Search Documents

By J. P. Mogan, E. D. Dainty, A. Lawson

"The toxicity reduction of emissions from two diesel engines by the emulsification of water into fuel oil was investigated to determine the applicability of such systems to underground mining machinery. . The engines studied were: 1) the Deut; F6L7J4, four-stroke, air-cooled, 6-cylinder, V-configuration, indirect-injection (IDl) engine, and 2) the Detroit Deisel Allison Division 8V7JN, two-stroke, water-cooled, 8-cylinder, V-configuration, direct-injection (Dl) engine.The application of emulsified fuel treatment to the two-stroke engine did not prove to be practicable. In the case of the Deutz engine, however, substantial benefit resulted. For a modest J5 per cent water content in the fuel and an injection timing of24° BTDC, approximate reductions of40 per cent in the concentrations of both particulate matter and nitric oxide (NO) were produced. These reductions were accompanied by insignificant changes in other toxic constituents. The net result was an approximate 30 per cent reduction in the over-all exhaust toxicity for typical LHD operation as assessed by the Health Effects Index criterion. This toxicity reduction represents a significant advance from the points of view of an improved underground environment and/or reduced ventilation costs."

Jan 1, 1981

By Glenn Lyle

CEMI Introduction ? Introduction of the CAF VOD Project ? Who are our partners ? What were the Outcomes What is next

May 1, 2011

By A. E. Soregaroli, H. D. Meade

"The Keystone porphyry molybdenum deposit, located in southcentral British Columbia, is hosted by intrusive rocks of the Cretaceous Mount Lytton batholith and the early Tertiary Keystone quartz diorite stock. The molybdenite mineralization is associated with rhyolite porphyry dikes flanking a large 1300 m by 2100 m breccia complex. Recognition of the potential for the buried molybdenum porphyry system was based on quartz-molybdenite vein fragments within the hydrothermal breccias.The full extent of the molybdenum mineralization is not known. The few deep drill holes along one comer of the breccia complex defines strong metal zoning of molybdenum and associated elements of F, Mn, Zn, Pb, Au, Ag, Fe and W about the molybdenum stockwork mineralization that may be useful for guiding additional exploration. The best mineralization occurred near the base of the deepest drill hole with 0.114% Mo in rhyolite porphyry near the edge of the breccia pipe at a depth of 1350 m.The exploration history of the deposit has been complex, focussing on both porphyry-style mineralization and precious metal veins and stockworks on the periphery of the porphyry system. Exploration to date has defined an attractive porphyry molybdenum system with uneconomic grades at great depth; however, there remains significant potential to define economic mineralization elsewhere in the Keystone porphyry system and adjoining occu""ences."

Jan 1, 1995

By J. A. McLennan, J. M. Ortiz

Nickel laterite deposits are typically formed from tropically weathered mafic-to-ultramafic complexes. The resulting nickel concentration is found within soil horizons and is mineable with regular dozer units. At the time of mining, digging elevations are needed at selective mining units (SMUs) or representative dozer regions (RDRs). Moreover, for mine planning, the costs due to dilution and lost ore require mining elevations to be specified. A conditional simulation approach is used to calculate “optimum” RDR mining elevations. Multiple realizations of the ore base surface are simulated. For a single bottom surface realization, dilution and lost ore costs are calculated over the entire vertical extent of each RDR. The optimum mining elevation is the elevation where the lowest summed cost of “accepting dilution” and “wasting ore” occurs. The reported RDR dilution is the cost of mining the volume of waste located below the bottom surface and above the optimum mining elevation. The reported RDR lost ore is the cost of not mining the volume of ore above the bottom surface and below the optimum mining elevation. For all ore bottom surface realizations, optimum RDR mining elevations and their associated dilution and lost ore costs are calculated and compiled to represent production uncertainty.

Jan 1, 2006

By H. Reimer

The rates of return on investment are examined for several major Canadian mining companies. Because we are dealing with a highly cyclical industry, subjected to widely fluctuating metal prices, rates of return are examined over a 20-year period. Conveniently, the first decade examined reflects the period when the industry enjoyed incentives to develop deposits; during the second decade, incentives were reduced and the industry became the most heavily taxed industry in Canada. The high rates of inflation since 1973 have distorted the real rates of return on investment if one considers replacement cost.

Jan 1, 1977

By M. Y. Solar, W. G. Davenport

Most of the recent growth in nickel demand has been for the production of stainless steels and virtually all of it has been satisfied by new ferronickel and nickel pig iron projects. But "good" laterite resources are more and more difficult to find: Ni grades are decreasing while Fe contents are increasing and SiO2/MgO ratios vary from 1 to 3 and even higher if limonites are included. Predicting the smelting behaviour of such ores requires a more fundamental understanding of the thermodynamics of these systems in commercial operations. One valid question is thus whether these furnaces are at thermodynamic equilibrium or not. The present paper investigates this question, compares calculated and measured O2 partial pressures and mechanical/chemical slag loss ratios and concludes that ferronickel furnaces are not at thermodynamic equilibrium. This departure from expectation is actually to the operators’ advantage: the targeted ferronickel grades can be obtained at lower reduction potentials than calculated from pure thermodynamics.

Jan 1, 2014

By W. L. Ott, J. E. Hawley, C. L. Lewis

"IntroductionTHE APPLICATION of spectrochemical analysis to metals of the platinum group was advocated by Harvey (3) as follows: ""The spectra of the platinum group metals have been studied less than many of the more common metals. The rarity of occurrence of these elements makes the analysis relatively unusual. Potentially, the analysis of this group is an excellent application of spectrographic methods, particularly in contrast to the tedious chemical procedure"".Wichers (8) divides platinum-metal analysis into three broad divisions as follows :( 1) The detection and estimation of these metals in other materials, e.g., ores, where the amounts present are very small.(2) The detection and estimation of impurities in the refined metals themselves ....(3) The analysis of alloys of the platinum metals .....The present paper deals with the second division: analysis of refined rhodium.Research on spectrochemical techniques for determination of trace contaminants in refined platinum metals was begun at Queen's University in 1949, under the supervision of Professor J. E. Hawley. Since 1953, the work has been continued in the Metallurgical Laboratories of Falconbridge Nickel Mines, Limited. Techniques for spectrochemical analysis of refined platinum and palladium have been published ( 4, 5). A technique for analysis of refined iridium has been developed but not yet published."

Jan 1, 1955

By L. W. T. Weitzel

"This paper reviews the Falconbridge- SMRQ’s Raglan project in northern Quebec and the process that was used in developing its current long-term mine plan. Challenges were many and not only limited to the longevity of the project, numerous ore deposits (both underground and open pit), and a 40 km property strike length. As a result of its remote northern location, other factors such as progressive reclamation, leachable mine waste, water treatment, and waste management were also part of the plan. A combination of modern planning tools were used to formulate the plan including DataMine, Mine 2-4D, AutoMod Simulation, and an Excel-based financial spreadsheet to bring the total plan together. The focus of the paper is to show the complexity of modern mine planning and associated economic modelling of mine processes. IntroductionThe Raglan project is located 1660 km directly north of Quebec at the northern tip of the Quebec Peninsula in Nunavik. The main property is 40 km in length stretching from the Donaldson airport area at the eastern edge of the property to East Lake at the western edge. The Deception Bay port is 90 km north of the main complex/mill situated at Katinniq which lies approximately in the middle of the property (Fig. 1). The mine processes 1 000 000 tpy of ore from both open pit and underground sources. The mill is forecasted this year to produce more than 150 000 t of concentrate grading more than 18% nickel. All personnel and critical cargo are transported to the site via a company-leased 737 jet from Rouyn-Noranda where the main administration office is located. The majority of cargo is shipped to the site via Deception Bay from Quebec and on the return trip, nickel concentrate is shipped back. From Quebec, the nickel concentrate is sent by rail to the Falconbridge smelter in Sudbury and on the reverse rail haul, nickel matte from the smelter is sent to Norway via Quebec."

Jan 1, 2003

By Phillip I. Merritt

"IntroductionDuring and since• the war, it has been my privilege to work closely with those in Canada who are responsible for the vital raw materials needed in our co-operative atomic energy programme. The understanding which has developed between our two groups in this all-important enterprise has been a great source of pleasure. We in the United States are aware of the importance of the contribution made by Canada to this project, and we look forward to continuing our mutually advantageous relationship.The impact of World War II, and the decision by Canada, Great Britain, and the United States to join in a programme for the development of atomic weapons, created a sudden and immense demand for uranium minerals. Early in the raw materials programme, it was evident that sufficient raw materials to fulfill war-time atomic weapon requirements could be secured from three sources: the rich pitchblende deposits of the Eldorado , mine at Great Bear lake; the Shinkolobwe mine in the Belgian Congo; and as a by-product of the vanadium industry of the Colorado Plateau in the United States. In the early part of the programme, therefore, our joint efforts were directed toward obtaining immediate maximum production from these localities. The contribution made by Eldorado Mining and Refining (1944), Limited, both in supplying and refining raw materials, was and continues to be of vital importance.In addition, it was also obvious from the first that in this programme, as in any mining enterprise, exploration activities directed•toward the discovery and development of new sources of uranium ore were essential if production were to be maintained over an extended period of time. In order to satisfy obvious security requirements during the war, it was necessary to proceed with this exploration programme, both in Canada and the United States, as secretly as possible. With the end of the war, and the revelation that an atomic weapon had been developed, however, secrecy in exploration was no longer required. The important thing was to get on with a broadened exploration programme."

Jan 1, 1950

By Dany Pelletier, Yeves Breau, Ahmed Bouajila, Claude Gagnon

"In flotation circuits, direct measurement of the volumetric flow rate delivered by electromagnetic flowmeters is often difficult to obtain particularly due to piping and flow constraints. However, on-line material balance calculation could offer a reliable alternative to flow rate sensing. This paper describes an on-line material balance software package as applied to a copper flotation circuit for mass flow rate estimation mainly based on the output of an x-ray fluorescence onstream analyser. Rule-based procedures for the management of the main calculation modules are designed and integrated to a Comdale expert system. Attempts to diagnose the flotation process from mass flow rate data are also discussed.INTRODUCTIONThe need for improved process diagnosis, control and optimisation has become more evident for the mineral processing industry in the last decade. Therefore, new process variables need to be inferred or measured particularly in highly multivariable processes such as flotation. This process is subject to a wide variety of disturbances mainly generated by frequent and sometimes abrupt changes in physical and chemical characteristics of the ore and due to some irregularities in manual process operating procedures.A flotation circuit scheme is always a complex network counting more than two dozens of slurry streams. Information about those streams (%solids, metal content analysis, and flow rates) are important for process diagnosis, performance evaluation control and optimization (1,3).On-line sensing instruments such as x-ray fluorescence (XRF) on-stream analysers (OSA), gamma density gauges and electromagnetic flowmeters have been developed for the measurement of those variables. Unlike the other variables, stream flow rates could be determined by different ways:"

Jan 1, 2000

By Mark G. Lafontaine

Underground 802.11 wireless communications has become widely adopted for automation and communication purposes but maximizing the wireless signal presents many obstacles given the harsh environment as well as the presence of materials and conditions that can reduce signal propagation. Changes in elevations and curvatures in ramp to drift transitions also affect the wireless signal. Based on the requirements of wireless applications such as voice, data, or location tracking, the wireless site survey is the key tool for measuring and predicting signal strength and signal-to-noise ratio. These readings help determine the maximum distance between access points in order to sustain an overlapping wireless signal where required. This paper describes the methodology and tools used for measuring 802.11 wireless signal strength in an underground mine environment in Northern Ontario. The physical characteristics of the mine and the actual recorded wireless signal data will be presented in order for the audience to gain an understanding of the factors that affect signal throughput. Antenna selection used for the site survey will also be discussed as it played a key role in propagating the wireless signal.

May 1, 2013

By R. D. Brown

"AbstractIn order to raise the enormous amounts of capital which will be essential for the development of Canada's mineral and petroleum resources, this country's resource industry must be permitted to earn an acceptable rate of return. The existing tax regime, with its high rates, complexities and misdirected incentives, presents a serious obstacle to our resource industries in their development of Canada's immense , but increasingly lean, resources. Government tax and other policies are not the only cause of the crisis now facing the resource sector in Canada, but a reformed tax system, with stable and reasonable tax burdens, is required if Canada's resources of minerals, oil and natural gas are to continue to contribute in the future, as in the past, to our national well-being.An independent task force, organized under the auspices of the Canada West Foundation, has recently completed a wide -ranging report: on the future development of Canada's mineral, oil and gas resources. This five-volume report, completed after almost two years of research and study, concludes that Canada •is facing a major crisis •in the development of our resources, It states that unless corrective action is taken now, mineral production and exports could decline drastically after 1985, at the same time that Canada would face massive bills for imported oil because of inadequate and declining production.The task force, chaired by the author of this article, has put forward recommendations for a fundamental shift in both federal and provincial policies in order that Canada's mineral reserves can be developed in the national interest. This article consists of excerpts from the summary of the task force's report."

Jan 1, 1977

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 Tony Moore, Peter Riccio

"MMG (Minerals and Metals Group) operates the LXML Sepon’s mineral processing facility located 40 kilometers north of the town of Sepon, in the Savannakhet Province, Lao PDR. The Sepon copper plant produces 70,000 tons/year of LME grade A copper cathode using leachautoclave- SX/EW-flotation technology (Baxter et al., 2003). Pyrite recovery in the flotation circuit is critical to the operation, as it is used to generate acid and soluble ferric ion for the leach circuit. Low pyrite recovery has been an on-going challenge in the flotation circuit. Final tailings characterization work done by Ian Wark Research Institute (Bassell et al., 2006) showed that the pyrite losses to the tailings are made up of a combination of coarse liberated particles and finer particles that have been coated by clay fines.In December of 2005, a joint Cytec-MMG technical program was initiated to address the pyrite recovery issue. A series of diagnostic tests were performed in the Cytec Stamford Research Facility using synthetic plant water showing that the collector was precipitating as a metal salt and was unavailable for mineral attachment. The tests also identified several collector chemistries that would likely be robust in the low pH (< 1), high dissolved metal ion environment and will not complex with metal ions in solution. With the support of the Sepon on-site engineers, an extensive, successful laboratory program was completed, which was subsequently followed by on-plant testing that showed a step wise improvement in pyrite recovery.INTRODUCTIONLow pyrite recovery has been an ongoing problem in the flotation circuit at Sepon. Sulfur recovery (indirect measure of pyrite) was improved from 40% to 65%-75% in mid-2005 when on site laboratory work confirmed that AERO® 8045 Promoter was a more effective collector then AERO® 407 Promoter. However, sulfur recoveries above 65% could never be achieved. Sepon requested the Ian Wark Research Institute to complete a surface analysis study using Scanning Electron Microscopy, X-ray Photoelectron Spectroscopy, and Time-of-Flight Secondary Ion Mass Spectroscopy to determine if clay coated pyrite played a role. It was concluded that the pyrite losses to the tailings are made up of a combination of coarse (+ 100µm) liberated particles and finer (-74µm) particles that have been coated by clay fines. The majority of the losses appear to be due to the former. In December of 2005, a series of diagnostic tests were performed in Stamford using synthetic plant water in order to identify what chemistries would likely be robust in the slimy low pH and high dissolved metal ion solution environment. Results showed that several chemistries would not complex with ferric, ferrous or copper in solution and therefore should perform well in the Sepon flotation. The incumbent collector, AERO® 8045 Promoter was complexing with metal ions in solution. This resulted in the collector not being available for adsorption onto pyrite."

Jan 1, 2011

By Alan M. Jessop

This paper discusses the distribution of frozen ground in the zone of discontinuous permafrost in relation to the pattern of surface temperature. The importance of understanding permafrost in relation to surface construction and open-pit mining operations is stressed.

Jan 1, 1972

By T. Banerjee, D. Felsher, G. Leavoy

"Lake Shore Gold is engaged in commercial gold production at both the Timmins West and Bell Creek mines, located in Timmins, Ontario. Run of mine ore is processed at the Bell Creek mill which consists of a conventional gold mill flow sheet involving crushing, grinding, gravity concentration and carbon-in-leach (CIL) for gold recovery. Since 2009, the operating capacity of the mill has been upgraded from 2000 tpd tonnes per day (tpd) to over 3,000 tpd. The most recent expansion involved the installation of a low aspect ratio SAG mill to replace the secondary crusher. Without operational data on the low aspect mill, combined with a site team that was new to SAG milling, there were many challenges in achieving the target throughput from the circuit. Through the implementation of AwaRE advanced controllers, running in closed loop with PRC fragmentation cameras as well as embedded PARC modules within the Allen Bradley PLC, the site was able to rapidly develop a best operating practise and has been successful in creating a stable and consistent operational environment. The process, lessons learned and eventual solution will be reviewed in this paper.INTRODUCTIONLake Shore Gold is engaged in commercial gold production at both the Timmins West and Bell Creek mines, located in Timmins, Ontario. Run of mine ore is processed at the Bell Creek mill which consists of a conventional gold mill flow sheet involving crushing, grinding, gravity concentration and carbon-in-leach (CIL) for gold recovery. Since 2009, the operating capacity of the mill has been upgraded from 2,000 tpd tonnes per day (tpd) to 3,150 tpd. The most recent expansion involved the installation of a low aspect ratio SAG mill to replace the secondary crusher. This endeavor was split into two phases: the expansion of the back-end (Phase 1) and the front-end (Phase 2) of the mill. Phase 1 of the expansion was completed at the end of 2012 and involved enhancements and capacity addition to the leaching and adsorption circuits, which increased the mill’s capacity to 2,500 tpd. Phase 2 of the expansion commenced at the end of July 2013 and involved the expansion of the crushing and grinding circuits. The expanded front-end of the mill now has a capacity of 5,500 tpd, and processes ore from both Bell Creek and Timmins West mines. The updated flow-sheet, as shown in Figure 1, illustrates the replacement of the two-stage crushing and ball milling circuit with a single stage crusher and a low aspect ratio SAG mill."

Jan 1, 2015

By Adrian Daniel

"Dating back to 1934, Con Mine is located directly south to the city of Yellowknife in the NWT, Canada. With mill operations ceasing in 2004, a challenging surface remediation situation resulted which required the treatment of close to 40,000 m3 of Arsenic impacted material.Through much of the period of 1941 to 1970, Con Mine treated their refractory arsenopyrite ore through the use of an Edwards Heath roaster. With mounting environmental pressure and through Canadian governmental studies during 1950 to 1970, attention was directed to the Arsenic Trioxide material being collected by two Doyle scrubbers on the Con’s roaster stack. In 1970, the roaster was decommissioned leaving the resulting Arsenic material in two containment areas on surface.As a result of Con Mine entering into remediation in 2004, the Con’s autoclave, commissioned in 1992, was dedicated to the immobilization of high impacted Arsenic material through the combination of excess Iron under high temperature and oxygen overpressure. Examined, herein, is the history and chemistry of the Con Mine autoclave as well as the two stages of chemistry for the Water Treatment Plant used to remove arsenic, heavy metals and WAD cyanide from tailings water. Simplified capping plans of the tailing containment areas and a high arsenic impacted area are also presented.INTRODUCTION TO CON MINECon Mine (Con) is situated just south of the City of Yellowknife in the North West Territories (NWT) Canada and is bounded locally by Yellowknife Bay (North Extension of Great Slave Lake) to the east and Kam Lake to the west (Figure 6). The discovery of gold at Con was made in 1934 and mineral rights were acquired by Consolidated Mining and Smelting Limited (Cominco) and Falconbridge soon thereafter. Nerco Minerals Limited (Nerco) took control in 1986 and in 1993, was subsequently sold to, Miramar Mining Corporation which in turn was purchased by friendly takeover involving Newmont Mining in November 2007 as a result of acquiring the Miramar’s Hope Bay project. Con’s underground operations ceased in September 2003 and have since entered into the remediation of the site. The current surface lease holdings are about 340 Hectares (Table 1) which sits on top of the Archean-aged Yellowknife Greenstone Belt."

Jan 1, 2009

By R. Agius, A. Nacu

"Adoption of the International Cyanide Management Code, regulatory requirements and community concerns have increased the need to implement suitable cyanide destruction processes at gold operations to meet ever more stringent discharge limits. As standards set for the allowable concentrations of cyanide, cyanide compounds and other contaminants may vary from country to country, jurisdiction to jurisdiction, and even from site to site, there is no “one size fits all” technological solution. Currently the most common cyanide destruction processes used in industry are sulfur dioxide/oxygen, hydrogen peroxide and Caro’s acid. Regardless of the process used, cyanide destruction plants must be reliable and achieve permit guidelines at all times. The selection of the most appropriate cyanide destruction process for an operation depends on several factors, including permit discharge requirements, tailings chemistry, location, site-specific climatic conditions and size of the operation. Only after considering all these factors together can the most effective approach be selected to achieve the permit guidelines economically and technically feasible. Finally performing the correct test work program is the most important step to ensure that the correct process design criteria can be determined to accurately calculate capital and operating costs.IntroductionThe adoption of the International Cyanide Management Code in 2005, stricter regulatory requirements and community concerns prompted by environmental incidents involving cyanide have increased the need to implement cyanide destruction processes at gold and silver operations.Process solutions associated with the extraction of gold and silver contain several forms of cyanide. The most toxic form of cyanide is free cyanide, which can be present as a dissociated cyanide anion (CN-) or gaseous or aqueous HCN. Weak or moderately stable cyanide complexes such as those of zinc, copper and nickel are classified as weak acid dissociable (CNWAD). Although less toxic than free cyanide, weak acid dissociable cyanide complexes are considered “ecologically sensitive” forms of cyanide and are regulated in most jurisdictions. In practice, reported WAD cyanide values are comprised of both free cyanide and weak acid dissociable cyanide complexes. Cyanide complexes with gold, mercury, cobalt and iron are referred to as strong acid dissociable complexes (CNSAD) and are much more stable even under mildly acidic conditions. Another term commonly used in cyanide chemistry is total cyanide, which represents all cyanide compounds present in solution, with the exception of cobalt complexes. Total cyanide levels in solutions are in most cases higher than WAD cyanide values and the difference between the two usually indicates the presence of iron-cyanide compounds. Typically, in Canada CNTOTAL levels cannot exceed 1 mg/L in solutions."

Jan 1, 2017

By T. G. Hawkins, T. M. Naciuk

"The Katie Cu-Au deposit is situated in southeastern British Columbia, 425 km east of Vancouver. The deposit is a member of the alkaline group of porphyry Cu-Au deposits associated with potassically and propylitically altered andesitic volcanic rocks.The Katie porphyry system occurs in mafic to intermediate alkaline volcanic rocks of the Lower Jurassic Elise Formation of the Ross/and Group. Host metavolcanic rocks include andesitic to basaltic flows, flow breccia, massive fine tuff and crystal tuff Gabbroic intrusions alternate with the volcanic rocks in drill core. The lack of chilled margins and shear contacts, as well as their similar composition to the volcanic rocks, suggest that the gabbro was synvolcanic.Alteration exhibits a zonal pattern spatially related to zoned porphyry-style mineralization. Propylitic alteration is common and assemblages consist of epidote, chlorite, sericite and calcite. Potassic alteration zones are accompanied by elevated copper-gold grades and are composed of K-feldspar, plagioclase, quartz, biotite and chlorite. Narrow drillhole intervals of secondary magnetite, generally less than 2 m across, occur above the potassic alteration zones. A thick oxidized cap lies above the mineralized zones, although only local supergene enrichment has been identified. The lack of supergene enrichment is perhaps due to intense near-surface fracturing and leaching from a high energy groundwater environment.Sulphide mineralization consists mainly of pyrite within the propylitic halo, and pyrite and chalcopyrite with trace pyrrhotite, sphalerite, tetrahedrite, bornite and molybdenite within the potassic alteration core. Malachite, azurite and traces of chalcocite occur within the oxidized cap.Discovery and exploration techniques have included airborne geophysics, regional stream sediment sampling, prospecting, geological mapping, ground geophysical surveys, soil sampling surveys, and diamond drilling. Two primary targets of porphyry copper-gold mineralization have been identified by exploration. The Main zone strikes northwest, has an apparent true thickness ranging from 70 m to 135 m, and is a minimum of 500 m in length. The 17 zone strikes northwest, has an apparent true thickness of 90 m, and is a minimum of 300 m in length. The two zones are defined by grades that generally exceed 0.2% Cu and 0.25 g/t Au. Both zones are open along strike and to depth."

Jan 1, 1995

By Marc Legault

The Duparquet mining camp situated along the Quebec segment of the Porcupine-Destor Fault was the site of gold exploitation from 1933 to 1956 and 1988 to 1991. Numerous gold showings and deposits straddle the fault. An ongoing regional metallogenic study by the Quebec Geological Survey has identified five main types of gold mineralization, each showing a distinct style, alteration, control, metal content, and timing. In order to maximise the impact of this study, a 3D regional common-earth-model was constructed along a critical segment of the Porcupine-Destor Fault with the gOcad® technology. The realisation of this model required the maximum use of the public SIGEOM numerical database, as well as the recovery of significant private data from exploration company partners. The 3D model is also a powerful new dynamic exploration tool, which can be queried using geological criteria characteristic of the different gold deposit types. This 3D model can be modified and improved continuously by adding data from new drilling, mapping or geophysical surveys. The case of the Porcupine-Destor Fault illustrates the importance of 3D common-earth-modelling in delivering refined technological geological syntheses likely to attract significant investments from the mining exploration industry, especially for deep exploration programs within mature mining camps.

May 1, 2004