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By Norman Lecuyer, Jacque Nantel

"The Chadbourne Project, located within the limits of the town of Noranda, Quebec, will make use of backfill materials to fill the voids left by the mining of stopes and pillars. A series of tests were conducted on different mixtures of slag and pyrrhotite tailings materials to evaluate their properties. The tests are described and some pertinent results are given in the paper.IntroductionThe Chadbourne Project is located in the centre of the Town of Noranda, Quebec, with houses as close as 120 m from the blasting operations. The ore is mined using the vertical crater retreat method. The voids left by mining activities will be filled. A program of pillar recovery will follow.Considering the proximity of houses and the need to recover pillars, the backfill program must be carefully laid out. No subsidence can be tolerated on surface.With these objectives in mind, a test program was undertaken by Nantar Engineering Limited and Queen's University to evaluate the possible ba ckfilling alternatives available to Chadbourne. One of the possibilities retained was the use of a backfill composed of broken slag material from the Horne Smelter and pyrrhotite tailings deposited on the Horne's pond a number of years previously.The back fill used at the Horne Mine until the mine closed in 1975 was composed of a mixture of 97% granulated slag and 3% pyrrhotite tailings. The tests leading to its use underground at the Horne Mine were described by Patton in 1952. The structural properties of the Horne backfill were ""intuitively"" known; it was agreed by all at the Horne Mine that the backfill was behaving remarkably well. Some were labeling it ""the best backfilling material in the world"". Its strength was said to be that of a weak concrete. All of the preceding indicate that the Horne backfill had never had its structural and other properties determined in the laboratory."

Jan 1, 1983

By Jan Rosenkranz, Anders Sand, Lisa Malm, Nils-Johan Bolin

Within flotation technology the general trend is towards very large cells. Scale-up is usually done by postulating geometrical similarity, which implies keeping the aspect ratio constant when increasing cell volume. Consequently, the design of flotation circuits typically involves several cells of identical geometry within a bank. Using a few standard sizes in a flotation plant simplifies design, manufacturing and maintenance of the cells, but does not necessarily guarantee optimal performance and selectivity of the flotation process. Geometry parameters for a given cell volume that influence flotation cell performance include cell height, which causes changes in the hydrostatic pressure and suspension hydrodynamics, and also influences the travel distance of particle-bubble agglomerates as well as the homogeneity of the mixing. Also the thickness of the froth layer depends on the aspect ratio of the cell. The objective of this work is to gain a better understanding of material distribution and properties within a flotation cell and, based on this information, elucidate how alterations of the cell geometry can influence separation efficiency. For this purpose systematic measurements and analyses of the spatial distribution of the different phases within a 160 m3 flotation cell have been carried out with a particular focus on an industrial, low-grade copper ore beneficiation process. The concepts for sampling at different vertical and lateral positions of the flotation cell are introduced. The results from the experimental work give an understanding of internal material distribution within flotation cells. Based on the measured phase distribution and concentrations as well as particle properties at various positions within the cell, the implications for an optimized scaling and design of individual flotation cells within a flotation circuit are discussed.

Jan 1, 2016

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

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

Jan 1, 1980

By M. S. Moats

"The effects of commercial copper electrorefining additives (glue and thiourea) on the electrochemical removal of bismuth are of importance in copper production. It was found that Bi(III) electrodeposition occurs readily from acidic sulfate solution via a diffusion-controlled quasi-reversible reduction. The diffusion coefficient of Bi(III) was measured and found to be less than reported values of copper in similar solutions. The presence of thiourea and/or glue was found to accelerate or de-polarize Bi(III) reduction on stainless steel as compared to the inhibition or polarization of Cu(II) reduction. The additives also inhibited the dissolution of the Bi-Cu co-deposit during cyclic voltammetry. During short term deposition studies, the additives increased the concentration of Bi in co-deposited Cu-Bi products from solutions with low concentrations of Cu (<2 g/L). Bi deposition was significantly suppressed by increasing the Cu(II) concentration in the solution. The formation of a copper layer on the stainless steel electrode appeared to significantly suppress the reduction of Bi(III). This study demonstrates that glue and thiourea depolarize the deposition of bismuth on stainless steel. Therefore, the additives could be used to improve Bi impurity removal during third stage liberation.INTRODUCTIONThe production of high purity copper has been steadily increasing due to the wide application of the metal and its alloys in electrical and electronic products, infrastructure construction, industrial machinery and equipment, general products and transportation (Moskalyk et al., 2003). Most high purity copper is manufactured from copper sulfide mineral concentrates and/or scrap via a pyrometallurgical process followed by electrorefining (Navarro et al., 1999). During the electrorefining process, cast anodes of 99-99.5% purity are electrochemically dissolved into an acidified copper sulfate solution while high purity copper (>99.99%) is plated on stainless steel blanks or copper starter sheets (Davenport et al., 2002). The control of cathode deposit growth (purity and morphology) while maintaining a high current efficiency is of significant importance for copper refining (Ilkhchi et al., 2007). At typically applied current densities for industrial copper electrorefining, mass and charge transfer play important roles in the quality of cathodic products (Hiskey et al., 1998). If the real current density at some surface points is substantially higher owing to uneven current distribution, then rough spots can and will grow faster leading to nodules (Suarez et al., 1992). Nodulated deposits tend to capture solution and anode impurities (slimes) resulting in unacceptable cathode quality (Afifi et al., 1987). Furthermore, these nodules can grow until they eventually contact the anode leading to short circuits and current efficiency reduction (Ilkhchi et al. 2007)."

Jan 1, 2016

By G. J. Desroches

"In order to improve zinc plant productivity, areas of low efficiency were identified. As a result, solution purification was improved, additional dust precipitator capacity was made available and a new zinc casting plant was installed. The effects of these and other changes are discussed and the expenditure and benefits reviewed. HistoryThe operation of the Flin Flon metallurgical complex including an electrolytic zinc plant commenced in October 1930. The design of the zinc plant was based on that of the Commonwealth Mining and Smelting Company at Trail, British Columbia, the Anaconda Great Falls Montana Plant and the Electrolytic Zinc Company plant at Risdon, Tasmania.The plant began with a design capacity of 60 tons per day and currently produces 255 tons per day. Since plant start-up, approximately 3.5 million ton s of zinc metal have been produced, most of it exceeding special high-grade specifications.IntroductionThe facility incorporates the basic process steps of roasting, leaching, purification, electrowinning and casting. Figure I details the flowsheet. During the late 1970s, management recognized that in order for the zinc plant to continue operating, it was necessary to introduce cost-effective practices.Study groups, consisting of design engineers and operations personnel, were formed to investigate the details of plant revisions.The objectives were to improve productivity by reducing manual labour, reducing energy usage, increasing zinc recovery, increasing metal output and reducing costs.This paper details the changes made during the period 1979to 1986 and shows how these changes have affected the productivity and economics of the zinc plant operation."

Jan 1, 1988

By J. E. Marshall

"The concept of employing a project management team to coordinate all aspects of the construction of a new resource development has gained wide acceptance. This team can be formed from within the staff of large mining companies or contracted from major engineering firms and consultants. The mandate of the project managers usually terminates on successful startup of the operation. For frontier mineral developments in the Canadian Arctic or in the developing countries, startup and the initial year of operation represents the period in which the project is most vulnerable to technical, political and managerial problems. A complete change of the management team or the retention of the construction project managers and the resulting cost combined with the breakdown of organizational accountability within the operating staff .are unnecessary management problems.Independent project management services provide the commitment necessary to sustain the continuity of management through all project phases. Efficiency and the ability to make decisions quickly are characteristics of the many successful small mining companies. These qualities are necessary in the project management group, which will be responsible for up to 90% of the preproduction costs.Continuous project management in the construction and operational phases of a mineral development are common in the iron ore industry, but remain anomalous in the base metal, energy mineral and industrial mineral fields.The Nanisivik project on Baffin Island in the Canadian Arctic is used to illustrate the advantages of total project management through construction and operation.Total project management has further potential for foreign interests and financial and utility organizations desirous of participating in the Canadian mining industry, but with no direct involvement in the construction or operating management. Participation agreements in the operating phase of a project can be negotiated to have management fees related to both the production and the profits of the enterprise."

Jan 1, 1980

By Robert MacPhail, Louis Racine, Bret G. Cousins

"Sodium Isopropyl Xanthate is employed in a wide variety of sulphide flotation procedures due to the specificity over other xanthates and the cost savings over other sulphide collectors such as thionocarbamates, xanthogen formates and dithiophosphates. An investigation carried out by Tennants Research Technology Applications (TRTA), has produced a chemically enhanced SIPX that has shown all the advantages of normal SIPX along with improved recoveries.Currently, FLEX 31 is manufactured at the Prospec Chemicals xanthate plant in Fort Saskatchewan, Alberta, Canada. Prospec, founded in 1983, produces approximately 4500 tonnes of xanthates per year and is presently undergoing expansion to produce approximately 6000 tonnes. The proprietary process for FLEX 31 is a new addition to plant operations that include the production of xanthates, thionocarbamates and xanthogen formates.This paper will cover the testwork on the zinc flotation circuit at the Louvicourt Mine in Val d'Or, Quebec. This testwork indicated that FLEX 31 could replace SIPX due to the ability of the FLEX to improve zinc flotation kinetics without adversely affecting final concentrate grade. FLEX has presently replaced SIPX in the zinc circuit at Louvicourt.BackgroundThe Louvicourt deposit is hosted by greenschist facies Archean volcanic rocks located in the southeast portion of the Abitibi Greenstone Belt. In the Val d'Or area, the volcanic rocks form an east-west striking, steeply dipping and south-facing sequence composed of thick mafic and ultramafic flows of the Lower Malartic Group.The joint venture has three partners-Aur Louvicourt Inc. (30%), Novicourt Inc. (45%) and Teck Corp (25%). Aur Resources holds 30% interest through Aur Louvicourt, a wholly owned subsidiary and is the operator of the project. Novicourt Inc. is 60.9% held by Noranda.Approximately 75% to 85% of Louvicourt's revenue comes from the sale of copper; 10% from gold (in the copper concentrate); 7% from zinc and 3% from silver (also in the copper concentrate) The copper at Louvicourt is fairly ""fast floating"". About 60% of the copper in the ore can be concentrated in the first flotation cells with feed grades of approximately 4% copper.The initial testwork and pilot trials had indicated that it would be difficult to achieve zinc grades over 52% and recoveries would have to be kept at a level amenable to salable concentrate grades. The actual mill results, with a fine regrind, achieved zinc grades of 55% to 56% at about 75% recovery."

Jan 1, 1996

By R. W. Pugh, S. L. Ma

"High carbon rods are typically used as the grinding media in rod mills. Usually an AISI I 090 grade of steel is used which provides the high hardness needed for abrasion resistance and sufficient toughness to prevent rod breakage.Work to improve performance in the past has mainly concentrated on increasing the hardness for improved abrasion resistance. This has been accomplished by adding alloys to the steel which uniformly increase the hardness across the rod section.However uniformly increasing the hardness of the rod produces a more brittle product and at high hardness l1evels can lead to rod breakage problems. Heat treatment processes can be used to selectively increase the surface hardness to high levels while maintaining the core at lower hardness levels to give a product that wears slower without breakage. AltaSteel has developed and mill tested a higher hardness heat treated grinding rodThis paper describes the development of a simple model to predict performance improvement with different hardness profiles and the AltaSteel heat-treated grinding rod process. Mill characteristics of the Endako operation are summarized and predicted performance improvements based on hardmess are compared to the approximate 25% achieved in trials running since July, 1991 at this mill. Early results of other mill trials are also presented.INTRODUCTIONAltaSteel, in Edmonton is a major supplier of grinding media. We have a strong desire to continually increase the quality and performance of our products and thereby improve the efficiency of our customers' processes. In the area of grinding rods, we wanted to produce a product with a significant improvement in wear rate. Second to energy, rod consumption usually represents the next highest cost in processing. This paper presents our development of a heattreated grinding rod that has reduced consumption by about 25% in trials to date."

Jan 1, 1993

By H. Bannach

"This paper focusses on what seem to be the leading indicators of prosperity in the minerals industry during this decade: the geographical distribution of deposits, environmental impact, capital allocation and acid consumption. There is a potential for meeting environmental criteria at a reasonable profit margin, but those with limited acid demand within economic range will face hard times to meet growing environmental concerns, resulting in additional mine closures. At the other end, those with old waste dumps who are thinking about smelting capacity additions will need capital influx at a much larger rate than ever before. All things considered, a change should be made in the way the world&apos;s copper reserves are computed, because there is a growing need to internalize these effects back to the ore blocks before a meaningful estimate of reserves becomes available.IntroductionThe copper industry has undergone several changes during the past decade, many of which were expected to take place because they rel1ect the economics of ageing mines. However, many others took place that shocked the industry because they were not completely under control. The focus of this paper is to rel1ect on those changes, and on market expectations for this decade that somehow depend on their impact.To review the prospects for new mine developments and expansions from an industry perspective to a full extent, it would be necessary to consider not only the deposits themselves, but also geographical constraints, environmental constraints, labour composition, technology development and use, the availability of capital, ownership issues, and integration within the industry. This paper, however, will concentrate on only some of the key elements that are believed to playa major role in shaping the market in the decade that has just begun. These elements, all interconnected, are:"

Jan 1, 1992

By K. Wongpreedee

Recovery and recrystallization of Au wire can degrade strength and alter conductivity properties during exposure to elevated temperature. Au Deformation Processed Metal Metal Composites (Au DMMC&apos;s) are being developed for electronic applications requiring high conductivity and high strength. This paper discusses the relationships between microstructure, strength, and resistivity of Au DMMC&apos;s. It also presents the results of a recent study on the elevated temperature stability of Au DMMC&apos;s of several compositions. Au-7 vol %Ag, Au-14 vol %Ag, and Au-vol 7%Pt DMMC samples were prepared by a powder metallurgy technique. All specimens were processed into wire by extrusion, swaging, and drawing. The smallest final diameter of these wires was 120 ?m. Thermal stability was analyzed by electrical resistivity measurements to determine the relation between transformation rates and time at elevated temperature. The extensive deformation used to produce these composites reshaped the initially equi-axed powder into filaments that are 30 to 100 nm in diameter and 16 to 180 mm in length. The small filament diameter confers high strength on the composite. The high conductivity can be explained by electrons flowing parallel to the filamentary microstructure aligned with the wire axis. Using the Avrami and Arrhenius equation relationships, it is possible to predict the times and temperatures needed to achieve various degrees of homogenization. The Au DMMC&apos;s were found to have good thermal stability compared to conventional coldworked Au interconnection wires. Although these composites will revert to solid solutions if exposed to high temperatures for prolonged time periods, their relative stability is sufficient to allow them to maintain their twophase microstructure during the anticipated lifetime temperature profiles of many products.

Oct 1, 2003

"ChairmanThis part of the discussion is intended as an exchange of information between those who have installed rubber liners in their mills and a means of others to get information that may help them decide if rubber liners would be applicable to their mills.To start the discussion and to relate it to the previous section of this symposium Mine Equipment Co. Ltd. have supplied some graphs that will give some idea of the noise suppression that may be expected from the u.se of rubber liners instead of steel. The figures used in preparing the graphs came from installations of rubber liners in Sweden.L. Strah - Mine Equipment Co.The graph, Figure 1, shows on the bottom the octave band range. The noise level generated by the steel liners is represented by the dotted line and lies within the shaded area where it is considered that hearing damage may result. The solid line represents the noise level generated by rubber liners in the same mill and you will see it is below the shaded area. Although it is not marked on the graph I think the decibel range is from 7 5 to 115. The next one, Figure 2 which shows the relative noise levels generated by steel balls and pebbles with both steel and rubber liners shows the decibel range."

Jan 1, 1968

By Chris Brothen

The introduction of new technology in mine operations has provided real opportunities for increased efficiencies and production gains which translate into enhanced profits. Computing and network technology usage has become integrated into surface mining operations and on average these investments in technology have proven beneficial for efficiency and productivity improvements. Embracing new technologies however, does not guarantee positive results. The expectations or improvements derived through the technology must be confirmed and clarified well before implementation. Tire Pressure and Temperature Monitoring Systems are an excellent example of an existing technology that can provide full time automated performance measurements of tires operating under harsh conditions and environments. Prompt warnings or alarms signaling when a tire has exceeded operating capacities will provide savings through lowered maintenance costs and increased productivity. To truly quantify the projected savings in tire life, fuel consumption, and increased levels of production, all costs associated with the technology, both direct and indirect must be considered. Apart from the initial cost of the system implementation, ongoing maintenance and support costs must be considered as well as the costs of system integration into existing mine operations

May 1, 2008

By K. Fumimura, T. Nishimura, M. Kohno

When applying numerical techniques to problems of deformation of rocks, the body to be analyzed is divided into small portions and is represented by a system of points linked together with the neighboring points. In the so-called distinct element modeling, the particles in the system are directly connected by springs and a contact law is used to specify forces on the particles to simulate the mechanical behavior of the body. The relation between the spring stiffness and commonly measured material properties, such as the Young’s modulus and the Poisson’s ratio, should be known a priori. For the general case of a random packing of particles, the relation is found by means of a process in which a system of particles and set of parameters are prepared to simulate a set of specimen-size test and then the input parameters are chosen to match the measured material properties. The validity of the numerical result is only demonstrated by comparison model behaviors with the measured responses. The process includes trial-and-error manner, therefore, no model is complete to reproduce the mechanical properties. In this paper, a relation between the spring stiffness and the elastic constants; the Young’s modulus and the Poisson’s ratio, is introduced to a three-dimensional distinct lattice spring method. Two simple numerical examples will be presented to demonstrate the performance of the method with the procedure for the determination of the spring stiffness.

Jan 1, 2015

By George R. White

"The Phalen Colliery, the Cape Breton Development Corporation&apos;s flagship, is now producing thermal and metallurgical grade coal in Eastern Canada&apos;s Sydney Coal Field. The colliery is a drift mine operating under the waters of the Atlantic Ocean. Improved mechanization, including a 2200 tonne per hour cable conveyor, and the introduction of modern retreat longwall mining methods as part of the Phalen concept are now paying off in better productivity and low operating costs. Geological conditions within the coal field are consistent with plans for ever greater outputs in the 1990s. Although much of the current production improvement is related to uprated machine capacity and simplified mines planning there is potential for even further development in the areas of maintenance, process control and engineering. Human resource development will also be a key factor. These programs are now well under way and Phalen Colliery is poised for top results in the 1990s. Comparison of the CBDC&apos;s top producer with similar operations elsewhere in the world, quantifies that potential.IntroductionAn exciting new mining project which has recently started production on Canada&apos;s East Coast has been conceived and designed to be one of the most modern and productive coal mining operations in North America.As with all mining operations, the business is basically that of material transportation. Daily, the product is transported many kilometres from the underground face to the surface and then to washing facilities. Men, materials and equipment are transported to and from the surface and the operating faces and services, such as electrical power, ventilating air, fresh water, discharge water, communications and compressed air are supplied throughout the operation to cover operating requirements. On all accounts the operation has been designed to take advantage of the latest proven technology."

Jan 1, 1990

By G. R. Guillet

"Bricks made from local Paleozoic shales, and floor and wall tiles made from imported clays, both established record production volumes in 1985 and are the strongest segments of Ontario &apos;s clay products industries. However, renewed interest in traditional materials also supports a good market for clay flower pots and flu e liners, and innovative processing studies are showing promise for possible new production of clay roofing tiles. This paper reviews the highlights of a comprehensive study of Ontario&apos;s clay products industries, completed in 1986. IntroductionFor some years now, Ontario&apos; s clay products industries have been unspectacular in their attempt to cope with the recent recession and the impact of alternative materials. But a strong demand for bricks in recent years has done much to dispel the gloom.Bricks, drainage tiles, sewer pipes, flue liners, structural and partition tiles, and flower pots have been commonly referred to as ""heavy"" clay products, and they have been based largely on local clays and shales. To this list might be added expanded aggregate and mineral wool. Clay refractories, sanitary ware, electrical porcelain , art pottery, and floor and wall tiles are not considered heavy clay products, and are commonly made from a variety of ceramic materials, many of which are imported.Production facilities for heavy clay products often began in Ontario as small family enterprises, using whatever clay was available locally to supply the local market with building bricks and other clay products needed for construction. Improved road systems increased the market range for these plant s, and new technology and industry standards resulted in gradual"

Jan 1, 1988

By Douglas H. Silvey

"The historical transformations in fire -resistant conveyor belt compositions in the past 20 years have been influenced by factors of material cost, changing flame and burn test requirements, material replacements, adhesion and oil resistance considerations, increased responsibility and legal liability. Specifically, this has resulted in a swing from neoprene-cotton belts to S.B.R. blends and synthetic fibre carcasses, and tighter quality control and documentation of test data.Flame dynamics are discussed and the function and performance of the multiple types of flame-resistant additives in the flame front are presented. Specific flame and burn test requirements are described. The belt manufacturers&apos; requirements and criteria in selecting the types of flame-resistant additives are presented.The author will describe the composition of the types of flame-resistant compounds used in a practical production, the belts that are available on today&apos;s mark et and future developments in requirements that may further transform the composition of fire-resistant belts.IntroductionThe historical transformations of conveyor belt compositions in the past two decades have been based on factors common to those leading to changes in man y organic compositional products. These factors are material cost, new materials, the customer&apos; s changing requirements, government regulation s and increased manufacturer&apos; s liability.As a basis for understanding the product, I will provide a brief breakdown of the conveyor belt composite. Figure 1 represents a cross section of a typical belt. A skim rubber coats each fabric ply of the belt carcass and is of a different rubber composition than the outside layer of rubber which forms the cover. This outside cover layer is designed to protect the belt from environmental factors such as heat, oil and abrasion, and other factors involved in the service condition s under which the belt will operate. In the case of fire-retardant belt s, both the skim coat encapsulating the fabric plies and the outer cover must contain sufficient fire retardancy to overcome the contribution to burning of the decomosition products of the fabric."

Jan 1, 1982

By D. E. M. Plaumann

"The wet grinding of asbestos has attracted the attention of engineers for many years as a means of improving fibre liberation from the ore. Today, added impetus for wet grinding has resulted from a need to minimize worker exposure to asbestos dust in conventional dry mills using air, as well as a need to provide a cleaner, technically superior fibre for use by product manufacturers. However , high viscosities of asbestos slurries create transport and grinding difficulties which have been a factor impeding use of a wet grinding process.Laboratory evaluation of reagents to reduce viscosities of asbestos slurries found that one reagent, XFS-4272.00, reduced the viscosity of a 35% (by weight) slurry by 75%. The impact of XFS-4272.00 on actual grinding parameters were evaluated using a pilot plant rod mill. Slurries containing 78% solids and XFS-4272.00 were successfully milled and asbestos fibres from that milling compared favourably in liberation and relative surface area to asbestos fibres obtained from milling a 4% slurry without additives.IntroductionAlthough the use of asbestos has been declining over the last few years, the large deposits of chrysotile in eastern Canada (Quebec in particular) remain very important. Asbestos production in Canada stands ninth in volume for mineral production with over 740 000 tonnes produced in 1985. Of this quantity, 722000 tonnes were exported with a value of $446 million . Canada is second in world production of asbestos behind the U.S.S.R ."

Jan 1, 1988

By M. R. Babcock

"The Rabbit Lake story began in the late sixties and will continue well into the twenty-first century. It is a story of success, of multiple ore body discoveries, of unique systems, and new methods made possible through innovative and state-of-the-art design. Two quite different geological systems host the five ore bodies mined, or slated to be mined. These two systems have yielded two distinct ore types, each with characteristic mineralogical properties and each requiring its own specific mill circuit.Emphasis on communications and our unique systems have led to a satisfactory and fulfilling work environment resulting in the historically low employee turnover which has contributed to the operation success.A comprehensive environmental study after twelve years of operation has given the Rabbit Lake Operation a completely clean bill of health. INTRODUCTIONRabbit Lake can be described as Saskatchewan&apos;s first highgrade uranium mining operation, which set the stage for the province&apos;s current role as the leader in uranium mining throughout the western world. The importance of the Rabbit Lake operations - past, present and future.LocationThe Rabbit Lake operation is located in northeastern Saskatchewan (Fig. 1)- 805 km north of Saskatoon, Saskatchewan, and 814 km northeast of Edmonton, Alberta. OwnershipGulf Minerals Canada Limited discovered the Rabbit Lake deposit in 1968. Mining operations began in 1975and were operated by Gulf until purchased by Eldorado Nuclear Limited in 1982. In 1988, Eldorado merged with Saskatchewan Mining Development Corporation (SMDC) to form Cameco-A Canadian Mining &. Energy Corporation. The new corporation is one of the world &apos;s largest uranium companies.Cameco&apos;s $1.5 billion in assets include the Rabbit Lake uranium mine (Cameco 100010); the Key Lake uranium mine (Cameco 66.67%; Uranerz Exploration and Mining Limited 33.33%); the Cluff Lake uranium mine (Cameco 20%; Amok Ltd. 80%); the Fuel Services Division at Blind River and Port Hope, Ontario (Cameco 100%); and a 100%); and a 48.75% interest in the Cigar Lake uranium deposit which is now at the test mining stage (Cogema Canada Ltd . 32.625% ; Idemitsu Uranium Exploration Canada Limited 12.875%; Corono Grande 3.75%; Korea Electric Power Corporation 2%). In addition, Cameco is involved in a number of base and precious metal explor ation projects."

Jan 1, 1989

By E. G. Parker

"Sherritt&apos;s zinc pressure leaching process converts zinc sulphide concentrates directly to zinc sulphate solutions and elemental sulphur. Thus, one pressure process step replaces both the roasting and leaching operations of the conventional roast-leach route. In addition, high single-pass extractions eliminate the need for residue treatments to recover unleached zinc. Because pressure leaching produces elemental sulphur, rather than sulphur dioxide, acid plants and smoke stacks are not required, and air pollution control and work-place hygiene are greatly improved. .In 1977, Cominco Ltd. and Sherritt Gordon Mines Limited jointly operated a three-tonne-per-day pilot plant to demonstrate pressure oxidative leaching of Sullivan zinc concentrate and the subsequent separation of elemental sulphur. The process consisted of regrinding the concentrate, continuous leaching at 150°C at elevated oxygen pressures in a four compartment autoclave and the subsequent recovery of elemental sulphur, either in the molten liquid form from a decantation autoclave or as a flotation concentrate. Of the zinc contained in the concentrate, 97% was extracted in 90 minutes, and 96% of the sulphur was converted to the elemental form.Following the successful pilot campaign, Cominco began building the world&apos;s first commercial zinc pressure leaching plant. This plant, which was in operation by late 1980, will eventually treat about 25% of Cominco&apos;s planned zinc capacity of270,000 tonnes per year.This paper describes the general process principles, the results obtained from the pilot plant and the integration of the process into Cominco&apos;s operations at Trail. The application of pressure leaching to a ""grass-roots"" plant is also discussed, and compared with conventional roast-leaching."

Jan 1, 1981

By B. Van den Bogaert, K. Binnemans, T. Van Gerven

Europium is one of the most critical rare-earth elements due to the limited supply of this element combined with a high demand for red lamp phosphors. Therefore, the recycling of europium from end-oflife lamp phosphors has become increasingly important. Photochemical reduction of europium(III) to europium(II) and subsequent removal from rare-earth mixtures by precipitation as EuSO4 is a very selective and efficient method to recover europium from binary europium/yttrium solutions. It is shown that full separation of europium and yttrium is feasible from laboratory prepared non-equimolar Eu/Y mixtures up to a ratio of 1/20, which reflect the composition of red lamp phosphors. Optimal conditions were determined at pH 4 with isopropanol as a radical scavenger, which is a less harmful and toxic compound than the commonly used formic acid scavenger. Europium removal efficiencies of more than 95% were achieved, with a purity of 98.5% of the EuSO4 precipitate. The irradiance of the used light source, expressed in mW/cm2, has a large impact on the illumination time needed to remove europium from the solution. It is observed that higher irradiance results in a shorter induction time, i.e. a period during which virtually no europium is removed, and a faster removal rate once the induction time has passed. The photochemical separation technique was applied to recover europium from leached industrial red lamp phosphor (YOX) powder, with a Eu/Y ratio of 1/30. Europium recovery of 50% was reached with a purity of 96%, proving the feasibility of this method for the recycling of europium from end-of-life lamp phosphors.

Jan 1, 2016