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By C. J. Kerr

"A recent information sheet from the Mining Health and Safety Branch of the Ontario Ministry of Labour was sent to all Ministry inspectors and engineers. The subject title was' 'Two Brakes on a Hoist Carrying Persons"" and it quotes mining regulation 699, sub-section 206(i):No hoist shall be used for the transporting of persons unless it has a braking system consisting of at least two sets of mechanical brakes to stop and hold the drum for the shaft conveyance transporting the persons.The intent of the regulation is that each of these brakes is to be set so that, individually, they can safely stop the drum carrying persons and also hold the drum without movement with the maximum manload.This can be achieved in the following ways: Single Drum Hoist-one brake on each side of the drum, one brake on the drum, one brake on the pinion shaft, where disc brakes are used two separate disc brake assemblies on the disc. Double Drum Hoist, brakes on companion drum can serve as backup brake only pinion brake with one drum unclutched.Friction Hoist, one brake on each side of drum As new hoists can be manufactured easily with a two-brake system, attention will be focused on retrofitting pinion brakes to older hoists.A brake mounted on a pinion shaft is designed purely as an emergency brake in the event of main brake failure , controls malfunction, and power loss."

Jan 1, 1989

By R. J. Mitchell

"Centrifuge modelling of earth structures is a well-proven technique for evaluating the performance of prototype structures using physical models. The applications of this technique have increased dramatically during the last decade such that even the modelling of dynamic responses in structures has been accomplished.This paper presents the first model test results used to design a mine backfill. The models were tested using a 3 m radius 30 g-tonne geotechnical centrifuge which was constructed at Queen's University specifically for model studies on mine backfill stability and subsidence. The models represent the first production blast-hole stope to be mined at Westmin Resources Ltd. 's H. ~ Mine on Vancouver Island. This paper includes photographs of:model failures in the centrifuge and correlations of model test results with analyses based on unconfined and triaxial test data.IntroductionDuring the feasibility study and development stages for the H.W. Mine, Westmin Resources Ltd. conducted a comprehensive rock mechanics and backfill engineering program. The results of these studies indicated the need for assurance of backfill stability during pillar recovery on the initial blast-hole mining block. The cemented tailings backfill had to be free standing for heights up to 25 m and the potential for surcharge loading from a weak hanging wall zone, the potential for fill block sliding down-dip and the potential for seismic loading had to be considered in the design of the fill strength. The basic questions to be answered were: what cement content is required and will the resulting backfill costs be economic relative to the proposed mining method and sequence? Figure I shows a typical cross-section through the first mining block . The up-dip stope is to be mined first and backfilled with cemented tailings . The down-dip stope would then be mined and filled. Depending on ground conditions encountered, the complete intervening pillar could be recovered and the void backfilled with uncemented tailings or it could be recovered in small sections by exposing limited back and wall areas, backfilling with waste rock and I or cemented tailings . This latter method is commonly referred to as the Avoca method"

Jan 1, 1987

By Derek Harvey

"The paper briefly describes the development of the Eickhoff ESA60 roadcutter which is based on the old and well used principles of the shearer loader. It is intended to show that the machine offers a viable alternative to the normal methods used for driving roadways and also for coal production . References are made to installations currently operating in Europe with applications ranging from roadway drivage to pillar recovery. The paper also looks at possible applications in Canada.IntroductionThis paper is an attempt to show how the principles used in mechanical cutting, conveying and roof support are being applied to a development system capable of catering to a variety of situations and conditions. It is also intended to illustrate how the same system can be used as a total mining system for the mining of many minerals.In order to give some sort of time perspective to the age of the principles, reference can be made to an article in Coal Mining & Processing which states:- During World War II the Germans developed the "" panzer"" or armoured face conveyor.- After the war the English developed power cutters or trepanners that were mounted on the face conveyor, this then developed into the shearer.- The first shearer was produced by the Anderson Company in England in 1950 and shortly after that the Eickhoff Company started manufacturing shearers in German y.- The first hydraulic roof support was produced in 1954 by Gullick.This is a potted history of the three major components of the new system, i.e.:- Mechanical cutting element based on the shearer.- Transport element based on the panzer.- Optional roof support based on the hydraulic face supports.It can therefore be said that since the "" youngest"" of the elements was produced in 1954 the principles of the system in respect of the rapid change in mining equipment are in fact old.Of the three major components the most important is the cutting element since the major benefits of the system are to be obtained from this."

Jan 1, 1985

By Sylvie Poirier

This paper focuses on new developments regarding thermal rock fragmentation applications. The technology consists in a strong burner powered by diesel fuel and air. The thermal reaction, which is created, allows for the enlargement of 125-mm to 450-mm holes by breaking the rock in a spalling effect. It has been used for over 30 years in Russian open pit mining. Following an agreement between Dynamitage T.C.G. Inc. and the owner of the technology, major improvements have been brought to this technology, allowing for the fabrication of a prototype suitable for the Canadian industry. In Russia and Ukraine, thermal rock fragmentation is actually used to drill large diameter holes in surface mining. Upon having acquired a better knowledge of this technology, it seems that it presents a great potential for selective mining in narrow-vein operations, for either surface or underground mining. Rocmec International Inc., a subsidiary of Dynamitage T.C.G. Inc., and Natural Resources Canada are technical partners in the evaluation of the operational parameters and environmental aspects, such as gas, heat, dust and fog emissions. Furthermore, Canada Economic Development is a financial partner in this project. This paper presents the technology and its history. It also reports on the changes brought to the equipment to adapt it to North American environments. A summary of the tests realized since 1995 is provided, along with the main conclusions obtained. The anticipated applications for the use of this technology in both surface and underground environments are described, such as open pit mining, bulk sampling and narrow-vein ore extraction. An estimate showing a comparison between the thermal fragmentation mining concept and the long-hole mining method is presented and, finally, the future developments planned are listed.

May 1, 2002

By A. I. A. Salama, M. W. Mikhail, R. J. Mikula

"The Coal Research Laboratory (CRL) of CANMET along with other research organizations in coal-producing countries envisage major benefits from computer applications in coal preparation, Some of these benefits are greater system flexibility, improved coal preparation plant performance efficiency and efficient utilization of manpower, all of which result in economic benefits. Computers can be applied for both on-line and off-line purposes; this paper focuses on the on-line applications from the process control point of view.A critical discussion of the different analog and digital process control systems is presented. Recent developments in Great Britain, West Germany, Poland and Australia on automation and instrumentation using on-line measurements of coal ash and moisture contents are identified.The CRL research and development strategy aimed at achieving on-line computer control of an automated coal preparation plant is presented.IntroductionIn the past twenty years an enormous progress in the area of computer technology has been noticed. Computer applications in industrial processes offer greater system flexibility, improved plant performance efficiency and efficient utilization of manpower. Significant computer control development in mineral processing has already been achieved. Although progress has been made in the area of computer applications in coal preparation, more effort is needed to utilize the full potential.The computer applications in coal preparation can be viewed as off-line and on-line. Considerable progress has been reported in the area of off-line computer applications, especially in the areas of modelling, performance evaluation/prediction and statistical analysis. However, only modest progress in on-line applications has been reported(1-7). This paper will focus on: online instrumentation and process control applications, different analog and/or digital control systems, on-line automation and instrumentation in other countries and CRL strategy toward pilot plant automation."

Jan 1, 1985

By M. W. Mikhail, R. J. Mikula

"Funding has been made available through the National Energy Program to build a mobile fine coal treatment plant. The plant is intended f or field application and also to upgrade the existing pilot plant facilities.Western Canadian coals with high proportions of fines (due 10 their friability) cause high losses of fine coal to the reject and in turn reduce the over-all recovery of saleable coal. Eastern Canadian coals with high amounts of sulphur of ten require crushing to fin e sizes to liberate pyrite and therefore need effective and efficient separation of these fine sulphur particles. The difficulties involved in solving these problems are two-fold. One is the reluctance to experiment in an operating wash plant and the other is that laboratory scale testing often cannot be extrapolated to the plant environment. The mobile fine cleaning plant with its ability to operate at existing coal preparation plants across Canada and with its flexibility in implementing flowsheet option s and close monitoring of fine coal circuit variables, is ideally suited to solve these fine coal cleaning problems. The mobile plant objectives are to design and optimize flowsheets, evaluate and improve fine cleaning circuit operations and 10 lest new process monitoring and control equipment.The schedule for construction and the required resources will be outlined along with flowsheet options and the general R&D philosophy of the mobile plant.IntroductionIn relation to coal preparation technology, Canadian coal s can be grouped as Eastern coal, Rocky Mountain metallurgical coal and Foothills high volatile bituminous coal. The eastern coals have high sulphur contents and in some cases require crushing or even grinding to liberate the fine pyrite . Rocky Mountain metallurgical coals often occur in highly sheared seams which have been subjected to rapid coalification. The high friability of these coals means that degradation during mining, handling and processing is extensive and results in large amounts of fine s ranging between 20 and 60% by mass of the wash plant feed. The widely varying geo logical structure and exposure to the elements results in partially oxidized coals which perform inconsistently in the traditional method of fine cleaning by flotation . Foothills high volatile bituminous coals for thermal use are frequently interbedded with soft shales and bentonitic clays. These clays disintegrate during washing and swell, producing large volumes of tailings. The presence of clays in plant circuits, particularly fine circuits, tends to increase the viscosity and may cause deterioration of the fines density separation and increase magnetite losses. In view of the fact that fine coal cleaning is the most difficult aspect of coal preparation , a research program is being established to study the factors involved and to offer some solutions.A recent performance evaluation of Canadian washeries showed that yield losses in the minus 2 mm coal circuits were approximately ten times those occurring in the coarse coal circuits(1). Because 2 mm x 0 coal represents 30 to 70 per cent of the raw coal, these losses can be considerable . The operating and capital costs of beneficiating minus 6 mm coal are about four to five times higher than for plus 6 mm coal. In the case o f minus 2 mm coal the costs are even higher. The economic importance of the fine coal cleaning cannot be over emphasized and as a result, the CANMET R&D program is geared for fine coal beneficiation."

Jan 1, 1984

By Chenming Liu, Xiao Lin, Bo Wang, Hongbin Cao, Xingang Li

Over 2 million tons of NH3-N were discharged in China per year recently, rare earth industry contributed 7.03% of NH3-N pollutant from industrial wastewater in 2007. Wastewater containing NH3-N and heavy metals mainly produced in RE extraction saponificated with ammonia and precipitated by ammonia bicarbonate. Generally, 1 ton REO cost 0.6-1.2 ton ammonia for extraction and 1.6 ton ammonia bicarbonate for precipitation, and produce 35-100 ton wastewater. Processes, like Na-saponificated, Ca-saponificated and Non-saponificated technique, are widely studied to reduce the adverse environmental effect of RE industry, while traditional processes still have advantage in production cost, process stability and product quality. In this study, a novel process that combines distillation and air-stripping is developed. NH3-N is removed and recovered based on relative volatility difference of NH3 and H2O. Phase equilibrium, heat equilibrium are calculated to determine process parameters. Hydrodynamic performance like flow field distribution is also simulated. Then, design parameters for distillation trays or structured packing are determined based on calculations and simulations. Besides, the phase diagram of (NH4)2SO4-NH4Cl-H2O in 30°C - 100°C, the typical salts composition of nonferrous wastewater, is studied to ensure commercial plants’ continuous operation. Ammonia removal tower (ART) with different high efficient column internals is designed to fit RE wastewater treatment requirement. The novel process has been commercialized in RE industry in Jiangxi, China. The commercial project operation results show the novel process reached a nearly zero-emission with >99.5% NH3-N was removed and then recovered as ammonia. Combined the novel process, the traditional REO separation process using ammonia and ammonia bicarbonate could achieve NH3-N reuse and the effluent quality meets the discharge standards.

Jan 1, 2016

?Podolsky Water treatment plant discharges to Norman North bog which drains into Whistle / Post Creek watershed and into Wanapitei Lake ?Whistle Mine closed and reclaimed but continues to treat and discharge water to Whistle Creek

May 1, 2009

By P. J. Urso

"This paper discusses the mining problems encountered at the Fording River coal mine to date, and how they have been solved. All of the production now comes from surface mining, but underground hydraulic mining is planned and briefly described. Other facets of the operation, including markets, equipment and personnel, are covered. IntroductionFording Coal Limited was formed in 1968 to mine and market metallurgical coal resources held by the company in the East Kootenay region of southeastern British Columbia. The company, at its Fording River operations, holds approximately 48,000 acres of coal lands, having an estimated 2.0 to 3.0 billion long tons of metallurgical coal in place. (Although not a point for further discuss ion in this paper, the company also holds approximately 1.0 million acres of mineral rights. These consist primarily of coal in Alberta, potash and coal in Saskatchewan, and minor industrial mineral holdings of limestone, salt and bentonite in the three western provinces.)Fording Coal is owned 60% by Canadian Pacific Investments Ltd. and 40% by Cominco Ltd. Inasmuch as Cominco itself is owned approximately 54% by CPI, it is seen that the effective CPI ownership of Fording is about 82%. The company, originally staffed and managed by Cominco, has been independent since January, 1978, with its own board of directors, management, staff and employees.The company's head office is in Calgary, Alberta. The Fording River operations are located approximately 45 miles north of the Crowsnest Pass, near the Alberta/British Columbia boundary, only 95 air miles and 200 road miles from Calgary.A contract was signed in 1969 with the Japanese steel mills to provide 45 million long tons of metallurgical coal over IS years, commencing in 1972 at an annual rate of 3 million long tons per year. Despite some start- up difficulties, the mine and plant facilities achieved their rated capacities in 1975, producing and shipping at the 3-million-Iong-ton level. The coal specifications are shown in Table I."

Jan 1, 1980

By Yu. V. Ponomarenko, A. I. Meka, P. A. Witherspoon, Yu. I. Volkov, J. E. Gale

"The mining of iron ore in the Kursk Magnetic Anomaly (KMA) region of the U.S.S.R. is done mostly by the open-cut method. An assembly of open pits capable of producing about 100 million tons of ore per year makes KMA the largest iron ore field in the world. Three gigantic open pits are currently in operation: Lebedinsky, Mikhailovsky and Stoilensky. These pits are as large as 13 km2 on the surface and as deep as 230 m. The mining operations are constantly faced with the problem of flooding from aquifers that overlie the orebodies; the magnitude of the problem is evident from the fact that the present groundwater inflow to these three pits is about 110 million mt /yr.Under such conditions, safe operations and pit wall stability are of great importance, and this has been accomplished very effectively by the appropriate use of seepage barriers and drainage systems. At KMA, the most important items used in the system of groundwater control are standard pumping wells, raise wells that drain into a 20 km to 30 km long underground drift located just outside the perimeter of the pit, horizontal wells driven through the pit walls, and horizontal drains. This paper describes the mining and engineering technology that have been developed at KMA to control the groundwater systems and protect the mines from flooding."

Jan 1, 1992

Bahuerachi Project Characteristics Why it?s nicer at Bahuerachi Mexico is a mining country Low political, regulatory and trade risk Low social/permitting risk Proximity to infrastructure Road Power grid (8 km) Rail line (25 km) High grade zones (skarns), CRD and near surface oxide component are sweet spots to the overall system. Size of low grade system points to potential long mine life?and numerous new targets developing. Timelines-2006? 90 to 100 combined RC and core holes to go! MAIN ZONE Drilling ? Goat ?Finish Mid April ? Main Zone, going North, depth of testing dependent, estimated for May ? North Lobe-May ? Commission independent resource estimate by May 06 for results of first pass drilling to date ?tonnesand grades ?Main Zone Milestone. ? Continue infill or expanded drilling to July (minimum) ? 1stpass RC scheduled until September OTHER Targets ? Begin drill testing North Skarn target Mid-April, minimum 5 drill holes, 1,000 meters. Ongoing expansion of target with surface work (mapping) ? Road to Colome(Skarnin north of Main Zone) as part of porphyry program ? Tule(southern) porphyry and skarn system-soils and mapping OUTSTANDING events Metallurgical report on floating and leaching tests (Sulphide/oxides).

May 1, 2006

By Errol Ladner

The application of large-diameter bore holes in underground operations at Heath Steele was first tried in February, 1975. Since that time, 90,000 feet of 6-l/2-inch holes have been drilled, primarily in open blasthole stoping, for a total of 1.4 million tons, 37% of underground production. This paper deals with a review of drilling with conventional percussion longhole drills, a practice which is still utilized at Heath Steele, and the changeover to accommodate the use of larger blastholes in underground operations. The discussion will include layouts for 2-inch-diameter blasthole stope blocks, 6-inch-diameter stope blocks, trials for I. T.H. (in-the-hole) stope rooms, and drill pat/ems, drilling and performance. The complexity involved in the development, drilling and blasting of 2-inch blastholes is overcome by the over-all simplicity of drilling and blasting in I. T.H. stopes. This has made the practice of open blasthole stoping more economical and efficient. The future indicates an increase in the company's I. T.H. program. Investigations are being undertaken regarding longer holes to decrease development costs. A VCR stope is also being developed for trial.

Jan 1, 1979

By K. B. Chaudhuri, I. D. Webb, F. E. Rachor, F. A. Sauert

"A characteristic of all methods of copper concentrate smelting is that slags with a high copper content are produced at some phase of the operation. Recirculation to the smelting unit, electric furnace reduction or flotation are at present used on an industrial scale to recover the copper from these slags. This paper describes the application of the top-blowing technique, originally developed by KHD Humboldt- Wedag AG for refining of metallic copper, for the treatment of copper-containing slags. By this method, a mixture of a reducing gas and commercial oxygen is blown onto the melt at velocities which can be supersonic from the tip of a water cooled lance. The impingement of the reaction gas mixture on the surface of the slag forms a depression in the molten phase and a deflection of the jet which brings the slag into a rotating motion. This causes high rates of heat and mass transfer. Results of pilot-plant tests for batch and continuous treatment of slags are presented, and the potential applications of top blowing for industrial-scale operation are indicated. In combination with the cyclone as a smelting unit, this process appears to be economic for smelters of very low capacity."

Jan 1, 1980

By G. R. Baiden

"An Automatic Haulage Truck (AHT) has been developed for manless tramming of run-of-mine material in an operating mine. The AHT has a 70-ton capacity and uses an electric trolley system in combination with a computer control system to operate the vehicle. The purpose of the AHT was to provide a high capacity, high productivity material transfer system where conveyor belt applications are not immediately practical.The AHT project was started in 1983 at Inco Limited, Ontario Division as a result of the need for rapid material transport to match increased extraction rates resulting from bulk mining methods. The original concept was to use a continuous loader with the truck. However, in order to minimize development problems the truck project was considered a stand-alone project.The AHT project consisted of concept development, preliminaryand detailed design, manufacture, surf ace testing and mine implementation.The AHT was manufactured and ready for testing in 1988. At this point the truck was first moved onto the test track for debugging. This proved successful and in 1989the decision was made to install the AHT at Little Stobie mine on 2000 level. Commissioning of the system was started in 1990and at present a fully functional automated haulage system is in place at Little Stobie mine producing 3000 tons/day.This paper describes the project presenting results achieved to date."

Jan 1, 1992

By Eric D. Jamieson

"How well is the Canadian coal industry able to expand in the tough competition with other fuels in Canada and with other suppliers in the international, metallurgical and thermal coal trade? Coal production as a whole decreased between 1950and 1960 and, although there has been a tripling of production since then, underground production continued to decrease until 1975. This trend has been reversed to a certain extent as a result of the modernization of mines in Cape Breton, but in 1978 over 85% of coal production came from surface mining.Against this background, the paper reviews current Canadian mining operations as described in papers presented at the 1979 CIM Annual General Meeting. Conclusions are then drawn regarding some of the longer-term mining applications in relation to the latest coal demand forecast, which indicates a potential Canadian production requirement of 160 million tonnes per year by 2000. IntroductionThe Canadian 'coal industry is experiencing a period of expansion and a new record for production is set with each passing year. This growth pattern over the last IS years has been based on two main markets-the generation of electricity in Canada and the export of coking coal to Japan. Supply to those markets has entailed either the development of mining, coal preparation and transportation systems for the delivery of large volumes of products with predetermined specifications or the establishment of minesite plants designed specifically to suit the characteristics of the coal in the adjacent deposits (Fig. I).Coal is a low-value commodity in relation to its bulk, and the economics of coal use become progressively less attractive with increasing distance from the producing mine. The transportation component in the export trade and in the movement of western coal to Ontario is a major cost factor. In the latter case, it approaches the cost of coal produced at the mine. In addition, the .international competition among coking coal producers chasing diminishing markets in a worldwide steel recession as well as the competition from U.S. coals and other fuel s for Canadian thermal coal have introduced a tight set of parameters to govern mining practices in all parts of the country. Some appreciation of the required changes in mining techniques brought about by declining traditional markets and the rigorous demands of the new bulk markets can be gained by comparing production from surface and underground mines over the past 25 years (Fig . 2)."

Jan 1, 1980

By K. Musgrave, E. Solis

"This paper tells the story of how the Dome Mine in South Porcupine increased its maintenance effectiveness and reduced its maintenance costs in two phases. In the first phase, a maintenance audit was conducted, and the results led to some changes that improved maintenance, especially in the underground equipment area. The audit methods, and the changes made will be reviewed. In the second phase, management made changes in the maintenance organization and methods, following a prolonged strike during which management operated the mine. These changes were in part the result of insights learned from their hands-on operating experience. IntroductionEarly in 1989 the Dome Mine of Placer Dome Inc. in South Porcupine, Ontario, decided to improve the effectiveness of the Plant Department. The Plant Department was centralized, except for a mill mechanical crew, and serviced all operations, a townsite of 120 houses, a curling rink, and an arena. The department also operated the powerhouse, the hoists, the mine dry and provided mechanical/ electrical engineer services.At that time the Dome Mine, located in the east end of the city of Timmins and Canada's first large gold mine originally discovered in 1909, was producing about 3500 tons of ore per day with about 742 employees. Over the 83 years of continuous operation of Dome over 50 million short tons of gold ore have been processed. The Plant Department consisted of 156 hourly and 24 staff employees. At present, the mine is producing 4000 tons of ore per day with a total of 341 employees on the payroll. The Plant Department consists of 80 hourly-rated and 18 staff employees."

Jan 1, 1993

By D. Crone, T. Watts

"The Lindsley project was a program of deep drilling to test the contact down-dip from two nickel-copper deposits, one uneconomical and the other mined out. The role of Borehole Pulse EM(PEM) was to detect the higher grade, more massive sulphide zones if they were missed by a drillhole, and to help determine geometry if the zones were intersected. Two problems appeared as the PEM survey progressed: (1) conductivity-thickness as measured by the PEM did not always relate to economic sulphides as determined by the market; (2) a pattern of unusual PEM anomalies was obtained that indicated something odd and big, but the cause was unknown. A large fold structure subsequently was indicated by a program of deepening previous holes, the third of which intersected high-grade mineralization below 1280 m. Falconbridge is in the process of shaft sinking and underground exploration.IntroductionThe Falconbridge Lindsley property is on the south rim of the Sudbury basin, 8 Ian north of downtown Sudbury. The original property was acquired by a prospector named James Stobie, who, in early August 1885, staked a showing that later became the Mount Nickel mine (Fig. I). On August 10 Stobie staked another property that would become the Little Stobie mine, and at the end of the same month he staked the main Stobie orebody.In 1888, the ground immediately west of the MOlU1t Nickel find was staked. This ground contained the Blezard deposit (Fig. 1) which was put into production in 1889 and was eventually acquired by Inco. Down-dip from the Blezard workings, on Falconbridge ground, is located the upper Lindsley No. 1 deposit which was drilled off by Falconbridge in the 1940s to 1950s. A decision to go underground on the Lindsley No.1 mineralization was made in 1969, but the project was cancelled in 1971 because of declining nickel prices. The shaft was stopped at 95 m, and the headframe and hoist were sold. Further surface exploration drilling in the 1970s discovered the deeper Lindsley No. 2 zone, but as it had grades similar to those of the No. 1 zone, it too was considered uneconomic."

Jan 1, 1992

By G. Gabra

"A process of leaching niobium oxide from pyrochlore concentrate using hydrofluoric acid is described. Variables such as acid concentration, temperature, reaction time, solid/acid ratio, agitation speed and particle size are correlated to the recovery of niobium oxide.The relatively low activation energy (1,86 Kcal/mole) and the dependence of reaction rate on agitation suggest that the process is diffusion controlled. The optimum conditions for extracting niobium oxide from the leach solution, using either methyl isobutyl ketone or tributyl phosphate have been determined.IntroductionMost of the commercial production of niobium and tantalum has been derived from the treatment of columbite - tantalite minerals.In recent years (1960) , pyrochlore mineral has been found to be an alternate source of niobium . This mineral varies widely in composition and contains in addition to the main elements of calcium , sodium and niobium, some tantalum, fluorine, rare earth elements, titanium, alkali an d alkaline earth elements.It is well known that the province of Quebec possesses several pyrochlore niobium deposits totalling approximately 151 million ton s at an average 0.45% niobium oxide(1). One of the deposits, the St-Honor carbonatite, was brought into production by Niobec Inc. in 1976. Flotation o f this material produces a concentrate of about 60% Nb205(2).In view of an expanding niobium market in recent years and the presence of large niobium deposits in the province, a research and development program was initiated at the Centre de Recherches Miner ales to evaluate known processes for the separation of niobium and tantalum from each other as well as their purification . Some work has also been undertaken at the CRM to develop an improved extraction process. T his work will be the subject of further communication s."

Jan 1, 1985

By W. D. Watson

"Early in mine development at Quintette Coal Limited major problems were encountered with the fleets of primary equipment which seriously hampered production. These major fleets (cable shovels, hydraulic shovels, hydraulic drills and electric trucks) have consequently been the focal point of maintenance efforts. Some were prototypes in the Canadian mining scene and brought with them new concerns to test their skills. The problems were studied and the category and areas which were having the greatest impact on the reliability of the equipment were determined. Once defined, priorities were established and a program was initiated which was designed to accomplish a resolution. Resulting from implementation of this systematic approach, over the past three and one-half years, the fleets are now giving good reliability and industry standard availabilities. Along with these significant achievements, cost per operating hour on some of the equipment fleets has decreased substantially and continue a downtrend through 1987. This paper identifies the problems and describes the resolutions. IntroductionIn the early years of the mine development, Quintette Coal Limited (QCL) experienced production shortfalls due to problems with the major excavator and haulage fleets. A large fleet of hydraulic excavators had been purchased, and QCL was among the first northern users of all hydraulic blasthole drills. They were also using some prototype equipment and encountered problems which were not common on other types of equipment or were unknown.Because of these unique problems and lack of experience from other mines to draw on, an analytical approach was taken to areas and associated causes of the delays affecting the availability and reliability of equipment. This was done by dividing the equipment downtime into seven classifications of delays, i.e. maintenance, electrical, hydraulic, mechanical, damage, service and preventative maintenance, and tires; and then each was expressed as a percentage of total downtime. Subsequently each of the delay classification was divided into categories e.g. electrical to six categories - wheel motors, main alternator, relays, cards, no propel, lighting and 24 V system. Then, the basis for further study had been established.From this preliminary analysis of historic records, it was possible to determine the areas which were causing the majority of the downtime. These areas were then analyzed to evaluate causes and to determine possible solutions to the problem s. This paper addresses the major fleets, their problems and eventual solutions. Plea se bear in mind that the over-all objectives were to increase physical availability and reliability."

Jan 1, 1988

By G. A. Kosick, M. Freberg, L. A. Kuehn

"Highly variable and higher than forecast lead miff feed grades were problems experienced at the Polaris Concentrator. Limited flotation capacity and poor operating flexibility prevented the plant operators from overcoming these difficulties, and resulted in grades and recoveries which were lower than necessary.Two column cells were integrated into the lead circuit in an effort to give the operators the tools they required to achieve the best grades and recoveries possible, regardless of the miff feed grade. Installation of the column cells increased lead concentrate grade from 76% to 79.3% Pb, and increased lead recovery from 9/% to 91.3% Pb.This paper reviews the design, development and operation of column flotation cells in the lead circuit at the Polaris Mine.IntroductionThe Polaris Concentrator was constructed in 1980 on a barge in Trois Rivieres, Quebec, and towed to its pre sent location on Little Cornwallis Island, Northwest Territories, about 1450 km from the North Pole. The plant presently treat s about 2800 mtpd of new feed with average feed grades of 3010 Pb, 13% Zn and 5% Fe. Current production averages 36 000 tonnes of lead concentrate and 220 000 tonnes of zinc concentrate annually.The barge design and min e location dictated that the concentrator .be compact with very little unused floor space. As a result, flexibility was limited in terms of expanding the plant.Mill feed grades were highly variable and above forecast and the lead flotation circuit was found to be under capacity. This caused continued overloads in the lead cleaning circuit, resulting in low concentrate grades and recoveries. It was evident that an increase in lead flotation capacity and flexibility was necessary. The existing floor space did not allow for the installation of additional conventional flotation cells, but one alternative was the installation of column cells."

Jan 1, 1988