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Sphalerites from Devonian cassiterite-sulphide deposits and Pb-Zn-Ag fissure veins have similar ranges of Cd contents, but the average Cd and Fe contents could indicate a small initial difference in availability of Cd between the Zeehan-Renison Bell district and the Mt. Bischoff-Waratah district. Sphalerites from banded Pb-Zn deposits (Rosebery and Hercules) are characterized by low Cd content which is a world-wide feature of such deposits in exIrusive rocks, and may indicaIe a genetic relationship between ore deposition and vulcanism.

Jan 1, 1968

By T. Owen

Not since 1917 has a foreign company developed a standalone, grass roots gold mine in Russia. With. Russia's political changes of the late 1980s, development of mineral prospects once again beckons foreign investors. In 1990, Cyprus Amax began aggressively searching for such an opportunity. Early in 1997, production will commence at the Kubaka gold project located in the Russian Far East, near the Arctic Circle. The Kubaka project is a 1,750-tonne per day open-pit operation that will produce more than 300,000 ounces of gold per year. This paper discusses the challenges of locating such a prospect, doing business in Russia, developing supply lines, identifying work force capabilities, gaining government approvals, securing financing, arranging for gold sales and ultimately building a facility in this arctic region.

Jan 1, 1997

By Edward Thomas

Yucca Mountain Overview The U.S. Department of Energy?s Yucca Mountain Project is a geologic repository project designed to receive, handle, package, transport, and emplace spent nuclear fuel and high level radioactive waste. The planned repository would be located in Yucca Mountain on the western edge of the Nevada Test Site, about 90 miles northwest of Las Vegas, Nevada, and would include both surface and subsurface areas. Yucca Mountain rock formations consist of successive layers of volcanic rocks (called tuffs) approximately 14 to 11.5 million years old, formed by eruptions of volcanic calderas to the north. With the volcanic rock the potential for methane emission is not an issue and the subsurface repository is a non-gassy (methane) classification. This paper will provide a summary of the development ventilation system design that provides fresh air for subsurface construction activities, and the emplacement ventilation system design that removes heat generated by the waste packages. The subsurface layout, illustrated in Figure 1, contains 108 emplacement drifts, one Performance Confirmation(PC) observation drift, nine intake/exhaust shafts, and three access ramps. The existing Yucca Mountain facilities, shown in bold lines in Figure 1, include a 7.8 km long, 7.62 m (25 ft) diameter U shaped tunnel that is formed by the North and South Ramps at both ends of the Exploratory Studies Facility (ESF) drift and a 1.5 km long, 5.0 m (16.4 ft) diameter Enhanced Characterization of the Repository Block drift (ECRB) that were constructed from 1994 through 1998. These drifts were used for site characterization activities and have been incorporated into the subsurface repository configuration. The unexcavated perimeter access main and exhaust main drifts are typically 7.62 m (25 ft) diameter TBM excavations and the emplacement drifts are 5.5 m (18 ft) diameter TBM excavations. The turnouts leading into the emplacement drifts are to be excavated by either mechanical, or drill and blast methods and serve as the launch chambers for the emplacement drift TBM excavations.

By Richard Wilson

In the early 1970s, it became a concern that exposure to the mineral fibers associated taconite ore processed in Silver Bay, Minnesota would cause asbestos-related disease including gastrointestinal cancer. At that time data gaps existed which have now been significantly reduced by further research. To further our understanding of the types of airborne fibers in Silver Bay we undertook a geological survey of their source the Peter Mitchell Pit, and found that there are no primary asbestos minerals at a detectable level. However we identified two non-asbestos types of fibrous minerals in very limited geological locales. Air sampling useful for risk assessment was done to determine the type, concentrations and size distribution of the population of airborne fibers around Silver Bay. Approximately 80% of the airborne fibers have elemental compositions consistent with cummingtonite-grunerite and the remaining 20% have elemental compositions in the tremolite-actinolite series. The mean airborne concentration of both fiber types is less than 0.00014 fibers per milliliter that is within the background level reported by the World Health Organization. We calculate the risk of asbestos-related mesothelioma and lung cancer using a variety of different pessimistic assumptions. (i) that all the non-asbestos fibers are as potent as asbestos fibers used in the EPA-IRIS listing for asbestos; with a calculated risk of asbestos-related cancer for environmental exposure at Silver Bay of 1 excess cancer in 28,500 lifetimes (or 35 excess cancers per 1,000,000 lifetimes) and secondly that taconite associated fibers are as potent as chrysotile the least potent form of asbestos. The calculated risk is less than 0.77 excess cancer case in 1,000,000 lifetimes. Finally, we briefly review the epidemiology studies of grunerite asbestos (amosite) focusing on the exposure conditions associated with increased risk of human mesothelioma. © 2008 Elsevier Inc. All rights reserved. Keywords: Risk; Fibers; Particles; Taconite; Asbestos; Exposures

Jan 1, 2007

When asked to lecture at Bendigo on the geological factors that determine the depths of ore deposits, I hesitated for a little before agreeing to lecture on the theory of deep ores in the city world famous as the pioneer of deep gold mining. If there be one place, wherein the conditions of deep-seated ore deposits should be sufficiently well understood, it is the city where the 180 mine made its bold plunge to previously neglected depths; and where the record of that famous mine has been broken by the skill of the managers, and the pluck of the proprietors, of the New Chum Railway and Lazarus mines.In the face of such practical triumphs, theoretical discussion may seem a waste of time, especially since it is often dedared that the existence of such deep-seated ores was denied by geological theory. This assertion is, however, startling since the oldest and best supported geoiogical theory of ore deposits, has taught for more than a century tliat ores must descend far below the regions of practical mining. This charge against Victorian geologists is generally based on opinions attributed to the late Sir Fredrick McCoy. It has been repeatedly affirmed that he declared that gold cannot occur pelow a depth of 300 feet. But so far I have not been able to discover that McCoy ever made any such assertion or ever held such a view.

Jan 1, 1902

By Joseph J. Wallace

1. From the standpoint of present production and recoverable reserves, there are two beds of major importance in Allegheny County -Pittsburgh and Upper Freeport -and one of lesser importance -Redstone. 2. Known measured and indicated reserves in all beds, based on a minimum thickness of 14 inches and 1,800 short tons per acre-foot of coal in place, are estimated at 832 million short tons as of January 1, 1953. Of this total, 768 million short tons is in beds 28 inches and more thick. Areas in some beds were omitted from the estimate because available data relative to the bed characteristics are too meager for making an estimate that conforms with the definitions of measured and indicated coal adopted for this study. Should future drilling or development prove reserves in these areas, such reserves should be added to the total estimated reserves.

Jan 1, 1953

By J. J. Dowd

1. The Pittsburgh bed is the most important bed in Brooke County and virtually the entire production of coal in the county comes from this bed. 2. Known measured and indicated reserves in all beds, based on a minimum thickness of 14 inches and 1,800 tons per acre-foot of coal in place, are estimated at 191 million short tons as of January 1, 1954. Of this total, 190 million short tons are in beds 28 inches and more thick. Areas in each bed were omitted from the estimate because available data relative to the bed characteristics are too meager to make an estimate that conforms with the definitions of measured and indicated coal adopted for this study. Should future drilling or development prove reserves in these areas, such reserves should be added to the total estimated reserves.

Jan 1, 1955

By Paul M. Tyler

One of the best present-day yardsticks of the material welfare of a nation is its consumption of minerals, The United States, with only 7 percent of the world population, consumes 45 percent of the world wealth, pays the highest real wages, has the shortest working hours, and numbers the largest percentages of home owners among its population, and at the same time its per-capita consumption of minerals is far greater than that of any other nation. In 1937, British India, with roughly twice the population of the United States, used less than 2 percent as much lead, 4 percent as muck zinc, and 13 percent as much copper; even in Europe, which has three times our population and where war preparations have greatly expanded the normal needs of peaceful industries, the aggregate consumption of metals and industrial minerals other than lignite is less than the total for the United States alone. The march of civilization passed from the Stone Age to the Bronze Age before the dawn of history. It may be questioned whether man or monkey first threw stones at an enemy, but only man could have fashioned rough stones into weapons. Eoliths rudely shaped by apelike men are believed by archaeologists to have antedated by hundreds of thousands of years the existence of our own human ancestors. The primitive people that followed the retreating Ice Cap northward in early quaternary period - at least a million years ago - were fairly adept in the shaping of flints and even used a little copper. The Bronze Age, so-called, superseded the Stone Age when, around 8,000 B. C., the news spread that chunk s of natural copper could be pounded into better weapons or cutting implements than ever could be made by chipping stones. The Bronze Age gave place to the Iron Age about 1,000 B, C., and though students of modern history may speak of the Coal Age, the Petroleum Age, and the Automobile Age, and so on, these ages have all been crowded into a brief century and a half. The truth is that we still are in the Iron Age, unless perhaps we choose to call it the Age of Many Metals.

Jan 1, 1940

By Antti J. Perala, Teemu J. Yli-Kovero

"Efficient use of land is constantly requiring more underground construction. Minimized execution time and disturbance to surroundings and nearby structures are essential benefits for all construction techniques. To meet the demands of a modern construction project, suppliers have to be able to provide high-quality and tailor-made products just on time. RD pile wall is a retaining wall based on drilled steel pipe piles which are connected to each other with special interlocking profiles. RD pile wall is a solution which enables penetration of overburden soil, dense fill layers including stones and boulders, and embedding into the bedrock in one single operation. Several test installations and laboratory tests have been made to develop the system and to test and improve the water tightness of the wall. Beside these tests, RD pile wall has also proven its reliability in almost 70 projects. Largest project so far has been Pasila Tripla project in Helsinki, Finland. A permanent retaining wall with surface area of 18,000 m2 (193,750 ft2), excavation depth of 21 m (68 ft) and over 17 m (56 ft) of water pressure was made with 711 mm (28”) and 406.4 mm (16”) pile sizes. Piles were delivered to site in one piece with lengths up to 33.5 m (110 ft).INTRODUCTIONExcavations in cramped city centers and in between of existing buildings and other structures are facing more and more challenges. Installation of sheet pile walls is often problematic or even impossible due to obstacles in ground from old structures and due to demand to extend the excavations to even deeper and harder soil layers. Also installations of secant pile walls are facing difficulties due to cramped construction sites and constantly tightening execution times.On the other hand, an efficient and reliable piling technique suitable for the demanding soil conditions described above, percussion drilling, has been developed since the 1960’s, and especially from the mid- 1990’s, when the concentric drilling method with the ring bit and pilot was introduced. A new retaining wall application, the RD pile wall, was developed by combining that drilling method with the widely used retaining wall solution based on steel pipe piles and welded interlocks (a pipe pile wall normally installed with vibratory or impact hammers).PRINCIPLE AND MAIN BENEFITS OF THE METHODRD pile walls can be used in all soil conditions. Most beneficial the system is in extremely demanding soil conditions where the installation of traditional retaining walls is challenging or even impossible. The RD pile wall is a combination of drilled steel pipe piles and interlocking sections as shown in Fig. 1.Individual RD piles are connected to each other with interlocks welded to the piles on the automated welding line at the workshop. The matching dimensions of the drilling system and interlocking sections allow the installation of RD piles through stones and boulders and even into the bedrock, if necessary, in a single operation. Installation is done by a down-the-hole (DTH) hammer using the centric drilling system and oversized ring bits or a drilling system consisting of a pilot bit and reamer wings shown in Fig. 2."

Jan 1, 2017

By Shosei Ph. D Serata

The Stress Control Method of mine design provides enhanced engineering control over the behavior of underground structures in comparison to conventional mine design methods. The same Method can be applied to achieve design control of surface subsidence. The basic mechanism relating undergroued deformation and surface subsidence is disclosed by mine simulations, using the REM (Rheological Element Method) computer code, whose predictions have been validated by field measurements. The key components of the underlying mechanism of surface subsidence have been shown to be the stress envelopes formed in the process of underground excavation. It has also been demonstrated that significant control of surface subsidence can be achieved by designing the geometry and timing of underground excavation to regulate the formation of stress envelopes. A field example is given in this paper to illustrate this application of the Stress Control Method.

Jan 1, 1986

Research 82 highlights significant studies conducted during the past fiscal year at Bureau facilities and offices. Readers who want more information about the projects and studies summarized here can contact the researchers whose names and locations appear with each summary. General information on Bureau of Mines programs is available from the Office of Technical Information, 2401 E Street, NW., Washington, D.C. 20241. A listing of principal officials, a location map of field facilities, and a selected bibliography of publications and patents issued on Bureau developments during the past 3 years are provided.

Jan 1, 1982

By Angus D. Campbell

Introduction In the Twentieth Annual Report of the Mcintyre Porcupine Mines, Limited, for the year ending March 31st, 1932, the General Manager, Mr. R. J. Ennis, said: "During the period under review, the plans outlined in last year's report have been completed, and all operations have been centralized in the new plant adjacent to No. 11 shaft. The new mill went into operation on May 27th and attained its rated capacity of 2,000 tons per day on November 15th. The new shops, warehouse, change-house, and general offices were occupied on December 1st, consummating the change from the old to the new plant ... "Silicosis is now definitely recognized as an industrial disease, and progresses rapidly when associated with tuberculosis. In an effort to combat its prevalence and progress, the new change-house was designed to build up the men's resistance to this and other forms of disease. It provides for a complete change from underground to street clothing, with a shower bath and solarium treatment in the interval. 'Unfortunately, in almost every goldmine, a very small percentage of the work-men are not adverse to taking some of the high-grade ore for their own purpose. This, in turn, tends to cast suspicion upon the honourable as well as the dishonorable employees. The new change-house routine discourages this practice and eliminates unjust suspicion, to the satisfaction of all concerned with the Company's operations".

Jan 1, 1933

A brief review is given of the history of the Colliery to date together with the reasons for the development of an additional seam.Investigations into the quality of the coal ami its suitability for the production of metallurgical coke and determination of the economic mining limits and coal reserves are discussed. The commencement of mining operations and the inter-seamarrangements necessary for the disposal of coal won are described with the stages in the opening out of the seam itself and the reasons for the installation of a 48-in. trunk conveyor belt. Choke and manning of face equipment are considered and also the work of secondary development and pillar extraction.It is concluded that with modern face equipment and conveyor belt lines, concentrated mining followed by immediate extraction of pillars is practicable and is giving excellent results at Burwood Colliery.INTRODUCTIONBurwood Colliery, the total holding of which now comprises some 3,140 acres of land and 1,450 acres of sea leases, has mined the Borehole Seam since 1883. The early work took place from Nos. 1 and 2 shafts at Glenrock Lagoon and later on at Nos. 3 and 4 shafts at Whitebridge to which the centre of operations shifted in 1893, shaft sinking at this latter area having commenced in 1888.As all the early operations were confined to the Borehole Seam, reserves of coal on this horizon had been considerably reduced by the mid 1930's, so a cross measure drift was driven to the Victoria Tunnel Seam which is about 300 ft. above the Borehole Seam, and fully mechanized coal winning commenced from the second seam in 1938. Subsequently this cross measure drift was extended to the Borehole Seam and complete mechanization of the south-west sections of this seam achieved by 1945.Four track mounted mechanical units were put into operation in the latter area and these worked in a southerly and...

Jan 1, 1958

By F. E. Brantley

Research was undertaken by the Bureau of Mines to assess the technical feasibility of smelting cement-copper precipitate in an electric furnace to produce commercial-grade copper. The blister-grade copper produced in smelting was refined by gaseous oxidation and reduction methods to rive a product equal in quality to fire-refined copper. The cement copper used in the study was typical of the material produced in commercial operations. The sample product was received in a partially oxidized state and analyzed 77.5 percent Cu, 3.4 percent Fe, 0.8 percent Pb, 0.05 percent Ni, 0.6 percent Sn, and 0.9 percent S. Smelting tests were made on the precipitate using laboratory-size induction and electric-arc furnaces. Three types of furnace linings were tested during, the investigation: Carbon, including graphite; clay-graphite; and silicon carbide. Although all proved satisfactory, either carbon or graphite was preferred because of their superior refractory properties and low permeability to molten copper. Copper recoveries in the induction and arc smelting tests averaged 92 percent in commercial-grade metal assaying 99.8 percent copper. Refining the molten copper by oxidation and gaseous reduction or by chlorine lancing increased the purity to plus 99.9 percent.

Jan 1, 1961

By C. Velásquez, W. Bergholz, C. Spence, P. Lind

NuevaUnión SpA (NuevaUnión) is a development project located in the Huasco province of the Atacama region of Chile. It is held in a joint venture company owned 50:50 by Teck Resources Limited (Teck) and Newmont Goldcorp. It includes the Cu-Mo Relincho deposit and the Cu-Au La Fortuna deposit, with plans to utilise a single concentrator to be built at the Relincho site. The Relincho site is at an altitude of 2,000 masl and is 40 km from the La Fortuna site which is at an altitude of 4,100 masl. The project is currently completing a Feasibility Study and is reviewing equipment selection and flowsheet options. This paper is based on the current thinking, and design decisions will be finalized at the completion of the Feasibility Study. NuevaUnión is currently planning for phased operation, processing Relincho ore at 104 ktpd followed by processing ore from La Fortuna at 116 ktpd. Plans for the third phase include doubling the main processing lines and returning to Relincho ore at a processing rate of 208 ktpd. The NuevaUnión concentrator will incorporate comminution and flotation circuits that are being designed to maximize the overall economic value of the combined ore deposits. Major ore characteristics differ between the two ore bodies, such as ore competency, grindability, liberation grind size, pulp rheology, tailings properties, minerals and metals of value, as well as gangue mineralogy. Mineral processing choices have been made to optimise value from each deposit and the combined project. INTRODUCTION Between 2010 and 2013, two significant mining projects were being developed in Chile: Goldcorp’s El Morro project had recently finalized a Feasibility Study and, in 2011, had received its environmental approval for construction; and Teck Resources Limited’s (Teck) Relincho project was finalizing a Feasibility Study and preparing its Environmental Impact Study. Both projects were: Geographically close, at only 40 km apart. Considering similar infrastructure. Each was planning to have its own concentrator, tailings management facility, high voltage power line, port, concentrate transport system, seawater desalination plant and pumping system to mine site.

Jan 1, 2019

By Walter Murphy

For a number of years the Bureau of Mines has been studying the properties of crude petroleums produced in the United States and the Western Hemisphere. A number of reports have been published giving the analyses of crudes from the different field and regions as made by the Bureau of Mines Hempel method of analysis.4/ Several of these reports include analyses off crude oils from the Rocky Mountain region.5/ The search for new fields and new producing horizons in old fields in the Rocky Mountain region has been quite intensive during the last few years, and a number of discoveries have been made.

Jan 1, 1937

By E. R. Bauer

In response to the mandates in the MINER Act of 2006, NIOSH conducted refuge alternatives research that included characterizing the utility, practicality and survivability of refuge chambers and outby safe havens. NIOSH also prepared and delivered a report to Congress in late December 2007 that summarized the findings of the research, included recommendations concerning the design and performance specifications for refuge alternatives, and focused on specific information that could inform the regulatory process on refuge alternatives. This document highlights NIOSH's research and recommendations concerning refuge alternatives, survivability evaluations of refuge chambers, and presents a brief review of the current deployment of refuge chambers in underground coal mines in the U.S. The research has lead to the conclusion that refuge alternatives have the potential for saving the lives of mine workers if they are part of a comprehensive escape and rescue plan, and if appropriate training is provided. DISCLAIMER: ?The findings and conclusions in this report have not been formally disseminated by the National Institute for Occupational Safety and Health and should not be construed to represent any agency determination or policy.?

Jan 1, 2009

By D Mnller, J L. Mauk

The Oblaga Cu-Au skarn deposit and porphyry prospect is located in the south-eastern edge of the Gobi Desert in western Inner Mongolia. The deposit occurs within metamorphosed middle Paleozoic volcanic, plutonic and sedimentary rocks.   Ivanhoe geologists recognise eight main rock types in the area. Calcareous sediments include conglomerate, interlayered siltstone-sandstone, and limestone. Covering the calcareous sediments is a slab of thrusted biotite granite, and above it is rhyodacitic lithic tuff which, in places, is overlain by alluvial sediments. Various plutonic rocks and related intrusion breccias have intruded these units. Monzodiorite, quartz-monzonite and monzonite tend to form thin, high-angle intrusions and the youngest andesitic intrusions are generally wider and subhorizontal.   The Oblaga Cu-Au skarn, which occurs in the calcareous sediments, shows typical prograde and retrograde mineralogy. Petrographic studies show that prograde skarn minerals have been overprinted by retrograde skarn minerals, and original host rock minerals have been texturally obliterated and completely replaced. The mineralogy of the Oblaga skarn deposit is very similar to other Cu-Au skarn deposits worldwide.   Sericitic and minor chloritic alteration occurs throughout the study area and may relate to porphyry-style mineralisation. Generally, this alteration is not intense and most rocks have retained their original texture. Geochemical analyses suggest that K-metasomatism is not widespread at Oblaga. XRD analyses suggest an upward and outward transition from sericitic to chloritic alteration.   Comparisons between Oblaga and other porphyry Cu-Au deposits worldwide show that Oblaga has very similar characteristics to deposits that have undergone sericitic alteration. However, Oblaga is special because it also has relatively intense chloritic alteration, which is uncommon in other porphyry Cu deposits described in the literature.

Jan 1, 2005

By W. H. McAllister

The paper considers the geology and the coalfields that comprise the Scottish south area. It traces the history of known sources of spontaneous combustion and indicates the collieries concerned, with the position of the seams in the geological series where heatings have occurred. The methods of work over the years are described. It relates in detail the circumstances surrounding a fire at Bilston Glen Colliery in the Lothian Coalfield, and the heating at Killoch Colliery in the Ayrshire Coalfield, and the steps taken to deal with them. It also describes some of the difficulties in steep seam working. Methods adopted to prevent spontaneous combustion throughout the area are discussed, and some detail of the UNOR gas analyser is given. Finally, it comments on the present techniques in use in the area, particularly at Bilston Glen Colliery, to prevent spontaneous combustion.

May 23, 1905

By Harvey Parker

The International Tunnelling and Under-ground Space Association (ITA) is a nonprofit organization that represents all aspects of the tunneling and underground space industry worldwide. The United States has had a prominent role in ITA since its 1974 inception. ITA was formed as a result of a worldwide survey conducted in the early 1970s by the Organization for Economic Cooperation and Development (OECD). Bill Lucke was in charge of tunnels for the U.S. Federal Railroad Administration and was a member of the organizing committee that created ITA. He became a vice president of ITA. Jack Lemley served as President of ITA from 1983 to 1986. Dick Robbins was very active in ITA and served for many years both as a member of the Executive Council and as First Vice President. Harvey Parker has served as President of ITA for the last three years and will serve as Past President for the next three years. Moreover, there are many individuals and companies from the United States that have contributed significantly to the activities and the success of ITA. There have been several active Working Group Animateurs from the U.S. and there have been significant contributions from many individuals as well as companies from the U.S. Several engineers from the U.S. are currently serving ITA in a leadership role. The Underground Construction Association of SME (UCA of SME) is the official organization representing the U.S.. SME Executive. [ ] Director Dave Kanagy and UCA President Tom Peyton were instrumental in the U.S.?s role at ITA during the last few years. Peyton has been the official delegate to ITA. Henry Russell and Christian Ingerslev are both Animateurs of ITA working groups. This article will introduce ITA and its activities. A subsequent article will describe the ITA in more detail and will discuss the significant role the U.S. has played in the development and success of ITA.

Jan 1, 2007