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By M. L. Jeremic

Altered and unaltered coal from the Star-Key Mine near Edmonton, Alberta has been tested under compression and under tension. The test results showed that altered coal samples have an appreciably lower strength than unaltered coal. Altered coal samples do not give a linear load-displacement curve, peak strengths are poorly defined and yielding is observed over a range of loads, so the material can be regarded as relatively plastic. However, unaltered coal samples produce a linear loading curve with a high tangential modulus and an easily distinguished peak strength at which there is a sudden brittle failure. These findings lead to important differences in the theoretical design of ribs and pillars in underground mines in the two coal types. The substantial differences in the strength properties and behaviour of the two types of coal are governed by a higher intensity of cracks in the weathered coal. Two causes of the additional cracking can be suggested-subaerial weathering and subterranean weathering of the coal.

Jan 1, 1979

By G. F. MacDonnell

THE Privateer mine consists of a group of mineral claims situated in the Zeballos area, on the west coast of Vancouver island, approximately 180 miles north of Victoria. Although Zeballos is a comparatively new mining camp, its transportation facilities can be considered exceptionally good. General freight and supplies are brought in by either C.P.R. or Frank Waterhouse steamers from either Victoria or Vancouver. Service by these boats varies from five to ten days and the trip from Victoria takes approximately two days. Passengers may use the C.P.R. boats, or, if speed is essential, they may fly, in which case they have the choice of two flying companies, namely, Canadian Air-ways, Limited, and Ginger Coote Airways. The average flight from Vancouver takes approximately two hours. Excellent unloading facilities are provided at the beach by a government dock for the steamers and a floating dock for aeroplanes. The mine, which is approximately five miles from the beach, is serviced by a fairly good gravel road, which has proved satisfactory for all haulage purposes. Zeballos has the reputation of having one of the heaviest rainfalls on the west coast, but as no accurate records have been kept, no comparisons can be made. H. C. Gunning, in his report, comments on the weather from 1929 to 1932, and one would judge that the practically continuous rainfall did not add to the pleasures of the field work. During the summer of 1938, the opposite condition prevailed and the area had exceptionally dry and pleasant weather. The snowfall is generally light at the lower elevations, but very heavy higher up. No extreme cold weather is encountered during the winter, which is generally short.

Jan 1, 1939

By T. Orser

In 2010 Newmont made the decision to purchase a 42 foot (ft) Semi-Autogenous Grinding (SAG) mill from Metso and a 28 Mega-Watt (MW) Gearless Mill Drive (GMD) from ABB for the Conga Project in Peru. The test and study work showed that a single line 42 ft SAG mill circuit gave the most favorable project economics in comparison to an equivalently powered single line 40 ft SAG mill circuit. This paper does not address the process design or the project economics, but instead focuses on the key aspects of the SAG mill design, GMD design and the associated component manufacturing. This paper also addresses, where applicable, the potential reliability differences between the initially proposed 40 ft SAG mill and the finally accepted 42 ft SAG mill.

Jan 1, 2012

By J. Jerome MacDonald, Stephen B. Flewelling

"In the base metals industry of today, operations required to continuously improve productivity and reduce unit production costs. Consistent with these goals is the improvement of the muck haulage cycle from open stopes with the No. 12 Mine.Existing haulage from open stopes occurs with LHD units experience at Brunswick indicates that LHD units have a higher unit cost per tonne mucked than loader-truck combinations when the haulage exceeds approximately 150 m.The reintroduction of open stoping at Brunswick made existing loader-truck combinations unsuitable. It was recognized that application of recent continuous loading technology could potentially result in significant unit cost savings and productivity increases.A review of the technology resulted in the testing of the Voest Alpine AL60 loader in the open stopes located on the 1000m Le vel. Testing began in January 1988 and finished in late November 1988. The test will provide experience as well as quantified production and maintenenace parameters f or the purpose of quantifying production unit costs and system productivity, ultimately resulting in a decision to further utilize or not utilize the loader as a primarymucking unit at Brunswick .INTRODUCTIONBrunswick Mining and Smelting Corporation Ltd. produces approximately 10500 tonnes per day from the No. 12Mine located 35 km southwest of Bathurst, New Brunswick Mining is the largest (single mine) producer of zinc in the world having mined over 52 million tonnes since 1964. Many years of production still remain with proven and probable reserves in excess of 90 million tonnes. Reserves grade at an average of 3.65% Pb. 8.99070 Zn, 99g/mt Ag and 0.32% Cu . The operation employs 1446 people with approximately 800underground including operations and maintenance staff.In the No. 12 Mine two major mining methods are presently utilized . The primary method is Mechanized Cut and Fill (MCF) accounting for approximately 6500 tonnes per day from four major areas. The remaining 4000 tonnes per day is produced from open stopes with the majority of 2800 tonnes per day being produced by the 1000 level.The 1000Level contains 30 million tonnes segmented into open stope blocks 30 m high, 15m and 30 m on strike , with a transverse width of 10m to 50 m (Fig. I). Stopes are organized on a primary secondary stope arrangement along strike. Primary stopes are undercut and overcut full size with the back fully cablebolted. All stope and lateral development is driven 4.0 m high. All stopes to date are flat bottom (Fig. 2). Primary stopes are filled with cemented rock- fill , secondaries with conventional rockfill, Haulage from the stopes is primarily with 8-yard LHD units ; mucking is approximately 50% conventional and 50% remote. Haul distance to date has averaged approximately 150m with current stope haul distances of approximately 300m. Haulage is presently to a small jaw crusher situated on the 1000 Level. From August 1989on, haulage will be to a set of ore passes feeding to a large gyratory crusher situated on the 1200 Level. Start up of the gyratory crusher corresponds to an increase in tonnage from 1000 Level to 4100 tonnes per day."

Jan 1, 1989

By Jasmin Raymond

Ground source heat pumps are used to heat or cool building and heat water supply. Such heat pumps use the earth as a heat source or sink to efficiently provide or store thermal energy. For example, a ground source heat pump typically requires less then a third of the electric or fossil fuel energy of a conventional heater. Ground source heat pumps could therefore help reduce the energy consumption of active mines where low-grade geothermal resources are abundant. In most heat pumps, water or a water-antifreeze mixture having a temperature ranging from -6.5 to 43.5 °C is circulated through a heat exchanger at a rate of 0.000033 to 0.000067 m3/s (2 to 4 L/min) for each kilowatt of heating/cooling capacity. The groundwater that is continuously pumped to drain mines could be used to operate heat pumps. Water feeding a heat pump can alternatively circulate in a close loop network of pipes buried underground or installed in a surface water body. Retention water ponds, tailings and waste dumps commonly found at active mine sites could provide excellent environments to install the close loop system. Further research will help take advantage of the unexploited geothermal resources associated with actives mines.

May 1, 2007

By A. J. Monhemius

"This paper reviews the history of modern iron-control processes in hydrometallurgy. Attention is paid to processes developed in the electrolytic zinc industry for removal of iron from zinc sulfate leach liquors and the problems faced by the industry in the safe disposal of the iron residues produced by these processes. Past lessons learned are projected onto current efforts to develop hydrometallurgical processes for treatment of copper sulfide concentrates. It is argued that any attempt to create a “hydrometallurgical copper smelter” will fail, unless methods are developed that can recover iron in a form that can be directly used by the steel or pigment industries.RÉSUMÉ Cet article passe en revue l’histoire des procédés modernes de contrôle du fer en hydrométallurgie. Il accordera une attention particulière aux procédés développés dans l’industrie du zinc électrolytique pour l’élimination du fer dans les liqueurs lixiviantes de sulfate de zinc anhydre, ainsi qu’aux problèmes rencontrés par l’industrie en termes d’élimination sans danger des résidus ferreux générés par ces procédés. En projetant les leçons tirées du passé sur les efforts actuels, on pourra développer des procédés hydrométallurgiques pour le traitement de concentrés de sulfure de cuivre. Beaucoup prétendent que toute tentative de créer une « fonderie de cuivre hydrométallurgique » échouera à moins de développer des méthodes permettant de récupérer le fer sous une forme pouvant directement être utilisée par les industries sidérurgique ou des pigmentsINTRODUCTIONThis paper resulted from an invitation to the author from the CIM’s Historical Metallurgy Committee to give a presentation on the early developments of iron control in hydrometallurgy. This was to take the form of a plenary lecture at the 4th Symposium on Iron Control in Hydrometallurgy, which formed part of the 28th International Mineral Processing Congress, held in Quebec City in September 2016.I was naturally flattered that the invitation was to give the lecture at an IMPC, the prestigious conference series that has been held since the 1950s. That this particular IMPC was to include the 4th Symposium on Iron Control in Hydrometallurgy, a conference series held only every 10 years, made the invitation even more appealing and appropriate. This was because I had been co-chairman of the First Symposium on Iron Control, together with my erstwhile colleague, John Dutrizac, which was held 30 years ago in Toronto."

Jan 1, 2017

By Stanley G. Butcher

"Introduction Many operators in western Canada, with a background in the minerals industry, talk of ""coal beneficiation"", whereas the coal industry generally uses the term ""coal preparation"" . The sophisticated cleaning circuits and thermal drying units found in western Canada makes the term beneficiation particularly appropriate. This chapter uses standard coal preparation terminology(l,2J and assumes general knowledge of coal preparation unit processes and equipment(3,4,5). The geologic setting and mining methods of western Canada, described elsewhere in this volume, present for preparation run-of-mine coals which have particular problems. As a result the cost of preparation is a higher proportion of the total minesite production costs than in other coal fields . Preparation requirements are determined by the types of coals being produced and the markets in which they are sold. Western Canadian coals have a low sulphur content and do not require cleaning on this account. Prepared coal from western Canada has to be shipped vast distances -to the Pacific Rim countries and Ontario in particular -and the savings in transport costs justify the high costs of preparation. Factors which dictate selection and operation of the preparation processes are: i) Market specifications and coal rank. ii) Size distribution of particles and particularly the liability of coal and refuse particles to degrade during handling and processing. iii) Quantity and characteristics of the associated refuse. iv) Washability characteristics (the distribution of particles by specific gravity within each size fraction). v) Surface characteristics of the fines. vi) Variability of the raw coal. Where the product (coal or discard) has a high fines content special consideration must be given to dewatering, the removal of surface moisture, to give acceptable handle ability characteristics. In the severe winter climate of the western foothills and mountains thermal drying is necessary to prevent freezing of washed coal in stockpiles and railcars."

Jan 1, 1985

By Lawrence D. Meinert

Abstract-Most large skarn deposits are zoned in both space and time relative to associated intrusions. Zonation occurs on scales from kilometers to micrometers, and reflects infiltrative fluid flow, wallrock reaction, temperature variations, and fluid mixing. The most spectacular examples of skarn zonation usually occur at the skarn-marble contact, where transitions between monomineralic bands can be knife sharp. Other small-scale examples occur in zoned veins and individual mineral crystals. Although, visually striking and scientifically interesting, in mineral exploration these small-scale variations are less useful than deposit- or district-scale zonation. In most skarn systems there is a general zonation pattern of proximal garnet, distal pyroxene, and vesuvianite (or a pyroxenoid such as wollastonite, bustamite, or rhodonite) at the marble front. As well, individual skarn minerals may display systematic color or compositional variations within the larger zonation pattern. Such patterns are reviewed for 14 well-studied examples of Cu, W, Sn, Au, and Zn-Pb skarns. In addition, many deposits have endoskarn or other alteration of the associated intrusion, and recrystallization or other subtle changes have occurred in the surrounding wallrocks. Copper skarns, such as Mines Gaspé in Quebec and Big Gossan in Irian Jaya, have high ratios of garnet:pyroxene and are zoned outward from the intrusion, to garnet, to pyroxene, to massive-sulfide replacement and vein deposits. Garnets in Cu skarn are Fe-rich and change from dark red-brown near the intrusive contact to paler brown, green, or yellow in distal locations. Pyroxenes in Cu skarns are pale and diopsidic near the intrusion, and become darker and more Fe- and Mn-rich away from the intrusion. Tungsten skarns, such as Salau and Costabonne in France and Pine Creek and Garnet Dike in California, have intermediate ratios of garnet:pyroxene, are more extensive vertically and along strike than perpendicular to the intrusive contact, and have zonation patterns commonly complicated by overprinting of metamorphic lithologies. In W skarns, garnet is commonly subcalcic and the pyroxene is Fe-rich, reflecting particularly reducing wallrocks or great depth of formation. Tin skarns, such as Dachang in China and Moina in Australia, also can have subcalcic garnet and Fe-rich pyroxene, but this reduced mineral assemblage typically is due to an association with reduced S-type granites. Tin skarns differ from most other skarn types in having a late greisen stage that may replace earlier Sn-bearing calc-silicate minerals, thus liberating Sn to form cassiterite. Many high-grade Au skarns, such as Hedley in British Columbia and Fortitude in Nevada, have low ratios of garnet:pyroxene and are associated both with reduced plutons and reduced wallrocks. Goldrich zones occur in Fe-rich, pyroxene-dominant, distal skarn. Zn-Pb skarns, such as the Yeonhwa- Ulchin district in Korea and Groundhog in New Mexico, have low ratios of garnet:pyroxene and generally form distal to associated intrusions. These skarns also are zoned from proximal garnet to distal pyroxene and pyroxenoid (bustamite-rhodonite), with significant zones of massive sulfides within and beyond skarn. Manganese enrichment of most mineral phases, particularly pyroxene, is characteristic of distal zones. Fundamental controls on skarn zonation include temperature, depth of formation, composition and oxidation state of associated plutons and wallrocks, and tectonic setting. Most W skarns form at relatively great depth, 5 km to 20 km, with extensive high-temperature metamorphic and metasomatic mineral assemblages. In contrast, most other skarn types are relatively shallow, <10 km and mostly <5 km, with limited, lower temperature metamorphic aureoles. Differences in oxidation state correlate well with different skarn zonation patterns, particularly garnet:pyroxene ratios and compositions, and can be used in both classification of and exploration for s

Jan 1, 1997

By W. T. Martson

ABSTRACT Sooner or later, every producing mine faces the question of fill. This paper invites consideration of mill tailings as an economical, efficient, and quantitatively adequate source of such fill. Some of the advantages, disadvantages, methods of utilization, and methods of treating mill tailings for sand recovery are covered. ADVANTAGES AND DISADVANTAGES OF SAND FILL DISREGARDING economic com-promise, that material which supports the greatest applied load with the least compression is the best choice for fill. Table I, reproduced from U. S. Bureau of Mines Bulletin 60, is offered as evidence of the adequacy of hydraulically placed sand. Table II gives the results of tests made in an effort to determine the reason for the difference between load hearing qualities of dry-placed and hydraulically-placed sand. From these, it would appear that hydraulic placing gives a denser initial packing, with corresponding higher, and faster development of, load bearing qualities. Assuming this to be true, then if sand from mill tailings can be placed underground economically, it is the superior fill material. Table III summarizes cost data available. The most cursory glance through the available references (2, 5, 6, 7, 8, 9) will show .that the major benefit from the adoption of sand fill is a decrease in the non-productive fill ?cycle of a working place. This, it is estimated, increases the output of an individual stope by from 25 to 50 per cent. The advantage of reducing the number of required working places for a constant daily production is obvious.

Jan 1, 1951

By Yang Shuxin, Guo Qiliang, He Ping, Lu Lizhi, Yao Rui

"We combined stepwise regression and constrained regression statistical method to obtain the best boundary conditions for the calculation of in-situ stress field in Wushaoling tunnel using finite element method. Our numerical results reveal that: the main geologic factors contributing to the initial background stress are gravity and tectonics; the principal stress values would drop in fault zones; the angle between the maximal horizontal stress and the axis of Wushaoling tunnel is acute; Wushaoling tunnel tends to become stable when this tunnel has 2:1 ratio of the height to its width; the possibility of rock-burst exists under high stress.INTRODUCTIONStress state of engineering region is an important factor affecting the stability of project. Geological disasters in the project area are closely related to their stress environment. Wushaoling tunnel which is 20,050 meters long, lying along Lanzhou-Wuwei segment of Lan-Xin Railway in China, is the key project of Lan-Wu double-track railway. The region surrounding this tunnel is under a high stress environment. Accurate identification of the stress environment of the engineering area and the interaction between geomaterials and geotechnical engineering construction holds significant scientific and practical value for engineering design, construction, and operation.Many scholars explored and discussed the present-day tectonic stress through investigations of tectonic evolution history (Ding, & Lu, 1986), crustal deformation (Zoback, 1992), focal mechanisms (Yang et al., 2003, Xie, Cui, & Zhao, 2004), and so forth. However, the above methods would only provide the approximate direction of the principal stress in a broad region, and could not give the absolute stress values. In-situ stress measurement is one of the primary means to directly gauge the current crustal stress. However, in-situ stress measurement can only be applied in small number limited by measurement conditions."

Jan 1, 2015

By K. Ramji

"The development curve in the extractive sector has become longer, steeper, and riskier due to increased social, legal, and political risks from various stakeholders. Indigenous peoples are a unique stakeholder because their growing legal rights to lands and resources can often determine a project’s outcome. A project will only be successful if it is able to obtain the legal permits, withstand any judicial reviews, and gain and maintain the social license to operate. Stakeholder identification, management, and engagement are key risk-mitigation tools required to successfully convert risks into opportunities.RÉSUMÉ La courbe de développement du secteur de l’extraction s’est allongée, elle est devenue plus abrupte et plus hasardeuse en raison de l’accroissement des risques sociaux, légaux et politiques venant des divers intervenants. Les peuples autochtones sont des intervenants uniques puisque leurs droits légaux croissants sur les terres et les ressources déterminent souvent ce qu’il adviendra d’un projet. Un projet ne pourra réussir que s’il est capable d’obtenir les permis légaux, passer à travers les analyses judiciaires, puis obtenir et maintenir le permis social d’exploitation. L’identification des intervenants, la direction et l’engagement constituent les outils clés de l’atténuation des risques nécessaires pour bien convertir les risques en possibilités."

Jan 1, 2016

By William Winsor, Harold L. Snyder

"AbstractShould oil and gas be proven in commercial quantities on the Labrador Shelf, current technology is not adequate for production operations in this severe environment, which includes yearly invasion of pack ice and icebergs. The fishery of this section of the North Atlantic is a vital resource to which a major oil spill or blow-out would impose an intolerable burden, This means that production systems must be designed and built to be fail-safe.The experiences of mining in Bell Island and Cape Breton have shown that it is possible to operate beneath the ocean floor, and this technology may hold the key for safe, reliable and economic production, This paper attempts to define particular problems and outline possible solutions.IntroductionOUR DISCUSSION is subject to the assumption that large hydrocarbon reservoirs will be discovered in the sedimentary basin of the Labrador continental margin. The petroleum industry has not attempted to operate in a harsher area. The Labrador coastline is exposed to North Atlantic storms and icebergs year’round, Arctic pack ice occurs up to six months of each year. However, there is no doubt that, if sufficient hydrocarbon potential is outlined, development will proceed."

Jan 1, 1977

A brief description of the hydro-gen reduction of nickel from ammoniacal solutions by the Sherritt process is given, indicating how this procedure can now be used to coat a great number of materials -particularly powders -with nickel or cobalt, whereby so-called composite powders are produced. The technique for the production of composite powders is described, particularly with regard to the surface activation of noncatalytic powders, whereby it is possible to coat core powders uniformly with nickel or cobalt. The properties of some of the more interesting composite powders, such as Ni/ AI, Ni/WC, Co/WC, Ni/Graphite and i/P, are discussed as well as possible fields of application for these new products. INTRODUCTION DURING the last decade, no-table advances have been made in pressure hydrometallurgy, so that large quantities of three of the more com1r.on metals, copper, cobalt and nickel are now produced on a commercial scale by hydrometallurgical processes.

Jan 1, 1963

By D. W. McDonald, N. A. Duke, R. L. Hauser

"Abstract- The NERCO Con Mine is situated in the amphibolite facies aureole of the Western Plutonic Complex overprinting the Yellowknife Greenstone Belt. Metamorphic grade of the upright monoclinal basaltic succession decreases from hornblende-amphibolite facies along the border of the batholith to greenschist facies. Metamorphic isograds, subparalleling the faulted margin of the batholith, transect volcanic stratigraphy and coincide with major gold­ bearing shears.Gold mineralization is confined to north-striking, west-dipping shear zones where hanging­ wall amphibolite facies mineral assemblages retrogress to chlorite-carbonate-sericite-sulfide bearing schists hosting multiple generations of quartz-ankerite veins. The gold-producing portions of the Con and Campbell Shears occur where these structures transect an east trending thermal corridor. The corridor is defined by granitic plugs and a number of related breccia bodies, that can be traced outwards from the batholith across the greenstone belt.Prograde reactions of greenstone during amphibolitization effectively liberate fluids that partition metals. With retrograde reactions at shear zones, gold is precipitated with quartz due to the destabilization of sulfide and arsenic complexes. The coupling of regional prograde metamorphic and restricted retrograde metasomatic overprints suggest mineralization is temporally related to emplacement of the Western Plutonic Complex. Economic gold concentrations within the intrusive corridor indicates enhanced metamorphic overprint of hornfelsed greenstones enveloping satellite intru sives peripheral to the main batholith."

Jan 1, 1993

By T. Holmes, S. Davison

"A surge bin at Agrium’s Vanscoy potash operations has been plagued with flow, wear, and corrosion issues since being built in 1967. The culprits? The bin’s carbon-steel construction, geometry, and the resultant funnel-flow pattern are the root causes. An investigation and cost analysis indicated that hopper redesign and retrofit would increase production and reduce maintenance and capital costs. The retrofitted bin provides safer, more reliable operation and has a much longer predicted working life. Using this example, the authors describe bulk-solids-flow theory and highlight the importance of customizing bulk-material-handling-system design using appropriate flow properties to improve reliability, safety, and cost effectiveness.RÉSUMÉ Depuis sa construction en 1967, un réservoir intermédiaire de l’exploitation de potasse Vanscoy d’Agrium connaît des problèmes de débit, d’usure et de corrosion. Les responsables ? La construction en acier ordinaire du réservoir, sa géométrie et la structure de débit en résultant au niveau de la carotte en sont les causes fondamentales. Une étude et une analyse des coûts indiquaient que la restructuration et la rénovation de la trémie permettraient d’augmenter la production et de réduire les coûts d’entretien et en capital. Un réservoir rénové permet de renforcer la sécurité ainsi que la fiabilité de l’exploitation, et sa durée d’activité prévue en est augmentée. En se fondant sur cet exemple, les auteurs de l’article décrivent la théorie du débit de matières solides en vrac et insistent sur l’importance de personnaliser la conception du système de manutention des matériaux en vrac à l’aide de propriétés rhéologiques adaptées afin d’améliorer la fiabilité, la sûreté et la rentabilité.INTRODUCTIONIn early 2013, Agrium’s Vanscoy Potash Operations (VPO) engaged Jenike & Johanson Ltd. (J&J) to provide testing, consulting, and structural engineering services related to proposed modifications to the 270 t special standard product surge bin, which Agrium planned to undertake during a two-week shutdown in August 2013. The bin, which had been plagued with flow, wear, and corrosion issues for its entire working life, was essential for the continuous operation of two of VPO’s compaction plants and for efficient dispatching to loadout. The bin often experienced product hang-ups, clumping on the walls, and plugging at the hopper outlet. Two recent unscheduled mill shutdowns had been partially attributed to flow issues in the bin due to clumping and product plugging up at the screws. These problems increased maintenance costs, limited production capacity, and degraded product quality. Holes and paper-thin sections in the bin walls discovered during a 2013 inspection revealed the potential for major hot material leaks or even structural failure. Either issue would stop plant operations until the bin could be repaired or bypassed. Clearly, the bin cone had reached the end of its life and required replacement."

Jan 1, 2018

By G. S. Hume

Introduction Core drilling of the bituminous sands of northern Alberta has been carried on by the Mines and Geology Branch, Department of Mines and Resources, under the supervision of the Director, W. B. Timm. This was part of the Dominion Government&apos;s wartime investigations, which included an agreement with Abasand Oils, Limited, for the study of commercial possibilities of obtaining oil from the bituminous sands. The drilling programme, commenced in 1942 by the Consolidated Mining and Smelting Company of Canada, was continued in 1943 and subsequently by Boyles Bros. under contract with the Mines and Geology Branch. Several areas have been investigated and one of these, the Mildred-Ruth Lakes area, &apos; herein described, is of special importance in that it contains a sufficiently rich and large deposit of bituminous sands and bitumen beds to warrant consideration of commercial developments for the production of oil. The Steepbank Area, East Side of Athabaska River The Steepbank area, on the east side of Athabaska river in township 92, about twenty-two miles north of Fort McMurray, was selected for drilling in 1942 because previous investigations by Ells indicated it was one of considerable promise both from the standpoint of having reasonably rich bituminous sands under relatively light overburden and also having an excellent tailing disposal and plant site for large-scale operations in proximity to Athabaska river. The drilling done in 1942 and 1943 was largely exploratory, and, when it was found that the southerly part of township 92 had only low-grade material, closer drilling was done in 1944-45 in the richer, more northerly part.

Jan 1, 1947

By Claudia Gasparrini

"Factors affecting the extraction of gold are of a mineralogical nature. Knowledge of the mineralogy of the ore or metallurgical product to be treated, if appropriately combined with the metallurgical test work, may improve gold recoveries. .This paper outlines the mineralogical techniques f or the study of gold ores and metallurgical products and describes the gold mineralogy in relation to its metallurgy. An effective plan for studying refractory and other difficult ores, combining metallurgical test work, chemical analysis and mineralogy and capable of giving positive results over relatively short periods of time, is suggested.IntroductionFactors affecting gold recoveries are of a mineralogical nature and include (i) the gold-bearing minerals, (ii) their grain size and, particularly where the grain size is very fine (10 microns in diameter and less), (iii) their host minerals and (iv) the association these form with the gold-bearing minerals.Mineralogical studies of gold ores and metallurgical products containing gold in economic amounts (today down to 1/10 of one ounce per tonne or 2.84 ppm) are difficult and time consuming. Mostly because of such reason, metallurgical testing (test work) is usually done simply by trial and error without understanding the causes for failure or success.Mineralogical studies, if appropriately conducted and combined with the test work, provide an efficient mean s of improving recoveries through the understanding of gold losses derived from the use of the wrong technique for separation. The information they provide is therefore the first step in the development of recovery techniques, for those ores where the test work alone failed to produce positive results."

Jan 1, 1983

By K. Howard Poulsen

Shear zones are tabular tructures which tend to occur either discordantly within, or concordantly along the margins of, competent rock masse uch as plutons, sill or flows. They contain deformed equivalents of their host rock and are common sites for gold mineralization localized in tructure oriented y tematically relative to the shear zones and internal linear fabric. Apan from genetic implications, hear zone analysis proves useful in exploration for this type of deposit because the zones are generally wider and more continuous than associated mineralization and because there is an element of predictability to mineralization geometry (i.e. vein orientation. plunge).

Jan 1, 1986

By Darren Medd

Kumtor Gold Company (KGC) currently operates the 500,000 tonnes per day Kumtor open pit gold mine located in the Issyk-Kul region of the Kyrgyz Republic at an elevation of more than 4,000 m. To supplement the open-pit mill feed with high grade underground ore from outside the current pit limits, KGC started pre-production design and development of the underground mine for the SB ore zone in late 2006. The initial phase of pre-production development consists of exploration and haulage declines which, upon completion, will provide ventilation and access to the underground mine. Design and construction of these declines presented many challenges to the project team considering the mines unique location at high altitude, the limited experience with Western underground mining techniques in the Kyrgyz Republic, and the impact of the nearby Davydov glacier and resultant ground conditions. Completion of the exploration and haulage declines was undertaken jointly by KGC and mine contractor, J.S. Redpath Limited (Redpath). The initial phase of development including several ground falls provided detailed information on geotechnical ground types and conditions that were useful in determining the overall mine design and methodology for production. This paper covers the various aspects of the design and construction process of developing the declines under the glacier, minimizing the likelihood of further ground falls, and the journey of both KGC and Redpath which led to the successful breakthrough between the declines on 01 July 2012.

Aug 1, 2013

By R. Vracar, D. Sinadinovic, Ž. Kamberovic

The paper presents a study on the oxidation of polymetallic gold ore by oxygen in an autoclave. It presents optimum parameters of autoclave leaching of sulphide refractory ore in self-generated sulphuric acid solutions aiming to get products with favourable technological characteristics from which precious and other useful metals can be recovered. A high partial oxygen pressure (1.5 MPa to 2 MPa), high leaching temperature (190°C to 200°C), pulp density 80 g/L to 240 g/L, ore fraction size 76 µm and leaching time up to 4 hours yield good results in rich ores. The full extent of copper and zinc conversion as well as a high extent of iron conversion has been achieved, while lead, gold and silver and a minor part of iron remain as a solid residue among gangue minerals.

Jan 1, 2001