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By RAYMOND C. HARTVIKSEN

The Drumbo Mine is located near Highway 401 between Woodstock and Kitchener in southwest Ontario. The tabular flat-lying gypsum bed is between 1.5 to 2.4 m thick and is situated near the base of the Salina Formation, about 116 m below surface. The mine is owned and operated by Westroc Industries Limited. The 3.8 m diameter shaft was drilled using a Hughes CSD 820 drilling rig and a liner sinking technique new to the North American continent. The shaft was completed in the fall of 1977, and remaining facilities were finished in the fall of 1978. Gypsum production started in December 1978, employing the conventional room-and-pillar method of mining.

Jan 1, 1984

By A. J. Rigby

Computer generated, actual-scale furnace models have been imported into a rendering software application to provide for impressively realistic surface features and lighting. When these models are imported into a 3D engine framework, it is possible to create content-rich virtual environments allowing for complete interactivity and could provide for a powerful tool to conceptualize refractory lining designs. This technology has been applied to illustrate the optimized design concept of an anode-refining vessel, which can be expected to be completely relined in six days and to last for 4-5 years with minimal partial relining. This technology could easily be applied to other smelter furnace, converter and refining vessel designs.

Jan 1, 2007

By R. von Bonsdorff

Electrochemical and quartz crystal microbalance (QCM) methods were used to investigate the dissolution rate of gold in a solution similar to those utilized by the Outokumpu HydroCopper® process. The measurements were conducted in an electrolyte solution where [NaCl] = 2.8-280 g/L, pH = 1-2.5, [Cu2+] = 0-30 g/L and T = 70-95°C. According to these measurements, the solution flow has the greatest impact on the dissolution rate of gold in the HydroCopper® process. Under adequately acidic conditions (pH < 3), the dissolution rate of gold increases with increasing cupric concentration, increasing chloride concentration and increasing temperature. The results and trends observed compared well with the literature.

Jan 1, 2007

By M. E. Wilson, A. C. Lee

"The property owned by Senator-Rouyn Mines, Limited, is in Rouyn township about 17'2 miles southwest of the town of Rouyn. It adjoins the Chadbourne claims of Noranda Mines, Limited, on the south and the Bagamac property on the ·west. It includes seven claims-block 44, blocks 80 to 83 and blocks 96 and 97; the mine is wholly in blocks 44 and 82.Late in 1936 gold was discovered in an outcrop of rusty weathering carbonate rock near the north end of block 44, and the following year the present Company was organized to proceed with the development of the property. During 1937-38, 17,000 feet of diamond drill core were bored to determine the extent of the ore deposit at depth. From October 15th, 1940, to April 15th, 1941, the ore was hauled to the mill at the Arntfield mine for treatment. The mill on the Senator-Rouyn property started on April 25th, 1941, and has been in practically continuous operation since than time. To the end of 1946, 574,874 tons of ore, from which gold having a value of $3,836,450 was recovered, were treated in the mill.GEOLOGYThe rocks exposed at the Senator-Rouyn mine, except in the southern part of the property, are almost wholly quartz diorite, part of an irregular mass that extends west from the town of Rouyn along the north shore of Noranda lake and thence southwest across the Senator-Rouyn claims. In the northern part of the propertyt inclusions of rhyolite occur here and there in the diorite. In the southern part the predominant rock is dacite and in the east-central part of block 44 claim andesite. Dykes of andesite, quartz syenite, and later diabase also occur on the property.The andesite of the Abitibi volcanics is not exposed on the property, but has been intersected in three diamond drill holes, one on the eastern boundary of block 44 and two farther west within the block. This andesite is probably the western end of a band of pillowed andesite well exposed in the Larose claim to the east."

Jan 1, 1954

By Russell McIntosh

"The Madsen mine is in the southeastern part of Baird township, in Red Lake area, Ontario. It lies about 6 miles southwest of the town of Red Lake, with which it is connected by an all-weather road.The Madsen Red Lake Gold Mines Company was formed in March, 1935, to take over the holdings of the Falcon Gold and Jomac Gold syndicates. During 1935 an4 the early part of 1936 No. 1 shaft was sunk and drifts driven on four levels, all on a narrow quartz vein in a granite dyke.In July, 1936, the Austin zone was discovered about half a mile north of No. 1 shaft by Austin McVeigh, a prospector employed by the Company. Diamond drilling showed that the zone included an orebody worth development, and in 1937 No. 2 shaft was sunk, three levels opened up and sufficient ore outlined to justify the installation of a mill. Milling commenced in August, 1938, at the rate of 300 tons a day, which was later increased to 400 tons a day.The total production from 1938 to 1946 was 1,116,307 tons from which gold and silver having a value of $9,949,010 were recovered. The gold produced ranged from a minimum of 0.1910 oz. a ton in 1939 to a maximum of 0.2827 oz. in 1944. The average grade in 1946 was 0.2345 oz. to the ton."

Jan 1, 1954

By R. Aubertin, G. Panneton, P. Donovan

The Detour Lake gold project is located in northeastern Ontario, approximately 300 km northeast of Timmins, within the Abitibi greenstone belt in the northwestern portion of the Archean Superior Province. Historically this greenstone belt has produced approximately 180 million ounces of gold, largely from narrow vein underground mining. The Detour Lake project is a site of extensive past exploration since 1974, as well as underground and limited open pit mining activity from 1983 to 1999. During this period, it produced 1.8 million ounces of gold. Underground mining focused on narrow vein conventional shrinkage and mechanized longhole stoping. After acquiring the property in January 2007, Detour Gold Corporation initiated a comprehensive drill campaign to define the potential for a large, open pitable, low-grade gold deposit. From 2007 to present, Detour Gold has completed over 500,000 metres of diamond drilling. A technical report completed in March 2011 defined an open pit mineral reserve of 14.9 million ounces of gold, which is Canada&apos;s largest undeveloped gold reserve. The Detour Lake project is currently in development and infrastructure construction of the mine facilities started at year-end 2010, after all the necessary Provincial regulatory permits were received. Gold production is expected to commence in early 2013. Gold mineralization at Detour Lake is associated with a large scale deformation zone (Sunday Lake Deformation Zone; "SLDZ") that occurs at the contact between the 2.72 Ga Deloro Group mafic metavolcanics and the 2.69 Ga Porcupine Assemblage metasedimentary and metavolcanic rocks. The bulk of the gold mineralization is found in the hanging wall of the SLDZ, which is associated with a stockwork of auriferous quartz veins that splay from a flexure along the deformation corridor. The mineralization forms a 200-350 metres wide auriferous corridor defined over 3 kilometres along the strike of the mafic metavolcanic assemblage, from surface to at least 1,000 metres depth. The richest gold mineralized zones are commonly associated with quartz veins with a strong biotite alteration and local zones of pyrrhotite-chalcopyrite-pyrite-gold enrichment formed during the deformation of the quartz vein system.

Jan 1, 2011

By Ian Orford, Ken L. Boyd

"Can the ever-increasing tonnages of ore and waste being mined today be accommodated simply by using bigger and better crushers? This paper updates the principal author’s earlier publication, “Crushing Plant Design and Layout Considerations” (SME Mineral Processing Plant Design, Practise, and Control, 2002). It reviews the latest primary crushing and large cone crusher designs. Its goal is to help consultants and operators select the optimal equipment and custom-designed items in the material handling flowsheet from the mine to the mill, maximizing operating hours per year.INTRODUCTIONAre larger crushers the answer to meeting the demands of existing or new mining projects for increased tonnage? The principal author’s previous paper in the year 2002 on ""Crushing Plant Design and Layout Considerations"" provided a detailed design and layout review for the design of primary and fine crushing (Secondary, Tertiary, Quaternary) mineral processing facilities. Some of the conclusions in this previous paper had predicted that larger crushers for primary and fine crushing would be beneficial and contribute to the further development of mineral processing. Larger crushers for primary and fine crushing applications are now available.The rock size reduction process, from the mine to the selected milling process facility has not changed since man first broke a rock to get at the interesting mineralization within. The rock size reduction process circuit from the mine to the mill can be summarized into four (4) stages:• Stage 1: Mining ( Rock Breakage and Fragmentation)• Stage 2: Pre-Screening (Scalping)• Stage 3: Primary Crushing• Stage 4: Fine Crushing (Secondary, Tertiary and Quaternary; the crushers used in this stage are identified by the titles which usage has conferred on them)Plant throughput and ore delivery schedule will form the basis for flowsheet design and equipment selection. Once a project's design criteria and the mine plan has been established, the actual circuit's utilization percentage (percentage of hours when the circuit is being utilized) can be optimized for each of the four stages. The mining and process departments are the key stake holders in the selection of the final comminution circuit and both departments should be familiar with and contribute to the design of the circuit."

Jan 1, 2016

"In developing a backfill system handling tailings feed to and from the storage silo, it is necessary to establish a slurry laboratory to develop the technology and silo design criteria. This paper presents the principles involved in such development and the importance of testing principles for optimizing the slurry system. Evaluation procedure based on experiments is applicable to a wide range of materials and allows silo design by scaling up the data gained from model tests. Silo simulation has been successful to design and operation, so becomes an effective approach to backfill applications. IntroductionThe silo is a device comprising specialized equipment and operating with related procedures for storing and handling the mill rejects as backfill slurry. It provides a steady supply of the solids slurry, prepared at desired pulp density under the continuous feed conditions. Because the silo system is designed to accomplish specific objectives when dealing with a particular mill tailings slurry, it is necessary to characterize certain slurry properties, behaviour of the solids slurry and understand the silo performance to establish design criteria. Bench-scale, pilot-scale and dewafull- scale experiments were employed in developing the load-storage-discharge system, and routine procedures are now available for pre-design testing. Silo model experiments and full-scale tests were conducted to define the design parameters and evaluate the silo performance. A silo can be designed by scaling up the silo model geometry and data obtained during tests.Since the early 1960s, silo backfill systems have been widely established. The shape and size of the silo and the operation procedure, as practised, all appear to be relevant to successful operation. Understanding the basic material properties and behaviour of solids slurry retained in the silo will help perfect the silo design, operation procedure and, consequently, improve the silo performance."

Jan 1, 1997

By Denis Landry

"RÉSUMÉAu cours de dix dernières années, la compagnie Maghemite a développé, expérimenté et breveté un nouveau precédé de concentration du minerai de fer à partir de la récupération d&apos;hématite présente au bassin de sédimentation de la Compagnie Minière Québec Cartier.A partir de cette nouvelle technologie de concentration par induction, la compagnie Maghemite produit une poudre d&apos;hématite qui est mélangée avec du strontium carbonate à un ratio de l à 6 en poids. Le mélange homogène est achemine sur un disque d&apos;agglomération, et ensuite incorpore dans la fournaise de la Compagnie Minière Québec Cartier. Le temps de cuisson et la température (l200°C) correspondent exactement aux critères nécessaires pour la fabrication d&apos;aimants de céramique, Grade 5, à partir de la poudre de ferrite.IntroductionMeghemite a débuté sa production de poudre de ferrite au printemps 1986et prévoit une production de 20 000 tonnes par année dans cette nouvelle usine. A très court terrne, une usine sera construite pour la production de cinq à dix millions de Iivres d&apos;aimants permanents par annee et à long terme qu&apos;une usine de fabrication par robotique de moteurs à aimants permanents, utilises dans I&apos;industrie automobile. La poudre de ferrite à base de strontium est une compose ferro-magnétique forme d&apos;une molécule d&apos;oxide de strontium et de six molécules d&apos;hernatite. Ce compose d&apos;hexa fluorite de strontium a une force tres puissante et fournit la source d&apos;énergie magnétique la moins dispendieuse comparée aux autres aimants permanents. L&apos;utilisation des aimants de céramique formes d&apos;hexa fluorite de strontium a connu un croissance phenornenale depuis 1970 pour atteindre un marché de 500 millions de livres par année en 1985.II n&apos;y a aucune autre usine de production commerciale de poudre de ferrite à base de strontium au Canada. Le facteur determinant qui a favorise l&apos;etabilissement a Port Cartier est base sur la réduction de 30% du cout des aimants de cerarnique provenant de notre poudre. Notre debouche majeur se situe aux États-Unis et vise la production des aimants de cerarnique pour les moteurs utilises dans les automobiles, les ordinateurs et les appareils ménagers, L&apos;objectif de cette compagnie est de réduire le prix futur des aimants de cerarnique à environ 30% du prix actuel.L&apos;usine commerciale de production de poudre de ferrite est maintenant opérationnelle. Le financement et la construction de cette usine sont Ie résultat de l&apos;opération d&apos;une usine pilote sur une période de 5 ans afin de récupérer l&apos;hematite d&apos;un haut niveau de pureté provenant de résidus de I&apos;usine de bouletage de la Compagnie Minière Québec Cartier (CMQC) à Port Cartier. La fournaise de CMQC est utilisee pour chauffer les boulettes cornposees d&apos;un mélange de carbonate de strontium et d&apos;hematite d&apos;un haut niveau de pureté en étalant environ 5 tonnes à l&apos;heure de ces boulettes au-dessus du tablier de boulettes de fer dans une des fournaises fonctionnant à environ 450 tonnes à l&apos;heure."

Jan 1, 1987

By Guocheng Pan

"Although many factors play roles in the estimation of recoverable reserves, smoothing effect and conditional bias are considered major geostatistical issues in the estimation. This paper introduces measures for smoothing effect and conditional bias, and provides insights into their relation to the estimation of recoverable reserves. Both smoothing effect and conditional bias are intrinsic to the information effect and kriging estimators. For a given level of drilling information, however, it is possible to identify the optimal search radius that minimizes conditional bias. Furthermore, it is also feasible to define variance correction factor for reduction of the smoothing effect from exploration block models. Both of these components are key to the accurate estimation of recoverable reserves. IntroductionThe accurate estimation of recoverable reserves is critical to decision making in different phases of feasibility study and mine planning. Much attention for improving the methodology of estimation has been focussed on the effect of the change-of-support (Parker, 1980; Dagdelen, 1996). For example, it is essential to make a volume- variance correction to the estimate of multiple indicator kriging (Hoerger, 1992). When the size of block, b, in the geostatistical model differs from that of selective mining unit (SMU), v, a volume-variance correction is warranted for the prediction of recoverable reserves.Most mining plans and decisions are made prior to the availability of high density blast-hole samples. In most mining operations, the true SMU grade Zv is unknown at the time of selection. Instead, the selection is based on the estimate Z v**derived from high density blast-hole samples within the deposit G. Nevertheless, the estimate Z v * of recoverable reserves in the stage of mine planning is derived from exploration data. At the end, the production result must be reconciled to the estimate Z v * . In other words, the selection is based on Z v** from blast-hole samples, while the final production figures are reconciled to Z v * from exploration drilling. For a given preselected cutoff grade z0, the actual mining panels will consist of the units having the estimated grade Z v** =z0 rather than the true grade Zv =z0. The difference between Z v** and Zv is usually of less concern."

Jan 1, 1998

By A. H. Lang

THE recent production of important quantities of high-grade muscovite at the Purdy mine, near Eau Claire, Ontario, bas brought that district into prominence and bas added another strategic mineral to the list of Canadian products. The discoveries are thirteen miles west of Mattawa and about two miles north of the Trans-Canada highway and the Canadian Pacific railway. HISTORY Clear mica of low power factor is in considerable demand in Canada and in the United States for war purposes such as radio and telephone condensers, aircraft spark-plugs, radio tubes, and transformers. Some muscovite (white mica) bas been produced in North Carolina and New Hampshire, but the United States trade bas depended largely on importations of muscovite from India and of phlogopite (amber mica) from Madagascar. For many years Canada bas been a substantial producer of phlogopite, but was unable to compete extensively in the United States with importations from abroad. Canadian production of muscovite bas been negligible as no important deposits were known. Ever since the construction of the Canadian Pacific railway, attempts have been made from time to time to mine the pegmatite dykes in and near the Eau Claire area, but, although some feldspar has been mined, no appreciable muscovite was produced. Lace in 1941, J. Purdy and H. MacDonald discovered a dyke containing large crystals of high-grade muscovite from which they are reported to have sold $700 worth of mica. They recorded claims 35974 and 35975 in December, 1941, and claim 36095 in May, 1942.

Jan 1, 1943

By Törbjorn Naarttijärvi, Bengt Ludvig, Agne Rustan

"Falling rock is one of the major causes of serious injuries and deaths in Swedish mines. The research at the Division of Mining and Underground Construction was therefore directed toward controlled blasting in hard intense jointed rock.The project was started with an extensive literature review. Model tests with a new equivalent model material have been initiated to find ways of improving blasting techniques. The result showed that long cracks arise at the perimeter holes when there is a long time delay between adjacent holes. This led to the theoretical development of a new initiation method with ultra short delays (1,5 ms) f or controlled blasting, called ""Cutblasting"".Full-scale tests have been done at LKAB in Malmberget in hard intense jointed magnetite ore. Four different types of perimeter charges have been tested, namely: tube charges, ANFO mixed with plastic beads, detonating cord and linear shaped charges. Three types of initiation of the perimeter holes have been used, conventional (half-second delay detonators), instantaneous and ultra short ""cutblasting initiation"" (1,5 ms delay). The change in rock strength before and after blasting has been studied with bore hole periscope, vibration measurement and ocular observation of the rock surfaces.Thefull-scale tests showed that ""cutblasting"" with detonating cord in the perimeter holes gave the smallest damage to the surrounding rock. A combination of cutblasting initiation and tube charges are anticipated to give an even better result. A new method of controlled blasting using linear-shaped charges has also been tested, however, this charge type needs further development.The full- scale test also showed that the damage which can be seen on the rock surf ace is about the same for different controlled blasting methods but the not-visual-damage zone varies as much as from 0,1 to 0,7 m.A new classification system for controlled blasting regarding the damage to the surrounding rock has been devised."

Jan 1, 1985

By B. J. Morash

"The six mineable coal seams at Quintette Coal Limited (QCL) vary in thickness from 0.75 m to 9.5 m and include waste partings varying from 0.2 m to 4 m thick. They are highly faulted and folded in some areas and dip angles range from horizontal to 90 degrees. Due to this variation in thickness and orientation of the seams, several different mining methods are used to economically recover the coal. The key to QCL&apos;s success depends on the timely collection of detailed geology data and on mine planning which allows selection of the best method of mining to achieve maximum coal recovery with minimum dilution and cost. This paper will describe the various methods of mining employed and the criteria used to select them. IntroductionThe unique challenge in mining at Quintette Coal Limited (QCL) is to extract large quantities of coal and waste, from a complex orebody, with constricted areas for mining and waste disposal. This challenge dictates the mining of as many as four 10 m benches per year, through complicated coal structures, from three separate open pits with a total of 19coal seams. This total is made up of 5 seams at Mesa, 8 seams at Wolverine and 6 seams at Shikano (Fig. 1).Computer-aided mine planning and scheduling is carried out on a routine basis to ensure the prudent selection of methods of mining, to produce plans which ensure delivery of appropriately blended raw coals to the plant, and to coordinate disposal of large quantities of waste.Several methods of mining are applied simultaneously, and as a result coal and waste are released at different rates from twelve to fifteen mining faces. In order to ensure uninterrupted flow of material from excavators and to utilize the truck fleet effectively, a computerized dispatch system is employed.GeologyGenerally, geological conditions can be related to structural (faults and dip angle) and/or stratigraphic (coal seam and interseam waste thickness) sources"

Jan 1, 1988

By L. Nutter, J. Clancy

"Barite is used extensively by the oil and gas well-drilling industry as a weighting agent. It is particularly well suited for drilling mud because of its qualities; it is non-abrasive, heavy, virtually inert chemically, easy to handle and inexpensive compared to other available heavy materials. Increased deep well drilling in Western Canada, and especially in the Arctic regions, could dramatically affect the demand for barite through this decade. Known deposits in northeast British Columbia are possible sources of incremental barite supplies, should the situation develop.IntroductionThe purpose of this report is to examine the opportunities for expanding barite production in British Columbia. Of primary interest will be the relationship between the projected future levels of production and consumption of barite in Western Canada and the extent to which increased domestic production could replace the need for imports in filling any expected supply shortages.After a brief overview of the nature and uses of barite and some of the relevant features of the barite supply industry, the discussion will turn to the supply gap in the Canadian market and the possibilities for import substitution.OverviewBarite is an industrial mineral which is used in large quantities by the oil and gas well-drilling industry. It is often an important component of drilling mud, a fluid circulated continuously in the well during the drilling process to lubricate and cool the drilling apparatus and to contain the high oil and gas pressures found at depth. Barite (BaSO4) is particularly well suited as a weighting agent for drilling mud because it is a heavy (specific gravity to 4.5) inert mineral which is inexpensive in relation to other materials having a high specific gravity. In the on-site use of drilling mud, ground barite is combined with numerous other solid ingredients and chemicals in the form of a slurry. Other advantages of barite include cleanliness, ease in handling and its non-abrasive character (hardness of 3-3.5)."

Jan 1, 1982

By Charle Lawrence, Murray E. Blanchard

"A significant addition to Canada&apos;s commodity export transportation capabilities is being built by Ridley Terminals Inc. on Ridley Island in the Port of Prince Rupert on British Columbia&apos;s north coast.Site preparation began in early 1982. By the end of 1983 the terminal will be receiving coal from two major new mines being developed in B. C.&apos;s massive $2.5 billion northeast coal development.The RTI terminal will have initial capacity to transfer 12 million tonnes of coal a year from railcars to storage and to ships. Capacity will be doubled to 24 million tonnes as market opportunities are developed.The challenge of building this $220-million facility in less than 24 months, the benefits Canada has received from the work the project is generating, and the long-term faith in Canada that this project represents, are all part of the excitement which surrounds the Ridley Terminal and northeast coal developments.RIDLEY TERMINALS INC. (RTI) is building a very significant addition to Canada&apos;s commodity export transportation capabilities. The facility, on Ridley Island at Prince Rupert, on the north coast of British Columbia, is a key link in British Columbia&apos;s northeast coal development which in itself is a massive undertaking involving investment of some $2.5 billion. The entire project is making a substantial contribution to Canada&apos;s economy at a time when such contributions are sorely needed.The development is creating employment, not only in British Columbia where its various parts are being created by mining companies, railways and others, but also across the country where suppliers are manufacturing a wide variety of good s and equipment for the development&apos;s participants.The RTI terminal is no exception. It is a critical cog in this mega project&apos;s large transportation system and its construction is contributing substantially to job creation and to other economic activity, in the Prince Rupert area and in many other parts of British Columbia and the rest of Canada."

Jan 1, 1983

By V. Nudo, R. del Villar, A. R. Laplante

"Fine iron ore recovery from the tails of Les Mines Quebec Cartier was investigated using Reichert trays and spirals. The effect of feed rate, density and splitter setting on the performance of rougher, cleaner and recleaner stages of a 2DS tray assembly was determined using 2- and 3- factorial experimental designs. The tray concentrate, assaying 27% Fe, was further upgraded by spiral to yield a concentrate assaying 55% Fe. Further laboratory scale testing showed this material to be easily upgraded to 65-66% Fe with high Fe recoveries.This paper presents the metallurgical results of the three tray stages. The model used to predict the performance of a full recovery circuit is then described. Simulation results are presented and their reliability assessed. Finally, an economic evaluation of the proposed scavenging circuit is summarized.INTRODUCTIONThe Mount Wright plant (UWP), located near Fermont, Quebec, processes daily 130,000-150,000 tonnes of iron ore assaying between 27 and 33% Fe, to upgrade it with three stages of 44.5 cm pitch GEC spirals to 66% Fe, while rejecting approximately 80,000 tonnes assaying between 6 and 11% Fe (1-3). Heavy liquid separation (at 3. 3 g/mL) of the plus 37 µm fraction (+400 mesh) of the tails reveals that a significant fraction of the iron is in the sink product, below 150 pm (100 mesh), as shown in Table 1. Also shown is the iron grade of the sink and float fractions. The high grade of the fine sink indicates that hematite ls well liberated below 105 µm (150 mesh), as previous studies have shown (4,5). The iron grade of the floats is very low in the fine size range, but increases with increasing size above 105 pm, because of incomplete liberation. Overall, two thirds of the plus 37 µm iron ls in the sink product, which constitutes less than 10% of the total tail."

Jan 1, 1987

By D. MacGREGOR, VERA TUREK

The Badgeley Island quartzite deposir in Georgian Bay is worked by lndusmin Limired and was developed in 1969 to produce a high-qualiry silica for use in rhe ferrosilicon and glass industries. The quartzire is part of the Precambrian Bar River Formarion, and is a generally whire, fine-grained rock containing rhin sericire seams. Primary sedimenrary features wirhin the deposit are bedding and ripple marks. Amphibolite and diabase dykes cur the quarr zire body.

Jan 1, 1984

By Angeles Mendoza Sammet

Based on the analysis of issues associated to conflicts between communities and mining companies in Mexico, this paper suggests actions to make mining more sustainable in Mexico. Interviews with key informants and a revision of documental information available on the internet provided information on 15 cases of conflicts in various parts of the country. The issues varied from incompliance with environmental law to assassination of community members opposing mining. The analysis concludes that mining is not sustainable in Mexico. Both mining companies and the Government of Mexico can make changes to improve sustainability. Mining companies could take a proactive approach and engage in consultation with communities before starting operations. Sharing information with communities on environmental management programs and monitoring results can be a way to start building trust and demonstrate environmental commitments. Companies can implement and evaluate CSR policies to ensure that all staff and contractors are trained on them to reduce and/or prevent corruption and violations of human and indigenous rights. Only 3 of the 15 companies had clear social responsibility policies or sustainability targets, but no reports evaluating them. Complying with the law does not make a project sustainable because of corruption, deficient enforcement, and gaps in legislation. The Government of Mexico should address the following points to make mining more consistent with sustainable development. Update the mining legislation to introduce sustainable development principles and consultation. Incorporate the notion of Free, Prior, Informed Consent (FPIC) for Indigenous People (IP) on all applicable Mexican laws or regulations. The government should not grant concessions on protected areas or indigenous lands without extensive meaningful consultation with the public, IP and land owners. Finally, it is vital to increase SEMARNAT?s capacity to review impact assessment reports and inspect and monitor environmental compliance along the life cycle of projects.

Aug 1, 2013

By P. J. Deveaux, M. J. Kreczmer

The Tartan Lake deposit 12 km northeast of Flin Flon, Manitoba, was discovered in March of 1984 during the investigation of a VLF anomaly. The discovery hole intersected 16.83 metres averaging 21 gm Au/tonne. Since then, 99 holes, over 21,000 metres, have been drilled outlining 419,491 tonnes grading 11.79 gm Au/tonne in a di stinct group of mineralized lenses referred to as the Main Zone. Three other mineralized zones are known on the property but no reserves have been allowed for these, the South , East and Base Line zones. The Main Zone consists of seven parallel, east-west striking, quartz lenses. The lenses dip steeply to the north and plunge steeply west to northwest. Lens number l strikes for 160m and extends vertically to the 90m level. Within th is lens there is a 60m interval of low grade materi al. Lens number 2 is located about 5-l0m within the foo twall of Lens number I. Near surface this lens stri kes for 40m, at 200m level the strike length increases to 200 m. To date the deepest mineralization on Lens 2 has been intersected at a vert ical depth of 527m. Five smaller lenses are located in the foo twall of Lens 2 , containing gold va lues similar to the two main lenses but erratically distributed. The South Zone, located 100m south of the Main Zone, strikes east-west fo r l00m above the 100m level. The East Zone, found 230m east of the Main Zone, strikes fo r 80m and may possibly be an ex tension of the South Zone. The Base Line Zone is located 275m south of the Main Zone. Sporadic, but very significant gold intersections have been obta ined1n all three zones. Gold-bearing quartz-ca rbonate tourmaline veins are generally confined to a silicous crystal tu ff hori zon. The crystal tuff exhi bits fi ve distinct types of alteration: silicification, sericitization, ca rbonati zation, chlorit ization and pyritization. Silicification has resulted in a perasive addition of silica and the generation of multiple quartz veins. Sericiti zation is restricted to the crystal tuff. All rock units are pervasively carbonatized . Ankerite is abundant in the quartz veins and within the shear zones, particul arly those located along the chilled margin of a nearby gabbro-diorite intrusion. Chloritization is widely spread th roughout the rock units, while pyritization fo rms a broad alteration halo associated with the orebody. Sulphide accesso ry minerals associated with the gold , whi ch fo r the most part appears to be free, are chalcopyrite and pyrite. Generally, the higher grade gold values are related to an increased content of sulphides in the qua rtz veins. The average sulphide content in the deposit is less than 5 %.

Jan 1, 1986

By M. E. Stutt, R. H. Rehder

"The mining industry is taking advantage of the increased performance resulting from the use of variable speed A C drives for large motors. This technology provides increased efficiency under the variable speed and torque requirements of such drives as mine hoists, conveyors, and air moving equipment. The technology does introduce voltage spikes on the voltage wave form that stress the insulation system to a greater degree than would occur with a constant voltage source. These voltage spikes must be considered in the design of the insulation system used for these motors.BackgroundHistorically the insulation systems for large AC motors were designed to withstand with reasonable life the voltage stresses of a 60 Hz constant sinusoidal voltage. One of the design tests is a voltage endurance test that requires the application of a 60 Hz voltage from conductor to ground equal to four to five times normal and establishing a time to failure. These higher than normal voltages accelerate the normal aging process by causing extensive partial discharge activity (corona) within the insulation system and the time to failure is a relative indication of insulation life.In addition to the voltage endurance test at 60 Hz, the individual coils are subjected to a surge voltage test to establish the withstand capability of the turn to turn insulation under switching surge conditions. The surge voltage is a fast rise time, 0.2 microsecond to crest value, voltage spike that can be caused by a circuit breaker or contactor closing operation. These voltage spikes can have a crest value of greater than 3.5 times the normal line to ground crest voltage of the normal 60 Hz power supply. The standard withstand test value is thus 3.5 times normal line to ground voltage. Because the voltage surges or spikes occur mainly during start and stop switching conditions, voltage endurance under these conditions has not been a major factor in insulation system design."

Jan 1, 1995