Search Documents

By Joe Holmes, Peter Langlois

"Falconbridge’s Raglan Concentrator, located at the northern limit of Quebec’s Nunavik Region, has been in operation since December 1997. Originally designed to process 800,000 tonnes per year of high grade nickel ore, plant capacity is currently approaching 1,000,000 tonnes per year. Optimization of the ABC grinding circuit has proven to be the most challenging component of this capacity increase. Concurrent flotation circuit modifications have allowed concentrate grades to increase from 16 to 18 percent nickel, while maintaining recoveries. Concentrate drying problems encountered during the first 15 months of operation have been addressed through equipment upgrades. The challenges associated with surface deposition of filtered tailings in an arctic environment are now better understood, and detailed design of the progressive reclamation cover is underway.GRINDINGCircuit OverviewOre from open pit and underground mining operations is introduced to the underground ore handling system via surface and underground truck dumps. Two underground bins with a combined capacity of 4000 tonnes provide roughly a day of live capacity for ore storage. Ore from the two bins is conveyed to a 150 tonne surge bin immediately ahead of the grinding circuit in the concentrator.The Raglan grinding circuit has a conventional ABC configuration (Figure 1) with a design capacity of 100 mtph (800,000 tonnes per year). The 24’ AG mill is powered by a 3000 hp motor with variable speed drive. AG discharge is sized on a 8’x16’ single deck vibrating screen, with screen oversize recirculating to a 5 %’ short head cone crusher (400 hp) before returning to the AG mill. Screen undersize is combined with ball mill discharge to feed up to 5 15” Krebs hydrocyclones. The ball mill is a 14’x 21’ overflow mill driven by a 3000 hp motor at 73% critical speed. Target Pgo for the grinding circuit product is 65 microns"

Jan 1, 2001

By G. R. Dunning, M. R. Wilson

"Abstract - The early Paleozoic accretionary tectonic regime that was established along the Laurentian margin of the Newfoundland Appalachians provided a favorable setting for shear-hosted gold mineralization along a major terrane suture, the Baie Verte-Brompton Line. The Stog’er Tight prospect is one of several mesothermal-style gold occurrences hosted by shear zones within accreted ophiolites and oceanic arc terranes on the Baie Verte Peninsula. It is an epigenetic, stratabound deposit that is confined to shallow-level gabbro sills within the volcanic cover sequence of the allochthonous Point Rousse ophiolite complex. Gold mineralization at Stog’er Tight is associated with hydrothermal mineral assemblages represented by chlorite-calcite, sericite-ankerite, red albitepyrite (±Au) and chlorite-magnetite alteration zones. Gold occurs with pyrite within the intensely altered gabbro, along the margins of syn- to late-shear, quartz-rich, replacement veins.The Stog’er Tight gabbro served as a rigid body conducive to shear deformation and fluid penetration, whereas, its high Fe-Ti oxide content induced fluid oxidation and gold-pyrite precipitation. Hydrothermal alteration involved progressive CO2, S, Na, and LILE metasomatism, along with significant enrichments in the REE, HFSE, and Th in the high-grade ore zone. Temperatures of vein formation and alteration are constrained by oxygen isotope thermometry to be between 250°C and 480°C. Isotopic compositions of vein quartz from the Stog’er Tight prospect are uniform (??O = +12.5 ± 1‰) and fall within the range cited for many shear-hosted, auriferous quartz veins.A U-Pb zircon igneous age of 483 +3/-2 Ma for the Stog’er Tight gabbro is consistent with its stratigraphic correlation with other Ordovician ophiolitic and volcanic arc/back-arc assemblages in Newfoundland. The U-Pb age of a rare variety of hydrothermal zircon recovered from the high-grade ore zone directly constrains the timing of gold mineralization to 420 ±5 Ma, in accord with a major orogenic episode of Silurian age that produced many of the magmatic and metamorphic rock suites in north-central Newfoundland. Our results are consistent with a post-peak metamorphic, late-magmatic model for gold mineralization that occurred during the waning stages of Silurian orogenesis, driven by emplacement of I-type granitoid intrusions into the crust."

Jan 1, 2000

By R. B. Rao, B. Das, J. K. Mohanty, D. S. Rao

Physical, mineralogical and geochemical characterization, along with some beneficiation approach to pre-concentrate the Ni content of the chromite overburden material of the Sukinda Valley, India, have been carried out in detail. Mineralogically, the overburden consists of geothite, quartz, hematite, magnetite and secondary silicates in varying proportions. A specific Ni mineral phase is absent in this material with the Ni and Fe being mostly enriched in finer fractions. Distribution of Ni and Fe in various size fractions and increase of Ni with increase in Fe (goethite content) indicate that goethite is the major Ni-bearing mineral phase. Quantitative estimation of goethite from chemical analysis and weight loss data indicates that the goethite quantity varies from 40% to 90%. Electron microprobe analysis (EPMA) indicates that Nirich and Ni-poor goethite are present in the overburden material. A sequential dissolution study indicates that more than 50% of the Ni are present within the goethite lattice as a lattice substitution. The results of pre-concentration studies (size classification, gravity, flotation and magnetic separation) indicate that Ni is richer in finer fractions. Further, the enrichment of Ni content is limited to 1.1% with 50% recovery by classification followed by hydrocyclone separation of the below 53 m m fraction.

Jan 1, 2000

By Joanna LaForte

"In response to “Arctic Mineral Wealth —Equitable Participation with Aboriginal Landowners – A slow or fast process?”, this author’s impression is one that, to her, seems obvious — this is definitely going to be a slow process. To question this issue seems ridiculous, unless the mining industry is considering following the same patters of the past, thereby adding to the suppression and injustices to which the aboriginals are so accustomed. To make genuine progress, where trust and good communication has been achieved with time as a factor in proceeding, the author feels, without a doubt, that the triangle of industry, government and aboriginals will seriously have to be restructured or eliminated. Anytime you mix government with progress, along with other problems, you are looking at bureaucracy, and that takes time. Issues such as the settlement of land claims have not been resolved, and in all likelihood could take forty years to finalize. Aboriginals have been suppressed for centuries by governments and industries with ethnocentric ideologies, and now that they are in a position to reclaim their lands, attain their own economies and government, and truly secure a wealthy, self-sufficient legacy for their descendants, how can anyone imagine they’ll move quickly? This author also strongly disagrees to some sections of Mr. Wakefeld’s article and will expand on her objections.We question whether aboriginals under-stand the process of mine development. If we encounter an electrical problem in our home, o we not call an electrician without having to learn the trade ourselves? This comparison seems simplistic, but does convey a point. As cited, “there are now over 100 000 aboriginals who have completed post-secondary education.” Are the numbers revealed in Mr. Wakefeld’s paper there to scare us? Is he suggesting that without the industry’s haste, the aboriginal’s new found intelligence could pose a problem to the mineral explorer. While it is true that not all are highly educated, the aboriginals have specialists in market fluctuations, feasibility studies and the needed skills. They have specialists, such as their representative organization of COPE 1984, (the Committee for Original People’s Entitlement), who under-stand their cultures, language and desires. Their education should expedite the negotiations and end the power struggles equitably. Aboriginal people are not stupid. Once they have reason to be proud, regain their communities and know the direction that they’re headed, their self-determination will return."

Jan 1, 1996

By T. Liu, C. Shi, T. Fu, M. Zhong

Water inrush in coal mines is induced by the imbalance of the groundwater flow field and the engineering geo-mechanics field. Therefore, to prevent water inrush it is important to predict the critical hydraulic pressure of water inrush in coal seam floors. This paper will investigate a method for conducting theoretical forecasting of the critical hydraulic pressure of water inrush in coal seam floors by adopting the combination method of a genetic algorithm-neural network. First, the topology structure of a neural network (NN) based on genetic algorithms (GA) will be determined and then the critical pressure of water inrush in a coal seam floor using the chosen NN will be predicted. Finally, theoretical forecasting results will be compared with actual measurement results to determine the feasibility and applicability of this method.

Jan 1, 2008

By J. E. Nesset, S. R. Rao, J. A. Finch

"For base metal sulphides, iron rejection starts in mineral processing. This review focuses on changes in plant practice specifically to improve iron sulphide rejection by control of contaminant ion effects and discusses selected general innovations in mineral processing that can be expected to play a role. One group of changes to control contaminant ions is in size reduction (the use of stage grinding and inert stirred milling) and another is in system chemistry (order of reagent addition and exploitation of the flexibility of sulphoxy reagents). Plant examples illustrate the successes, indicating that there are several options available. The general innovations start by considering the new tools for measuring gas dispersion properties and quantifying froth characteristics by imaging. Examples of their application to improve concentrate quality illustrate the potential. Other innovations stress adapting geostatistics to model variation in milling and flotation response to provide feed forward control and rigorous application of statistical experimental methodology in plant test work. An example from one concentrator shows improvements in concentrate quality from application of basic principles can be impressive.INTRODUCTIONThe more iron control (rejection) that can be accomplished in mineral processing the lower the subsequent metal extraction costs and environmental implications of iron disposal, particularly in hydrometallurgical processes. Iron rejection has been a contributing target to periodic attempts to apply mineral processing to nickel laterites and bauxites but the prime application is control of pyrite and pyrrhotite (iron sulphides) in the treatment of sulphide ores by flotation. In this paper some new concepts and innovations introduced in sulphide flotation plants over the past ten years or so (i.e., since a previous review [1]) will be outlined with examples of how they have contributed to improved “iron control”.To increase rejection of iron minerals, first the recovery mechanism should be understood. There are four principal ones, two physical in origin: 1, via locked particles (i.e., flotation of composite particles due to insufficient size reduction to liberate the minerals) and 2, through entrainment in the water reporting to the float product (an unselective process); and two originating from a response to the system chemistry: 1, true flotation (i.e., iron sulphides becoming hydrophobic) and 2, as a result of iron sulphides forming aggregates with hydrophobic particles (e.g., ”slime” coatings). There has been considerable effort to diagnose which of these dominates iron sulphide recovery; in many cases it is due to “chemistry”, in particular true flotation. The flotation effect often appears related to contamination by metal ions [1]. This can reduce selectivity in two ways: 1, metal ion species may activate iron sulphides, or 2, cause general depression which demands more vigorous flotation conditions (e.g., additional collector) with consequent loss of selectivity. This is where the review will start, by considering ways to control contaminant ions."

Jan 1, 2007

By L. Newman, R. Wyrick, R. Berezowsky

The Stillwater Mining Company operates an integrated mines, mill, smelter and base metals refinery complex in Montana, USA for the production of a high-grade platinum group metals (PGM) bearing concentrate, nickel sulphate crystal and cathode copper from the PGM-containing nickel-copper converter matte. The complex was constructed in stages over several years, starting with the mine and the mill, followed by the smelter and finally, a base metals refinery, which was commissioned in 1996. Due to the relatively small quantity of matte production, a straightforward refinery process was initially selected to extract the base metals, which reported to a mixed nickel-copper solution for further treatment off-site, and yielded a high-grade PGM concentrate suitable for treatment in a PGM refinery elsewhere. Subsequently, as a result of increased matte production, the process was modified to separate the nickel and copper, and to produce a nickel sulphate salt and cathode copper. This paper describes the design and operation of the original and the modified processes utilized in the base metals refinery (BMR).

Jan 1, 2004

By W. D. Sinclair

"Between 1934 and 1956, nearly 31 million grams of gold were produced in the Matachewan area from deposits on properties belonging to Young-Davidson Mines Limited and Matachewan Consolidated Mines Limited. In 1979, production from these properties was renewed by Pamour Porcupine Mines Limited.Most of the gold produced has come from relatively lowgrade deposits (3.4 gl t or less) that occur in an east-trending belt of dykes and irregular bodies of trachytic syenite. Although small by comparison, these deposits have some of the characteristics of porphyry copper-molybdenum deposits. The mineralized syenite contains up to 5 per cent disseminated pyrite and is highly fractured and cut by quartz and quartzcarbonate veinlets. Gold occurs as native gold along fractures, in quartz veinlets and as minute inclusions in pyrite. Minor chalcopyrite and trace amounts of scheelite, molybdenite and galena are also present. Mineralization was accompanied by potassic alteration, consisting mainly of potassium feldspar.Some gold was also produced from small, but higher-grade, deposits in volcanic rocks. These deposits occur near the syenite-hosted deposits and consist of quartz veins and stringers mineralized .with pyrite and gold. Minor gold is present in some low-grade, porphyry-type copper-molybdenum occurrences and, locally, in large, isolated quartz veins.Lead isotope analyses suggest that the gold deposits were formed at about 2700 Ma and were locally remobilized at approximately 2400 Ma, following the Kenoran orogeny. The deposits appear to be genetically related to felsic magmas emplaced in an epizonal environment and deposited from hydrothermal solutions relatively concentrated in S and K20."

Jan 1, 1982

By Marc Legault

The Duparquet mining camp situated along the Quebec segment of the Porcupine-Destor Fault was the site of gold exploitation from 1933 to 1956 and 1988 to 1991. Numerous gold showings and deposits straddle the fault. An ongoing regional metallogenic study by the Quebec Geological Survey has identified five main types of gold mineralization, each showing a distinct style, alteration, control, metal content, and timing. In order to maximise the impact of this study, a 3D regional common-earth-model was constructed along a critical segment of the Porcupine-Destor Fault with the gOcad® technology. The realisation of this model required the maximum use of the public SIGEOM numerical database, as well as the recovery of significant private data from exploration company partners. The 3D model is also a powerful new dynamic exploration tool, which can be queried using geological criteria characteristic of the different gold deposit types. This 3D model can be modified and improved continuously by adding data from new drilling, mapping or geophysical surveys. The case of the Porcupine-Destor Fault illustrates the importance of 3D common-earth-modelling in delivering refined technological geological syntheses likely to attract significant investments from the mining exploration industry, especially for deep exploration programs within mature mining camps.

May 1, 2004

By A. Ignatieff

This is the second review of developments in coal mining engineering (see C.I.M .M. Transactions, Vol. LI, 1948, pp. 262- 264) and covers the period from October, 1948, to January, 1950. Mechanization The period under review was characterized by the intensive development of appliances providing for complete mechanization of coal-face operations. A variety of machines are being evolved or have already been placed on the market which embody the principle of 'continuous mining'. This trend can be observed in all coal producing countries. In the United States, two continuous mining machines have been developed for entry and room application and by the end of 1 949 were being used in a number of mines. These are the Joy Continuous Miner in which the coal is ripped from the face by means of multiple cutter chains, and the Jeffrey Colmol employing cutters on rotating arms for chipping the coal from the face. The Joy machine is made in tw6l models, 34-in. and 48-in. high and designed for a range of seam thicknesses from 3-ft. -t-in. to 4-ft. 6-in. and from 4-ft. 6-in. to 8ft., respectively. Some experience has been gained with this machine and accounts of its performance are already appearing in the technical literature. The Jeffrey-Colmol has a more limited range of working height. The first model, 38-in. high, was designed for seams about 4 feet in thick11ess but more recently the 28-in. low model has been placed on the market for seams 2-ft. 6-in, to 3-ft. 4-in. in thickness. Conventional mobile loading machines of the gathering-arm type are continuing to yield high production under suitable conditions, and improvements or modifications of the basic principle are embodied in new machines as, for example, the Jeffrey mobile (conveyor) loader with extensible (gathering-arm) head developed for conveyor mining.

Jan 1, 1950

By Les Johnston

_ BACKGROUND - About EPCOR - Genesee Generating Station - Phase 3 Expansion _ TECHNOLOGY SELECTION - Selection Criteria - Combustion Options - Flue Gas Emission Control Options _ STAKEHOLDER VIEWS _ PROJECT STATUS _ EPCOR is an integrated utility company for water, gas, electricity and technology services. _ EPCOR has about 1.6 million customers in Alberta, Ontario, Manitoba, BC, and the U.S. Pacific Northwest. _ EPCOR Generation Inc. operates three power stations in Alberta which were in operation before deregulation, including the coal-fired Genesee Generating Station. _ EPCOR Power Development Corporation owns generating stations in Alberta, BC and Washington State and will be building the Genesee Phase 3 expansion.

May 1, 2002

By J. A. Finch

"Much progress has been made over the last several years in the ability to measure flotation cell hydrodynamic parameters in both the laboratory and plant. These techniques have allowed fundamental research to proceed to determine the effects that frother chemistry has on the main hydrodynamic parameters (gas hold up, bubble size) as well as on the amount of froth generation and water content of froth. A research program was begun that brought together a team consisting of private companies and a University with expertise in hydrodynamic characterization (McGill), flotation reagent applications (Flottec) and chemical synthesis (Sasol N.A.) with the purpose of characterizing frother chemistries with two goals in mind: Determine which frother chemistry can provide optimized cell hydrodynamics; and, create new frother chemistries with specific hydrodynamic properties.This paper describes the key steps that were taken that led to the development of new frother chemistry for use in flotation.The first step was the characterization of the major frother chemical families in a two phase system. The parameters measured were gas hold up, bubble size, froth height and water carrying rate at different concentrations and gas velocities.Analysis of the data indicated that definite patterns existed between frother chemistry and hydrodynamics and showed that frothers could be grouped into classes. More importantly, by modifying known frothers through chemical reaction it was shown that these frothers could be moved from one class to another. As a result of this better understanding of the interdependence of hydrodynamic and chemical properties, a new frother chemistry was proposed that was predicted to perform similarly to MIBC.The new frother was synthesized and hydrodynamic testing confirmed that the chemical performed similar to MIBC. Laboratory flotation tests were conducted on two different ore types that also confirmed the similar performance of the new chemical and MIBC. Subsequently, the new product was placed on a plant for a short period of time. The results showed that the product was an excellent frother but increased the flotation rate slightly more than MIBC at the same addition rate.Further research showed that the new frother chemistry was a family of products. By changing the reaction the resultant products could be made to be slightly weaker or stronger than MIBC but that this chemistry cannot provide hydrodynamic/froth characteristics similar to strong frothers like glycols and glycol ethers. Further work is planned to conduct longer plant trials to confirm the efficacy of this new frother family."

Jan 1, 2007

By D. W. Davis, P. Landais, L. J. Robb

Abstract -Nodules of carbonaceous matter have been observed in several Archaean peraluminous granites adjoining the gold- and uranium-bearing Witwatersrand Basin. These nodules, which resemble solid bitumen, usually replace uraninite or uranothorite and are paragenetically late. They show many similarities to kerogen seams and nodules associated with the conglomerate horizons in the Witwatersrand Basin, including composition, maturation, intimate association with uraninite, and a late paragenesis. U-Pb isotope ratios for granite-hosted and Witwatersrand kerogens define a single, albeit somewhat diffuse, Pb-loss discordia suggesting an upper intercept age of circa 2300 Ma. Carbon isotope analysis indicates lighter ?13C values for the granite-hosted nodules than for the sediment-hosted kerogen seams. Raman spectroscopy indicates that granite-hosted kerogen is more highly ordered than Witwatersrand seam kerogen. A model is presented which links the granitoid­ and sediment-hosted organic matter to an event of oil generation in the Witwatersrand Basin circa 2300 Ma ago. Light hydrocarbons migrated through the sediments and into underlying/adjacent granitic rocks, undergoing polymerization and accumulation in response to radiation accompanying the presence of high-uranium phases.

Jan 1, 1994

By Iann Bouchard

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

Feb 1, 2008

By Jonathan Peck, Carl Hendricks

"Global Positioning Satellite (GPS) based positioning and navigation systems have been recently developed and implemented by AQUILA Mining Systems Ltd. on blast hole drills and electric cable shovels in Canadian open pit coal and iron ore mines. These systems enable the location of the drill bit or the shovel tracks to be accurately determined in three dimensions. The position of the drill or shovel is displayed to the operator via a real-time, Moving Map Display (MMD) on an LCD-VGA screen. The MMD allows the operator to accurately navigate the drill from blast hole to blast hole or maintain a desired shovel grade or face position, with respect to displayed bench features. The maps for the MMD are downloaded from the mine office via laptop or radio link as required or as mining plans change.To obtain reliable, accurate and real-time3D positions of mobile mining equipment, proven GPS technology has to be utilized. The GPS components need to operate reliably under the severe environmental conditions that exist on board mobile mining equipment. In addition, they have to contend with varying pit geometry’s and satellite configurations, with little or no performance degradation. These issues were initially examined in December1993 during a feasibility project between AQUILA and Gregg River Resources Ltd., in relation to implementing GPS systems on blast-hole drills.To achieve certain design objectives, AQUILA Mining Systems Ltd. has developed navigation systems for cable shovels and blast-hole drills based around off-the-shelf, high precision GPS components. These systems utilize the AQUILA Advanced Monitoring Platform (AMP), to display graphically, via the MMD, shovel grade and drill position to the operator to within ±12 inches of design coordinates. Production prototypes have been installed on a Marion 301 cable shovel and a Bucyrus-Erie49-R Series III drill at the Fording River Mine in August, 1995, at the Wabush Mine on a Bucyrus Erie 190-B shovel in June, 1995, and on a GD120 drill at Gregg River Resources Ltd. in January, 1996. All these systems have undergone field trials to test system components and functionality’s under actual production conditions. This paper will discuss these GPS-based positioning and navigation systems in subsequent sections."

Jan 1, 1997

By Rocky (Yaokun) Wu

This paper introduces the development and application of a new cable anchor - Cable-Lok for pre-stressed cable bolting in mines. Cable-Lok is a spring-loaded cable anchor suitable for the drill hole diameter of 50 and 65 mm (2" and 2.5") in medium soft rock to hard rocks. The cable anchor is automatically set on installation and the cable can be tensioned immediately to provide active and primary support throughout its length. Post-grouting can be conducted independently. In comparison with the conventional cable bolting, Cable-Lok anchor will greatly speed-up the cable bolting circle and decreases the cost of cable bolting. Cable bolting anchored with Cable-Lok anchor has wide application in mines, e.g. pre-stressed cable bolting in large span drifts and intersections for permanent rock support, or in hanging walls or stopes for temporary support, or cable lace anchoring etc. This paper introduces the principle of pre-stressed cable bolting and the specifications of the Cable-Lok anchor, presented the testing results in laboratory and the application cases in mines.

Oct 1, 2010

By Justin S. Johnsen

As OEM sensors and interfaces have grown in number, the available data from equipment in the mining environment has continued to multiply. This equates to an increased visibility of operating performance, mechanical and electrical health, and predictive monitoring that can directly improve maintenance reliability and scheduling. With increased visibility, where should a reliability engineer begin to look to directly impact Capacity Assurance? More specifically, what source will provide inputs to the Failure Modes Effects Analysis (FMEA)? Results from these analyses must be documented, and they must contribute to the overall mission of the mining company; these results must reduce costs and increase profits. Through detailed data capturing, documenting, and analysis, Modular Mining Systems? Time Tracking application, used in the MineCare® maintenance management solution, can drive decisions and provide direct impact to engineering projects for continuous improvement in the mine maintenance organization.

Nov 1, 2011

By John Ramsay, Frederick A. Edwards, J. Eric Belford, Clarence V. Amyotte

"DEVELOPMENT of the underground mine is carried out from a main ramp driven from surface to the 800 and 1200 levels and from a shaft sunk to 3050 ft. Sub-levels at approximately 100-ft vertical intervals, starting 300 ft above the 800 level, were collared from the ramp as it advanced and a considerable amount of development work was pursued. The lateral and ramp work provided an opportunity to train drift crews, test equipment and methods, assess ground conditions and advance the initial stope development. The development of an exhaust ventilation raise system closely followed the extension of the level development to the south end of the orebody (Fig. 26) . On completion of the shaft, temporary lip pockets were installed at the shaft stations on the 800, 12.00, 1600, 2000 and 2400 levels. The permanent loading pocket had been installed on the 2860 level as part of the shaft-sinking contract and the level had been connected to the 2800-level station by a small muck transfer raise. Development of the 2800-level area was given top priority at this stage. This included a 1000-ft cross-cut to the crusher location, the crusher excavation, storage bins, conveyor ways and a ramp to connect the 2800 level to the loading pocket, the rope changing station and the shaft sump. The development and installation of the rock handling system between the 2400 level and the shaft bottom was contracted to Macisaac Mining and Tunnelling Company, of Sudbury, Ontario."

Jan 1, 1974

By John Frostiak

"Kahama Mining Corporation Limited, a wholly owned subsidiary of Barrick Gold Corporation, poured the first dore bar and filtered the first concentrate produced at the Bulyanhulu mine on February 28, 2001. This event marked the completion of the initial development of the Bulyanhulu Mine – Barrick’s first mine located outside of the Americas.Bulyanhulu is a 2,500 tpd underground mine located in the Lake Victoria gold belt of northern Tanzania. Gold is recovered as a gravity concentrate and smelted on site to produce dore bars or collected in copper concentrate that is shipped to offshore smelters. The facilities were constructed to meet Canadian standards. Unit operations include single stage crushing, SAG milling, gravity recovery, flotation, thickening and dewatering. Tailings are converted to paste and returned underground as paste backfill or pumped to the surface tailing site. The surface paste tailing disposal system is believed to be first of its kind in the gold industry. Paste disposal has several advantages over slurry, including lower dam construction costs, reduced water losses, and lower reclamation costs. This paper describes the facilities and discusses the challenges faced during development and construction including logistics, lack of infrastructure, recruiting and training, security, and social issues as well as initial operating results.INTRODUCTIONBarrick Gold Corporation completed the Bulyanhulu mine development in 2001. Capital cost of the project was US$280 million. The mine produced 241,575 ounces from start of milling to year end at a total cash cost of $197 per ounce. Numerous challenges were overcome in the mine’s development due to the general lack of infrastructure in Tanzania and the mine’s location some 1200 km inland by road from the port of Dar es Salaam."

Jan 1, 2003

By Robert J. Kuhne

The Iron Ore Company of Canada has successfully employed advanced process control (APC) to optimize the operation of their induration machines. A significant increase in machine throughput and a reduction in fired pellet quality giveaway were observed following the APC implementation on all six machines. This paper discusses the opportunity for process control optimization in induration, reviews the property estimation and multivariable control technologies, and describes how the IOCC control strategy captured this opportunity. APC performance data is presented. The dependence of APC performance on control room operator acceptance, process equipment and instrumentation is highlighted.

May 1, 2007