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By H. D. Kline

This publication describes methods and techniques of mining and crushing limestone at 3 of 11 small quarries operated by Anderson-Oxandale Rock Co. in northeast Kansas in 1959. It is one of a series of reports by the Bureau of Mines on methods and costs of mining in various mining districts in the United States. The three quarries selected for study -Bosse quarry, Pottawatomie County; Hansen quarry, Morris County; and Huston quarry, Dickinson County (fig. 1) -were in many respects similar to many others that had been developed solely to fill local and usually transitory demands for crushed limestone for use as concrete aggregate, roadstone, and soil conditioning. Factors governing the choice of quarry sites were quality of limestone, shallow overburden, and proximity to points of consumption of the crushed stone.

Jan 1, 1962

By D. Kwietnewski

The 4th bore of the Caldecott Tunnel is a 50-ft horseshoe shaped highway tunnel located in the hills east of Oakland, California. Tunnel excavation was mostly completed using one of the world?s largest commercially available roadheaders, a Wirth T3.20. The geologic profile included seven different geologic units, which displayed a range of different behavior with regard to excavation and initial support. Following a brief introduction to the excavation and support methods, this paper will discuss roadheader performance in the various geologic units encountered during excavation. Comments will also be made concerning the relationship between the roadheader method of excavation and observed ground convergence during excavation.

Feb 27, 2013

Results of flotation tests on lead-zinc ore from Broken Hill, N.S.W., confirmed that flotation at pH 9 in the presence of cement gave poorer metallurgical results than flotation at pH 7. Additions of 2 kg/tonne wood raspings [e.g. blackbutt (Eucalyptus pilularis), blue gum (E. saligna), brushbox (Tristania conferta), or turpentine gum (Syncarpia laurifolia)l had little effect at pH 7 but greatly accentuated the deleterious effect of cement at pH 9. This was shown to be caused by e:xtractives (e.g. polyphenols and carbohydrate materials) derived from woods at pH 9. The proportion of extractives, as shown by DV absorbance spectra, increased with increase of pH and was affected by various salts.Additions of 1 kg/tonne Al2(S04)3.16H20 when cement or cement and wood were present showed that metallurgical results obtained by flotation were then very simHar to those in the absence of cement or wood or both. This was ascribed to lower pH values in the presence of aluminium sulphate and possibly to specific chemical effects.Additions of aluminium sulphate appear to offer an economic solution to the problem of treatment of ores contaminated with cemented fill at Broken Hill.

Jan 1, 1974

By Pedro Hugo Tumialán

El presente texto describe el proceso de mineralización de la mina Farallón, la cual está ubicada en la provincia de Huarochirí, Lima. Este yacimiento polimetálico produce principalmente zinc, cobre, plomo, plata, oro, donde la longitud total inclinada de mineralización es de 600 m. Asimismo, la silificación se da en toda la roca con rasgos de caolinización, sericitización y propilitización de menor temperatura y la mayor área mineralizada se encuentra en el intrusivo, en menor proporción por el lado volcánico.

Apr 1, 1991

By Jeffrey Shawn Peterson

The testing procedures of the U.S. Mine Safety and Health Administration specify that intrinsic safety acceptance tests be conducted using a standard tungsten-cadmium electrode configuration in the break- flash apparatus. However, in realistic mining environments, other materials may be more likely sources of sparking. Information defining the probability of spark ignition between common materials such as aluminum, brass, copper, lead, tin, cold-rolled steel, and stainless steel is of more practical value in determining ignition hazards. The U.S. Bureau of Mines has completed an investigation of the influence of material on the ignition probability using the breakflash apparatus. By comparing ignition currents or ignition voltages corresponding to a probability of one ignition per thousand sparks to those found previously for cadmium, a margin of safety may be estimated for each material. This report presents the results of an investigation into the influence of disk electrode material on the probability of ignition.

Jan 1, 2002

By Carl Lubbe, Ron Frye

Numerous articles have been written regarding the effects of blast control plugs in an attempt to quantify stemming ejection rates, air overpressures, fragmentation’and other parameters measured using these devices. In an effort to further attempt to understand the function of these devices, field and laboratory research conducted with various stemming devices was performed to enhance existing data sets and analyze otherphenomena that occur when these products are used.

Jan 1, 1998

By A. H. A. Robinson

Until quite recently-practically up to the present time-all but an insignificant amount of the copper produced in Canada was shipped abroad in the form of ore, matte, blister, etc., there to undergo the further treatment necessary to bring it to the refined state in which it is required by fabricators of copper. Consequently, Canadian manufacturers were forced to import nearly all the copper required in their business; and a considerable portion of the ultimate value to be derived from a Canadian raw material was lost to the country of its origin. In the early days of Canadian copper mining, when both the production and consumption of copper in Canada were much smaller than now, such a condition of affairs was perhaps economically unavoidable, and, in any case, was not a matte~ of sufficient importance to attract general attention. Later on, however, when there had been large and rapid increases both in the production and consumption of copper in Canada, it formed the basis of much adverse criticism, deserved or not, of producers of Canadian copper-criticism that became intensified during the war and subsequent years. Happily, the chief grounds of complaint have now been removed, and there are today copper refineries in Canada, either operating or under construction, that are capable, in the aggregate, of turning out amounts of refined copper greatly in excess of any indicated Canadian consumption.

Jan 1, 1931

By J. C. Johnson, W. G. Pariseau, D. F. Scott, F. M. Jenkins

In situ stresses are important input data for the design of safe, stable stope layouts and extraction sequences. However, it is commonly assumed that normal and shear stress gradients in a stress field are negligible and, consequently, that stresses are uniform throughout the region of analysis. To evaluate these assumptions and to provide input data for an analysis of a shaft pillar mining plan, in situ stresses were measured at the Homestake Mine, Lead, SD, using overcoring on hollow inclusion cells and borehole deformation gauges. These measurements were used with conventional least squares, best fit data reduction schemes. The results showed that normal stresses within the shaft pillar were less than, but comparable to, those estimated from finite-element modeling. Shear stresses were an order of magnitude less than normal stresses and varied considerably from site to site. Possible causes of this variability include effects of scale, elastic moduli, anisotropy, and axial strain. Because of the variability, it is not possible to determine the magnitude of horizontal stress gradients.

Jan 1, 1993

By Junji Shibata

Keywords: Synergistic effect, Solvent extraction, Nickel ion, extractant mixture Waste solution from the Ni non-electric plating process contains 4.0 kg/m3 Ni (II), 0.1 kg/m3 Fe (III), 0.01 kg/m3 Zn (II), 48 kg/m3 SO42-, 98 kg/m3 HPO32- and 31 kg/m3 lactic acid as a typical composition. Solvent extraction, cementation, ion exchange resin and precipitation methods may be used for the treatment of this kind of solution. In this study, solvent extraction of Ni (II) is investigated by using two kinds of extractants in order to clarify the relationship between extraction equilibrium (static synergistic effect) and extraction rate (dynamic synergistic effect) for several extractant mixtures. The static synergistic effect does not take place significantly for the extractant mixtures of acidic extractants and neutral organphosphorous compounds, while a large static synergistic effect is confirmed when the extractant mixtures of acidic extractants and nitrogen-containing compounds are used. Nickel ions can be extracted in the wide pH range of 3.0-8.0 without any pH adjustment by using the several extractant mixtures. At the same time, the extraction rate remarkably increases by using the extractant mixtures of acidic extractants and nitrogen-containing compounds.

Jan 1, 2005

By Lucas Barcelos Dias

A demanda por materiais ecológicos vem crescendo exponencialmente nos últimos anos. O potencial destes produtos é dado tanto pela versatilidade em seu uso quanto pela sua disponibilidade na natureza. Um dos materiais em expansão é o OSB (Oriented Strand Board), utilizado na vedação do Steel Frame. O trabalho tem como objetivo substituir em três porcentagens 15%, 30%, 45% das tiras de madeira do OSB convencional pela fibra do epicarpo do coco de babaçu (FECB), a fim de melhorar a resistência mecânica. Os resultados obtidos na chapa de 11 mm incorporada com FECB apresentaram resistência a tração entre 15 e 26 MPa e de flexão entre 42 e 75 MPa, tornando assim superiores ao produto encontrado no mercado.

Oct 30, 2017

By F. Weinberg, L. MacAulay

DAVIS,' in an investigation of solute redistribution along molten rods of dilute silver in tin, concluded that at horizontal temperature gradients below approximately 5°C per cm very little convective mixing takes place. Cole and winegard2 observed temperature oscillations in horizontal melts of tin, with temperature gradients of several deg per cm. They associated the temperature oscillations with the presence of convective flow in the melt. At temperature gradients less than 1°C per cm they did not detect convective flow. In the present work, direct measurements of con-vective flow in liquid tin have been made using a radioactive tracer technique. The results indicate that extensive convective flow occurs at temperature gradients below those previously reported. The apparatus used to determine the extent of con-vective flow is shown in Fig. 1. The graphite boat Fig. l(a), has two rectangular channels both of which contain molten tin. Radioactive Ag110 in the form of Sn-0.2 pct Ag alloy was introduced at the end of one channel, by rotating the cylinder shown. A series of fixed thermocouples were positioned along the center of the second channel to determine the temperature gradient. It was assumed that the two channels had identical temperature distributions. The graphite boat was inserted into a vycor tube which was surrounded by a multiple winding tube furnace as shown in Fig. l(b). The tin was melted in an argon atmosphere. The distribution of Ag110, as a function of position along the boat at a given time after introduction of the ~g"', was determined with the

Jan 1, 1970

By Li Jiuping, Zhong Gang, Chen Yong Zhang, I. Michael Gowring

The Liaoning Dahuofang Reservoir Water Transfer Project is an important development for the Department of Water Resources of Liaoning Province in northeastern China. The 85.3 km water conduit will transport water from the Hun River downstream of the Huanren Reservoir to the outlet on the Suzi River leading to the Dahuofang Reservoir. The additional water is required to sustain the growing cities of Fushun, Shen-yang, Liaoyang, Anshan, Panjin and Yingkou. The project is divided into seven contracts. Three TBM contracts comprise almost 75% of the work and the others are drill and shoot. The focus of this paper is about the creditable TBM performances achieved and some of the problems encountered by Chinese contractors; notably two having had no previous TBM experience.

Jan 1, 2007

By Ángel Chávez Mendoza

El presente texto describe el desarrollo de los Estudios de Impacto Ambiental y participación ciudadana, la base legal y experiencias realizadas en la minería peruana. También, se revisa los artículos que comprenden cateo y prospección, comercialización, lexploración y explotación, beneficio, la regulación ambiental 2016 y los pormenores de la participación de la ciudadanía y mesas de diálogo.

Aug 1, 2016

By Rodrigo Zambra

El presente texto señala las funciones del geólogo minero moderno -en tanto aporte al sistema de control y pueda registrar las observaciones sobre geología y otros aspectos de la mina. En ese sentido, los cambios más importantes son: Base de datos digital, uso de un programa GMP para procesar e interpretar datos de ensayos, determinación de ensayos en mayor volumen y a menor costo y mayor inspección de la productividad

Oct 1, 2014

By C. J. Brown

"Access to the outside world is supplied by the Alaska Highway to continental Canada and the United States, the Haines Highway, and by the White Pass & Yukon Route to Skagway and Vancouver. Communities and mining developments located along the Alaska Highway are supplied daily by truck transport with commodities originating in Whitehorse, Edmonton, and Vancouver.The average payload on the Alaska and Mayo Highway is in the order of 16 to 25 tons and is subject to government regulations. Highway haulage distances to railhead at Whitehorse vary as does the direction. The Clinton Creek asbestos development is located 395 road miles north-west of Whitehorse whereas the United Keno Hill operation is 287 miles to the north. Cassiar Asbestos is located in Northern British Columbia at a distance of 357 miles south-east of railhead at Whitehorse. In order to service these various mines multipurpose highway vehicles have been designed to allow maximum backhaul of petroleum products. The White Pass & Yukon Route was established as an integrated transportation system from 1955 when it became apparent that three non-integrated systems (ship, rail and truck), with the various paper work and rising costs, could not continue to serve the needs of Yukon. Integration became the company policy and a system was developed. A special container ship (Clifford J. Rogers) was designed and built. This was the first specially built container ship in the world. The northern container integrated system was operational in 1955.In 1965 over 8.5 million dollars were spent in upgrading the container facility and the construction of a tanker-container ship designed specifically to serve Yukon and Northern B.C. This program was based largely on experience gained with the original container concept. Two tanker-container ships handled"

Jan 1, 1973

By N. A. Gokeen, M. Ohtani

EFFECT of elements on the solubility of carbon in liquid iron is useful in calculating and correlating a number of thermodynamic properties as shown elsewhere in detail.' Kitchener, Bockris, and spratt2, and later Turkdogan and Hancock3 have investigated the effect of sulfur on the solubility of carbon at various temperatures and concentrations. For any chosen sulfur concentration, the solubility of carbon reported by Kitchener et al. is considerably lower than that by Turkdogan and Hancock. It was therefore felt that a reinvestigation of this problem was necessary. EXPERIMENTAL METHOD An alloy of Fe-C-S .was prepared with electrolytic iron and ferrous sulfide melted by induction in a graphite crucible, 4 in. high 1 1/2 in. ID under a CO-atmosphere. The temperature, held at 1500" ± 5°C in all experiments, was measured with a Pt-Pt + 10 pct Rh thermocouple immersed into the melt. In order to assure saturation with carbon, the melt was stirred with a graphite rod. After approximately 1 hr at 1500 °C, a sample was obtained by sucking the melt into a silica tube, 4 mm ID. The sample was then analyzed for carbon and sulfur by usual methods. RESULTS The results are presented in Table I and plotted in Fig. 1 with the individual values of Turkdogan and Hancock.3 Scattering in the data is equivalent to 3 pct or less in carbon analysis. The broken line represents the empirical equation obtained by Kitchener et al. from their data. It is evident that the present data are in good agreement with those of the former investigators but in disagreement with the latter. The cause for this discrepancy cannot be readily offered since the experimental methods in the three investigations were nearly identical. Additional evidence corroborating the author's results may be presented in the following manner. The difference between the solubilities of carbon in the ternary Fe-C-X melt with a small concentration of any element X, and in the binary Fe-C melt is %?C = %CIII-%CII [1] where %?C is the change in solubility, and %CIII and %CII are the solubilities in the ternary and the binary systems respectively. The value of %Cii

Jan 1, 1961

By William L. Crentz

In the past, Westmoreland County together with Fayette County produced about one-third of the bituminous coal mined in Pennsylvania. The Pittsburgh bed in Westmoreland County has furnished enormous quantities of coal to the by-product and beehive ovens, gas-manufacturing plants, and general industrial manufacturers over a wide area until about 20 years ago. Little attention was paid to the thinner beds because of the superior quality of the Pittsburgh. The approaching exhaustion of Pittsburgh coal will require accelerated-exploitation of these coals if Westmoreland County is to continue as an important source of bituminous coal, Much of the Pittsburgh coal in Westmoreland County is low-sulfur and requires no mechanical cleaning for the preparation of a metallurgical fuel. Even those areas where the sulfur percentage increased to a maximum of about 2 percent, a relatively easy washing operation usually produced a cleaned coal, which found ready acceptance by the coke industry. Davis reported the remaining recoverable reserves of the .Pittsburgh bed in Westmoreland County to be 255,439,000 tons as of January 1, 1937. Since that date, more than 100,000,000 tons of Pittsburgh coal has been extracted so that the time is not too distant when this important coal bed will be depleted. A study of the Pittsburgh bed in Westmoreland -County has not been made a part of this report as the remaining reserves of the coal can be used in coke making with a, minimum of preparation. The production from the Upper 'Freeport bed will increase as the supply of coal from the Pittsburgh bed diminishes, and as of the present time it supplies a substantial proportion of the county's coal output.

Jan 1, 1951

By C. Taschereau, G. A. Vickell, A. R. Laplante

Evidence in support of an iron-gold corrosion cell during the high-temperature/highpressure elution of loaded carbon is presented herein including, but not limited to, its discovery, mode of genesis, and confirmatory laboratory testwork. A discussion of metallurgical and economic impacts, remedial investigations, plant design considerations, and future work including mitigative possibilities is presented.

Jan 1, 2006

By James S. Graham

Specifications for treated round wood piling are presented for the engineers consideration. Included in the text are background information, technical committees, Chellis, quality, treatment, static and dynamic stresses, accessories, and existing codes and standards. The specifications are also available using Word Perfect on 3.5 or 5.25 inch size disks provided by the National Timber Piling Council. Note: DFI recommended wording is wood, head, and toe, instead of timber, butt, and tip.

Jan 1, 1992

By Wolf-R. Under

For improvement of urban traffic infrastructure, the City of Amsterdam is cur­rently constructing the 9.5 km long North-South Metro line passing through the central districts of Amsterdam. Focal section of the project is the Central Station linking the NS Line with the Central Railway Station, the East Metro line, new bus and tramway terminals, ferries and individual traffic. Construction works required for the project are of high complexity and technical standards. They are executed under severe restrictions concerning programming, space, logistics, and impact on the integrity of existing buildings and structures as all existing installations and facilities have to maintain fully operational during the construction period. The paper deals with the main geotechnical features of the project and in particular with the diaphragm wall and bored pile construction at the Voor-plein and the De Ruijterkade sections of the Central Station.

Jan 1, 2006