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By C. Hilgendorf, J. Gingerich, J. R. Boniwell, M. Drouin, D. David on, J. Boldy

The initial discovery of gold in the Eastmain River area, 310 km northeast of Chibougamau, was made by Placer Development Limited in 1970. This discovery resulted from the drill testing of an airborne E .M. Target located in an area of extensive glacial overburden, within an unexplored Archean greens tone belt considered prospective for base metal deposits. Intermittent exploration by another company between 1973-1977 failed to obtain promising results and the existing claims were allowed to lapse. In 1981, Placer reactivated the project and initiated intensive exploration during the next two years which included aerial E .M. surveys, claim staking, ground E .M. and magnetic surveys, geological mapping, diamond drilling and attendant borehole P,E.M. surveys. Beginning in 1983, exploration has been conducted on a joint venture basis with Eldor Resources Limited, The greenstone belt under investigation has an arcuate distribution pattern relative to a centrally located granitic core. Occurrences of gold mineralization defined to date are located to the south of the granite along a strike length of 7 km, and appear to be restricted to the lowermost of two mafic volcanic cycles. This lower cycle is dominated by basaltic flows with subordinate rhyolitic flows and pyroclas ties. Concordant, variably magnetic, massive to talcose ultramafic units occur towards the stratigraphic top of the lower mafic volcanic cycle and appear to crudely define areas considered prospective for gold on a regional bases. Economic interest in centered on a s tratabound, siliceous, sulphide-bearing unit hosted in a 15- 25 metre thick sequence of rhyolite tuffs, basalts and intercalated ultramafics, The siliceous ore bearing unit ( interpreted as a recrystallized chert) contains from 10%-30% pyrrhotite and pyrite with subordinate chalcopyri te and minor sphaleri te. Alteration is characterized by mica development, silicification and carbonatization. Garnets are also occasionally present in close proximity to the ore horizon. The sequence is south facing, and overturned to the northeast at 35°-55°. Explora tory drilling in the vicinity of two conductive targets has been on 100 metre centres along a 1 km strike length of the prospective sequence. To the end of 1983, two ore zones (A and B) have been partially drill tested with estimated indicated and inferred geological reserves of 1 million tonnes grading 11.7 g/t gold , 14.7 g/t silver and 0.26% copper. The system is open at depth. This discovery is the result of the effective integration of geophysics and geology with contributions by many over a long period of time. Key events that can be emphasized are: ( 1) initial area selection of a remote greenstone belt in 1969 - albeit for base metal deposits , (2) utilization of an airborne E .M. system which successfully targeted the A Zone in 1970 , (3) the timely reactivation of the project in 1981 and the subsequent recognition that the original discovery represented a sulphide bearing stratabound horizon with implicit volcanogenic connotations , (4) the intensive effort in 1982-83 deploying aerial and ground geophysics coupled to volcanogenic concepts of ore distribution which resulted in the discovery of the B and C Zones in 1982, and (5) the integration of downhole P . E.M. surveys and geology to successfully delineate ore at increasing depths . To the end of 1983 , $2.6 million has been expended, and it is hoped that continued effort will result in the eventual delineation of an economically viable ore deposit for the joint venture partners .

Jan 1, 1984

By K. V. Lindell

Introduction This paper describes a recent innovation in the design and construction of mine headframes. A reinforced concrete headframe was built by using sliding forms. A concrete headframe of conventional design was originally considered, but investigation of this project showed that it was doubtful if the bearing strength of the soil was sufficient to support the great weight of a structure of this type. In addition, the slope and the fractured condition of the serpentine bed-rock did not permit satisfactory piling. A conventional steel headframe with storage bins was then designed, but, due to the steel situation, delivery promises were set back many months. The concrete headframe was again investigated, and a design was adopted incorporating a circular headframe lower in height than that first considered, with skips discharging into a smaller surge bin. The upper section of the shaft collar was strengthened to result in a stable structure which would be supported by bed-rock, as well as by the concrete and steel lining of the shaft itself.

Jan 1, 1948

By George P. Demopoulos

For more than 20 years the author had the privilege of working closely on a number of R&D projects with Lucy Rosato and her team at CEZinc. Several of these projects were driven from the sustainability agenda that Lucy Rosato championed as an innovation leader that supported research collaborations. Highlights from this highly rewarding collaboration are to be presented in this paper. In particular we will deal with the following works-topics: (a) iron control via solvent extraction as alternative to jarosite precipitation; (b) production of high-density gypsum by controlled neutralization of simulated zinc plant process/waste waters; (c) selenium removal from weak acid solutions; (d) electrolyte purification by cementation; and (e) manganese control by oxidative precipitation with SO2/O2.

Jan 1, 2015

By W. Rostoker

Packing Experiments The porosity and most of the other physical properties of a coherent mass of any material built up by the packing together of discrete particles will obviously vary with, and be governed by, the manner of association of the particles. The relation of packing to powder metallurgy has been discussed in some detail by at least two authors. Packing Theory Theories of particle packing have been put forward by C. C. Furnas and A. E. R. Westman. Although their approach to the problem is not the same, their conclusions are similar. In the process of packing, they visualize the voids of a uniformly sized material becoming filled with particles of a smaller size, and the voids between these being filled in turn with still finer particles. Obviously, if this process is carried ad infinitum, the resultant mass will have the same density as the constituent particles. In practice, of course, such a density of packing is never attained. In addition, the premise is made that successive particle sizes must fit into the voids left by the immediately larger particles- an assumption requiring definite size gradations and also particle shapes. It remained, then, for theory to correlate relative diameter ratios, and proportions and numbers of sizes of particles, for requisite packed densities. Briefly, the following principles were postulated: (a) For an infinite diameter ratio between largest and smallest sizes, an infinite number of particle sizes in proper proportion is required to give natural density. (b) For a given diameter ratio, there is a maximum number of permissible particle sizes for maximum packed density (Furnas). (c) Provided the particle shape is spherical, or approximately so, the proportions o particle sizes can be calculated. (d) The ratios of successive diameters of particles are in geometric progression.

Jan 1, 1947

By H. L. Snyder

This paper outlines the approach to the underground construction work involved in the Churchill Falls Power Project. It is the first in a series of papers which CIM Bulletin plans to publish as the different 11hases of this large-scale operation evolve.

Jan 1, 1968

By Limao Zhang

This paper presents a BIM-based Risk Identification Expert System (B-RIES) for metro construction, composed of three main built-in subsystems: BIM extraction, knowledge base management, and risk identification subsystems. The engineering parameter information related to risk factors is extracted from the BIM of a specific project where the IFC standard plays a bridge role between the BIM data and metro construction safety risks. An integrated knowledge base, consisting of fact base, rule base and case base, is established to systematize the fragmented explicit and tacit knowledge. A hybrid inference approach, with case-based reasoning and rule-based reasoning included, is developed to improve the flexibility and comprehensiveness of the system reasoning capacity. During the safety risk identification process, B-RIES is able to improve the inefficiencies in engineering information extraction, reduce the dependence on domain experts, and facilitate knowledge sharing and communication among dispersed clients and domain experts. A typical safety hazard identification in the Mingdu station, located in the Wuhan Metro Line Two, is presented in a case study. The results demonstrate the feasibility of B-RIES, and its application potential. B-RIES can be used as a decision support tool to provide guidelines for safety management in metro construction, and thus increase the likelihood of a successful project in a complex environment.

Aug 1, 2013

By V. Panayotov, M. Panayotova, R. Villas-Bôas

The "United Nations Framework Classification (UNFC-2009) for Fossil Energy and Mineral Resources 2009” is the international system designed to meet (to the extent possible) the needs and to support the decision making and resources management of private industry investment, governments, policymakers, bank investment, scientists. There are different international and national systems classifying commodities (resources, reserves, possibility and feasibility to extract them, etc.) with their own definitions and reporting terminology which often do not overlap entirely or even differ significantly - thus creating difficulties and problems among stakeholders to understand each other. The UNFC-2009 is developed to allow “speaking in one language”. The paper presents briefly the UNFC-2009. The UNFC-2009 applies simultaneously three fundamental criteria to classify projects: economic and social viability, field project status and feasibility, and geological knowledge (so called E, F and G axes), thus creating a visualized, easily understandable three dimensional system. The E, F and G axis categories are divided to subcategories, using additional criteria. The UNFC-2009 is already applicable to solid minerals, nuclear fuel resources, petroleum. The amounts of solid waste generated by metals production from ores (mining, minerals beneficiation, extraction metallurgy) and its metals content are discussed from the viewpoint of using the waste as resource. An attempt is made to apply the UNFC-2009 to technogenic waste from metals production from ores - both to old engineering constructions (historic mining dumps and reclaimed beneficiation tailings ponds) and new (currently in use) dumps and ponds.

Jan 1, 2016

By B. Surender Mohan

Mining lignite pollutes the environment and causes ecological damage if unattended. Being conscious of the importance of environmental resources for the well-being of the living system, the Neyveli Lignite Corporation (NLC) adopts the policy of environmental regeneration as the foundation on which productivity is built. NLC started investing on Eco Care and Environment Protection long ago and it continues. Early investment in environmental protection has resulted in steady growth of the Company along with a healthy environment. The future vision of NLC is to be in the vanguard among the contributors to the community, environment and the nation by developing and utilizing industrial and human resources to the optimum. Untiring efforts are being put in mines (NLC as a whole) to maintain and sustain the ecological balance arising due to continuous mining activity. NLC?s Environmental Management System is becoming a symbolic role model for many of the opencast mines in Southeast Asia. NLC has been bestowed with number of prestigious Environment and Sustainability awards in recognition of the mammoth contribution in maintaining a clean and green environment.

Aug 1, 2013

By D. R. Lentz, C. J. Beaumont-Smith, S. H. Mcclenaghan

"Abstract - The Louvicourt Au-Ag-Cu-Zn-Pb sulfide deposit is hosted by a Middle Ordovician calc-alkaline sequence of aphyric rhyolite flows and associated fragmental rocks at the top of the Flat Landing Brook Formation. The Zr/TiO2 (average = 0.110) and Y/TiO2 (average = 0.021) ratios in the footwall felsic volcanic rocks are consistent with known values for the Reids Brook member. The deposit consists of two concordant lenses of semi-massive to massive sulfides, approximately 150 m long and up to 9 m thick, which represent a fold repetition of a single exhalative horizon. The deposit contains a geologic resource of 136 000 tonnes grading 1.2% Pb, 1.0% Zn, 0.4% Cu, 90.9 g/t Ag, and 0.96 g/t Au; the deposit locally contains elevated Au (2.9 ppm) and Ag (320 ppm) contents. A laterally continuous iron formation that contains barite caps the deposit, and is gradational vertically and laterally into laminated siltstone. The exhalite confirms the stratiform nature of this deposit, but a large percentage of sulfides occur as late replacements of altered felsic fragmental rocks in the footwall. Abundant examples of colloform pyrite and perlitic and spherulitic textures in volcanic clasts are well preserved. The base- and precious-metal content of the Louvicourt deposit is atypical of the Bathurst Mining Camp (BMC). Reported assay data (n = 27) indicate an average Pb/Zn ratio of 2.6, the highest in the BMC (average = 0.39). Lead exhibits a strong Spearman Rank correlation (r' = 0.92) with base metals throughout the sequence, indicating a preponderance of galena in both the stockwork and stratiform zones. The Ag and Au contents in this deposit are among the highest in the BMC and exhibit a Au-Ag- Cu-Pb association. Barite-rich exhalative pyrite exhibits a moderate Au correlation with Ag (r' = 0.77; n = 10) and Cu (r' = 0.76) and occurs in portions of the exhalative sulfides that are enriched in Pb. Chemical exhalative rocks are conformably overlain by trachy-andesitic volcaniclastic (possibly pyroclastic) rocks that are assigned to the Little River Formation. These are enriched in Nb (average = 38.4 ppm) and P2O5 (average = 0.17 wt.%), and have much lower Zr/TiO2 (average = 0.056) and Y/TiO2 (average = 0.0062) relative to rocks higher in the hanging wall. The intermediate volcanic rocks are conformably overlain by massive to pillowed basalt flows and related hyaloclastite that have Nb/Y = 0.60 and high TiO2 contents (average = 2.8 wt.%). This chemistry is consistent with rocks of the Brunswick Mines member (Little River Formation), except that these rocks are considerably enriched in P2O5 (average = 0.82 wt.%). This syngenetic exhalative deposit is unique for the BMC with a high Pb/Zn and elevated Au and Ag contents, as well as an epithermal signature (Sb-Ag-Au-Tl-Hg), analogous to high sulfidation volcanogenic massive sulfide deposits. Its intimate relationship with an emergent felsic dome (Flat Landing Brook Formation), chlorite-silicate-oxide-sulfide exhalite (locally hematitic), and the abundance of barite are classical features of many of the Kuroko deposits."

Jan 1, 2006

By J. D. Clucas, D. B. Dreisinger

"The Starved Acid Leach Technology (SALT) has been developed by Search Minerals to extract nickel and cobalt VALUES (from nickel laterite ores (saprolites) and Caron plant residues. The technology consists of sulfuric acid atmospheric leaching of the ores or residues followed by neutralization and recovery of nickel and cobalt. The acid addition is carefully controlled to maximize nickel and cobalt extraction while minimizing overall consumption of acid by various gangue reactions. The final recovery processes can be tailored for maximum economic benefit. The use of resin-in-pulp processing is advocated as the most cost effective method for initial recovery of nickel and cobalt from lower grade materials. INTRODUCTIONCommercial processes for laterite ore treatment vary according to laterite type and local conditions. The two general categories of laterite ore are saprolites and limonites.Saprolites are generally treated by pyrometallurgical processes for reduction of nickel to matte or ferro nickel alloys. The high cost of drying, chemical reduction and electric furnace smelting requires that the saprolite grade for economic processing is of the order of 1.8% nickel or higher. There are of course large amounts of saprolite that fall below this “cut-off” grade that are not currently economic.Limonites can be treated by the Caron Process which involves drying of the ore, a reduction roast of the whole ore to reduce nickel and cobalt (and some iron) to the metallic state followed by ammonium – ammonium carbonate solution to leach nickel and cobalt. Nickel and cobalt recovery are low (70-85% for Ni and 20-50% for Co). The Caron plant tailings therefore contain high levels of unrecovered nickel and cobalt. Relatively few plants have used the Caron Process and new installations are not anticipated due to the high energy cost of drying and reduction roasting. Nevertheless, plants in Brazil (Niquelandia), Australia (Yabulu) and Cuba continue to operate.The high pressure acid leach (HPAL) process was pioneered at Moa Bay in Cuba in the 1960’s in the treatment of limonites. In the 1990’s the HPAL process was touted to revolutionize the nickel industry with low capital and operating costs for new installations. Murrin Murrin, Cawse and Bulong in Australia were started and in each case the technical difficulties of operating at extreme temperature and pressure conditions and the challenges in “ramping up” a complex hydrometallurgical facility conspired to cause these plants to fail economically. At present, Cawse and Bulong are closed and Murrin Murrin continues to operate after undergoing a financial restructuring."

Jan 1, 2012

By Larry J. Hulbert, Louis J. Cabri, John L. Campbell, Gilles Laflamme, Chris G. Ryan, Soey H. Sie, Rolando Lastra

"Abstract- The mineralogy of samples from the Wellgreen Cu-Ni-Pt-Pd deposit, Yukon Territory, is complex and the metals of interest are contained within fme-grained minerais which vary in size and mineral associations from sample to sample.The major Ni carriers are pentlandite and violarite; the major Cu carrier is chalcopyrite. About 700Jo of the major Ni carriers and 78% of the major Cu qmier will be liberated at a grind of 80% -'}f,.7 J.Uil (-500 mesh) for typical low-grade gabbro (West zone, sample No. 1). For typical ""clinopyroxenite"" (West zone, sample No. 2) and typical ""clinopyroxene-rich peridotite"" (East zone, sample No. 3) the liberation would be 71""lo and 65% for Ni, 74% and 60% for Cu, respectively. Fine grinding, however, cannot liberate the Ni contained in silicates and pyrrhotite, estimated to total24.5% for typicallow-grade gabbro (West zone, sample No. 1), 15% for typical ""clinopyroxenite"" (West zone, sample No. 2), and 12% for typical ""clinopyroxene-rich peridotite"" (East zone, sample No. 3).The principal Pt carrier (sperrylite) varies considerably in grain-size between samples and fme grinding, required to liberate the major Ni and Cu carriers, may be counterproductive in samples where sperrylite is relatively coarse-grained, as sorne would then be unrecovered (e.g. sample No. 1). In addition, sperrylite in samples No. 2 and No. 3 is closely associated with magnetite.Palladium occurs in diverse ways. It occurs in the form of several Pd minerais (e.g. sudburyite, testibiopalladite, merenskyite), as a replacement for Ni in several tellurides, antimonides and tel­ lurantimonides (e.g. melonite), or as very low concentrations in pentlandite (up to 34 ppm), chal­ copyrite (up to 9 ppm), and pyrrhotite (up to 5.6 ppm). Palladium minerais and Pd-bearing minerals are strongly associated with chalcopyrite in sample No. 1 and will thus report to a Cu concentrate. However, 22% of the total Pd is in solid solution in pentlandite in this sample and will thus report to the Ni concentrate. In samples No. 2 and No. 3, less Pd occurs in solid solution in pentlandite, and the PGM are distributed mainly among pentlandite, chalcopyrite, and magnetite in sample No. 2, and among pentlandite, pyrrhotite, chalcopyrite, and magnetite in sample No. 3. Therefore, the feasibility of magnetic concentration should be investigated for samples like No. 2 and No. 3, in order to improve Pt and Pd recoveries.Rhodium was found to occur as rare hollingworthite, in sparse cobaltite (up to 2.7%) and, as low concentrations in chalcopyrite (to 10 ppm) and pentlandite (to 12 ppm) by proton microprobe. Iridium occurs in hollingworthite (up to 7.8%) and very rarely as the native metal or in an undefmed Re-Ir-Os-Ru alloy. Ruthenium was determined by proton microprobe analyses to occur in pentlandite (up to 13 ppm) and chalcopyrite (up to 10 ppm), in addition to rare laurite and Re alloy."

Jan 1, 1993

By Gordon W. Hines

This paper, dealing with network planning in an industrial complex, discusses the type and size of project that can be handled on a manual basis. After a review of the fundamentals of network planning, and specifically of the Critical Path Method, the author analyses several different types of projects, each with its own characteristics. Some can be handled in conjunction with a computer, but others can be dealt with equally well without one. Among the projects discussed are a blast furnace reline, the installation of a billet mill flying shear, and routine maintenance-type operations.

Jan 1, 1967

By G. E. Willey

F OR many years, only one grade of structural steel has been used in volume in Canada. Its characteristics have not been altered appreciably and its long use speaks well for its performance. This standard grade of structural steel may be bought and specified as C.S.A. G40.4 steel or the American equivalent, A.S.T.M. A7. The principal limitations and requirements of this specification are shown in Table I. Within the last five years there has been a growing awareness among the steel producers and steel fabricators that economic forces are at work which make desirable the availability of new and better grades of structural steel. Competition from other materials has increased. The use of concrete bridges and pre-stressed concrete beams is a prime example. New sources of steel from outside the country have become a threat to the Canadian industry and its high cost-price structure. The need for improved properties in the steel, to make possible technologic

Jan 1, 1962

By Knud Sinding

Mining firms are widely criticised for their adverse impacts on the environment. At the same time many firms in the industry devote extensive resources, both financial and managerial, to the reduction or elimination such impacts. Very considerable improvements have been made, although these are sometimes overshadowed by a few high-profile accidents, such as the occasional collapse of a cyanide-containing tailings dam. In parallel, much effort is also directed at projecting a positive environmental image, as witnessed by extensive environmental reporting, both on paper and increasingly through web-platforms. Mining projects today almost invariably involve some form of environmental protection. In industrial countries regulations in this area are extremely stringent, as is enforcement. In less well developed countries, regulation and enforcement may be weaker, but firms are in many cases and for a number of reasons committing themselves to high levels of environmental protection, even if they might get away without doing so. Research in the area of environmental performance of mining firms has so far paid much attention to concepts such as sustainability indicators and the sustainability of individual firms. Given the still raging debates about the appropriate way to determine the degree to which any given firm is sustainable (Welford 1995) as well as the usefulness of what will in the final analysis be a value judgement, anyone on the sidelines of the debate will come back to the fundamental issue, how is knowledge that a particular firm has been judged ?sustainable? going to be made use of. This issue remains unresolved, which may explain the lack of progress in formulating a useful definition of a sustainable firm The question addressed in this paper is not so much about what firms are doing on the ground or in any particular case of environmental protection, but more in the subsequent use of these efforts - and by extension - on the overall direction of corporate environmental strategy. The fundamental problem facing all mining firms is that they cannot easily benefit from unilaterally reducing their environmental impact. The firm can of course avoid liability and keep a variety of stakeholders happy and hence experience lower costs of obtaining the [input] resources they need (in a broad sense, not just minerals), but this represents only part of the opportunities available form pursuing an environmental strategy (Reinhardt 2000). The other part, which may have an enormous potential, involves the concepts of competitor management and product differentiation. The logic of keeping stakeholders happy has been most forcefully argued by Pfeffer and Salanchick (1978) who link the behaviour of firms in all domains to their ability to obtain the resources they need, at a cost that is lower than it would otherwise be (Pfeffer & Salanccik 1978). Several varieties of strategy can be included under this heading, including cost reduction and risk management. The alternative logic is to convince customers that they want to pay more for minerals supplied by mining firm X or directly attributable to mine Y, or by making all mineral users pay more. These two strategies, which may be referred to as product differentiation and competitor management, respectively (Reinhardt 2000) are related to the demand side of mineral supply, whereas cost reduction and risk management are related to the supply side. Mining firms have not pursued the demand side very much, if at all. This is probably due to the extreme difficulty of moving mineral products, bulky and unglamorous as they are, away from their

May 1, 2003

By Brian L. Beninger

This paper discusses the application of the computer to coal preparation process predictions. In broad terms, the computer is used to perform two main functions. Firstly, the given float-sink analysis is interpolated and extrapolated to cover the entire actual range of raw coal specific gravity. Assumptions based on historical data must be made at times. Secondly, the partition curve, which, from historical data, defines the efficiency of a specific coal washing process, is applied to the washability data in order to determine the expected clean coal yield and quality. The vast amount of numerical work which is required to make a prediction of this type exhibits the need for computer methods in this area.

Jan 1, 1979

By A. O. Dufresne

The mineral wealth of pre-Cambrian rocks in Canada has been the subject of much study by geologists and engineers (members of this Institute), particularly so in the past few years, following discoveries of mineral deposits in areas far a part. This interest is well worth sustaining knowing the numerous rich producing mines within the pre-Cambrian formations, and the vast area covered by its rocks throughout this country. The pre-Cambrian has yielded minerals, both metallic and non-metallic; of these a much diversified list could be made. In more than one district we can point to mining as being responsible for the opening up of new sections, attracting a population into regions which otherwise would have remained virgin land of little commercial value. In these pre-Cambrian formations are found the rich copper deposits of Michigan, producing without interruption since 1845, and from which seven billion pounds of copper has been won; while in Minnesota and the adjoining district, at the head of Lake Superior, are mined iron ores which have rendered possible the great steel manufacturing industry of United States, the base of the economic structure of that wealthy country. The pre-Cambrian has given Canada the nickel-copper mines of the Sudbury district, the silver deposits of Cobalt and the gold camps of Porcupine and Kirkland Lake. With all of these our members are familiar; and it suffices to mention them to bring to mind pictures of the wealth and 'the growing population, in a word the importance of mining in?those sections of the country.

Jan 1, 1926

By Dwayne D. Tannant

The Adra tunnel near Naramata BC experienced a fire in 2010 that burned timber sets within the tunnel and caused severe spalling of rock from the roof and tunnel walls. The nature of the damage is documented and efforts completed to rehabilitate and open a portion of this tunnel to the public are described. The use of shortcrete and rock bolts is a technically and economically superior support system to timber sets as well as being far more fire resistant.

Jun 1, 2012

By G. Beckstead, L. Gormely, R. Zimmer, K. Hanneman, B. Nethery

As part of the EIS and permitting activities for the Pogo Mine in Alaska, a risk assessment study for the water management plan was carried out. The basis for the study was a site water volume and contaminant balance model. Probabilistic modeling was carried out using the @Risk Monte Carlo simulation package to investigate the frequency, quantity, and quality of discharges under varying assumptions. The results were used in discussions with regulatory officials as part of the permitting process for the project. The simulation allows probabilistic modeling of key environmental parameters based on input frequency distributions involving both quality and quantity of flow. When combined with predictions of water treatment plant capacities and removal efficiency, this was very useful for defining the likelihood of important regulatory outcomes. Based on the model, certain project modifications were made. Using the simulation as a basis, ongoing dialog with regulators led to consensus that all potential risks have been considered and mitigated for the Pogo Mine according to their likelihood and severity, and that regulatory requirements would be achieved. The paper describes the model and some of the applications for which it was used.

Jan 1, 2005

By H. D. B. Wilson, D. T. Anderson

"Canadian sulphide deposits generally have characteristic compositions. Metal associations in ore deposits and in igneous rocks are similar.Nickel: sulphur ratios, copper-nickel ratios, and nickel :cobalt ratios in copper-nickel sulphide ores are characteristic for most orebodies. Nickel, as sulphide, is highest in ores associated with ultrabasic rocks, whereas copper is highest in ores associated with gabbros. Cobalt is relatively constant. The metal ratios in copper-nickel ores are due, first, to the composition of the related igneous rock or magma; second, to the partition ratios of the metals into the sulphides when separating from the silicate rock or magma; and third, to the conditions at the time of deposition. Each factor is discussed and the evidence indicates the Frood orebody is a magmatic segregation in place and Falconbridge is an injected sulphide melt. Many Canadian orebodies containing copper, zinc, or lead also have relatively constant compositions. •Copper and zinc are concentrated in gabbro and diorite, and copper-zinc ores in northwestern Quebec are spatially related to gabbros and diorites. The same three factors con-trolling metal ratios in. copper-nickel deposits should control the metal ratios in copper-zinc deposits if the metals come from the gabbro-diorite intrusions.The ratios of base metals in common sedimentary rocks are not similar to the ratios in orebodies. Base metal elements are mobilized during high-grade metamorphism, but much fundamental research is needed before the relation between metamorphism and ore deposits can be established on a sound basis. The distribution of elements in sulphide orebodies suggests that cop-per, zinc, and lead are deposited simultaneously .in relatively constant proportions rather than successively in a paragenetic sequence. Zoning may be due to different ratios of metals being deposited under changing temperature, pressure, and chemical environment, or may be the result of other processes."

Jan 1, 1959

By M. Stogran-Baker, E. Legault-Seguin

"Fluorspar mining in the St. Lawrence area of Newfoundland and Labrador began in the 1930s and ended in the mid-1980s. In 2013, Canada Fluorspar (NL) Inc (CFI) discovered a new ore body, the AGS vein, which proved amenable to more economic open pit mining methods and began developing this resource. This paper discusses the flowsheet development of the AGS vein deposit. Testing at SGS began in 2009 with samples from other deposits in the area. The testwork included pilot-scale dense medium separation (DMS), laboratory-scale flotation tests to develop the flowsheet and a flotation pilot plant. The more recent work that is presented here has been devoted to the AGS vein, and included a variability testing program that gave tremendous insight into the metallurgical drivers of processing the deposit. The ore was found to be fairly variable in terms of fluorite grade, but also gangue mineralogy, which had greater implications on the DMS performance. The gangue mineralogy was also found to significantly impact the grindability characteristics of the DMS product. This paper will detail the testing conducted and the mitigating steps which were identified for the operation.INTRODUCTION Fluorspar is the industrial trade name for the mineral fluorite (CaF2), which is the primary industrial source of fluoride. There are a number of categories of fluorspar, most notably acid-grade fluorspar and metallurgical fluorspar (metspar). Acid-grade fluorspar has stringent specifications and is suitable for the production of hydrofluoric acid that is used for many applications. The typical specifications of acid-grade fluorspar are >97% CaF2 and less than 1% each of SiO2 and CaCO3, with a particle size distribution in the order of 80% passing 100 µm. Metspar is typically used for metallurgical purposes, typically as a flux in smelting, and has significantly more relaxed specifications (< 15% SiO2). The principle source of fluorspar in Canada has been from the Burin Peninsula in Newfoundland and Labrador. More than 3 million tonnes of fluorspar were produced there between 1940 and 1978 and from 1987 to 1990, when production ceased (Fulton & Montgomery, 1994)."

Jan 1, 2018