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By A. Majumdar, B. Servière, H. Persson

The CCR refinery, which was built in 1931, treats both internal and third party copper anodes to produce 325,000 mt of copper as cathodes. These anodes contain high levels of impurities, such as Ni, As, Sb and Bi, that reports to the electrolyte during the refining step and need to be removed in order to maintain cathode quality and operating efficiencies. In the purification plant, the electrolyte is de-copperized via electrowinning in three stages. In the last stage, the copper content of the electrolyte is reduced to below 1 gpl in order to maximize the co-deposition of As, Sb and Bi with the Cu. This is accomplished with minimum arsine gas generation by using periodic reversal of the current and by controlling the final copper content of the electrolyte. Nevertheless, the possibility of exposure to arsine is treated as a major risk and controls have been implemented to reduce this risk. This paper describes the controls in place at the purification plant, which are being continuously improved through periodic risk assessments and audits. INTRODUCTION The CCR Refinery, which is a part of Glencore Canada Corporation and located in Montreal-East, Quebec, is a custom copper and precious metal refinery, with a capacity to refine 325,000 tonnes of copper anodes per year. Copper anodes are received from the Horne smelter in Rouyn-Noranda, Quebec, Altonorte smelter in Chile and other 3rd party smelters. CCR anodes are produced using the spent anodes from the tankhouse along with purchased spent anodes and copper scrap. The precious metal plant treats the tankhouse anode slime, purchased anode slime, precious metal ingots and Doré anodes from Glencore’s Brunswick lead smelter in Belledune, New Brunswick. CCR products include copper cathodes, silver and gold bullion, a platinum-palladium concentrate, selenium, tellurium dioxide and nickel sulfate. In 1975 an accident occurred at CCR where two employees were exposed to fatal levels of arsine emitted from the then existing purification cells. This process was therefore shut down immediately. Research and development work was then initiated to determine the optimum electrowinning conditions whereby arsine gas generation would be minimized while maintaining high copper and impurity removal efficiencies. It was found that the application of periodic reversal of current (PRC) during the last stage of electrowinning retarded the onset of arsine formation while at the same time allowing the copper concentration to be reduced to less than 1 gpl (Houlachi & Claessens, 1978). A new purification plant was designed based on the PRC technology and was started up in 1976. In addition to the use of PRC electrowinning, the new plant is located in a fully enclosed section of the tankhouse. A special effort was made to design a ventilation system to evacuate the acid mist in addition to any arsine gas. Arsine monitors were installed to measure the emissions from the stack along with arsine levels in the workroom. The arsine monitors and the ventilation system were interlocked with the rectifiers (Thiriar et al., 1983).

Jan 1, 2019

By Takashi Nakamura, Atsushi Iizuka, Yong Fan, Etsuro Shibata

The level of iron in typical copper slag reaches nearly 40% by mass, in the form of iron silicate. We designed a method to oxidize the nonmagnetic iron silicate to magnetite, permitting the selective recovery of the slag’s iron content by magnetic separation. This would effectively decrease the volume of dumped slag; the reclaimed iron could be used for iron and steel making. The crystallization behaviors of magnetite and hematite were studied as reaction products of the molten oxidation of copper slag. A gas atmosphere of 1% by volume of oxygen was found to effectively precipitate the slag’s iron content as magnetite.

Jan 1, 2015

By D. V. Krefting, D. R. Bennett

"The Cyprus Anvil Mining Corporation established a lead-zinc mine and concentrating plant at Faro in Yukon Territory in 1969. Following some 12 years of continuous operation from a single pit adjacent to the concentrator, the company decided to expand operations into two additional areas on the Vangorda Plateau. The two new deposits, known as Grum and Vangorda, are located some 15 kilometres from the existing concentrator.Confirmation of mining feasibility was followed by determination of the most practical and economical method of transporting the raw ore from the new mine sites to the existing concentrator. This analysis was carried out in two phases. The first phase reviewed the feasibility of alternative transportation systems on an 'order-of-magnitude' cost basis. This work identified systems worthy of more detailed examination. The second phase examined the preferred alternatives in greater detail.Initially, operating principles and parameters were established and catalogued. Then, based on these criteria, complete systems were developed utilizing alternative modes of transportation . In the overview analysis, some transportation modes were judged impractical and discarded, 'order-o f-magnitude' costs were developed for other systems and the most costly were eliminated . In the detailed study, the favourable systems were examined in depth which required development of accurate capital and operating costs, consideration of environ- mental impacts and an assessment of intangibles associated with the operation of a new development."

Jan 1, 1984

By Bryon Bisiaux, Walter Valery, Sonny Mwansa, George Amonoo, Adrian Dance

"Newmont Ghana Gold Limited’s Ahafo operation have been working with Metso Process Technology & Innovation (PTI) since early 2009 to increase mill throughput from a combination of controlled blasting practices and optimised primary crusher and grinding circuit conditions. For such Mineto-Mill projects, PTI’s methodology is termed Process Integration & Optimisation (PIO).Ahafo operate a SAG mill, ball mill and pebble crusher (SABC) circuit that processes a range of primary ore of varying hardness from different pits which is blended with soft oxide material. The PTI study focussed on ball mill limited material from the Apensu open pit.Following a benchmarking study of all blasting, crushing and grinding practices in January 2009, PTI recommended changes in both blasting and crushing conditions in order to generate a finer feed size to the SAG mill. Additional operating changes in the grinding circuit were recommended.A series of trials were conducted in November 2009 where three blasts were fired using a different blast design (hole diameter and explosive type) in the same area of the Apensu pit as the benchmarked material in January 2009. Top and bottom benches (or flitches) from each blast were sent exclusively to the grinding circuit and the material was tracked using PTI’s SmartTag™ system.The results from the six trials showed a significant increase in primary ore throughput at a reduced blend of oxide material. Ahafo have since standardised on these modified blasting conditions for all Apensu ore zones and have been able to sustain higher throughput compared to historical performance on similar material.This paper summarises the phases of the PIO project, the changes made in operating practices and the outcomes of the blasting trials that validated the predicted increase in mill throughput."

Jan 1, 2012

By Afshin Sadri, Wai Lai Ying, Brycklin Wilson, Zoe Coull

"Although there have been great steps forward to integrate corrosion engineering into operations, there is still an underlying tendency for maintenance tasks to be performed in a reactive manner. This is especially true when strategies focus on lagging indicators such as visual inspections, RCA (root-cause analysis), and FMECA (failure mode, effects and criticality analysis). This trend to “reactive maintenance” can be avoided by utilizing more inspection and monitoring methods to identify leading indicators of failures. Prevention is generally less costly than repairs; moreover, when paired with appropriate monitoring techniques, intervention of corrosion protection can be more effectively timed and based on more accurate data. Hatch asset reliability studies show nearly 80% of defects are introduced through operations and maintenance. Therefore, proactive corrosion management can provide the necessary feedback to optimize operations and maintenance strategies preventing costly corrosion losses. Understanding corrosion risks gives a clear picture of the benefits of a proactive approach to asset performance. Monitoring techniques (Non-Destructive Testing, field testing, sampling, etc.) by nature are a more effective means of improving maintenance efforts and preventing corrosion losses than other methods (RCA, FMECA). This paper will outline the importance of proactive corrosion management and demonstrate its benefits through industry examples.INTRODUCTION Over the past few decades, with the growth of technology and awareness of sustainable development many studies have shown the benefits of a proactive approach to maintenance strategies. However, in practice there is still an underlying tendency for maintenance tasks to be performed in a “reactive manner”. This is especially true when strategies focus on lagging indicators such as visual inspections, RCA (root-cause analysis), and FMECA (failure mode, effects and criticality analysis). This trend to “reactive maintenance” can be avoided by utilizing more inspection and monitoring methods to identify defects and leading indicators to failures."

Jan 1, 2017

By D. Nower

"The supply of copper is expected to be at a large deficit in 2012. To recover from these deficits mining companies are required to maximize production and there is no better way to accomplish this than to optimize the use of their mobile mining equipment fleets. To optimize these fleets, each equipment type has to be monitored in its own unique way. Automation would not only improve production, but also minimize the safety risks and eliminate planning errors. The automated vibration monitoring of multiple systems on the shovel can determine the machine’s condition at all times. This reduces unplanned downtime and keeps critical shovels in production. This paper will discuss the details of how shovels can be successfully monitored, continuously. INTRODUCTIONP&H Mining, part of Joy Global, is the world’s largest manufacturer of above-ground mining equipment. Its electric rope shovels, such as Figure 1, with capacities up to 115 tons (104.3 metric tons), are used for high production loading in surface mines; its draglines, such as Figure 2, have bucket capacities to 160 cubic yards (122 cubic meters). P&H also produces blasthole drills, mobile mining crushers and other essential mining equipment. Headquartered in Milwaukee, WI, the company does business on every continent, except Antarctica. ECONOMIC FACTORSDue to the global demands for metals and power, mines are required to operate at full capacity. Mine operations cannot afford any critical assets to shutdown unexpectedly; depending on the ore type and quality, downtime for a single shovel can be as much as $300,000 per hour.Electric rope shovels are one of the most critical assets in open pit mining. They are very large, complex machines with DC or AC motors, multiple reduction gearboxes (some of them complex planetary) and multiple large rolling element bearings. This complexity, combined with the tough 24/7 service, results in too much unplanned shovel downtime, which can affect the entire downstream process."

Jan 1, 2012

By W. D. Freeborn

Slim-hole drilling and completion techniques were first used in the Cynthia area of the Pembina field, Alberta, by the Texaco Exploration Company in the summer of 1957. Prior to that time, eighty-eight wells had been drilled and completed in this area in a conventional manner. Subsequent to the initial four-well evaluation programme, twenty-one additional wells have been drilled using slim-hole techniques. No difficulty was encountered in the drilling and completion of slim-hole wells, or in obtaining production from them. A comparison of drilling and completion economics and practices has been made for slim-hole and conventionally completed wells. Penetration rates for both bit sizes (614 in. and 9 in.) were relatively equal. The shorter life of the smaller bits required the use of 15 per cent more bits per well, but the total trip time to change bits was similar for both hole sizes because of the higher hoisting speeds possible with the lighter drilling strings used in the slim holes and better hole conditions. Completion costs of the slim holes were reduced by 37 per cent as compared to the costs of conventional-type completions. This was made possible through the use of smaller well equipment, the elimination of tubing, and a reduction in rig time for completion operations.

Jan 1, 1958

By B. Drew, K. Budna, C. Wenzl, D. Gregurek, A. Spanring

"The metallurgy of nickel and cobalt and of copper is closely interlinked when processing sulfidic Ni-Co ores and Cu-Co ores. The respective furnaces are typically lined with magnesia-chromite refractories, which are exposed to multiple and complex stresses. The selection of the processing route, furnace type and slag system will be dictated by the specific ore type available, this will determine the individual refractory wear mode. This paper evaluates the common refractory wear mechanisms, namely infiltration, spalling and chemical attack by various slag systems, as well as sulfur attack, as observed when processing primary sulfidic ores. All these wear parameters, which are discussed in this paper, lead to a severe degeneration of the brick microstructure and a decreased lining life. Therefore, a detailed investigation and understanding of the wear mechanisms through “post mortem studies” is an important prerequisite for the refractory producer. Based on such research results, combined with specific process knowledge, appropriate brick lining solutions for nickel and cobalt processing furnaces can be recommended.INTRODUCTION The metallurgical production of cobalt and nickel and of copper is closely interlinked to the mineralogy of the respective ores: cobalt is found in African Cu-Co ores as well as in Co-rich nickel ores (laterites and sulfides). Also, Co-bearing secondary raw materials contain the mentioned elements in different contents. In pyrometallurgical processing of sulfidic ores, cobalt is generally recovered as a by-product during the production of copper and nickel, whereas it is normally not recovered separately during the processing of nickel laterites but remains in the FeNi product. Besides various hydrometallurgical production routes, the pyrometallurgical processes involved comprise smelting (i.e., production of a Cu-Ni-Co-Fe matte in electric or flash furnaces), converting and refining (i.e. removal of Fe and S as well as other elements from matte by oxidation). The ongoing trend to use higher oxygen enrichment in process air enables higher intensity processes but also increases the oxidation potential in the vessel. Therefore, during smelting and especially during the oxidative treatment in converting and refining, some amounts of valuable metals are also transferred to the slag in their oxides form. A subsequent slag treatment is then applied for recovering valuable metals from the slag, namely allowing an economic material stream handling and minimizing metal losses. This is often done in a slag reduction furnace. Additionally, copper and nickel are very good collectors for precious metals and platinum group metals (PGMs) - therefore, depending on the content of these metals, an additional refining process is used to recover these valuable metals from the matte or metal phase (Elvers et al., 1997; Davenport et al., 2002; Crundwell et al., 2011)."

Jan 1, 2017

By Simon Houlding

"Part 1 (CIM Bulletin, August 1991) of this article identified the limitations of the traditional modelling methods and demonstrated the approximations and errors introduced by their application to complex mining situations. The objective of Part 2 is to describe the evolution of new, proven technology which eliminates these deficiencies and provides precise and practical alternatives. These promote the use of realistic geological and mining shapes and eliminate altogether the rectangular approximations of traditional methods. Limitations of the Traditional MethodsThe limitations of the traditional modelling method s (viz. simple block modelling, gridded modelling and their more recent variations) were discussed in detail in Part I . These methods are all based on the use of rectangular discretization to represent the boundaries and volumes of ore deposits and mining excavations. As a result they are unsuited to the representation of nonrectangular geological complexities such as folding, faulting and irregular surfaces . They are equally unsuited to the representation of realistic excavation limits, particularly in the case of underground mining.Recently these methods, with limited variations in technique, have been applied to increasingly more complex geological and mining situations. The resulting potentials for error and conflict within the modelling pro cess were demon strated in Part I . The effects can be summarized as follows:• volume and boundary approximations introduced by therepresentation of irregular three-dimensional boundaries andvolumes by rectangular modelling elements ; • geostatistical errors and conflicts caused by neglect of the relationships between grade estimates and the geometric/ spatial aspects of irregular volumes and associated observations (samples), including an inability to produce precise estimates with meaningful confidence limits;• a compounding of these effects by using rectangular element sizes other than the geostatistical optimum, and by using differentelement sizes within a model; and• general inefficiencies introduced throughout the modelling pro cess by the requirement to represent geology, grade distribution and excavation limits with a singular modelling method and model."

Jan 1, 1991

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 G. Molloy

The purpose of this paper is to demonstrate the value of applying continuous improvement, in particular 5S and standard work, in an underground environment. 5S and standard work are two aspects of Lean manufacturing that have been applied in many industries. At Vale Canada Limited, the focus is to first stabilize the process, commonly through the use of 5S, standard work and other continuous improvement techniques. In parallel with building an engaged workforce, these approaches aim to incrementally stabilize and improve a process. 5S is an employee-driven, systematic methodology to reduce waste in all its forms through attaining, maintaining, and improving workplace organization. Identified as a foundational part of any improvement process, 5S aims to remove wastes that impact on the overall efficiency of the area. Standard work is used to formulate a common approach to how tasks are carried out to ensure consistency. Standardization involves identifying, establishing, and following the best method. The aim is to eliminate the variation that can occur when there is not a pre-defined established standard. Demonstrating the value of 5S and standard work in an underground environment will be achieved by first understanding the overall concept of Operational Excellence and continuous improvement as practiced within our operations. The paper will then cover a real application of 5S and standard work within the underground environment at Thompson, Manitoba.

Aug 1, 2013

By S. M. Chentouf, M. Jahazi, N. Bombardier, T. Belhadj

The main limiting factor in the commercial expansion of superplastic forming (SPF) of thin sheet aluminum alloys is the extent of cavitation phenomenon that takes place during the processing. The severity of the cavitation process is mainly dependent on the uniformity of deformation (i.e. level of local thinning) during processing. In the present paper, correlations are made between thickness variations in several formed sheets and the characteristics of the cavities observed in the material. The 1.4 mm thick 5083 aluminum alloy sheets were hot pre-formed at around 450°C for 4 min and then air-cooled. Opto-digital and Scanning Electron Microscopy were used to examine the microstructure and analyse the cavities. Also, grain size measurements were carried out for different location in the SPF formed piece. The surface and volume fractions of the cavities were measured with the aid of metallography image processing (MIPTM) on as-polished samples prior to etching. The results are analyzed in terms of the influence of applied strain and microstructure conditions on the propensity to cavitation of the alloy.

Jan 1, 2015

By S. Xu, A. Ramesh, F El-dabbagh, Z. Fang, A. Sobhy, J. A. Kozinski

Waste remediation is a goal that will be driven forward by economic conditions. As the cost of waste disposal increases, new methods of waste reduction will become economically attractive, and will be implemented. It is difficult to imagine, however, a time when there will be no waste generation. For the foreseeable future, despite effective reduction practices, there will still be hundreds of millions of tons of waste that must be destroyed or controlled to protect the public health and the sanctity of the environment. To remain faithful to environmental covenants, the mineral and metallurgical industries will face these new challenges. This paper discusses novel waste remediation approaches and techniques focusing on hazardous wastes and thermal remediation. Aspects concerning technological and environmental importance are examined. Solutions for neutralization of environmentally hazardous compounds are proposed.

Jan 1, 2004

By Deborah McCombe

"and Bill Roscoe, Consulting Geologist and Principal with Scott Wilson Roscoe Postle AssociatesMineral property valuations are carried out for a variety of reasons, such as mergers and acquisitions, non-arm’s length transactions, initial public offerings of stocks, support of audited financial statements, fairness opinions, determination of vendor considerations, litigation, expropriation, income tax matters and insurance claims.The CIMVal Committee was formed in 1999 to review and advise on approaches to the valuation of mineral properties. CIMVal is a special committee of CIM formed on the recommendation of the Mining Standards Task Force of the Toronto Stock Exchange and the Ontario Securities Commission.After solicitation of views and consultation with various interested parties, the CIMVal Draft Standards and Guidelines for Valuation of Mineral Properties were released for comment in February 2002 and were finalized in February 2003. CIMVal’s objective was for the standards to be used by the mining industry in general and to be adopted by Canadian securities regulators and Canadian stock exchanges. To that end, the standards contain many of the definitions and concepts of National Instrument 43-101, Standards of Disclosure for Mineral Projects, which came into force in February 2001.The intent of the CIMVal Standards and Guidelines is that mineral property valuations be carried out by appropriately qualified individuals and that all relevant information be fully disclosed. It consists of two parts: standards, which are mandatory in the valuation of mineral properties, and guidelines, which elaborate on the standards and provide guidance and recommendations for the valuation process and for reporting."

Jan 1, 2003

By D. M. Maijer, S. M. Mohseni, A. B. Phillion

The microstructure evolution kinetics of aluminum alloy B206 during artificial aging has been investigated using non-isothermal calorimetry. A combination of differential-scanning calorimetry (DSC) and tensile tests have been utilized to develop an Avrami model to predict the precipitation kinetics as a function of the thermal processing parameters. The Avrami coefficients, found based on a Kissinger analysis, compare well against those reported in the literature for aluminum-copper alloys. The rapid precipitation kinetics predicted by the Avrami model at temperatures higher than 200°C were assessed through a qualitative comparison against hardness measurement results. In contrast to the continuous hardening observed at 150°C, the material softens with continuing heat treatment at 250°C resulting in an overaged state. This can be attributed to the rapid precipitation kinetics at this temperature, leading to the termination of the precipitation-hardening effects at early stages of artificial aging.

Jan 1, 2015

By Andrew Thrift

Overview ? Problem ? Research question ? Literature review ? Methodology ? Results ? Discussion and recommendations ? New developments Problem ? Increasingly higher expectations ? Inadequate consultation leads to conflict rather than collaboration ? Consultation practice is often weak on decision-making ? Influence of consultation on planning is Unclear Research question ? Are Structured Decision Processes (based on decision analysis) an effective methodology for involving stakeholders in consultative decisionmaking in the mining industry?

May 1, 2006

By K. Horikawa, S. Kitahata, H. Kobayashi

"It has been clarified that the Al-5%Mg alloys containing 200 mass ppm of sodium showed grain boundary (GB) fracture, even when tested at room temperature, as well as at high temperatures (~500°C). SEM/EDX study revealed that the GB fracture was associated with the segregation of sodium on grain boundaries of the Al-Mg base alloys. Differential scanning calorimetry (DSC) revealed that the GB fracture at room temperature of Al-Mg alloys was caused by sodium segregation in the solid state. It was also shown that the tendency of the GB fracture strongly depended on the heat treatment; the alloys after the solution heat treatment showed severe GB fracture compared with the alloys after the homogenizing treatment. Moreover, it was shown that the GB fracture at room temperature by sodium segregation was suppressed by the addition of bismuth or indium. The suppression of the GB fracture by the additional elements was believed to be the scavenging effects by forming the sodium bearing compounds in grains.INTRODUCTIONIt is widely known that Al-Mg base alloys containing high amount of magnesium(~5 mass%)show better workability at room temperature, while that the alloys show grain boundary (GB) embrittlement at higher temperatures ranging from 200 to 500°C, depending on grain size(Otsuka, 1984), sodium impurity level(Ransley, 1959, Okada, 1997, Horikawa, 2001)and testing strain rate(Yamada, 2012). In the case of coarse-grained Al-5%Mg alloys (~300 ?m), 2 mass ppm of sodium causes severe GB fracture around 300°C, however, the Al-5%Mg-2ppm alloy does not show GB fracture at room temperature. It has also been shown that the GB embrittlement caused by 2ppm of sodium was suppressed by the additional elements, such as bismuth (Talbot, 1995), antimony (Ueda, 1997) and indium (Horikawa, 2012). Basedon these facts, we have concluded that the GB embrittlement at higher temperatures of Al-Mg alloys is attributed to the synergy effects of GB segregation of atomic sodium and GB sliding. For the GB embrittlement mechanism of Al-Mg alloys, involvement of low melting point metallic phases has been pointed out (Lynch, 2002),since the GB embrittlement appeared only at high temperatures. Up to date, the effects of high amount of sodium addition more than 2 ppm on GB fracture were not fully investigated in Al-Mg alloys. In the present study, the effect of 100 ppm ordered sodium impurity on GB fracture of Al-5%Mg alloys was examined, together with the effect of another additional elements."

Jan 1, 2017

By Carlos Palacios M., Brian K. Townley

"Abstract - The mainland Aysén region of Chilean Patagonia (44°15' - 47°30'S) is a representative segment of the South American active continental margin, distinct with respect to northern and central Chile. Mineralization consists mainly of polymetallic deposits, with important Zn-Pb mines and more recently discovered Au-Ag deposits, unlike the central Andes, which are dominated by Cu mineralization. On a regional scale, rocks may be grouped in four main map units: 1) the Paleozoic metamorphic basement; 2) upper Jurassic-Cretaceous calc-alkaline volcanic and marine sedimentary rocks; 3) the Patagonian batholith, and 4) upper Cretaceous to Miocene basalts and marine and continental sedimentary rocks. The upper Jurassic-Cretaceous rocks and the Patagonian batholith formed in a volcanic arc and back-arc setting superimposed on the Paleozoic metamorphic basement.Based on geographic location and geologic and tectonic setting, ore deposits in this region are assigned to three groups, from south to north: El Faldeo, Fachinal, and El Toqui. The El Faldeo group (south of 47°05'S) includes upper Jurassic Zn-Pb skarn and associated polymetallic massive sulfide vein deposits locally overprinted by Au-rich epithermal mineralization, hosted by volcanic and sedimentary rocks and/or by rocks of the metamorphic basement. The Fachinal group (46°05' - 47°05'S) consists of volcanic-hosted lower Cretaceous Au-Ag epithermal deposits, except for the Mina Silva and Manto Rosillo deposits, which are metamorphic basement-hosted Zn-Pb skarns. The El Toqui group (44°30' - 46°05'S) comprises lower Cretaceous Au-rich Zn-Pb skarns and associated polymetallic veins, as well as Au-Ag-rich epithermal deposits, hosted by volcanic, intrusive, and marine sedimentary rocks. Galena lead isotopic signatures for each deposit group indicate a decreasingly radiogenic trend from south to north, suggesting different lead sources or differences among underlying crust. Three metallogenic provinces and two metallogenic epochs are proposed for the Aysén region: the El Faldeo metallogenic province of Late Jurassic age; and the Fachinal and El Toqui provinces of Early Cretaceous age. Résumé - La partie continentale de la région d’Aysen (Patagonie chilienne, 44°15' - 47°30'S), est unsegment représentatif de la marge continentale active d’Amérique du sud, différent des segments du nordet du centre du Chili. La minéralisation, qui consiste essentiellement en des dépôts polymétalliques, avec d’importantes mines de Pb-Zn, et des dépôts d’Au-Ag récemment découverts, différe de celle des Andes centrales où domine la minéralisation cuprifère. A l’échelle régionale, les roches peuvent être regroupées en quatre unités cartographiques principales : 1) le socle métamorphique paléozoïque, 2) les roches volcaniques calco-alcalines et les sédiments marins du Jurassique supérieur-Crétacé, 3) le batholite patagonien, et 4) les sédiments marins et continentaux ainsi que les basaltes du Crétacé supérieur-Miocène. Les roches du Jurassique supérieur-Crétacé et le batholite patagonien, formés dans un contexte d’arc volcanique et d’arrière-arc se superposent au socle métamorphique paléozoïque.Fondé sur la localisation géographique ainsi que sur le cadre tectonique et géologique, les dépôts de minerais de cette région se répartissent en trois groupes, du sud au nord, El Faldeo, Fachinal et El Toqui. Le Groupe El Faldeo (sud de 47°05'S) contient des skarns à Pb-Zn du Jurassique supérieur associés à des veines de sulfures massifs polymétalliques, localement recoupées par des minéralisations épithermales, riches en Au, et contenus dans des roches sédimentaires et volcaniques et/ou dans des roches du socle métamorphique. Le Groupe Fachinal (46°05' - 47°05'S) consiste en des dépôts épithermaux Au-Ag, se trouvant dans des roches volcaniques du Crétacé inférieur, excepté pour les dépôts de la Mine Silva et Manto Rosillo, où des skarns à Pb-Zn, se trouvent dans le socle métamorphique. Le Groupe El"

Jan 1, 1999

By F. Henríquez, V. Iriarte, L. Vinnett, J. Yianatos, F. Díaz

Metallurgical characterizations of the collective (Cu/Mo) and selective flotation plants were carried out in Minera Los Pelambres, Chile. The selective plant allows the valuable minerals of Cu and Mo to be separated. The evaluation involved two surveys consisting of metallurgical sampling as well as residence time distribution (RTD) measurements to determine load distribution. The RTD data were obtained in real-time by means of the radioactive tracer technique. In addition, metallurgical data was reconciled and supported by effective residence times. In the collective plant, a performance comparison of parallel rougher circuits was carried out, which included a bank of six mechanical cells of 250 m3 and banks of nine mechanical cells of 130 m3. In the selective plant, the Cu and Mo evolution along the plant was evaluated. The results in the selective plant allowed for performance evaluation of mechanical and pneumatic cells in primary flotation. In both plants, mineral losses were evaluated and their relationship with circuit configuration (cell types and circuit layout) was determined. The metallurgical characterization was a powerful tool to evaluate circuit performance and to detect improvement opportunities at industrial scale.

Jan 1, 2015

By R. L. Bruening, L. Navarro, R. M. Izatt, N. E. Izatt, S. R. Izatt

Green chemistry principles will be discussed, and examples will be given of the use of Molecular Recognition Technology (MRT) to selectively separate valuable metals such as rhenium and palladium from various copper refinery feed streams. Recovery of these metals has numerous advantages including (i) conservation of valuable resources, (ii) prevention of environmental damage, and (iii) elimination of capital and operating expenses due to re-processing or disposal of metal-bearing streams. INTRODUCTION Refining of copper ores has a long and successful story. The history of copper, one of the first metals mined in human history, illustrates the global challenges faced as a result of increased demand for major metals and for by-product specialty metals found with them in trace amounts (Izatt et al., 2014). Copper has valuable properties, which have sustained its use over the centuries. It is an ideal material for creation of novel materials. Some desirable properties of copper that have proved valuable in our high-technology society include suitability for alloying with many other metals; ease of joining by soldering and brazing; good combination of mechanical qualities; high resistance to corrosion; suitability for many artistic purposes; and, of great importance in the modern era, efficient and economic use as a conductor of electricity. Copper mining in the U.S.A. began in the late nineteenth century in Montana (Izatt et al., 2014). The estimated total amount of copper mined globally before 1800 is about 5 million tons, four times less than is mined in a single year today (Flanagan, 2018). Production of copper in the U.S.A. has remained fairly constant at about 1,300,000 to 1,400,000 metric tons per annum from 2013 to 2017. Specialty metals such as bismuth, rhenium, molybdenum, and others that have become essential in our 21st century technology, and precious metals such as silver, gold, and the platinum group metals (PGMs) are concentrated by geochemical processes in trace amounts in copper ores. These specialty and precious metals were discarded into tailings in early mining operations, since limited extractive technologies existed and uses for most of them were limited. Thus, economic benefits for recovering them were limited, primarily, to silver and gold. Today, copper processing is the main, and often the only, commercial source for certain of these elements (Izatt et al., 2014). For example, molybdenite (MoS2) is the predominant ore mineral of molybdenum mining (Pohl, 2011). Cu-Mo-Au porphyry ore deposits supply ~75% of the world’s copper, 50% of the molybdenum, nearly all of the rhenium, and 20% of the gold. Typical ore grades are 0.5–1.5% copper, 0.01–0.04% molybdenum, and <1.5 g/ton gold. Molybdenite is the primary source for rhenium, among the rarest of metals, which is an essential component of super alloys, such as turbine blades in the aerospace industry (Pohl, 2011). Most rhenium is obtained as a by-product of molybdenite from copper mines in Chile. The case of rhenium raises an important issue. Continued availability of rhenium, selectively concentrated in copper ores, depends on continued mining and processing of copper. Since the mining company’s main interest is typically in copper production, continued recovery of rhenium and other specialty elements present in the ore body is at risk. Dependence of specialty metal supply on continued mining of major metals exists in several additional cases including indium, gallium, selenium, tellurium, germanium and bismuth (Pohl, 2011). PGMs, on the other hand, are typically mined for their own value, which far exceeds that of associated base metals. However, copper ores often contain marketable amounts of platinum and palladium, making their separation of interest, if this can be done economically.

Jan 1, 2019