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By P. R. A. Andrews

"Areas of bubble contact were delineated for cassiterite in the presence of chloride, fluoride, sulphate, phosphate, oxalate and citrate ions using dodecylamine hydrochloride collector. The limits of pH, and the minimum collector concentration were established using the bubble pick-up technique.Bubble contact did not occur below the p.z.c. (point of zero charge), estimated to be 4.7, in the presence of chloride ion, and fluoride ion showed only a weak response in the same pH range. These anions are considered to act as indifferent electrolytes. Activation at pH values below the p.z.c. was obtained with sulphate, phosphate, oxalate and citrate ions; the greatest response was by oxalate and phosphate ions extending pick-up to between pH 2.0 and 2.5.Activation appeared to be strongest when anionic protonated species were in maximum concentration. Strong activation also corresponded to the formation of very stable metal ion species, thought to be formed on the surface of cassiterite, between exposed stannic ions and modifying anions; dodecylammonium ions being absorbed on the surface so modified."

Jan 1, 1991

By J. McCreedy

This paper reviews new methods of exploration for metals and new techniques of mining the deposits and extracting the metals from their ores. Examples of mining innovations are taken from Inco's Thompson Operation. The importance of presenting a favorable image of the industry to college students and young people deciding on a career is stressed.

Jan 1, 1971

By D. Mills, W. H. S. Lawson

"The need to make repairs is seldom a major consideration in the design, fabrication and installation of major components of electrical generation plants. Repair welding, however, is a fact of life in the electrical generation industry, for restoration of degradation in service, from cavitation of hydraulic turbine runners, to corrosion and fatigue damage in pressure vessels. In making weld repairs to carbon and low-alloy steels, the largest source of trouble is hydrogen embrittlement and related post-weld cracking. Various strategies have been developed to control problems from this source, including post-weld heat treatment, the use of nickel-base alloy filler metals and the temper bead welding technique. Each of these basic strategies is being applied as circumstances require; each strategy must, however, be implemented in a manner that reconciles weldment structure and hardness, degree of restraint and service environment with the consequences of unsatisfactory performance of the repaired component.IntroductionMajor working components of electric generating plants are specified and installed on the basis that, wherever technically and economically feasible, they will retain functional capacity without major repairs for the twenty-five-plus years of normal plant lifetime. Nevertheless, repairs are often required, and welding is usually an essential feature of the work. Remedial welding may be performed to correct design or fabrication errors which become evident only at the time of component installation. The most common causes of requirements for repair involve corrosion, fatigue or related processes which prove more aggressive than expected during service. Increasingly, our planning for future repair requirements is related to continual improvements which are occurring in nondestructive evaluation technology. As components are periodically reinspected during their service life, fabrication induced defects may be revealed for the first time quite late in the life of the component. When this occurs, repair must be considered wherever inaccessibility of a flaw makes it impossible to prove its inactivity. Finally, there are certain components, for instance in hydraulic turbines, which cannot be economically made or used without the expectation of service induced wear. Here, periodic maintenance welding must be regarded as a normal event."

Jan 1, 1981

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."

Jan 1, 2017

By A. A. Burgoyne

"The McDame chrysotile asbestos deposit located near Cassiar in northern British Columbia isfound at depth and on trend to the southeast of the currently mined open-pit Cassiar asbestos deposit. The ultramafic rock hosting the McDame is serpentinized peridotite of the Upper Paleozoic Sylvester Group contained in an ophiolitic sequence preserved within a lower thrust sheet of the Sylvester Allochthon. The Sylvester stratigraphic package is a series of thrust slices composed of argillite, tuff and volcanic flows, diorite and serpentinite. Contacts between units are often fault-controlled.The McDame asbestos-bearing ultramafite is considered to represent a separate interleaved fault-bounded slice of rock distinct from the Cassiar asbestos deposit.Asbestos mineralization of the McDame deposit was discovered in /978. Exploration during /980 and /98/ focused on extensive underground drilling of the deposit and in /983 on geological mapping, airborne and ground magnetic surveys. In /984 a 622.5 m borehole was drilled with a 242 m intersection of McDame ultramafite of which the lower 15/ metres contain potentially economic chrysotile asbestos. The McDame deposit averages 90 m thick, trends north-south, dips easterly and plunges southeasterly. The deposit is estimated to contain geological reserves in the order of 62 million tonnes containing asbestos fibre similar in value to the Cassiar deposit.The McDame is considered a major world-class asbestos deposit. A decision to develop and mine the deposit will require further substantial underground exploration and evaluation. A + 1200 m exploration adit driven to the hanging wall of the deposit was undertaken in 1985 in anticipation of bulk sampling and diamond drilling in 1986."

Jan 1, 1986

By L. Furtenbach, T. Möller

"Grinding mills are the heart of the mineral processing plant, and are production-critical machines which are required to achieve high availability. Liner wear life and a liner design that promotes ease of installation are important variables to achieve a high level of mill availability. Increased mill size results in more mill internal surface to protect, and more liner components to install and remove. This drives designers toward an increase in liner size to minimize the number of components to be installed by the liner handler. The liner attachment method can also have a large impact on mill availability as well as safety during installation.This paper outlines the experience from the development, installation and follow-up of liners installed in two 38' x 45' AG Mills at Boliden Aitik in Sweden. A new Poly-Met shell liner concept has been developed to minimize the number of liner components. The new Poly-Met shell liner components are made much larger than conventional Poly-Met or steel liners. This reduces the number of components to be installed/removed by the liner handler and helps to minimize installation time and consequently down- time. A new attachment system has also been developed to eliminate the need for the installation crew to be in the “drop-zone” of the shell liners while installing the liner bolts.One interesting aspect of this project was the requirement to predict liner life for these new large format AG mills. The existing 22' diameter mills at Aitik provided a base-line reference for this purpose, and DEM studies were used in the project development stage to predict the wear life of shell liners for the new 38' diameter AG mills. The results from this study are included."

Jan 1, 2012

By Roland Froidevaux

"The main object of ore reserve classification is to assess the reliability of an ore reserve estimate. Because traditional classification schemes fail to provide a means of calculating this reliability, the terms 'proven "" 'probable' and 'possible ' ore were introduced as an attempt to qualify it.Geostatistics, on its part, allows the quantification of the precision of any ore estimate and thus appears as an appropriate tool for ore reserve classification.However, the problem of fixing quantitative boundaries for ore classes remains. In order to be meaningful, ore class limits based on the degree of reliability should be customized to the commodity, and the type and size of the deposit. In addition, the precision of an ore estimate will be affected by the cut-off grade and the size of selective mining units.IntroductionPrimarily, ore reserve classification should be seen as a communication tool between the geologist and the mining engineer on one hand and the management and policy maker on the other. By classifying ore reserves, the geologist tries to answer the very fundamental question: ""What quantity of metal is there in the ground and how sure am I that it really exists?""The difficult y of quantifying the degree of reliability of reserves has led to the creation of a large suite of terms and definitions, with almost every mining company having its own set of definition standards. As lower-grade deposits are brought into production, the margin of tolerable error in estimates of the grade and tonnage is becoming much narrower. Consequently, the need for unequivocal definition of the reliability of ore reserves is increasingly acute. Most of the generally accepted systems of classification, however, describe the reliability of reserves in qualitative, rather than quantitative, terms."

Jan 1, 1982

By Mark W. Bartlett

Program Objectives ??Identify and implement a tool for haul truck drivers that: -Reduces or eliminates fatigue-related injuries and fatalities -Reduces accidents and equipment damage ??Following evaluation period, apply tool where most effective Why do We Need a Fatigue Monitoring Tool? ??Everyone has probably fallen asleep while driving ??Driver fatigue is a major source of property damage and serious haul truck serious incidents ??To protect ourselves from the other ?tired?driver ??To know when to ask for relief ??To know when we are seriously distracted from driving ??To measure improvements in sleep incidents based on shift changes and intervention ??To help prevent incidents like the following:

May 1, 2011

By D. E. Barnett

"Paramount to sound aggregate resource management is an awareness of what resources exist. For the past six years, New Brunswick has been conducting granular aggregate resource inventories in and around urban centres as a means of documenting, both qualitatively and quantitatively, these resources.These aggregate studies require extensive ground truthing due to the often small nature of the surficial feature s as well as extensive foliage. Approximately 35% of the province's land mass has been mapped at a 1:50,000 scale as part of this on-going program. Reports are published annually and include data on size analysis, lithology soundness, abrasion and absorption.Aggregate deposits in New Brunswick frequently reflect the local bedrock lithology and, whereas much of New Brunswick is underlain by soft, friable sandstone of Pennsylvanian age, it is necessary to transport aggregate for higher-specification use considerable distances. Alternatively, the construction industry must turn to crushed stone as a source of asphaltic or concrete aggregate.Over 40% of New Brunswick's land mass is owned by the Crown, and aggregate resources are managed under the Quarriable Substances Act. Under this legislation, permit applications are reviewed by a Land Management Advisory Committee which consists of representatives from the various government departments involved.IntroductionSurficial materials either directly or indirectly form the basis of much of our economic activity, whether it is the field of agriculture, forestry, manufacturing, construction or other. Although sand and gravel have been produced and used since the day s of early settlement, the economic significance attached to such materials has only recently been recognized by both government and the general public."

Jan 1, 1982

By T. Lux, H. -J. Krassnig, I. Filzwieser, E. Hecker, R. Degel, A. Filzwieser

Non-ferrous metals find their applications in smartphones, tablets and computers. These materials with their particular properties are the basis of our modern life. SMS group is well prepared for this huge market and for growing future challenges. A large contribution here is the new joint venture PolyMet Solutions that was founded by SMS group and Mettop, an Austrian engineering company, with the objective to develop new technical solutions for the primary copper production lines as well as for non-ferrous metals starting with the primary smelting of concentrate and ending with the electrolysis. PolyMet Solutions provides the process know-how whereas SMS group supplies the plants and equipment and Mettop the key components. SMS group and Mettop also cooperate in the field of tankhouse technology. Together with Montanwerke Brixlegg AG, Mettop has developed together with a parallel flow technology (METTOP-BRX Technology), allowing a current efficiency of above 98 % at a current density of 420 A/m², which is a milestone in copper electrolysis. For the secondary copper production route, SMS group and PolyMet Solutions developed an innovative refining furnace (PolyRefine) for the smelting and refining of copper scrap. The refined copper is directly charged to the Contirod line to produce copper rods and wires. The innovative cooling solutions of SMS and PolyMet Solutions come into play where furnaces have to stand the highest loads and stresses, for instance in areas of very high temperatures or temperature fluctuations, aggressive exhaust gases and slags, or at critical spots such as taphole areas. Custom-tailored cooling systems for furnace vessels make sure varying loads are compensated in a targeted and effective manner. The solutions include air cooling, spray cooling, cooling technologies with integrated copper elements such as CFM (Composite Furnace Modular) cooling systems, plate and finger coolers. The major innovation in the field of furnace cooling is the ILTEC (Ionic Liquid Cooling) Technology which paves the way for increased plant safety. This revolutionary, patented cooling technology is jointly marketed by Mettop and SMS group. It permits water-free cooling to be implemented and thus makes operation safe wherever it is applied. INTRODUCTION Non-ferrous metals or NF metals are changing the world. There is no modern industrial sector that can do without these valuable metals. Non-ferrous metals find their applications in smartphones, tablets and computers. These materials with their particular properties are the basis of our modern life. The importance of the non-ferrous metals market is reflected by two figures. In 2018, the production of non-ferrous metals was worth more than 237 billion Euros. This contrasts with 255 billion Euros of the value of iron and ferro- alloy production in the same year (International Organizing Comittee for the World Mining Congresses, 2018). Hence, the NF metal industry is almost as important as the iron and steel industry. SMS group is well prepared for this huge market and for growing future challenges. A large contribution here is the new joint venture PolyMet Solutions that was founded by SMS group and Mettop, an Austrian engineering company, with the objective to develop new technical solutions and to enhance customer value. The prices of nearly all metals have come under pressure during the past few years. Therefore, competitive technologies are regarded a crucial factor to achieve success in this critical market situation respectively to stabilize the market position.

Jan 1, 2019

By E. Busse, J. E. Burgener, J. G. Eacott, M. C. Robinson, P. E. Burgener

"This paper presents a preliminary assessment of the technical and economic feasibility of a caustic leach - electrowinning process for the recovery of zinc and lead from electric arc furnace baghouse dust at a mini-steelplant. Recent studies and literature are referenced briefly as they pertain to the formation and characterization of dust, toxicity considerations and alternative dust treatment and disposal options.Laboratory testwork results, published data, pilot plant experience and anticipated influences resulting from recycling residues are used for the purpose of developing a conceptual design for a caustic leach - electrowinning plant to treat 15,000 tonnes/year of dust at a one million tonnes /year capacity steelplant in Canada.Target economic studies, comprising preliminary estimates of capital and operating costs, revenues and rate of return are presented. Economic and commercial considerations concerning the relative merits of dust treatment at a centralized facility compared with an on-site plant are discussed.IntroductionThe treatment or disposal of mini-steelplant electric arc furnace (EAF) baghouse dust has been given increasing attention in recent years for two principal reasons. Firstly, the dust is now classed as a hazardous waste material under V.S. EPA regulations which prohibit its disposal in dumps other than controlled landfill sites. Secondly, the dust contains certain metal values, notably zinc and lead, which may be economically recoverable, depending on the costs associated with disposal resulting from enforcement of the EPA regulations. Other metallurgical dusts and waste materials, from both ferrous and non-ferrous operations, may require the same considerations as EAF baghouse dust.Several studies have been carried out to examine various aspects of dust treatment but few commercial plants are in operation. Technology employed uses pyrometallurgical techniques. Commercial-scale hydrometallurgical plants are not known to exist although small-scale plants are frequently more economically attractive than their pyrometallurgical counterparts which generally require economies of scale to be viable.The concentration of mini-steelplants in northeast V.S.A. and southeast Canada merits study to determine whether or not dust treatment for metals recovery is a commercially feasible alternative to disposal.This paper examines the technical and economic feasibility of a caustic leach - electrowinning process for the recovery of zinc and lead from EAF baghouse dust at an on-site ministeel plant processing carbon steel scrap and discusses economic and commercial considerations pertaining to dust treatment at a larger, centralized facility."

Jan 1, 1984

By Pierre Choquet

"The whole work carried out both in situ and in laboratory by a research group of the West German collieries is presented. This work has led to a design method of steel arch supports for gate roadways that gives full satisfaction in this particular coalfield. The method accounts for mining depth, the mining system (advancing or retreating), thickness of the coal seam and other parameters.Full statistics are then given on gate roadway supports of the ECCS (European Community for Coal and Steel) coalfields. They were collected by the author in order to show that the West German method can be applied to other coalfields as the long wall systems which are generally being used are very similar. Design calculations are conducted for each coalfield's case. They show that the method would have been able to predict in most cases the support actually used.Utilization of the design method is recommended to the Cape Breton Development Corporation 's mine operators because mining conditions, even though different from European ones, present a number of similarities which make it possible to apply the design method to their particular case.This procedure might be profitable in mines facing support problems in their levels and for any planning of future projects"

Jan 1, 1986

By Alexandre Desbarats, Michel David

"All optimum pit design studies start from the geological are reserves inventory, the estimated grades of all blocks of potential are within the interpreted limits of the deposit. The actual optimization procedure is then carried out on block valuations based on these estimated grades. Thus, the relevance of any pit design can be seen to depend directly on the ore reserve estimation . To insure a proper pit design, a first step would be to use a geostatistical reserve estimation technique such as kriging, however, this is not enough. A frequently neglected fact is that the blocks of ore estimated during the planning stage of the mine are usually considerably larger than those on which the ore-waste selection will be made at the time of mining. Experience in the exploitation of large low-grade deposits has shown that large blocks, estimated to be are, when mined selectively in smaller blocks, often yield significant amounts of waste material. This phenomenon, known as internal waste, is a function of the variability of the grades, the size of mining unit and the amount of sampling information on which ore-waste decisions are made.In this study, it was proposed to consider the effect of internal waste caused by selective mining, on. pit design, using geostatistical methods to predict the tonnage and grade of recoverable reserves within large blocks.Optimum pits obtained using a block valuation formula taking into account the recoverable reserves within large blocks were compared with optimum pits obtained using a conventional block valuation formula. It was found that the optimum pits obtained by the proposed method had the highest total valuations and thus were, in fact, ""more optimum”. These pits were characterized by greater are tonnages at a lower average grade, the additional ore more than compensating for the drop in grade. It was also found that the consideration of internal waste in pit design could considerably alter pit limits in marginal areas of the deposit.It was concluded that selective mining had a significant, potentially critical, impact on the design of optimum pits especially in the case of large low-grade deposits."

Jan 1, 1984

By J. B. Heslop, D. S. Bubar

"The Gondor Zn-Ag-Pb-Cu deposit is a stratabound massive sulphide lens occurring within Archean volcaniclastic rocks of the Yellowknife Supergroup. The deposit is located in the west-central portion of the Slave Structural Province, approximately 350 km north of Yellowknife.Initial diamond drilling at Gondor has outlined a steeply dipping, L-shaped, folded, massive sulphide body, which may be traced over a strike length of approximately 800 m, and to a depth of 350 m. True widths of up to 40 m have been intersected in the thickest part of the deposit. Preliminary estimates suggest that the deposit contains a minimum of 7.5 million tonnes grading 6% Zn, 50 g/tonne Ag and less than I% combined Cu and Pb. In addition, significant gold, grading up to 2.8 g/tonne, occurs in some parts of the deposit. The mineralization is open both down-dip and along strike.The Gondor deposit lies conformably within a predominantly east-west striking, north-facing sequence of felsic to intermediate volcaniclastic rocks. Coarse fragmental rocks are abundant in the hanging wall, whereas ash and lapilli-tuffs predominate in the footwall. The main structural feature in the area is a large-scale, steeply northeast-plunging, Z-shaped fold. The sulphide mineralization lies within the synformal portion of this fold, with the thickest part of the deposit coinciding with its hinge zone. Several episodes of faulting have also affected the local stratigraphy.The wallrocks of the Gondor deposit were hydrothermally altered prior to the onset of medium-grade regional metamorphism. A halo of altered rocks surrounds the massive sulphide lens, with no apparent difference in the degree of alteration between the hanging wall and footwall strata. The alteration zone is characterized by the addition of MgO and K20 and by the depletion of Na20 and CaO. These changes are reflected in the mineralogy of the altered wallrocks by local enrichment in chlorite, biotite, muscovite and cordierite.The mineralized zone is medium- to coarse-grained, well-banded and is composed largely of pyrite, quartz, and sphalerite with subordinate galena and chalcopyrite. Preliminary studies of metal distribution indicate that a lateral zonation is present, with lead enrichment in the central part of the deposit, and copper enrichment toward both ends. Stringer-type copper mineralization has not yet been discovered in the footwall of the Gondor deposit."

Jan 1, 1985

By Ryan W. Siggelkow

Mines today use various methods of mining to extract ore. Because of the dangerous nature of many of these processes, remotely controlled LHD machines are being used to extract the ore from the draw point. The remote control system, although being made safer all the time, has remained virtually unchanged for many years. The basic functionality is an operator switching the machine to remote control, getting out of the cab, walking up a stand, operating remotely, returning to the cab, switching to manual, driving manually, switching to remote, and switching to manual. It seems repetitive, and time consuming, does it not? Networking, convergence, video, voice, and data infrastructures, and other technologies are growing by leaps and bounds in virtually every industry and region, except for mining. From the comfort of the living room couch, a Canadian can play hockey online with full voice conversations over the Internet with someone in Russia in real time. Yet, a mine superintendent must jump through hoops to have a private conversation with the front line supervisor underground. "Is Joe around anywhere?" If Joe hears the message, he will respond. If not, who knows? Maybe he's hurt. Maybe he's not. Where is Joe? Nobody really knows, and that is scary. Today, surface knows that the workers disappeared into the cage at 7:00 a.m. They also know that the workers will probably and hopefully return at 3:00 p.m. Is there not a better way to handle this? With such a complex industry, it seems as if, for the most part, the introduction of new technology into mining has either been overlooked or has been met with some resistance. It is time to step back, look at the process, and see how it can be improved. Key areas of focus will be safety, productivity, dependability, and cost-effectiveness.

Oct 1, 2010

By Peter McGoldrick

This Talk ?Australian deposits in world context ?Geological setting: the importance of the basin fill ?Key deposit features using HYC (McArthur River) and Century as examples ?The difference between Aussies & Canuuks(that is between Australian & Canadian sedexdeposits!) ?Timing of mineralization ?Sources for metals and ore fluids ?What makes a super giant sedexdeposit?

May 1, 2006

By Daniel Cluff

Frozen backfill for mining operations in permafrost must be delivered in such a state so as not to thermally impose on the host rock surrounding the filled stope. The placement process, the material strength demand, and the freezing time delay are the parameters that control the applicability of the method. A two-year research program was carried out in the field and using a laboratory-scale apparatus, designed to simulate a pour of frozen backfill, to study the mixing, thermal properties and segregation. The frozen rock and tailings must be at a below zero temperature and get fully wetted so the surfaces cause adherence of the particles to one another and enhance the solidification of the poured backfill. The results provided a recipe and a process for mix design for open stoping operations in cold regions. The testing evaluated the sensitivity of the test parameters that included the amount of water added in the mix, the temperare of water, the rockfill/tailings ratio, and the temperature of solid constituents.The paper presents the result of this environmentally friendly, innovative technology. The distribution of the materials and the mixing process are instrumental in achieving the properties required for open stoping applications.

Oct 1, 2010

By V. Baboudjian, R. J. Geren, J. Thiriar

"The electrolytic tankhouse at CCR was recognized by management as lagging behind modem refineries in terms of productivity, energy efficiency and controls. The operation was also burdened by high maintenance costs of cells, floors and electrolyte recirculation systems.A bench marking program was started in 1986 to evaluate processes and other technology by visiting major copper refineries in North America, Europe and Japan. The basic principles necessary to optimize the operation were defined, and a program calledCCR 2000 was prepared for approval of the necessary capital investments.This paper describes the results obtained to date and outlines the remaining work to complete the modernization program, in particular, the control of electrolytes, the elimination of the Baltimore groove and studies to modernize the stripping operation or adopt permanent cathode technology.IntroductionThe CCR Refinery of Noranda Copper Smelting and Refining (Noranda Minerals Inc.) , in Montreal East, is one of the world 's largest custom copper and precious metal refineries with a capacity to refine 350000 tonnes of copper per year. The silver refinery, which treats the copper tankhouse anode slime, foreign slime and precious metal ingots, produces 800 000 kg of silver, 26 000 kg of gold and 3800 kg of platinum-palladium concentrate annually. Copper anodes are received from the Horne Smelter at Rouyn-Noranda, Quebec, and Mines Gaspe Division in Murdochville, Quebec. CCR also refines anodes from Hudson Bay Mining and Smelting Co. Ltd. in FIin Flon, Manitoba, and remelts anode scrap along with blister and purchased copper scrap ."

Jan 1, 1993

By J. Locat, G. Parker, D. Turmel

ABSTRACT Since 1964, the Iron Ore Company of Canada has deposited iron ore tailings into Wabush Lake in western Labrador, Canada. From 1999 to 2008, the authors completed multibeam bathymetric and sampling surveys and an airborne LiDAR survey. These data were integrated to study the evolution of the tailings delta shoreline and lakebed elevation. Subaqueous channels evolved between surveys, influencing the tailings depositional pattern. With this analysis it is possible to evaluate the effect of disposal strategies on the delta topset and tailings accumulation. This project uniquely couples marine and terrestrial techniques to follow the fate of tailings in a dispersal system.

Jan 1, 2014

By E. L. C. Martins, M. J. Nicol, D. Majuste, A. D. Souza

The effects of organic compounds on the current efficiency (CE), morphology, crystal structure and mechanical properties of the metal deposited during the electrowinning of zinc are described. A flotation collector and lubricating oil were selected based on observations made during the industrial production of zinc from silicate ores, in Brazil. The analysis by Fourier transform infrared spectroscopy of these compounds, which may be present in minor amounts in the electrolyte solution, indicated the presence of a polar amine group in the collector, while the lubricating oil is a non-polar compound. The average CE value obtained from organic-free industrial solution was 91.15 ± 0.26 %. The CE dropped to 54.35 ± 0.73 % in the presence of 100 mg·L-1 of collector in the solution, and a negative effect was also observed in the presence of similar amounts of oil (88.84 ± 0.61 %). The characterization of the deposits by scanning electron microscopy and X-ray diffraction revealed the formation of pores in deposits obtained from solutions containing the oil, while a different growth pattern (perpendicular zinc platelets) was identified when the flotation collector was added to the industrial solution. In the presence of these contaminants in the solution, guided-bend tests revealed that the deposits have a higher resistance to deformation, but lower ductility, properties that may affect the performance of the stripping stage. As a result of this work, simple control and optimization actions were applied in the industrial plant, which resulted in important improvements in the electrowinning process.

Jan 1, 2014