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By Arthur R. Still, Paul Gilmour

The ore deposit of the Iron King mine occurs in a group of steeply-dipping metamorphosed eugeosynclinal volcanic and sedimentary rocks of Precambrian age. Within this sequence, the ore deposit lies at the contact of a unit made up of rhyolitic tuff and interbedded andesite and a structurally underlying series consisting of andesitic tuffs, minor rhyolitic tuffs, and argillaceous sediments. Field evidence suggests that these rocks have been overturned. The ore deposit is made up of a series of overlapping, conformable or bodies consisting of massive pyrite and associated lenses of massive quartz. These contain recoverable amounts of gold, silver, lead, zinc, and copper. A parallel zone of copper mineralization occurs within the hanging-wall rocks. The deposit is considered to belong to a large and important group characterized by mineralogical composition and the lithology and structural type of the host rocks. Evidence regarding the origin of the deposit is reviewed, and it is concluded that the ore bodies were formed through the agency of volcanic hot springs on, or near, a submarine surface of deposition

Jan 1, 1968

By Larry: McAnuff Schneider, Edward Walter, Gordon Shaw, Daniel Grieco, Dennis Clark

During the 1998 Annual Conference of the International Society of Explosives Engineers (ISEE), the Seismograph Section established a subcommittee for the purpose of compiling a list of all regulations pertaining to limits imposed on ground vibration generated by blasting. The goal of this project was to determine the vibration regulatory levels being enforced, with the further intention of examining their scope, and uniformity. A secondary purpose was to evaluate the consistency of the existing regulations with the current scientific findings on structural response and damage potential.

Jan 1, 2001

By Robin G. Adams

The market prices received by producers of internationally traded commodity metals have been, and continue to be remarkably volatile and unpredictable compared with most other traded goods and services. This volatility results in an erratic financial performance on the part of producing companies, disruptive and often inflationary cost changes for consumers, unreliable tax revenues and export earnings for host governments and severe social and economic pressures on local, sometimes remote, communities which are dependent on the activity in question. Generally speaking, price volatility appears to be associated with the inability of the metal producing side of the industry to regulate the volume of supply in a manner that is consistent with metal demand, which in turn reflects broad macroeconomic and industrial developments around the world. This statement does not purport to apply to all metals or to all instances of volatility of course. Price movements may occur as a result of pure speculation or even illegal manipulation of the commodity markets. Embargoes, boycotts and other politically induced supply changes may contribute. Threatened or actual strikes also cause artificial swings in sales volumes and prices. How- ever, most of these developments are of a short-term nature. Yet metals price cycles may last for several years, as demonstrated by the extended copper price trough from 1981 to 1986. This paper deals with price volatility which reflects long-term economic cycles and the adaptive processes that exist within the industry in response to such cycles. Special emphasis is placed on the role of forecasts and forecasters in these processes. It should be said at the outset that this reflects the personal experience of one forecaster working in private sector commercial consulting practices that are independent of producers, consumers and host governments. However, the experience does cover the entire period since 1973 and has involved working with a substantial majority of the major companies that supply high volume commodity metals. By way of background it should be stated that the post-1973 world economy has provided a challenging environment for forecasters. One cannot be precise about the forecasting record of either industry insiders or outside consultants, financial analysts and academic forecasters because comprehensive records have not been kept, or if they have the results are too embarrassing to be published. Institutions such as the World Bank have published forecasts of the prices of major commodities on a regular basis and these have, presumably, had some influence on financing decisions in the industry. This record along with our own experience and numerous discussions with metal producers, major consumers and host governments permits certain generalizations to be made. The most important of these is that during the early 1980s. from about 1980 through 1985/6, the forecasters system- atically and substantially over- estimated metal prices. While some fore- casters did correctly anticipate a recession in the early 1980s and some consequential decline in prices, the magnitude and duration of the decline was far greater than anyone foresaw. This systematic forecasting "failure" appears to have occurred independently of the forecasting methodology employed. Moreover, its extent cannot be explained by obvious factors such as incorrect macroeconomic assumptions. There appears to have been some kind of structural change in the world mining and metals industry over this period

Jan 1, 1989

By Dave Bulled

"This paper describes the design of a molybdenite flotation circuit using FLEET technology applied to kinetics data produced from laboratory flotation testing and distributed across the blocks of a mine plan using a geostatistical approach. The geostatistics assigned the statistical error that arises from having a limited amount of sample testing data to the kinetics estimates of each block of ore in the mine plan. The final design then included a quantification of risk based on the accuracy of the block flotation kinetics and model fitting. The design made reference to the extensive technical reports describing earlier metallurgical test work including some pilot plant work over thirty years ago.The testing involved conducting MinnovEX Flotation Tests (MFT) to determine the rougher flotation kinetics at the specified reagent conditions and rougher-cleaner tests to determine the change in kinetics resulting from regrind. These flotation kinetics were used within FLEET simulations to create a full-scale flowsheet and plant design including recommended equipment sizes and the forecast of operating results. Measurement of detailed flotation kinetics for a wide range of samples allowed the effect of size of grind and efficiency of classification (i.e. width of size distribution) to be predicted for the whole ore body.INTRODUCTIONAdanac Moly Corp. proposed to develop a 20,000 ton per day mill to produce high quality molybdenite concentrate from its Ruby Creek resource in north-western British Columbia. It is a relatively clean low grade porphyry-monzonite occurrence containing minimal quantities of other sulphides such as chalcopyrite, pyrite, sphalerite and galena. Molybdenite occurs mainly as coarse flakes with lesser amounts of finer sized values. An optimum plant design was required to can achieve the predicted operating results, at a known level of risk, while treating the variability inherent in the ore body."

Jan 1, 2007

By Lijun Xu, Jan M. Mutmansky

"Mutmansky, J.M. and· Lijun Xu, 1989. Some observations on particulates collected in underground coal mines using diesel and non-diesel equipment. Min. Sci. Technol., 9: 207-218.The results obtained when sampling twenty underground coal mine sections, each in a different mine, are outlined. The sampling effort was oriented toward a detailed characterization of coal mine dusts and thus eight-stage Anderson Model 298 impactors were used as the primary collection instrument. This instrument allowed a fairly detailed size distribution for each of the particulates sampled. Because four of the mines used diesel outby equipment and/or diesel shuttle cars at the face, it is possible to make some comparisons of the particulate distributions in diesel versus non-diesel mines.One of the more interesting results is the pattern that exists in mines lising diesels only for outby utility haulage. Particulates in these mines seem to be consistently heavy in the fine size ranges, perhaps being of significant concern to the industry. While no definite conclusions can be drawn from the limited data, a more detailed study of particulates may provide a better picture of particulate loadings.IntroductionThe subject of particulate emiss1ons from underground diesel equipment is currently a very important topic as health concerns and regulation of diesel particulate emissions have created new environmental problems for mine operators. The amount of particulate matter originating from diesels has not been extensively measured and problems of differentiating coal and mineral dust from diesel particulates make existing data questionable.However, it is necessary to make an assessment of the problem in order to solve it. It is known that particulates from diesel engines are solid aerosols formed in the combustion process. Technically, this places the particles in the category of fumes. It is also known from tests where no mineral dust could be a factor in the measurements that about 90% of diesel particles are less than 1 µm in aerodynamic diameter [3]. To measure the diesel component of a coal/diesel particulate to measure, Johnson et al. [2] have developed procedures for utilizing laser Raman spectroscopy. The determination of diesel content in a coal/diesel mixture is difficult due to the chemical similarity of the two organic materials. However, laser Raman spectroscopy, which is often used for identification of organic materials, has potential if the Raman spectra for the two materials are different and unique. The study concluded that an accuracy of ±~% could be achieved for mixtures containing up to 55% diesel particulate. The method is relatively complex and would need further development for routine application."

Jan 1, 1990

By M Doran

The Olympic Dam mine utilises 1.1 m to 1.4 m diameter raise bores for generating the initial slot void for most production stopes. Slot raise bores generally span two development levels ranging from 30 m to 50 m in height. Raise bores are reamed upward and typically leave a cap of rock equivalent to two times the raise bore diameter on the drill level (minimum 3 m). This provides safe access over the cap for subsequent production activities. It is therefore critical to ensure robust falling object protection for personnel accessing underneath, and in the vicinity of the raise bore void on the lower level. Recently, a number of mesh failures have occurred at Olympic Dam as a result of falling rock from the underside of the cap and raise walls. In addition, as Olympic Dam transitions to deeper and more challenging ground conditions, rockfall-off onto the raise bore protection mesh is anticipated to increase in frequency. This paper discusses the evolution of raise bore protection mesh used at Olympic Dam and presents results from recent site-based drop testing. This impact testing was carried out using a built for purpose object to replicate point loading and shear failure of mesh wires. Testing was also carried out on an improved mesh design which utilises two layers of Geobrugg high-tensile MINAX mesh. Results from the drop testing suggest an improvement in performance of the raise bore protection mesh is realised with the updated design.

Mar 29, 2023

By Raffaella Granata, Wesley Schmutzler, Matteo Bertoni

"The Lower Wood River Levee system, at the confluence of the Wood River Creek and the Mississippi River, in East Alton, Illinois, has been plagued with underground seepage and, in 2010, remediation was deemed necessary by the Southwestern Illinois Flood Prevention District Council and the United States Army Corp of Engineers (USACE). The experts enlisted by the council produced a design that provided for constructing a cutoff wall approximately 2,000 feet long and up to 140 feet deep, through alluvial and outwash soils, and embedded in bedrock. This paper will describe the challenges faced by the Quality Control (QC) and Quality Assurance (QA) teams due to the complex nature of the project in conjunction with an extremely thorough QC/QA program.INTRODUCTIONThe “American Bottom” is an area of 453 km2 (175 square miles) in Southwestern Illinois, extending from Alton south to the Kaskaskia River, which is home to 156,000 people. In the 1940s and 1950s the U.S. Army Corp of Engineers (USACE) designed and built a 120 kilometer (74 mile) long levee system to protect the area from a 500-year flood event on the Mississippi River, which flows through it. The levee system has been plagued by under-seepage for several years. The phenomenon has worsened to varying degrees, depending on location, to the point that remediation was needed.The Southwestern Illinois Flood Prevention District Council (SIFPDC), to obtain Federal Emergency Management accreditation, in June 2010 commissioned a team lead by Amec Foster Wheeler for the design and management of the required levee improvements. The team presented in 2011 the project’s first set of drawings showing proposed design features throughout the levee system. The project was subdivided in four areas, based on the controlling levee districts, one of which, the Wood River Drainage and Levee District, was split into three subdivisions: Upper Wood River, East-West Forks of Wood River, and Lower Wood River.The project included the installation of a cutoff wall at the confluence of the Wood River and the Mississippi River in East Alton, IL (Fig. 1). The Engineer of Record (Amec Foster Wheeler) considered the cutoff wall as the only viable solution to stop the severe under-seepage that was undermining the integrity of the Lower Wood River Levee. The Lower Cutoff Wall (LCW) project is the subject of this paper."

Jan 1, 2017

By Sara J. Davenport

With the increased demand for mercury incident to preparations for national defense and the reduction in imports from some of the usual sources owing to war conditions, many small mines in the United States Pure now being worked that ordinarily would be unprofitable. This is indicated by the following table on mercury produced in the Unite States in 1939-40 (1)4/

Jan 1, 1941

By Joseph W. Johnson

General Electric introduced electric drive systems on 85 ton Off-Highway mining trucks in the early sixties. Due to favorable economics, trucks have increased in size to handle larger payloads. Series Motorized Wheel systems were developed to meet this demand. When the technology was available, General Electric switched from use of Series motors to separately excited motors with the added benefits of static exciters and simplified control. Over 20 years of electric drive experience have been incorporated in the STATEX drive systems, which covers truck sizes from 85 to 220 tons. This paper traces the drive system developments from the early stages to the present and takes a look at what's ahead.

Jan 1, 1983

By T. A. Simpson

The search for ore continued at its relentless pace throughout 1967. Canada, South Africa and Australia plus a few scattered localities on the globe reported minerals finds of significant importance. Many of the reported finds were not high grade ore, but they nonetheless will assist in sup- plying a highly industrialized, mineral hungry world. No longer does inaccessibility and remoteness close an area to mineral exploration and development. The communication and transportation systems of today have closed the gap and, moreover, the demand for essential mineral commodities is causing price shifts which encourage exploitation of deposits heretofore considered uneconomical.

Jan 2, 1968

By Alfredo Huarcayo, Juan Gamboa

Los nuevos desafíos que afronta la industria minera en la actualidad exigen operaciones altamente eficaces y eficientes con altos estándares en seguridad, es así como, la Superintendencia de Ingeniería de Mantenimiento de Antamina en su constante proceso de mejora continua busca optimizar las actividades de Confiabilidad Operacional, mediante el monitoreo de condición, y el cuidado de la integridad del activo, enfocado en la seguridad del personal.

Sep 29, 2023

By Ulf Nyberg, Changping Yi, Daniel Johansson, Håkan Schunnesson

To investigate the non-ideal detonation properties of aluminized emulsion explosive, a series of tests for an emulsion explosive with 5% aluminum powder additive were carried out with mortar confinement. The velocity of detonation (VoD) and the curvature of the detonation front for different charge diameters were obtained from the tests with a high-speed camera

Feb 1, 2020

By N. S. Dalal, Xianglin Shi

"The mechanism of vanadium(V) V ) toxicity is still not fully understood in spite of extensive current effort (1-3). The presence of a vanadium(V) V ) -dependent NAD ( P )H oxidase in cell membranes suggests that at least one of the pathways involves oxidation of NAD(P)H (1-3). Considerable effort has therefore been devoted to finding the mechanism of NAD ( P ) H-oxidation by va¬nadium( V ) (1-19). Recently Liochev and Fridovich (4, 16) provided a critical review of vanadium( V) -stimulated NAD (P )H oxidation by plasma membranes. They out¬lined a mechanism in which vanadium(V) V )-stimulated oxidation of NAD ( P )H by biomembranes involves an O2 - initiated free radical chain reaction (4 ). While the above may be the major pathway for the vanadium-me¬diated NAD (P )H oxidation in membrane-related sys¬tems, some recent results suggest that in the presence of NADPH the flavoenzyme glutathione reductase can function as a vanadium(V) V ) reductase (18). Because of the significance of this result in relationship to the mech¬anism of vanadium( V) metabolism and the novelty of the metal-reductase behavior of a flavoenzyme, we have car¬ried out additional studies on one-electron reduction of vanadium( V) by two other, related flavoenzymes: lipoyl dehydrogenase and ferredoxin-NADPH oxidoreductase. These two enzymes were selected because they are known to catalyze a one-electron reduction of Cr ( VI ) (19-21 ), which is isoelectronic with vanadium( V ).The present study also reports on the generation of hydroxyl ( • OH) radicals in the vanadium( V) -flavoen-zyme redox system without exogenous H2O2. The • OH study was undertaken because • OH radicals are known to be generated in reactions of vanadium( IV) with H2O2 (17,18,22-27). For example, Piette and co-workers (17, 22) have studied effects of vanadium(IV) IV ) on lipid per-oxidation and NADPH oxidation and suggested that va-nadium( IV) -induced • OH radical formation may play an important role in vanadium( V) toxicity. Carmichael (25, 26) investigated the reaction between a RNA /VO 2' complex and H2O2 with a view to probe the possible re-lationship between vanadium( IV) -mediated • OH radical generation and DNA damage. He has suggested that in this reaction the • OH radical adds to the C (5) carbon of uracil, causing nucleotide damage, similar to what occurs in the nucleotide /Fe2+ / H2O2 reaction (28) and in y-irradiated aqueous solutions of nucleic acids (29 ). To our knowledge, however, there is as yet no report on ·OH radical generation in any reaction involving the reduction of vanadium ( V) by a well-characterized enzyme, without exogenous H20 2 • The present study provides evidence that ·OH radicals can form in a flavoenzyme-mediated reduction of vanadium( V) to vanadium( IV) and that this process involves also the reduction of molecular oxygen ( 0 2 ) to H20 2 • The H20 2 thus generated reacts with vanadium( IV) to produce ·OH radical, in analogy with the Fenton reaction ( Fe2 + + H20 2 - Fe3 + + OH- + ·OH)."

Mar 1, 1992

By Sacha Gueronik

El presente trabajo señala la repercusión del CIPEC sobre el precio del cobre en los demás países y en un futuro inmediato, así como describe las relaciones entre la política minera y la política de desarrollo referidos a los países en vías de desarrollo. Para conocer la importancia de dicha institución, es necesario señalar sus funciones y las características básicas entre los cuatro países miembros: Perú, Chile, Congo y Zambia. Posteriormente, se analiza la política de estos países participantes para definir dos objetivos importantes. El primero, señala el aumento de la producción mineral -en tanto haya posibilidad de crecimiento del mercado de cobre- y así crear condiciones favorables para el crecimiento a largo plazo de consumo. Mientras que el segundo, refiere cómo el CIPEC debe afontar el desequilibrio de los países entre las tasas de crecimiento de las exportaciones y de las importaciones a través de cambios rápidos en sus estructuras económicas para facilitar al mismo tiempo la industrialización y el desarrollo de la producción agrícola .

Nov 20, 1969

By Juan Munar Calderon

El presente texto revisa la función de la empresa de comercialización de productos mineros (MINPECO), su importancia en la economía nacional y los principales resultados alcanzados por la comercialización estatal. MINPECO es una empresa encargada de la comercialización interna y externa de productos mineros, cuyo funcionamiento está normado por su ley orgánica, disposiciones legales relativas a las empresas públicas, sus estatutos y los reglamentos internos de la empresa. El sistema actual de comercialización comprende modalidades de compra-venta, contrato de terceros, conversiones y las relaciones financieras. Asimismo se describe el ingreso de divisas y ventajas de la comercialización estatal.

Nov 20, 1978

By Paul O. Malan

"The Tusc gold deposit is located along the Carlin Trend approximately 13 kilometers north of Carlin, Nevada and 2.5 kilometers northwest of the Gold Quarry mine. Tusc is one of several structurally controlled oxide gold deposits located along the Good Hope fault within the Maggie Creek subdistrict. Mining commenced in 1994 with an oxide reserve of780,000 troy ounces of gold at an average grade of 1.34 g/t Au. The Good Hope fault forms the southwestern edge of the Schroeder Mountain uplift (also known as the Carlin Window) and juxtaposes carbonate rocks of the Siluro-Devonian Roberts Mountains Formation against siliceous mudstone, siltstone, and silty limestone of the Devonian Rodeo Creek unit. Submicroscopic gold mineralization is disseminated in the Good Hope fault system and in fractured hanging wall carbonate rocks. Wallrock alteration includes silicification, deca!cification, sericitization, and late alunite replacement and veins. All Tusc ore is transported 2.5 kilometers to Gold Quarry for processing. Leach-grade ore (0.2 - 1.7 g/t gold) is placed on the oxide leach pads, and mill-grade ore(> 1.7 g/t gold) is processed through the CIL oxide mill. IntroductionThe Tusc gold deposit is located in Eureka County, Nevada, U.S. A, approximately 13 kilometers north of the town of Carlin and 2.5 kilometers northwest of the Gold Quarry mine (Fig. 1 ). Tusc is one of several open-pit, oxide, gold deposits within the Maggie Creek subdistrict of the Carlin Trend. Tusc is a structurally controlled gold deposit located along the Good Hope fault. Submicroscopic gold mineralization is disseminated in the brecciated and silicified Good Hope fault zone and along intersecting northeast and northwest striking structures."

Jan 1, 1997

By Paul S. Schopf

The results of an experimental investigation into the possible use of medium energy acoustic fields (130 to 140 dB) to precipitate 1 to 10 micron particles is presented. The aerosol was produced with a LeMer generator using oleic acid and nitrogen. The sound field was a sinusoidal standing wave field in an acrylic tube, with light transmission data used for concentration determination. The results showed collection efficiencies of up to 80% on 2 micron particles with a residence time of 11.8 seconds at a sound pressure level of 139 dB re 2x10-5 N/m2. A discussion of the possible turbulent mechanism is made, as well as review and comparison with others? work.

Jan 1, 1972

By R. E. Murray

"It is a gloomy moment in the history of our country. Not in the lifetime of most men has there been so much grave and deep apprehension; never has the future seemed so incalculable as at this time. The domestic economic situation is in chaos. Our dollar is weak throughout the world. Prices are so high as to be utterly impossible. The political cauldron seethes and bubbles with uncertainty. Russia hangs, as usual, like a cloud, dark and silent, upon the horizon. It is a solemn moment. Of our troubles, no man can see the end." By now you, no doubt, are asking, 'Where did Murray get this bit of philosophy?' Well, I obtained it from an editorial entitled. "The Worst of Times", which was published in the Harper's Magazine in 1847. That's right, 1847! The parallelism between the situation in our country at this time and in 1847 is un- canny. But wait, there is one major exception the size of government. To my knowledge, the citizens of 1847 were not stifled by the extreme governmental excesses that we are experiencing today.

Jan 1, 1980

By Frank J. Wiebelt

As a result of the examination of many copper-zinc properties in the West Belt area of California, nine were chosen for exploration projects by the Bureau of Mines. This was part of the Bureau's wartime mineral-development program aimed at maintaining production of essential metals and increasing ore reserves. The properties explored were the El Dorado, El Dorado County; Copper Hill, Newton, and Gray House, Amador County; Constellation, North Keystone, and Collier, Calaveras County; and American Eagle and Akoz, Mariposa County. In addition to surface sampling and mapping, 41 holes, aggregating 18,134 linear feet, were diamond-drilled. Detailed results of the work done on all properties except the El Dorado and Akoz are given in this report. The El Dorado and Akoz were discussed in Reports of Investigations 3896 and 4144, respectively. Figure 1 is an index map showing the location of the mines covered in this publication.

Jan 1, 1951

By Derek J. Cyr

Climate has an immense impact on the properties of Athabasca oil sands and the ease or difficulty with which it is excavated and extracted. During the winter months, exposed oil sands surfaces freeze. When hydraulic and electric shovels used in the various operations in the Fort McMurray area excavate the benches, large frozen lumps are created. These lumps are either destined for a lump dump where increased costs are incurred due to rehandle, or they are sent to the primary crushers where they can cause significant downtimes by jamming the crusher. The crusher down time can sometimes be in the order of hours of lost production. Studies on data from two consecutive winters at Syncrude Canada?s North Mine show a high correlation between climate and the generation of frozen oil sands lumps. Temperature, ground cover, traffic, bench exposure time, oil sands grade and moisture content all contribute to this problem. A 1D frost penetration model was used to predict the depth of frost expected in oil sands and the corresponding likelihood of frozen oil sands lumps. To combat the challenge of frozen lump generation, a number of proactive and reactive measures can be taken: artificial snow, shallow ponds, scheduling, blasting or ripping.

May 1, 2004