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By Michael S. Miller

The U.S. Bureau of Mines (USBM) conducted mineral investigations in the 1,227,000-acre Emigrant Trail study area of Nevada during 1992. During the USBM investigation of 25 areas of development interest, 190 mineral localities were identified and 260 rock and 50 alluvial samples were taken. At least 0.5 million troy ounces of gold, 2.3 million troy ounces of silver, 3.3 million pounds of copper, 10.9 million pounds of lead, 2.4 million pounds of zinc, 500 tons of alunite, 40,000 tons of sulfur, 9,000 pounds of mercury, and 21,000 pounds of tin have been mined from the area and vicinity. Adjacent to the study area, gold is being mined at large, open-pit gold mines, the Hog Ranch and Hycroft Resources, Inc., Sulphur mines, and new production is planned at the Rosebud LAC/Equinox. Hog Ranch mine is nearing depletion, but resources of more than 0.5 million troy ounces of gold and about 5 million ounces of silver are estimated for the Rosebud LAC/Equinox project and more than 0.4 million ounces of gold for the Hycroft Resources, Inc., Sulphur mine. Significant investigations are occurring at SP Ridge and other sites near Scossa and at the Dan claims in the Southern Calico Mountains. Precious opal, placer gold, and geothermal energy resources occur in the study area and vicinity.

Jan 1, 1993

By D. J. Ketkar

It is a frequent experience to find that the Sub-surface Investigation (S.I.) data is either inadequate or misleading. However, such cases are rarely reported. Nonetheless, the projects suffer on-account of delays, cost-over-runs, disputes and/or compromise of the safety norms. Many times S.I. is considered unnecessary or is carried out as a ritual, mainly due to (i) non-availability of good S.I. agencies, or (ii) absence of Geotechnical consultant, or (iii) shortage of time. Importance of S.I. cannot be over emphasised. Yet the profession is in a state of confusion - mainly because of lack of competent professional agencies and of well-defined roles/responsibilities of the concerned parties. In this paper, some suggestions are made to get better returns from the S.I. activity.

Jan 1, 1996

Jan 1, 1967

By E. W. Engle

Fox several years the Fansteel Products Co. has been engaged in the production and development of various of the rarer metals. It is at present engaged in the commercial production of tantalum, tungsten, and molybdenum in a very high state of purity. The information contained in this paper is partly a general compilation from various sources and partly information obtained as a result of recent years of work in the laboratory of this company. Tantalum, tungsten, and molybdenum form a group peculiar to themselves among the commercially available metals. Their very high melting points (tantalum 2770° C., tungsten 3350° C., and molybdenum 2550° C.) set them apart so far as the metallurgical processes for their production are concerned. Further, when properly prepared and treated they will stand a somewhat unusual degree of cold work, that is work below the temperature at which marked crystal growth takes place. Such cold-worked metal may show a high tensile strength; tantalum to 130,000 lb. per sq. in., tungsten to 490,000 lb., and molybdenum to 260,000 lb., in the form of fine wire. In physical appearance, these metals are not unlike some steels; they may be better described by saying that polished tantalum some¬what resembles lead; polished tungsten, iron; and polished molybdenum, nickel. The polished surfaces of all three remain untarnished in ordinary air. Air containing corrosion-producing impurities will, in general, show molybdenum the least resistant to corrosion and tantalum the most resistant. Molybdenum has, however, a high degree of resistance to corrosion by hydrochloric acid, a property that should render it of commercial interest. On the other hand, it is markedly attacked by some of the weaker organic acids.

Jan 3, 1925

By H. H. McGregor

Introductory remarks by author When Mr R. C. J. Goode suggested preparation of a paper in the area of manpower utilization in South Africa, I was, while keen to accept his invitation, somewhat hesitant for two reasons. Firstly, I recognized the great difficulty of making a factual contribution, because of the lack of really relevant statistical information available, the fact that much of it is out of date, and the difficulty of researching and co-ordinating it and of evaluating a statistically sound resultant viewpoint. Experience in the actual preparation of this paper has done nothing to change my view in this respect. Secondly, it is obvious that a paper presented to a meeting of this Institute, by a member of it, would be expected to devote considerable attention to the subject in the mining industry. I am not directly employed by the mining industry, although my company has carried out extensive assignments for various sectors of it both in this country and in other parts of the world, since the 1939-45 war. I am more conscious than most of the tremendous technical and managerial skills at the disposal of the industry in this country, and consequently am equally conscious of the hazards of publishing facts and figures which might be taken to indicate any criticism of performance. I am aware that some of the information that I am about to present may indeed generate comment, and possibly even critical comment. I would like to be regarded therefore in presenting this information, as a member of the group, rather than an external critic. Under these circumstances, comment can only be constructive, and this is my earnest hope. The contribution of my paper, if contribution there is, will I hope be in the area of assessing labour productivity in mining, and in secondary industry in such a way that the performance of each against its own past results is comparable. This task has not for the present been to my knowledge attempted, and in advance I wish to take out authors' insurance against legitimate criticism from professional economists and others, by stating that I am well aware of possible short-comings in the arguments. Nevertheless I believe that under the circumstances I have, with the important assistance of several people, been able to take the subject further than has been the case in the past. Finally, I have related productivity in the mining industry and in secondary industry to a target of productivity in the Republic of South Africa. I was fortunate recently in being able to attend a series of lectures by a prominent economist in America. He introduced his subject by calling it 'A broad survey of macro-economics'. Perhaps I might be permitted to describe my paper, in the same idiom, as 'The macro-management of labour'.

Jan 6, 1970

By Bernard A. Grand, Gary A. Almeraris

This project involves the reconstruction of a 1,100 ft. long by 75 ft. wide segment of an existing 4 to 5 track subway under Northern Boulevard in the Borough of Queens in New York City. The project includes widening the existing subway to permit the construction of new inbound and outbound subway (T1 and T2) ramps adjacent to and under existing operating tracks. The plan of the project is shown in Fig. 1. Existing tall buildings along the job site and a contaminated groundwater plume under an adjacent rail yard required construction of slurry concrete walls along the east and west construction limits. Groundwater cutoff across the north and south construction limits of the subway was achieved by jet grout walls built across the subway invert slab between existing track and third rails. The work involved dewatering the construction site to a depth of about 50 ft. below street grade. This is a four year project and includes extensive work to maintain and protect subway and vehicular traffic of over half a million commuters a day through the work area. The project cost was $160,000,000.

Jan 1, 1999

By C Quirion

Agnico-Eagle Mines Limited, Laronde Division, operates the deepest single-lift shaft in the western hemisphere. The initial Penna hoisting plant was designed for a production rate of 1800 tonnes per day (t/d) from a 2240 m deep shaft. Exploration success, while sinking the shaft, led to a decision in 1998 to increase the production rate to 4500 t/d of ore from a loading depth of 2200 m. The new production rate was achieved by increasing the size of the rope and reducing the rope static factor from the existing 5.0 required by regulation to a static factor using the formula 25 000/(4000 + L) contained in a draft document that would eventually become SABS 0294 in South Africa. The formula permits Laronde to use a static factor as low as 4.0. The upgraded Penna hoisting system is the first hoisting plant outside of South Africa to meet the South African requirements. This paper describes the conversion of the hoisting plant to the lower rope selection factor in the year 2000 and the operating and maintenance issues experienced since then.

Jan 1, 2005

By Herbert Clark Hoover, Lou Henry Hoover

IN the last book I have explained the methods of delimiting- the meers along each kind of vein, and the duties of mine officials. In this book1 I will in like manner explain the principles of underground mining and the art of surveying. First then, I will proceed to deal with those matters which pertain to the former heading, since both the subject and methodical arrangement require it. And so I will describe first of all the digging of shafts, tunnels, and drifts on venae profundae; next I will discuss the good indications shown by canales2, by the materials which are dug out, and by the rocks ; then I will speak of the tools by which veins and rocks are broken down and excavated ; the method by which fire shatters the hard veins ; and further, of the machines with which water is drawn from the shafts and air is forced into deep shafts and long tunnels, for digging is impeded by the inrush of the former or the failure of the latter ; next I will deal with the two kinds of shafts, and with the making of them and of tunnels ; and finally, I will describe the method of mining venae dilatatae, venae cumulatae, and stringers.

Jan 1, 1950

By N. S. Dalal, A. H. Hoffman, X. Shi, D. E. Banks, J. K. H. Ma, Y. Rojanasakul

Excessive production of reactive oxygen radicals by alveolar macrophages is proposed to play an important role in oxidative lung injury. A major product of oxygen radical formation is the highly reactive hydroxyl radical (•OH) generated via a biologic Fenton reaction. In addition to its known ability to induce lipid peroxidation, recent studies have suggested that the •OH may exert its cytotoxic effect through the alteration of [Ca2+], homeostasis. To test this potential mechanism as well as to investigate the relationship between •OH and Ca" overloading in cytotoxic injury, isolated rat alveolar macrophages were exposed to externally generated radical system, H2O2 (0.01 to 1 mM) and Fe (1 mM) and their [Ca2+] levels and cell injury were monitored using quantitative fluorescence microscopy with the aid of the specific Ca" indicator, Fura-2, and membrane integrity indicator, propidium iodide. Electron spin resonance measurements using the spin trap 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) confirmed the production of the .OH radical by this system. Upon the addition of the radicals, the macrophages displayed a rapid initial rise in [Ca2+] which was followed by a slower but more pronounced [Ca2+], elevation that reached a level 3 to 5 times higher than the basal level. This process preceded cell death as evident by nuclear propidium iodide fluorescence. Depletion of extracellular Ca" inhibited both the [Ca2+], response and cell injury. Preincubation of the cells with the Ca" channel blocker verapamil or .0H radical scavenger mannitol similarly inhibited the [Ca2+], rise and loss of viability. Firefly luciferase assay of cellular ATP content demonstrated that the alterations in [Ca2+], following .0H treatment preceded the depletion of ATP. Changes in membrane potential caused by Na* substitution with K* had no significant effect on either the unstimulated or stimulated [Ca"], levels. Taken together, these measurements indicate that .OH-induced injury in alveolar macrophages is associated with the alteration in [Ca2+], homeostasis. The mechanism of •OH-induced [Ca2+] loading is not due to nonspecific membrane damage or energy depletion, but mainly due to an increase in Ca2+ influx through Ca2+ selective channels. This Ca2+ over-load state as well as energy depletion caused by the oxidant may activate certain cellular degradative processes leading to cell injury and death.

Nov 1, 1995

By Robert J. Whiteley, Colin Parker

Two major tunnel projects with a combined value of about $US700 million have been recently completed in Sydney using both soft ground and hard rock Tunnel Boring Machines. The first of these and the main entry in Australia for the Year 2000 Olympics was the New Southern Railway. This is 10 km of mainly soft ground tunnel linking the Sydney’s International Airport with the Central Business District. The second tunnel was designed to alleviate major stormwater pollution of Sydney Harbour and involved construction of the Northside Storage Tunnel. This is19 km of hard rock tunnel at depths exceeding 90 m that connects many of the northern Sydney suburbs of Sydney with the North Head Ocean Outfall. Case studies of these projects describe the use of innovative geophysical technologies comprising gravity and seismic tomographic imaging with geotechnical testing at the feasibility and design stages. This approach minimised construction and financial risk by effectively quantifying the significant geological and hydrogeological issues along these tunnel routes that exerted major controls on these projects.

Jan 1, 2001

SITUATED in the county of Manchcster, in Northern Eyre's Peninsula, the Iron Knob ore-deposits form the basis of the industry. These deposits are connected by the Iron Knob tramway to the port of Whyalla, aal miles distant, on the western shore of Speneer Gulf,and to-day another tramway is under construction to link up with the same port, a second group of iron ore leases known as Iron Baron, which is situated 18 miles south of Iron Knob. Fig. 1 indicates the geographical relationship of these three places, Iron Knob, Iron Baron, and Whyalla, which together comprise this field of the company's activities.

Jan 1, 1930

By Benj. Lyman

The Institute, in June, 1881, visited Low Moor in Alleghany County, Virginia, on the Chesapeake and Ohio Railway, seven miles easterly from Covington. Having occasion myself, a few days later, to make a very hasty geological reconnaissance of the iron-ores there, and finding them to be somewhat different in age from what was said to be the opinion of some of those who were there with the Institute, I have thought it worth while to bring the matter up again at the present meeting. According to the opinion quoted, the principal ore-banks belong to the Oriskany sandstone; and that seems to be the view entertained of the same ore in that region by Prof. Wm. B. Rogers in his reports of 1837 and 1838. it is likewise given by Prof. J. L. Campbell in a paper on the Rich-patch iron region in The Virginias for December, 1880 (vol. i., p. 189). A comparison, however, of the section at Low Moor with sections in Pennsylvania, shows clearly that the main ore-bed is the same as that of the bottom part of the Marcellus shales (part of Pa. and Va., No. VIII), a short distance above the top of the Oriskany sandstone (No. VII). The Upper Helderberg limestone is absent at Low Moor, as indeed it is at many places in Pennsylvania, and that is perhaps the reason why the ore has been thought to belong to the Oriskany sandstone. The ores and their accompanying rock-beds, are exposed in three or four folds near the Low Moor iron-mines on Fork Rim and, as described and pointed out by Mr. Geo. T. Wickes, who had in his management of several years' duration become well acquainted with them, are as follows, from above downwards:

Jan 1, 1886

[AARONSON, E.: Discussion on Recent Developments in Fractionation as Applied to Tube Still Distillation, G26, 418 Abbe. See Microscope. Abbe apertometer, 95, 16 ABBOTT, W. L.: A.S.M.E. president, M26,113 biography, M26,113 ABORN, R. H.: Discussions: on Effects of Columbium in Chromium-nickel Steels 113, 159 on Pure Iron and Allotropic Transformations 84, 342 on Prevention of Intergranular Corrosion, 100,329 ABORN, R. H. AND BAIN, E. C.: Discussion on Widmanstätten Structure in Ironcarbon Alloys 105, 252]

Jan 1, 1936

By C. T. Anderson

In July 1947, the U. S. Bureau of Mines, in cooperation with the Air Materiel Command, started an investigation of zirconium alloys with the object of determining the suitability of such alloys for high-temperature applications. This report covers the preliminary study of about 25 zirconium-rich alloy systems with respect to preparation, fabrication, tensile properties, metallographic structures; constitution, and heat resistance. Obviously, each system could not be investigated thoroughly, and this publication can be regarded only as a first approach. The more promising individual alloy systems will be studied in greater detail and reported in subsequent publications. The study of zirconium alloys on such a scale has been made possible by the U.S. Bureau of Mines developments in the past 5 years On producing zirconium metal. This basic process is similar to that developed by Kroll for producing ductile titanium metal and consists essentially of reducing zirconium chloride by means of molten magnesium. The Northwest Electrodevelopment Laboratory at Albany, Oreg., has produced several thousand pounds of ductile metal in this manner and has a pilot plant producing over 300 pounds of metal per week. Alloys were prepared by melting Bureau of Mines zirconium and the best available grade of alloying element in graphite, with suitable provisions for preventing oxidation. The ingots were quartered longitudinally and sheath-swaged at 850° c. to 3/8-inch diameter rod. Two of those rods were send to Wright Field for room-temperature and 1,200° F. tensile properties. The remaining two sections were used for metallographic, hardness, heat-treatment, and heat-resistance studies. The salient features of this investigation are summarized in table 1.

Jan 1, 1950

Schedule of Events

Jan 1, 1977

By A. C. Wingrove

The paper outlines the selection of a dewatered tailings backfill system for the Johannesburg Consolidated Investment Gold Division, and covers the following aspects: (i) 16 Shaft pilot testwork; (ii) engineering design problems relating to the Cooke 3 Shaft backfill operation; (iii) in-line mixing - applications with respect to the Randfontein Estates Gold Mine and Western Areas Gold Mine backfill operations; and (iv) pipeline friction losses.

Jan 1, 1988

By John S. Berber

Bureau of Mines research on the production of phthalic anhydride by vapor phase oxidation of hydrocarbons began at Morgantown, W. Va., in October 1960. For these preliminary studies, a known solution containing naphthalene and 1-methylnaphthalene was used. In another series of tests, pure naphthalene was dissolved in different solvents. A series of investigations was conducted with the neutral oil fraction (210° to 270° C) of a low-temperature tar obtained from the Texas Power and Light Company's low-temperature carbonization unit. The neutral oil fraction was first dealkylated, and then the product was distilled into 210° to 250° C and 250° to 270° C fractions. These two fractions were then subjected to catalytic vapor phase oxidation. Although a number of catalysts was tested, most of the experiments were made using 9 percent vanadium pentoxide on inert alumina. The activity of this catalyst did not decrease after 162 hours at 1,030° F. Studies were conducted over a temperature range from 610° to 1,180° F. An operating temperature of 1,030° F yielded 47.50 percent of phthalic anhydride from a synthetic mixture of naphthalene and 1-methylnaphthalene. The highest yield (84.40 percent phthalic anhydride) was obtained with naphthalene dissolved in toluene and also with naphthalene dissolved in methyl ethyl ketone. With a 210° to 250° C fraction the highest yield of phthalic anhydride obtained was 12.32 percent at a temperature of 900° F, and, with a 250° to 270° C fraction, it was 15.80 percent at a temperature of 875° F.

Jan 1, 1963

By Dennis Hoffmann

"Abstract - Banded iron formation rocks associated with massive sulfide lenses in the Broken Hill Pb-Zn-Cu-Ag deposit in the Namaqualand Metamorphic Complex, South Africa , were investigated with respect to the geochemistry of manganiferous silicate-rich bands. Two common varieties of these are: amphibole- and garnet-rich iron formation bands. The results reveal that the former are enriched in Fe, Mg, Cu, Co and S. The garnet-rich bands are enriched in Mn, Ca, P, Pb and Ba with significant detrital contamination of Ti, Al, Zr, Cr, Y, V, Ni and Nd.The silicate-rich bands have compositions, in terms of, Si/Al, Si/Fe, Fe/Mn, La/Ce and Co/Zn, comparable to submarine chemical sediments which precipitated from hydrothermal fluids. The garnet­ and amphibole-rich bands are interpreted as ""evolved"" and ""immature"" hydrothermal sediments, respectively. The latter resulted from rapid precipitation after exhalation, whereas the former had a longer residence within sea water. The silicate-rich bands both exhibit increasing Mn/(Mn+ Fe) fractions, which are consistent with a variation expected from proximal to distal depositional settings. The prevalence of garnet-rich bands over amphibole-rich bands is interpreted as the result of injection of hydrothermal fluids from a single vent situated along the northwest margin of the Broken Hill deposit."

Jan 1, 1994

By Yoji Imai, Akio Watanabe, Masakazu Mukaida

"To clarify the feasibility of alkoxides and acetylacetonates as precursors for laser CVD of metal oxides, vapors of tantalum or titanium alkoxides and zirconium acetylacetonate were irradiated by KrF excimer laser and deposits were characterized by XRD and XPS measurements. As for tantalum and titanium, non-stoichiometric crystalline oxides grew nearly phototropically, however, zirconium oxides deposited showed only halo-pattern by XRD measurements. Electric conductivity measurements of tantalum oxides implied the improvement of the insulating properties by the addition of activated oxygen to the ambient.IntroductionThere has been renewed increasing attention to the metallic oxide thin films because ofits promising usefulness in many applications, such as high-Tc superconductors and ferroelectric devices. A variety of thin film preparation techniques have been studied such as sputtering, chemical liquid deposition (sol-gel and metalorganic decomposition), pulsed laser deposition and chemical vapor deposition (CVD). Among them, we think CVD is the most promising method because it offers a high controllability of morphology and good step coverage at relatively high growth rate. Preparation of oxide films by CVD can be achieved using a precursor containing metallic element and oxygen containing gas such as N20 at the same time. However, metalorganic (MO) compounds which contain both metallic element and oxygen, directly bonded to metallic element, seems to be more favorable because some of MO has a good properties for CVD such as a rather high vapor pressure, stability in ambient and low toxicity."

Jan 1, 1998

By V. R. Garfias

Although the work on which this paper is based was carried on by the writer as Special Commissioner of the Petroleum Department of the Mexican Government, the opinions expressed are only his personal views for which the Mexican Government can in no way be held responsible. Notwithstanding that the appointment covers all phases of the so-called petroleum question, as the one question of immediate importance was that relating to taxation, it was decided to devote all the time to this phase of the work. The present report has been divided into two closely related parts, the first dealing with the production and marine transportation of Mcxican petroleum, and the second, with the Mexican taxation on petroleum and its products. The writer wishes to acknowledge the loyal cooperation rendered by Mr. M. C. Ehlen, who had charge of the statistical work, and by Miss S. Stern and Messrs. E. P. Heiles and J. E. Morrissey. The aim throughout the work has been to pave the way for a thorough understanding between the Mexican Government and the oil operators and to present a true and clear statement of facts relating to the questions at issue. Mexican Oil Fields Development The salient features in the development of the Mexican oil fields may be summarized as follows: 1901. First commercially productive well in Ebano field. 1902. Tehuantepee field came in; Diaz Government granted concession to Pearson & Son on practically all Federal lands along the Gulf of Mexico. 1907. First producing well in the Furbero field. 1908. Dos Bocas well caught fire, advertising tremendous productivity of Southern oil fields of Mexico.

Jan 1, 1921