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By Ronald L. Bruening

IBC has developed a cost effective MRT process for the selective extraction and recovery of gold, copper, and a mixture of other base metals from mine leach cyanide solutions. This is a two-stage system in which the gold is first recovered selectively as a high purity salt. The copper is then recovered separately as a sulfate salt. The other base metals are then collected as a cyano anion concentrate. Three different SuperLig® materials are used. The first stage can be used alone on gold leach solutions where copper and other base metals are not a problem. The two or three stage system is used when the base metals build up in the leach solution, resulting in increased costs. The cyanide or cyanide/cyano anion concentrate can be recycled back to the leach solution until the build-up of other salts, etc. becomes too high, or this too can be controlled with a percentage bleed stream.

Oct 1, 2003

By Fidelis T. Suorineni

Rapid drifting enables quicker access to orebodies, higher production rates and a resultant reduction in production cost. The Mining Innovation, Rehabilitation and Applied Research Corporation (MIRARCO) funded by the Canadian Mining Industry Research Organization (CAMIRO) has developed a methodology for safe rapid drift development within the underground metalliferrous mining industry in Canada According to industry survey, about 36% of drift development cycle time is spent on support installation. MIRARCO has developed a methodology for safe rapid drift development based on minimizing time spent on support installation. The methodology includes a critical review of the rockmass classification systems, examination of current support practices in the mining industry and civil tunneling, review of rapid drift development practice in South Africa, introduction of risk hazard procedures to account for material property variability and the development of a WIZARD as a quick decision-making tool for the implementation of the procedures. A comprehensive field data collection procedure was put in place and data collected from various mines to verify and calibrate the support selection rationale. The findings of the research programme resulted in the development of an improved rockmass classification system and showed that construction effects have drastic influence on support levels but is often not accounted for in assessing support levels. Stress effects and structurally controlled failures are the other important factors to take into account in rapid drift development. Three support classes were established for safe rapid drift development as No Systematic Support, Light Support and Strong Support. The support levels took into account cost, rate of installation and safety based on compatibility with ground characteristics. This paper describes the methodology for safe rapid drifting within the underground metalliferrous mining industry in Canada and highlights the key issues and major drivers behind their continued development at the Geomechanics Research Centre within MIRARCO.

May 1, 2004

By Dean Lindsay, Inna Dymov, Mariam Melashvili, Jim Smolik, Chris Fleming

"This paper presents results from the proposed cyanide detoxification circuit for Seabridge Gold’s KSM project. The proposed flowsheet uses a two-stage CCD (counter-current washing/decantation) circuit to transfer the flotation products CIL(carbon-in-leach) barren solution to a SART process (Sulphidization, Acidification, Recycling of precipitate, and Thickening of precipitate) to recover copper and free cyanide from the copper cyanide complex. The SART barren solution is then treated by an AVR process (Acidification, Volatilization of HCN gas, and Reneutralization) to concentrate the cyanide that was liberated in SART for recycling to leach. The washed CIL barren pulp (the CCD underflow) is treated with the SO2 /Air process to oxidize residual cyanide.The goal of this complex flowsheet is to recover and recycle as much cyanide as possible and produce a final effluent containing less than 0.5 mg/L copper and CNWAD at the lowest cost. The SO2/air process is capable of achieving low residual CNWAD (<1 mg/L) in the final product, but the persistence of aqueous copper above the target level has been detected in the treated solution in some instances. The expected high concentrations of copper and cyanide in the KSM CIL barren ( >200 mg/L each species) and the difficulties this might create for the SO2 /air process was a key factor in the decision to consider including the washing, SART and AVR steps in the project flowsheet.The target concentrations of CNWAD and Cu were readily achieved after aging the SO2 /air treated pulp, as would occur in a tailing or polishing pond. This suggests no additional treatment will be required to sustain low levels of these species in the final plant effluent."

Jan 1, 2015

By Mika Muinonen

"Dewatering of nickel concentrate at the INCO Thompson integrated mine-metallurgical site takes place within the smelter plant. The eight original 60 foot diameter cable torque thickeners of which four were operational and eight Dorrco internal drum filters have been replaced with a single Outokumpu high rate thickener and a single Lasta pressure filter. The modernization has resulted in a filter cake which has a more stable and lower moisture content. Control of the entire dewatering process has been improved and costs have been reduced.Typical filter cake produced from the Dorrco filters during processing of high tonnages of Birchtree mine ore was ~20% moisture vs. ~13% moisture for concentrate produced from the Thompson mine ore. The high moistures were correlated with the amount of fine magnesium silicate gangue in the concentrate. As Birchtree ore processing rates have increased, this filter cake moisture became unacceptable because of material handling problems and the impact on furnace metallurgy. The Dorrco filters were replaced with the Lasta filter in 2003 that has consistently produced filter cake at ~11% moisture.This paper summarizes the piloting, design, installation and commissioning of the modernized dewatering circuit.INTRODUCTIONThe Thompson integrated nickel processing facility was built in 1958 and originally consisted of a mine-mill-smelter and, soon after, a refinery.Nickel concentrate is pumped from the mill as a dilute slurry directly to the smelter facility ~200 meters along an unheated pipe trestle. Originally, nickel concentrate was de-watered using up to 8 conventional 60-foot diameter thickeners and 8 internal vacuum drum filters."

Jan 1, 2006

By Jon R. Maki

"EVTAC, an iron ore mine in Minnesota, had trouble meeting the customer’s pellet silica requirements. In addition, the mine plan was moving towards a lower grade ore and funding was not available for plant improvements to compensate for the change in ore or improving quality. Small changes to optimize various processing equipment resulted in significant improvements in both quality and productivity; for example, productivity on one mill line increased by 10% while producing lower silica concentrate. This paper will provide the methodology that allowed EVTAC to improve quality and productivity through process optimization with little capital investment.INTRODUCTION EVTAC, an iron ore mine in Minnesota, had trouble meeting the customer pellet silica requirements. In addition, the short-term mine plan was changing to a lower ore grade. Because of limited funds, EVTAC did not have the capital for investing in the plant to compensate for the ore change or to make improvements to lower product silica levels. Small changes to optimize process equipment resulted in significant improvements in quality and productivity; for example, one mill line feed rates increased by 10% while also producing a higher quality concentrate. These changes were sufficient enough to allow the mine to lower the target ore grade beyond their initial goal. At one time, a $3M flotation facility was considered as a way to meet quality with the new ore grade. However, the process changes were able to accomplish the same silica reduction with roughly a $50,000 investment in VFDs for sump controls. This paper will discuss some of the modifications that allowed EVTAC to meet the quality and production objectives with little capital investment. It also discusses the methodology used to make these process improvements."

Jan 1, 2014

By Michel G. Grenier

Compliance with Diesel Particulate Matter (DPM) exposure regulation is currently performed using timeweighted average (TWA) sampling on underground mine workers. These samples are collected in the span of an entire shift and the resulting concentrations are compared to a legislated exposure limit. While this is very useful to determine the exposure level of an individual to DPM, it fails to clearly identify causes of exposure and highlight opportunities that could help reduce the exposure of workers in the course of the work shift. Real-time DPM monitoring measures the worker?s exposure as a function of time and helps identify circumstances where corrective actions can be taken or design changes can be made by the individual or the employer to reduce the overall exposure of the worker and peers. This work focused on obtaining DPM concentrations using a real-time polycyclic aromatic hydrocarbon (PAH) monitor. The aim was to demonstrate that this instrument, while not a direct DPM analyzer, was able to provide a concentration profile that could easily be linearly correlated to standard TWA elemental carbon measurements. In addition, several instances of improvements that could be implemented to reduce the exposure of underground employees were demonstrated.

May 1, 2010

By S. Hunt, D. de Vries

Kansanshi Copper Smelter began operation in March 2015. The smelter features a single Isasmelt furnace for smelting, one 6-in-line electric furnace for matte-settling and slag-cleaning duties, four Peirce- Smith converters and two rotary anode furnaces. A 1,450 t/day oxygen plant and a 4,085 t/day sulphuric acid plant are included in the smelter operations. This paper gives an overview of the operational performance to date with summary data for each smelter section. Challenges such as an unforeseen refractory failure in the Isasmelt furnace in 2016 are discussed. Design improvements around the electric furnace are mentioned. Plans for potential future improvements are put into context. A consistent focus on operations, maintenance and continuous improvement has seen the smelter easily achieve its nameplate capacity of 1.2 million tonnes per annum of copper concentrate throughput. The smelter now operates consistently at a concentrate throughput rate of 1.38 million tonnes per annum of copper concentrate. INTRODUCTION The smelter was commissioned in March 2015. Design and commissioning of the smelter have been discussed by de Vries, Hunt, Hanschar and Louie (2016). The smelter rapidly ramped up to achieve nameplate production (1.2 million tonnes per year concentrate) and in 2018 operated consistently at the rate of 1.38 million tonnes per year concentrate. This paper presents major operational data for each section of the plant and describes significant events and improvements during the first four years of operation. The smelter flowsheet is shown in Figure 1.

Jan 1, 2019

By Panagiota Tsolis-Katagas, Basilios Tsikouras, Tassos A. Grammatikopoulos, C. Katagas

"Mineralogical techniques including microscopic methods, reflected and transmitted light microscopy, Cathodoluminescence (CL) and Scanning Electron Microscopy equipped with an Energy Dispersive Spectrometer (SEM-EDS), are useful in determining the quality of industrial minerals. They are essential for studying ores and metallurgical products including the evaluation of physical characteristics of the mineral, paragenetic relationships, associations with possible deleterious contaminants (e.g., sulphides), spatial distribution within the ore zones and liberation characteristics. The methods are inexpensive, and provide quick identification and distinction among the industrial minerals and the gangue minerals in a section. Additionally, SEM is necessary to reveal complex textural sequences and 3-D measurements of minerals and quick semi-quantitative analysis.Common analytical methods include Electron Microprobe Analyses (EMPA) and Whole Rock Analysis (WRA) (commonly with XRF and ICP) for major and trace elements. The EMPA analyses of industrial minerals provide information on the purity of the analyzed grains as opposed to the bulk chemical analyses that may be misleading due to contamination by other associated common “gangue” minerals. These techniques have been implemented for the case studies of wollastonite, V-magnetite and muscovite. Therefore, these methods can provide extremely useful information and lead to the implementation of a successful pilot-testing programme.MINERALOGICAL EVALUATION OF DEPOSITSDespite their considerable and increasing economic importance, industrial mineral deposits have traditionally been neglected by economic geologists, and are only rarely the subject of the detailed analysis widely lavished on metallic mineralization. Moreover, in that they generally represent concentrations of “normal” rock-forming minerals, albeit commonly with particular textural and/or geochemical features, they have tended to fall between the mainstream of petrogenetic studies and mineral deposit research (Grammatikopoulos 1999). For many industrial minerals, little attention has been paid to the factors responsible for their local concentration as large and high-grade bodies. This comparative neglect has particularly been the case for minerals such as talc and wollastonite, widespread in metamorphic rocks, in which they are reasonably interpreted as components of assemblages derived, respectively, from pelitic sediments, ultramafic igneous rocks and siliceous limestones."

Jan 1, 2003

By Gregg Vickell

"High tonnage, low grade gold mines such as Omai’s afford economies of scale that are unto their own insufficient to sustain profitability at today’s depressed gold price. Complimenting profitability objectives is the perpetual challenge to reduce operating costs and optimize unit operating efficiencies while being ever vigilant of issues such as environmental control.Key to achieving these objectives at Omai are throughput and availability gains, gold recovery improvements, cost cutting, a skilled workforce and reliable power generation.This paper attempts a cursory review of startup-to-date plant performance advances and future performance-driven objectives.INTRODUCTIONCommercial gold production at Omai commenced in January 1993 with annual output climbing to 250,000 opy by the end of 1994. A mill expansion completed in August 1996 increased gold production to 340,000 opy by the end of 1997. Current milling capacity is 20,000 in tpd (nom.) with actual capacity exceeding 24,000 mtpd on occasion depending on ore size and competency. Mill feed consists of hardrock (andesite, quartz diorite and rhyolite) and softrock (saprolite, laterite) at a nominal ratio of 70:30, respectively. Present day average weighted grade of the feed is 1.4 g/t gold.PROCESS DESCRIPTIONPrimary crushing, ore handling and the original 12,000 mtpd hard and soft rock SABC mill, hereafter referred to as Mill ‘A’, remains essentially as documented by Konigsmann (1 994) complete with poststartup modifications. The mill expansion, hereafter referred to as Mill ‘B’, features an 8000 mtpd hard rock SABC grinding circuit similar in configuration to Mill ‘A’ and differing only in equipment size. Mill ‘B’ includes a 9000 H.P.,reversible variable speed , single pinion drive, 32 ft. x 15 ft. SAG inill , a 7 ft. short head pebble crusher and two parallel 5400 H.P., 16.5 ft. x 30 ft. ball mills with dedicated cyclone packs consisting of D26 hydrocyclones."

Jan 1, 1999

By R. Knapp, R. Firlotte

"Les Terrains Auriferes (LIA) Property, formerly the Malartic Goldfield (Goldfield) mine, ceased its remaining milling operations in the fall of 1994. During the early years of mining, the mill processed a non-sulfide ore with substantial carbonate mineralization.In 1977 after an extended shutdown period, ore from a nearby property, Bousquet, was processed at the mill. That ore contained larger quantities of sulfides, and unlike the old tailings, had acid generating potential.Upon closure of the L TA mill, the closure options considered for the L TA site were to cover with:1. a thin cover of 0.5 metres of borrow material (sand and gravel) to achieve basic erosion protection/stabilization; collect acidic seepage and treat with lime.2. a 2 metres of non-acid producing tailings; final surface to be vegetated.3. an engineered oxygen barrier consisting of a multi-layer cover; final surface to be vegetated.The paper presents the technological and economical methodologies that were used to select the closure alternative, describe the associated construction challenges that were faced with the implementation of the multi-layer cover concept and presents preliminary results on the cover's performance.In addition to being the first full scale demonstration of this type of multi-layer engineered oxygen barrier cover technology, this project had the advantage of using non acid producing mine tailings as part of the reclamation solution."

Jan 1, 1997

By Jocelyn Bouchard, Claude Bazin, Sami Makni, Rolando Quispe

"Finely disseminated minerals in ores require intensive size reduction to achieve sufficient liberation for the subsequent concentration process. The use of small grinding media in conventional ball mills as a replacement for the usual 2.5 to 3.8 cm balls (1.0 to 1.5 in) produces a finer size distribution at a lower power drawn by the mill motor. However, the conditions ensuring a successful application of using small media for fine grinding are still not fully understood and some plants faced issues to keep the newly introduced steel charge inside the mill during industrial trials. The retention conditions of small media are investigated in this paper using a continuously operated 40 x 40 cm laboratory grinding mill. The tests assess the effect of the steel charge level, the slurry solids concentration and the feed rate on the rate of ejection of the grinding media. The dominant variable is found to be the filling of the mill with the grinding media, followed by the mill feed rate. Results show that increasing the slurry solids concentration within a grinding mill may be favorable for the retention of the media inside the mill.IntroductionProcessing of complex ores often requires the use of fine grinding to liberate finely disseminated minerals. Grinding requirements for a P80 of less than 0.02 mm are not uncommon, and different grinding mills are available for such application (Leonida, 2014; Pease et al., 2006; Davey, 2006; Orford et al., 2006; Nesset et al., 2006). Even conventional horizontal ball mills charged with of 2.5 cm or larger grinding media can be used for fine grinding. However, simulation (Orford and al., 2006) and plant observations (Alves and L-Bouchet, 2005; Brisette, 2010; Brisette and Roman, 2012) demonstrated the advantages of using smaller grinding media in terms of size reduction and energy consumption."

Jan 1, 2015

By A. Pratt

Portland cement is primarily used to solidify backfill in underground mine workings and it represents a major cost in mining operations. CANMET-MMSL has invented an alternative binder technology that does not contain any amount of Portland cement and is made using waste materials, such as development rock and smelter slag. The technology has been successfully tested with many types of base metal and ferrous slag. Research conducted in collaboration with several mining operations in Canada has shown that the CANMET-MMSL binder has considerable potential as a replacement for Portland cement in mine backfill. An integral part of the overall mining operation, backfill is used for two main purposes: safety and environmental remediation. Depending on the mining method used, backfill provides a working surface, stabilizes stope and pillar walls, as well as the surrounding rock mass, and controls caving of stope backs. There are several benefits associated with the replacement of Portland cement in backfill, including reductions in (i) the footprint by placement of slag waste underground, (ii) the environmental effects and long term liability resulting from disposal and containment of slag waste on surface such as acid rock drainage, (iii) GHG as a result of reduced Portland cement usage (the production of 1 ton of Portland cement produces 1 ton of GHG), and (iv) the significant costs associated with reduced Portland cement usage.

May 1, 2010

By David O. DeGagné

While mine backfill plants are becoming increasingly more automated and instrumented, especially with paste fill operations, underground backfill distribution systems have hardly changed over the years. While fill properties are appropriately measured in the preparation plants, as backfill enters the mine borehole, the technology for control, data gathering and reporting is somewhat lacking. Mines typically experience problems with borehole and pipeline plugging, pipeline bursting, bulkhead failure and exposed fill sloughing. With adequate instrumentation of the backfill system it is possible to obtain a complete, continuous and detailed picture of the entire filling operation from preparation to post-pour. Good data will, over time, provide the basis for needed improvements of backfill systems and will be essential to safer, more efficient and less costly fill practices. This paper will review the areas of the filling operations where monitoring would prove critical to eliminate failures such as pipelines, bulkheads, fill exposures, stope walls, etc. The types of monitoring systems currently available will be reviewed and potential areas for development will be highlighted.

May 1, 2001

By J. Andrew Cornier, Mike Cooper

"Upon successful completion of the AG/SAG Mill project (Cooper et al., 2001) the Brunswick Mine concentrator was configured with single line processing through the AG/SAG mill, followed by two parallel ball mill and flotation circuits. The Stage Grinding project was undertaken to utilize a pre-flotation stage on the AG/SAG mill primary cyclone overflow and simplify the flowsheet by consolidating the two ball mill and flotation circuits, resulting in single line processing fi-om AG/SAG mill to final concentrate. Concurrently, the reclaim water supply capacity was increased to enable flotation cleaning at lower percent solids.Benefits from the Stage Grinding project include revenue enhancement from increased zinc grade and recovery combined with additional lead recovery. Further benefits included a reduction in the number of process pumps, reduction in loss associated with spillage to sumps and process simplification through efficient use of equipment layout.The Stage Grinding project was implemented in six phases over a period of seven months in 2000. Each phase was commissioned during scheduled concentrator shopdays with minimal additional downtime required. One year after project approval the Stage Grinding project was completed at a total cost of $1 1.8 million.INTRODUCTIONThe Noranda Inc. Brunswick Mine, located near Bathurst, New Brunswick, is one of the world’s largest leadzinc mines. Milling of ore began in 1964 from the No. 12 orebody, with an expansion in 1966 to accommodate ore fkom the No. 6 open pit located several kilometers away. In 1980 the pit was exhausted and the concentrator rationalized to accept a design feed rate of 10,500 tomes per day from the No. 12 mine. In excess of 100 million tomes have been milled to date, representing over three-quarters of the known reserve. The concentrator employs differential froth flotation to produce lead, zinc, copper and leauzinc bulk concentrates. The ore is massive sulphide, with approximately 20% valuable minerals, 60% pyrite and 20% silicates."

Jan 1, 2002

By Filip Rochette, Yvan De Busscher

Extraction of minerals can be achieved by a variety of technologies; one of them is ion exchange. There are several ion exchange configurations and mechanical set-ups available, but only one technology will provide more process performance and flexibility compared to the other. The multiple column Continuous Countercurrent Ion Exchange (CCIX) technology provides the highest form of process flexibility with also the highest mineral recovery feasible through ion exchange. In comparison with a fixed bed system, the PuriTech CCIX system offers the benefits of continuous counter-current contact mode. This way the resin capacity is fully exploited leading to reduction in resin inventory and, at the same time, in chemicals and water consumption, and product dilution. For any set of operating conditions the mass transfer zone has a characteristic length (MTZL). The MTZL can be expressed in duration, column length, or volume, but is the measure of the quantity of resin in the system that is doing "work" at any given moment in the process. The objective of continuous ion exchange processing is to eliminate all resin volume from the process equipment that is not within a mass transfer zone. In most commercial ion exchange processes for the recovery of metals, CCIX engineering can eliminate as much as 20 - 80 % of the ion exchange resin inventory. Consumptions of water and chemicals are typically brought down around 40% or more. For each type of resin the selectivity/affinity towards a particular metal depends on the basic process conditions such as pH, concentrations of other competing metals in solution. By changing the pH in the ion exchange process phase, the selectivity of the resin can be changed. By doing this, a split elution, or extraction of metals separately can be achieved and the effect of other competing metals (cross-contamination) can be reduced. For example the DOW resin XUS43578 is commonly used for the recovery of copper or nickel/cobalt separation.

Jan 1, 2016

By Louise Pearce

?Environmental and social impact assessments (ESIAs) are: ??process-driven and scientific processes ??The process entails a number of steps and procedures which result in obtaining a licenceto operate ?and moving more towards a social license to cooperate. ?However, the primary premise of ESIA is to facilitate the consideration of environment and the communities in planning and decision-making which would ultimately make it possible to arrive at decisions that are ?sustainable?. ?Hence, ensuring the development of the mining sector on a sustainable basis is a critical challenge that needs to be addressed by the global community.

May 1, 2011

By K. H. Kretzschmar, M. A. Smith

A brief review of the rapid growth of ACT in Western Canada is presented. It is remarked that this rap-id growth has been accompanied by a heterogeneous approach to design. A more rational and consistent approach is suggested, together with the assumptions on which this approach is based. The operating history of some existing installations is discussed briefly, and conditions necessary for the continued growth of ACT are outlined.

Jan 1, 1960

By Sunil Koppalkar, Guillaume Noel, Ahmed Bouajila, Makni Sami, Claude Gagnon

"Gold gravity recovery circuits utilizing enhanced gravity separators have become an integral part of many of the modern gold processing plants. Thus, efforts to improve the operating efficiency have been a topic of interest for metallurgists for many years. As part of this endeavour, a methodology to estimate the portion of gold in the ore that could be recovered by gravity separation (gravity recoverable gold or GRG) was developed at McGill University. It has been reported in the literature that the gold content estimated with this methodology is the theoretical maximum that is available for gravity recovery that could only be approached but never achieved. A comparison of GRG recovery obtained in the laboratory with the actual recovery in the plant shows that plants recover between one-third to two-thirds of the value predicted by the laboratory test.Research conducted at COREM shows that particle shape transformation during grinding is a major cause of the discrepancy (even though the bleed percent processed, the quality of cyclone classification and the operating conditions of the gravity separator also contribute to the difference). To analyze the gold particle shapes and their deportment, samples were collected from different streams of a grinding-gravity circuit in a gold plant and compared to a concentrate sample from the standard GRG test. A particle characterization methodology based on gold morphology was developed. GRG mapping in a conventional grinding-gravity circuit and the transformation of GRG into non-GRG, as mainly explained by gold particle reshaping, will be discussed. The knowledge gained from the shape analysis will be used to develop shape distributions and partition curves for the classification of shapes.INTRODUCTIONGravity concentration using centrifugal concentrators has gained increasing popularity since the invention of the enhanced gravity concentrators in the nineteen eighties. Among these, the semicontinuous centrifugal gravity concentrators are most commonly used for recovering gold and platinum group minerals (PGM) from grinding circuit streams. The benefits of gold gravity recovery are now well understood and the acceptance by the mining industry is overwhelming. The occurrence of reasonable amounts of gravity recoverable gold (GRG) in an ore prompts gold mills to install gravity circuits. Thus, the increased use of gravity concentration has necessitated a better understanding of the behavior of gold in grinding circuits and of the factors affecting the performance of the gravity concentrator (Laplante et al., 1995). Due to its high density (19.3 g/cm3 when pure) and malleability properties, gold tends to accumulate in circulating streams making it attractive for gravity recovery. The gravity recovery units are typically installed on a bleed stream of the cyclone underflow, mill discharge or cyclone feed."

Jan 1, 2011

By Jeffrey L. Pagnutti

Train derailment can lead to loss of capital, damage to the environment, and loss of life. Machinery condition monitoring techniques can be used to develop a structural health monitoring system for railway track to detect faults at the incipient stage, before catastrophic failure occurs. This study uses vibration measurements from a novel material haulage unit to develop a decision support system for railway track maintenance. A variety of feature sets and classifiers were compared to determine the optimal configuration for fault detection. The results highlight the shortcomings and advantages of certain methods and describe the process in which the optimal result was obtained. The Parzen data descriptor paired with a refined statistical feature set performed the task of fault detection with less than five percent false positive and false negative classification error. Overall, the outcome of these experiments indicated that condition monitoring of railway systems is a promising approach for fault detection and has the potential to avoid catastrophic failure.

May 1, 2013

By D. Bois, P. Keating, J. Lemieux, M. A. Vallée, M. Allard, R. S. Smith, L. Z. Cheng, M. Chouteau, D. K. Fountain

"As part of a larger research program, a number of MEGATEM airborne electromagnetic (EM) test flights were flown over the Gallen massive sulfide deposit in northwest Québec. A particularity of this test site is that a major part of the ore body was extracted before the MEGATEM survey. Therefore one of the purposes of this study was to verify the ability of the system to detect the remaining massive sulfides below the water in the open pit. The open pit is also surrounded by a metallic fence, and a power line is present in the vicinity. A large part of the case study involved accounting for the impact of infrastructure and acidic water on the survey, which will help in the interpretation of airborne EM responses in complex exploration situations.The Gallen deposit was also previously flown with the INPUT and GEOTEM airborne EM systems before the major exploitation period. A comparison between the results from the different survey results allows estimation of the physical properties of the Gallen deposit, which is a relatively poor conductor.A new method for removing the power line signal shows amplitudes with a smaller residual associated with the emanating fields, and more compact, cleaner responses associated with induced currents. This will make it easier to identify bedrock conductors close to power lines"

Jan 1, 2007