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By Hans de Ruiter

"Delft University of Technology, RWTH Aachen, Helsinki University of Technology and Imperial College established the Federation of European Mineral Programs (FEMP) in 1999 as a legal body to coordinate joint M.Sc. education.By 2003 the number of participating universities in Europe has grown to 9 (in 7 countries) offering 3 different M.Sc. joint programs. Furthermore students from 8 universities in the USA, Canada, Australia and Chile participate through exchange agreements. About 25 companies are associated with FEMP. Further expansion with other clusters of universities is being investigated.So far some 160 students have taken the programs and are working in all parts of the world in a variety of jobs.The European Commission has recently announced the new “Erasmus World” program that will stimulate the offering of joint programs by European universities and offer third-country students and teachers a greater opportunity for mobility and an enhanced European added value. Host European postgraduate courses will be selected for a five-year period. They will receive funding from the Community and a “EU” seal. Around 250 “EU Masters Courses” will be established.The envisaged new Erasmus program and it’s network and operating practices are very similar to those being used by EMC, EMEC and EGEC. Erasmus World therefore offers a great opportunity for further developments with FEMP as the official body.INTRODUCTIONThe current situation in Europe is that globalisation of the supply of mineral resources has caused the larger mining and the manufacturing companies to expand and invest particularly outside Europe. However these industries still have a great significance for the European Union and its members, which means that mineral engineering know-how is still important in the E.U. It was therefore realised in the mid-nineties that is vital to maintain the very high level of knowledge and skill base in mining engineering and mineral technology that currently exists in the E.U., through good and well-balanced education programs."

Jan 1, 2004

By Markus Timusk

This paper describes a research project that focuses on developing a diagnostic routine to assist in decision support for the condition based maintenance of mobile mining equipment subject to unsteady duty. The objective is to develop a general method for initial identification of mechanical faults in machinery operating under non-steady state conditions. The platform to be used for the experimental development and validation of the system is the swing machinery in an electric mining shovel operating in an open pit mining environment. The strategic approach that is proposed for the diagnostic routine will involve using novelty detection augmented by temporal classification.

May 1, 2004

By K. P. Wright

"Twenty-five years ago, there were about thirty-two gold mines operating in Canada; nine of these have been in continuous operation since then and are still operating. Three of these are part of the Dome Group. Operations of these three and of the newer mines in the Group are referred to in discussing process development over the last twenty-five years.Of the Dome Mines Group, Dome Mines Limited, Sigma Mines (Quebec) Limited, Campbell Red Lake Mines Limited, Detour Lake Mine and Kiena Gold Mines Limited, three have been in continuous operation for the last twenty-five years. Dome has operated for seventy-seven years; Sigma about to complete fifty years, and Campbell approaching forty. Overall, milling processes are virtually the same as they were twenty-five years ago. Tota1 go1d production from the three mines has hardly changed; 1960 production, 416,700 ozs. versus 411,300 in 1985. Milling costs have risen by a factor of six or seven and gold price from $35/oz. in 1960 to $322 in 1985.Basic flowsheets are relatively unchanged. Sigma is an all cyanidation mill grinding in cyanide solution; Dome operates gravity concentration and cyanidation; Campbell gravity concentration, flotation, roasting and cyanidation. All three use Merrill-Crowe zinc precipitation.Detour and Kiena are two examples of the major change in gold processing in the last twenty-five years - carbon-in-pulp. This process has brought along with it other changes, such as, carbon stripping and reactivation, electrowinning, and induction furnace melting. Modern mill design with its use of outside thickeners and agitators, bulk handling of reagents, instrumentation, etc., has made a radical change in operating conditions and appearance of the new plants."

Jan 1, 1987

By C. Gosselin, G. M. Payenzo, C. Bazin, M. Desnoyers, G. Chevalier

"ArcelorMittal Mines Canada operates hydraulic classifiers to reduce the silica content of an iron oxide concentrate from 4.5% to less than 1.2% SiO2. Sampling campaigns were conducted to develop a preliminary model for the hydraulic classifier. Results show that iron oxide and quartz are respectively concentrated in the coarse and fine size fractions of the classifier feed. The mineral partition curves in the classifier and the size distribution of the minerals in the feed are used to simulate the classifier operation in order to identify the source of variability observed in the daily plant production data. Results indicate that most of the variation is probably caused by unsteady operating conditions of the classifiers.INTRODUCTION Hydraulic classifiers are a class of gravity separation devices (Wills, 1992) used to classify particles according to their size and specific gravity. Hydraulic classifiers also known as density separators (Hearn, 2002) combine hindered settling and upward flow of water to selectively entrain light particles to an overflow stream. Denser particles settle to an underflow stream. Hydraulic classifiers are used for various purposes ranging from cleaning of coal (Das, Sarkar, & Mehrotra, 2009), recovery of chromite from plant tailings (Kumar, Tripathy, & Rao, 2009) to upgrading iron oxide concentrate (Hearn, 2002). ArcelorMittal Mines Canada operates several hydraulic classifiers to upgrade an iron oxide concentrate by removing fine quartz and other light minerals from hematite that is the main iron oxide mineral. A project was initiated to analyze the operation of the classifier in an attempt to identify the source of the variability in the production results and to assess the potential of increasing iron recovery in the classifier. One possible disturbance for the classifier operation is the change in the classifier feed composition and size distribution, while the other considered disturbance is the operation of the classifier. The paper is divided into five sections. The first section summarizes the ore processing sequence for the production of iron oxide pellets to identify the position of the hydraulic classifier in the process. The second section describes the hydraulic classifier. The third section discusses the sampling campaigns conducted on the hydraulic classifier. The method used to process the data from sampling, the results of the data processing and simulation of the classifier are discussed in the remaining sections."

Jan 1, 2012

By Mehmet Canbazoglu, Kaarlo Haavanlammi, Hannu Laitala

Cobalt is currently a critical metal because of the increasing number of electrical vehicles forecast for production. Copper and zinc are base metals that are used in many everyday applications, including vehicle production. Eti Bakir Co. Mazidagi Phosphate Plants in the Mazidagi district of Mardin, Turkey is a multi-product facility that produces cobalt, copper, and zinc, as well as fertilizers, from the roaster calcine. Roaster off gas is treated in a sulfuric acid plant (SAP) and the acid itself is utilized in fertilizer production. The comminution circuit, roaster, SAP, and calcine leaching process were developed by Outotec and integrated with the fertilizer production process implemented by Eti Bakir A.Ş. This paper describes the hydrometallurgical calcine leaching process used at the plant, with a focus on the oxidative pressure leaching of the cobalt, zinc, and copper-containing calcine. The cold and hot commissioning phases of the pressure leaching autoclave start-up are discussed together with experiences from the ramp-up period. The production processes of the copper cathode and cobalt and zinc-containing salts are also presented together with some of the plant’s operating parameters. INTRODUCTION The ETI Bakir A.S. fertilizer plant, Turkey, is located in Mardin Province near the border with Syria, (Figure 1). The leaching plant project was started in 2012. The purpose of the plant is to separate the valuable metals from the calcine produced by the pyrite roasters, which are used to produce a SO2 containing gas for the new sulfuric acid plant. Fertilizer production requires sulfuric acid, and for this reason a sulfuric acid plant was built; customer already had access to pyrite concentrate, which is used as the roaster feed. During the engineering phase of the roaster and acid plants it was noticed that the roasted calcine contained considerable amounts of valuable metals like cobalt, copper, and zinc. To recover these metals, a calcine leaching process was developed at the Outotec Research Center in Pori, Finland. The main process connections of the Mazidagi site are shown in Figure 2.

Jan 1, 2019

By Zbigniew J. Hladysz

A Deep Underground Science and Engineering Laboratory (DUSEL) is being planned at the site of the former Homestake Gold Mine in Lead, South Dakota, under the sponsorship of the US National Science Foundation (NSF) in cooperation with the US Department of Energy (DOE). This national facility will host a variety of multidisciplinary science and engineering experiments including physics experiments that require shielding from cosmogenic radiation. Geotechnical mapping was performed in 2010 in large excavations of the Davis Campus at the 4850 Level of the former Homestake Mine. LIDAR mapping included laser scanning using a red light laser scanner and 288 Mpixels 360° still camera. The resulting vector map with the photographs digitally draped over the model, was used to create an accurate, virtual model of the excavations. For model verification, the laser scanning was accompanied by surveying and manual mapping of the geology and rock structure. The immediate use of the model was to perform structural analysis and interpretation of geology needed for the design of the DUSEL?s super large excavations. The second round of scanning, after the application of shotcrete to the excavations walls, will be used as a technical blueprint to assess the effectiveness of shotcrete application.

May 1, 2011

By R. Ramírez, N. Aslin, G. Ríos, T. Bravo, A. R. Almansa

Lacy copper has been an on-going concern at Atlantic Copper for at least 10 years and was first reported to Glencore Technology in mid-2010. Over the past 12 years, many of the plates were replaced due to age and general deterioration however; plate passivation and lacy copper issues have persisted. After analyzing all the possible causes of this phenomena, it was found that the problem is caused by a degradation of stainless steel as a consequence of the deposition of Sb oxides. These deposits act as passivating agents of stainless steel, which reduces the density of copper nuclei, causing defective copper deposit, with low thickness and ductility. After doing several tests for reducing/removing the phenomena, the over-riding factor was found to be the anode-cathode overlap. An adequate overlap eliminates the problem of "lacy copper". This was verified during an eight month trial with anodes extended 2.5cm in length. Longer anode not only avoids the appearance of lacy copper, but also recovers cathodes that already have lacy copper. On the other hand polishing of plates only gives rise to a temporary solution that requires on-going polishing, to avoid the re-appearance of lacy copper. INTRODUCTION The electrolytic copper refinery of Atlantic Copper in Huelva (Spain) was commissioned in 1970 with an initial capacity of 40,000 t of cathodes per year. In 1975 the copper refinery was expanded to 108,000 t/year. From 1994 to 1996, a new expansion together with the implementation of ISA permanent cathode technology led to a capacity of 215,000 t/y. Since 1995, a progressive increase in the current density up to 350 A/m2 has been accomplished, which together with an increase in the number of cells from 1,120 to 1,204, has led to the present cathode production capacity of 290,000 t/y A lack of copper deposition in the lower part of the steel permanent cathodes was first reported in 2010. This phenomenon is known as “Lacy copper” because of the appearance of the copper deposit as it can be seen in Figure 1. The occurrence of this phenomena was relatively low and was assumed to be originated by an excessive anode scrapping. Nevertheless, in December 2015 Lacy Copper was observed in a significant amount of copper cathodes giving rise to the following issues: Increased tramp copper – housekeeping and maintenance problems Poor appearance of cathode deposit and untidy looking bundles

Jan 1, 2019

By Nick D. Rose

The importance of structural geology in open pit slope stability is overlooked in many mining operations due to pressures to cut costs and minimize mine personnel. As a result, mine geology staff are often unable to keep up with geological mapping of the pit slopes due to other day to day production oriented tasks. In some instances, key structural controls that contribute to slope instability may not be identified until after a slope instability has initiated, at which time it may be difficult or impossible to delineate these features in the field. Even for small slopes, understanding the engineering and structural geology of the rock mass, as well as the effects of groundwater and blasting practices, are of key importance to slope stability. Two case histories are presented as examples of mining operations that experienced slope instability with little more than anecdotal information about the structural and groundwater conditions encountered during mining. By conducting field reconnaissance, simple slope stability analyses and ongoing slope monitoring, practical remedial measures were implemented, allowing continued safe mining operation.

May 1, 2002

By A. Saigal

A finite element analysis based investigation using DEFORM software was undertaken to model the extrusion of 15% alumina and 15% silicon carbide reinforced aluminum metal matrix composites. The study dealt with predicting the extrusion load as a function of ram displacement and initial billet temperature. The finite element simulation was also used to determine the maximum extrusion load, temperature distribution, maximum temperature, strain rate, velocity and stress distributions in the billet during the hot extrusion process. The constitutive equation used was of the type: Z = E exp(Q RT) = A{sinh(ao-)}" where Z is the Zener-Hollman parameter (temperature compensated strain rate), s is the strain rate, Q is the activation energy, R is the gas constant, T is the absolute temperature, a is the flow stress and A, a and n are constants. Based on the work of Davies et al and McQueen and Konopleva, the values of Q (KJ/mol), a (MPa-1), n and A for aluminum 6061 composites reinforced with 15% alumina and 15% silicon carbide used are 181, 0.024, 4.15 and 1.33x10'2 and 233, 0.052, 2.60 and 1.26xl0'4, respectively. Even though the individual parameters are quite different, it was found that the predicted maximum extrusion load, temperature distribution, maximum temperature, strain rate, velocity and stress distributions are quite similar and differ by no more than 1-2 percent between the two composites indicating that the deformation behavior is primarily controlled by the matrix material and is not a function of the type of reinforcing ceramic particulates.

Jan 1, 2004

By Kyle Selga, Christopher J. Greet

"The Pulp Chemistry Monitor (PCM) has been installed and operated in a number of concentrators in Australasia, and has produced some very interesting results. PCM measures the pH, Eh, dissolved oxygen, temperature and oxygen demand of process streams within a concentrator continuously and in real time.In the example presented in the paper the cleaner feed pulp chemistry is measured, and related back to changes in the mineralogy as well as variations in metallurgical response. For example, a decrease in Eh and dissolved oxygen as well as an increase in the oxygen demand. These changes in the pulp chemistry appear to coincide with increases in the feed grades, probably higher pyrite grades. Further, these variations in pulp chemistry and feed mineralogy have a negative impact on the concentrate grade and recovery.The implication is that if the pulp chemistry is monitored it is possible to predict changes in the mineralogy of the system, and from this the metallurgical response. Further, the changes in pulp chemistry can be used in a control system to counter the changes in mineralogy and maintain the metallurgy.IntroductionIt has long been recognized at a fundamental level that the flotation behaviour of sulphide minerals is dependent on the pH and Eh of the system (for example: Tolun and Kitchener, 1964; Woods, 1976). However, measuring pulp chemical parameters within an operating concentrator has had limited attention. Woodcock and Jones (1970a and b) were among the first to actually collect data from operating plants. Jones and Woodcock (1984) identified some of the chemical complexities of flotation pulps, and noted that most concentrators already operate at high levels of metallurgical performance but there was still considerable scope for improvement. These gains would, in part come from more effective chemical control. In the same volume, Healy (1984) discussed metal ion hydrolysis and precipitation, redox chemistry and how the surface chemistry of sulphide minerals can be influence flotation behaviour. The impact of grinding environment on the pulp chemistry and flotation response of a complex polymetallic sulphide ore is discussed by Forssberg and Subrahmanyam (1993). Their work essentially contrasts the pulp chemical and flotation performance of pulps ground with conventional ferrous grinding media to a fully autogenous system. The data suggested that the reduction or removal of iron hydrolysis contamination from the system could have a positive influence on flotation behaviour, and perhaps the first stage of “controlling” the chemistry of the system should be in the grinding circuit. Grano et al (1995) demonstrated that the collection of pulp, solution and surface chemical data could identify weaknesses within a concentrator, and from these data develop, test and implement solutions that improved the process. Greet et al (2006) showed that the pulp chemical trends observed through primary grinding and rougher flotation circuits of most sulphide flotation concentrators are approximately the same. There are differences in the magnitude of various pulp chemical parameters (pH, Eh, dissolved oxygen, temperature and oxygen demand) as a result of variations in the feed mineralogy and processes employed. Further, it was noted the Eh shifted to more reducing values of the ten days measurements were collected, and this change could be traced to an increase in the iron sulphide content of the feed. Metallurgically, this resulted in an increase in nickel recovery through the recovery of nickeliferous iron sulphides, and a decrease in nickel concentrate grade."

Jan 1, 2016

By A. G. Doll

"Multi-stage crushing plants, including high pressure grinding roll (HPGR) circuits, require more materials handling equipment than SAG and ball mill circuits. A temptation exists to neglect the energy consumption of materials handling when doing desktop comparisons of HPGR versus SAG milling circuits because estimation of materials handling power requirements can demand significant general arrangement drafting that is not available when performing preliminary scoping or ""desktop"" studies.The largest component of materials handling power is consumed by conveyors when lifting material between stages of crushing, meaning that a simple potential energy model can be used to evaluate conveying specific power consumption. This potential energy consumption for conveying can then be factored to provide overall materials handling specific energy consumption suitable for desktop studies of HPGR and other multi-stage crushing circuits. The technique also permits different crushing circuit flowsheets to be evaluated, at a preliminary level, by simply counting the number of times a conveyor must ""lift"" ore from ground level up to a bin or other equipment mounted up high.INTRODUCTIONTrade-off studies of multi-stage crushing plants involving high pressure grinding rolls (HPGRs) versus semi-autogenous grinding (SAG) mill circuits typically focus on the operating cost savings of crushing plants versus the capital cost savings of SAG mill plants. Very high-level (or desktop) studies of this type do not include a great deal of engineering work, meaning that the details (and costs) of ancillary systems are often not captured when doing the comparisons. The more complicated nature of the multistage crushing plants means there are more ancillary systems than a SAG mill plant, risking a skewed analysis of the operating costs, benefiting the HPGR option.One of the ancillary systems that may be overlooked is the more complicated conveying systems inherent in multi-stage crushing plants. Due to the mass of material being handled in large mining operations, these conveyors become a significant portion of the operating costs. A simple way to estimate the specific energy consumption of conveying systems without requiring engineering drawings and a site layout would allow high-level studies to capture this operating cost."

Jan 1, 2015

By Thomas Deschamps

The main objective of this work was to investigate the effect of binder addition on the geochemical properties of surface paste tailings. Nine leaching columns were prepared following different disposal configurations: non-cemented, non-cemented with cemented layers, and cemented .The proportions of cement by total paste weight were between 0 and 1% for a whole column; the maximum amount of cement in a single layer was 2%. The material used was a sulphide-rich tailings coming from a Canadian hard rock polymetallic mine. The columns have been flushed once a week during 30 weeks. The recovered leachates were analyzed for pH, Eh, conductivity, and a wide range of elements. The drainage rates were monitored during the initial disposal as well as after each column flush. The results show that binder addition can improve the whole environmental performances for some of the studied disposal configurations. The disposal configuration consisting of intercalation of three 2% cement paste layers within non-cemented layers (0.66 wt.% of cement for the whole column), and the configuration with 2% cement added only in the two bottom layers (0,44 wt.% of cement for the whole column), showed the best results in terms of water quality and drainage rates.

May 1, 2007

By J. F. Jackson, R. W. Mau

"The first commercial installation in the mineral industry of the ""Verti-Press"" pressure filter was made by Falconbridge Limited at the Strathcona Concentrator to filter copper concentrate. The filtercake produced contains 6 - 7% H2O, an improvement from the 12 - 13% H2O produced by an internal drum filter, at rates of up to 20 t/hr. A novel slurry feed system incorporates a hose pump and a pressurized slurry accumulator.INTRODUCTIONIncreased copper production from Falconbridge Limited operational mines in the Sudbury Area has exceeded the current refinery capacity. A copper concentrate has been produced to overcome this constraint and has been shipped to custom smelters either as a slurry or as a 12 - 13% moisture filtercake utilizing an internal drum filter.With the treatment of the new Deep Copper Zone from the Strathcona Mine, copper concentrate production was forecast in excess of the installed dewatering capacity. The filtercake was too wet to transport by truck and the custom smelter refused to handle this product at the truck unloading site. The filtercake had to be trucked to a rail spur and transloaded into gondola cars. This system was expensive, incurred unaccountable losses and the concentrate was assessed a moisture penalty.To reduce the concentrate moisture content to permit direct shipment by truck, two basic systems were available; vacuum filter followed by a thermal dryer or a pressure filter. Past experience with the high capital and operating costs of dryers led Falconbridge to closely examine the pressure filter alternative.COPPER CONCENTRATE PRODUCTIONThere are two separate circuits at the Strathcona Mill; one treating nickel ore and the other treating copper ore.The rougher concentrates produced by both circuits are conditioned with lime and cyanide before the copper-nickel separation in a flotation columns. The concentrate consisting of cha lcopyrite with mi nor cubanite is very clean as shown in Table I. Currently 50% of the copper in the plant feed reports as copper concentrate, in the past, this has been as high as 70%."

Jan 1, 1990

By T. R. Wildeman

"At the Big Five wetland, which was built to treat drainage from a metal mine, encouraging results have attributed to sulfate reduction. Cu and Zn were reduced to below detection limits of 0.50 mg/L, Fe was reduced by at least 90% to below 3 mg/L, and the pH was raised from below 3 to above 6. The study showed that treatment was primarily through microbial processes within the substrate and that plants were not needed to insure success.Constructed wetlands can be taken through design and proofing stages, and into operations scale in a meaningful time frame for on-line acid drainage remediation. In staged design, laboratory experiments are initiated to determine reasonable substrate materials for remediation of a particular drainage. When a reasonable substrate is found, bench scale experiments are initiated as the next stage in the design. In these studies, removal efficiency, permeability, and flow are analyzed to identify candidate substrate which will support sulfate reduction and be hydraulically reasonable. Using this design method at one site, an acid drainage of pH 2.5 was raised to a pH of above 7. Total heavy metal concentrations in this drainage exceeded 900 mg/L. In the pilot constructed wetland Cu, Zn, and Fe were reduced by 99%.Determining how well these anaerobic cells operate in the winter is done at the pilot plant site in Idaho Springs, CO. It's been found that over the last four winters, those cells that emphasize anaerobic removal within the substrate have operated continuously and effectively the year round. Winter operation is aided by the fact that the water temperature of the acid drainage is always between 14 and 16° C, and the cell can be readily insulated from the cold. Activity of the sulfate reducing bacteria may decrease during the winter. However, it appears that organic complexation of metals helps to maintain low concentrations of metals in the effluent."

Jan 1, 1992

By Steve Cole

"The economic and strategic importance of PGE bearing deposits is fuelling renewed exploration and development efforts in the precious metals mining sector.This paper presents a review of the various techniques used in the processing of PGE bearing ores, from primary benificiation to processing routes for the different flowsheets that have been developed amongst current producers. Recent innovations such as preconcentration of ore using gravity separation, recent trends in flotation circuit design and the development of hydrometallurgical routes for the direct treatment of flotation concentrates without the need for smelting will be discussed. Data from recent projects will be presented to illustrate common characteristics of PGE ores and concentrates.INTRODUCTIONThe six platinum-group elements (PGE): ruthenium, rhodium, palladium, osmium, iridium and platinum, together with gold and silver, are considered to be ""precious"" metals. The recent spike in platinum and palladium prices coupled with the projected increase in demand for the metals has fuelled a spate of exploration and new projects in the PGE sector. Historically primary producers of PGE metals have controlled the flow of information relating to the mining and processing of these ores into the public domain. Very little published information relating to individual operations and processes is available in comparison to the abundant literature relating to other metals.The purpose of this paper is to provide a general overview of the issues relating to the processing of PGE ores. Each topic discussed could easily be the topic of a paper or book and so in many cases only the surface of the topic will be scratched. An attempt has therefore been made to provide as many references as possible.This paper discusses the classification and location of PGE ores, the mineralogical factors that affect recovery of PGE's, methods currently used for recovering PGE's and process trends in PGE metallurgy."

Jan 1, 2002

By Iann Bouchard

Introduction à l?abrasion et l?érosion Avec le temps, tout solide va éroder et user les métaux les plus durs; de plus, la Corrosion va aussi laisser une couche mince et faible d?oxydation qui sera rayée du substrat. Solutions et guide de sélection Les polymères de Henkel Loctite® peuvent: ? Réduire l?abrasion par glissement ? Protège contre les agents corrosifs ? Prévenir la cavitation ? Augmenter l?efficacité ? Réduire la turbulence ? Résister aux hautes températures?

Feb 1, 2008

By Costa

The fly-in-fly-out (FIFO) mining model has significant implications for the industry as it plays an important role in fulfilling the economic, social and workforce needs of the contemporary mining industry. It has increasingly been adopted in countries such as Canada and Australia, but is the current nature of the FIFO model challenging the place women have achieved in the mining workforce? Research in the mining and oil and gas industries reveals that major sources of stress for fly-in-fly-out mining workers are the times of parting and of reunion, the challenges in defining roles within the family, parenting, and conflict between spouses over the use of the leave time and money. So how are women in the industry coping with the FIFO schedules and consequent intermittent relationship with families and partners? How is the mining industry adapting to recruit and maintain female employees in FIFO operations? This paper describes an exploratory study conducted in Canada, which intended to provide some initial insights that might help us answer the questions above. There are several inferences made from this exploratory study. It is clear that FIFO poses significant challenges for both female and male workers. It is largely seen as rigid, extremely challenging for employees with young families and workers who are single mothers, and it is generally incompatible with starting a family and caring for small children. FIFO creates severe stress on relationships and on workers psychological well-being. It seems to be indeed harder for women, since they are often in lower paying positions and therefore have less financial reward for the FIFO lifestyle. On the other hand, FIFO creates the opportunity for young women, including Aboriginal women, to jump-start their careers, as well as opportunities for mature women to work while pursuing other personal interests during their time off. This paper concludes with recommendations to improve the FIFO system in order to increase the ability of mining companies to hire and retain women

May 1, 2006

By Patrick Polk

For many years, sulfuric acid producers all over the world have been forced to meet ever more strict environmental regulations to reduce SO2 emissions. The sulfuric acid industry has implemented new solutions in order to comply with the new lower SO2 emissions target. Haldor Topsoe (Topsoe) has responded to this challenge by continuously improving the range of VK sulfuric acid catalysts and providing tailor-made catalyst solutions to meet the demands of the sulfuric acid producers for lower SO2 emissions. Reducing emissions through catalysis: requires less capital than installing a scrubber, requires no additional process chemicals, generates no waste or by-product to dispose of. In 1996 Topsoe introduced VK69, a cesium-promoted vanadium catalyst, designed for operation in the pass(es) after the intermediate absorption tower in double absorption plants. The high activity of VK69 allows for a more than 50% reduction in SO2 emissions from existing double-absorption plants. Topsoe currently has more than 110 installations of VK69. To comply with the still more stringent regulations being placed on the sulfuric acid industry to lower SO2 emissions, Topsoe has developed a new sulfuric acid catalyst designated VK-701 LEAP5™. This catalyst was introduced to the market in 2010. VK-701 LEAP5™ is based on a novel technology which circumvents the internal transport deficiencies of existing commercial sulfuric acid catalysts and thereby offers exceptionally high activity in strong, SO3 rich gases. Sulfuric acid plants have used this catalyst to meet emissions requirements lower than previously believed possible with a catalyst only solution. This paper will present examples on how to reduce emissions by implementing a tailor-made catalyst solution using VK69 and VK-701 LEAP5™.

Jan 1, 2014

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 Ning Shi

This paper suggests an alternative design approach for an innovative shovel dipper, for use in ground conditions where cutting of virgin ground rather than scooping of blasted material is required. Not only does the new design have an optimized dimension ratio (width:height:depth) and attachment arrangement (angle, position), but also a non-linear pro¯le in 2D and 3D. The approach is based on the simulation of a shovel's duty cycle to verify a pilot dipper model. In order to achieve a realistic simulation that could be used to evaluate a dipper design, the model is e®ectively a descriptor of actual shovel activity under soft ground conditions. The shovel geometry, motion and operation, with an emphasis on digging and dumping kinematics and dynamics are the principal elements of the simulation. The simulation considers a fresh face location, repeating tucking, digging and dumping swing motions within the geometric range of the machine, ending when no more face material remaining within reach without re- positioning. The simulation yields digging force, friction force, trajectory, ¯ll time, ¯ll factor, etc, which may be integrated into two basic considerations: power draw (output) and volume delivered (production), as indicators of dipper performance. The simulation has been used as a tool to modify an existing dipper design, prior to looping further simulation cycles. Ultimately, an optimized or totally-new-concept shape is realized. A prototype dipper as a fractional scale model will be built to verity the performance under actual mining conditions.

May 1, 2004