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By Fuzail Siddiqui

"The SIDMIN program aims at filling the mineral processor’s need to know the deportment of ‘minerals of interest’ not just ‘elements of interest’ that pass through the processing plants. Generally, chemistry is used as a tool of routine monitoring on site. Mineralogy, which is relatively much slower, is used more as a tool of research and post mortem investigations and these services are usually provided by a distant facility. The SIDMIN program enables site management to receive chemical and quantitative mineralogical reports on their critical samples daily, simultaneously and affordably.The author developed the SIDMIN program at ZCCM Nchanga Division where it continues to be a powerful tool for monitoring the efficiency of operations. Outlines are given of procedures for quick sample preparation and quantification of significant minerals in process samples. A specimen report is presented, which shows the format of reporting the contributions of individual minerals to metal losses at critical stages of the circuit. It is shown that SIDMIN provides timely information to management, about trends and abrupt changes in the quality of ore, and its processing, in a way never achievable by chemical analyses alone. This greatly helps in resolving the age-old problem of ‘bad ore’ or ‘bad operations’ on a day-by-day basis. For example increase in copper mica in the feed indicates excessive ore dilution during mining. Increased loss of free sulphides was traced to insufficient reagent conditioning time at the Concentrator. Persistent losses of leachable oxides at the Tailings Leach Plant were traced to inadequate leach residence time.SIDMIN is affordable because it can be implemented using basic optical microscopes, minimal quantities of micro-chemical reagents and custom trained site staff who demonstrate good colour perception and an ability to follow laid down procedures consistently."

Jan 1, 2000

By J. E. Dutrizac

"The end of an era in zinc metallurgy took place on July 31, 1976 when the horizontal retort furnaces of the National Zinc Company in Bartlesville, Oklahoma were permanently shut down (1) . For more than a century, horizontal retorting had been the most common method of producing zinc in the United States; it was a thriving industry in many parts of that country, especially in the natural gas belts of Oklahoma and Texas. With the Bartlesville closure, yet another metallurgical process has become an object of historical interest for North American metallurgists. Although shrouded in controversy, the origins of zinc metallurgy seem to date back at least 2000 years. Pyrometallurgical methods with carbon reductants are capable of producing zinc from oxidic zinc ores, but only above the boiling point of the metal. Although slow cooling results in re-oxidation of the zinc vapour by air or carbon monoxide, quenching yields liquid zinc; some form of rapid cooling, either accidental or intentional, was likely used by ancient metallurgists to liquify the metal. Zinc metal found in Athenian objects of the Roman era was likely of accidental origin. The Romans employed brass extensively for coins and ornaments(2) , and this was intentionally produced by the calamine process whereby oxidic zinc ores were added to molten copper under strongly reducing conditions. Zinc appears to have been known in China and India as early as 1000-1300 A.D., and was probably smelted commercially in those countries from the 14th century. Although the early metallurgical procedures were probably inefficient, they were able to produce zinc metal in significant amounts. The large heaps of zinc residues with clay retorts bear testimony to an early smelting industry of impressive magnitude. It is estimated that the heaps at Zawar, India alone represent the extraction of 100 000 tons of metallic zinc(2) In the 1730s the smelting of oxidic zinc ores was developed in England using a vertical retort method. In 1788 a British patent was granted for making zinc from zinc blends (ZnS) by roasting the ore in a coalfired reverberatory furnace, mixing the calcine with charcoal and smelting the mixture with suitable zinc condensation. The English process was very energy intensive, however, and early in the 19th century the Belgians developed a horizontal retort process for the reductiondistillation of zinc that was more fuel efficient. This technique was gradually developed into what came to be known as the Belgian process, the forerunner of the ""modern"" horizontal retort furnace."

Jan 1, 1999

By Michel Aubertin

Les haldes à stériles contenant des minéraux sulfureux réactifs constituent un milieu favorable à la production du drainage minier acide (DMA). Au sein de ces haldes, les processus physiques, géochimiques et biologiques qui mènent à la production du DMA sont nombreux et complexes. Un des aspects critiques qui affecte la génération de DMA est la distribution et le mouvement de l?eau dans les roches stériles. La modélisation numérique est un outil qui permet de comprendre, pour éventuellement contrôler, les mouvements de l?eau (et donc réduire la production du DMA) dans les haldes pendant la période d?exploitation de la mine et à sa fermeture. Plusieurs simulations numériques des écoulements non saturés dans des haldes ont été effectuées. Pour ces simulations, on a considéré divers types de matériaux, diverses conditions atmosphériques et diverses configurations géométriques. Les simulations réalisées montrent que l?on peut contrôler les mouvements de l?eau en introduisant des couches de matériaux fins intercalées dans les haldes formées de matériaux grossiers. Des couches horizontales ne sont cependant pas appropriées puisqu?elles peuvent, dans certains cas, favoriser la création de zones humides susceptibles d?amplifier les effets du DMA. Une faible inclinaison des couches de matériaux fins vers l?extérieur permet de palier à ce problème. Les couches inclinées favorisent un drainage des haldes vers la périphérie. Ceci a pour effet de garder sèche une grande partie des stériles et de réduire, par le fait même, la production du DMA.

Nov 1, 2002

By Yaw Boadi, Andrew McCallum, Sandy Gray, Yavuz Atasoy, Peter Wemyss

"Various full-scale test programs and installations of the InLine Pressure Jig (IPJ) have provided evidence that pre-concentration of the difficult to leach sulphide mineral through gravity can provide significant increases in economic recoveries. The continuous gravity concentrates are intensively treated either by re-grinding or Intensive Cyanidation. Data from various mine sites worldwide is presented. Treatment of complex ore bodies with this low cost methodology may render previously uneconomic ore bodies financially viable and assist in the recovery profile of transitional ore.INTRODUCTIONThe use of gravity is made extremely attractive in complex ore situations due to the low cost of operation, typically a few cents per ton operating cost and lack of chemicals.Gold mines which suffer from poor recovery due to complex mineralogy such as Stibnite, Arsenic, Carbon, Telluride, Silver and other pacifying agents such as Iron, which can form coatings, can all benefit from the process proposed in this paper. The key issue is not overall recovery as much as one of economic recovery. The key to this is maximised recovery at the lowest possible capital and operating cost. Other options such as flotation are reviewed but are not seen in many instances to be the panacea due to issues discussed in the paper. The use of the InLine Pressure Jig in the re-circulating load of the milling circuit is a cost effective means of recovering a sulphide/gold concentrate containing the complex mineral assemblages which require re-grinding and intensive leaching for optimised gold recovery.The benefits of Jig Assisted Grinding (JAG) are many and the challenge over the past years has been developing, understanding, implementing and evaluating the benefits of various flowsheet models. This has involved the reconciliation of results in plant scale trials back to the original laboratory test program. The following paper outlines the insights gained in this area through extensive work carried out by many people across both laboratories and plant sites in Australia and overseas. The examples in this paper are some of the work carried out on a few selected sites but similar work has been carried out on other sites such as Penjom, Granny Smith and Agnew. This work has eventuated in several installations which we believe have great importance in the future of the gold processing industry. They will lead the way forward to the modern all-gravity plants of the future.Compared to flotation, for the recovery of sulphides, gravity is a simple option. The simplicity generally translates to low capital and operating cost."

Jan 1, 2004

By Michel Aubertin

Les digues de retenue de résidus miniers devraient être conçues de façon à supporter les charges les plus défavorables qui puissent être anticipées. Les nombreux incidents survenus au cours des dernières années à travers le monde montrent toutefois que la stabilité de ces ouvrages reste encore problématique. Les cas de rupture les plus courants sont reliés aux glissements le long des pentes, à la liquéfaction des rejets, au débordement des bassins, ainsi qu?à l'érosion régressive et de surface. Après avoir rappelé la nature et l?importance des certains incidents récents, l?origine de ces problèmes est brièvement présentée. On aborde ensuite le lien entre les critères à adopter pour la conception des ouvrages et les risques associés à leur rupture. De nouvelles avenues pour aider à contrôler certains problèmes sont enfin discutées, en mettant l?emphase sur la codisposition des roches stériles dans le parc à résidus miniers.

Nov 1, 2002

By R. W. Hodder

"Archean lode gold deposits of both vein and chemical sedimentary types typically have major enrichments of certain rare elements, including Au, Ag, As, Sb, B, W, Se, Te and Bi, coupled with low or negative enrichments of the more abundant and mobile base metals, Cu, Pb and Zn. On the other hand, in massive base metal sulphide deposits Au, Ag, Cu, Zn and in some instances Pb are all enriched by a factor of 200 to 2000 t:'Jf'1pared to background and there is no large separation of gold relative to the base metals.The fluids from which gold was precipitated in veins were at temperatures of 320 to 480°C, at lithostatic pressure, had significant C02, and Na """" K; whereas the fluids which generated base metal deposits were at 250-300°C, at hydrostatic pressure, had C02 < < H20 and Na > > K.Many lode gold deposits are characterized by K, C02 and Si additions to their enveloping rocks, whereas base metal deposits typically have a fixation of Fe, Mg, Si and S in footwall rocks. Lode gold deposits may also have a relatively large halo of low-temperature oxidative, sadie spilitization in enclosing volcanic rocks, where seawater has later streamed into cooling stocks or flows that have initially acted to focus gold mineralizing fluids along thermal contraction fractures. The submarine environment is one hydrologically appropriate for the mixing of two initially independent hydrothermal systems, and the blending of their separate characteristics. Hence, lode gold and base metal massive sulphide deposits appear to be products of two distinctly different crustal and hydrological regimes. The former involves a high-temperature, high-pressure discharge of fluids which probably were generated during dehydration accompanying burial and progressive accumulation of volcanic-sedimentary sequences, with an additional influence of marine water in the near-sea-floor environment. The latter represents thermally driven convection of ocean water at lower temperatures and under hydrostatic conditions.Auriferous fluid systems with only minor base metal content could plausibly be generated during dehydration accompanying burial and metamorphism, when the water-to-rock ratio is low and halogen availability is limited by crustal abundance (- 60 ppm Cl). These two factors may constrain the uptake of the abundant base metals into fluids, but the solubility of rare elements is not constrained by limited fluid; and preferential uptake of Au along with other rare elements may be promoted if such elements compete more successfully for the limited halogens than the base metals, and/or have an alternative complexing agent such as CO or C()j-."

Jan 1, 1982

By R. J. Schafer-Frentz, T. G. Joseph, M. Curley

"Greenhouse gas emissions—specifically of carbon dioxide—are a concern in Canada, where industrial sectors such as mining are stringently regulated for carbon release. Cumulative emissions are positively related to fuel consumption, which is controlled by several factors. This study investigates one of these factors: the product of vehicle speed and running surface total resistance (TR; sum of rolling resistance and grade resistance). Results show that TR directly affects fuel consumption and emissions—a relationship that is mathematically predictable. Fuel consumption and emissions, which are principally associated with the durability or deterioration of wearing course materials, were analyzed to aid selection of road construction capping material of low rolling resistance. In the oil sands region in the province of Alberta, ground conditions change seasonally. Therefore, the annual fuel consumption for the same wearing course material was also compared. Results demonstrated that haul truck size was a contributing factor, but vehicle speed and TR more strongly influenced fuel consumption and emissions. ¦ KEYWORDS Carbon dioxide, Emissions, Fuel consumption, Grade resistance (GR), Greenhouse gas (GHG), Haul truck, Rolling resistance (RR), Total resistance (TR) RÉSUMÉ Les émissions de gaz à effet de serre (GES), et particulièrement celles de dioxyde de carbone, sont un problème au Canada, où les secteurs industriels tels que l’exploitation minière sont rigoureusement réglementés pour leurs émissions de carbone. Les émissions cumulées sont indéniablement en lien avec la consommation de carburant, qui est contrôlée par plusieurs facteurs. Cette étude examine l’un de ces facteurs, à savoir le produit de la vitesse du véhicule et de la résistance totale de la surface de roulement (la résistance totale, ou RT, est la somme de la résistance au roulement et de la résistance due aux rampes). Les résultats montrent que la RT affecte directement la consommation de carburant et les émissions, un lien qui est mathématiquement prévisible. La consommation de carburant et les émissions, qui sont principalement associées à la durabilité ou la détérioration des matériaux composant la couche d’usure, ont été analysées afin de contribuer à la sélection de matériau de recouvrement pour la construction de routes ayant une faible résistance au roulement. Dans la région des sables bitumineux de l’Alberta, les conditions au niveau du sol changent à chaque saison. Ainsi, la consommation annuelle de carburant pour le même matériau composant la couche d’usure a aussi été comparée. Les résultats ont montré que, si la taille des camions de transport est un facteur déterminant, la vitesse des véhicules et la RT influencent davantage la consommation de carburant et les émissions. ¦ MOTS CLÉS camion de transport, consommation de carburant, dioxyde de carbone, émissions, gaz à effet de serre (GES), résistance au roulement, résistance due aux rampes, résistante totale (RT)INTRODUCTION In Canada and around the world, global climate change has become a topic of great concern and discussion. Pres-sure on world leaders to quickly reduce their carbon footprint is prevalent, prompting new standards and regulations in various industries, including mining and oil and gas. In 2017, the Government of Alberta implemented a carbon tax. The majority of mining activities in this province are truck-shovel operations, where a large fleet of ultra-class trucks is loaded by shovels. Ultra-class haul trucks, classified as those with a capacity of 218–363 tonnes (t), emit high levels of carbon as they travel to processing entry points and waste dumps as designated by the mine plan and mine dispatcher. Mined ore and waste is typically moved over two 12-hour shifts per day throughout the year."

Jan 1, 2019

RÉSUMÉ L’estimation la plus précise possible des coûts de minage est d’extrême importance pour les études de préfaisabilité afin de diminuer les risques financiers des projets miniers. Les méthodologies existantes d’évaluation des coûts de minage ne permettent pas de les évaluer avec des marges d’erreur acceptables tout au long de l’évolution des projets miniers. Elles visent à évaluer les coûts unitaires de minage des études préliminaires de faisabilité, pour les principales méthodes d’exploitation, en prenant pour l’hypothèse que ces coûts dépendent principalement du taux d’extraction journalière. Si cette hypothèse peut être justifiée pour l’évaluation du coût d’opération, elle est fort discutable pour l’évaluation des coûts de minage. Pour démontrer que cette hypothèse est inadéquate nous avons analysé la méthode d’exploitation la plus populaire sur le continent nord-américain c’est à dire celle par chambres vides avec retrait horizontal (Hr – Horizontal retreat), ou « Longhole » et celle avec retrait vertical (VCr - Vertical Crater retreat). Il ressort de cette analyse que les coûts unitaires de minage dépendent principalement des conditions géotechniques du massif rocheux et de la largeur du gisement et non pas du taux d’extraction journalière du minerai.

Jan 1, 2010

By Tiziana Apuani

The study refers to an area of about 70 km2, extended in the Italian Central Alps along the the San Giacomo Valley where different civil and mining works are present The regional geological setting is related to the Pennidic Nappe arrangement, characterized by the emplacement of sub-horizontal gneissic bodies resulting from the Mesoalpine isoclinalic folding of crystalline basements, emplaced throw East, and separated by matasedimentary cover units. The investigated geological rocks, belong to the ?Tambò?Unit, overlapped by its meta-sedimentary cover and by the ?Suretta? Unit. The tectonic contact gently dips to the E?NE. The valley, furrowed by the Liro Torrent, follows a N?S striking tectonic lineament, almost parallel to the nappe contact. A number of more then 70 sites, distributed in the studied area, were chosen and detailed structural and geomechanical field surveys were performed to characterize the rock masses, its intact rock and discontinuities. The procedure identifies the number of joint sets, their representative orientation, the set spacing, the type of movement, the amount of dilatation, the degree of alteration, the roughness coefficient, the presence and nature of infill. Rock mass quality indexes, such as the Rock Mass Rating (Bieniawski, 1989) or the Geological Strength Index (Hoek et al. 2002) have been evaluated in each surveyed site. The work is a contribute in assessing how the geometrical and geomechanical properties of the rock masses can be regarded as regionalized variables. The spatial distribution of these properties is a function of the geological and structural phenomena at which the rock masses have been subjected. The presented geostatistical analysis regards the spatial variation of the orientation of the most representative joint set.

May 1, 2009

En quoi consistent les études de suivi des effets sur l?environnement (ESEE)? Les ESEE constituent une méthode de suivi scientifique que l?on peut employer pour déterminer la santé des écosystèmes aquatiques (qui peuvent être touchés par l?activité humaine) et l?efficacité des mesures de protection de l?environnement. Les ESEE sont des évaluations scientifiques itératives du poisson, de l?habitat du poisson et des ressources halieutiques. Le programme comporte des phases séquentielles de deux à six ans de suivi, d?interprétation et de compte rendu au cours desquelles la fréquence et le type de suivi dépendent des résultats des études précédentes. Le programme des ESEE pour les mines de métaux est fondé sur un accord conclu à l?unanimité entre les intervenants. Les exigences du programme et les guides techniques connexes ont été élaborés à la suite d?une consultation multilatérale à laquelle ont participé les représentants du secteur privé, du gouvernement et des collectivités. Toutes les mines assujetties au Règlement sur les effluents des mines de métaux (REMM), aux termes de la Loi sur les pê ches, doivent procéder à une ESEE dans le cadre de l?autorisation qu?ils ont reç ue de rejeter des effluents. Le REMM a été enregistré le 6 juin 2002 et publié dans la Partie II de la Gazette du Canada le 19 juin 2002 (SOR/DORS/2002-222).

Nov 1, 2002

By Lyn Jones, Mike Bratty, Rick Lawrence, David Kratochvil

"The treatment of water is required at many mining operations to remove metals and prevent the discharge of contaminated water to the environment. In other cases, water treatment is used to provide better quality water for recycle to the processing plant, or to process bleed streams in hydrometallurgical operations in order to prevent deterioration in metallurgical performance or process equipment. BioteQ Environmental Technologies Inc. has developed and commercialized the BioSulphide® Process which can provide an alternative for these treatment needs and which can also be used for profitable metal recovery, particularly in cases where conventional metal winning techniques are not economical. The BioSulphide® Process is a high rate anaerobic biotechnology for on-site production of H2S from sulphur species, although for smaller flows and metal loadings, the use of chemical sulphide reagent might be more cost effective. Both new projects and existing commercial operations, used for removal and/or recovery of copper, nickel, and zinc, and which range in sulphide generating capacity from 50 kg/day to 3.7 tonnes/day, are discussed. Particular focus is placed on the results of operations at the Raglan Mine in Northern Quebec where dissolved nickel is removed from contaminated water at a high efficiency through the precipitation of nickel sulphide. Plant effluent is discharged directly to the receiving environment and the high-grade nickel sulphide product is combined with the nickel flotation concentrate produced at the mine. The plant at Raglan will replace the existing conventional water treatment plant and will eliminate the need for on-site storage of treatment plant sludge.INTRODUCTIONThe BioSulphide® Process, which produces low cost H2S for use in selective metal precipitation, offers a low capital cost alternative which can operate efficiently and cost-effectively within a wide range of flows and solution grades. Since the technology can be used to recover metals from solutions with low flows and metal grades, the technology is also applicable to environmental applications for water treatment, with the sale of recovered metals providing an offset to treatment costs. For environmental control, the technology has a distinct advantage in being able to meet strict effluent discharge criteria due to the very low solubility of metal sulphides. To date, BioteQ Environmental Technologies has designed and constructed three plants for metal sulphide precipitation, with another three projects in the advanced development stage."

Jan 1, 2006

By L. Li

The backfilling of underground stopes is a common practice throughout the mining industry. The stresses imposed by the backfill on the surrounding rock mass need to be assessed because of their influence on ground stability and on the hydro-geochemical response of the fill material. There is, however, a complex interaction between the relatively soft backfill and the much stiffer adjacent rock mass. In recent years, the authors have presented results from investigations conducted on stress distributions (obtained numerically and analytically) in and around backfilled stopes with (sub)vertical walls. In this paper, the influence of stope inclination and of backfill properties is evaluated. Results indicate that, in general, the vertical and horizontal stresses in inclined stopes are close to, but somewhat smaller than the stresses in vertical stopes. Nonetheless, significant differences can be observed in some cases, especially for the vertical stress along the inclined central line and along the hanging wall. It is further shown that neglecting deformability in limit equilibrium analyses is an acceptable assumption. However, Poisson?s ratio and the dilatancy angle, usually neglected in limit equilibrium analyses, may have significant effect on the stress distribution. Results also confirm that the backfill strength parameters (cohesion and friction angle) are critical factors required to properly evaluate the stress distribution, at least within a certain range of parameter values.

May 1, 2007

By Timothy W. Ellis

Wire Bonding is the dominant IC interconnection process presently used in the semiconductor assembly industry (1). The flexibility, adaptability and cost of wire bonding will continue to keep it as the key process for the interconnection of integrated circuits to substrates. However, wire bonding still has certain technological hurdles to overcome if it is to continue following the semiconductor roadmap (2). Particular issues which need to be addressed include low overall tensile strength, low elastic modulus, low shear per unit area and mechanical loop stability of Gold based micro-alloys. The ability to produce ?Deformation Process Metal-Metal Matrix Composites? (DMMCs) is based upon the deformation nature of immissible metallic systems. For reference, the Gold (Au)-Molybdenum (Mo) phase diagram is shown in Figure 1 (3). By inspection of the diagram, Au has a very low solubility for Mo, while Mo has essentially no solubility for Au. This is the metallurgical analog of oil and water. In the Au-Mo case, this is particularly troublesome when producing precursor ingots of the alloy to be formed into wire products. In Table 1, the melting points and densities are shown for Au and Mo. As shown, the melting point of Mo is significantly higher than Au, and is very close to the boiling point of Au (2856°C). However, Au?s density is higher than that of Mo. As such, conventional casting techniques are not suitable, since solid Mo would float off the surface of an Au melt thus depleting the matrix of its alloy addition. In this work, two-phase composite wires were produced by deformation processing to develop an interconnection wire with elevated tensile strength, modulus and shear to those commonly available in the market (4). This technology has been used previously in the production of high strength electrical conductors particularly for high field pulsed magnets (5).

Oct 1, 2003

By K. Swedburg, M. Samuels

"The New Afton concentrator was commissioned in June 2012, reaching the design milling rate in September 2012. By late 2013, through a campaign of optimization and de-bottlenecking, it was recognized that the installed plant was capable of greatly exceeding the design throughput of 11,700 tpd. Because the value of the metal contained (by increasing the plant feed rate) exceeded the offsetting losses of copper and gold recovery (as the operation moved to a coarser grind), the concentrator feed rate was strategically increased with support of New Gold, while the operations team was given a mandate to evaluate, and then implement, flow sheet options that could re-establish the original design criterion grind target and achieve the corresponding improved recovery. Broadly, the two options implemented were the addition of a tertiary grinding stage consisting of Metso Vertimill® prior to rougher flotation (in order to address the grinding required at increasing throughput by increasing the power), and the addition of three Woodgrove Staged Flotation Reactors (SFR) added to the cleaner circuit after regrind of the rougher concentrate (to address the increased mineral loading to the cleaner circuit). Through test work, it was anticipated that the SFRs would be capable of achieving final concentrate grade in a single pass without the integration of recirculating loads, a strategy sometimes referred to pre-cleaning. This paper describes the expectations generated for the Woodgrove SFR unit operation through pilot plant testing on site, and compares those results with the performance of the expanded circuit that exceeded the original design criterion of P80 160 µm, which was commissioned in the second quarter of 2015.INTRODUCTIONThe New Afton concentrator, located near Kamloops, BC Canada, commenced operation in June 2012. The mill achieved the design throughput of 11,000 tonnes per day average during the month of September 2012 and, following various operational optimization efforts (O’Hara et al, 2015), achieved the design p80 grind size of 160 µm at the design milling rate in July 2013.During August 2013, trials were carried out to determine the throughput rate limits of the mill circuits and to evaluate mill metallurgical performance at higher rates. Milling rates up to 15,500 dmt per 24 hours were achieved during this trial, demonstrating potential capability for sustained milling rates exceeding the nominal design capacity. As was expected, the higher milling rates resulted in a coarsening of the grinding circuit product size, and resulted in marginally lower recoveries in the rougher flotation circuit. Despite the lower recoveries, the higher milling rates resulted in higher metal production and the financial analysis favored running at rates of at least 13,000 tonnes per operating day, with the higher cash flow in the near term offsetting the value of metal production loss at the end of the mine life (due to the short term increase in the rate of reserve depletion). Milling rates were sustained above 13,000 tonnes per day through the second half of 2013, and increased above 14,000 tonnes per day by mid-2014 (Figure 1)."

Jan 1, 2016

By J. J. Montoro

The influence of blasting on the excavators’ efficiency, defined as mucking rate (amount of rock mucked per unit time) and mean bucket load (amount of rock loaded in each bucket operation), is investigated. Rock characteristics, blasting parameters (drill pattern, explosive energy, and charging), and the excavator’s performance (truck loading time and number of buckets to fill a truck) were monitored in eleven blasts in an open pit iron ore mine. ANFO, ANFO/emulsion blend, and watergel were used in the blasts and the powder factor was varied between 0.98 and 1.45 kg/m3. The mean bucket load is mainly affected by the bucket size, which is independent of the blasting parameters. Besides the relation with the mean bucket load, the mucking rate was found to be positively correlated with the explosive energy, whereas no significant correlation with the rock properties was found. The analysis of the data, together with other published works, suggests a non-monotonic relation of the mucking rate with the powder factor, with a maximum mucking rate at a certain powder factor. This is especially true when the useful work of the explosive per unit rock volume is used rather than the classical mass powder factor and when only the amount of explosive above grade is considered.

Jan 1, 2007

By Leslie F. Sawatsky

Raw water import requirements for oils sands mines depends mainly on factors such as ore processing rate, ore material characteristics, tailings processing technology, tailings storage systems, process water storage operations, the phase of tailings production, and non-recoverable seepage losses from tailings ponds. These factors can be readily quantified to calculate raw water import needs. Nevertheless, mine water balance continues to be misunderstood by some regulators, stakeholders and possibly even mine operators. Confusion over consumptive uses has led to a focus on recycling which is not necessarily applicable to a closed circuit water management system. Some water conservationists focus attention on raw water intake rules instead of the technical decisions that control consumptive uses. Typical oil sands mine water balances for various types of tailings operations, are analyzed to illustrate the effect of controllable and uncontrollable parameters as well as major options that need to be explored for reducing water demand. Uncontrollable parameters including tailings fines content, oil content of ore, connate water, mine depressurization water inflows and surface water hydrology. Controllable parameters include storage operations, advance water supply ahead of mining operations, type of tailings operation, net tailings pond seepage losses, and tailings impoundment operations. Potential reductions of raw water supply rates may be obtained by providing greater on-site storage to attenuate fluctuation in water demand, advance water accumulation prior to mine start up, early commencement of CT operations, thickened tailings disposal and paste technology. Water conservation measures should be focused on reducing on-site process water storage and water content of tailings material.

May 1, 2004

By P. Marcotte, G. LeBlanc, S. Ouellette, J. Boutin

"To characterize noise and vibration sources of different types of mining equipment used in underground mining, the authors performed a study in eight Quebec mines on 28 pieces of equipment. This paper presents the procedure followed to select the equipment to be evaluated, and the low-cost acquisition system developed to perform multichannel time-domain data acquisition in harsh environments. It also presents the results obtained for the noise level produced by the equipment and for handarm and whole-body vibration exposures.RÉSUMÉ Dans le but de caractériser les sources de bruits et de vibrations de divers équipements miniers utilisés sous terre, les auteurs ont étudié 28 équipements dans huit mines du Québec. L’article présente la procédure suivie pour choisir les équipements à évaluer ainsi qu’un système multicanal à faible coût développé pour acquérir des données dans des environnements difficiles. Il présente aussi les résultats obtenus pour les niveaux de bruit produit par les équipements et pour les expositions main-bras et du corps entier aux vibrations."

Jan 1, 2015

This paper discusses how elemental analysis of conveyed bulk flows in real time using PGNAA (Prompt Gamma Neutron Activation Analysis) technology has resulted in significant improvements in advancing plant control in mineral processing operations. Basis of operation of the PGNAA through belt, full stream, continuous, multi-elemental, real time analysis technology is explained. Capabilities and limitations in plant operating environments are discussed including comparison with other real time, online technologies through review of published information available for on-conveyor minerals applications. Case studies demonstrate benefits provided by this technology in two operating mines. An iron ore company had prior experience with the PGNAA analyser technology, implementing an early model in a minerals application in 2003 to develop confidence in its measurement performance and usefulness of the data. A number of analysers were subsequently included throughout the new plant design for extensive measurement and control of conveyed bulk flows, from conveying after mining through to rail load-out. A copper-gold company installed an analyser to address copper ore blending issues where an on-belt system was the only viable option for the degree of control required. Analyser suitability was evaluated through test work on site samples to determine customised multi-element precision guarantees for each application. Analyser results from normal operation are compared against laboratory analyses of multiple cross stream samples collected from conveyed flows to assess performance. Both projects discussed were able to realise benefits previously unattainable for plant quality control, surpassing capabilities of traditional technologies which were either unsuitable for measuring conveyed flows with adequate accuracy or in real time. Equipment payback within a few months was achieved for both sites. Through proven performance in these applications, the companies consider the technology an essential component in advanced plant control necessary in new process flow sheet designs, rather than an optimisation tool.

Jan 1, 2014

By Catherine T. Ziten

Introduction ?Environmental assessments required for permitting ?Focus on ammonia produced through mine construction & blasting ?Water quality guidelines: federal, provincial, IGO ?Reported values are typically estimates from other projects ?Predictive modelling of ammonia aimed to assist planning

May 1, 2009

By B. P. Simser, R. K. Brummer, A. Mortazavi, P. P. Andrieux

"A large-scale panel destress blast was fired at Brunswick mine in the fall of 1999 in order to reduce the ground stresses in a critically important neighbouring mining region. This work, sponsored by the Mining Division of CAMIRO and Brunswick mine, consisted in heavily choke-blasting — and subsequently leaving in place — a massive waste sulphide pillar in the southwest end of the 1000 m level. This paper describes the approach and design methodology used to try to maximize breakage in the rock mass in the area to destress, while minimizing damage to critical infrastructures in the vicinity. The loading operations, as well as the results of the blast — in terms of its field performances, as recorded by near-field blast vibration monitoring equipment, visual postblast assessments and measured impact on the regional stress field — are discussed as well. A brief comparison between the measured stress changes and inelastic numerical modelling of the test site is also presented.Un tir à grande échelle de relâchement des contraintes dans un pilier a été effectué à la mine Brunswick à la fin de l’automne 1999 dans le but de diminuer les contraintes de terrain dans une très importante zone de production adjascente. Ces travaux, financés par la division minière de CAMIRO et la mine Brunswick, consistaient à tirer violemment sans aucune face libre, et à laisser en place, un pilier de sulphures massifs au sud-ouest du niveau 1000 m. Cet article décrit l’approche et la démarche conceptuelle utilisées pour tenter de maximiser les fractures dans le pilier visé, tout en minimisant les dommages collatéraux à des infrastructures critiques se trouvant dans les environs immédiats. Les opérations de chargement des explosifs et les résultats du tir — en termes de ses performances, telles qu’évaluées par de l’équipement de monitoring rapproché des vibrations de tir, d’observations visuelles, et de son impact sur les contraintes de terrain locales — sont également discutés."

Jan 1, 2003