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By S. Kwon, J. W. Wilson

"In salt and potash mines, the time-dependent deformation mechanism should be clearly understood based on in situ measurements to predict the performance of a mining design. In this study, in situ deformation measurements from the Waste Isolation Pilot Plant (WIPP) and other salt and potash mines were used to determine the transition time from the primary to the secondary creep stage and to investigate the influence of adjacent excavations such as a nearby tunnel excavation, panel excavation and/or pillar extraction on rock deformation. IntroductionThe deformational behaviour of underground excavations in salt and potash mines is complex due to the time-dependency of the rocks. When the material properties are determined from laboratory tests, they should be carefully applied to in situ conditions, because in situ conditions are completely different from laboratory conditions. For instance, in situ deformation measurements show that the deformation rate decreases with time similar to those observed in the laboratory during the early stages. However, the rapid decrease of deformation rate does not come from the microscopic strain hardening effect observed in laboratory tests, but mainly from stress relief around the opening after its excavation (Baar, 1977). It is, therefore, recommended to undertake in situ measurements and use them to understand the deformation mechanism.Even though in situ measurements are widely accepted as important information for understanding the deformation mechanism of salt and potash (Barr, 1971; Kovari and Amstad, 1993), not many publications have focused on the fundamentals of data measurement, the application of the measured data, and the development of data analysis techniques. Recently, several new techniques for better understanding the deformation mechanism of rock salt have been developed that are based on in situ measurements. Kwon and Miller (1995) developed a new technique for describing the actual deformational behaviour of an underground excavation in rock salt. The migration of “zero strain boundary,” which represents a no movement boundary around an underground excavation, could be calculated by the technique developed by Kwon and Miller (1996). Kwon and Wilson (1997, 1998) applied neural network techniques to in situ deformation measurements to predict the deformational behaviour of the underground excavations at the Waste Isolation Pilot Plant (WIPP) located in the United States.In this study, in situ deformation measurementsfrom the WIPP site and other salt and potash mines in the United States were extensively analyzed to understand the deformation mechanism of the underground excavations in the rock mass."

Jan 1, 2002

By G. S. Cole

By 2025, the U.S. automotive industry will have to average 54.5 mpg (4.3l/100km) Corporate Average Fuel Economy (CAFÉ). While new/improved powertrain technology (turbocharging, electrification, diesels, transmissions and stop/start) will be critical, it is estimated that 25-40% of the new CAFÉ standards will require significant mass reduction, and lightweight structural materials will be required. This presentation examines vehicle mass reduction based on new developments in manufacturing automotive structures and components using light metals (aluminum and magnesium), conventional heavy metals (iron and steel), polymers, and carbon-fiber reinforced polymer composites. Components that used to be sand cast or pressure die cast provided minimal fatigue strength and ductility. But greater mass reduction uses more light metals in structural applications. They require eliminating porosity and inclusions to improve ductility and fatigue strength. Improved casting processing, with vacuum die casting, counter pressure and squeeze casting, and new forging and extrusion applications are being developed for this purpose. New grades of ultra-high strength steels can be made thinner, and save over 1/3 the mass vs conventional mild steels. But more complex and expensive processing, such as hot stamping and in-mold quenching, is required. Most engine block structures have migrated from grey cast iron to aluminum over the past 40 years. But compacted graphite cast iron has higher strength at high combustion temperatures and pressures so that high powered engines can be smaller and even lighter than aluminum. Assembling a range of lightweight materials into vehicle structures requires specialized assembly techniques, including sophisticated structural adhesives that can mitigate vehicles’ unique corrosion environment. The presentation will conclude with discussing lightweighting strategies of Asian, American and, European marques and the materials, component designs and assembly techniques used to achieve 2025 CAFÉ.

Jan 1, 2016

By Geology Staff, C. H. Stockwell

"The Flin Flon base metal mine, owned and operated by the Hudson Bay Mining and Smelting Company, is on the Manitoba-Saskatchewan interprovincial boundary at a point 400 miles north of the International boundary. The deposit was discovered in 1914 by Thomas Creighton and the Mosher and Dion brothers. Since production commenced in 1930, 25,000,000 tons of ore have been mined. On January 1st, 1946, reserves were estimated to be 26,000,000 tons, averaging 2.99 per cent copper, 4.i4 per cent zinc, and 0.089 oz. gold and 1.25 oz. silver per ton. In addition to the four metals named, others recovered from the ore include- cadmium, selenium, and tellurium. The mine workings extend to the 3,750-foot level, but little development work has yet been carried on below 3,250 feet.The known ore occurs in six lenticular to irregular bodies within a zone 500 feet wide. These bodies average 900 feet long, 70 feet wide, 1,500 feet in vertical depth, and 2,500 feet in length along the plunge. They were formed by replacement of the country rock and include ore of two types, solid sulphides and disseminated sulphides. Seventy per cent of the total known ore is of the solid sulphide type. This consists essentially of metallic sulphides- chiefly pyrite- with included remnants of the host rock, and additional quartz and carbonate. In places, the ore exhibits banding, inherited from pre-existing structures. The disseminated ore occurs usually on the footwall side, and along the bottom of the plunge, of the solid sulphide bodies."

Jan 1, 1954

By Guy Chevalier

The QCM Mount-Wright mine and concentrator complex produces about 14 M tonnes of iron concentrate annually. Approximately 9.5 M tonnes of this concentrate are used to produce iron ore pellets at four different silica grades: Three for blast furnace operations and one for direct reduction furnaces. The paper presents the scientific approach that led to the realization of two projects where the acquisition of new process equipment led to an improved pellet plant iron recovery, a better flexibility and to lower operating costs as well as to the production of fine iron ore concentrate from the Port-Cartier tailings pond. Typical 4.8 % SiO2 concentrate is processed to achieve required pellet silica content. This is obtained with the aid of hindered settlers or hydraulic classifiers, screens, whims and, lately, spirals. The increasing demand for low silica iron ore products resulted in a greater need for upgrading. The Pellet Plant upgrading capacity being limited, more and more iron units were lost. Base on test works results and economic evaluations, QCM engineers figured out a way to increase efficiently their upgrading plant capacity and go back in the pond gather what has been lost in recent years of operation.

May 1, 2007

By J. -F. Blais, M. -O. Simonnot, J. Mocellin, G. Mercier, J. -L. Morel

Large quantities of ferromanganese sludge are generated as waste material by blast furnace during the manufacturing of ferromanganese. These slags are very rich in manganese, zinc and lead (5 to 40 %). These residues have been deposited in a pond in periphery of the steel industry. Considering the market value of the metals, these brownfield sites can now be considered as secondary resources. We have developed a hydrometallurgical process for selectively leaching Zn, Mn and Pb in order to produce compounds of Mn and Zn pure enough to be economically recoverable and a residue rich in Pb. Batch laboratory experiments were carried out to determine appropriate leaching conditions to maximize zinc extraction (100 %) and manganese extraction (90.0 %) with sulfuric acid and to generate a residue containing 15 to 30% of lead. This Pb residue is recyclable by another process.

Jan 1, 2015

By I. L. Sills

Introduction So many minerals and mineral products are used in the glass industry that it would require an unduly long paper to deal adequately with all of them. Only those that go to make up the batch for the more common types of glass will be discussed here, and even with these only, the list is a lengthy one. It is true that for the body of the glass comparatively few materials are required-as silica sand, soda-ash, lime, and feldspar. The others are used mainly to colour or decolorize the glass, or to give it some other desired characteristic, such as high lustre, greater physical strength, or opalescence; but, although they may be present in very small quantities, they are just as in-dispensable to the glass industry as are the main constituents of the batch. Sand Sand is essentially quartz, the dioxide of silicon, Si02. Most glass contains from 71J to 75 per cent silica. Sand for use in the glass industry, or 'glass sand', is obtained both from deposits of unconsolidated material, commonly referred to as 'sand', and from solid rock-sandstone, quartz, or quartzite. For the manufacture of glass, the material must possess a high degree of purity, as noted below, so that, although sand is widespread in most parts of the world, and sandstone, quartz, and quartzite are not at all uncommon, it is only in certain places that suitable deposits are found. At the present time, most of the glass sand used in Canada is imported from France, Belgium, and the United States. The French material, from Fontainebleau, near Paris, is known the world over as a very high quality glass sand. That from Belgium is nearly as good and is lower is price.

Jan 1, 1934

By J. Cayouette, C. Bolduc, P. Blatter

"The LaRonde mill was commissioned in 1988 and began treating ore from the Penna shaft in 2000. The mill has been expanded to accommodate 7,500 t/day, but ramped down to 6,000 t/day since the deep extension began. The process recovers gold, silver, and base metals. In 2008, the Goldex plant began trucking gold-pyrite concentrate to a treatment plant feeding pulp to the LaRonde mill, increasing gold output by 40,000 oz. In 2009, the high-grade Lapa ore processing facilities were annexed to the LaRonde plant, increasing gold output by 120,000 oz. This paper outlines the metallurgical considerations related to the treatment of different ore types.RÉSUMÉ Le concentrateur de la mine LaRonde a été mis en service en 1988 et a commencé à traiter le minerai du puits Penna en 2000. La capacité du concentrateur a augmenté afin de permettre le traitement de 7 500 tonnes de minerai par jour, capacité qui est retombée à 6 000 tonnes par jour (tpj) depuis le début de l’extension en profondeur de la mine. Ce procédé permet de récupérer de l’or, de l’argent et des métaux communs. En 2008, l’usine de traitement Goldex a commencé à transporter par camion du concentré de pyrite et d’or vers une usine de traitement alimentant en pulpe le concentrateur de LaRonde, augmentant ainsi la production d’or de 40 000 onces. En 2009, les installations de traitement du minerai à haute teneur de Lapa ont été annexées à l’usine de traitement de LaRonde, augmentant la production d’or de 120 000 onces. Cet article passe en revue les considérations métallurgiques liées au traitement de différents types de minerai.INTRODUCTIONThe LaRonde metallurgical plant in the Abitibi region of Quebec, Canada, evolved into a mature milling site following expansions in 2000–2003, thanks to improved processes, manpower, and water treatment capabilities that better accommodate the complex constituents of the LaRonde ore. The ore requires a sequence of grinding, copper- lead and zinc flotation, and precious metals leaching, ending with a carbon-in-pulp (CIP) gold recovery. A portion (35%) of the tailings is sent back underground as paste backfill after being treated with the SO2-air cyanide destruction process. The tailings area has a dedicated cyanide destruction and metal precipitation area through which the used water passes before returning as recycled water. A biological water treatment plant was built in 2004 to address water toxicity in the final effluent. The water toxicity was the result of the high sulfide content of the LaRonde ore (from thiocyanate or stable cyanide species buildup) and the use of 90% recirculated water in the mill. The water treatment plant uses bacteria to transform thiocyanate into nitrates and precipitate phosphorus from the water before it is discharged into the environment."

Jan 1, 2017

By C. E. Dowker

"IntroductionMechanization underground at the Buffalo Ankerite mine in Deloro township, Porcupine district, had reached a high level by 1944, both in equipment available, and in the use of this equipment, for all stoping operations. Power feed leyners and the latest type of stopers for drilling, slushers for moving ore and fill, and tugger hoists for all servicing, did much to halt rising stope costs, and in some cases decreased them. On the other hand, little beyond the use of mucking machines and power feed leyners had been adopted in the effort to reduce level development costs, or to increase the advance per man-shift.Faced with ever increasing level development costs, caused by rising prices of equipment and supplies, coupled with increasing wage demands for less physical effort, it was realized that more mechanization of development work was essential. The objectives of such further mechanization were:(1) Decreased development costs(2) Increased footage per man-shift(3) Less physical effort by development crews, with greater take-home pay (4) A more satisfied and stable labour force"

Jan 1, 1950

By Descarreaux. Jean

"The Abitibi volcanic belt was sampled along a cross section extending from Matagami to a point east of Rouyn. A few samples were also collected in Louvicourt township, Quebec. The major elements were determined for 344 samples, and rock names were defined using normative minerals. The analytical data were studied by means of variation diagrams. The Abitibi volcanic belt is characterized by rocks belonging to both the tholeiitic and calc-alkaline magmatic series, but they show some differences as compared to some typical reference series, particularly those from Japan. Basalt is the predominant rock type and accounts for 44 per cent of the sampled outcrops. The volcanic rocks are relatively poor in K2O and TiO2. Regionally, the volcanogenic copper-zinc mineralization is associated with the calc-alkaline volcanic sequences. Locally, within such sequences, some types of abnormal deviations from the averages are recognized only in association with the copper-zinc mineralization. The anomalies are ascribed to hydrothermal alteration consisting of the introduction of MgO and removal of N a20; enrichment in K20 is also observed where zinc mineralization predominates. Examples of such anomalous zones show that, in places, this alteration phenomenon can be quite extensive. Petrochemical characteristics can be used as geochemical ore guides in exploration programs."

Jan 1, 1973

By H. Bouzahzah

Sulfidic tailings, subjected to atmospheric water and oxygen action, can generate acid mine drainage (AMD); which is the most important environmental problem facing the mining industry. AMD generating potential can be assessed by the static tests which consist of a screening method where the neutralization potential (NP) and the acid-generating potential (AP) of a given rock sample are determined. The AP and NP are determined separately in the different static test existing procedures which can be divided into two distinct classes: chemical and the mineralogical methods. For some chemical method, the AP is calculated on the basis of total sulfide sulfur content in the sample which may overestimate its AP if significant quantities of non-sulfide sulfur species are present (e.g. organic S in coals, some sulfate as gypsum, barite, etc.). However, the mineralogical method evaluates the AP by the sum of the individual sulfides participation on acid generation based on their concentration within the sample and can be more accurate than the chemical method. For AP calculation, the Paktunc (1999a) mineralogical static test takes into consideration all sulfide minerals occurring in the sample. However, it does not take into account the rates of acidity production of these sulfides submitted to weathering conditions. So, the present study focusses on the modification of Paktunc AP calculation by considering the acidity production rates of these minerals. To reach this objective, five base-metal sulfides (pyrite as reference, chalcopyrite, sphalerite, arsenopyrite, galena), diluted within quartz (25?75 wt.%) simulating mill tailings were subjected to a kinetic test to evaluate their AP. The results show that all the studied sulfides minerals generate acidity at different rates, so the Paktunc?s equation for AP calculation has been adapted accordingly.

Aug 1, 2013

By D. A. Wheeler, Rémi Tremblay

"INTRODUCTIONDuring the last few years, through Column Flotation Company of Canada ltd, the Centre de Recherches minérales has worked on the column flotation of coal, phosphate, feldspar, talc, graphite, copper, lead-zinc and diamond ores. The operating companies and prospective deposits were located in Canada and in other countries. Since these projects were financed by the concerned mining companies, all results remain confidential unless we obtain permission to publish. Three companies have graciously allowed us to use their information which I will describe in this text. These are the Polkowice copper mine in Poland, the North Coast Industries ltd graphite deposit and a talc company which preferred to remain anonymous. I will also describe our 2 inch column which was used for all tests. Data is also given on how to scale-up the 2 inch column to industrial size.Figure 1 presents a schematic of a flotation column. Feed, at a controlled rate and pulp density, enters at about 1/4 of the height of the column from the top. A controlled rate of air is bubbled into the bottom of column through a fine-holed sparger. The column volume between the feed point and the top of the sparger is called the recovery zone. Tailings, at a controlled rate, always slightly greater than the feed rate, discharges from the bottom of the column. This difference in feed and tailings flowrates is called the bias. The floated mineral is carried through the recovery zone on air bubbles which rise into the cleaning zone which is that column volume between the feed point and the overflow at the top. As the bubbles rise in this zone they are washed of gangue material by wash water which enters over the top of the froth layer. The froth layer is maintained at a given depth during flotation but this depth will depend on the froth cleanliness, for quite a bit of cleaning by wash water is accomplished in this layer."

Jan 1, 1988

By Q. Liu, P. Katsabanis, J. A. Meech

A thermohydrodynamic computer code has been used to simulate dust explosions. For sulphide dusts, the thermodynamic predictions are used to investigate the effect of dust concentration, mineral content and inert materials as well as the quantity of sulphur dioxide produced. It was found that the amount of oxygen available for the explosion is very important and that the dust concentration which gives maximum explosion pressures is obtained at zero or slightly negative oxygen balance values. The sulphide minerals were found to have the following explosibility sequence: pyrrhotite, pyrite, chalcopyrite, sphalerite, covellite, chalcocite and galena, which is in agreement with mine experience. The results show that theoretical calculations can be used to predict explosion pressures and toxic gases produced by a dust explosion and therefore they can assist in the design of protective measures .

May 11, 1988

By A. Motamedi

Indoor localization has gained importance as it has the potential to improve various processes related to the lifecycle management of facilities and to deliver personalized and location-based services. Radio Frequency Identification (RFID) based systems, on the other hand, have been widely used in different applications in construction and maintenance. This paper investigates the usage of RFID technology for indoor localization of RFID equipped movable assets during the operation phase of facilities. The location-related data on RFID tags attached to fixed assets are extracted from a Building Information Model (BIM) and can provide context-aware information inside the building which can improve Facilities Management (FM) processes. The paper proposes a new approach to use received signals from available reference tags in the building attached to fixed assets to locate movable assets. The approach uses signal pattern matching and clustering algorithms for localization. As a result, a user equipped with an RFID reader is able to estimate the location of target assets, without having access to any Real- Time Location System (RTLS) infrastructure. A case study is performed to demonstrate the feasibility of proposed methods.

Aug 1, 2013

By S. Averill, B. Schreiner, V. Sopuck

The La Ronge. Kisseynew, Glennie Lake and Flin Flon domains. the main focu for gold exploration in the southeast part of the Saskatchewan Shield, were subject to continental glacial ice advances from the northeast during the Quaternary. Based on forty-four auger hole along with surficial mapping, the general Quaternary stratigraphy in this area is observed to be composed of a lower till unit , an overlying stratified unit of glaciofluvial sand and gravel and/or a glaciolacustrine silt-clay unit. an upper till. and an upper tratified unit. The lower till is commonly found throughout the geological domains except where it has been eroded in glaciofluvial or fluvial channels. Glacial Lake Agassiz fo rmerly covered most of these prospective domains. The lacustrine deposits associated with the lake impede surficial geochemical surveys including soil. lake sediment. and biogeochemical surveys. The approximate extent of clay cover can be predicted from beach elevations. For instance. in the Waddy Lake area. clay i not known to occur above about 1,400 feet (425 m) elevation. Exploration techniques are hampered by clay in at least one third of the volcanic belt. Thi s influence is indicated by the fact that nearly all gold prospect found to date are located above 1,400 feet (425 m) while the area of clay cover is vi rtually unexplored. The upper till i related to a minor ice readvance. This till is the medium often sampled during soil surveys in the area . lts value as a geochemical ampling medium is dependent on the extent of erosional contact with bedrock highs on the lower till. Those areas which are relatively free of lacustrine and fluvial deposits are those where surface geochemical methods work best. In the Waddy Lake volcanic belt approximately 25-50% of the area may be suitable for surficial surveys. The area of the Star Lake prospect occurs above the 1,500 foot (460 m) elevation and was not covered by Lake Agas iz. The effectivene of till sampling as a surface sampling medium was tested in those areas above the clay level. Till orientat ion surveys were carried out at the Star Lake property and the Tower Lake prospect (Waddy Lake area) within the La Ronge Domain . Gold grain counts and analy es of heavy mineral concent rate from 7 kg surface ti ll samples were used to delineate dispersion trains down-ice from mineralization. In addition, the clay fraction and a 30 g (-80 mesh) subsample from the same till sample, were analyzed for gold . In the Star Lake area, ice direction is subparallel to the strike of several narrow northeast trending auriferous structures. arrow dispersion trains down-ice from known

Jan 1, 1986

By L. E. Fischer

The background for the 630-million-dollar-plus iron ore project at Kudremukh is outlined. The system and plants for mining, crushing, concentrating, transporting via a slurry pipeline, filtering and shiploading 7.5 million metric tons of iron ore per year are fully described. The mode of operation and the problems encountered in such a transfer of North American technology to developing countries are analyzed. Difficulties encountered during construction are discussed and the progress milestones made over a two-year period are enumerated.

Jan 1, 1979

By A. Warczok, T. A. Utigard

"Slags from smelting of copper concentrates contains from 1 to 15% of copper. Copper is present in the form of copper or copper matte inclusions of size from 2 to 1000 micro, and as dissolved cuprous oxide. Removal of the copper requires the slag reduction, primarily reduction of magnetite and co-reduction of cuprous oxide. Thus, the kinetics of the slag reduction play an important role in copper recovery. Instantaneously, at the contact of carbon and a slag the gaseous film is formed. The magnetite and cuprous oxide reduction is going through a gaseous film, separating the slag and carbon of a coke or electrodes. The thickness of a gaseous film grows to a critical value and gas bubbles, containing CO and CO2, are created and rise up in the slag. Results of measurements of kinetic of the slag reduction with graphite showed high value of activation energy, close to the value of activation energy of Boudouard reaction. Strong temperature dependence of the reaction rate points out the thermal instability of the reacting system. It was found that the slowest process in the reduction stages determines the loop of CO and CO2 transfer and magnetite diffusion to the slag/gas film boundary. Strongly endothermic Boudouard reaction seems to cause thermal instability on the reaction surface. So, heat transfer to the reaction surface is very important. Due to low thermal conductivity of a slag the convection dominates in the heat transfer. So, any slag stirring accelerates the rate of reduction and coalescence of metallic copper or copper matte inclusions."

Jan 1, 2015

By G. F. Liu, S. Owada

Platinum Group Metals (PGMs), Pt, Pd, Rh, have been widely used as a three-way catalyst to clean discharged gas from automobiles and therefore a considerable amount of the spent catalysts is generated annually. This paper proposes a novel concentration technology of PGMs by utilizing the double-deck structure of PGM bearing alumina-ceria and cordierite phases. The applied technologies are a combination of heating-quenching, selective grinding and screening for separating alumina-ceria phase from cordierite. Temperature change as a function of quenching time and the thermal stresses applied to both phases were simulated and calculated by FEM, and it was clarified the mechanism of micro-cracks generation at the phase boundary and micro-cracks in alumina-ceria phase, which indicated that separation of alumina-ceria phase from cordierite and selective breakage of alumina-ceria phase could be achieved in the subsequent selective grinding with an attritor. This process could concentrate 46 wt% of alumina-ceria phase into fine fractions with 86 % recovery efficiency. The remaining alumina-ceria phase can be further recovered by applying flotation and so on.

Jan 1, 2015

By H. W. Wevers

Fatigue failure and accompanying brittle failure occurs frequently in heavy mining equipment. This paper discusses how fracture mechanics can be applied as a tool for crack control and crack management. Information is provided to determine if particular components are prone to brittle failure. By using existing fracture mechanics formulae, an estimation of the critical crack size can then be made. It is explained that for a successful application of fracture mechanics, both the actual engineering stress in the component and the mechanical properties of the applied material must be known. The importance of toughness at low temperatures is quantitatively illustrated by calculating critical crack sizes at room temperature and at below-zero temperatures. Understanding the possibilities of fracture mechanics will also produce a climate in which the purchaser of equipment can more precisely analyze the relative quality of components with respect to crack tolerance and failure prevention. In this manner, communication between the user and manufacturer of equipment may also become more precise and effective, leading to improved design.

Jan 1, 1977

By Gordon Jackson

"There are two accomplishments of air and gas drilling: a new series of economic and mechanical challenges; and, acceptance as a standard drilling and completion tool.The new challenges are related to the concept of using a gaseous circulating medium in drilling for oil or gas. For purposes of discussion, a two part division has been made: the challenge of fluid invasion control and that of equipment and tools. Great strides have been made in the development of materials and techniques to combat formation fluid invasion. Chemicals and the ""mist drilling"" technique, now in use, have the versatility to cope with a wide range of downhole fluid entry conditions.Equipment and tools have been developed to meet the challenges of better, more economic drilling and completion possible with a gaseous circulating fluid. Economic and operational challenges remain.Acceptance of air and gas drilling as a normal operating tool was reached with difficulty. It is now established as a means of reducing costs in exploratory and develop-mental well drilling, exemplified in a recent study of 226 wells covering 419,407 feet of hole in the United States. Air reached the projected depth in 85 per cent of the operations, although formation water was encountered in 48.7 per cent of the holes. Slim hole bit performance and cost all compared for overall bit averages as part of analysis."

Jan 1, 1961

By B. C. Tripathy, S. K. Padhy, R. K. Paramguru, Pinak Patnaik

"Cobalt is regarded as technology enabling metal among the less abundant metals found in the earth crust. Electrodeposition of the metal from aqueous sulphate solutions is the preferred technology for its commercial production. Certain additives are added in the electrolytic bath during electrodeposition for the production of uniform, smooth and bright deposits of cobalt metal with higher current efficiencies and lower energy consumptions. A detailed investigation has been carried out to determine the effect of additive Sodium octyl sulphate (SOS) on the electrodeposition of cobalt. The results indicated that the additive apart from increasing the current efficiency enhanced the quality of cobalt electrodeposits. A maximum current efficiency of 98.4% was achieved at 10 mg/L SOS. The presence of SOS in the electrolytic bath did not result in any noticeable change in the crystal orientation of the cobalt electrodeposits except at higher concentrations (50 g/L) of the additive. Scanning electron micrographs indicate that smooth, compact and uniform deposits of cobalt were obtained at 10 mg/L of the additive beyond which there is detoriation in the quality of deposits. Polarisation of the cathode was seen in the presence of SOS. The effect of SOS on the electro kinetic parameters: Tafel slope (b), transfer coefficient (a) and exchange current density (I0) has also been investigated.INTRODUCTIONCobalt is recognised to be a strategic metal among the various base metals, owing to its numerous applications in various industries. Cobalt as a metal finds its use in the preparation of rechargeable batteries, as an alloying component in the manufacture of space craft and jet engines, as a drying agent for paint varnishes, ground coats for porcelain enamels and in the manufacture of the catalysts for the petroleum and chemical industries (Davis, 2000). Although there is a huge demand of the metal the supply of the metal is limited due to its scarcity in the earth crust. The metal comprises of only 0.02% of the earth’s crust for which the metal is recovered from various ores of nickel and copper as a byproduct (Hawkins, 1998). The present day techniques for cobalt production includes mostly hydrometallurgical methods which are preferred over the earlier used pryometallurgcial methods carried out for the metal production. Almost 70% of the world’s cobalt produced currently is from hydrometallurgical techniques in which electrodeposition of the metal from aqueous solutions is the final step for metal production (Verney, 1988). The most preferred route for electrodeposition of cobalt metal involves a sulphate medium (Das and Subbaiah, 1984; Lenthall and Bryson, 1997; Sharma et al., 2005)."

Jan 1, 2016