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By S. Koski, J. Vanderbeek, J. Enriquez

"The Cerro Verde copper-molybdenum porphyry mine, majority owned and operated by Freeport- McMoRan Copper & Gold, is located 30 km southwest of Arequipa Peru. The concentrator, which produces copper and molybdenum concentrates, started operating in late 2006 with a 108,000 tpd design capacity, processing primary sulfide ore (mainly chalcopyrite and molybdenite). Plant capacity was recently increased to 120,000 tpd. The comminution circuit consists of one 60” x 113"" primary crusher, four MP-1000 secondary crushers in closed circuit with dry screens, four 2.4m x 1.6m High Pressure Grinding Rolls (HPGRs) in closed circuit with wet screens, and four 7.3m x 11m gearless ball mills in closed circuit with cyclones. The HPGR circuit is fed by the Secondary Crushing circuit product at a T80 of 35 millimeters, and the HPGR circuit product feeds the Ball Mill circuit at a T80 of 3000 microns.This paper describes operating experiences with HPGRs during these first four years highlighting improvements in operating practices and presentation of data regarding operational efficiencies, also discussed are the primary benefits provided by HPGRs such as production of micro fractured particles, reduced ore Bond Work Index, and reduced power consumption. Cerro Verde represents the first installation of HPGRs in both the copper industry and large scale hard rock mining."

Jan 1, 2012

By Fidelis T. Suorineni

HydraboltTM is a Swellex-type dowel support element developed and manufactured by New Concept Mining in South Africa. Like Swellex, the HydraboltTM is a folded tube which can be inserted into a larger diameter hole without pushing. It is then activated by injection of high pressure water which inflates the folded tube to intimate contact with the walls of the borehole at a set pressure, normally 25 MPa. Unlike Swellex however, the set water pressure at the end of the inflation is maintained throughout the life of the dowel. An integral non-return valve makes this possible. The HydraboltTM is being investigated as a possible stress change measuring cell. This paper presents the results of closed form solutions, numerical modeling and laboratory test to date. Preliminary results indicate that the HydraboltTM can be used as a stress change monitoring cell in addition to its conventional role as a rock mass reinforcing element. If successful, the HydraboltTM will supplement microseismic monitoring systems in rockburst-prone ground conditions where they will give quantitative stress change data for both mine design model calibrations and means for proactive safety measures.

Oct 1, 2010

By Bryon Cerklefskie, Michael Schulte

"This case study explores the usage of polymer ducting as a replacement to curtains and FRP for face ventilation in two coal mines. There are two mines looked at, one is the highest elevation underground coal mine in North America, the other is the gassiest mine in North America. The paper details the trials of both mines switching from FRP and curtain respectively to polymer ducting. The results discuss the ability for the mines to not only achieve consistent airflows and keep them in compliance but the unexpected positives. Mine A was allowed to do longer cross cuts due to increased air volume at the face. This drastically cut their costs of mining down due solely to modification of the ventilation cycle. Mine B saw economic benefits due to longer cuts between place changes. Both mines have documented lower dust, methane, noise, and improved wear and tear on their equipment as a result.INTRODUCTIONThe emergence of longwall mining in underground coal operations has resulted in new ventilation challenges. Numerous production crews strive to complete their development sections with enough time to adequately prepare for the upcoming longwall panel. Continuous miners will cut out two or three entry development sections per their ventilation plan, that is approved and controlled by MSHA (Mine Safety and Health Administration), which will drive amount of footage that can be mined at a time prior to installing roof support. At this moment the continuous miner, hereafter referred to as the CM, will back out of the entry and moves to the second entry to complete a similar cut. Typically, a roof bolter crew will pull in to the finished cut section and install ground support. This is called a place change style of production coal mining. There is an alternate method that includes a miner/bolter combination as well but that was not featured at either test site in this case study. Ventilation has to be provided to sweep the working face of each entry to control dust and gasses. Each task will have an MSHA prescribed ventilation requirement dependent on the dust levels and methane emissions of the rock for that particular mine. The CM, roof bolting and unused headings will each require constant ventilation but at different volumes. Since each working face is changing throughout the mining cycle the ventilation requirement in a working heading is never static and is changing with the working task.Traditional Ventilation ControlsTraditionally face ventilation for coal mining operations has been completed thru the usage of a curtain system and\or using auxiliary fans and ventilation tubing. Room and pillar mining systems typically utilize curtain systems, which use curtain walls that are installed by the miners by erecting wood framing and covering it with brattice curtain. This splits the drift width to allow fresh air to sweep the face and take the contaminated air and dust behind the curtain to the ventilation exhaust\return area of the mine. This method is difficult to adjust the airflow from entry to entry during changing cycles and requires that a wider drift is mined out in order to have enough room for the brattice wall. In operations that require roof bolting, this method limits the length of the cuts from the CM prior to advancing and can lead to not providing enough ventilation to keep dust and methane levels below compliance requirements."

Jan 1, 2019

By C. J. Hodgson

"IntroductionThe Kitsault molybdenum mine is located 600 m above sea level on Lime Creek at the head of the inlet of Alice Arm, 140 km northeast of Prince Rupert, British Columbia (Fig. 1). The area of the mine is characterized by rugged topography and deeply incised creeks which drain into the Portland Canal - Observatory Inlet fjord system. Access is by air service or boat from Prince Rupert, or by secondary road from Terrace.HistoryThe deposit was first staked in 1911, at which time the main feature of interest was a polymetallic vein with values in silver located southeast of the molybdenum deposit (Woodcock and Carter, 1976). Turnbull (1916) was the first to describe the extensive zone of crisscross quartz stringers with Mo~ on the banks of Lime Creek which, although it clearly had the potential to contain a major deposit, was not then believed to be of commercial value.Following sporadic work through the 1920s and early 1930s, the ground lay idle unti11959 when Kennco Explorations (Western) Ltd. commenced a program of systematic diamond drilling on the stockwork-type mineralization adjacent to Lime Creek. In late 1964, Kennco announced the presence of an orebody of 36 million tonnes averaging 0.230Jo Mo~ which was to be put into production at a rate of 5450 tonnes per day under a new subsidiary, British Columbia Molybdenum Ltd., at a forecasted capital cost of $20 million (revised to $30 million).Between January 1968 and April 1972, 10.4 million kg of molybdenum were produced from 9.3 million tonnes of ore, at an average mill recovery of 90%, and with an average mill head grade of 0.206% Mo~. The ore was mined in an open pit with a waste to ore stip ratio of 1.5 to 1. The. operation was terminated in 1972 due to weak molybdenum prices and escalating costs.In May 1973, the deposit was purchased by Climax Molybdenum Corporation of British Columbia, Limited and in 1979 transferred to affiliate Amax of Canada Limited. In early 1979, following completion of detailed feasibility studies, Arnax commenced construction of the 10 900 tonne per day Kitsault mine and mill complex based on a mineable open pit reserve of 95 million tonnes at an average grade of 0.192% Mo~, sufficient for a mine life of 25 years. The original capital cost estimate was $143 million; it subsequently escalated to approximately $200 million."

Jan 1, 1995

By E. L. Warburton

Before entering into a discussion of wet washing, it will be advisable to consider the various phases and conditions sur- rounding the problem of cleaning coal from the Corbin mines. Corbin is located in the south-east part of British Columbia in the Crowsnest Pass district, about 35 miles north of the International boundary and about three miles west of the Flat-head Range of the Rocky Mountains. It is reached by a rail-way, about thirteen miles long, from McGillivray, B.C., a point on the Crowsnest branch of the Canadian Pacific rail-way, owned and operated by the Eastern British Columbia Railway Company, a subsidiary company of Corbin Coals, Limited. The coal is assumed to occur here, as principally elsewhere in the Rockies, in the Kootenai series of the Lower Cretaceous, but owing to the disturbed condition of the surrounding country and, therefore, the magnitude of the geological study involved, this has never been definitely worked out. The coal is of the usual Crowsnest high-grade steam-coal, containing from 9 to 12 per cent. of ash, but appears to have 4 to 5 per cent. less volatile combustible matter than other coals being mined in this district, a representative analysis being about as follows:

Jan 1, 1924

By R. Mulligan

"The Cordilleran tin belt extends from the Seward Peninsula in westernmost Alaska to Mexico. Throughout the Canadian section, tin occurrences are mainly confined to a belt along the northeastern fringe of the Western Cordilleran sub-region; the boundary of this sub-region with the Eastern Cordilleran sub-region is most simply defined as the practical eastern limit of granitic and metamorphic rocks. The stratified rocks underlying this restricted belt are mainly late Precambrian and early Paleozoic miogeosynclinal sedimentary rocks, which are more or less metamorphosed but otherwise are generally equivalent to the less severely deformed rocks underlying the Eastern Cordilleran sub-region. They contrast with Late Paleozoic - Mesozoic eugeosynclinal volcanic-sedimentary assemblages farther west, but the granitic intrusions throughout are mainly of Late Mesozoic age. Thus, narrowly defined, the tin belt largely coincides with a lead-zinc-silver metallogenic province, whereas copper deposits characterize the eugeosynclinal regions to the west. In addition to the tin occurrences, which include the Sullivan lead-zinc-silver mine, Canada's only significant producer, the belt contains all the beryllium, most of the tungsten and many Iithophile-type molybdenum occurrences. Several types of occurrences of each metal are represented. Lithium occurrences in the Canadian Cordillera are notably rare, and these few are insignificant."

Jan 1, 1971

By A. Supomo, H. Resendiz, C. Burbidge

"Freeport-McMoRan Inc. (FMI) commissioned the expansion of the Morenci Metcalf concentrator in 2014. The concentrator included many design and equipment innovations, including the first-of-its-kind Metso Hydraulic Roll Crusher (HRC), variable speed ball mills and variable speed crushers. In addition to the innovative design, FMI commissioned the Metso APC team to design a realistic process simulator and the plant APC. The process simulator was utilized to train operators before commissioning, which led to a smoother plant start up. The plant APC utilized the concept of dynamic constraint control, which controls the feed to the primary ball mills by “pulling” the tons from crushed rock storage bins, which then automatically are filled by the upstream HRC and secondary crushing circuits. The primary ball-mill control also adjusts the water addition to the cyclone clusters to avoid overload and achieve sufficient grind size. The constraints include in-circuit constraints for feeder capacity, screen-deck capacity, ball mill power, cyclone mass flow, pump capacity and pump motor capacity. The APC system was implemented shortly after the start of commissioning and immediately demonstrated increased throughput and an ability to highlight and quantify process constraints and bottlenecks. The following paper outlines the control strategy, discusses system implementation, results and challenges.INTRODUCTION The FMI Metcalf Concentrator is located in Morenci Arizona on the site of the old original Concentrator. The new Metcalf concentrator started operation in May of 2014. This plant was designed for an average of 63,500 tpd (70,000 stpd), increasing the total Morenci concentrator complex production to a nominal 113,400 tpd (125,000 stpd). The process flow diagram is shown below in Figure 1.The process consists of primary crushing feeding a coarse ore stockpile followed by secondary crushing operating in closed circuit with vibrating screen decks. The screen undersize feeds the first of its kind Metso hydraulic roll crusher (HRC) operating in a closed circuit with vibrating screens. The primary crusher is a Metso 60x110 gyratory crusher. Secondary crushers are Metso MP1250 Crushers with variable speed drives. Secondary crusher discharge is recycled to the dry screen feed bin and screened with oversize returning to secondary crushing and undersize feeding the Metso HRC3000. The product from the 3.0 meter X 2.0 meter roll crusher is wet screened with the undersize feeding the grinding circuit, which is comprised of two each 24-foot diameter by 40- foot-long variable speed ball mills running in parallel with each in closed circuit with a cyclone bank of 12 cyclones. The wet screen oversize is recycled to the HRC feed bin."

Jan 1, 2019

By Sadan Kelebek, S. O. Fekete, Gerhard W. Heinrich, Peter F. Wells

"For many years, rejection of pyrrhotite at the milling stage has been a viable method for sulphur dioxide abatement. Pyrrhotite rejection options have included the use of selective pyrrhotite depressants in flotation; a depressant which has recently come into use is diethylenetriamine (DETA). This reagent has been the subject of recent research and development efforts in the processing of nickel-copper sulphide ores.In the present study, adsorption trends for DETA have been monitored under the dynamic conditions of flotation using a spectrophotometric method which has been adopted for this purpose at Falconbridge Limited. The results indicate that the adsorption of DETA is quite fast and in the majority of cases, accounts for the disappearance of 75-95 % of this reagent from pulp's liquid phase. The adsorption decreases linearly with an increase in the DET A dosage from 100 git to 600 git. The tailings produced in flotation tests were subjected to washing with deionized water at 60 °C to examine the desorption of DET A. These results indicate that the amount desorbed increases with increasing DETA dosage used during flotation but is less than 7 per cent of that adsorbed. It was found that adsorption of DETA alone, even at relatively high levels, does not always cause depression of pyrrhotite. A new combination of reagents identified in the metallurgical laboratories of Falconbridge Limited utilizes sulphur dioxide with DETA. These reagents together are capable of efficient depression of pyrrhotite on a consistent basis."

Jan 1, 1995

By J. W. Bingay

The expansion of the mining industry, with other industries, of course, is dependent upon a supply of fresh capital from year to year. Mining is a speculative form of investment, though there is a wide range of risk as between indiudual undertakings. All of the leading financial writers, nowadays, agree that expansion is being seriously interfered with by the unprecedented load of taxation Canadians are carrying. Individuals have less for investment and corporations are obliged to defer necessary expenditures in order that the demands of the taxing authorities may be met. Naturally, speculative investments such as mining exploration suffer first. Undoubtedly, a great deal of cash raised by taxes, if left in the hands of individuals and corporations for investment and expansion, would have been far more beneficially used and would have developed the country more than any use made of it by the government, in the way of bonusing new industries, or the undertaking of large schemes of development. Government undertakings of this nature are often entered into without a proper knowledge of cost and probable return. Expert expenditure of the same sums by business men or corporations undoubtedly would generally produce more prosperity for the country as a whole. The absolute necessity for lower taxation is being increasingly known to the public at large, and eventually it is hoped that our governments will see the economic impossibility of continuing the present rate of expenditure. The successful Finance Minister of the near future will not be the one who can borrow the most money.

Jan 1, 1924

By Allan R. Punkkinen

Safe extraction of the valued ore resource in the deep levels of VALE Creighton Mine has progressed in a pillar-less fashion using vertical retreat, slot-slash and uppers retreat methods since the cessation of ?cut and fill? mining in the late 1980?s. Sequencing of the panel extraction and filling has been the key to successful exploitation of high stress orebodies at depth. In late 2010, discussions between the Operating Department and Creighton Ground Control revealed an opportunity to evaluate a trial primarysecondary sequence in the west end of the 400 Orebody at the 2340m horizon. To manage the trial primarysecondary project, a high level risk analysis and management of change was carried out to mitigate potential danger. As part of the requirements, an instrumentation project was conducted in the hanging wall and footwall bottomsills of the secondary panel and within the secondary panel itself. The extraction sequence was modeled with Map3D® software, confirming high stress levels with the advance of the primary panel. Enhanced ground support was installed based on modelling results. A key objective of the instrumentation project was to verify support system response to mining and to obtain knowledge in regards to the behavior of the stope. This paper describes the first time that this type of new innovative instrumented rockbolt technology had been used in a hard rock mining environment. Understanding of the physical deformation mechanisms of ground support in response to high stress conditions is the basis for an effective ground control strategy. The data played an important role in subsequent enhanced ground support system design at the mine and importantly, established the fact that the secondary pillar had not totally failed. Subsequent cavity monitor results helped establish that fact.

Jun 1, 2012

By Halet. R. A.

"The Quesabe Mine, owned by Brunston Mines Limited, is a gold deposit in the south central part of Duprat Township, northwestern Quebec, about 10 miles northwest of Noranda.It is one of the few gold mines in Canada developed since World War II. The occurrence of gold in the Quesabe fault structure has been known for many years, but serious exploration did not begin until 1945. By 1949, 15,000 feet of diamond drilling had been completed and a shaft sunk to a depth of 635 feet, with lateral development on the 450 and 600 foot levels. In 1949 and 1950 a new shaft was sunk to 1,050 feet, new levels were established at 800 and 1,000 feet, and ore was mined and shipped to the Noranda smelter. After November 1950 the ore mined was treated in the company's own mill. The grade of ore was marginal under existing economic conditions, and production was suspended in April 1952. The mine produced about 100,000 tons of ore with an average grade of approximately 0.25 ounces of gold per ton.GeologyThe bedrock formations are all Precambrian, and the general geology of the area has been described by W. G. Robinson (1). The rocks in the vicinity of the mine are acidic and basic volcanics of the Keewatin series (andesite, rhyolite, agglomerates, tuffs) invaded by the Flavrian Lake granite stock, and by dykes and irregular masses of intrusive felsite, quartz porphyry, syenite-porphyry, diorite, and lamprophyre.The mine workings are in andesite and felsite, about 2,500 feet west of the western margin of the Flavrian Lake stock.The principal structural feature of the area, from an economic point of view, is the Quesabe fault. This steeply-dipping fault cuts all the rock formations of the area, and has been traced for about 11 miles along a strike of north 65 degrees east from Lake Arnoux in the northeast corner of Dasserat Township to Duprat Lake near the east boundary of Duprat Township."

Jan 1, 1949

By G. A. Sutton

This paper, describes a case example from San Manuel mine, where in situ copper leaching of the supergene zone was done over a 14 year period (1986–1999) in conjunction with underground and open-pit mining operations of a copper porphyry deposit. In 1993–1994, testing of well fields was done to determine the amount of copper that would be recovered from in situ leaching of the supergene zone, which was composed primarily of chrysocolla and copper-clay minerals. It was determined that the leach fluid would reach 70% (‘sweep efficiency’) of the copper minerals and that 75% of them would be leached for a recovery of 52% of the acid soluble copper. However, the final results from Zone 6, which had the longest leach history, showed that approximately 42% of the acid soluble copper was recovered, indicating that the `sweep efficiency’ was closer to 55%. Comparison of drill-core assay data from two holes, one drilled before (ARM158) and the other after (SMO9607) leaching, also indicate that approximately 42% of the acid soluble copper was recovered. The discrepancy between the predicted (52%) and actual (42%) recovery is probably related to a combination of factors, including difficulty in maintaining fluid saturation, channeling effects and gypsum precipitation. INTRODUCTION In situ copper leaching at the San Manuel mine, Arizona, was initiated in 1986. It was recognized that some of the copper oxide resource was not going to be economically recoverable by conventional open pit and heap leach methods using solvent extraction and electrowinning (SXEW). A high stripping ratio would be required to access part of the resource. At the time, in situ leaching was becoming popular in the uranium industry but the approach was virtually unknown in the copper industry, especially not at a large scale.

Jan 1, 2019

By J. Keith Haddock

"Introduction The Boundary Dam Mine is located 5 km south of the City of Estevan, Saskatchewan and is operated by Manitoba and Saskatchewan Coal Company Ltd., one of the Luscar companies. The entire production of 1.7 million tonnes per year is delivered to the Boundary Dam Generating Station of Saskatchewan Power Corporation. Geology There are basically two seams mined on the property, the main Estevan seam ranging in thickness from 3.0 m to 4.5 m with partings and the upper Roche Percee seam (roughly 15 m to 23 m above the Estevan) which ranges from 0.6 m to 2.0 m in thickness. Most of the reserves are concentrated in the Estevan seam, the Roche Percee only being mined whenever its thickness makes it economic to recover. The coal measures belong to the Ravenscrag Formation of Tertiary (Paleocene) Age. This formation is widespread in North Dakota and Montana and contains the lignite fields of North Dakota and subbituminous coals of Montana. The formation is gently tilted to the southeast at Boundary (0.5 degrees) and consists of weak sandstones, siltstones and silty mudstones. Reserves and Coal Quality The present minesite encompasses a coal reserve of approximately 50 million tonnes calculated to a maximum stripping depth of 37 metres or 20:1 mining ratio. The reserves form only a part of the total reserves in the Estevan area which are owned by the Saskatchewan Power Corporation. The coal being mined is classed as Lignite ""A"" and has the following specifications:"

Jan 1, 1985

By Y. Kocaefe, S. Afshar, D. Kocaefe, Z. Kunt, C. Allaire

Interaction of aluminum with silica based ceramics Jose M. Soto, Jeffrey D. Smith, William G. Fahrenholtz. Department of Ceramic Engineering University of Missouri-Rolla Rolla, MO 65409-0330 USA ABSTRACT Interactions between A356 aluminum (Al-Si alloy) and dense fused silica (FS) riser tubes used for low-pressure casting of aluminum alloys were evaluated using a sessile drop approach. The tubes have a short service life, but cost and thermal shock resistance make them an effective solution. The main problem encountered during use is the reaction of aluminum with silica to form alumina and silicon, which causes failure. Tests have been conducted on as-fired (uncoated) and modified (coated) tubes. Experiments were carried out in a horizontal furnace at 1225°C under argon to minimize the effect of the aluminum oxide on the interactions at the alloy-silica interface. Images of the drop were acquired and contact angle values were estimated for uncoated and coated samples, but no significant differences in the contact angles were observed. Scanning electron microscopy revealed the presence of cracks at the interface between the reaction zone and the unreacted silica. The presence of reaction products (silicon in the reacting alloy and aluminum in a reaction zone between the alloy and the unaffected silica) has been confirmed using energy dispersive spectroscopy. A two layer coating system was found to be effective in reducing penetration of the aluminum alloy. The interactions between bed media and aluminum have been studied under static and dynamic flow conditions. An experimental system was set up simulating a small filter. Desired flow field can be created around alumina particles and velocities can be adjusted. A mathematical model was developed to predict the velocities, and this was validated using data from a visualization study. The interaction zone on the surface of the particles was analyzed with optical microscopy and SEM. This paper presents the study and compares the results under static and dynamic flow conditions.

Jan 1, 2004

By Alvaro Diaz

Introduction, who is Teck Red Dog and Quebrada Blanca Mines Uniqueness of environment Arctic versus High Altitude Conditions Logistical challenges People and Stakeholders Conclusions

May 1, 2013

By G. W. Poling, J. R. Hoffert

"A common practice in preventing gravity-fed tailing pipeline from plugging due to sanding is to add lime at relatively high dosage rates. The lime affects the rheology of the slurry ""vehicle"" which transports the coarser particles in a heterogeneous flow-regime. This paper describes a study of the effect of lime on the critical deposition velocities and friction head losses of Highmont Mining Company's mill tailing. Testwork using an extrusion viscometer was related to the surface chemistry changes brought about by the high lime additions. Lime additions which typically increased the tailing pH from 8.4 to 11.5 reduced the critical deposition velocities from approximately 3.2 to 1.7 m/sec.IntroductionCommon practice, at least in base metal concentrators in British Columbia, is to use high lime additions in tailing slurries when the pipeline becomes partially plugged with sands. Some concentrators, such as the Highmont Mining Co. Ltd. plant, add lime on a continuous basis during low tonnage periods and during startup/shutdown transition s. Although such high lime additions often solve temporary plugging problems, the effect of lime on slurry rheology has not been well understood.Slurry pipelines are designed to transport solids in suspension with a minimum of wear and without particle deposition. These two objectives are in opposition because the velocities required to maintain solid suspension can sometimes cause high head losses in the pipeline, as well as wear problems. Thus, the optimum velocity for a long distance slurry pipeline is in the range that provides just enough turbulence to keep coarse particles in suspension."

Jan 1, 1985

By Stephen Mcgibbon, Tim Twomey

"Abstract - The High-grade Zone (HGZ) was discovered 5000 ft (1520 m) below surface in the hangingwall of the existing orebody, 46 years after the Red Lake mine first went into production. The very rich ore of the HGZ is characterized by a remarkably abundant distribution of visible native gold. The location of this discovery challenged conventional wisdom at the time and its genesis has yet to be fully understood. Textural observations of ore within carbonate veins as well as crosscutting relationships suggest peak-metamorphic emplacement for at least some of the gold. Post-lamprophyre dike remobilization of gold is locally observed in the HGZ. Structure and dilatancy were the key elements for localizing ore at the Red Lake mine. Ore occurs where a fault trend intersected folded ultramafic volcanic rock that created a semi-permeable cap-rock to ore fluids ascending the "feeder" structure. This was enhanced by strong competency contrasts between the eastern ultramafic rocks, felsic volcanic rocks west of the HGZ, and the mafic volcanic host to ore - an exceptional environment for the development of protracted dilatant fluid pathways for gold deposition.Development in the HGZ began in February 2000 and reached commercial production on January 1, 2001 at a capital cost of US $53 million. December 2001 reserves are 1.9 million short tons (1.73 Mt) at an average cut and diluted grade of 2.05 ounces per ton gold (70.5 g/t) containing 3.8 million ounces of gold. The extremely rich ore presented a unique challenge in grade estimation for the Geology Department at the mine. The historic cutting factor was replaced by a statistical method as more data were collected from mining and mill reconciliation. The mine produced 503 000 ounces of gold in 2001. Exploration at the mine is targeting HGZ-type ore formation within basalts associated with the intersections of fluid pathways and folded ultramafic rocks, as well as other targets."

Jan 1, 2001

By P. Maltby

"Smelter Feed Preparation Falconbridge Nickel Mines Limited, Sudbury Operations, operate 4 mills and a smelter to produce Bessemer Ni-Cu matte for refining in Norway. Approximately 1400 tons of Ni-Cu concentrate are produced daily which are dried from a filter cake containing 14% moisture to 7.5% moisture pellets. Concentrate drying is done by 4 rotary dryers as shown in the 'Dryer Performance Data' at four separate locations. The dryers all form part of the feed preparation stage prior to sintering.The rate at which concentrate can be produced through the Sinter Plant largely depends on the quality of the dried product which makes up the feed. A feed consisting of mostly hardened pellets will sinter much faster than a feed which consists of broken pellets and dust. Dryer products require:1. Good green strength to survive shipment and handling.2. Correct moisture content.3. Sizing within a range ideally from 1/4"" to 10 mesh in diameter.Dryer performance data is shown in Table 1. Capital costs between the two types of dryers are comparable with the Roto-Louvre producing generally a larger better-formed pellet. Dryer feeds differ in that at both Hardy and Fecunis, Ni-Cu concentrate filter cake is the only feed while at the Falconbridge slurry plant the dryer feed can consist of up to 10% by weight of smelter flue dust resulting in a combined concentrate-dust pellet for feeding to the Sinter Plant. To the Falconbridge Sinter Plant dryer, dust and limestone are added for the smelting process in addition to Ni-Cu concentrate."

Jan 1, 1972

By Eric J. Grimsey, Don C. Ibana, David E. Grimsey

The segregation process as applied to nickel laterite ores involves the formation of gaseous nickel and iron chlorides which are subsequently reduced to form ferronickel on the surface of a solid carbon reductant. A fundamental study of the process has been carried out using limonite, nontronite and garnierite ores. The study highlighted the significant impacts that ore mineralogy and carbon addition have on the amount of nickel which is segregated rather than retained within the ore due to in-situ reduction. These important aspects affecting nickel recovery and the success of the process are discussed in this paper.

Jan 1, 2017

By René Dufour

Jusqu?à son acquisition par MM René Dufour et Alain Robin en 1994, les claims miniers et les droits de surface de la propriété étaient détenus depuis 1953 par la société Québec Columbium, une filiale de la socité américaine Kennecott Copper qui y a réalisé d?importants travaux miniers. En 1995 la compagnie NIOCAN inc. fut incorporée; ses actions furent inscrites à la bourse de Montréal en 1997, et à la bourse de Toronto en décembre 1999. Jusqu?à maintenant, NIOCAN a investi plus de 7 millions de dollars dans le développement de sa propriété minière de niobium située à quelques 40 kilomètres au nord-ouest de Montréal. Le haut rendement économique des deux gisements principaux que compte exploiter la compagnie, le S-60 et le HWM-2, a été établie par des études de faisabilité effectuées par le consortium Met-Chem/SNC-Lavalin. La mission que s?est donnée NIOCAN inc. consiste à mettre en production ses deux gisements et à devenir ainsi productrice de ferroniobium dans les plus brefs délais. Figure 2 Le projet est présentement à un stade avancé d?obtention du certificat d?autorisation du ministère de l?Environnement. À plus long terme, la compagnie compte aussi exploiter les sous-produits de ses gisements (apatite, forsterite, magnétite, calcaire et terres rares).

May 1, 2003