Search Documents

By T. C. Holmes

Introduction The Dome mine, in the Porcupine mining camp of northern Ontario, is one of the important gold mines of the country, having produced over 139 million dollars worth of gold from the commencement of production in '1910 to the end of 1944. The geology of the mine is complex and a number of types of ore are known, each occurring under particular conditions. The mine workings are very extensive and by far the greater part of them have been geologically mapped only in reconnaissance fashion. By 1940, when the writer joined the mine staff, the orebodies in the sedimentary trough and the 'nose' orebodies, the first types to be developed, were almost worked out and many workings were inaccessible, so the descriptions of these types are based largely on study of the plans and records. The same applies to a lesser extent to some other types. At various places in this paper, statements are made as to the mineralogical or chemical composition of the rocks. Most of these determinations are based on examinations made with a hand lens and cannot, therefore, be regarded as very reliable. General Geology As there are several types of ore in the mine, occurring under quite diverse conditions, a brief outline of the geology is given here, sufficient to provide a general picture into which the fuller descriptions given with each type of ore can be fitted.

Jan 1, 1947

By J. Doucet, C. Price

In an industrial setting, operational changes are continually introduced, driven by new technologies or changing economics. Because of day-to-day variability, quantifying the impact of these changes based on metallurgical performance requires long trial periods to achieve statistically significant results. Tools and techniques developed by the mineral processing group at McGill University have allowed for direct measurement of process variables (e.g., bubble size, gas and solid holdup). Two case studies are described where direct measurement techniques were used to evaluate: a) a new rotor stator mechanism; and b ), the introduction of a new frother type. Application of these methods has accelerated the evaluation of process changes and improved confidence in results.

Jan 1, 2009

By L. Gonzalez-Sardi, W. McCombe, M. Pearson

Pressure oxidation is increasingly being used for processing refractory sulphide ores and concentrates because it offers highly effective base metal and precious metal extraction while minimizing elemental sulphur, arsenic & mercury emissions. Yet pressure oxidation processes introduce new safety concerns and process risks as demonstrated by a number of safety incidents over the last 20 years, including overfilling, oxygen-metal fires, nozzle/sparger failures, and uncontrolled pressure relief events. Chemical Process Safety regulations in the United States and Canada mandate that companies constructing or operating chemical process facilities perform a rigorous hazard and risk analysis based on either ANSI/ISA-84.00.01 or IEC 61511 safety standards to determine the level of protection required for each hazard in the plant. This paper describes the application and implementation of three (3) unique safety instrumented systems developed by Hatch for ensuring the safe operation of three different pressure oxidation processes.

Jan 1, 2014

By H. Ito, T. Takasu

Effects of a mechnochemical treatment to oxide Ni ores have been investigated to enhance the extractive ratio of Ni from them in acid leaching process. High intensity grinding by a planetary boll mill showed strong effect to enhance the extractive ratio of Ni, for example , 10% of extractive ratio of Ni in sulfuric acid leaching(0.05mo1/1,at room temperature) increased to more than 90% with 60min. of planetary boll milling. Effects of additives(sulfur and some oxidants) on the mechnochemical treatment have also studied. Sulfur showed almost no effect to enhance the total Ni extractive ratio but increases the selectivity of Ni extraction. More than a half of Ni could be extracted by water when Ni ore was grinded at addition of Na2S207 in the milling treatment. Some effects of mechnocemical treatments to Ni ore are summarized in this paper.

Jan 1, 2005

By M. W. Grabinsky, B. D. Thompson

ABSTRACT: Use of cemented paste backfill (CPB) offers economic and environmental advantages over other backfill methods. However, many operations have limited knowledge of how their CPB behaves in situ. Therefore, to avoid over-pressuring containment barricades, backfilling strategies necessarily tend to be conservative. In situ monitoring at Barrick Gold Corporation’s Williams Mine and Inmet Mining Corporation’s Cayeli Mine has been conducted and factors controlling barricade pressures are demonstrated, including rise rates, binder content, stope geometry, and tailings properties. The application of barricade pressure monitoring on a stope-by-stope basis can increase backfilling efficiency and, thus, reduce stope cycle times, while maintaining optimal safety.

Jan 1, 2011

By Robert Macdonald, William Coombe, John F. Lewry

Gold occurrences have been known in the La Ronge Domain for many year . Mineable reserves have more recently been outlined and there is every prospect of a major gold camp being established in the domain within this decade. The La Ronge Domain lies in the Lower Proterozoic 'Trans-Hudson Orogen' and is part of a collage of Early Proterozoic crust comprising volcanoplutonic arcs, batholiths, associated volcaniclastics and volcanogenic sediments lying between the Superior Craton to the outheast and the reworked Archean basement/Aphebian cover terrain to the northwest. The domain has several lithostructural subdivisions, the most important of whjch , from a gold exploration point of view, is the Central Metavolcanic Belt. This belt is composed dominantly of a range of metavolcanic rocks and gabbroic to granitic intrusives, which geochemically resemble younger subduction-generated 'primitive' arcs developed on oceanic crust. U-Pb zircon geochronology indicates that the arc volcarusm and pre- to late-kjnematic plutonism occurred about 1890 Ma to 1850 Ma ago. The belt has an attained grade of upper greenschist to amphibolite facies and is relatively undeformed , though high strain zones occur locally. Most gold occurrences in the La Ronge Domain have been found in the Star-Waddy Lakes area of the Central Metavolcanic Belt, and in the Sulprude-MacKay Lakes area to the south which is interpreted as a tectonically dismembered part of the main belt. Both tratiformand vein-type gold occurrences are present in the domain; vein-type predominate and form nearly 90 per cent of the occurrences. The stratiform-type occurrences show a regional lithological a sociation with iron-rich sediments within proximal felsic volcanjc sequences. Some vein-type occurrences appear related to brittle fracturing associated with intrusive emplacement (the magmatic-hydrothermal "syn:' and "subvolcanic" veins) and faulting. However, most of the vein-type occurrences exhibit a spatial association with regionalscale ductile shear and other high strain zones, and were probably formed by metamorphichydrothermal processes.

Jan 1, 1986

By A. H. Ransom, M. E. Robb

The Salmita Gold Mine is located 240 air kilometres northea t of Yellowknife on the east shore of Matthews Lake. Salmita is one of several gold showings which are regionally associated with the steep easterly dipping contact zone between mafic, intermediate and fe lsic volcanics to the west and overlying finely laminated argillaceous sediments to the east. The volcanic assemblage forms a narrow 2 m to 7 m wide north to northwesterly trend ing Belt of Yellowknife Supergroup Archaen greenstone rocks. The contact zone exhibits exhalite character and the increased sulphide content provides a di stinct VLF-EM , IP/Resisti vi ty and/or magnetic signature. Gold occurs at or near this contact in three main settings: associated with si liceous vein-like structures; with finely disseminated sulphides within ericitic altered upper fe lsic tuffaceous unit ; or with quartz in narrow shear zones within the overlying sediment . The B-Vein is of the former type with free mi ll ing gold occurring within a highly sil iceous zone having an average widtn of 1.69 m. Alteration is intense within the immediately su rrounding host lithologies and includes the development of si lica, carbonate, sulphide, sericite and chlorite with minor graphite, epidote. tourmaline and scheelite. The mineable zone above the 4th level (-200 m) ha an average strike of 160 m and is divided into three south plunging ore shoots separated by the regional Salmita Shear Zone in the south and by a low-grade structural hiatus in the north. Production from the B-Vein commenced in August 1983 based on a diluted in situ ore reserve of 140,000 t grading 26.6 git Au . As of December 31, 1985, a total of 131 ,537 t grading 27.8 git Au have been mined at a ra.te of 160 t per day and a 96.4 percent recovery, to produce 3,522 ,000 g (113,227 ounces) of gold . Current (January I, 1986) reserves total 45,500 t grading 37 g/t Au down to the 10th level (-500 m) .

Jan 1, 1986

By Charles B. Newmarch

Abstract In the course of coal studies undertaken by the B.C. Department of Mines in southeastern British Columbia, special attention was directed to problems of coal seam correlation. Methods that had been used successfully in other coalfields were found, in the Crowsnest area, to have a restricted use or furnished only additional evidence that might prove helpful when used in conjunction with other criteria. A correlation technique involving semi-quantitative spectrographic analyses of coal ashes was developed. Elements detected in the ash include Si, B, P, Fe, Mg, Mn, Pb, Ti, Cr, Ga, Ca, Al, Ge, Ba, Mo, V, Ag, ?y;b, Na, Zn, Zr, Ni, Sr, Cu, K. Of these, the elements found to be most useful in correlation were Na, Ba, Si, V, and Mg. The element Na was invariably detected in the ash from one of the seams but was not found in samples taken from any of the others. In all of the four seams sampled statistically, significant differences in the amount of certain trace elements were noted. When the values obtained for these trace elements were portrayed in the form of histograms, the resulting diagrams had a characteristic shape for each seam. The diagrams provided a basis for seam identification within the limited area (8,000 feet by 4,000 feet) that was investigated. Introduction During the field seasons of 1946, 1947, and 1948 the British Columbia Department of Mines undertook a geological investigation of the coal measures of southeastern B.C. As field work progressed in the Crowsnest area it was found that, within the Kootenay formation, which contains all the commercial seams of the region, the coal beds are the most persistent stratigraphic units. Because of relatively rapid changes in ?both the thickness of the seams and the interval between seams, difficulty has invariably been experienced in attempts at correlation. Even short-range correlati0ns by able geologists who have worked in the Crowsnest coal basin have been questioned by the operating companies. It was apparent, therefore, that a more dependable correlation technique was needed so that stratigraphic and structural studies could be of greatest value. This paper presents, firstly, a summary of the results obtained in attempted correlations using methods that have been found effective in other coalfields. Secondly, a method based on semi-quantitative spectrographic analysis of coal ash is described and the apparently promising results are discussed.

Jan 1, 1950

By Juliana Parreira

The past decade shows record increases in global demand for minerals and metals with an accompanying significant decline in skilled personnel. Mining companies today are examining new technologies to maximize production, reduce costs, and create safer work conditions to deal with this shortfall. Automation of an open-pit mine haulage system is receiving attention as a beneficial option since it provides more consistent and efficient operation of mining equipment, it removes workers from potential danger, it reduces fuel consumption significantly reducing greenhouse gas (GHG) emissions, and it can help optimize vehicle repairs and equipment replacement because of more-predictable and better-controlled maintenance. This paper describes a simulation model under development using the EXTENDSIM software package to examine scale-up issues and constraints of autonomous vehicles in comparison to a manual system. The software can predict and manage Key Performance Indicators (KPIs), such as productivity, safety, cost, equipment failures, fuel consumption, and tire wear under different road and load conditions. By breaking-down the various systems of an autonomous haulage truck and simulating the overall haulage system using a Monte Carlo approach, the model becomes a flexible and powerful tool to use within a mining organization. Direct comparison to a manuallyrun system can be done to show the cost and operational benefits of automation. Project managers can use this tool to guide decision-making about possible application of autonomous haulage trucks at a specific mine site.

May 1, 2010

By A. T. Jakubick, A. MacG. Robertson

This paper reviews key issues related to the placement of dry (soil) covers on extremely weak, compressible fine tailings. The design and construction of soil covers on such tailings often presents a formidable challenge to the geotechnical as well as the environmental engineer due to the low shear strength, poor traffic ability, and high settlement of under consolidated tailings at the time of reclamation. The geotechnical issues to be considered include: (1) consolidation of near-surface tailings to achieve strength gains, improve traffic ability, and allow safe placement of initial cover layer; (2) stability of tailings slopes during dewatering of tailings ponds and/or cover placement; and (3) long-term settlement of tailings and its impact on cover integrity and final surface shaping. The environmental issues to be considered include: (1) management of contaminated (free) pond water; (2) management of contaminated pore water expelled during tailings consolidation; and (3) management of (uncontaminated) surface water on top of the cover. This paper summarizes recent experiences gained in a large uranium tailings reclamation project. It is concluded that a careful consideration of both geotechnical and environmental issues during the planning stages greatly reduces the costs and environmental risks associated with fine tailings reclamation.

Jan 1, 2000

By J. G. Kelly, C. P. Brown

"In June 1983 a new borehole hoisting system was commissioned at Sherritt Gordon's Fox Mine. Twelve hundred tons-per-day of ore from the 2600 and 2800 levels are being hoisted to the 2000 level through an 8-jt diameter bored winze. This new method replaces the diesel truck haulage system which had been in operation at the mine since 1975.A study was initiated in 1980to determine the most effective method of achieving the required production. The study examined several hoisting alternatives including: expanding the existing trucking system; converting to electrically -powered truck haulage; and deepening the skip compartments of the existing main shaft. The alternative selected as the hoisting method most suited to the requirements was borehole hoisting.Development of the new system commenced in April 1982. Underground excavations included 700 feet of 8-ft diameter borehole, a hoistroom and headframe, storage bins, and a grizzly and rockbreaker station. Equipment installations included: a 5-ft diameter double-drum Nordberg hoist; a counterweighted Kimberley-type skip; two rockbreakers; and the steel sets in the winze. These installations were completed in June 1983. Some problems were encountered after the initial commissioning but these were solved, and since August 1983, the system has proven that the designed capacity is achievable within expected costs."

Jan 1, 1985

By F. Baczek, S. S. Rocks, D. Chaiko, T. Walters

The atmospheric leaching of chalcopyrite concentrates using acidic ferric sulfate lixiviants is well known to suffer from slow leach kinetics and poor copper recoveries. A number of approaches have been proposed for improving both leach kinetics and recoveries in this system. Many of these, while effective, suffer from high CAPEX and/or OPEX. As many mine sites begin transitioning from heap leaching of copper oxides to processing of primary copper sulfides, cost-efficient leach processes that are compatible with existing SX/EW processes will be needed to maintain existing cathode production. To this end, FLSmidth is exploring process options and reactor technology for the hydrometallurgical processing of primary sulfides. One approach that appears to be highly effective at increasing copper recoveries takes advantage of the enhanced reactivity of transitory, surface-defect structures generated during particle fracture. Significant process efficiencies are gained by matching the rate of grinding to the rate of electrochemical leaching in Mechano-Chemical leach processes. The patent-pending FLSmidth® ROL process uses a Stirred Media Reactor (SMRt reactor) to achieve copper recoveries of 97+% in 6 hours or less. This approach overcomes many of the surface passivation problems that have hindered other atmospheric leach processes. New insights to leach mechanisms are presented.

Jan 1, 2015

By H. O. Seigel, J. C. Gingerich, E. O. Köstlin

"To satisfy their continuing need to replenish or expand their ore reserves, mining companies are faced with the dilemma of arriving at a proper balance between the dual avenues of discovery through in-house exploration and of acquisition of properties that are relatively proven or are even in production. The returns from exploration activities may be spectacular, but are unpredictable. The allure of an acquisition lies in its promise of quick and risk-reduced addition to reserves. However, it is historically clear that quantum increments in shareholders’ values have arisen primarily through major exploration discoveries, rather than through major late-stage acquisitions. Late-stage acquisitions can prove highly profitable, sometimes based upon the planned use of superior mining or metallurgical technology, but more often occur as the result of unexpected windfalls. At the other extreme, they can become expensive failures through inadequate due diligence, or unforeseeable factors.Citing numerous case histories and industry statistics, it is concluded that a judicious combination of both exploration activity and the acquisition of prospects is the most advantageous strategy for adding new ore reserves. A skilled exploration staff is essential for success, be it through exploration discoveries or through opportunistic acquisitions, preferably at their early stages. In the future, it is anticipated that there will be fewer opportunities for acquisition because of reduced funding for junior exploration companies, leading to increased competition and higher costs for fewer properties, both in the advanced exploration and mining stages."

Jan 1, 2002

By G. R. Elliott

Foreword The office of the Supervisory Mining Engineer, a branch of the l. Federal Government, is financially interested in no oil company and has no stock to sell. This office, however, is deeply interested in the proper and efficient development of Canada's natural resources. The people of Canada are interested in the petroleum development in Turner Valley for two principal reasons: As represented by the Department of the Interior, they are the largest owners of petroleum and natural-gas rights in the field; As a nation, they are vitally interested in the development of petroleum and natural gas as a national asset, and therefore, also, in all productive property, no matter who directly controls the leases. As has been stated by Mr. Charles C. Ross, Supervisory Mining Engineer, "The Department, being responsible for the administration of these public resources, necessarily requires regulations to protect them from abuse by lessees. Our portion of this responsibility is to record a complete history of all drilling operations and to see that proper drilling methods are adopted to prevent damage and wanton waste of the valuable natural resources under discussion." Not only does our position necessitate an impartial and a judicial viewpoint, but, being day by day in touch with all operations in the western provinces, we are uniquely situated to comprehend both individual and general problems.

Jan 1, 1930

By Tanai Marin

Modelling of pyrometallurgical processes can become extremely challenging when the process involves complex chemical reactions, phase change, multiphase flows, heat and mass transfer and fluid flow. Traditionally modelling involving complex thermodynamic equilibrium and thermochemistry are treated separately from problems in which transport phenomena are dominant, such as CFD and heat transfer studies. The separation is also necessary due to the lack of modelling tools that can effectively couple both solution thermodynamic and transport phenomena or even multiphysics problems. However, there are, quite often, problems in high temperature process metallurgy in which it is not possible to simplify this two modelling approaches. Typical cases of this are for example, the modelling of slag freezing on furnace walls (electric or flash furnaces) to create a protective layer in front of the refractories hot wall, the formation of build up from the matte or metal phases at the hearth of the furnace, calcine smelting from charging piles into slag phase, etc. The problem is even more challenging in nonferrous pyrometallurgy as most, if not all, of the condense phases are highly non ideal solutions involving several components and exhibiting complex crystallization paths and miscibility gaps, such as the Fe-Ni-Cu-S matte, FeO-Fe2O3-SiO2, FeO-MgO-SiO2 slags, etc. In this paper, an approach to model coupled problems involving multiphysics and solution thermodynamic is presented. The approach consists in developing in-house a library containing the Gibbs energy minimization routines and using the local equilibrium concept for process modelling from a multiphysics commercial software (COMSOL). Simple test cases, such as building a non-ideal binary phase diagram on a CFD package is presented, the limitations and of other classic approaches such as equilibrium or Scheil cooling are discussed and compared to this model.

Jan 1, 2015

By K. Chattopadhyay

Fluid flows in metallurgical reactors play a vital role on liquid metal cleanliness for both ferrous and non-ferrous metallurgy. Thus, it is absolutely critical to understand different fluid flow mechanisms, and the use of computational methods to model the complex non-isothermal, turbulent, single- and multiphase-flows, has to be appreciated. The present case study emphasizes on controlling the flow of liquid steel in a tundish and enhancing liquid metal cleanliness. CFD modeling was used to build a robust mathematical model, and effects of flow control furniture and non-isothermal conditions were analyzed. The mathematical model was validated against water model experiments. Parameters that were conducive for inclusion removal were identified and implemented in the plant. Some flow control devices could increase inclusion removal to a great extent compared to the existing configurations. In cases, where a hot ladle was poured into a relatively cooler tundish, inclusion removal was better, whereas results were catastrophic in cases where colder liquid was poured from ladle to the tundish. Similar techniques can be applied for other liquid metals including light metals and non-ferrous metals.

Jan 1, 2015

By F. S. Thurner

"This paper describes the engineering and construction activities of the ""design-build"" project awarded to the joint venture of Foundation-Comstock-Janin for the construction of the plant and wharf facilities, camp site, power plant and all supporting services. As a member of the Foundation Group of companies at that time, Fenco actecl as consulting and design engineers for the project. Particular emphasis is given to the problems which adversely affected design and construction activities due to prevailing arctic conditions and the remote location of the project. The paper also describes the approach taken in the investigation of the site and soil conditions as well as the selection of the special structures for the 225,000-toncapacity fibre storage building, the wharf structure for 50,000-dwt vessels, and the 1,000-tph-capacity reclaiming and ship-loading facilities . It further covers the logistics problems and the scheduling activities related to the short duration of the shipping season, and the transportation of equipment and mate1•ials by sea as well as by air."

Jan 1, 1976

By J B. McConnell

The Thompson smelter has three unique features which form the basis ~f its design: fluid bed roasters which treat nickel concentrate filter cake from the mill, as well as the flux, in order to achieve partial desulphurization; the use of electric furnaces for the smelting of the partially desulphurized, preheated roaster product; and the disposal of slag by water granulation and slag slurry pumping. The installation consists of three fluid bed roasters, each feeding an electric furnace. Nickel concentrate is received at the smelter via pipe line. It is thickened and filtered, and the filter cake, together with siliceous flux, is fed through rotary bin feeders and reciprocating double-gate seals into the fluid bed roasters. Air injected into the roasters through club-head tuyeres oxidizes part of the sulphur and associated iron in the concentrate. The heat of reaction dries and heats the charge. Roaster product is recovered from the gas stream in cyclones and from the roaster bed through automatic valves.

Jan 1, 1963

By M. Dupuis

It has been previously demonstrated [1,2] that using selective collector bar rodding has a big impact on the uniformity of the current density at the top surface of the cathode block and hence on the intensity of the horizontal current in the metal pad, The present study investigates the impact of using selective collector bar rodding on the MHD stability of a 500 kA aluminium electrolysis cell, For this purpose the recently developed MHD package for the aluminium reduction cell time dependent behavior is used.

Jan 1, 2005

By D. C. Peck, James. R. S., Chubb. P. T.

"Abstract -The East Bull Lake gabbro-anorthosite intrusion is one of several Early Proterozoic layered matie intrusions occurring along the Southern Province - Superior Province boundary in the Elliot Lake - Sudbury region, Ontario. The base of the East Bull Lake intrusion comprises abundant plagioclase cumulates (Leucogabbronorite Zone) hosting two distinct styles of sulfide mineralization: (1) disseminated magmatic sulfides, and (2) disseminated to massive, structurally controlled sulfides. Both types of mineralization are enriched in Pd, Pt, Au, Cu and Ni. The host rocks to the sulfide mineralization display a range of interesting features including nodular textures, dendritic­ pegmatitic matie pods, inclusion-rich zones (pyroxenite, anorthosite and granitic inclusions) and mag­ matie breccias. Disseminated chalcopyrite, pyrrhotite and pentlandite occur in concentrations of up to lOOJo within erratically distributed gossan pods near the base of the intrusion. The sulfides were originally precipitated from intercumulus liquids, but were subsequently recrystallized and locally remobilized along fractures during the major period of metamorphism and deformation that af­ fected the East Bull Lake intrusion. The base- and precious-metal tenor of the structurally controlled sulfides can be explained by extensive remobilization and reconcentration of the pre-existing magmatic sulfides in the vicinity of a major shear zone. Both styles of sulfide mineralization locally contain ppm abundances of POE + Au and are generally Pd- and Cu-rich, although both display large variations in Pd :Pt and Cu:Ni ratios. The magmatic sulfides are more strongly enriched in POE and contain up to 1470 ppm Pd in 100% sulfide. Severa! factors, including source characteristics, magmatic processes (crustal assimilation, fractional crystallization) and post-magmatic inter­ action with hydrous fluid, have influenced the present distribution of POE, Cu and Ni in the East Bull Lake intrusion .The magmatic sulfide occurrences from the East Bull Lake intrusion compare favorably with marginal-type deposits from rift-related intrusions (Noril'sk-Talnakh region, Siberia; Duluth Com­ plex, U.S.A.) in terrns of their distribution, but are most similar to reef-type POE deposits with respect to their base- and precious-metal geochemistry. The combination of high POE tenors and large tonnages that is observed for the POE-Cu-Ni mineralization from the East Bull Lake intrusion suggests that a good potential exists for the presence of economie concentrations of Pd, Pt, Au, Cu and Ni in the intrusion. On a global scale, the East Bull Lake intrusion is part of a suite of Early Proterozoic plutons, many of which contain significant volumes of stratiform and/or marginal­ type POE-Cu-Ni mineralization. The East Bull Lake intrusion is also one of the oldest mineralized intrusions derived from a sub-Superior Province mantle source region that has given rise to several significant magmatic POE-Cu-Ni deposits during the period 2.5 Ga to 1.1 Ga."

Jan 1, 1993