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By F J. Pearce

The Steel Company of Canada, utilizing the S-L process, has produced partially and highly reduced pellets for use in the blast furnace. Experimental blast furnace tests, using reduced pellet burdens, have been carried out. The changes in production rate, fuel rate and general performance of both the S-L and the blast furnace processes are indicated. Introduction T HE ore burdens for a blast furnace may be improved in two ways: chemically, by concentrating the ore to a high degree of purity; and physically, by agglomerating or closely sizing the ore particles. Today, many b1ast furnaces are charged with closely sized agglomerates, some of which contain upwards of 66 per cent iron. The further improvement of these burdens by chemical concentration may, in many instances, be uneconomic due to the large losses of iron that occur during processing. Assuming that it would be possible to reject all of the gangue minerals, the maximum level of concentration of iron in the hematitic ores would be only about 70 per cent.

Jan 1, 1964

By G. Hu, P. Chang

"As hydraulic fracturing is forbidden in some countries due to its accompanying environmental pollutions, microwave fracturing was proposed as a substitute technology to enhance coal seam permeability. Its mechanism includes: on the one hand, thermal stress caused by non-uniform microwave heating leads to fracture development in coal body, which increases coal seam permeability for gas; on the other hand, moisture within the coal body that hinders gas desorption and diffusion is removed during this process. To study the effect of moisture content on fracture development under microwave irradiation, high resolution photographs were taken before and after microwave treatment. These photographs were then binarized and skeletonized. Based on the processed photographs, the total area were calculated using ImageJ. The results showed that coal samples with 0% and 25% water saturation have more variation in fracture development as compared to that of samples with 50%, 75% and 100% water saturation. This study can be very useful in gas drainage and gas control in coal mines. INTRODUCTION Coalbed methane (CBM) is a clean energy source as well as a natural hazard to underground mining (Kurnia, Sasmito, & Mujumdar, 2014; Ranathunga, Perera, & Ranjith, 2014). One of the main goals of mine ventilation is diluting methane and removing underground contaminants (Xu, Huang, Nie, Chalmers, & Yang, 2017). Coalbed methane (CBM) has to be extracted prior and during underground mining to avoid methane outburst and explosion accidents. However, with the increase of mining depth, the coal permeability decreases significantly, which makes it hard to extract the methane (Huang, Xu, Hu, Kizil, & Chen, 2018). To enhance the coal seam permeability, many CBM recovery methods have been applied on-site, such as hydraulic fracturing and enhanced coalbed methane (ECBM). However, hydraulic fracturing is restricted due to environmental concerns and ECBM is only suitable for the coal seam with relative large permeability (Bustin, Bustin, Chikatamarla, Downey, & Mansoori, 2016; Huang, Xu, Chen, & Chen, 2018; Huang, Xu, Hu, et al., 2018)."

Jan 1, 2019

By J. Q. Chen

The elastic-plastic behavior and the fracture mechanisms of two 2198 Al-Cu-Li thin sheets are investigated. The first material (2 mm thick) is in a recrystallized state after cold rolling. The second material (6 mm thick) is hot rolled and has a fibrous grain structure. The two materials are studied in both T351 and T851 conditions. Tensile tests are carried out along different sheet directions using flat and notched specimens. Fracture resistance was characterized using Kahn tear specimens and M(T) panels. Macroscopic fracture surface of smooth tensile specimens depends not only on testing material but also on the loading direction. For Kahn tear specimens, fracture is initiated in a small flat triangle whereas slant fracture is observed during crack propagation. Fracture mechanisms were investigated using scanning electron microscopy (SEM) and X-ray 3D tomography.

Jan 1, 2011

By W. R. Bruce, G. W. Hodgson, K. A. Clark

"IntroductionANY PLANT processing mined Athabaska oil •sand for the recovery of oil produces, as a waste material, about one ton of sand for every barrel of oil recovered. A disposal problem of major proportions is thus indicated. For a 100,000-barrel per day plant, provision must be made for moving .about 4,000 tons of sand per hour on a continuous basis to a tailings dump at least several thousand feet removed from the plant site.Of the many known ways of conveying solids on .a large scale, the hydraulic pipeline transfer method is becoming increasingly important because of convenience and economy of operation. It has been in use for many years in mill operations at metalliferrous mines for the disposal of tailings and as such was a natural outgrowth of •hydraulic sluicing (3). Pipeline transportation of mill concentrates has been adopted recently ( 1), wherein high-density solids are moved several miles by hydraulic pipeline. The flotation power of the water suspending the solids may be increased 'by addition of magnetite for the handling of ore in pipelines (8). Low-density solids such as coal have received considerable study for low-cost pipe-lining (2) and a successful operation with coal has been carried out in England with indications of considerable savings over other methods of transportation (9). Dredge operations are based on pipeline transportation for the dredged sol-ids, and the scale of pipelining there .has involved pipe sizes as large as 32-inch (6). However, the tendency has been to regard the pumping of solids in water merely as a simple method of transportation and little consideration has been given in the published literature to study of the most economical modes of operating .a pipeline."

Jan 1, 1952

By G. Anger, J. Enser, H. Antrekowitsch, S. Koch

Homogeneous chemical composition and microstructure are always necessary, but not always attained in practice. As-cast aluminium alloys tend to have a segregation microstructure. Features of the cast structure, which affect subsequent processing or properties, can be altered by the homogenization. The main task of the Department of Nonferrous Metallurgy was to investigate the effect of homogenization treatment on precipitation hardening of aluminium alloys 6061 and 6082. The effect of the solution heat treatment (SHT) temperature on the mechanical properties was also analyzed. The homogenized and non-homogenized rolling slabs were produced according to the usual conditions and methods. The metallographic investigations were carried out on the as-cast samples, after homogenization, after the hot and the cold rolling mill, and after natural and artificial ageing. Then, Brinell hardness measurements and tensile tests were conducted on both alloys in order to examine the influence of the homogenization.

Jan 1, 2006

By H. Staton, XPS Consulting & Testwork Services, T. Deng, M. Kelvin

"Lundin Mining’s Eagle Operation, located in Marquette County, northern Michigan consists of a mine and concentrator that processes a Ni-Cu-(PGE) ore. Mine production began in 2014 and is expected to achieve production of approximately 23,000 tonnes of Ni and 20,000 tonnes of Cu per year. The ore is trucked to the Humboldt Mill, where both a Ni and Cu concentrate is produced.XPS Consulting & Testwork Services (XPS) has assisted the team at Eagle since 2013. Prior to start up, the ore was piloted at the XPS lab in Sudbury, Ontario to demonstrate the concentrator flowsheet and establish flotation operating strategy. XPS consulting metallurgists worked closely with the Eagle team during the commissioning of the plant providing troubleshooting, sampling, metal balancing expertise and support. Finally, a series of monthly composites over a 6 month period was submitted for mineralogical characterization to assess plant performance, identify opportunities for improvement and to provide a baseline for the future operation.Lundin’s investment to test the ores ahead of mining and to team with XPS’s experienced mineral processing engineers to help commission the plant has led to the plant achieving concentrator production targets shortly after startup. The commitment to training and implementation of best practices, and a culture where ongoing testing is the norm, puts the Eagle Operation on sound footing for future operation.INTRODUCTIONLundin’s Eagle Mine is a subsidiary of Lundin Mining located in the upper peninsula of Michigan. The mine itself is an underground operation and the ore is trucked from the Eagle mine site 2 hours to the Humboldt mill.The ore is an ultramafic hosted high grade Cu Ni deposit and exists as either massive or semi massive sulphides. The high resource grade of Cu (2.49%) and Ni (2.93%) make this a valuable ore source. (Owen & Meyer, 2013) A metallurgical team was put together by Lundin to ensure the mill was designed and commissioned to optimize metallurgy in the shortest time from this valuable deposit. The commissioning plan targeted commercial production by Q1 2015."

Jan 1, 2016

By J. B. Mawdsley

"AbstractThe uraninite-bearing deposits in the Charlebois Lake area of northeastern Saskatchewan are unusual and important concentrations of uranium. They were first discovered in 1949 and preliminary development work to the end of the 1951 field season indicates the probability that this will become •another uranium producing district. The deposits are in zones bordering granite masses. These zones are of migmatite (mixed rocks) composed of calcium-rich meta-sediments intruded and replaced by a fine-grained white pegmatite. Locally this pegmatite is replaced by an end fraction which is relatively rich in fine-grained disseminated uraninite; it is these occurrences that constitute the bodies of economic interest.The fine-grained white pegmatite contains plagioclase feldspar more lime-rich than that in the granites of which it is an end differentiate. This extra lime, evidently derived from the intruded sediments, would result in the raising of the temperature of crystallization of the pegmatite-forming magma, thus consolidating it rapidly near the granite contacts as a fine-grained pegmatite. The end liquor containing uranium was evidently locally concentrated in minor fracture zones in these pegmatites. Where no lime sediments were present. the coarse-grained alkaline pegmatites were formed. Their crystallization would not be accelerated and the uranium would tend not to be localized in the pegmatite but to migrate and consolidate at lower temperatures with the end products, possibly in some instances as pitchblende veins."

Jan 1, 1952

By D. C. McKechnie

To the examining engineer, the ever-recurring problem involving the valuation of ore in a prospect presents at different times highly divergent aspects- some entirely physical or mathematical, others essentially personal. The majority of the problems discussed in this paper are obvious to the engineer, and need little elaboration. By the prospector and the general public, however, a number of these questions are often and completely over-looked, or else approached in such a way as to produce final results which are, to say the least, misleading and at times decidedly erroneous. While the purpose of this paper is to deal with prospects or potential mines, many of the problems considered apply equally well to mines with developed ore reserves. As the usual showings on a prospect consist chiefly of a few open-cuts and a limited amount of underground development work, an estimation of the actual ore reserves is a question of minor import, and seldom enters appreciably into an estimation of the probable value of the particular property. The physical valuation of a prospect mainly involves the consideration of such subjects as the general geological features exposed, the strength and type of mineralization, the width and persistence of any associated veins, shear zones, fractures or contact zones, together with the possible grade, size, and continuity of any ore-bodies that may there occur.

Jan 1, 1930

By S. G. Shabestari

In the metal casting industry an improvement of component quality mainly depends on better control over the production parameters. Thus, thermal analysis cooling curve of the alloy is used for process control in aluminum casting industry. Cooling rates of the alloy during solidification process affect microstructure, grain size, eutectic silicon morphology, and dendrite arm spacing (DAS). In this research, effect of cooling rate on the microstructure and solidification parameters of 319 aluminum alloy that is a widely used alloy in automotive industry, has been investigated by means of thermal analysis. Seven different cooling rates have been obtained by using CO2-bonded silica sand molds with two different wall thicknesses, hot-work tool steel molds (H13) with and without coating, thin-wall steel molds with different coatings. In each case, cooling curve and first derivative cooling curve have been plotted by use of very accurate thermal analysis equipment. Effect of different cooling rates on solidification parameters e.g. Nucleation temperature (TN,a), nucleation undercooling (ATN,a), recalescence temperature (TR,a), solidification range (AT,s), and total solidification time (t 0 have been studied in the liquidus region. Microstructural evaluation has been carried out and DAS were measured in all solidification conditions. A numerical equation was proposed to predict cooling rates via measuring DAS in 319 aluminum alloy. Nucleation process and the effect of cooling rate have been interpreted by using thermal analysis cooling curves and microstructural study.

Jan 1, 2004

By J. R. CAMERON

Gypsum is mined in all Atlantic Provinces except Prince Edward Island. It is generally thought to have been derived from the hydration of anhydrite in areas of minimal drainage. Late Devonian downwarping and crustal oscillation east of the Appalachian fold belt allowed the Windsor Sea to advance and retreat in a depositional trough and deposit about 1,000 m of sediments in Mississippian time, much of which were evaporites. The best areas for further gypsum development are lowland basins such as the Cape Breton Lowlands, the Hillsborough area of New Brunswick and the St. George's Lowlands in Newfoundland, all of which are already sites of gypsum quarries. Nova Scotia's gypsum is mined from the Lower Windsor Group, which is divided into subzones 'A' and 'B'; 'B' provides most of the province's gypsum production. The Atlantic Provinces gypsum industry has markets from the St. Lawrence waterway to the mouth of the Mississippi River.

Jan 1, 1984

By A. L. Valdivieso

"The correlation obtained by plotting pH of maximum adsorption of dextrin versus the isoelectric point of involved metal hydroxides can be used to predict the depressing effect of dextrin on flotation in ""pure"" sulfide mineral systems. Sulfides are strongly depressed by dextrin whenever their surfaces are coated by the corresponding metal hydroxide. The efficiency of dextrin as a depressant is affected by the adsorption of the sulfhydryl collector. Hydrolyzable cations modify this relationship in flotation of sulfide ores. This type of deviation of the real-life systems from the predictions based on the behavior of the pure systems shows the possible ways that could be followed to further improve the obtained correlations. Advances in Mineral Processing Science and Technology Proceedings of the 48th Annual Conference of Metallurgists ofCIM Sudbury, Ontario, Canada Edited by"

Jan 1, 2009

By H. S. Fowler

The Consolidated Mining and Smelting Company has been in the business of mining and exploration since its incorporation in 1906. The Company has reports written as early as 1890. Consequently, its files contain a very large number of reports, and also of maps, of ail descriptions. REPORTS Before describing the filing of maps, a brie{ note on our general system of filing reports will perhaps clarify the discussion. Reports of a non-periodic nature, primarily those based upon examinations by field engineers, are separated from all other data and filed in what we know as the Mine Series System. Each property on which reports are written is given a serial number, known as the Mine Series Number. This serial number is assigned at the time the first report is filed and it remains permanently identified with the property, regardless of its state of activity. Our mine series numbers now total over 5,000. The serial number for a property may be found by referring to an alphabetical index of properties. MAPS We found it necessary to divide maps into two groups: (1) Maps of properties (2) Maps of areas

Jan 1, 1944

"In the first half of 1990, Cambior earned $1104 million, or $0.37 per share, on revenues of$66.4 million. The company's strong cash position, attained late in 1989 and in the beginning of1990 through the exercise of warrants, put working capital at $83.8 million as of June 30, 1990. Long-term debt was reduced by over $10 million during the weak gold market, leaving the company with a debt to equity ratio of only 0.03. Production for the six first months of 1990 was 107 720 oz. Au, an increaseof24% over the corresponding period in 1989.Financial Profile/Results and Corporate Financial StrategiesTotal revenue for the 1989 fiscal year was $116,883,000 compared to $109,848,000 for 1988. The 1989 results achieved despite a lower average gold price, resulted from a higher level of commercial gold production and a 115% increase in investment income over 1988. Investment income rose to $3,568,000 in 1989 due to higher levels of cash assets.Cambior's mine operating costs increased 19% to $68,561,000 in 1989 from $57,472,000 in 1988. This increase resulted from rising operating costs at the Doyon Mine ($250/oz to $274/oz) due to the shift from open pit to underground operations, as well as from the start -up of three new mines with relatively higher costs. These costs have reached a stable level that should be maintained for the next few years.In 1989, net exploration expenses were $6,838,000, down 31070 from 1988, partially due to the Canadian tax reforms introduced since 1987. Depreciation and depletion grew by $1,432,000 in 1989, reflecting a higher volume of commercial production from the Pierre Beauchemin, Lucien C. Beliveau and Chimo mines.Net earnings for 1989 amounted to $17,661,000 or $0.73 per share compared to $17,438,000 or $0.74 per share in 1988.Cambior has an exceptionally liquid and strong balance sheet. As at December 31, 1989, net working capital stood at $85.6 million, with a total assets base of $338.6 million. With a long-term debt (including gold loans) of $21.5 million and shareholders' equity of $277.2 million, Cambior has a debt to equity ratio of 8%. All but about $100,000 of long-term debt is in the form of gold loans.The total market value for Cambior's stock as at September 10, 1990, stands at $420million, based on recent stock market prices. Cambior's stock and warrants are traded on the Montreal and Toronto Stock Exchange."

Jan 1, 1990

By A. Manohar Rao

Underground mining in general and more so the coal mining is a hazardous venture as it is a struggle against nature and natural forces. The stability of roadways has a direct impact on production and productivity. The roadway stability can be strongly influenced by the direction of the drivage. The stress studies are useful to provide a frame work for understanding the influence of drivage direction on roadway conditions, and to illustrate how mapping techniques can enhance this understanding. The act of mining can concentrate and re-orient the original stresses. Whenever coal is removed, the overburden weight that it carried is transferred. Vertical stresses are similarly affected when the roof is deformed or failed. The Singareni Collieries Company Ltd., a joint Public sector undertaking of the Government of Andhra Pradesh and India is conducting coalmining operations in the Godavari Valley Coalfield and is catering to the needs of a large part of South India. With the technology update, it is looking for safe mining and to achieve higher production. As a part of this, an attempt is made to understand the stress conditions prevailing on the mine blocks by different ways and means in terms of geology, structure and tectonics of the Godavari Valley coalfield, satellite imagery studies, cleat pattern, stress measurement studies conducted in different mine blocks, and stress mapping technique.

Aug 1, 2013

By Hani S. Mitri

Overhand cut-and-fill mining of narrow vein orebodies inevitably leads to the creation of horizontal pillars. As the thickness of the overlying crown pillar diminishes, stresses build up in the pillar. More often than not, this situation causes an increased level of seismicity and possible pillar burst. One well-known strategy to reduce the hazard of crown and sill pillar burst in cut-and-fill vein mining is that of destress blasting. The paper first reviews the methods used for the monitoring and assessment of potential pillar burst in narrow vein cut-and-fill mining. The influence of horizontal stress, mine depth and pillar thickness on stress build-up in the crown pillar is examined through a characteristic narrow vein numerical model. The paper then presents, with reference to three mine case studies, the benefits of destress blasting and the factors affecting its success as a ground control technique.

Oct 1, 2001

By Hans Lundberg

An electric survey from a 'plane flown over the ground is much faster and cheaper than an electric survey carried out on the ground. The results are obtained as continuous recordings that are resolvable into both a depth expression and a conductivity effect, so that the indications are easier to evaluate, as well as to correlate from one flown line to the other. The prospecting technique adopted in our electric airborne surveys may be brie fly described as follows: A loop of many turns of insulated copper cable is fastened around the fuselage of the 'plane and connected to a generator supplying a few ampere alternating current, usually of a frequency less than 1,000 cycles per second. Just as the current in the primary coil of a common transformer will induce current in the secondary coil when shorted, the alternating magnetic field from this primary current now induces alternating current in electric conductors that happen to be located in the vicinity of the path over which the 'plane is flown. This induced secondary current in each conductive section of the ground causes, in turn, an alternating magnetic field, secondary field, which disturbs or dampens the normal alternating magnetic field from the primary loop flown by the 'plane. These secondary fields are then picked up and recorded by the help of detecting solenoids, amplifiers, and recorders carried in the 'plane. By closer study of such a secondary field it is possible to localize the secondary current causing it and, thereby, the conducting body that contains the secondary current. In the 'plane are continuously recorded, besides the amplitude or intensity of the field, also the phase, which is a measure of how much the recorded secondary field is out of step with the primary field.

Jan 1, 1950

By M. Drozd, M. Somppi, Z. F. Yamak

"Activated carbon is used to recover gold in solution from various gold circuit designs including carbon-in-pulp (CIP), carbon-in-column (CIC), and carbon-in-leach (CIL) processes; however, the characteristics and durability of the activated carbon can vary. Handling this medium poses challenges when fine carbon losses occur in the CIP, CIC, and CIL circuit discharge. Additionally, adsorbed gold on carbon fines can be lost to the discharge. The studies in this paper aim to standardize laboratory methods for testing activated carbon qualities specific to the gold industry. The investigation focused on size distribution, platelet content, wet attrition resistance, gold kinetics, and gold loading. The results demonstrate that a 96 h attrition test and a gold loading test form a basis for ranking carbon samples based on expected economic performance of the plant. ¦ KEYWORDS Activated carbon, Carbon attrition, Carbon ball-pan hardness, Carbon evaluation, Carbon fines loss, Carbon turnover RÉSUMÉ Le charbon actif sert à récupérer l’or en solution dans diverses conceptions de circuits de broyage d’or, notamment les procédés de charbon en pulpe (CIP, de l’anglais carbon-in-pulp), de charbon en colonnes (CIC, de l’anglais carbon-in-column) et de lixiviation au carbone, ou charbon au lixiviat (CIL, de l’anglais carbon-in-leach). Toutefois, les caractéristiques et la durabilité du charbon actif varient. La manipulation de ce milieu pose des problèmes dès lors que se produisent des pertes de carbone à grain fin dans la décharge des circuits CIP, CIC et CIL. Par ailleurs, l’or adsorbé sur les fines de charbon peut se perdre durant la décharge. Les études réalisées dans le cadre de cet article visent à normaliser les méthodes de laboratoire pour tester les qualités du charbon actif spécifiques au secteur de l’exploitation aurifère. L’étude portait sur la composition granulométrique, la teneur des plaquettes, la résistance au frottement humide, la cinétique de l’or et l’adsorption de l’or, à savoir la capacité du charbon actif à adsorber l’or sur une période spécifique. Les résultats ont montré qu’un test de frottement de 96 heures et un test d’adsorption de l’or constituaient le fondement d’un classement des échantillons de carbone du point de vue économique en vue de trouver l’échantillon générant le meilleur rendement des usines. ¦ MOTS CLÉS charbon actif, dureté de la batée des billes de carbone, évaluation du carbone, perte de fines de charbon, renouvellement du carbone, résistance au carbone INTRODUCTION The use of activated carbon for gold extraction is among the most common processes in modern gold-milling plants. Although gold losses are inevitable in the milling process, operators often focus on reducing gold loss to tailings. One focus area that is important in gold recovery is optimizing the use of activated carbon and examining potential changes to realize improved economics for carbon-in-pulp (CIP), carbon-in-column (CIC), and carbon-in-leach (CIL) processes. Granular activated carbon (Figure 1) is widely used for gold extraction from slurries containing gold-cyanide complexes. This activated carbon—produced from charred coconut shells—is well suited because of its adsorption kinetics, gold-loading capacity, attrition resistance, and ability to be reactivated. The extraction process using activated carbon technology involves adsorbing gold from an aqueous leachate; the gold is dissolved using a cyanide salt and consequently a dicyanoaurate(I) ion (Au(CN)2–) is formed, as noted in equation 1."

Jan 1, 2019

By R. B. Nourse, R. Hundermark, B. Masters, H. Joubert

The new 30 MVA slag cleaning furnace at Waterval Smelter, Rustenburg Platinum, South Africa, has been in operation since 10 March 2003. The furnace design and operation face a number of challenges including a wide variety of feed materials and resulting bath conditions. Furnace feed varies in combinations of granulated Waterval Ausmelt Converter Slag (WACS), hot fed Peirce-Smith converter slag, concentrate and reverts. Coke is added as reductant. The resulting slag composition varies considerably and regularly. For the case feeding WACS an almost pure fayalitic slag (60%+ FeO, 30%+ SiO2) with a very low viscosity results. Due to the widely varying slag conditions, including a superheated fayalitic slag with high fluidity, a robust sidewall design is required adjacent to the slag bath. For this reason the furnace sidewall is equipped with Pyromet's MAXICOOL® high intensity copper cooling system. The design and installation of the copper coolers as well as tap holes are discussed. To cope with the variation in bath conditions and high slag superheat (350°C when tapped at 1650°C), the copper coolers are capable of removing peak sidewall heat fluxes above 500 kW/m2. Feedback is included on the performance of the Pyromet MAXICOO® copper cooling system for the first two years of operation. The paper further includes an overview on the design and performance of the tap holes, furnace shell, furnace roof and copper slag spouts.

Jan 1, 2005

By M. Uszko

The climatic area in which Poland is located requires heating the ventilation air at intake shafts during the winter season. Air heating of the intake shaft should ensure safe operation of hoisting devices; while at the same time it also affects the conditions of the mine environment. The paper presents the issues of shaft heating in coal mines in terms of the mining law, the effect on the conditions of the mine environment and heating technology solutions used in the mines of Kompania Weglowa S.A. (KWSA).

Aug 1, 2013

By Ian Ewart, Trevor Bergfeldt, Gourab Satapathy, Ajay Patel

"Conventional electrowinning (EW) of nickel from sulfate electrolytes is complicated by several factors including the requirement for a diaphragm cell to separate the anolyte and catholyte and the need to minimize nickel mist emissions. Developed and commercialized by emewCorporation, this novel process electrowins high purity nickel cathode (99.5%) from copper refinery bleed streams using the proprietary emew vortex EW technology. The emew nickel process incorporates high flow rate in an enclosed cylindrical EW cell operating at high current densities that overcomes the challenges of conventional nickel EW and completely eliminates the risk of nickel mist emissions. The tubular cathodes are easily harvested and mitigate the effect of plating stresses inherent in nickel EW. The present paper describes the emew nickel process and its most recent application to copper refinery bleed streams at full-scale.INTRODUCTION To meet the stringent demand of customers, nickel producers are giving prime importance to production of high purity nickel cathodes. The major challenge for refineries is to improve cathode quality and appearance despite fluctuating electrolyte impurity levels. The basis of achieving good quality cathode includes the control of electrolyte impurities and consistency of specific process conditions. The commercial operation of emew nickel technology has been successfully implemented and has demonstrated the ability to produce high quality nickel cathode from refinery bleeds. This paper emphasizes the importance of upstream impurity removal to achieve the required nickel emew feed composition by evaluating the benefits of using selective precipitation as a purification scheme with the aim of improving the overall nickel recovery while ensuring suitable nickel concentration in the advanced electrolyte is achieved. Nickel electrowinning is similar to other electrowinning processes that employ insoluble metal anodes & cathodes. It requires the passage of direct current between two electrodes that are immersed in a conductive, aqueous solution of nickel salts. For the recovery of nickel from solution, the most common methods are electrowinning and hydrogen reduction. Electrowinning usually occurs from sulfate, chloride or mixed sulfate/chloride electrolytes. In sulfate electrolytes, nickel electrowinning cells are normally designed to achieve specific criteria as outlined below (Robinson & Tuppa, 2002):"

Jan 1, 2017