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By Rudy Tenbergen, Dick Farmery, Jim Naylor

"Paste backfill has replaced cemented rock fill as one of the components to improve ground · control and mine safety at the Macassa Operation of Kinross Gold Corporation in Kirkland Lake, Ontario. It is the first operation to utilize "" flash thickening ""of very fine gold tailings to a paste consistency in the ""Paste Production and Storage Mechanism"", a joint technical development of Inco and GL&V. The tailings paste is mixed with alluvial sand to produce an engineered quality paste backfill. The development leading up to the decision to proceed with this novel technology is discussed, as well as commissioning of the backfill operation.IntroductionThe occurrence of a major rockburst on November 23, 1993 prompted a review of mining and backfill procedures at the Macassa No 3 shaft . This shaft is some 7238 ft deep and lies in a mining belt that is prone to seismic events. The recommendations were to change the mining from underhand cut and fill to mechanized long hole stopping and to look at alternatives to the rockfill backfill system in place. The Macassa cemented rock backfill operation, while producing the desired fill stiffness had drawbacks as compared to paste fill. With paste fill, placement rates are faster, more openings can be filled, it is less expensive and less prone to the occurrences of compensable incidents.Macassa mining personnel visited the Sudbury operations of Inco in 1993, where development on paste backfill was in progress. As some of the R&D was taking place with funding from the Premier's Council Technology Fund of the Ministry of Trade and Technology of the Province of Ontario , Inco personnel at that time did some feasibility and conceptual consulting on the use of paste fill for the industry. Inco had developed the use of alluvial sand paste fill, an engineered blend of alluvial sand and tailings fines and was doing development work to eliminate the ""conventional"" way of producing paste from mill tailing by thickening and filtration. This latter development work was taking place with GL&V Ontario. That work led to the filing of a joint Inca/ GL&V patent application for the PPSM, the Paste Production and Storage Mechanism with all marketing rights being held by GL&V."

Jan 1, 1997

By Nicolae Dobritoiu

The literature in this field and the practical activity record that a method, respectively the technology used for an underground mining work have many components which, in order to be applied, demand that for each of the parameters that describe the environment of the mining work and that influence the chosing of that method and that technology of execution, must have values in an interval well determined. There are situations when one or many parameters of the set of parameters that describe the environment of the mining work, can modify its values, and, as a result, one or more components of the methods or technology cannot be applied anymore, making necessary a replacement of their values. The information offered by this graphical-analytical model allow the determination of optimum solutions for the process of digging of the underground mining work and thus it will result the incresing of the technical-economical efficiency of the digging process and, also the increasing of the quality of the underground mining work.

Oct 1, 2009

By E. Wasmund

"Sandfire’s DeGrussa Copper-Gold operation in West Australia is a new high grade copper sulfide mine, which includes a 1.5 Mtpa concentrator which was completed in 2013.Early after commissioning, it was identified that the flotation capacity in the all-mechanical cleaner circuit was not sufficient. In order to improve recovery, the tail from the cleaner scavenger was sent back to feed the rougher scavengers. Test-work was done on-site to evaluate the possibility of using a flotation column as a pre-cleaner. A CavTube™ sparging system was selected, which is especially effective for fine ore particle flotation. Test-work was conducted at site using a 150 mm diameter unit, and then confirmed on a 500 mm diameter unit. A 4250 mm diameter full scale unit was installed in Q4 2014 and commissioned in Q1 2015. This unit gave some significant advantages including a reduction in re-grinding requirements, elimination of a circulating load and increase in the recovery of copper in the cleaner circuit and overall circuit.In this presentation, the benefits of columns and cavitation sparging for floating fine particles and rejecting fine entrained gangue will be explained. Also, the results from a lab unit and a pilot unit will be compared against the results of the full-scale unit. The paper will demonstrate the scalability of flotation columns, and which phenomena and scale-up criteria must be considered to be successful. Finally, some general observations will be made about the importance of columns in copper cleaning circuits.IntroductionSandfire Resources’ DeGrussa copper-gold concentrator is located approximately 900 km north-north-east of Perth in Western Australia. The project area landscape is scrubby mulga lands with few notable features. The climate is arid with high temperature and heavy summer downpours."

Jan 1, 2016

By M. Rantapaa

Measurable improvements in throughput have been documented at Barrick Goldstrike due to increased ore fragmentation through efficient drilling and blasting techniques. A decrease in throughput at the autoclave, due to increasingly hard ore, was identified in early 2002. A team of individuals from the open pit and process areas worked closely on the Drill-to-Mill (D2M) Continuous Improvement initiative to ensure that it would address the needs of both groups, with the target of actually improving throughput in future years, despite the projected harder ores. A series of tests were conducted to determine if adjustments to drilling and blasting could positively influence throughput. Better fragmentation and a subsequent increase in mill throughput were achieved through the use of electronic caps for more precision and flexibility, as well as for allowing extremely fast shots; explosives with a higher velocity of detonation (VOD) to provide for improved shock energy; and improved distribution of the explosives by decreasing pattern spacing. Early tests indicated a significant increase in throughput when processing identified harder ore. It is anticipated that the total process throughput (hard and soft ore) will increase by 6 tph in 2003 due to the improved fragmentation of the hard ore. Barrick Goldstrike?s D2M initiative includes roaster hard ore (BWI>17), as well as autoclave hard ore (BWI>15). Approximately 6 million tons of D2M material were shot in 2003, a relatively small amount compared to the 150 million tons to be mined. The benefit of additional ounces produced should far outweigh the additional drilling and blasting costs.

Jan 1, 2005

By R. Mckinstry, M. Rantapaa, T. Bolles

"Measurable improvements in throughput have been documented at Barrick Goldstrike due to increased ore fragmentation through efficient drilling and blasting techniques. A decrease in throughput at the autoclave, due to increasingly hard ore, was identified in early 2002. A team of individuals from the open pit and process areas worked closely on the Drill-to-Mill (D2M) Continuous Improvement initiative to ensure that it would address the needs of both groups, with the target of actually improving throughput in future years, despite the projected harder ores. A series of tests were conducted to determine if adjustments to drilling and blasting could positively influence throughput.Better fragmentation and a subsequent increase in mill throughput were achieved through the use of electronic caps for more precision and flexibility, as well as for allowing extremely fast shots; explosives with a higher velocity of detonation (VOD) to provide for improved shock energy; and improved distribution of the explosives by decreasing pattern spacing. Early tests indicated a significant increase in throughput when processing identified harder ore. It is anticipated that the total process throughput (hard and soft ore) will increase by 6 tph in 2003 due to the improved fragmentation of the hard ore.Barrick Goldstrike’s D2M initiative includes roaster hard ore (BWI>17), as well as autoclave hard ore (BWI>15). Approximately 6 million tons of D2M material were shot in 2003, a relatively small amount compared to the 150 million tons to be mined. The benefit of additional ounces produced should far outweigh the additional drilling and blasting costs."

Jan 1, 2005

By N. Hmidi, T. Yalcin, M. Papadakis, B. Hilscher

Mill tailings, containing iron sulphides in particular, pose an environmental concern since they constitute a potential source of acid mine drainage which can damage vegetation, harm soil and living organisms, and contaminate groundwaters. Proper disposal of acid generating tailings is therefore an important issue that must be addressed and resolved in a satisfactory manner. Placer Dome Canada operates a 4000 t/d gold cyanidation facility at Musselwhite mine, in northwestern Ontario, where the mill tailings have been classified as acid generating. This study was conducted to explore the effectiveness of froth flotation in removing the sulphide minerals from these tailings and producing a low-sulphur, non-acid generating material that could serve as a capping material for previously deposited tailings. Laboratory semi-batch flotation tests were carried out in accordance with an experimental design procedure, and a computer simulation program was developed to facilitate the evaluation of flotation performance. In this investigation, pH, collector concentration, and airflow rate were considered as the relevant flotation variables, and their effects were examined both experimentally and by simulation. Results have demonstrated that flotation can successfully desulphurize the Musselwhite mine tailings and render them non-acid generating.

Jan 1, 2004

By R. B. Throndycraft

"1. Belt-Drop Agglomeration Preferred at Heap Leach Operations. The agglomeration method now preferred at heap leach operations utilizes belt-drops along conveyors. Belt-drop agglomeration is being designed into numerous upcoming heap leach operations. It offers substantial capital cost savings over previously favored drum agglomerators. It has such significant operating and maintenance advantages that some drum agglomerators have been retired in favor of belt-drops.The majority of heap leach operations are now built with crushing included in the flowsheet. If crushing is included, belt-drop agglomeration can be added for almost no cost. The agglomeration equipment is simply a few conveyor transfers, designed to provide the tumbling and rolling action which forms the agglomerates. Controlled water sprays are needed at each of these agglomeration transfers. Cement or lime is added as a binder, to stabilize the agglomerates. This reagent is also needed to raise pH to safe operating levels.Addition of the pH control reagent before stacking the ore offers a reagent cost benefit. In the belt-drop mixing technique, the ore is intimately mixed with the lime (or cement). After stacking on the heaps, when the cyanide solution is sprayed onto the high-ph ore, very little cyanide is consumed. Without the pre-addition of lime or cement, the leach solution is sprayed onto neutral ore. The mixture of high-pH leach solution and neutral pH ore causes the solution pH to drop, releasing cyanide gas. This release is minor from a safety viewpoint, much less than dangerous, but the gas release is a costly waste of the cyanide reagent. Pilot-scale comparison tests were made at Pinson. Ore pre-treated with lime or cement showed 30% less cyanide consumption than untreated ore."

Jan 1, 1989

By H. P. Jacobi

"The last 25 years have seen tremendous economic pressure placed upon the base metal processor. Industry has responded with technological innovations that have contributed to significant reductions in capital and operating costs. Major changes in processing machinery and philosophy are highlighted for the main unit operations of a base metal mill. Changes in our attitudes on what is environmentally acceptable are also discussed.INTRODUCTIONNewton's law of motion paraphrased states that nothing will change unless there is a pressure to do so.Aase metal processing as a primary commodity related industry has been under severe economic pressure over the last 25 years. This has been brought on by over capacity from new operations in the L.D.C. 's, through material substitution in a host of traditional base metal applications and generally reduced world-wide economic activity. In addition to shrinking markets our collective environmental consciousness has raised effluent standards and workplace hygiene and the employee's as well as government's economic expectations of how much ought to be derived from ''nature's riches''.Industry has responded with technological changes which, it was hoped, would counteract the cost squeeze in which it found itself.I would like to briefly enumerate the major changes, as I see them, that have taken place in the main unit operations that form the normal processing chain for base metals.While the following paper will mention several brands of products, I would like to emphasize that these are the ones that I am most familiar with and is not to say that they are the only manufacturers which have contributed to changes. In fact it ls fair to say that all makers of mining and processing equipment have made improvements to their products, to a greater or lesser degree; they have had to, to still he in business in 1986."

Jan 1, 1987

By Bruce Mennie

PT Freeport Indonesia (PTFI) operates copper and gold mining operations in a mountainous area of the Mimika regency, near Tembagapura, Papua (formerly, Irian Jaya), Indonesia. The mining and concentrating operations typically produce 240,000 metric tonnes per day of Copper and Gold ore from the combined mining of an 80,000 tonne per day (ore) block cave operation (DOZ Mine) and a 160,000 tonne per day (ore) open pit mining operation (Grasberg Open Pit). The Grasberg Open pit mine will be complete in 2016 at which time PTFI?s operations will convert to Underground. Mining operations will transition from today?s mixed surface and underground operation to full underground mining over the next 6 years. This paper reviews the history of Redpath?s relationship with PTFI, beginning with a raiseboring contract in 1981 and evolving into vertical and horizontal development contracts of up to 37,700 equivalent metres of lateral development and 4,000 metres of vertical development in 2011. An overview of the current operations (PTFI?s Grasberg Open Pit and DOZ Underground Mines) and transition period (challenges for the transition from current to future underground mines) is presented with details of development of common underground infrastructure and future mines; Big Gossan Mine, DMLZ Mine, Grasberg Block Cave Mine, and the Kucing Liar Mine.

Oct 1, 2010

By Richard Morland

Some simple and fundamental objectives To challenge and inspire our people to embrace safety as a value ?A stand for safety as a value ?A stand for our people ?A stand by our people ?Prevent harm to our people ?Eliminate suffering for individuals, families, friends, colleagues

May 1, 2010

By D. M. Wyslouzil

"This paper was prepared for presentation at the 16th Canadian Mineral Processor's Annual Meeting, Ottawa, Ontario, Jan. 17 to Jan. 19, 1984.This paper gives an account of the development of treatment procedures for the differential flotation of refractory copper-zinc ores. Special references are made to the effectiveness of various zinc depressants and their combinations.Studies carried out on refractory copper-zinc ores demonstrated that conventional zinc depressants such as cyanide and zinc sulphate were not particularly effective when secondary copper minerals were present in the ore; the flotation activity of sphalerite was enhanced in the presence of cyanide.Among the various zinc depressants evaluated, the following depressant combinations were found most effective: Zn(OH) 2-S02 , 802-CaO, Na2S-Na2S03-S02, Na 2 S-S02 and Na 2S-S0rDS22.The practical application of any of these systems depends on the type of ore treated and other conditions such as pH, levels and points of collector and depressant additions.In this paper the effect of each depressant combination on different ores is described with reference to the selection of collectors."

Jan 1, 1984

"It is projected that the reactivity of acid generating tailings and waste rock can be minimized by reducing the access of oxygen by placing these materials under water in natural or manmade lakes. A project under the MEND and B.C. AMO Task Forces has been in progress for four years to evaluate active and historic tailing sites in B.C. and Manitoba. The sophisticated geochemistry studies conducted on the interstitial pore water has illustrated encouraging results which are discussed. The additional studies which are needed to complete the scientific database for the study sites, for achieving regulatory and public approval and for the engineering of application of this method of control are outlined.IntroductionWorld wide research effort is in progress to find the solution to the acid mine drainage problem. A great deal is known about acid mine drainage but much work is required to find economic and effective approaches to the problem. Two coordinated programs have been initiated recently in Canada: the National Mine Environment Neutral Drainage (MEND) program and the British Columbia Acid Drainage Task Force.Disposal of tailings materials under a water barrier such as a natural lake, is thought to be one solution to prevent acid generation by preventing oxygen and bacterial action on the sulphide surfaces. The deposition of reactive tailings materials under water in natural lakes has been used historically at various mines in Canada. However, there has never been a thorough review of the long and short term impacts of historic sites which may provide crucial information to understand the physical, chemical and biological processes which are taking place.This paper provides a general overview of a series of studies which examine the general biophysical characteristics and the sediment geochemistry of four lakes where subaqueous disposal has been or is currently being used for acid generating tailings. The subaqueous disposal studies have been conducted from 1989 through 1991 and were initiated and supported by both research task forces. The objectives of this paper are to summarize the history and the background information of the studies conducted, the general results obtained from each lake, an overview of the major collective results and the additional work which is required to achieve the final objective of developing criteria for applying this technology in the industry."

Jan 1, 1992

By Alain Blouin, Mohamad Sabsabi, Aissa Harhira, Paul Bouchard, Greg Lithgow

"The objective of this study was to demonstrate the application of Laser-Induced Breakdown Spectroscopy (LIBS) to the continuous analysis of online monitoring of Al, Mg, Ni, Mn, Si and Fe in nickel ore limonite and saprolite slurry samples. Analysis was performed on slurry samples in air at atmospheric pressure. Two pure samples of limonite and saprolite were used. Mixtures of the two samples in varying proportions were used to build calibration curves, study the influence of solid/liquid ratio, and evaluate short and long term reproducibility. The LIBS measurement of these elements is independent of the water content (from 70-85%, the range allowed by our setup). Repeatability of the measurement and long term reproducibility (from day-to-day) were below 1.2 % and 2% respectively for all the elements studied in our conditions. The results obtained showed that an industrial LIBS analyzer could provide the chemical composition of the six elements Al, Mg, Ni, Mn, Si and Fe within 1-2 minutes.IntroductionThe metal-producing industry faces the major challenge of increasing productivity, reducing costs, and maximizing benefits from existing equipment. By pyrometallurgy, metal making involves the basic steps of charging the furnace, melting the charge and refining. By hydrometallurgy, the metal refining is carried out through the dissolution of the metal by chemical reaction and electrolysis. During refining either by pyrometallurgy or hydrometallurgy, it is critical that operating parameters be adjusted and controlled so that the chemistry of the melt or the solution is within predetermined limits. Presently, the complete turnaround time for sampling, sample transfer, analysis and communication of the results to the operators is often 30 minutes or more."

Jan 1, 2016

By Gregg S. Hill, Bert J. Huls

"This paper on coarse particle recovery (CPR) summarizes a process to capture coarse particles that are not recoverable by regular flotation. Several porphyry copper operations in the world operate analogous circuits that recover non-floated copper from tailings; however, the case presented here is unique in that extensive underlying test work has allowed us to elucidate some fundamental principles behind recovery enhancement. This paper discusses an overview of the flow sheet that is proposed to Minera Escondida Ltda., the nature of copper in the feed to the CPR circuit, and the various unit operations within the recovery circuit. Details of the technology behind each unit operation will be presented in later publications.INTRODUCTIONSince 1996 BHPBilliton and MEL (Minera Escondida Ltda.) have developed a process to recover copper from coarse particles in the rougher tailings. Copper recovery from fresh tailings is not new. Several operations in Chile, such as Chuquicamata, El Teniente (AMEC, 2003), Mantos Blancos and others have operated various forms of tailings circuits. Both Chuquicamata and El Teniente practice cascade flotation scalping off froth containing fine copper particles after allowing sufficient retention time, air inducement and, sometimes, additional reagent addition. Chuquicamata tailings are not segregated but floated in sequential cascade and conventional large cell arrangements. At the Valle Central operation of El Teniente a coarse fraction of mill tailings is ground and floated, with the rejects recombined with fine tailings and subjected to cascade flotation through a sequence of concrete launders as the tailings flow towards their final deposition area. Mantos Blancos cyclone the rougher tailings and blend the underflow with scavenger concentrate from elsewhere in the principal circuit prior to flotation in Wemco Cells. Kemess in BC, Canada operates a 160 m3 Outokumpu cell to reduce the tailings sulfur content (Rasmussen, et.al, 2004)."

Jan 1, 2005

By Jean-Sébastien Kroll-Rabotin, Éric Climent, Florent Bourgeois

"Falcon concentrators are enhanced gravity separators designed for concentrating fine and ultrafine slurries. The Falcon UF model is unique in that it is dedicated to beneficiation of ultrafines, one key feature being that it does not make use of any fluidisation water. In a former study, we investigated the physical mechanisms that govern the transport of ultrafine particles (in the range 10 to 80 µm) inside Falcon UF concentrators, and concluded that separation efficiency is governed by differential settling. Initially, we derived and published a predictive model of the partition function under dilute conditions. The present paper proposes an extension of the initial model to concentrated ultrafine suspensions for application to industrial scenarios. The paper discusses how hindered settling has been added into the initial model to account for solid concentration effects. The modified model is tested against experiments carried out with a laboratory scale UF Falcon concentrator from dilute conditions up to 30 vol%. A good agreement between measurements and model predictions is obtained, which confirms that our hypotheses about the physics of separation inside a UF Falcon separator remain valid even at high concentrations.INTRODUCTIONThe Falcon concentrator is a fast spinning bowl that is fed at its centre of rotation. It uses centrifugal force to separate particles that are transported inside a thin liquid film that flows upward along the inclined wall of the bowl (McAlister and Armstrong, 1998). Due to differential settling, dense and coarse particles are concentrated inside the bowl whereas light and fine particles are rejected with the overflow stream. The fast rotation speed of the bowl yields high centrifugal force several hundred times the attraction of Earth. Despite the thinness of the liquid film (between 100 µm and 1 mm with a Falcon L40) where separation takes place, the Falcon concentrator can treat high flowrates (up to 30 L/min). At the bottom of the bowl, an impeller transmits the bowl rotation to the feed, which drains upward by centrifugal force as soon as it hits the base of the spinning bowl (Figure 1)."

Jan 1, 2011

By Rayleen Riske

Why do we look for better reconciliation when times get tough? Why wait? Mine reconciliation should be a priority throughout the good times too. In fact, with good reconciliation, those good times are going to be even better and will help pave the way to success through those preventable bad times. Reconciliation throughout the entire mining value chain requires the capture, validation, and analysis of copious amounts of data. This task can be daunting for a team in a small mine, let alone reconciling across a suite of large mines. This paper will outline the different ways we can reconcile across the value chain, why we should reconcile over differing periods of time and how Snowden?s solution to proving reconciliation can be a simpler, reliable and transparent process. Snowden?s Reconcilor is proving to be a valuable tool on any mining scale, by capturing, validating, sorting and reporting data for timely decision making by the site geologist through to corporate management. By instigating vigorous reconciliation, you are setting your mine up for the future. Not only will you have the means to analyse your current processes and measures, but you will have the opportunity to identify and improve your mine?s performance from the resource model through to the final product.

May 1, 2010

By Timothy R. Eby

"The Wabush Mines project was formed in 1956 to develop a large iron ore property in Western Labrador. The town of Wabush along with the mining and concentrating facilities are located 640 air miles from Montreal, and 734 air miles from St. John's. The operation has been in production since late 1964.While mining and concentrating operations are located in Labrador, the pelletizing facilities are situated 275 miles south at Sept-Iles, Quebec. Dedicated in 1965, Wabush produces six million tons of high quality iron ore pellets annually. The company employs 1, 550 people at Wabush and the Pointe Noire plant at Sept-Iles.Wabush Mines is an unincorporated joint venture of three companies -The Steel Company of Canada, Dominion Foundries and Steel Ltd. and the remaining 58% by the Wabush Iron Co. Ltd. Wabush Iron Co. Ltd. is in turn owned by six companies: The Youngstown Sheet & Tube Company, Inland Steel Company, Interlake Inc., Wheeling Pittsburg Steel Company, Finsider International S.A. and Pickands Mather & Company which is also managing agent.The town of Wabush is set in a remote part of Northern Canada accessible only by rail and air transportation. But this in no way has hindered the growth and development of the area. Modern housing units, shopping facilities, airport and of course, recreational facilities are all patt of every day living amenities, an accepted aprt of southern communities, but quite unique for northern isolated mining localities."

Jan 1, 1978

By C. O?Connor

With ever-increasing global demand for mineral resources, numerous mines are moving towards developing and mining deeper, more complex and lower grade ore bodies. In many cases, mass mining methods (e.g. block caving) are being considered to deal with deeper, lower grade deposits. The body of practical knowledge, however, related to the impacts mass mining methods have on the surface environment in terms of rock mass response, subsidence, etc., is limited, imposing both economic risks to the mine and safety risks to mine personnel. This paper presents the framework for and preliminary results from a large collaborative research initiative between Diavik Diamond Mines, Rio Tinto, the University of British Columbia (UBC) and Simon Fraser University (SFU). The project involves the integration of available subsidence, rock mass, mine operation and monitoring data, together with the advanced application of combined finite/discrete-element modelling codes capable of simulating fracture behaviour, cave propagation and surface subsidence above block cave mines. The main objective of this work is to develop advanced numerical modelling methods to characterize complex rock mass behaviour above block cave mines. The research will also include the study of rock deformation mechanisms associated with the transition from surface to underground mining and the potential interaction between simultaneous open-pit and underground mining operations.

May 1, 2007

By C. Larsen, E. Gratch, B. Flintoff, R. Bradburn

"In 1973 Brenda Mines Limited first investigated the potential use of a process computer to aid in the development of a control system for the concentrator grinding circuit. This initial study and its results are reviewed (1) in a previous paper.Since that time the computer system and its applications have been expanded. After the initial success of grinding circuit control, a second process computer was purchased to function as a back-up device. The two processors are currently operated in a foreground-background mode which allows extensive use of the computing facility for engineering and development work as well as operator training.Because of the relative ease of expansion, the computer has been incorporated into a flotation control system as well as an electrical peak power savings program.It is the purpose of this paper to review the successful application:; of the process computer and to indicate applications which are envisaged for the future."

Jan 1, 1978

By F. Flynn, P. Downey, G. Ritson

"Bell Creek Mill which has been in continuous operation since 1987 has undergone numerous operational changes in the past three years. The addition of over 2. 5 million tons of resource at over 13 git from Hoyle Pond Mine precipitated an expansion program for the Bell Creek Mill. This paper discusses the major changes that have occurred over the past two years to increase throughput and efficiencies. In addition, the refractory ore treatment options are also discussed.IntroductionThe Bell Creek Mill is located in the Timmins Goldcamp approximately 8km NE of porcupine Ontario. (Fig I.)The mill was originally constructed by Camamax in 1987 to treat the Bell Creek ore at a design throughput of 350tpd. The flowsheet (Fig 2.) consisted of two stage crushing, grinding, thickening, leach and drum filtration with gold recovery by Merrill Crowe.As ore depleted at Bell Creek, the Mill was purchased by Falconbridge to process ore from their Hoyle Pond property. Kinross purchased the Hoyle Pond property and Bell Creek Mill from Falconbridge in 1992.The successful exploration program at Hoyle Pond has led to several expansions and process design changes, with further changes planned over the next twelve months.In 1994, the mine produced 61,865 oz. of gold at an average cost of 197US$ per oz. In 1995 production was 91, 611 oz. at a cost of 187US$ per oz. Projecting the nine months ended September 30, production for 1996 will be 155,000 oz. at a cost of 165US$ per oz.In early 1997, the CIP expansion will be complete, with a target of 175,000 oz. at a cost of 176US$ per oz for 1997. The mill throughput will have increased from 400tpd to 1500tpd between 1994 and 1997.The changes to Bell Creek since 1994 have been numerous with very little of the existing equipment still in operation. The total cost of the expansion to date is 15 million C$. This paper discusses the major projects carried out during in this time. The focus will be to highlight the justification of each project, the design and engineering, some of the initial start-up problems and solutions.Figure 3 shows a plan of the existing mill facility together with the various additions that were carried out."

Jan 1, 1997