed unusually white muscovite. Further, chemical alteration has removed some potassium from the muscovite atomic structure, resulting in an easily delaminated mica which can be cleaved to unusually fine, high bulking, high aspect ratio products. The peculiar alteration history of these sedimentary micas enables production of some of the whitest, finest particle size, and thinnest aspect ratio muscovite mica products on the world market today. Raw mica feed is obtained from kaolin and sand processing by-products, and also from beneath the useful base of abandoned kaolin mines. The processed ultrafine and filler grade muscovite mica products are used for paint, plastics, cosmetics, mold release, thermal and electrical insulation, epoxy, and dry wall joint cement markets.

Jan 1, 2002

By E. D. Gardner

This is one of a series of paper's being published by the Bureau of Mines on placer mining; it is written as a supplement to Information Circular 6788, "Placer Mining in the Western United States, Part III", by E. D. Gardner and C. H. Johnson which was published in February 1935. Since Information Circular 6788 was written (1933), considerable advance has been made in the technique of mining placer gravels with power shovels and draglines. Although new washing plants continue to be built in accordance with untried designs the trend of new installations is toward proved equipment. A substantial number of plants are now being operated successfully (1937).

Jan 1, 1938

Jan 1, 1994

Probably no other country or coutinent has so many rich deposits of various different minerals as Australia. Long ago in the days of my boyhood in the old land the marvellous discoveries of high percentage copper at Burra Burra, Peak Downs, Yudanamutana, and other mines, was one of the principal themes of conversation in mining circles whilst the specimens of malachite, azurite, etc, brought home by returning miners were the admiration of my boyish eyes.Later on the WalIaroo and Moonta mines still further helped to heighten the reputation of Australia as a copper-producing country. During the 21 years that the writer has been resident in the Australian colonies, other mineral deposits have sprung into prominence, and with a Mount Bischoff for tin, a Broken Hill for silver and lead, and a Mount Morgan for gold, Australia can now boast that it has had within its borders the leading mines of the world, in four different minerals, and still at least maintains that pre-eminence in gold, silver and tin. To the miner from the old land, Australian mining is at first a revelation and a wonder. In very many instances he looks in vain for the regular strike and dip of the veins he has been accustomed to'Smooth hanging and foot alls are often wanting. 'Huge irregular deposits, like those mentioned above, viz., Burra Burra, Mount Bischoff, Broken Hill, and Mount Morgan, are mysteries that will take time to fathom-if, indeed, they are ever thoroughly understood and in many a smaller deposit there is much to interest alike the professor in the college and the miner in the mine.

The paper examines the value of very small-scale indigenous gold mining operations to developing countries. The paper looks particularly at this type of activity in two neighbouring countries, Papua New Guinea and the Philippines, considering technical, economic, social and environmental aspects.

Jan 1, 1990

By E Ah Mu and C R Lilley, A D. Campbell

Cave propagation is a complex process due to interacting variables such as mine geometry, rock mass heterogeneity and complex structural networks and stress fields. The Ernest Henry sublevel cave (SLC) is directly below an open pit, which provided an opportunity to observe and measure rock mass failure as the cave initiated and propagated through the pit wall. This paper describes interaction between the open pit and SLC as well as rock mass failure mechanisms observed from the start of the SLC to surface breakthrough.Cave propagation and slope failure mechanisms were found to be governed by intermediate structures, while the cave shape was largely controlled by cave-scale faults. The open pit, production-level geometry and production draw strategy were also important factors for cave and subsidence growth. Cave propagation was episodic and asymmetric in shape due to the orientation and relative position of geological structures, combined with the effects of the increasing SLC geometry and drawdown from the underlying production levels. The precursors and failure mechanism of a 2.5 Mt wall collapse are also reviewed in detail.Cave growth was simulated using a 3D, non-linear, discontinuum finite element model coupled with Newtonian Cellular Automata. Model results are compared to field observations and monitoring data to determine the accuracy of forecasts and compared models versus actual rock mass response during cave propagation.CITATION:Campbell, A D, Ah Mu, E and Lilley, C R, 2016. Cave propagation and open pit interaction at the Ernest Henry Mine, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 311–318 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

By AIME AIME

MANY interesting papers, opportunity of seeing o1d friends, and an exposition showing all that is latest in equipment, all were factors in bringing a large crowd to Detroit during "Metal Week," October 2-6. The Institute's Iron and Steel and Institute of Metals Divisions held technical sessions at the Statler Hotel on October 4 and 5, and that hotel was also headquarters for the American Society for Steel Treating and the American Society of Mechanical Engineers, both of which also had technical sessions. The American Welding Society and the Wire Association met at the Book-Cadillac Hotel, and the exposition was staged at Convention Hall, out Woodward Avenue. All in all it was a big week for men interested in metal working. One of them stated to your reporter on the train en route to Detroit that this was the one convention that he never missed, and doubtless others felt the same way about it.

Jan 1, 1933

By A. R. T. Denues

The Explosives Division of the Bureau of Mines, United States Department of the Interior, is investigating cushioned blasting at the Explosives Testing Station, Bruceton, Pa. The general interests of this investigation are practical and relate particularly to safety. The immediate concern is an application of cushioned blasting in coal mining In cushioned blasting, various means are employed to reduce the intensity of the application of energy in an explosive action in a borehole. The primary object is to increase the efficiency of the use of explosives.

Jan 1, 1940

By A. R. T. Denues

The Explosives Division of the Bureau of Mines, United States Department of the Interior, is investigating cushioned blasting at the Explosives Testing Station, Bruceton, Pa. The general interests of this investigation are practical and relate particularly to safety. The immediate concern is an application of cushioned blasting in coal mining. In cushioned blasting, various means are employed to reduce the intensity of the application of energy in an explosive action in a borehole. The primary object is to increase the efficiency of the use of explosives.

Jan 1, 1940

By John C. Machisak

INJURY and employment figures for nonmetal mines and mills in 1959 are presented in this publication. Data for nonmetal mines are presented separately from those for nonmetal mills. The Bureau of Mines is authorized to send questionnaires to the nonmetal mining industry each year requesting their voluntary submission of injury experience and employment data. The voluntary response to these requests has contributed greatly toward the promotion of safety in the industry, and every effort has been made to make the information as complete as possible.

Jan 1, 1963

By R. Bruce Patterson

The New Tacoma Narrows Bridge is a classic suspension bridge founded on concrete caissons. Caisson construction was complicated by the proximity of the existing bridge piers, only sixty feet away. High capacity plate anchors were used successfully to moor the new caissons in currents as strong as seven knots during construction.

Jan 1, 2004