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By W. A. Mudge

This discussion will be limited to malleable, commercially pure nickel and some high-nickel alloys, containing more than 50 per cent of nickel, which are produced by The International Nickel Company, Inc. at its Huntington works, West Virginia, from electrolytic nickel or from a nickel-copper sulphide matte. The principal sources of nickel are sulphides of nickel, copper and iron, which are found in the large deposit of pyrrhotite-pentlandite-chalcopyrite ores in the Sudbury area of Ontario, Canada. Pentlandite, a complex nickel-iron sulphide, is the nickel carrier. These ores are concentrated, roasted, and smelted to remove considerable iron and sulphur and to produce a nickel-copper sulphide matte. Separation of the component sulphides of this matte, followed by electrolytic refining, results in the production of electrolytic nickel and electrolytic copper; direct refining of a selected portion of the matte gives the nickel-copper alloy, Monel. FUNDAMENTAL OPERATIONS Melting of the metallic materials is done in natural gas-fired, acid furnaces of the open-hearth, or reverberatory, type, having capacities of 6 to 20 tons; in three-phase, basic, electric-arc furnaces, having capacities of 7 to 20 tons; and in basic, high-frequency induction furnaces having capacities of ½ to 3 tons. Malleable, commercially pure nickel is melted in the acid open-hearth furnace. The charge is sulphur-free, electrolytic nickel, containing 99.9 per cent nickel* and clean mill scrap. Monel, containing approximately two thirds nickel and one third copper, is produced by roasting the nickel-copper sulphide matte to an oxide, smelting the oxide with charcoal in a 20-ton, acid open-hearth furnace, adding clean mill scrap, duplexing to a 20-ton, basic, electric-arc furnace, and refining in this furnace with a lime-fluorspar, carbide slag. Inconel, containing nickel, 80 per cent; chromium, 14 and iron, 6, is melted in the 7-ton electric-arc furnace or the 3-ton induction furnace. The charge is electrolytic nickel, ferrochromium and clean mill scrap. These are the fundamental operations. High-nickel alloys are produced from one of these three materials by additions of suitable amounts of manganese, aluminum, silicon or copper. For example, the age-hardenable alloy, K Monel, is produced from Monel by the addition of approximately 3 per cent of aluminum, and D nickel is produced from nickel by the addition of approximately 4.5 per cent of metallic manganese. For conversion to rods, bars, sheet, strip, tubing and wire forms, by hot-working and cold-working operations, the molten materials are teemed into ingots ranging in size from 14 by 14 by 60 in., 3300 lb., to 36 by 36 by 48 in., 18,000 lb. All ingots are overhauled mechanically before hot working.

Jan 1, 1946

By Francesco Chiappalone, Miriam Piemontese, Lance Waddel, Paolo Perazzelli, Emidio Tamburri, Roberto Schuerch

The Three Rivers Protection & Overflow Reduction Tunnel is part of the Long-Term Control Plan of the City of Fort Wayne, Indiana (USA). The 4.9 m internal diameter tunnel, of length approximately 7.5 km, is excavated at a depth of approximately 40–60 m through carbonate rocks using a slurry TBM. Due to the high hydraulic conductivity of the rock mass and the high in-situ ground water pressure (up to 6.5 bar), the management of the water inflow during the TBM advance and standstills, represents the major challenge for the project. This paper outlines the geotechnical conditions and the hazards related to the large water inflows expected in the pre-excavation phase and discusses the experience gained during the construction of the first 8,224 feet (2,507 m), (first third of the total length of the tunnel).

Jun 13, 2021

By R. Dillinger

In the environmentally conscious social atmosphere today, reclamation in surface mines has become a main issue to the public and the regulatory committees. In response to this increased attention, many regulatory committees have begun to enact more stringent regulations on surface mining operations. Operations across all spectrums of the industry have seen changes. Recently and most visibly the mountain top removal mines have seen several new regulations focusing on environmental protection. Specifically regulatory committees have emphasized a focus on the methods of reclamation and recovery of layers suitable for vegetation. These layers are the most visible once the operation has concluded. Also, these layers have the most human interaction (farming, hunting, and house development). Often times the new regulations enacted are shifting from a performance base to a standards base. The key differentiator being a performance base dictates the final result while a standards base dictates the method to achieve the result. The very nature of many regulations (especially those that are standards based) not only challenges the physical limitations of the equipment used today, they come with a financial impact. For the purpose of this paper, the model will be a surface coal operation, utilizing draglines as primary overburden movers. The coal seam is ten feet thick, the overburden ninety five feet thick, the pits are 150 feet wide, and the dragline is a Bucyrus Erie 1570.

Jan 1, 2011

By V. N. Kolesnikov

The Sikhote-Alin part of the Circum-Pacific Ore Belt is characterized by wide distribution of Sn, Pb, Zn, W; Au, Ag, and other mineralization. This mineralization is regionally associated with the Late Cretaceous-Tertiary East Sikhote-Alin volcanic belt where it overlaps the Taukha accretiollary-wedge terrane of the Early Cretaceous age. The Pb-Zn deposits of the Dalnegorsk ore district may be grouped into the skarn (about 80%) and vein types. The skarn deposits are of major commercial value. Their geological position is controlled by the carbonate units located within tectonic melange of the Taukha terrane. Some other lithological and tectonic factors also play a significant role ill distribution of the mineralization. The ore bodies are traced to the depth of 1000-1500 m below the surface, having a pipe-lens shape and vertical zonation. Major minerals of the ores are galena, sphalerite, pyrrhotine, chalkopyrite, hedenbergite, quartz, and calcite. The minor elements of the Pb-Zn mineralization are cadmium, silver, bismuth, and copper. The paper describes relationships between mineral suites and minor element contents in the ores, as well as their significance for processing the ores. The metallurgy applied allows high recovering of the major components (Pb -93.9%; Zn -91.4%). However the tails contain some minor components that may be of commercial interest.

Jan 1, 1998

By William D. Macdonald

The Upper Devonian Kettle Point black shale of southern Ontario is poorly exposed. Structural maps pre-pared from the data of numerous wells show that the upper surface of the formation has low regular relief, and that the lower surface reflects domes in the Middle Devonian and also local subsidence of the Devonian rocks due to solution of salt in the Silurian Salina Formation. The appearance of minor amounts. of marcasite, pyrite, and calcite, m that order, as interpreted from the evidence of concretions from the type locality at Kettle Point is thought to have been influenced by a rise m the pH within anaerobic sediments preceding compaction.

Jan 1, 1960

By William R. Yernberg

Santa Fe Pacific Gold, headquartered in Albuquerque, NM is expanding its operation at the Twin Creeks Mine in Nevada. The $250-million sulfide expansion project, including the Sage Mill, is under construction and is 80% complete. Also, additional mining equipment has been purchased to haul the sulfide ore to the mill. With the expansion, employment at Twin Creeks is expected to reach approximately 970 people by the end of 1996. Santa Fe Pacific Gold now owns and operates three gold mines in the United States and is involved in several other gold projects. The three currently operating mines are the Twin Creeks, Mesquite and Lone Tree mines. The Mesquite Mine is located in California’s Imperial Valley. Lone Tree is located 55 km (34 miles) southeast of Winnemucca, NV. The company’s total gold production from these operations is expected to be in the range of 26.3 to 26.6 t (845,000 to 855,000 oz) in 1996. This compares to a total production of about 124 kg (4,000 oz) for the company in 1989. Production costs range from $6.90to $7.25/g ($215 to $225/oz). At the end of 1995, the company reported proven and probable reserves of 556.7 t(17.9 million oz) of gold.

Jan 1, 1996

By N. E. Lehman

Cordilleran metamorphic core complexes in the southwestern United States are areas where middle to late Tertiary low-angle normal faulting has uncovered rocks that were at temperatures sufficient for mylonitization during the early part of Tertiary extensional faulting. Large-displacement low-angle normal faults that separate upper-and lower-plate rocks in metamorphic core complexes are termed detachment faults. The significance of Tertiary detachment faulting in the Basin and Range Province has only become apparent in the past 6-8 years, and the association of mineral deposits with detachment faults has only been recognized in the past few years as well. Crystalline rocks below detachment faults have typically undergone chloritic alteration and brecciation over a distance of a few to a few hundred meters below the fault surface (Fig. 1). Chloritic alteration and brecciation overprinted mylonitic fabrics formed during earlier ductile shearing along the down-dip projection of detachment faults. Rocks that underwent pre-Tertiary ductile deformation and prograde metamorphism were subjected, in rapid succession, to middle to late Tertiary mylonitization, brecciation and chloritic alteration, microbrecciation immediately adjacent to the fault, and subaerial exposure. Lower-plate rocks thus experienced rapid decompression and cooling as a result of tectonic denudation and isostatic uplift (Wernicke, 1981; Davis, 1983; Davis et al., 1986).

Jan 1, 1987

By Heithecker R. E.

In June 1933 the Bureau of Mines, in cooperation with the State of Oklahoma and the Oklahoma City Chamber of Commerce,, published a report of the gas reserves in the Oklahoma City oil field3/ based upon data as of October 1932, at which time there were 43 classified gas wells in the field, The estimates were obtained by the ?porosity-area" method. There are two general methods of estimating natural-gas reserves. The porosity-area method, as used by Hill and Rawlins, is used when a gas field is comparatively new but after enough drilling has been done to determine the average thickness, porosity, and areal extent of the producing horizon. The "pressure-volume? method of estimating gas reserves, the method used in this report, may be used after a sufficient volume of gas has bean withdrawn from the reservoir to cause an appreciable decline in reservoir pressure.

Jan 1, 1937

By H. E. Stamm, H. H. Spain, R. C. Rumble

This paper presents a reservoir analyzer study of the performance of the Woodbine formation in the East Texas basin. The study was made possible by the compilation of available information on the configuration. thickness and the pressure drawdown of the formation. The investigation was made of the pressure variations in the basin incident to production from the several Woodbine reservoirs. In addition, the apparent compressibility of Woodbine water was evaluated so that the potential water yield of the formation could be determined. The distribution of permeability of the Woodbine sand and the interference between producing areas were also investigated. In conjunction with this basic study of the Woodbine sand, an acceptable match of the production-pressure relationship in the East Texas Field was established on the analyzer. INTRODUCTION When production is taken from a reservoir contiguous to an aquifer, the resultant pressure gradient causes a water influx into the reservoir. For some years it has been the practice to predict the performance of water drive reservoirs with mathematical equations that relate the water influx into reservoirs to their pressure behavior. A rigorous solution of these equations is quite complex: hence, the conventional method requires the simplifying assumptions that the formation have constant thickness, permeability and poiosity, and that it have a known and regular shape. It is necessary to use performance records of the reservoir in question to determine the equation constants that make the results of the mathematical calculations duplicate the reservoir history. The values of the constants determined in this manner sometimes differ so greatly from theoretical or measured values that the constants appear unreasonable. The equation constants comprise such factors as the thickness, porosity and permeability of the formation, and the viscosity and compressibility of water. Usually the thickness, porosity and viscosity are known within a reasonable degree of certainty. whereas the formation permeability and the water compressibility are known with considerably less certainty. Hence. permeability and compressibility values are arbitrarily selected that will make the mathematical equations duplicate the reservoir behavior. In many reservoir studies the value of the compressibility of water thus selected has exceeded the reported value by a factor of from severalfold to manyfold. Whether this excessive value results from the inadequacy of the mathematical approach to take into account the shape irregularities and the heterogeneities of the aquifer, or is due to some type of formation compaction and decrease of porosity has not been established. Because of the significance of the potential water yield of formations with reference not only to oil reservoirs but to water resources as well, it is very important that a representative value for the effective water compressibility be determined. One of the best known examples of a field for which it has been possible in the past to predict the future reservoir pressure is the East Texas Field. Until about 1943 it was possible by means of mathematical equations to duplicate past pressure behavior and to predict with a high degree of accuracy the reservoir pressure of the field. Since 1943, however, the calculated pressures have deviated progressively from the observed pressures to such a degree that in recent years, it has

Jan 1, 1951

By H. H. Spain, R. C. Rumble, H. E. Stamm

This paper presents a reservoir analyzer study of the performance of the Woodbine formation in the East Texas basin. The study was made possible by the compilation of available information on the configuration. thickness and the pressure drawdown of the formation. The investigation was made of the pressure variations in the basin incident to production from the several Woodbine reservoirs. In addition, the apparent compressibility of Woodbine water was evaluated so that the potential water yield of the formation could be determined. The distribution of permeability of the Woodbine sand and the interference between producing areas were also investigated. In conjunction with this basic study of the Woodbine sand, an acceptable match of the production-pressure relationship in the East Texas Field was established on the analyzer. INTRODUCTION When production is taken from a reservoir contiguous to an aquifer, the resultant pressure gradient causes a water influx into the reservoir. For some years it has been the practice to predict the performance of water drive reservoirs with mathematical equations that relate the water influx into reservoirs to their pressure behavior. A rigorous solution of these equations is quite complex: hence, the conventional method requires the simplifying assumptions that the formation have constant thickness, permeability and poiosity, and that it have a known and regular shape. It is necessary to use performance records of the reservoir in question to determine the equation constants that make the results of the mathematical calculations duplicate the reservoir history. The values of the constants determined in this manner sometimes differ so greatly from theoretical or measured values that the constants appear unreasonable. The equation constants comprise such factors as the thickness, porosity and permeability of the formation, and the viscosity and compressibility of water. Usually the thickness, porosity and viscosity are known within a reasonable degree of certainty. whereas the formation permeability and the water compressibility are known with considerably less certainty. Hence. permeability and compressibility values are arbitrarily selected that will make the mathematical equations duplicate the reservoir behavior. In many reservoir studies the value of the compressibility of water thus selected has exceeded the reported value by a factor of from severalfold to manyfold. Whether this excessive value results from the inadequacy of the mathematical approach to take into account the shape irregularities and the heterogeneities of the aquifer, or is due to some type of formation compaction and decrease of porosity has not been established. Because of the significance of the potential water yield of formations with reference not only to oil reservoirs but to water resources as well, it is very important that a representative value for the effective water compressibility be determined. One of the best known examples of a field for which it has been possible in the past to predict the future reservoir pressure is the East Texas Field. Until about 1943 it was possible by means of mathematical equations to duplicate past pressure behavior and to predict with a high degree of accuracy the reservoir pressure of the field. Since 1943, however, the calculated pressures have deviated progressively from the observed pressures to such a degree that in recent years, it has

Jan 1, 1951

By Kevin Andrews, Zach Agioutantis

Analysis of Coal Pillar Stability (ACPS) software, released in 2018, integrates numerous empirical pillar design techniques. The ACPS program incorporates methodologies originally available as design tools from the National Institute for Occupational Safety & Health (NIOSH), including Analysis of Longwall Pillar Stability (ALPS), Analysis of Retreat Mining Pillar Stability (ARMPS), Analysis of Multiple Seam Stability (AMSS), and concepts including Coal Mine Roof Rating (CMRR), the Mark-Bieniawski pillar formula, and pressure arch loading. The design methodologies that are the basis of ACPS were developed via analysis of significant amounts of real-world data and have been standards of the United States coal industry for decades. While there are empirical factors built into ACPS, making it ideal for use in U.S. coalfields, the concepts in the program have proven to be applicable in variable mine settings, and the software was developed to allow for user-based, site-specific modifications of key design inputs. Application of ACPS to cases outside the regions for which it was developed must be approached carefully, and continuous development of site-specific data is mandatory. A case study is presented involving the application of ACPS to assess pillar stability and assist future design for an underground lignite mine in Eastern Europe. Assessment of in-mine observations, review of the geology of the lignite mine, and evaluation of specific conditions associated with a failure event resulted in “calibration” of key input factors to ACPS. Scenarios evaluated with ACPS suggest that pillar strength and overburden depth are key factors for the determination of pillar stability and design in future areas.

Jun 25, 2024

By R Castedo, P Segarra, I del Castillo, L M. López, J A. Sanchidrián

This work investigates some suggested methods for blast vibration monitoring on a hard surface based on 53 tests on a vibration exciter. Errors in the measurement attributable to coupling have been described as function of frequency by the rock-to-mount (or coupling) transmissibility, ie ratio of the velocity of the vibration sensor mount to the velocity of the rock motion. Transmissibility has been measured from 2 to 200 Hz, at two vibration levels (5 and 20 mm/s), in four seismographs. Attachment methods with an anchor, thermal adhesive and gypsum plaster allow stiff rock-to-mount coupling. They ensure accurate measurements (errors below 0.3 dB) for frequencies commonly found in blasting (below 100 Hz) irrespective of the mount characteristics and the vibration level. Free laid mounts and sandbagged vibration sensors lead generally to a poor, weak coupling. Errors are non-linear errors with the input velocity, ie the operating frequency window narrows as the velocity of the ground increases. Free mounts follow ground motion acceptably well (error up to 0.4 dB) at both vibration levels and frequencies below 15 Hz. At higher frequencies, free mounts lead to the largest distortions with expected errors ranging from 0.8 to 6.6 dB. Sandbagging limits the expected errors below 1.3 dB, but it does not prevent large errors that can be up to 4.5 dB. Both frequency and velocity should be considered together to assess the measurement errors instead of the expected accelerations, as it is currently made.CITATION:Segarra, P, Sanchidrián, J A, Castedo, R, López, L M and del Castillo, I, 2015. Effect of vibration sensor mounting method on the quality of vibration measurements, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 545–552 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

By Robert Vinson

This article examines the spatial variability of dust concentrations within a coal miner?s breathing zone and the impact of sampling location at the cap lamp, nose, and lapel. Tests were conducted in the National Institute for Safety and Health Pittsburgh Research Laboratory full-scale, continuous miner gallery using three prototype personal dust monitors (PDM). The dust masses detected by the PDMs were used to calculate the percentage difference of dust mass between the cap lamp and the nose and between the lapel and the nose. The calculated percentage differences of the masses ranged from plus 12% to minus 25%. Breathing zone tests were also conducted in four underground coal mines using the torso of a mannequin to simulate a miner. Coal mine dust was sampled with multi-cyclone sampling cans mounted directly in front of the mannequin near the cap lamp, nose, and lapel. These four coal mine tests found that the spatial variability of dust levels and imprecision of the current personal sampler is a greater influence than the sampler location within the breathing zone. However, a one-sample t-test of this data did find that the overall mean value of the cap lamp/nose ratio was not significantly different than 1 (p-value = 0.21). However, when applied to the overall mean value of the lapel/nose ratio there was a significant difference from 1 (p-value < .0001). This finding is important because the lapel has always been the sampling location for coal mine dust samples. But these results suggest that the cap location is slightly more indicative of what is breathed through the nose area.

Jan 1, 2007

By P. R. A. Andrews, R. K. Collings

"There are more than 300 occurrences of fluorite in Canada. Deposits of economic significance, however, are confined to Newfoundland and Nova Scotia in eastern Canada, Ontario in central Canada, and British Columbia in western Canada. Fluorite has been mined and processed intermittently in Ontario and Newfoundland until November 1990, when Canada&apos;s only producer Minworth Ltd., a U.K. based company, with a mine and concentrator near St. Lawrence on the Burin Peninsula, Newfoundland, closed its operation.CANMET has processed ore samples from each of the major mineralized areas, and thirty-one studies were conducted between 1920and 1970. A summary of the important aspects of the various testwork studies is presented. The production of acid-grade fluorite was possible by flotation, and ceramic-grade, by flotation and gravity concentration methods. Gravity concentration methods included heavy media separation, jigging and tabling. Flotation was by direct and reverse techniques; associated minerals, quartz, calcite, barite, etc. were depressed by a variety of depressants. The function of the major depressants is discussed briefly. The various uses offluorite which include hydrofluoric acid, chlorofluorocarbons, aluminum production, petroleum alkylation, fluxing and ceramic applications etc. are discussed briefly."

Jan 1, 1993

By John C. Machisak

STATISTICAL data on injuries and employment pertinent to metal mines and to their mills, and/or processing plants are presented in this Information Circular for the calendar year 1960. The information pertains to metal mines, as well as ore-dressing plants and primary nonferrous smelters, refineries and reduction plants, and their auxiliary works. These data are voluntarily submitted annually to the Bureau of Mines by the operators, and contribute greatly toward the promotion of safety in the mineral industries. The data presented are classified according to the principal mineral produced and include information on copper, iron, lead-zinc, gold-silver lode, gold placer, uranium-vanadium and miscellaneous metals. A breakdown of miscellaneous metals by commodities is shown in table 19, page 41. The data also relate to workers engaged in production, exploration, development, construction, and maintenance and repair work, as well as supervisory personnel and office-workers at the mine or plant site. Injury and employment data at metal mines and metallurgical plants in the United States for 1960 are shown under the following general sections: 1. General injury experience: Tables I-5-Data on injuries, injury-frequency and severity rates and related employment data, work location, and degree of injury.

Jan 1, 1963

By Ian Bell

This paper investigates fragmentation in an aggregate quarry using the fragmentation-energy fan concept. Six blasts were monitored, located one behind the other in the same quarry area. The rock structure was blocky, the water level and the usage of explosives were variable within and between the blasts. The powder factor above grade was between 0.28 and 0.44 kg/m3 (0.47 and 0.74 lb/yd3). Fragmentation of the plant feed was measured using an online digital image analysis system and three belt scales. The oversize material that was not directly fed to the plant after the blast corresponds to 3‒9.3 % of the total. Data from image analysis was used to build the size distribution in the coarse range (fragments above 120 mm), and the passing fractions at 120 and 25 mm (4.72 and 0.98 in) obtained from belt scales data were used in the range 120‒25 mm (4.72 ‒ 0.98 in) . The non-dimensional percentile sizes between 10 and 90 % for each blast are described through power functions of the powder factor above grade; the model coefficients are statistically significant. From them, using the principles of the fragmentation-energy fan and the Swebrec distribution properties, the fragmentation can be expressed in terms of the powder factor by means of five parameters: the fan focus coordinates and the three parameters of a function of the exponents vs. the percentage passing. The model shows a good capability to describe fragmentation.

Jan 1, 2019

"During the development of a mining project, samples are taken for metallurgical tests. The sample can be a composite sample made of material from a selection of various drilling products or a sample from a mining test. It can be also a sample from an existing plant in order to investigate process enhancement. This sample can represent several tonnes of material which are analysed and split for use in various tests.In the current case, a composite sample of gold ore is dedicated to a Gravity Recoverable Gold (GRG) test. The properties of interest are the head grade of gold, the size distribution of the material, and the gold assay per size class. The sample is mixed and a sub-sample is taken to measure the feed properties: the size distribution and the gold assay per size class. The remaining material of the sample is subject to the first stage of concentration using the laboratory Knelson concentrator. The concentrate is analysed in its entirety, while a sample of tailings is taken for the same analysis. The remaining part of tailings is subject to grinding to feed the second and third stages of concentration. Similar sampling is performed at each stage.The concentration performances are analysed in light of these measurements. But what is the accuracy of the measurements of the properties? Pierre Gy’s theory of sampling, associated with a heterogeneity model built using the GRG test results, will answer this question. The current paper presents, through a real example, the calculation of the errors of the measurements of size distributions and gold assays performed during the GRG test. The uncertainties of the concentration performances and liberation size estimate are then calculated and their impact on the results interpretation is analysed.INTRODUCTIONDuring the development of a mining project, samples are taken for metallurgical tests. The sample can be a composite sample made of material from a selection of various drilling products or a sample from a mining test. It can be also a sample from an existing plant in order to investigate process enhancement. This sample can represent several tonnes of material which are analysed and split for use in various tests. In order to take into account the ore variability in terms of gold deportment, it is recommended to perform variability studies (Dominy, Murphy, & Gray, 2011, Dominy, 2013) using samples representing various horizons or years of production. But for a given ore type, it can be necessary to perform many tests with different operating conditions (Brochot, 2012a). In that case, the variability of the samples is not due to the heterogeneity of distribution of the deposit, but only on the heterogeneity of constitution of the primary sample. The level of confidence associated with the estimated performance parameters is directly linked to the overall error (including sampling error) of the measurements performed during the tests."

Jan 1, 2016

By William M. Dowall

The recently completed in-pit crushing and conveying project at Phelps Dodge&apos;s Morenci Mine is rated among the world&apos;s leading materials handling projects. The operation involves the crushing and transport of more than 109 kt/ d (120,000 stpd) of copper ore, using regenerative conveyors capable of providing more than 5.5 MW (7000 hp) of equivalent electrical energy. The Morenci Mine is located 330 km (200 miles) east of Phoenix, AZ. Phelps Dodge Corp. owns an 85% interest in the mine. The remaining 15% is owned by Sumitomo Metal Mining Co., Ltd. and Sumitomo Corp. Copper has been continuously produced from the Morenci district since the late 1800s. Until 1989, run-of-mine ore was transported from active mining faces to the Morenci and Metcalf concentrators by truck and rail haulage. In that year, a system of in-pit, semi-portable crushing plants and overland conveyors was commissioned. This substantially reduced truck haulage and effectively eliminated rail haulage in the pit. The system used two semi-portable, in-pit crushing stations equipped with 60/89 gyratory crushers. The crushed ore from both plants reported to the first of two overland belt conveyors, arranged in series, for transport from the pit to a coarse ore stockpile. The system was "backed-up" by existing locomotive rail haulage.

Jan 1, 1993

By H. O. Harju

Inco acquired majority interest in the nickel laterite concessions in eastern Guatemala in 1960 and, through its subsidiary Exmibal, extensively explored the deposits until 1965 to define the site for project development on the north shore of Lake Izabal. This paper outlines the exploration methods used to evaluate the Guatemalan laterite deposits.

Jan 1, 1979

By Mike Horn, Keith Meade, Marvin L. Smallwood

Technological changes in programmable logic controllers (PLC)&apos;s and the need to improve the architecture of Mine Wide Monitoring Systems (MWMS) has resulted in the design of a PLC based system at the Virginia Division of Island Creek Coal Company. The system which is presently in the installation phase, is a joint effort of Island Creek Coal Company, Westinghouse Electric Supply Company and Mining Controls Incorporated. The system uses an ethernet based network for graphic display of system data operating under the Genesis software package. Telemetry for the system utilizes the Seimens/Westinghouse L1 network operating over two twisted pairs. Remote telemetry uses fiber optic links and modems operating over standard telephone lines. 500 and 2000 series PLC&apos;s provide distributed data processing for the system with hierarchial processing operating under the Genesis software on the ethernet network for individual mine site monitoring along with the remotely located division office monitoring. System control and data acquisition is provided for underground MWMS operations and on the surface for a vast methane gathering system that is used for degasification of the mines and collection of pure methane for sale to the Columbia Gas Company as natural gas. The inability of industrial MWMS companies to keep up with the vast changes in technology, along with economic considerations associated with expanding the existing MWMS created the need for the development of the PLC based system to replace the older industrial monitoring systems.

Jan 1, 1993