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By F. Channier

The paper provides the most recent information on the construction of the AP60 phase 1 plant of Jonquiere which is due to be commissioned and started up in the first quarter of 2013. HSE management on site by RTA, and cooperation with local equipment manufacturers and contractors of the Saguenay-Lac Saint Jean region are highlighted in this section. The AP60 phase 1 Jonquiere plant aims to demonstrate of the AP60 technology at an industrial scale and allows the further developments of the AP60 cell. The advantages of the AP60 cell technology in terms of productivity, power consumption and environmental footprint are also briefly presented in the paper.

Jan 1, 2011

By R. R. Stone

"This paper will examine the role of debt and equity in project financing and will illustrate the impact on the return to the project sponsor of each type. Conventional debt sources will be examined, as will product purchaser advances, foreign export-import bank loans and lease financing. The paper will review guarantees, charges against the project, dividend restrictions and other commitments. It will also discuss various features of sales contracts and the degree to which they can assist in securing financing. IntroductionThe cost of bringing new mining projects on stream is escalating significantly more rapidly than general rates of inflation. Reasons for this include the higher costs of safeguarding the environment and ensuring the health and safety of workers. The need to develop properties in more remote areas is also a significant factor. These higher costs have not been matched by increases in metal prices, making the task of financing these projects ever more difficult. At the same time, the imagination of borrowers and lenders seems boundless, and innovative schemes for financing projects are constantly being unveiled.It is probably safe to say that no two projects have ever been financed in precisely the same way and the number of financing options for any project is limited only by the imagination of the sponsors themselves. The objectives of the project sponsor represent the most important factor in determining the scope of possible financial arrangements. For example, the sponsor may wish to maximize over-all company leverage by isolating each of its projects in separate companies. In so doing, it hopes to facilitate more ventures than would otherwise be the case. These objectives point toward true project financing. Additional objectives may be to develop a number of its properties by joint venture and to reduce the amount of debt on the sponsor's balance sheet. Those sponsors whose objectives include minimizing over-all financing costs will wish to increase the number of financial options and, as a result, will not be so concerned with effecting true project financing. This approach may also provide ""greater certainty that tax benefits are utilized quickly."

Jan 1, 1980

By Zihe Ren, Edouard Asselin, Marcus Tomlinson, Tianbi Zhang, Jing Liu

"Raman spectroscopy is used to quantify the extent of disorder in the carbonaceous matter associated with preg-robbing ores. Previous studies of Goldstrike ores showed that the height and width of the peaks for the “D” (disordered) and “G” (graphite) bands, the so-called “Raman ratio” had a strong correlation to the preg-robbing value (PRV) measured for various ore samples. A brief literature review on Raman spectroscopy as it applies to preg-robbing ores is presented. Further, recent studies, presented here, have shown no correlation between the Raman ratio and the PRV for a wide variety of ores. This suggests that the extent of organic carbon crystal disorder is not the main factor in determining preg-robbing characteristics.INTRODUCTION Preg-robbing may arise from natural carbonaceous materials in the ore. Several mechanisms have been proposed in the past decades including a physical sorption process by the carbonaceous matter, or via the reduction of aurocyanide at the mineral surface (Abotsi & Osseoasare, 1986; Afenya, Osseoasare, & Abotsi, 1983; Tan, Feng, Lukey, & Van Deventer, 2005). Nevertheless, the mechanisms of preg-robbing remain poorly understood. Understanding the nature of the preg-robber is of practical importance for the selection of a suitable treatment process. Fine carbon particles in the ore have been recognized as preg-robbers due to their similarity to the activated carbon used in the carbon in leach (CIL) or carbon in pulp (CIP) processes. Previous research has illustrated that the activated carbon (also referred to as amorphous carbon in some literature) has a much higher absorption ability than pure graphite with high crystallinity (Adams & Burger, 1998). Adams et al (Adams, Swaney, Friedl & Wagner 1996) concluded that carbonaceous matter is largely responsible for the overall preg-robbing capacity of a given ore. However, the mechanism of carbon preg-robbing was still not clear mostly due to the complexity of amorphous carbon and its behavior in different solution matrices, and at different pH and temperature (Adams, 1990, 1993)."

Jan 1, 2017

By W J. Riva

This paper reviews the circumstances that led to the development and construction of a commercial-scale vertical shaft carbonizer at Conmore, Alberta. This form coking process may be regarded as having potential application in other areas. Coal pelletizing offers a promising method of decreasing coal agglomeration costs under certain circumstances. Pellets can be rolled easily from -35-mesh coal, provided that a minimum of -200-mesh coal is present. Bentonite was found to be the best binder and was most effective when added in amounts of about 2 per cent. The water content of the coal pellets was observed to vary from 18 to 23 per cent. As a by-product of this investigation, it seems possible that fine coal could be converted into stoker feed by this process. A short investigation of the effect of heating rate on the carbonization of pellets was conducted. The low maximum heating rates in certain temperature ranges, necessary to avoid crack formation in the pellets as reported by other

Jan 1, 1964

By E. Lee Cameron

Summary Records of the past show that the first mineral production in what is now the Province of Manitoba consisted of salt, obtained about the year 1800 by the evaporation of brine. Also at an early time in our history, the Ordovician limestone at St. Andrews Locks, East Selkirk, and other localities was quarried for use as building scone in the construction of forts and fur trading posts. Both salt and building stone are still produced in Manitoba, although not from the original sources. In addition, there is now a substantial production of a variety of other industrial minerals and their products such as lime, crushed stone, gypsum, peat moss, and bentonite. The annual dollar value of production of the industrial mineral industry in Manitoba is today greater than at any time in our past and is derived from a greater variety of products. At the present time, exclusive of the various gravel pits operated by the Provincial Department of Public Works, twenty companies operating thirty-four separate pits, quarries, or mines are producing industrial mineral raw materials in Manitoba. This paper attempts to outline the development of the industry from its start about 1800 to the present, giving general information on the various materials produced. Some suggestions regarding the possibilities of establishing new industries based on other raw materials are given at the end of the paper.

Jan 1, 1949

By S. Homulos

"Introductory and GeneralTHE Northwest Territories comprise all that region -of Canada lying between Yukon Territory and Hudson bay and north of the 60th parallel of latitude. For purposes of mine .administration the Territories are divided into three districts: Yellowknife, McKenzie, and Arctic and Hudson Bay. Mining recording offices for the respective districts are maintained at Yellowknife, Fort Smith, and Ottawa. The mine inspection for the entire area, and also for Yukon Territory, comes under the Federal Department of Resources and Development. Two mining inspectors are responsible for these inspections: the Chief Inspector of Mines, with headquarters in Ottawa, who makes trips into the north at least twice a year, and a Resident Inspector, stationed in Yellowknife.The Resident Inspector is constantly making inspections of active properties. This involves a considerable amount of air travel as the region is large and properties are widely scattered.Although there has been prospecting and staking of claims in each of the three districts of the Northwest Territories, actual mining has been conducted only in the Yellowknife district, and for purposes of this paper we are solely concerned with that district."

Jan 1, 1952

By H. Bannach

"This paper focusses on what seem to be the leading indicators of prosperity in the minerals industry during this decade: the geographical distribution of deposits, environmental impact, capital allocation and acid consumption. There is a potential for meeting environmental criteria at a reasonable profit margin, but those with limited acid demand within economic range will face hard times to meet growing environmental concerns, resulting in additional mine closures. At the other end, those with old waste dumps who are thinking about smelting capacity additions will need capital influx at a much larger rate than ever before. All things considered, a change should be made in the way the world's copper reserves are computed, because there is a growing need to internalize these effects back to the ore blocks before a meaningful estimate of reserves becomes available.IntroductionThe copper industry has undergone several changes during the past decade, many of which were expected to take place because they rel1ect the economics of ageing mines. However, many others took place that shocked the industry because they were not completely under control. The focus of this paper is to rel1ect on those changes, and on market expectations for this decade that somehow depend on their impact.To review the prospects for new mine developments and expansions from an industry perspective to a full extent, it would be necessary to consider not only the deposits themselves, but also geographical constraints, environmental constraints, labour composition, technology development and use, the availability of capital, ownership issues, and integration within the industry. This paper, however, will concentrate on only some of the key elements that are believed to playa major role in shaping the market in the decade that has just begun. These elements, all interconnected, are:"

Jan 1, 1992

By S. Aram

Product Lifecycle Management (PLM) solutions have been serving as the basis for collaborative product definition, manufacturing, and service management in many industries. They capture and provide access to product and process information and preserve integrity of information throughout the lifecycle of a product. Efficient growth in the role of Building Information Modeling (BIM) can benefit vastly from unifying solutions to acquire, manage and make use of information and processes from various project and enterprise level systems, selectively adapting functionality from PLM systems. However, there are important differences between PLM?s target industries and the Architecture, Engineering, and Construction (AEC) industry characteristics that require modification and tailoring of some aspects of current PLM technology. In this study we examine the fundamental PLM functionalities that create synergy with the BIM-enabled AEC industry. We propose a conceptual model for the information flow and integration between BIM and PLM systems. Finally, we explore the differences between the AEC industry and traditional scope of service for PLM solutions.

Aug 1, 2013

By W. D. Watson

"Early in mine development at Quintette Coal Limited major problems were encountered with the fleets of primary equipment which seriously hampered production. These major fleets (cable shovels, hydraulic shovels, hydraulic drills and electric trucks) have consequently been the focal point of maintenance efforts. Some were prototypes in the Canadian mining scene and brought with them new concerns to test their skills. The problems were studied and the category and areas which were having the greatest impact on the reliability of the equipment were determined. Once defined, priorities were established and a program was initiated which was designed to accomplish a resolution. Resulting from implementation of this systematic approach, over the past three and one-half years, the fleets are now giving good reliability and industry standard availabilities. Along with these significant achievements, cost per operating hour on some of the equipment fleets has decreased substantially and continue a downtrend through 1987. This paper identifies the problems and describes the resolutions. IntroductionIn the early years of the mine development, Quintette Coal Limited (QCL) experienced production shortfalls due to problems with the major excavator and haulage fleets. A large fleet of hydraulic excavators had been purchased, and QCL was among the first northern users of all hydraulic blasthole drills. They were also using some prototype equipment and encountered problems which were not common on other types of equipment or were unknown.Because of these unique problems and lack of experience from other mines to draw on, an analytical approach was taken to areas and associated causes of the delays affecting the availability and reliability of equipment. This was done by dividing the equipment downtime into seven classifications of delays, i.e. maintenance, electrical, hydraulic, mechanical, damage, service and preventative maintenance, and tires; and then each was expressed as a percentage of total downtime. Subsequently each of the delay classification was divided into categories e.g. electrical to six categories - wheel motors, main alternator, relays, cards, no propel, lighting and 24 V system. Then, the basis for further study had been established.From this preliminary analysis of historic records, it was possible to determine the areas which were causing the majority of the downtime. These areas were then analyzed to evaluate causes and to determine possible solutions to the problem s. This paper addresses the major fleets, their problems and eventual solutions. Plea se bear in mind that the over-all objectives were to increase physical availability and reliability."

Jan 1, 1988

By Graham Popplewell

"Modular, predesigned diamond recovery plants have been a feature of the diamond mining industry for more than 20 years. The reasons for the selection of such a design route are contrasted with the alternative option of custom-designed route and the relative merits of the two approaches are discussed. The predesigned, modular plant is shown to be particularly applicable for the smaller operation, whether as part of a diverse alluvial mine, an auditing facility for an adjacent large plant, bulk sampling or a remote installation such as is envisaged in the Canadian diamond industry. The characteristics of the predesigned modular plant are described, as well as the inevitable compromises resulting from the concept. IntroductionThis paper explores the application of predesigned modular plants to the diamond mining industry and contrasts their features with the custom-designed installation .A predesigned modular plant is a self-contained unit, or a number of self-contained units, which, when assembled , make up a treatment facility. This is usually small scale in treatment capacity, although multiple modules may be used to increase over-all throughput.A move toward the use of such plants in the diamond mining industry resulted from the relatively unsophisticated nature of the design , the proven nature of pretested , standard plants and the low cost per tonne of capacity and their specific application in remote locations.The recovery of heavy minerals by dense medium separation (DMS) is intrinsically safe and more efficient than the older methods, such as jigs and rotary pans.All diamond recovery plants feature three distinct sections:• feed preparation• gravity separation, and• final recovery."

Jan 1, 1992

By Quenton Johnson, W. A. Gough, David Carr

"This paper describes the application of the BrainWave Model Predictive Controller (MPC) and Advanced Control Expert (ACE) Advanced Supervisory Control System on the SAG Mill, Ball Mill, and Rougher Flotation cells for a new gold processing line at the Oceana Gold - Haile Gold mine in Kershaw, South Carolina. For this project, ANDRITZ supplied the control system design and programming, operator-training simulator and advanced control. The advanced control was tested against the IDEAS™ dynamic simulator, and commissioned during the startup of the processing plant to help achieve target production as quickly as possible. Operators were able to run the equipment in a consistent and optimized manner from an early stage of the plant operation, increasing efficiency and profitability. MPC is able to reduce process variability beyond the best performance that can be obtained with conventional Proportional Integral Derivative (PID) control methods. MPC is able to optimize the control of processes that exhibit an integrating type response in combination with transport delays or variable interaction, which are characteristic of many gold processes including SAG mill weight control and Flotation cell froth level control. The experience and benefits of applying MPC during the startup of a new gold processing plant are presented in this paper.INTRODUCTION Mineral processing operations present many challenges for automatic process control due to variations in unmeasured ore properties, material transport delays, and non-linear response characteristics. Advanced process control technologies such as expert systems and multi-variable model predictive controllers are often used to improve the control of these processes to increase productivity and recovery efficiency. Typically these systems are applied after the mine has been in operation for a period of time. For this project, a complete dynamic process simulator was developed using the IDEAS platform for the purpose of training operators before the plant was constructed. Operators were able to become familiar with the process and the control system in order to become proficient in the use of the controls before the plant was ready to start. They were able to practice abnormal condition management including startup and shutdown of the process using the simulator and develop complete Standard Operating Procedures (SOPs) for these situations. The simulator was also used to test the control system functionality and operator Human Machine Interface (HMI) configuration to reduce errors and improve the performance of the control system during plant start-up."

Jan 1, 2017

By P. Carlone, A. Astarita, F. Rubino

Cold gas dynamic spray is an innovative technology allowing the deposition of thin metallic layers on a bulk or sheet substrate. Titanium on aluminum deposition is very attractive to the aeronautic industry, due to the enhanced corrosion resistance and wear properties of titanium coating as well as its improved compatibility with CFRP, preserving the reduced cost of aluminum substrate. One main drawback, however, is related to the micro-porosity of the deposed layer, negatively affecting the corrosion barrier performance. In this paper, the effect of selective laser post-treatment on pure grade 2 titanium coatings on AA2020-T3 sheets was experimentally and numerically investigated. Morphological features, microstructure and chemical composition of the treated zone were assessed by means of optical microscopy, scanning electron microscopy and energy dispersive X-ray spectrometry. Microhardness measurements were also carried out to evaluate the mechanical properties of the treated coating. A numerical model of the laser treatment, based on a finite volume scheme, was implemented and solved to simulate the process and discuss the experimental outcomes. Obtained results highlighted the key role played by heat input and dimensional features on the effectiveness of the treatment.

Jan 1, 2015

By Hiwa Salimi, Foley. Stephen R, Loghman Moradi

Common water-miscible organic solvents including DMSO, DMF, methanol, ethanol, acetone and THF in combination with HCl and low concentrations of H2O2 were investigated for dissolution of gold. THF showed the best result demonstrating that gold powder could be completely dissolved in 1.5 hours in 1.0 mol/L HCl and 0.2 mol/L H2O2. No complete gold dissolution was observed for the rest of solvents even after 24 hours. The rate of gold dissolution was measured by dissolving gold wire in THF/HCl/H2O2 mixture. The rate of gold dissolution in optimised condition was 75 g m-2 h-1 at room temperature and significantly increased to 590 g m-2 h-1 by raising the temperature up to 60 oC. Although a THF/HCl/H2O2 mixture showed a slower dissolution rate in comparison with aqua regia, however the applied conditions are considerably milder which is highly promising for gold leaching in an industrial scale.

Jan 1, 2015

By D. J. MacKinnon

"The Canadian Copper Company, formed in 1885, began mining the nickel-copper ores of Sudbury in 1887 and producing nickel-copper matte from its smelter in 1888(1). Although it was quickly appreciated that the separation of nickel and copper (i.e. refining) was critical to the production of a marketable nickel product, refined nickel was not produced in Canada until about 1918. From the beginning of the industry, there was considerable political agitation to refine nickel in the Province of Ontario(2). The companies, however, claimed that the existing processes, viz. the sodium sulphide ""tops and bottoms"" process operated by the Orford Copper Company of New Jersey, U.S.A.(1,3,4) and the carbonyl process(5,6) developed by the Mond Company at Clydach, Wales, were too costly to operate in Canada. Nickel was first refined in Ontario about 1918 when the International Nickel Company opened a nickel refinery at Port Colborne, Ontario(6). Initially, however, the refinery at Port Colborne employed the Orford sodium sulphide process, and the first electrorefined nickel in Canada was produced in 1920 by the British America Nickel Corporation whose mine and smelter were located in Sudbury, Ontario, but whose electrorefinery was located at Deschenes, Quebec, near Ottawa, Ontario. The purpose of this article is to outline the early history of nickel electrorefining and to trace the significant developments which led to the first successful commercial electrolytic nickel refinery in Canada. The development of an electrolytic process for refining nickel is due largely to the efforts of four individuals, viz. Carl Hoepfner, Hans A. Frasch, D.H. Browne and ultimately N.V. Hybinette, and the contribution of each is discussed separately below."

Jan 1, 1999

By P. C. Santos-Munguía, F. Nava-Alonso, O. Alonso-González

"The gold recovery of a Mexican cyanidation plant, in Sonora, has been decreasing due to the increasing presence of gold tellurides. This work presents the results of different processes aimed to recover the remaining gold from the cyanidation tailings of the operation. The cyanidation in the mine is performed at 0.1 g/L NaCN and pH = 10.3, adjusted with lime. The treatments studied in the laboratory with these tailings were: cyanidation at higher cyanide concentration than that used in the plant, cyanidation with oxygen injection, cyanidation with oxygen and lead nitrate addition, and thiourea leaching. The results obtained with each of these treatments are presented and discussed with the final objective of proposing a method to recover the gold associated with tellurium.INTRODUCTION It has been demonstrated that gold telluride is refractory to the conventional cyanidation process and, for this reason, some alternative methods to recover precious metals from tellurides have been proposed. (Zhang et al., 2010). These include cyanidation with modified conditions or the use of non-cyanide leaching agents. This work presents the gold leaching results of tests performed with a sample of cyanidation tailings obtained from a Mexican deposit containing telluride species. The mine exploits a mesothermal deposit with a molar Te/Au ratio of 1, containing also lead, molybdenum, bismuth and tungsten. Gold is recovered from the ore by standard cyanidation, however, lately the gold recovery has decreased, likely due to the tellurium content of the ore. The sample used in this work was the cyanidation tailings of this deposit. It was treated in the plant by cyanide heap leaching (0.1 g/L NaCN, pH = 10.3 adjusted with lime). Some gold remained after the cyanidation and it was thought that this gold was associated with tellurium. The objective of this work was the recovery of the remaining gold from the tailings by an alternative process."

Jan 1, 2017

By A. Diaz, Minera Los Pelambres, C. G. Salinas, G. Leinenweber, F. Diaz, D. Rojas, R. Bernal, O. Jimenez

"Los Pelambres Mine (MLP) is located in the IV Region of Chile, a semi-arid region where water plays a key role in operations as a scarce resource and is vital for the sustainability of human life, animals and ecosystem. The conventional flow meters installed on pipes at MLP can fail to provide an accurate measurement due to corrosion and/or fouling on the inner wall or presence of elements in the water such as acids, salts and suspended solids. Conventional flow measurement methods require the inner diameter to be known, however it is not always possible to assess its real value due to scaling, fouling, corrosion, etc. Here we present a novel methodology to solve these problems, which consists of the measurement of flow by a method that does not require the internal area of the pipes: the fluorescent tracer dilution method. In addition, the fluid velocity can be determined by the transit time of a radioactive tracer method. With the flow rate and velocity, the equivalent area is determined and thus the equivalent internal pipe diameter as well. This methodology was applied in a recirculation pump station, for mineral processing from the El Mauro tailings dam.This work demonstrated adequate correlation between measurements from fluorescent tracers and velocity measurements from radioactive tracers, both of which lead to the assessment of the internal diameter of pipes with scaling. The results of both methods disagree with the data provided by the flowmeter installed on the line due to its miscalibration. This information is useful in validating and correcting the information provided by online flowmeters of all water and solutions transport processes in filled pipes.INTRODUCTIONPresently, the need to optimize water resources is increasingly ever important, due to various reasons such as water scarcity, community empowerment, an increased use of water for mining processes and environmental considerations. Taking into account those main considerations, Los Pelambres Mine decided to focus on water conservation to avoid losses of this vital element. They decided to demonstrate that all of the systems that used water (flow meters, pipes, pumping stations, lagoons, etc) were in good condition and that no evitable loses of this important resource occurred. A plan was proposed to conduct a “hydraulic assessment” of fluid flux and water speed at different points and courses at the mine, with the purpose of obtaining hard data to support, verify and correct the information provided online from specific instrumentation dedicated to those purposes. The final goal was to manage the water resource basin in a sustainable way, based on cross-checked information. The chosen points are representative of the processes present in the mine, such as recirculating water stations at different operating conditions and surface water courses, where the fresh water capture systems operate."

Jan 1, 2016

By A. C. Hnatyshyn

INTRODUCTION THOSE concerned with coal mining operations in Alberta have been asked repeatedly the same question, "Why is mechanization in Alberta proceeding so slowly as to lag far behind the mines in the United States?" This question is often asked in such a manner as to indicate that a severe reprimand is overdue to the mining engineers of this Province for their apparent indifference to the problem of improving their mining operations by increased mechanization. To the average person, unacquainted with mining conditions and problems, mechanization appears to be simply a matter of introducing equipment to load coal underground and, once this is done, substantial economies in operating costs will automatically follow. Invariably, those who have followed this simple reasoning have found, to their regret, that such is not the case and that effective mechanization involves something more than the mere process of introducing loading equipment into a mine. To be effective, any programme of mechanization must take into consideration all operations incidental to the mining, transportation, and handling of the coal from the working face to the tipple, and must utilize equipment which can be best adapted to any peculiar condition or circumstance prevailing in the mine concerned. In the use of such equipment, the net and final result should be an improvement in operating costs of sufficient magnitude to at least return to the operator, over a specific period of years or during the expected life of that equipment, all his investment plus a fair return on that investment.

Jan 1, 1951

By V. Fiedler, H. Lachmund, R. Bruckhaus

"After producing some 50 million tonnes of crude steel the two BOF vessels at Dillinger Hüitte steel plant had to be replaced in 2000/01 due to large deformations. The new vessel design was optimised after a number of theoretical evaluations.Refractory investigations were carried out as well as temperature measurements of the shell to provide a basis for selecting a suitable steel grade. This was found in a DH-GTS development - P420M HT - with high strength at elevated temperatures and excellent weldability and made it also possible to build the vessel without any cooling system.After putting the first vessel into operation the metallurgical results showed no remarkable improvement compared to the old vessel, and were therefore not satisfying. With the help of cold model investigations the arrangement of the tuyeres was modified to improve the flow conditions and the interactions between oxygen jet and the heterogeneous plume of the bottom stirring gas. Further optimisations were obtained by a variation of lance tips and a newly developed lime addition model."

Jan 1, 2004

By G. A. Sutton

"At the San Manuel mine (Arizona, USA), in-situ copper leaching of a copper porphyry deposit was carried out from 1986 to 1999 during underground and open-pit mining. In 1993–1994, well¬field testing of the supergene zone, composed primarily of chrysocolla and copper-rich clay minerals, led to estimates that 52% of the acid-soluble copper (ASCu) could be recovered during in-situ leaching; however, the actual recovery from zone 6, which had the longest leach history, was approximately 42%. Comparing drillcore assay data from holes drilled before and after leaching also indicated an approximate recovery of 42%. The discrepancy between the predicted (52%) and actual (42%) recovery is probably related to several factors, including difficulty maintaining fluid saturation, channelling effects, and gypsum precipitation. ¦ KEYWORDS Copper oxides, in-situ leaching, Modelling, Porphyry, Solvent extraction and electrowinning (SXEW), Well-to-well RÉSUMÉ À la mine San Manuel (Arizona, États-Unis), on a procédé de 1986 à 1999 à la lixiviation in-situ de cuivre d’un gisement porphyre cuprifère pendant l’exploitation minière souterraine et à ciel ouvert. En 1993 et 1994, des essais effectués dans des champs de captage de la zone supergène, composée principalement de chrysocolle et de minéraux argileux cuprifères, ont abouti à des estimations selon lesquelles on peut récupérer 52 % de cuivre soluble dans l’acide (ASCu) pendant la lixiviation in-situ ; toutefois, la récupération réelle dans la zone 6, qui affiche l’histoire la plus ancienne en matière de lixiviation, était d’environ 42 %. La comparaison des données d’analyses de forage obtenues à partir de trous forés avant et après la lixiviation indiquait également une récupération approximative de 42 %. La différence entre la récupération prévue (52 %) et réelle (42 %) réside probablement dans plusieurs facteurs, notamment la difficulté à maintenir la saturation des fluides, les effets de canalisation et la précipitation du gypse. ¦ MOTS CLÉS d’un puits à l’autre, extraction par solvant et extraction électrolytique (SXEW), lixiviation in-situ, modélisation, oxydes de cuivre, porphyreINTRODUCTION in-situ copper leaching at the San Manuel mine, Arizona, USA (Figure 1), began in 1986. It was recognized that some of the copper oxide resource was not economically recoverable by conventional open-pit and heap leach methods using solvent extraction and electrowinning (SXEW) and a high stripping ratio would be required to access part of the resource. At the time, in-situ leaching was becoming popular in the uranium industry, but the approach was virtually unknown in the copper industry, especially at a large scale."

Jan 1, 2019

By W. B. Morrey

"In recent years, the major effort in detonator development has been concentrated on ""non-electric"" systems. Existing types all involve some form of explosive reaction to transfer ignition energy from outside the borehole to the pyrotechnic delay element contained within the detonator. These may be based on low-energy detonating cords having grained or plasticized explosive cores, shock tube energy transmission principals and explosive gas ignition systems. Each has properties of internal and external effects not present in electric conductors.The MAGNADET System introduces transformer coupling into electric blasting circuits. Safety features with respect to current leakage, stray currents of AC or DC source, electrostatic energy and radio-frequency radiation are comparable to ""non-electric"" systems, with advantages in simplicity, speed of hook-up and range of application.The transformer device used is a small ferrite ring or toroid which is an integral part of each specialized detonator. The detonator legwires form the secondary side of the transformer winding. The primary side is a single wire loop common to all units within the circuit. Power is supplied from a frequency-tuned portable exploder with unique circuit-sensing features.The MAGNADET System is expected to have particular application to shaft sinking, raising and tunnelling where the protective features as well as speed and efficiency are critical factors. Applications of the 'MAGNA' booster in quarries, open pits and longhole deck charges offer control over vibration problems and elimination of surface noise.IntroductionFor many years, electric detonators and electric blasting systems dominated surface and underground applications where controlled delay times were required. Control over the instant of detonation by blasting machines or power-line switches is the major safety feature.Electrical energy exists in many forms. It may originate from many sources. Electrical energy can be difficult to contain. It may enter or escape through a variety of conductive paths. It may fluctuate, concentrate or dissipate to pose a most elusive potential hazard."

Jan 1, 1982