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By C. J. A. Mcewan, C. M. Rice

The Rosita Hills contain rich, vein- and breccia pipe-hosted precious metal deposits. Volcanic activity occurred in two cycles - an early, mainly andesitic cone-building phase that terminated in the formation of a caldera and breccia pipes and a later phase characterised by trachytic lavas and dykes, rhyolite domes and lamprophyre dykes. Alteration consists of weak propylitic and argillic and, locally, intense advanced argillic, K-feldspar sericitic and silicic types. Marked trace-element depletions (Rb, Sr, Zn, Mn) are associated with K-feldspar-sericitic alteration and with advanced argillic alterations, whereas enrichments (Pb, Ag) are associated with K-feldspar-sericitic alteration. Gold distribution is highly localised and is controlled by breccia pipes and a caldera ring fault; it is not related to district scale alteration. In general, the geochemical and alteration patterns are complex, but they are clearly influenced by linear structures, the caldera ring fault and breccia pipes. Pipe-hosted Au-Ag and vein-hosted Ag mineralisation are associated, respectively, with early andesitic and late, post-caldera rhyolitic activity. The pipe-hosted and, especially, the vein-hosted mineralisation show affinities with adularia-sericite-type epithermal deposits

Jan 1, 1991

By Hamid Butt

Information Technology ??Advanced Information Technology is dramatically changing information flow within organizations. This enables employees to have information at their fingertips to make informed and prompt decisions. ??Real-time information allows timely analysis, which dramatically reduces cycle times, making organizations faster and more flexible. Business Challenges ??Continual growth of mining and Mine mobile fleet.??Increasing maintenance costs. ??Difficult to identify and troubleshoot equipment problems while equipment is operating. ??New equipment is increasing in complexity and cost. Therefore, each failure results in a greater impact to production and cost. ??Troubleshooting practice is reactive. ??Protect and optimize the use of mining assets to realize maximum business value. ??Maintenance and Operating information is not easily accessible ?no near real-time system that provides complete information.

May 1, 2006

By W. R. Reed

The National Institute for Occupational Safety and Health (NIOSH) uses light-scattering dust monitors (nephelometers) in its research to develop dust controls to reduce respirable silica dust overexposures in miners. Recently, the model 1500-pDR, an active nephelometer, was introduced by Thermo Scientific. Testing was completed to ensure compatibility with the metal/nonmetal mine dust personal sampling unit (M/NMDPSU). Results of testing demonstrated that gravimetric concentrations measured from the 1500-pDR are comparable to the gravimetric concentrations measured using the M/NMDPSU, without need for correction, under commonly observed dust loading conditions.

Jan 1, 2012

By D. Tsweleng

In the Evraz Highveld production process, iron ore is prereduced in rotary kilns prior to charging into submerged arc furnaces (SAFs). Owing to the highly aggressive slags that are formed within the combustion zones of these kilns, chrome-oxide-containing lowcement castables have been used for some years in the kiln lining. Due to concerns around the potentially harmful effects should Cr(V1) be present in the spent linings, Highveld and its suppliers of kiln castables devoted time to developing alternative chrome-free lining materials. Such materials needed to be cost-effective and ensure good performance and improved kiln availability. This paper discusses all the parameters surrounding this development. Keywords Low-cement castable, chrome-oxide free, chrome (VI), titaniferous magnetite ore, rotary kiln, submerged arc furnace, open slag bath furnace, Evraz Highveld Steel & Vanadium Limited.

Aug 1, 2013

"Bay d'Espoir is in the approximate center of the south coast of Newfoundland. The geology of the area can most conveniently be considered in terms of three units: (1) an Ordovician or older polydeformed terrain termed the Little Passage Gneisses; (2) a Lower-Middle Ordovician volcano-sedimentary sequence assigned to the Baie d'Espoir Group; and (3) granitoid intrusive rocks of mid-Paleozoic age. Mineralizing events accompanied the formation of the latter two units.The Baie d'Espoir Group comprises a dominantly sedimentary sequence of pre-Middle Ordovician shelf and distal turbidite sediments deposited on the eastern margin of Iapetus. A significant volcanic component is, however, present in the Isle Galet Formation, consisting of up to 30% felsic volcanic rocks interbedded with sedimentary and epiclastic rocks. The Isle Galet Formation hosts several disseminated to thinly bedded Pb-Zn-Ag occurrences associated with altered felsic tuff and graphitic shale. They occasionally grade laterally into pyrite iron formation and appear to have been deposited in a very distal volcanic environment. The Isle Galet Formation is a time equivalent of the mineralized pre-Caradocian island-arc sequences of central Newfoundland, but differs from them both in style of volcanism and in the nature of the associated mineral deposits. It is, however, comparable in many respects to mineralized volcanic sequences in the La Poile Bay area of southwestern Newfoundland.Mineralization associated with granitoid rocks in Bay d'Espoir is best developed around the southeast margin of the North Bay Granite, where two-mica leucogranite forms a marginal phase. Numerous minor base metal showings occupy quartz, quartz-carbonate and barite veins in the adjacent sedimentary rocks. Collectively, the showings exhibit a well-developed, zonal pattern around the granite margin; molybdenite (±py, cpy) predominates near the contact, giving way outward to galena (±sph, py, asp, cpy) and eventually to stibnite (±asp, py) at the periphery. Mineralization associated with granites in similar settings elsewhere in southern Newfoundland includes tungsten in the Grey River and Granite Lake areas and molybdenite in the Rencontre Lake area."

Jan 1, 1982

By Ari Glazer

"Every year the tunneling business is expanding and collaboration with the International Society of City and Regional Planners (ISOCARP) for the future design of cities and urban communities is in the making. During the last half of this century, billions of people migrated to cities, and it is estimated that by 2030 almost five billion people worldwide will reside in urban communities. Hence, “Underground development will be an important tool in reshaping our urban areas to meet the challenges of the future without destroying their heritage or worsening their surface environment” (Esaki, 2005). In 2013, the Organization for Economic Co-operation and Development (OECD) estimated life expectancy to be around 80 years, meaning that in less than a decade we will need to bury billions of people in cities and urban communities, while trying to retain the deceased’s beliefs and customs. Religion plays a major role in our lives, and many people worldwide still decline to cremate their body after their death; therefore, cemeteries are essential for city inhabitants. Rites and traditions usually call for burials to be near the place of residence, which allows the remaining family members and friends to visit the grave frequently, at least in the first years. This is a challenge that urban designers and architects must confront while trying to solve the problems of future urbanization. In recent years, population growth, the rising cost of land and the extensive preservation of green areas have made cemeteries a burden and a nuisance, particularly for large cities and communities. Many graveyards that were once on the city's outskirts have become lifeless islands in populated areas (Fig. 1), rarely visited by the second and later generations. Cities worldwide face the challenge of allocating less land to maintain current burial practices. In response, some cities have begun to bury their dead at a great distance from the community; others have started to stacked burials, one on top of the other, while still others are constructing buildings and even skyscrapers for the practice of burial (Fig. 2)."

Jan 1, 2016

By G. L. Oldright

The data presented in this paper were collected at the smelter of the Consolidated Mining & Smelting Co. of Canada, Ltd., Trail (Tadanac), British Columbia. Many thanks are due to S. G. Blaylock, vice president and general manager, James Buchanan, smelter superintendent, and George Murray, assistant smelter superintendent, for their broad general policy in permitting these data to be taken and published. life are also grateful for the help given by the staff members stated in Paper XI, Report of Investigations Acknowledgment is given several excerpts from experiments by F. E. Lee, head of the research staff. INTRODUCTION The past reputation of zinc as an ingredient in lead blast furnace slags has been bad. Zinc is thought of as a cause of accretions in the shaft of the blast furnace, of hot tops, of the formation of "zinc mush" in the crucible and forehearth, of lead-rich slags, of viscous slags, and. of low capacity in smelting.

Jan 1, 1934

The selection of the best comminution circuit for the preparation of concentration feed is a compromise based on economics, energy efficiency, labour costs, steel consumption, availability and other factors specific to each case. It is postulated that the selection must be a choice of one of the eight basic comminution circuits which can be divided into two basic groups, (1) autogenous or semi-autogenous primary mills with or without a secondary grinding stage and (2) fine crushing usually in cone crushers followed by a rod mill-ball mill circuit or a single stage ball mill circuit. The accuracy of selection may be improved by pilot plant and laboratory tests which are described in this paper. For (1) above, testing includes media competency tests with standard impact crushing, grindability and abrasion tests followed by pilot plant tests. For (2) above, bench scale crushability, grindability and abrasion testing is available. It is suggested that, through these tests, it should be possible to eliminate all but one in each group of basic comminution circuits. Then engineering and economic studies should lead to the best comminution circuit for the specific requirement.

Jan 1, 1984

By James W. Myers

The Bureau of Mines studied factors affecting ignition of coal mine refuse and on methods for control of burning. Laboratory experiments showed that air permeates more readily through segregated than through nonsegregated refuse and that air permeability is greater through coarse than through fine particle refuse. Minus 3-1/4-inch refuse ignites spontaneously more readily than minus 1/4-inch refuse. The burning of a 1,000-pound conical coal pile was con-trolled by capping with an 18-inch-thick layer of minus 1/4-inch refuse containing 37 percent combustible. In field trials, the burning of refuse at operating mines was controlled by capping with a layer of fine refuse. Water, applied as a spray or by injection, quenched surface flames and cooled the burning waste. Inspection of refuse piles at operating mines showed that the spontaneous ignition tendency is affected by the exposed surface relative to the total volume and the segregation of particles during dumping.

Jan 1, 1966

By Tapio Leskinen

"In the 1960’s, when large flotation machines appeared on the market, this was a part of a world-wide trend towards the use of ever larger machine units.One factor that has played a decisive part in this development is the increased of the amounts of ore that have to be handled as the exploitation of successively poorer ores becomes necessary. The advancing application of instrumentation and automation has worked in the same direction.In 1970, a working group was set up within Outokumpu Oy, for the purpose of flotation machine development. The principal task of this group was to be the design and development of- a new type of rotor of increased efficiency, especially for the dispersion of large amounts of air- a mechanical-pneumatic flotation machine of substantially larger size that existing plant.This development project required an extensive program of theoretical investigation and experimental studies at several concentration plants of the company.The commonest flotation machine presently used in the concentration plants of Outokumpu Oy is the VK-3. It is of the mechanical-pneumatic type, and the volume of its cell tanks is 2.5 m3 per shaft. This machine was developed within the company, and its first development phase i s represented by the OKKO 3, built for the Kotalahti concentrator in 1959. It was, in its time, comparable in volume to the largest machines that were then in use anywhere in the world."

Jan 1, 1976

By D. E. Sherwood

Recent developments in high torque hydraulic rotary rigs has lead to the construction of secant bored pile walls by rotary drilling methods in circumstances where earlier methods were difficult and in some cases impossible. The evolution of secant bored pile wall construction is described including classical, rotary drilled and continuous flight auger construction methods. The paper then details the restraints which have been created in recent inner city redevelopment, many of which were not relevant in the early days of the technique. Typical examples of walls are presented to show the adapatability and advantages of the secant bored pile wall method. A number of in-situ retaining wall construction techniques are then compared in detail with regard to relative cost, technical quality and practicality.

Jan 1, 1989

By R. N. Edmondson, L. Mair, M. Tenenbaum

It is the policy of The Metallurgical Society to provide, in the TRANSACTIONS OF THE METALLURGICAL SOCIETY OF AIME, a prompt and accurate medium for publication of reports of significant new research in both the scientific and engineering aspects of metallurgy. Papers submitted to the Society are judged by competent reviewers according to established criteria for technical merit, accuracy, originality, and presentation. STAFF: Editor, Dr. Gerhord Derge; Editorial Assistant, M. A. Redmyrski; Staff Coordinator, James J. Burke. THE METALLURGICAL SOCIETY: W. R. Hibbard, Jr., President; J. C. Kinnear, Jr., Past-President; John Chipmon, Vice President; T. D. Jones, Treosurer; R. W. Shearman, Secretary. PUBLICATIONS COMMITTEE OF THE METALLURGICAL SOCIETY: A. w. Thornton, Chairman; Dennis Carney, John Chipman, J. C. Fulton I. H. Hollomon H. H. Kellogg, A. E. Lee, R. Maddin, J. D. Sullivan, and D. Swan. Review and selection of manuscripts is under the supenision of the following Publications Committees: Extractive Metallurgy Division: T. 0. King Chairman; S. J. Dickenson, R. P. Hermsdorf R. Schuhmann. Jr.. and P. T. Stroup. Institute of Metals Division: Robert Maddin, Chairman F. Lincoln Vogel Jr., Vice-chairman, W. A. Baikofen, R. W. Boliuffi J. H. Bechtold M. B. Beyer. R S. Busk, C. G. Gaetzel, Paul Gordon C. D. Groham, Jr., Robert F. Hehe-mann,' R. I. Joffee, F. c. Joumot Jr lrving R. Kramer A. J. Lena Harold Morglin, C. J. McHargue, Russell A: Meussner, J. B. Newkirk H. W. Paxton, G. E. Pellissier, I. S, Servi, Alon U. Seybolt, A. J. Shaler, and Jack Washburn. Iron and Steel Division: J. C. Fulton, Chairman; T. B King, F. C. Langenberg, W. 0.. Philbrook, and T. 0. Winkler. Published bimonthly by the American Institute of Mining Metallurgical and Petroleum Engineers Inc., 29 West 39th Street, New York 18, N. Y. Telephon: pEnnsvlvanio 6-9220. Subscription 522 Per year for non-AIME members in United States and North South and Central America; $25 foreign;, $5 for AIME members. Single copies, 54.00, single copies foreign, $5.00. The AIME is not responsible for any statement made or opinion expressed In its publications . . . Copyright 1958 by the American lnstltute of Mining Metallurgical and Petroleum Engineers Inc. . . . Registered cable address AIME New York , . . lndexed in Engineering Index Industrial Arts Index and Chemical Abstrats . . . Application for second class mail privileges ii pending at New York, N. Y. Volume 212, Number 4.

Jan 1, 1959

Standards And Laboratory Monitoring In Gold Assay Key Components Of Best Practice

Jan 1, 2005

By M. J. Farrell

Mining is a significant emitter of greenhouse gases and is the focus of increasing attention from green groups and regulators. Miners need to know their own carbon emissions and how they compare with the rest of the industry. Miners and mining companies need to know where they fit in the emissions curve. Who is in the bottom quartile? This article updates data from minecost.com which detail the specific carbon dioxide emissions for over 200 mines producing 90% or more of western world copper, zinc, lead and nickel in 2009. This data shows the potential impact on mine economics of proposed carbon taxation regimes and emissions trading schemes proposed at COP 15 in Copenhagen during December.

Jan 1, 2010

By D. R. Wilburn

This summary of international mineral exploration activities for the year 2007 draws upon available information from industry, literature and U.S. Geological Survey (USGS) specialists. The summary provides data on exploration budgets by region and mineral commodity, identifies significant mineral discoveries and areas of mineral exploration, discusses government programs affecting the mineral exploration industry and presents analysis of the mineral industry based upon these data. Two types of information are reported and analyzed in this annual review of international exploration for the year 2007: 1) budgetary statistics expressed in U.S. nominal dollars provided by Metals Economics Group (MEG) of Halifax, Nova Scotia, and 2) information on regional and site-specific exploration activities that took place in 2007 and compiled by the USGS.

Jan 1, 2008

By Michael B. Gilbert

The Woodbury L-73 Tunnel involved the design and construction of a 96-inch tunnel driven through 8,080 lf of very difficult ground conditions. Anticipated ground and groundwater conditions consisted of potentially flowing silty sand with cobbles and boulders, mixed face of sand and sandstone and full face of the St. Peter Sandstone. Actual conditions were similar, although the quantities did change from bid quantities. This paper presents the approach used for development of the GBR regarding risk management. The means of arriving at a fair compensation for variances from the baseline values to address the actual encountered tunneling behavior of the soil, boulder count and its effect on production rates are presented.

Jan 1, 2008

The mineralisation consists principally of layered pyrite, phalerite and galena, situated conformably within a sequence of tuffaceous, bituminous shales and dolomitic sediments that include slump breccias. The sediments show little evidence of post sedimentary reconstitution. A volcanic-exhalative-sedimentary origin is postulated for the mineralisation. Attention is drawn to the similarity between the McArthur deposit and the lead-zinc-silver orebodies at Mount Isa. The primitive nature of the sulphides is reflected by their adverse metallurgical behaviour, and it seems that the best prospect for milling and flotation benefication may lie in the production of separate zinc and bulk concentrates

Jan 1, 1968

By N. A. Eilertsen

This paper presents the results of intermittent study begun in 1956 by the Federal Bureau of Mines of yieldable steel arches and yieldable steel ring sets installed for support of development openings in metal mines. Observations were made of this type of support in several iron mines in the northeast and north-central states. The sets, both arches and rings fabricated in the United States, are made from a hot-rolled, cold bent, structural U-shaped steel section in two weights, 15 pounds and 21 pounds per foot. The lighter section is generally used, It is 4.41 square inches in cross section area, and the calculation is that a 6-foot length of this structural shape installed as a supporting column, will safely carry the same load as a Douglas fir post of the same length but of 22 times the cross-sectional area of the steel.

Jan 1, 1962

By J. J. Brummer

The possibility of diamonds occurring in Canada was first raised by W. H. Hobbs in 1899, who concluded: "that the apex of the fan of diamond distribution probably lies somewhere in the strip of the territory bordering James Bay on the east." This was based on the occurrence of diamonds in surficial sediments at various locations south of the Great Lakes. There are two recorded discoveries of drift diamonds in Ontario: (a) the Peterborough Diamond, 33 carats in size, poorly documented and found sometime before 1920;and (b) the Jarvi Diamond, 0.255 carat, found during 1971 in Sheraton Township near Timmins . Both discoveries were in surficial sediments and their source(s) have not been located. During 1960, Selco Exploration Company Ltd. started a heavy-mineral sample program of river gravels in the James Bay Lowlands of Ontario. This was continued by Canadian Rock Company Ltd. (1962-1963) and the Ontario Division of Mines (1973). The surveys discovered the presence of kimberlite minerals in gravel samples from streams draining the Moose River Basin. A total of 53 pyrope grains, four magnesian ilmenites and one grain of chrome diopside were identified from 32 sample locations. A study of the distribution of these minerals suggested the kimberlite source rocks to be located along the north margin or within the Kapuskasing gravity "high" in the area immediately south of James Bay. The Jarvi Diamond, found on an esker east of Timmins, could well have originated from this area. During 1965, an esker was sampled by the Geological Survey of Canada, and the results attracted attention to the area south of Lake Abitibi. At 9 out of 34 sites sampled along the Munro esker, Lee recorded the presence of pyrope garnets and very minor chrome diopside.

Jan 1, 1978

By Bengt H. Fellenius

Session 2, Deep Foundation without Soil Excavation, has attracted no fewer than 22 papers dealing with subjects from soil improvement by grouting, injection, and deep mixing techniques through vibroflotation and special piles, including aspects pertaining to conventional driven and bored piles. In the short time available, it is not possible to both do justice to the papers and provide a critical review of the state-of-the-art. Instead, to meet the objective of making the next half hour worthwhile to the audience, I have chosen to comment on a few special points brought forward in the papers and thereafter to discuss more in detail a couple of aspects I have deemed to be of general interest. Four papers deal with jet-grouting, injection, and deep mixing techniques: DOMSKI, J. J. Reinforcement of subsoil under the foundations of historical buildings in Cracow using deep injection technique. RESTELLI, A. B, BERTERO, M., and LODIGIANI, E. Deep mixing technology to improve the bearing capacity of a very soft clayey soil under an earth embankment.

Jan 1, 1994