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By L. C. Hsu, M. O. Desilets, P. J. Lechler, Jr. Bonham, J. G. Price, L. J. Garside

Geochemical background levels have been established for unmineralized sedimentary rocks that are elsewhere the hosts of Carlin-type gold deposits in the Getchell Trend. The Paleozoic rocks in the Winnemucca Quadrangle consist predominantly of the lower Paleozoicsiliceous and clastic sequences that were carried eastward along the Roberts Mountains thrust during the Late Devonian and Early Mississippian Antler Orogeny and the late Paleozoic Havallah and Pumpernickel sequences brought along the Golconda thrust eastward during early Mesozoic Sonoma Orogeny. Over 260 rock samples were collected from the Paleozoic sequences. Major and trace elements were determined by instrumental methods best suited for the specific elements. The general geochemical features of the Paleozoic sedimentary rocks are discussed in detail with reference to the data of average abundances of elements in sedimentary rocks. The background and threshold values of certain trace elements in sandstone, shale, and carbonate rock of one formation, as well as back-ground levels for the entire sequence were obtained. The characteristic geochemical features of the Paleozoic rocks in this area include: consistently high Ba and low Au contents (1.1 ppb, 1.5 ppb, 1.1ppb Au for average sandstone, shale and carbonate, respectively); generally low contents of those elements which may be of environmental concern such as As, Cd, Hg and Pb. Plots of major and trace elements suggest that the majority of the Paleozoic clastic rocks are related to a passive-margin tectonic setting. Samples with gold values higher than threshold are considered to have been affected by hydrothermal alteration related to gold mineralization. Most of these samples generally also have higher values of Sb, Hg, V and/or As. These observations support the use of such elements as pathfinders for gold, although V has not been identified as such before. Ba is not effective for gold exploration in this area due to the generally high background value of Ba, even though it may be an important pathfinder elsewhere.

Jan 1, 1995

By Pierre Gaucher

It is possible to selectively mine an orebody by combining the use of the SSW probe with any bulk mining methods as well as narrow vein exploitations. In other words, thanks to the use of the SSW probe, mining operators will be able to reduce and control dilution that is generally associated to every mining operation. Already, quick and substantial savings have been obtained. Falconbridge mines have demonstrated in Sudbury and Raglan operations, that the SSW probe can log nickel, copper and iron sulphides in blast holes. They have raised the grade and reduced dilution by outlining the limits of the ore zones before selectively loading explosives in the blast holes. By lowering the probe in a blast hole, a profile of the ore content is instantly measured and recorded. Logging cored diamond drill holes at the mine have demonstrated that the ore content (nickel, copper, cobalt, PGM) as assayed is proportional to the intensity of the probe?s electromagnetic response (EM), probably because the nickel / pyrrhotite ratio is uniform within a given orebody. The probe also measures the intrinsic conductivity of the sulphides and the percentage of magnetite. All probe readings are displayed and automatically stored at a 10-cm interval within the same reading unit. A 30-meter blast hole takes less than 2 minutes to survey. The whole instrument is light (12 kg) and very simple to use. One operator can carry the SSW system and survey either down or up-holes. The probe works from ?40°C to +50°C. Plotting the measurements of the SSW probe in blast holes (2-3-4-6-10 inches in diameter) before blasting allows to determine the exact shape of the orebody within the waste rock and uneconomic low-grade ore. Thus, only the portion of the holes that contains ore is blasted. The dilution is then much reduced and, by leaving the waste and low-grade ore in place, the mine saves on transportation, blasting, crushing, backfilling, milling, etc. Thousands of dollars are thus saved. Some savings may also be achieved during the development of stopes by guiding development drifts and by replacing diamond drilling by percussion drilling. In some circumstances, when the probe shows that some of the rich ore was not drilled-off, additional blast holes will allow to recover pockets of rich ore that otherwise would have been abandoned in the walls of a stope.

May 1, 2001

By I. Paredes, R. Díaz, H. Henao

Smelting of copper concentrate generates a significant amount of dusts which are collected in electrostatic precipitators. This material, which is a complex oxide of Cu, Fe, S, As, Sb, Bi and others, is difficult to recirculate into the smelting process due to the reported high concentration of arsenic. However, the dust also has concentration of copper above 10wt %, aside from reported contents of silver corresponding as much as 25wt% of the total inventories of this element in the smelters. Thus, it is of economic and environmental interest the development of a process able to reduce the concentration of arsenic in the dust and produce a material suitable to be recirculated into the smelting process. The present experimental work shows the results of a process of dust sulfidization-oxidition able to remove more than 65wt% of the arsenic present. INTRODUCTION Copper sulfide deposits worldwide exhibit increasing concentrations of arsenic. One case of interest would be the copper ores from the northern zone of Chile, which report high concentrations of enargite (Cu3AsS4) (Revista química, 2015) (Latinominería, 2014). The obtained concentrate from this ore is treated in a Fluidized Bed Roaster, producing calcines with low concentration of arsenic (<0.5 wt% As). This material is suitable to be treated in a Flash Furnace. At the roasting process, the arsenic is volatilized and then precipitated as fine particles of complex oxides. Most of this particulate material is removed from the gas stream through a device called Electrostatic Precipitator (Minería chilena, 2014). The experimental results reported in the literature indicate that arsenic present in these particulate materials (or dusts) cannot be eliminated in oxidizing atmospheres (air) or with inert gases (N2) in a Fluidized Bed Roaster even at temperatures as high as 700°C. There is also information that even the recovery of valuable metals from the dust is difficult through hydrometallurgical processes (private communication). This is how in some foundries these dusts are considered environmental liabilities. Regarding the decomposition of enargite (Cu3AsS4) in neutral atmosphere, it is reported in the literature (Padilla, 2001) that the main chemical reactions are:

Jan 1, 2019

By Yongteng Dong, John P. Quinn, Bradford Wesstrom, Guikuan Yue

With increasingly low-grade copper ores being mined, it is difficult to handle growing concentrations of As, Sb, Bi and/or Fe in the whole flowsheet, especially during copper electrorefining. To better elucidate the effects of those impurities on the quality of cathode deposit and/or current efficiency, a detailed speciation study of the electrolyte under industrial conditions is required to quantitatively describe their distribution in the solution, thereby facilitating their effective control and removal. In the present study, a thermodynamic model of complicated iron-arsenic-copper-sulfuric acid electrolyte under industrial conditions was developed. The main species of those elements involved in the electrolyte were first identified, and their thermodynamic data were collected and critically assessed. Those data were then used to estimate the activity coefficients of species, and to calculate the equilibrium constants from 25°C to 70°C. The developed model provides a mathematical tool that is capable of quantifying the concentrations of free ions and complexes in terms of temperature and solution composition. Finally, oxidation-reduction potential measurements were employed to validate the model. INTRODUCTION In copper electrorefining, impurities like arsenic, antimony, bismuth and/or iron can partially dissolve in the electrolyte and accumulate gradually, and eventually cause problems such as bad cathode deposit (co-deposition with copper or mechanical inclusion from the floating slime), lower current efficiency, etc., which eventually increases the operating costs. The presence of impurities may substantially reduce properties of copper products such as conductivity, corrosion resistance, mechanical properties, and leads to more energy consumption (Schlesinger et al., 2011; Jafari et al., 2017). To remove these impurities, various methods have already been proposed and applied in industrial copper production, such as solvent extraction, ion exchange, chemical precipitation, absorption by activated carbon, etc. (Cunningham et al., 1997; Navarro et al., 1999; Toyabe et al., 1987). In addition, adding reducing agents such as sulfur dioxide and trivalent arsenic could also precipitate arsenic, antimony and bismuth from copper electrolyte, by changing the distribution of impurities with various valence (Braun et al., 1976; Xiao et al., 2007). The disadvantages of those methods include high energy consumption, serious contamination, lower selectivity and efficiency, and so on.

Jan 1, 2019

By Laxman M. Amaratunga, Glen G. Hein

"Most mining operations utilize the tailings coarse fraction for backfilling while the fines have been traditionally disposed on surface in tailings ponds. Recently, paste fill has been developed which uses a fraction of the fine tailings (10-30% w/w of <45 µm) in the fill (Brummer and Moss, 1991). This development allows a mining company to use a portion of the fines for backfill, but still requires surface impoundment of the unused tailings. Reactive tailings have the added problem of generating acid after being oxidized in the presence of air and water. Treating acid mine drainage (AMO) from these ponds has proven to be a costly environmental problem and a long term liability.One practical method to reduce the environmental impacts associated with the tailings pond is to modify the physical and chemical prope1ties of the fine tailings so that they can be utilized in an environmentally safe manner. This was accomplished by agglomerating the tailings into pellets and using theses pellets as a coarse aggregate in a total tailings paste fill. This technology does not require any supplemental sand or gravel to be added to the fill.This paper presents the ongoing research into utilizing these tailings agglomerates as a coarse aggregate fraction, in order to create a total tailings paste fill which has supe1ior strength characteristics.IntroductionThe Canadian mining industry produces more than 500 million tonnes of tailings and waste rock annually. The waste rock is usually returned underground for use as rock fill in underground support with the tailings remaining to be disposed of in tailings ponds. Tailings consist of a coarse and fine fraction, and can be either reactive (acid generating) or non-reactive. In an effort to minimize tailings disposal, the coarse fraction has been used underground in backfill along with alluvial sands. This diversion of the coarse fraction, however still requires that the fine fraction be disposed of in tailings ponds. This disposal creates the potential for acid mine drainage (AMO), since in the presence of air and water, reactive sulphide tailings can generate acid. It is therefore an important goal in the mining industry to minimize the disposal of fine tailings into tailings ponds since the treatment of AMO is a costly and long-te1m environmental liability."

Jan 1, 1997

By R. A. Parra, Fuentes, C. Godoy, L. E. Arias, C. A. Toro, M. Marin, E. Balladares, V. Parra, G. Reyes, S. N. Torres, D. Sbarbaro

In this paper, we report on the detection of spectral molecular emission of iron oxide (FeO) and copper oxide (CuxO) emitted by reactions occurring in a laboratory scale flash smelting process of pyrite (FeS2) as well as copper concentrate. The novelty of the technique is that, the molecular spectral emission sensing is achieved by using a low spectral resolution and low sensitive radiometer, enhanced with signal processing and matrix factorization techniques. The method was validated using a highly sensitive spectrometer, with a high spectral resolution; achieving a similar FeO spectral pattern as the one obtained after signal processing techniques over low resolution spectral signals. INTRODUCTION Visible-near infrared (VIS-NIR) spectroscopy is an optical contactless sensing technique commonly used to capture information about the emitted, absorbed, transmitted or scattered radiation in a physical or chemical process, with the presence or absence of an excitation light source such as a laser or a broad spectral band source. These techniques coupled with signal processing and machine learning algorithms, sometimes referred as chemometrics (Pisapia et al., 2018), can be found in processes such as: pharmaceutical (Kandpal et al., 2016); food (Coelho et al., 2016); combustion (Ballester & García-Armingol, 2010); siderurgy (Strakowski et al., 2014) industry, among others. In the extractive copper industry there are several technological developments using optical sensing techniques aimed to retrieve information about copper ore and concentrate mineralogical composition such as X-Ray Fluorescence, Qemscan® (Quantitative Evaluation of Minerals by Scanning Electron Microscopy) and X Ray Diffraction (XRD) analysis, however, because of the manual procedures to analyze the samples with these laboratory instrumentation, only discrete information during a daily based operation can be retrieved, making impossible for the operators to take decisions over the involved processes in real time. The aim of our research work presented here is to contribute with sensing and data analysis procedures based on VIS-NIR spectroscopy for the flash smelting process characterization, particularly in this paper, with the detection of FeO and CuxO molecular emissions in a laboratory scale setup.

Jan 1, 2019

By Richard P. Taylor, Rod Henham

Abstract - Newly discovered pegmatites distributed throughout the sub-surface environs of the Musselwhite Archean gold deposit occur as narrow dikes that intrude most of the major lithological units. The mineralogy and textures of the pegmatite dikes are characteristic of granitic pegmatites of the "Rare-Element Class"; more specifically, they closely resemble varieties of the "Complex-type" granitic pegmatites that are commonly associated with zones of tantalum mineralization. The essential minerals in the dikes comprise albite, quartz, and K-feldspar, together with lesser amounts of mica (including lepidolite), spessartine, tourmaline, and locally, spodumene. Fine-grained (30 µm to 300 µm), tantalum-bearing minerals occur in the quartzo-feldspathic matrix of the dikes as disseminations, in interstices, and in small vugs. The nature of the tantalum-bearing mineral assemblage present in individual pegmatite dikes varies from a simple mineral assemblage composed of ferrocolumbite (with around 39 wt% Ta2O5) in the most northerly dike, to more complex assemblages comprised of manganotantalite (with up to 75 wt% Ta2O5), ferrotapiolite (with up to 79 wt% Ta2O5), and microlite (with up to 76 wt% Ta2O5) that are present in dikes located several kilometers to the south and southwest. The compositional characteristics and textural relationships of the tantalum-bearing minerals in the dikes provide evidence of igneous fractionation trends that are typical of rare-element granitic pegmatites. Such trends suggest that the newly discovered pegmatites represent part of a more extensive group of cogenetic, tantalum-mineralized dikes.

Jan 1, 2001

By A. Ghahreman

Activated carbon is proven to be able to catalyze arsenic oxidation in aqueous solution under acidic conditions. A commercially available granular coconut shell based activated carbon (AC) has been evaluated for catalysis of arsenic oxidation in this study. The rapid small-scale column test (RSSCT) has been developed to simulate and predict the performance of a carbon-based arsenic treatment system in a pilot scale reactor. Effects of residence time, aeration rate, and initial arsenic concentration in the influent solution on the AC catalysis of arsenic oxidation under dynamic and continuous conditions were studied by manipulating these parameters during RSSCTs. The effectiveness of the AC on arsenic oxidation was examined over the course of constant diffusivity based RSSCT operation. Residence time and initial arsenite concentration are proven to be the most effective impacting parameters on the arsenic oxidation process. For the 218 min residence time, the highest steady-state arsenic oxidation efficiency achieved was 98% with 1 g/L As(III) being treated at pH=1 under 0.05 L/min oxygen aeration. In a long-running RSSCT, the oxidation efficiency did not seem to deteriorate over a course of 666 hours operation, corresponding to 13986 mL total influent throughput volume. INTRODUCTION Arsenic is toxic to both animals and plants and inorganic arsenicals are proven carcinogens in humans. The increased extraction of low grade and complex mineral resources has introduced high ratios of arsenic into metallurgical processes. Discharge of arsenic by acid mine drainage resulting from mining activities has added intensive pressure on the need for proper treatment (Lawrence & Higgs, 1999). Since trivalent arsenite is more toxic and has lower affinity to solid surfaces for adsorption, many treatment systems initiate with an oxidation step to convert arsenite to arsenate and reach the ultimate immobilization of arsenic by the following precipitation of arsenate (Nazari, Radzinski, & Ghahreman, 2016). Scorodite precipitation has been studied extensively as a means of arsenic immobilization due to its high stability and negligible potential of releasing arsenic (Filippou & Demopoulos, 1997). As a stable ferric arsenate mineral, crystalline scorodite can contain up to 30 wt% arsenic (Paktunc, Dutrizac, & Gertsman, 2008). Arsenic must be in its pentavalent oxidation state in order for scorodite to be precipitated via oxidizing ferrous ions (Clancy, Hayes, & Raskin, 2013).

Jan 1, 2019

By Marko Lampi, Ross Andrews, Jouni Pihlasalo, Robert Matusewicz

With widespread discussion on reducing carbon, sulphur and other emissions, use of sustainable energy sources and the pivotal circular economy theme, consideration needs to be given to pyrometallurgical operations broadly and more specifically, non-ferrous metallurgy. These themes present a number of challenges in terms of current operations and the view of processing the metals which are largely taken for granted in day to day living. This paper considers how these themes will impact pyrometallurgical flowsheets using the non-ferrous base metals as an example. It will examine the flowsheet chain to offer views on the boundaries of flowsheet optimization and the application of available tools to meet these future goals and challenges. INTRODUCTION The themes of reducing footprint through lowered CO2, S and other emissions, together with process sustainability (e.g. lowered energy) and links to the circular economy are well known to everyone in the metals industries. Whether it is reducing greenhouse gas emissions or analysing the importance of metals recycling in the circular economy, all these themes carry with them the fundamental premise of any change being considered; how can you best optimize a system to meet your aims? Of course, this depends on the available tools and the approach used for optimisation.

Jan 1, 2019

By D. Naden, D. J. King

"The high capital and operating cost of liquid-solid separation circuits in hydrometallurgical plants has led to an increased focus on the use of in-pulp systems for metals recovery in order to eliminate the need for solids washing and to reduce the need for liquid-solid separation.Carbon-in-pulp (CIP) has now been accepted in Canada and around the world as the leading process for recovery of gold and silver, replacing the Merrill-Crowe process and thus removing the need for CCD thickeners or belt and drum filters. The overall design of conventional CIP adsorption circuits was established in the late 1970s and it has remained substantially unchanged until now. Most of the development work since 'hen has been concentrated on improving methods of separating pulp and carbon and on reducing carbon losses during transportation and agitation.Resin-in-pulp (RIP) has been used for many years in uranium mills in the USA. However, most of the plants were built in the 1960°s and RIP was only chosen when liquid-solid separation of leach pulps proved very difficult. The plants are far from ideal as they have high resin losses and high maintenance costs. Consequently, there is room for improvement.Davy McKee has taken a fresh look at the engineering development of in-pulp contactors leading to a fundamental redesign of the adsorption units. The improved in-pulp technology uses a modification of the proven air-swept screen techno1ogy together with a new technique of process operation. The new contactor operates at high pulp throughput rates with high concentrations of carbon or resin in the recovery stages, resulting in a significant reduction in the contactor size over conventional design. As a result of this reduction in the size of the contactor by up to 80%, significant savings can be made in equipment and building costs. In addition, the plant 1s easier to operate than a conventional CIP plant."

Jan 1, 1987

By K. P. Plucknett, Z. Memarrashidi

WC-Co ‘hard metals’ are widely used in a variety of industrial applications due to their resistance to abrasive wear, in addition to their high hardness and toughness. However, in contrast to their mechanical properties, the corrosion response of these materials is relatively poor. In the current work the corrosion mechanisms of two WC-Co cermets are analysed, with 10 and 30 vol. % of the Co metal binder, in a 3.5 wt.% NaCl aqueous solution. The assessment of corrosion involved a variety of electrochemical measurements, including open circuit potential, potentiodynamic polarisation and cyclic polarisation, together with systematic analysis of the post-corrosion solution chemistries using inductively coupled plasma optical emission spectroscopy. The corrosion potential and current density were determined, following Tafel extrapolation, allowing the calculation of the corrosion rates. It is demonstrated that continuous dissolution of the cobalt phase occurs during corrosion, which is a result of poor cermet passivation behaviour, and this response increases with the amount of binder in the cermet.

Jan 1, 2015

By Donald S. Cameron

By dispersing gold in high surface area form supported on metal oxides, its inert character can be transformed to make economical, effective catalysts. Gold has already been demonstrated in a number of fuel cell applications such as gas phase catalysts, electro-catalysts, and electrical connectors. In this paper, the various types of fuel cell systems are reviewed, and several opportunities for gold identified. Low temperature fuel cells, including alkaline and solid polymer electrolyte types rely on high surface area platinum group metal catalysts which are highly susceptible to poisoning by low concentrations of carbon monoxide in the fuel supply. Hydrogen is frequently obtained by steam reforming hydrocarbons, followed by the water gas shift (WGS) reaction. A promising initial use for supported gold catalysts is in catalysing this WGS reaction. Research has shown that gold supported on iron oxide (Au/a-Fe2O3 ) WGS catalysts are more active than the current commercial copper oxide / zinc oxide catalysts, and effective at temperatures as low as 120oC. Products from reformer/ water gas shift reactors can be further purified by removing traces of carbon monoxide. If a small proportion of oxygen is introduced into the fuel gas stream, carbon monoxide can be preferentially oxidized to carbon dioxide even in the presence of hydrogen. Gold nanoparticle catalysts on iron oxide support (Au/a-Fe2O3 ) have exhibited higher activity than commercially available platinum on alumina (Pt/?- Al2O3 ) preferential oxidation catalysts. The low temperature of this reaction may make it feasible to incorporate these catalysts within the fuel cell itself. Proton exchange fuel cells provide several possible applications for catalytically active gold and its alloys. Carbon supported platinum group metals would benefit greatly from improved electrical conductivity if gold replaced some or all of the carbon support material. As electrode current densities are raised, electrical resistance constitutes an increasing proportion of voltage losses within the fuel cell. Dramatic reductions in cell stack voltage losses have already been demonstrated by reducing inter-cell contact resistance using gold plating. The low temperature oxidation properties of gold catalysts have been investigated in controlling gaseous emissions from direct methanol fuel cells, and gold also provides essential catalysis in building direct borohydride oxidation fuel cells. The prospect of a range of other applications for gold in fuel cells to contribute useful improvements in corrosion resistance and conductivity is assessed. Globally, fuel cells have been developed for a wide range of applications including stationary generators, cars and buses, industrial vehicles and small portable power supplies, each of which represents a substantial market. Hence there are likely to be many and varied opportunities for gold catalysts to contribute to the performance and economics of the systems being commercialized.

Oct 1, 2003

By J. D. Templeton

A petroleum well that is not in use because it has ceased to produce oil/gas economically and dry holes are referred to as abandoned wells. Once a well is abandoned it is plugged with cement and can take anywhere from two days up to a week to cure depending on the number of plugs in the well. Since plugging a well costs capital, most wells are abandoned at the lowest possible cost and with the minimum obligations set by regulation agencies. These wells can present an enduring liability to petroleum companies. However, the depth and abundance of abandoned petroleum wells makes them an economically attractive source of geothermal energy. Geothermal energy harvested from an oil/gas well is a renewable energy source as long as it is extracted in a sustainable manner. The energy can be used to generate electricity, used directly for heating, incorporated into a water desalination process, or used by a heat pump for heating/cooling applications. In this paper we examine the possibility of extracting geothermal energy from abandoned oil/gas wells by studying the heat transfer in underground geothermal heat exchangers installed in these wells. The design configurations for the geothermal heat exchangers embedded inside a petroleum borehole can be a u-tube design or a shell and tube design (i.e. double pipe). Using in-situ gathered information from some representative petroleum boreholes, the effects of key parameters such as geothermal gradient, ground temperature values, and the flow inside of the tubes are evaluated. In order to provide a constant power production the inlet temperature can be adjusted to keep the difference between outlet and inlet temperatures equivalent. Higher differences between inflow and outflow temperatures will result in a less sustainable load put on the in-situ geothermal energy. Adding insulation to certain sections of the designs can minimize the transfer of thermal energy from the fluid to the surroundings. Insulation can also limit the thermal loss between the inflow and outflow tubes in the shell and tube design. Minimizing the energy loss of these designs leads to an increase in the outlet temperature, meaning a higher grade of heat. The sustainability of long term geothermal heat extraction is a balance between the rate at which geothermal energy is extracted and the rate at which the ground formation can replace this heat. Higher outlet temperatures can lead to a larger amount of power generation, and a higher coefficient of performance for heat pump applications.

Aug 1, 2013

By M. Remillard, M. Garon, M. Thérien, D. Hodouin

"Nineteen streams in the copper and zinc flotation units of the concentrator of the Matagami division of Noranda Inc. have been sampled for particle size distributions chemical assays, and gold and silver contents in each particle size interval. The data are upgraded by the mass balance package BILMAT. These results, in conjunction with microprobe analyses, are used to quantify the silver losses in the copper clean¬ing flotation stages and to determine how overall silver and three silver-bearing minerals are recovered in the plant final products.RESUME Dix-neuf produits des circuits de flottation du cuivre et du zinc de la division Matagami de Noranda Inc. ont été échantillonnés pour leur distribution granulométrique, analyses chimiques et le contenu d'argent et d'or des fractions granulométriques. Le bilan métallurgique a été obtenu à l'aide du programme BILMAT. Ces résultats couples avec une etude minéralogique à la microsonde sont utilises pour quantifier les pertes argentifères aux diverses étapes de nettoyage du circuit de cuivre et pour de¬terminer la repartition de l'argent et des trois minéraux argentifères dans les produitsfinals de l'usine.INTRODUCTION The Matagami division of NORANDA INC. produces copper and zinc concentrates from a sulphide ore which contains a small amount of gold (0.34 g/t) and silver (20 g/t). Only a small part of the silver (~-30%) is presently recovered in the copper concentrate. The objective of this study is to evaluate the metallurgical behaviour of silver, and secondarily of gold, in the flotation circuit for a possible increase of its recovery in the copper concentrate to improve its economic value. For that purpose it is worthwhile to study the minerals which bear silver and to determine the critical flotation stages where they are lost in the tails. The methodology proposed here is based on a coupling of a mineralogical study and a detailed mass balance calculation in the flotation circuit."

Jan 1, 1986

By K. Parameswaran

This paper builds on presentations made at the Conference of Metallurgists (COM) 2015, COM 2017 and Extraction 2018 and associated papers published in the respective conference proceedings. Based on the classic Brundtland Commission definition of sustainable development as “development that meets the needs of the present without compromising the ability of future generations to meet their own needs,” the paper describes how metal mining can be compatible with sustainable development and how sustainability considerations have been applied in the primary copper industry, using several examples of sustainable mining practices from ASARCO LLC operations. Finally, the paper discusses how these considerations might be used in the future by discussing the need for developing a sustainable development strategy and how this strategy can be aligned with the United Nations Sustainable Development Goals. INTRODUCTION The primary copper industry comprises: mining (also referred to as “extraction”); mineral processing (also referred to as “beneficiation, “milling” or “concentration,”) which includes leaching, solvent extraction (SX), crushing, grinding, froth and flotation operations; and metallurgical processing which includes smelting and converting; refining, which includes fire-refining or anode refining and electro-refining; and electrowinning (EW). There are two routes for producing refined copper: hydrometallurgical and pyrometallurgical. The hydrometallurgical route comprises mining (open-pit and underground), mineral processing (crushing and grinding — for heap leaching only; leaching and SX) and metallurgical processing (EW). The pyrometallurgical route involves mining, mineral processing (crushing, grinding and froth flotation) and metallurgical processing (smelting, fire refining and electro- refining). The primary copper industry is capital, water, resource and energy intensive with the potential for significant environmental impacts, if the environmental aspects are not properly managed. ASARCO LLC (Asarco) was organized in 1899 as the American Smelting And Refining Company. Originally a consolidation of several lead-silver smelting companies, it evolved over the years into an integrated producer of primary non-ferrous metals, including copper, lead and zinc and associated co-products. Grupo México, S.A.B. de C.V (Grupo México) acquired Asarco in 1999. Today, Asarco is a vertically integrated producer of primary refined copper and associated co-products such as gold, silver, selenium and tellurium. Asarco operates three open-pit mines and mills, two leach, SX-EW plants, a copper smelter in Arizona and a copper electrolytic refinery in Texas.

Jan 1, 2019

By Robert Cameron, Colin Ashton, John MacNeil, Leo Piciacchia

"The in pit dam construction and utilities relocation, known as the East Mine Corridor Relocation (EMCR) project, was developed to extend the life of the east side of the Base Mine pit by two veal&apos;s. This will result in the recovery of an additional 80 million barrels of oil and delay expenditures associated with the opening of the North Mine by two years. To accomplish this, a large in pit earth structure was required to provide a new embankment foundation for relocating a public highway, four powerlines, a natural gas back-up pipeline, a substation, and a conveyor train. This structure would also he required as a temporary dam 10 contain mature fine tails on the west side until mining is completed in the east mine corridor area, that will then be filled with fluid.The in pit dam, known as The Highway Berm, is 2.5 km long, 63 m high and has 42 million m3 of engineered soil added to the already existing end-dumped soil volumes. To complete the design and construction of a structure of this magnitude, in the very short time frame of two-and-a-half years, presented many new challenges. The main challenges faced were: designing while construction was ongoing; designing without the use of clay cores or sand filters; using relatively non-select overburden material; proper dewatering and base preparation; changing from construction of 50 m high spoil piles to a high specification construction operation; compacting lifts with heavy haulers; constructing during the winter; and monitoring movement of the structure with satellites."

Jan 1, 1995

By R. Bridge

Mining companies are progressively finding themselves having to develop operations for more complex, deeper ore bodies, which require the use of more complicated mining and mineral processing methods. This coupled with the generally increasing trend of higher capital and operational costs have led to a need in the industry for improving ore body knowledge, mining and mineral processing. Geometallurgy is a relatively new concept that can link the three aspects, and when used effectively it is a method that can produce the necessary information for designing and building operations for reliable and optimum performance. Geometallurgy not only involves the integration of geological, mining, and metallurgical fields, but it can also be expanded to include environmental and economic information to produce a block model that can be used to obtain the best outcome in terms of plant response and plant sustainability. The geometallurgical program should not end once the block model has been populated. A detailed geometallurgical approach should be applied to all stages of the operation encompassing sample selection, through to equipment sizing and production forecasting. It can also become a useful optimisation tool thereby allowing the operation to be proactive rather than reactive against changes in the ore characteristics. With the development of metallurgical performance predictors it is possible to quantify how the ore will behave in the process plant in terms of throughput, recoveries, reagent consumption, etc. Therefore, in terms of responsible mining and sustainable resource development, a geometallurgical approach to operations is the logical step for plant development. In this paper we describe the state of the technology with respect to the application of geometallurgical modeling and its utilisation in the fields of design, forecasting and optimisation of mining operations.

Aug 1, 2013

By R. H. Coloquhoun

"INTRODUCTIONDome Mines Limited is located on 3,149 acres in Tisdale, Whitney and Shaw Townships in the City of Timmins in Northern Ontario. The mine and mill facilities are two miles from the town of South Porcupine, now part of greater Timmins.In April of 1909, J.S. Wilson of Massey, Ontario headed a party of prospectors into the Porcupine region. Disembarking from the Temiskaming and Northern Ontario Railway at mileage 222, they established an initial camp on the shore of Frederick House Lake. Following the lake ""break up"" they canoed to their destination, Porcupine Lake, and established a base camp on the west side of the lake by May 23, 1909. At a point approximately two miles from Porcupine Lake the moss on an outcrop was rolled back and gold was discovered.In the spring of 1911, the first mill structure was in the process of being built and consisted of 40 stamp mills, five S'x22' pebble mills and the ancillary equipment for a 300-400 T.P.O. operation. This structure was destroyed along with much of the Porcupine Camp by the famous Porcupine Fire of July 1911. By mid-1912, a steel ""fire proof"" structure was built and utilizing the salvaged mills from the fire, supplemented by the installation of three, 8'x30"" cylindro-conical Hardinge ball mills purchased third hand from Vipond Mines, processed 75,088 tons by year's end.The mill was again levelled by fire in October of 1929, this time caused by an overheated boiler stack. This 11 fire proof"" structure was immediately replaced by a wood structure and again the three Hardinge conical mills and the five 5'x22' pebble mills were restored and utilized. The new mill operated close to its daily capacity of 1500 tons during the last two months of 1930. During the rebuilding phase, the crushing plant was remodelled and a new crusher installed. These plants were protected from fire by a 60,000 gallon water tank and an automatic sprinkler system."

Jan 1, 1984

By A. Probst, N. Moores, J. A. Finch

"In 1994 McGill and INCO (Sudbury operation) initiated transfer of technology originally developed to detect level in flotation columns to thickeners. A conductivity probe was installed in a concentrate thickener to monitor the mud-line and solids load. The probe consisted in a vertical tube with 32 equally-spaced electrode rings connected in pairs to give 31 conductivity cells. Conductivity was measured as a function of depth (so-called conductivity profile) from which the mud line and % solids could be inferred. The probe was installed in October 1994 and has been successfully detecting profiles since then. This communication includes a description of incidents and experiences during this technology transfer process including: probe installation and start-up; software modifications to accommodate operating conditions and operators' needs; calibration procedures to adjust to changes in performance as a consequence of long term use; and preliminary observations on the last stage, still in progress, signal interpretation and use to facilitate operation, particularly by providing early reaction to upstream disturbances.IntroductionThickening is one of the basic unit operations in mineral processing and hydrometallurgy used to separate suspended solid particles from a solid-liquid dispersion by gravity settling. As the dispersion enters the thickener, the solids settle and clarified water overflows the top. A thickener, which may be continuous or batch, is basically a large vertical cylindrical tank provided with devices to feed the dispersion and to remove the settled solids. The tank provides residence time for the particles to settle. The dispersion enters the thickener through the feedwell whose function is to dissipate the momentum of the feed stream and to create relatively quiescent conditions around the entering point. Rotating rake arms move the settled solids towards the discharge point located at the bottom centre of the tank.There are normally three distinct zones in a thickener: a top layer of clear water, a middle layer called a sedimenting zone in which particles are settling, and a bottom layer called a compression zone in which particles are pressed together as a consequence of the weight of accumulated particles. Proper operation of a thickener requires two simultaneous conditions: no solids in the water overflowing the top and the target solids content in the underflow pulp. To achieve these conditions is difficult because sensors for detecting the sediment line (interface between clear water and sedimenting zone) and the solids content in the compression zone are not commercially available."

Jan 1, 1998

By H. L. Gibson, T. N. Setterfield, J. J. Watkins, R. W. Hodder

"Abstract - The McDougall-Despina fault set in the Noranda district of northwestern Quebec defines the eastern margin of the Despina cauldron, nested within the district-scale Noranda cauldron. The faults are stratabound in that they displace stratigraphy of the cauldron fill, but do not off-set the cauldron cover. The faults are occupied by dikes that acted as eruptive centers to volcanic members of the cauldron-filling sequence. Measurable displacement across the McDougall-Despina fault set is greater than 750 m, and coincident with post-cauldron volcanism. Feeder dikes cross-cut each other and are typically depleted in Na2O and CaO, and enriched in MgO, K2O, Fe2O3 and MnO relative to fresh flows. Economic and subeconomic massive sulfide deposits occur adjacent to the McDougall-Despina fault set at different levels over a stratigraphic thickness of 3000 m. These include the Corbet deposit, the subeconomic D-68 Zone deposits, and the subeconomic stringer zones of South Rusty Hill and Bedford Hill. Numerous copper occurrences and abundant hydrothermal alteration occur in and immediately adjacent to the fault set.The McDougall, Despina, and adjacent, parallel, ancillary faults define a synvolcanic fault set which controlled the location of magmatism, hydrothermal alteration and mineral deposition during the early evolution of the Noranda cauldron. Significant sulfide mineral deposition commonly occurred in proximity to the intersection of the McDougall-Despina fault set with northeast-trending synvolcanic faults. Recognition of synvolcanic faults is therefore a major objective of exploration programs for volcanic-associated massive sulfide deposits."

Jan 1, 1995