Search Documents

By I. Nakatsugawa

Chemical conversion coating is a process to create thin oxide/hydroxide film containing several inorganic/organic compounds by way of chemical deposition reaction. In case of the application to Mg mobile electronic housings, the film should possess a good electric conductivity while keeping adequate corrosion resistance and working as a paint base. The use of toxic/hazardous chemicals is strictly prohibited from the environmental aspects. This paper describes the recent trend of conversion coating used for Mg electronic housings and analyzes critically from the point of surface technology. The importance of cleaning process and understanding of surface microstructure are particularly emphasized with several experimental results.

Jan 1, 2006

By D. Moffat

Rio Algom Limited has mined uranium at Elliot Lake, Ontario for 20 years. The production of this energy-generating element results in the need to dispose of low-level radioactive solid wastes and liquid effluents. Because of the wet-temperate climate at Elliot Lake, the liquid effluents are of particular importance. Radium-226 is the isotope which requires most attention, and the current practice for its control is by addition of barium chloride and retention of the resultant precipitates in large settling ponds. Analyses of typical effluents and waste streams are discussed and typical levels of radium-226, thorium-230, thorium-232, thorium-228, lead-2iO, polonium-2iO, and uranium isotopes are presented.

Jan 1, 1979

By W. G. Jeffery

"The mining and mineral industries have been, and remain, a major component of the Canadian economy. There are approximately 560 producing mining establishments of which there are some 130 metal mines and an equal number of non-metal mines, the balance being quarries for stone, sand and gravel. For 17 metals and minerals, Canada ranks within the top five as a world producer. There are 29 metallurgical plants. Employment in mining, smelting and refining was about 150000 in 1990. Mineral production, including coal, is about $20 billion. Exports up to the metal stage amount to $15 billion providing a positive trade balance of some $10 billion.The producing industry has a wide diversity of products. The companies range from small single mining operations to large multinationals. In terms of technology the industry has always been in the forefront of cost-effective practice, either using home-grown innovation or freely importing technology from around the world,The Mining Industry Technology Council (MITEC) makes an annual survey of the exploration and R&D expenditures of the senior mining industry that is the mining companies that are involved in mineral production from their existing mines. It does not include those companies solely involved in exploration using funds raised through equity sales.Table 1 shows the actual R&D and exploration expenditures as a per cent of sales. R&D shows a rising trend since 1988although the drop in value of output due to lower prices must be recognized as contributing to the increase. The point about this compilation is that the mining industry re-invests some 4070 of its sales in both exploration and R&D in order to sustain itself. Exploration for the renewal of metal inventories for future mining is a process unique to mining. It is not classified as R&D, and the necessity for this investment goes unrecognized by those who state that the industry does not do enough R&D."

Jan 1, 1993

By Robert W. Plummer

"This paper describes the use of Geographic Information Systems (GIS) as a tool for mineral exploration by using the Eskay Creek area of northern British Columbia as an example. Data entry, analysis and output are discussed. Examples of some of the capabilities of the technology are presented.The main benefit of the technology is being able to perform complex and sophisticated searches of large and diverse data sets to highlight exploration targets. A GIS is a powerful data management tool that can be used in mineral exploration. It is a computer based system that is designed for the collection, storage and analysis of objects and phenomena where geographic location is an important characteristic. The main function of the GIS is to produce information for the geologist from a variety of sources (geology, geophysics, geochemistry, mineral deposits and so forth) quickly and efficiently. This allows the geologist to examine large amounts of data in a fraction of the time than can be done using conventional manual methods."

Jan 1, 1992

By H. W. Smith, D. Guerin

"This paper describes the development of a dynamic model for a full- scale (64 tonnes/hr) grinding circuit consisting of an open-circuit rod mill feeding a ball mill operating in closed circuit. The object of constructing such a model is to investigate the static and dynamic behaviour of potential control schemes. Model selection, data processing and parameter estimation are discussed, and static and dynamic results of simulations are presented. Conclusions are drawn with regard to the adequacy of the model for such studies, and likely limitations on control of such circuits.IntroductionThe model developed here is intended to represent the grinding behaviour of the grinding circuit at the Lake Dufault division of Falconbridge Copper Mines Ltd. This circuit has been fully described elsewhere. At the time of the work described, the ball mill discharge was fed to a four-cell flotation bank , the tailings of which are combined with the rod mill discharge in the cyclone feed pump sump. As the emphasis in this study is on grinding behaviour, and as only I per cent of cyclone feed material is removed in these cells, no attempt has been made to include flotation behaviour in the simulation. One effect of the presence of flotation cells in the grinding circuit is, however, to necessitate somewhat finer grinding than might otherwise be needed: this will have effects on mill parameters.The paper is organized as follows. First the selection of models is discussed, paying particular attention to the problem of selecting simple, yet adequate, flow models for the mills. Then data gathering is described. The method of deriving mill model parameters is explained, and the results presented. Mass balancing of cyclone data and the determination of cyclone model parameters are described. The linking of the models into a full simulation is outlined, and sta tic and dynamic results presented. Finally, the results are discussed and conclusions drawn ."

Jan 1, 1980

By M. E. Sirkka

"INTRODUCTIONInco Ltd. has ten operating mines in the Sudbury district. Over the last ten years mining methods have changed at Inco with special emphasis on the introduction of bulk mining replacing conventional mechanized cut-and-f ill and undercut-and-fill methods. At the same time, the technology and size of LH D equipment has also progressed to meet the demands of bulk mining. This paper will concentrate on various aspects of the introduction and operation of electric LHD equipment a t Inco Limited, Ontario Division. BackgroundInco Limited received its first electric 2 cu. yd capacity LHD in July 1975 at Creighton Mine. The unit was tested pulling shrinkage stope muck and then was moved to a mechanized cut and- fill complex on 6600 Level. The electric scooptram received quick acceptance from the operators, due to its quiet operation and low heat generation, in a relatively hot operating environment. Although there are only two of these units operating a t present, this initial favourable experience, both in cost and efficiency, led to the development and purchase of electric scooptrams of the 5 cu. yd size. There are currently eleven 5 cu . yd electric LHDs in operation.The most recent development a t Inco is the move to yet larger electric LHDs in the 8 cu. yd size. The first electric ""Eight"" has now been in operation at Copper Cliff South Mine for over a year. This unit has the distinction of being the first one of its kind in service in North America. At the time of writing, there were ten 8 cu. yd electric ma chines operating in Inco's Ontario Division Mines, with three on order."

Jan 1, 1989

By Noel Billette, Jean-Luc Chouinard

"An analysis of the number of industrial injuries shows that the mining sector is particularly affected, since mining is one of the most dangerous industrial activities in Canada. This has led to numerous inquiries, and supports the need for an in-depth study aiming at the identification of factors responsible for these accidents. One possible factor often pointed at is the small crews incentives and this paper presents a scientific approach applied to check a potential link between bonus and accidents at two mining companies located in northwestern Quebec.The data required to do so were the accidents, the salaries and the number of hours worked at each mining site by the hourly paid personnel for the period from June 1979 to January 1982. The analysis of the results derived from the initial information shows different behaviours of the frequency rate vs the bonus rate at these mines. The number of days lost per accident is independent of the bonus rate at both mine sites, as shown by Khisquare tests on contingency tables.IntroductionA wide variety of opinions has been pinpointed by a survey of the literature related to individual or small crew incentives and industrial accidents in sectors of activity where it applies. In addition, various formulae of mining contracts take place in the industry on one part, and statistics from this sector indicate a high accident frequency rate on the other part. These fact s have lead to this scientific investigation which does isolate the direct impact of the bonus on workers' accidents. This study was undertaken with the full support of the Quebec Metal Mining Association.The conclusions of this preliminary phase of the researchproject are presented for two mining complexes in northwestern Quebec. The procedure is somewhat similar to the approach of the Belmoral Commission, with the underlying assumption that bonus has a direct impact on accidents."

Jan 1, 1986

By Marc Lavigne

"The Lac Knife graphite deposit was estimated, as part of a feasibility study, using a geostatistical ore reserve estimation method: ordinary kriging. Based on the geology and its interpretation, the results of a variogram study, and the statistical parameters of the grade distribution of the core samples and the composites through the mineralization, the deposit was divided into three separate zones (west, centre and east), and each of these zones was then analyzed and kriged independently.The geological ore reserve estimation results of ordinary kriging are compared to the results of a conventional method (sections) used previously. The two methods gave almost similar reserve figures. The conventional method provided a +2% estimation for tonnage and + 10% for grade because it ignored the spatial relation between sections and samples, and ordinary kriging gave a more accurate longitudinal definition of the deposit.Finally, the paper concludes with the advantages of proceeding with ordinary kriging, namely: higher flexibility (change of cut-off grade), better deposit resolution and enhanced selectivity for the design of the open pit.IntroductionWithin the context of a complete feasibility study for the Société d' Exploration Minière Mazarin Inc., specialists of the Mines and Geology Division of Roche Ltd., Consulting Group, defined a modelling method appropriate to the graphite deposit of the Lac Knife property near Fennont. Many patterns were considered. Based on the geology of this deposit, the planned mining method, the statistical parameters of grade distribution and the variogram study, the process of reserve estimation retained was to use the ordinary kriging in a selective way. It was required because the geometry of the deposit is such that it was unthinkable to apply ordinary kriging without restrictions.This paper gives a detailed explanation of the observations and interrogations which led to the choice of this ore reserve estimation method, and the calculation procedure itself."

Jan 1, 1991

By John A. Meech

"Oleic acid flotation of Mount Wright thickener underflow tailing material has been shown to be capable of increasing plant recovery by 3%. High levels of oleic acid addition (1.5 kg/t) are required, which limit the economic practicality of the system at this time. Nevertheless, from a technical viewpoint, the process is stable with respect to extreme fluctuations in oleic acid requirements, pulp pH and pulp temperature. Methods to reduce the average consumption of oleic acid need to be found. One technique that merits further testwork uses the ""piggy-back"" principle to float hematite fines with coarsegrained hematite particles.IntroductionWith most large-scale iron mining operations treating specular hematite ores, flotation is not often conside red a necessary processing step. The bulk of the iron minerals can be concentrated by gravity techniques and the generation of fines can be minimized because of the course- grained nature of the mineralization. Nevertheless, production of some fine material is unavoidable, and recovery of iron from this fraction by spirals is poor (10-30%).When the proportion of the iron in these fines becomes excessive, alternative methods to conventional spirals are considered(11), Many of the techniques that have been developed suffer from either poor recovery (e.g. the Reichert cones at 36010 recovery)(11) or low throughput rates (e.g. wet highintensity magnetic separation)(12), Flotation is often passed over because of excessive reagent costs, pollution problems and/or balling difficulties from the reagents used.However, of all the processes available, flotation can yield high recoveries (60-90%) at reasonable throughput rates with excellent process control features (reagent addition and/or cell level). The key parameter is reagent cost.This paper describes testwork on the use of oleic acid to float hematite from the fine fractions of the Mount Wright concentrator tailing. The concentrate product from this plant is directly shipped, so no balling problems exist. As well, oleic acid may be considered a lesser pollution hazard than many of the cationic collectors used in other iron ore flotation systems. A reduction in fine hematite slimes discharged as tailing into lakes may also reduce environmental damage."

Jan 1, 1981

By G. W. Davies

"IntroductionThe development of British Columbia's northeast coal deposits, represents the single biggest industrial undertaking in British Columbia's history.As a result of this development, several thousand jobs were created, hundreds of millions of dollars in new tax revenue and billions of dollars in new foreign exchange began flowing into Canada.The Northeast Coal Development began in 1981 with the signing of sales contracts to ship a total of 6.5 million tonnes of metallurgical and additional quantities of thermal coal annually to Japan over a 15-year period. The current long-term agreements contain provisions for extension to 20 years.The sales contracts with a group of Japanese steel mills were signed by two Vancouver-based mining companies, Quintette Coal Limited and Teck Corporation. The agreements followed years of exploration and negotiation beginning in 1968.The first shipment of coal from Quintette and Teck's Bullrnoose Mine was transported by BC Rail and Canadian National Railways to the Ridley Island coal port in the fall of 1983."

Jan 1, 1992

By Marcel Allard

On January 1st, 1977, SIDBEC-NORMINES INC. purchased from Quebec Cartier Mining Company various facilities located at Gagnon and Lac Jeannine together with the Fire Lake deposit. A t the same time, SIDBEC-NORMINES started its mining operations at Fire Lake, 83 km northeast of Gagnon. The paper summarizes the various adjustments which were necessary to satisfy the new production conditions, such as the physical and mechanical properties of the ore at Fire Lake, and the new crushing and loading installations at the mine, together with the transport of some 14 million tons of crude ore to the Lac Jeannine concentrator about 100km away, and finally to achieve satisfactory recovery from the FireLake ore. In addition, mention is made of the manpower organization, in which Quebec Cartier Mining Company plays an important role as manager of operations and owner of the railroad linking the mining operations to the pelletizing operations at Port-Cartier.

Jan 1, 1979

By T. P. Kostek

"Historically, gear pumps and motors have been popular in the mining industry because of their competitive cost, simple yet rugged construction, ease of rebuild, and relative long life and insensitivity to contamination. However, with the ever increasing ""popularity"" of fire-resistant hydraulic fluids, both users and manufacturers of gear equipment must make special considerations to enable the equipment to continue giving satisfactory performance even with the water-containing fluids.The paper discusses 60-40 invert emulsions and waterglycolsIntroductionMuch information has been published on the specific characteristics of the various types of fire-resistant hydraulic fluids. Fluid manufacturers' literature and other publications have dealt with such specifics as fire resistivity, seal compatibility and wear rate characteristics. Gear pumps and motors have been, and will continue to be, applied successfully in hydraulic systems employing both the ""invert"" emulsions (60-40) and water-glycols as the hydraulic fluid.Because most external spur gear equipment has been designed to function with petroleum oil as the fluid medium, certain guidelines must be followed to ensure satisfactory service life. FluidsThere are a number of different types of fluids which fall in the category of"" fire-resistant"" , the most common'being phosphate esters, water-in-oil emulsions, oil-in-water emulsions and water-glycols. The two in most prevalent use today as hydraulic fluids are the water-in-oil emulsions and the water glycols"

Jan 1, 1980

By Robert B. Parsons

"Once all the hullabaloo about Finance Minister Wilson's April 27 budget died down (or was it an April 26 budget?), the pain of the budget papers began to sink in. Individuals and corporations will have to dig deeper and pay more taxes - and government will continue to dig deeper and spend more. The irony of the situation is that higher tax rates actually make flow-through shares more attractive as a tax-deferral investment - a bittersweet ""bravo"" for the mining industry.INTRODUCTIONFor the first time in Canadian history, a major budget address has taken two days to deliver. Of course, it's not a case of long-windedness, but rather a case of a hastily called press announcement on April 26 in response to a budget leak, followed by a formal budget speech on April 27.The general reaction of the business community to the budget was to the effect that the tax hikes are acceptable, but the government's failure to curb spending is less than acceptable. Mr. Wilson's reported response indicated that the government had never promised to cut spending, and that increased government spending would actually benefit the country. That age-old debate will doubtlessly continue for generations.In any event, three noteworthy components of the budget papers are:• Personal income tax rates increase effective July I, 1989;• A ""large corporations tax"" (in effect 'a corporate ""minimum tax"") is effective July I, 1989; and• Federal sales tax increases are effective from June 30, 1989, to be replaced by a national sales tax in 1991.A brief overview of these and other budget proposals follows."

Jan 1, 1989

By Doug Ashbury

Diamond Miners? Challenges ? Remote ? 300 kilometres from Yellowknife ? Sub-Arctic conditions ? permafrost, climate ? No power ? No all-weather roads ? Ore bodies difficult to find ? Caribou, fish of special concern ? Communities with low education, little experience, but high expectations ? Major investment required ? Diavik C$1.3 billion

Apr 1, 2005

By Jacek Paraszczak

Possibility to move human workers away from dangerous places ?enhanced safety and improved working environment; ? Increase of actual operational time: ? Less losses due to shift changes, regulatory breaks, blasting periods, ventilation after blasting, etc.; ? Possibility to work in extremely dangerous conditions where man-operated machine could not be used (for example: ST-14 loader in backfilling operations in the Kemimine, following roof collapse). Reduction of the production cost through: ? Lower maintenance cost (less damage due to operator?s mistakes and no machine abuse); ? Higher productivity and effectiveness of the equipment (less machines to meet production targets, less operators required, lesser maintenance cost...). ? Although personnel health and safety are key drivers behind autonomous operation of mobile equipment in U/G mines, with significant capital and operation costs one expects to achieve: ? Productivity higher, or at least equal to that offered by man-operated equipment and systems; ? Lower production cost. Therefore, high effectiveness of the autonomous equipment is crucial to succeed.

May 1, 2010

By T. L. Carpenter

"The presence of excessive water in the Gibraltar East Stage 1 pit initiated studies into the ground-water conditions that might be expected in mining the Granite Lake and Pollyanna pits. Hydrologic information obtained from a pump test program in 1974 indicated that deep-well dewatering could be successfully achieved. In 1976, a deep-well dewatering system consisting of eight wells was installed on the periphery of the Pollyanna pit . it has been responsible for a significant decrease in mining costs.This paper presents a brief summary of the engineering principles involved in the design of the Gibraltar dewatering system and the problems encountered in the installation and operation of deep-well pumps. IntroductionGibraltar Mines is an open-pit copper-molybdenite mine located approximately 230 air miles north of Vancouver in the central interior of British Columbia (Fig. I). The property consists of three separate major orebodies; Gibraltar East, Granite Lake and Pollyanna (Fig. 2). Mining commenced during the summer of 1971, in the Gibraltar East Stage 1 pit. The Granite Lake Stage 1 pit was mined from mid 1974 to mid 1976. The Pollyanna Stage 1 pit is currently being mined and the Gibraltar East Stage 2 is being developed for production. This report is intended as an outline of the studies and tests leading up to and including the installation of the Pollyanna pit dewatering system, the problems encountered and the results obtained.GeneralIn the summer of 1973, mining in the Gibraltar East pit progressed below ""daylight"" on the down-hill side and ground water very quickly became a costly nuisance in the day-to-day mining operations. Mining, maintenance and blasting costs reflected these problems. Concern was also voiced about adverse effects of ground water on pit wall stability. This concern later became a reality in the Gibraltar East and Granite Lake pits. A study was initiated to investigate various methods and costs of dewatering the pit areas. The study included in-pit sumps, deep peripheral wells and a drainage gallery system located below the pits."

Jan 1, 1980

By Mario Giavani

"IntroductionBy the 1980s, the continuous casting process had almost replaced the ingot casting of steel in Japan, Europe and North America. While economic benefits were probably initially the prime motivator, the transition rapidly proved that continuous casting in conjunction with ladle metallurgy offered a much greater degree of process control and made possible routine steel specifications not previously available.This new technology demanded improved procedures for the quantitative addition of the required metallurgical reagents, especially as regards the more volatile or toxic elements such as calcium , boron, carbon, sulphur, lead and tellurium. The injection of a thin steel tube containing the additive into the metal bath of a ladle refining station offers the best procedure for this. In the industry this has been referred to as ""Cored Wire "".Operators using this technology find that they are faced with balancing the injection speed against the small cross section of the tube to feed the required amount of reagent within the short time span available to the operation. Large-ladle shops requiring major quantities usually resort to multiple machines and high speeds. Many machines approach a maximum feed rate of 400 m/min. Higher speeds exceed the melting rate of the system, and the ferro static buoyancy of the tube will cause it to coil up the ladle wall and possibly resurface into the slag layer, and even eject itself above the surface. Under these conditions, exact control of element recovery becomes difficult, especially with the commonest addition, calcium silicon alloy.Many experts are persuaded that the final melting position of the carrier tube has major importance in establishing consistent element yield to the bath.For instance, the vapour pressure of calcium at l500 °C is close to I bar. Reaching a melting depth sufficient to accommodate this value is considered to be critical to achieving an acceptable and reproducible yield.Many studies have elaborated semi-empirical formulae to establish the melt zone depth, connecting this value essentially to the diameter of the tube , the injection rate and the superheat of the steel. The author's experience in steelmaking could not confirm such formulae in many cases, and he set about to develop a mathematical model which would be useful in addressing this problem, taking into account the several parameters which will regulate the behaviour of a filled tube immersed in molten steel."

Jan 1, 1991

By Gerhard Melcher, Hermann Hilbrans, Michael Gamroth

"IntroductionSeveral new smelting processes have been proposed and developed during the last 20 years. This has been true, in particular, for copper smelting technology. The important impulses for the advances in this field have been the recent demands regarding the environmental protection, energy saving and improved utilization of the metals contents of deposits, in particular that of complex raw materials.The methods developed more recently for pursuing these objectives have been outlined in several papers. In some of them the advantages and drawbacks of certain developments have been stressed. These documents are of great importance for assessing the different processes. The following paper tries to explain some details of the cyclone smelting process taking into consideration a few of these well-known presentations. The effectiveness of operation of the cyclone smelting process indicates that this process presents a significant achievement when compared with other conventional methods.The application of the CONTOP smelting cyclone range s beyond the field of copper metallurgy or the smelting of sulphide concentrates with the aid of oxygen. The research work carried out in the pilot plant of KHD Humboldt Wedag AG in Cologne-Porz also includes the recovery of the metal contents of intermediate products and processing of smelter residues which have to be converted in a disposable stat e, free of environmental pollution. This paper explains a few examples in this regard."

Jan 1, 1987

By Deni Lessard, Roger Demers, Noël R. Billette

"The Quebec Mining Association has for many years been supportive of the activities of the Centre de recherches minérales which were initiated to ensure regular production hoist and cable inspections to maintain safety and productivity standards in underground mines in Quebec. CRM and CANMET have agreed to fund a Quebec Mineral Development Agreement contract to capture this accumulated knowledge. Using VP-EXPERT to process the information and subdirectories to store regulations, the prototype access D-BASE III records on hoist information and LOTUS 123for simulating working conditions that meet local regulations and expert rules of thumb criteria. Objectives are to improve safety in emergency operating procedures, maximize hoist productivity and safety, and promote knowledge transfer to operators."

Jan 1, 1992

By V. K. Karra

"A simplistic algorithm jar simulating the rod or ball mill Bond grindability test applied to ores and minerals is presented. A performance comparison between the present algorithm and a previously published algorithm by Kapurot, modified in this work jar a fair evaluation, is also given. A worked example is furnished jar leading the reader through the various calculations.IntroductionThe Bond grindability test is widely used for the prediction of the power requirement of an industrial grinding mill. The procedures for conducting this test in either a ball or a rod mill are available(1). In the case of a ball mill, batch grind abilities have been correlated to Bond grindabilities to help monitor day-today variations in ore grindability for the purpose of plant control( 2,3). Of special interest is the algorithm presented by Kapur(3) for the simulation of the Bond test. In practice, the test lasts from 6 to 14 cycles (4 to 10 hours). With this algorithm, one can predict the Bond grind ability using information available from only the first two cycles.Sometimes the prepared feed for the grindability test contains too much fines compared to the total product desired at the mesh of grind under consideration. In such a case, the operator separates the fines from the test feed and adds to the remaining coarse fraction an equal amount of fresh feed. This combined feed then forms the feed to the first cycle of the test. In the present work, Kapur's algorithm is modified to include this special case. A new and relatively simpler algorithm is also presented. Statistical equations relating work index to pertinent variables are also given."

Jan 1, 1981