Search Documents

By John Wightman

LOCATION OF PROPERTY THE property of Caribou Gold Mines, Limited, is situated in the north-eastern part of Halifax county, seven miles south of the Canadian National railway line at Upper Musquodoboit. Approach to the village is by a secondary road, improved recently by waste rock from the mine dump. A two-wire telephone line, seven miles long, built and owned by the present operators, provides communication to the nearest telephone exchange, Parker's Corner. HISTORY In 1870, the Caribou area was recognized as a proclaimed gold district. From then on, operations were intermittent, with periods of considerable activity by small companies until there were no fewer than seven mines in a district two miles long by three-quarters of a mile wide. These were the Holman, Truro, Caffrey, MacDonald or Elk, Lake, Dixon, and Hilchey properties, all of which have had separate stamp-mills, and have produced gold for varying periods. Depths of the workings range from 100 feet to 1,000 feet. Power was generated at each property by means of steam boilers. At the present time, the Consolidated Mining and Smelting Company of Canada, Limited, controls all the leased areas, approximately 800 acres, and is operating by means of one central vertical shaft. GEOLOGY The district in and about Caribou Mines has an elevation of approximately five hundred feet above sea level. The area is fairly well wooded, with rock outcrops here and there. These outcrops, along with information from test-pits and shafts, have been the basis for the very excellent geological map of the district prepared by E. R. Faribault some years ago. The rock structure, which is one of the best examples in Nova Scotia of an elliptical dome, has its anticlinal axis in a northeast-southwest direction, and flat plunges in the same directions.

Jan 1, 1938

By C. Groccia

As the search for new ore bodies drives mines to be developed at greater depths, the associated high stress environments present challenges for rock support design. Excavations in highly stressed brittle rock are often subject to large volume increases due to rock failure, a phenomenon known as rock mass bulking, which can result in significant wall convergence. Support systems need to be designed to minimize the amount of bulking and to accommodate large wall convergences. In order to design such a support system, empirical guidelines are often used to predict the amount of bulking. However, the empirical guidelines that are currently available are based on a limited number of case studies and consider few input parameters, which may result in an inaccurate bulking assessment. This paper describes methods of collecting quantitative field data at Creighton mine in Canada to better understand rock mass bulking and to further develop the empirical guidelines for bulking assessment for tunnels in highly stressed grounds. Measuring

Aug 1, 2013

By James E. Jones

The coal mining industry is being called upon to vastly increase production in the coming years. Many mining operations will have to prepare an environmental impact report of some kind and all will have to comply with various types of environ- mental regulations. Therefore there is a great need within the industry for access to environmental data, information, and literature. This paper discusses the informational resources available, the current lack of access to these resources, and the Environmental Data, Information and Literature (EDIL) Bank of the Kentucky Institute for Mining and Minerals Research. The bank's major emphasis concerns the environmental, social and economic aspects of producing clean solid, liquid, and gaseous fuels from coal. The data bank promotes information interchange between other related governmental and private projects and the energy development community.

Jan 1, 1976

By R. D. Berkenkotter

This report describes a weighted method for evaluating the mean and variance of assay data from samples of different length . The method , which produces unbiased estimates from which valid confidence limits can be computed , is appropriate for bedded deposits of variable bed thickness and for vein deposits of variable vein width . Assay data from the bedded Florida phosphate deposit is used to illustrate the procedure .

Jan 1, 1964

By J. Boltano

This paper discusses the study, design and implementation of the new gas handling system for the Caletones Smelter of Codelco-Chile. A discussion on design conditions for a future Sulphuric Acid Plant using Teniente Converter gases is also included. The old system which started to be modified in 1985 and relied on natural draft and used balloon flues, resulted in a limited gas handling capacity for operation under future process conditions. This system also caused excessive fugitive gases in the smelter working areas. The new system permits handling of process gases from the higher capacity Teniente Converters Installed in 1987-1989 improving the gas handling of the reverberatory furnaces and Peirce-Smith converters as well as the environmental conditions of the smelter. This system utilises improved converter gas hoods, evaporative cooling and electrostatic precipitators gas cleaning, and is based on natural draft.

Jan 1, 1992

By Oliver Bowles

The National Granite Commission at its annual meeting in Norfolk, Va., in January, 1930, passed a resolution requesting the Bureau of Mines to conduct an economic study of the granite industry. In compliance with this request a preliminary review has been made of trends, in, the production and uses of block granite. Some unfavorable conditions, were, thus brought to light and certain suggestions regarding a. more orderly and consistent growth in the industry are herein discussed. The results of the study axe, presented in this report for the earnest consideration of the industry and comments are invited, not only on this report but as to future work that might be accomplished by the Bureau of Mines. The authors desire to acknowledge many helpful suggestions and comments from Paul M. Tyler of the Bureau of twines and from Harris F. Sherman, secretary of the National Building Granite Quarries Association. Miss A. T. Coons of the Bureau of Mines rendered valuable, assistance through her wide knowledge of granite statistics.

Jan 1, 1931

"Option pricing is used in finance for valuing options to buy (or sell) shares at some future date because it provides a convenient framework for quantifying values subject to uncertainty. As one of the main sources of uncertainty in mining is the price (sales) of the metal, this approach can also be used for valuing mining projects.The first part of this paper reviews options and option pricing; the second part presents the approach developed by Brennan and Schwartz (1985) for using option pricing to value natural resources. Several applications of this methodology have been published; these are described. From a mining point of view, the assumptions made by Brennan and Schwartz are too simplistic. The weaknesses are discussed with a view to improving an apparently promising new way of assessing the value of projects. IntroductionThe collapse of the British merchant banking group, Barings, has highlighted the risks that can be incurred by speculators and arbitragers in the futures and options markets. But this negative attention on futures and options should not make us forget their positive aspects. They can provide producers and consumers of metals with more predictable sales prices. The introduction of the new traded average price options, TAPOS, by the London Metal Exchange in January 1997 is a response to this need. Equally important, the theory that the finance industry has developed for valuing options provides an interesting framework for valuing mineral projects as well. While this paper was being revised, the South African gold mining house, JCI, announced that it was using a methodology based on option pricing for valuing the mineral rights to deeplevel gold resources (see Box 1)."

Jan 1, 1997

By A. Heriba

Cyanide is highly toxic to humans and other organisms. Concentrations of RCN as low as 0.05 ppm can be lethal to fish (Scott and Ingle', 1981). In wet climates and in colder climates where natural degradation is slow, it is becoming mandatory to destroy cyanides in effluents before they can be discharged. The disposal of spent gold ore as tailings from cyanide heap leach processing facilities is a matter of concern to the public, the mining industry, and regulatory agencies. South Dakota mining laws and regulations require that spent ore be neutralized to a suitable level with respect to cyanide before disposal (Durkin, 1990). To safeguard the environment and protect ground-water and surface-water supplies adequately, a reliable test is needed to determine the amount of cyanide in the solid spent ore.

Jan 1, 1993

By Drew Bazil, David Smith, Matteo Ferrucci, David Pittman

The Gateway program will provide additional rail capacity between New Jersey and Manhattan. This paper describes how a 70-foot-deep section of cut and cover tunnel was designed to directly support future high-rise towers. The tunnel will link previously completed tunnel sections under Hudson Yards to future tunnels under the Hudson River. The design aims to minimize constraints on future overbuild and future tunnels, while maximizing constructability within a small worksite. The tunnel will pass under the High Line elevated walkway, next to an active rail yard, and close to a subway tunnel. The design was developed by a tri-venture of WSP, STV and AECOM. WSP led the design of major underground works; STV designed utility relocations and the underpinning concept for the High Line; and AECOM designed temporary in-tunnel systems. Construction is expected to start in 2023.

Jun 13, 2023

By M D. Uttarwar, R R. Yerpude

India is the world’s third-largest producer of coal and is endowed with the fifth-largest coal reserves in the world. Surface mining straddles the entire domain of the Indian coal mining industry, yielding over 88 per cent of production. With continually rising domestic demands, it has to shoulder the responsibility of sustaining the requisite increase in coal production and chasing commensurate stripping targets. Such an ambitious task calls for the deployment of smart technologies. In such a demanding situation, cast blasting of overburden has emerged as a promising alternative for enhancing production and productivity of dragline pits.The cast blasting technique reduces stripping costs significantly as it utilises the chemical energy of explosives in place of mechanical energy to move large volumes of overburden quickly. Proper application of cast blasting not only reduces overall mining costs but also increases coal production. This paper investigates and evaluates the potential of the cast blasting technique, with special reference to dragline pits employing the rehandle method of extended bench. The economic feasibility of the technique is also ensured under different scenarios so that considerable benefits would accrue to the individual surface coalmines. To underline the efficacy of the technique, different cast blasting models have been formulated under a range of operational and economic scenarios that resemble present day practices in India. In order to test for economic variability in the application of the technique, a risk analysis of all the formulated cast blasting models is performed using net present value.CITATION:Uttarwar, M D and Yerpude, R R, 2015. Potential of the overburden cast blasting technique in Indian surface coalmines – a modular approach and its financial implications, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 655–664 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

The rate of liquid copper deoxidation during top blowing of reducing flames has been investigated using a high capacity thermogravimetric unit at 1200 °C. For 1 kg copper samples, it was observed that the rate of deoxidation was proportional to the flow rate of the reducing reagent (H2 or CO). Under similar experimental conditions, it was found that H2 is more effective than CO even though both have similar thermodynamic potential to deoxidize liquid copper. The rate of deoxidation of liquid copper with reducing 0 2/CH4 flames was measured for 0 2/CH4 molar ratios of 1.5 to 2. The deoxidation rate depends on the 0 2/CH4 ratio and decreases as it approaches the stoichiometric ratio (02/CH4 = 2). Estimation of the rate of deoxidation of liquid copper with top blowing flames based on the thermodynamic composition ofH2 and CO in the product gases, agrees well with measured values.

Jan 1, 2007

By T. J. White, R. A. Farnfield

Early computerised blast monitoring equipment consisted of a digital version of the existing analogue machines with, perhaps, a few enhancements. Many additional facilities have since been developed to enable the efficient collection of high quality data. These developments are examined with reference to digital sampling, triggering systems, the storage of complete recordings and signal processing. Recent advances have been made in the use of blast monitoring systems that comprise multiple blast monitoring locations with centralised control and data collection. Software has been developed to help record blast parameters and assess environmental effects. Computer databases have many advantages over their paper counterparts. Data can be easily retrieved and processed. The scaled distances used in the prediction and control of peak particle velocities can be calculated rapidly when the data are obtained directly from a database. Since the whole vibration signal can now be recorded, signal processing can be used to provide information such as signal length, dominant frequency and response spectra.

Jan 4, 1993

By Ivan E. Goodner, Charles H. Fulton

THE subject of the constitution of copper-iron mattes has received considerable attention in recent years by Keller,1 Bolles,2 Hofman,3 and Gibb and Philp.4 Still more recently Friedrich, Röntgen, Wiedmann, Heyn and Bauer, and Leroux have published, in some instances, elaborate researches on the various systems of the sulphides, and the sulphides and their respective metals, which enter into the constitution of mattes, and have added very greatly to the knowledge of the subject. The work of Friedrich has been especially fruitful. But to date no effort has been made to correlate the data obtained in the latter researches and apply then to the study of the product called " matte," which is made in such large quantities by copper and lead-smelters. In this paper we propose to determine, by metallographic and chemical means, the constitution of copper-iron and copper-lead mattes in the light of the recent data above mentioned. We do not discuss copper-nickel mattes or speisses (artificial arsenides). The paper is divided into three sections I. A review and discussion of the various binary systems of the metallic, sulphides, and the binary systems of various metals and their respective sulphides entering into the constitution of mattes; also a discussion of the physical and chemical properties of these sulphides. II. A description of the results obtained from the chemical and metallographic examinations of the samples of copper-iron and copper-lead-iron matte obtained from various plants.

Nov 1, 1908

By Kenneth Eilerts, Vincent Smith

"INTRODUCTION Knowledge of the Phase relations of fluids produced from combination wells 4/ at the pressures and temperatures characteristic of production from natural reservoirs is essential to efficient recovery and refining practice. An accurate sample of the fluid from such wells may be prepared by mixing (in the proportions of the measured gas:liquid ratio) gas and liquid taken from the separator conditions of steady flow; and physical properties of the sample, at significant pressures and temperatures, may be determined with suitable laboratory apparatus for use in the solution of engineering problems. The results of study of sample so obtained and of mixtures of gas and liquid from the separator combined in other proportions are presented in this report. Attention was given in the study to the relationship between the physical properties of what may be regarded as the constituent materials - the gas and liquid taken from the separator - and the properties of mixtures of these constituents. Data obtained for the complete range of mixture Proportions are expected to provide a reference scale for the study of other combination-well fluids produced at different liquid:gas ratios."

Apr 1, 1942

By Walker. P. W. A.

Abstract -The Riviera tungsten occurrence in the Cape Province of South Africa was discovered in October 1979 as a result of stream-sediment panned concentrate sampling. The Cape age granite and late Precambrian Malmesbury Group carbonates and chlorite schists which it intrudes and which host the mineralization are covered by between 10 m and 30 m of Tertiary/Recent alluvium and clay. The scheelite/powellite and molybdenite mineralization occurs in a greisenized granite cupola with an overprint of porphyry-type alteration as well as in minor skarns. The ore reserve is estimated to be 46 million tonnes at an average grade of 0.2160Jo W03 and 0.020% Mo. The deposit is uneconomic at current tungsten prices.

Jan 1, 1994

By Jack Taggart, Chris Barker

Pile load testing strategies for large infrastructure projects and multi-phase building developments have historically justified cost and programme benefits for undertaking advance preliminary and working pile load testing. However, more recently piling and pile load testing strategies have included assessment of the embodied carbon to understand and present the carbon savings that can also be achieved. This paper gives an overview of the factors contributing to carbon and emissions in the construction of bored pile foundations and presents the methodology taken in assessing embodied carbon as part of the pile load testing strategy for a multi-phased building development in London. Potential embodied carbon savings for various bored pile types and load testing strategies are discussed alongside alternatives and other considerations including pile re-use and carbon offsetting to inform continual improvement for future projects.

May 1, 2022

By D. Scott Barr

The Zarafshan/Newmont Joint Venture operates the Muruntau heap leach project, located in the Kyzylkum desert of central Uzbekistan. The mine produces more than 12.4 t/a (400,000 oz/year) of gold from low-grade oxide ore stockpiles adjacent to the Muruntau open pit. It is op¬erated by the Navoi Mining and Metallurgical Combine and is one of the largest gold resources known (Fig. 1). Since commissioning in 1995, total heap leach production has exceeded 21 t (675,000 oz). The joint venture uses four-stage crushing and screening to produce a final product for heap leaching, Merrill-Crowe processing and local refining.

Jan 1, 1998

By M. Murillo, J. Botín

"Mining has always played a key role in the improvement of the quality of life, but also, it has been a source of environmental and social conflict. Despite the great progress in social responsibility and sustainability experienced in recent decades, the public image of mining remains low and mining projects and operations must face growing difficulties and demands, which results in increasing capital and operating costs. In practice, the objective of a mining company is to create value for its shareholders and therefore, the best approach to Sustainability would be to foster those drivers aligning sustainability and shareholders value, this is, the “Business Case for Sustainability” (BCS). Only under this assumption, convergence of corporate strategy and sustainability may be assured. This paper discusses partial results of a Research Project being carried out at the Catholic University of Chile, aiming to develop a social and economic model for the effective integration of the values of sustainable development in the strategy of mining companies and their stakeholders. INTRODUCTION Mining is fundamental for the wellbeing of our everyday life. But as important as these benefits are for humanity, the mining Industry has had negative environmental and social impacts. For these reasons, a closer relationship between “Sustainable Development and Mining” is more necessary than ever. The Brundtland definition of Sustainable development does not have a clear relationship with mining, but it provides the context. Under a strict interpretation of the Bruntlandt definition, stating that “Sustainable development is development that meets the needs of the present without compromising the ability of future generations to meet their own needs” [10], mining would not be sustainable because the minerals are non-renewable resources. However, this research focuses on how mining can contribute to the sustainable development in the territories where the projects take place. In other words, this research follows the publication titled “Berlin II Guidelines for Mining and Sustainable Development” [9], which stated that “A mining project that is developed, operated and closed in an environmentally and socially acceptable manner could contribute to sustainable development. Critical to this goal is ensuring that benefits of the project are employed to develop the region in a way that will survive long after the mine is closed”. The potential conflicts between mining stakeholders arises from the interpretation of the concept “developing, operating and closing a project in an environmentally and socially acceptable manner”, and the impact on the economic objectives of mining companies. Nevertheless, the ability of mining companies to control new demands and expectations of stakeholders has threatened the implementation and continuity of their projects and operations. To deal with these issues this research analyses the “Business Case for Sustainability” (BCS). It refers to the process leading to a business and social-economic environment whereby shareholders value may only be optimum under a business strategy which fully integrates the values of sustainability. In the model proposed, the Business Case will start when the benefits are higher than the costs. Benefits not only associated with efficient use of resources, also benefits associated with avoiding difficulties to continue with the mining projects such as strikes, heavy penalties, loss of investment, and so on."

Jan 1, 2016

By Edgar C. Bain

A NUMBER probably a sizable group of person with a dominant interest in metals maintain contact with the developments in ferrous metallurgy by reading week by week, as time permits, some four or five periodical devoted in considerable part to this field. It seems possible that some of these, like ourself, find it difficult to see the net results of the development day by day in clear perspective, The impression sometimes seems blurred by the uninterrupted succession of so many accounts, or out of focus from the very impact of so many reports of new things enthusiastic, well written, and understandable though they usually are. It is at times almost as though one were trying to observe, from a fastmoving vehicle, objects all too near at hand. Or perhaps this impression is merely a manifestation of our individual hyperopia ; in which case we should content ourself with an observation that it would be more satisfactory on the whole to discuss in 1941 the metallurgical advances of 1930-35 than those of

Jan 1, 1941

It was a pleasure listening to this paper. Gary Works' problems were a lot more extensive than the trunnion bearing problems encountered at the Weirton Steel Division. In our two-vessel shop bearing failures are critical in that with a bearing failure on an operating vessel and the second vessel under rebuild, we are down until the vessel rebuild is completed or the bearing is repaired. The first bearing problem at Weirton occurred after we had been operating three years. The failure occurred during the 8th heat following "bum-in" of the vessel. Immediate steps were taken to change the damaged float bearing without an extensive search for the reason the bearing failed. Once the campaign was run out the bearings were inspected and found to be damaged. Field checks revealed that the bearing pedestals were not properly located and as a result the freedom of the float bearing was restricted. The trunnion pin end to end dimension had decreased due to distortion and deflection in the trunnion ring. These dimensions were within tolerances. The damage to our bearing was similar to that in the exhibits from U.S. Steel-Gary Works. Steps taken to correct what was found in the field checks were as follows: 1. The pedestals were relocated to center the bearings. 2. 4" diameter pins were installed to locate the housing in the pedestals. 3. The bearing pedestals were opened up to allow the bearing housing to move slightly in the pedestal. 4. Lubrication fittings for greasing between the bearing housing and the pedestal were installed.

Jan 1, 1972