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By S. L. Gertsman

Canadian steel foundry practice has made marked progress during the past decade. Equipment suppliers, development engineers, and foundry personnel have focussed their attention on every phase of the foundry operation, with a resulting lower demand on manpower and materials. Also, more rigid specification requirements as to dimensional tolerances and quality have necessitated improvement and increased control at every stage from the pattern shop to the cleaning room. The growing trend toward mechanization is clearly evident. Equipment such as sand mixers, sand reclamation systems, material handling devices, moulding machines, core blowers, etc., is being increasingly employed by the steel foundryman. This equipment not only increases production but also tends to lessen the human variable so prevalent and disconcerting in the early days of steel founding. The result has been an improved and more reliable steel casting, which is gradually obtaining wider acceptance by design engineers. The purpose of this paper is to discuss briefly some of the practices being used, and also the direction of development that is being pursued by Canadian steel foundrymen.

Jan 1, 1948

By J. E. Terry

This paper outlines the steps that are being taken to close the gap between training and industry and indicates areas in which more work needs to be done. Although based on experience in the Maritime Provinces, it is applicable to industrial and educational studies across the length and breadth of Canada.

Jan 1, 1970

By J. E. Nesset

Significant progress has been made over the past few years on characterizing and understanding the hydrodynamic properties of frothers and collectors and their effect on flotation performance. This new understanding of the relationship between chemistry and hydrodynamics has dramatic implications for how flotation circuits should be controlled and optimized. Previous work has shown that choosing a frother of the right 'strength' is critical to the optimization process, and the work and discussion presented here serve to strengthen the argument. In addition, we know that collector chemistry may also influence hydrodynamic properties and needs to be taken into consideration. To achieve the desired outcome, the overall system of reagents and operating parameters must be considered. This paper describes and discusses some of the findings from recent research on frother and collector chemistry effects (on hydrodynamics), and how this knowledge can be used to improve flotation performance. Examples from plant experience are discussed.

Jan 1, 2009

By G. S. Hume

THE discovery of natural gas with naphtha in 1924 in the Upper Palaeozoic limestone of Turner Valley, 35 miles southwest of Calgary, has led to continuous developments in this field. Drilling undertaken soon after this discovery demonstrated that the anticlinal structure was in reality a major drag-fold cut off on the east side by a westerly inclined fault of large displacement. The faulted edge of the .limestone at depth determines the eastern limits of the field, which between 1924 and 1936 was shown to have a gas area 14 miles long by about 1 mile wide. Since the strata dip westerly, away from the axis of the fold, drilling becomes progressively deeper to the west and, with the advent of deeper drilling, crude oil was discovered in 1936 on the west flank of the structure but in the same porous reservoir rocks as the gas on the crest and upper parts of the fold. Since 1936, drilling has been undertaken wholly for the production of crude-oil and at present two producing areas have been found within the Turner Valley structure. The larger of these, at the south end of the field, in the vicinity of Highwood river, has a length of about 4 3/4 miles and a proved width of one mile, whereas the smaller, in the north end of the field, south of the north fork of Sheep river, has only a few producing wells.

Jan 1, 1939

By W. G. Worcester

THE chief object in presenting this paper on bentonite is to attract general attention to one of the least known and most neglected industrial minerals of Canada, a mineral of extensive commercial possibilities, as evidenced by its development and exploitation in other countries, principally in the United States and Germany; countries upon which some of our most important Canadian industries are dependent for their supply of special clays, such as Fuller's earth and activated bentonite. It was in view of these conditions and the knowledge of the presence of large quantities of bentonite in the Canadian West that the work here reported on was under-taken. While the investigational studies have not been completed, the results indicate that among the many samples tested there are some of real merit and industrial importance. While it has been the author's privilege to examine deposits and samples of bentonite from all of the Western provinces, his chief activities in the field and in research studies have naturally been confined largely to Saskatchewan materials. Notwithstanding this, however, this paper is presented in the hope that it may stimulate a more general interest in, and study of, Canadian bentonites as a whole, a matter of such importance that provincial boundary lines should be overlooked. GENERAL CHARACTERISTICS OF BENTONITE According to Schurecht and Donda (1), bentonite is commonly composed of the mineral montmorillonite, (Mg,Ca)O.Al203 5SiO2 .nH2O, though some are known to consist of beidellite, Al2O3 3SiO2.nH2O: where n is approximately 4, and in certain cases the Al2O3 may in part be replaced by Fe2O3. For present purposes, however, it may be sufficient to state that, in general, bentonite is a "soapy' clay-like mineral or group of minerals composed largely of hydrous aluminium silicate, but frequently carrying small percentages of the alkalies, alkaline earths, and free silica, as well as silicates, gypsum, and other admixed detritus such that purification is usually necessary.

Jan 1, 1937

"NI 43-101 is a rule that governs how issuers disclose scientific and technical information about mineral projects to the public in Canada. The disclosure standards apply to oral statements as well as written documents and websites. NI 43-101 does not apply to disclosure concerning petroleum, natural gas, bituminous sands or shales, groundwater, or coal be methane. NI 43-101 first came into force on Feb. 1, 2001 and was revised in December 30, 2005. As a “National Instrument”, the law has been passed in each provincial and territorial legislature across Canada.“PART 1 DEFINITIONS AND INTERPRETATION 1.1 Definitions - In this Instrument “adjacent property” means a property(a) in which the issuer does not have an interest;(b) that has a boundary reasonablyproximate to the propertybeing reported on; and (c) that has geological characteristics similar to those of the property being reported on; “data verification” means the process of confirming that data has been generated withproper procedures, has been accurately transcribed from the original source and is suitable to be used; “development property” means a property that is being prepared for mineral production and for which economic viability has been demonstrated by a feasibility study; “disclosure” means any oralstatement orwritten disclosure made by oron behalf of an issuer and intended to be, orreasonablylikely to be, made available to the public in a jurisdiction of Canada, whether or not filed under securitieslegislation, but does not include written disclosure that is made available to the public only by reason of having been filed with a government or agencyof government pursuant to a requirement of lawother than securities legislation; “early stage exploration property” means a property that has(a) no current mineral resources or mineral reserves defined; and (b) no drilling or trenching proposed; in a technical report being filed in a local jurisdiction; “exploration information” means geological, geophysical, geochemical, sampling, drilling, trenching, analytical testing,assaying, mineralogical, metallurgical and other similar information concerning a particular property that is derived fromactivities undertaken to locate, investigate, define or delineate a mineral prospect or mineral deposit; “feasibility study” means a comprehensive studyof a mineral deposit in which all geological, engineering, legal,operating, economic, social, environmental and other relevant factors are considered in sufficient detail that it could reasonably serve as the basis for a final decision by a financial institution to finance the development of the deposit for mineral production; “historical estimate” means an estimate of mineral resources or mineral reserves prepared prior to February 1, 2001;“IMMM Reporting Code” means the classification system and definitions of mineral resources and mineral reservesapproved by The Institution of Materials, Minerals, and Mining in the United Kingdom, as amended; “JORC Code”means the Australasian Code for Reporting of Mineral Resources and Ore Reserves prepared by the Joint Ore Reserves Committee of the Australasian Institute of Mining and Metallurgy, Australian Institute ofGeoscientists and Mineral Council of Australia, as amended; “mineral project” means any exploration, development or production activity, including a royalty interest or similarinterest in these activities, in respect of diamonds, natural solid inorganic material, or natural solid fossilized organic material including base and precious metals, coal, and industrial minerals;"

Jan 1, 2003

By J. V. Thirgood

"Reclamation legislation was introduced in British Columbia in 1969 amidst public concern and controversy. This paper reviews this legislation as it relates to coal mining, and how it is being implemented.Although the principles of land reclamation are reason-ably well understood, reclamation of industrial wasteland has never previously been attempted under such rugged conditions as occur in the Canadian Rockies and a new methodology is being developed.The resolution of the technical and organizational problems involved are discussed and the techniques and experiences described."

Jan 1, 1971

By A. O. Dufresne

The mineral wealth of pre-Cambrian rocks in Canada has been the subject of much study by geologists and engineers (members of this Institute), particularly so in the past few years, following discoveries of mineral deposits in areas far a part. This interest is well worth sustaining knowing the numerous rich producing mines within the pre-Cambrian formations, and the vast area covered by its rocks throughout this country. The pre-Cambrian has yielded minerals, both metallic and non-metallic; of these a much diversified list could be made. In more than one district we can point to mining as being responsible for the opening up of new sections, attracting a population into regions which otherwise would have remained virgin land of little commercial value. In these pre-Cambrian formations are found the rich copper deposits of Michigan, producing without interruption since 1845, and from which seven billion pounds of copper has been won; while in Minnesota and the adjoining district, at the head of Lake Superior, are mined iron ores which have rendered possible the great steel manufacturing industry of United States, the base of the economic structure of that wealthy country. The pre-Cambrian has given Canada the nickel-copper mines of the Sudbury district, the silver deposits of Cobalt and the gold camps of Porcupine and Kirkland Lake. With all of these our members are familiar; and it suffices to mention them to bring to mind pictures of the wealth and 'the growing population, in a word the importance of mining in?those sections of the country.

Jan 1, 1926

By Allan R. Punkkinen

Safe extraction of the valued ore resource in the deep levels of VALE Creighton Mine has progressed in a pillar-less fashion using vertical retreat, slot-slash and uppers retreat methods since the cessation of ?cut and fill? mining in the late 1980?s. Sequencing of the panel extraction and filling has been the key to successful exploitation of high stress orebodies at depth. In late 2010, discussions between the Operating Department and Creighton Ground Control revealed an opportunity to evaluate a trial primarysecondary sequence in the west end of the 400 Orebody at the 2340m horizon. To manage the trial primarysecondary project, a high level risk analysis and management of change was carried out to mitigate potential danger. As part of the requirements, an instrumentation project was conducted in the hanging wall and footwall bottomsills of the secondary panel and within the secondary panel itself. The extraction sequence was modeled with Map3D® software, confirming high stress levels with the advance of the primary panel. Enhanced ground support was installed based on modelling results. A key objective of the instrumentation project was to verify support system response to mining and to obtain knowledge in regards to the behavior of the stope. This paper describes the first time that this type of new innovative instrumented rockbolt technology had been used in a hard rock mining environment. Understanding of the physical deformation mechanisms of ground support in response to high stress conditions is the basis for an effective ground control strategy. The data played an important role in subsequent enhanced ground support system design at the mine and importantly, established the fact that the secondary pillar had not totally failed. Subsequent cavity monitor results helped establish that fact.

Jun 1, 2012

By T. Hofbauer, M. J. Dry, G. B. Harris, C. W. White

"Urban Mining is a term that is increasingly being used, and represents an appreciable source of secondary materials for the metals extraction industry, a source that does not incur mining costs, but does, at present, incur considerable disposal costs. Electric Arc Furnace Dust (EAFD) is probably the most common of these materials, with an estimated global production of 8 million tonnes annually, of which 1 million tonnes is generated in North America. The contained annual metal value in EAFD at current prices is of the order of $6 billion, yet, apart from the zinc, virtually none of this is recovered.Despite many attempts over the years, with pyrometallurgical, hydrometallurgical or hybrid processes, currently the only commercially viable method of treating these materials is smelting in a Waelz Kiln (or a Rotary Hearth Furnace), which essentially recovers only the zinc, in an impure oxide form, and generates a secondary slag waste, which is still toxic and requires disposal. This paper describes the development of a chloride-based treatment process to recover all components of the EAFD in a marketable form, which centres around the novel hydrochloric acid recovery and recycle operation. Laboratory, miniplant and pilot plant data are presented, leading to the definition of a viable process flowsheet enabling the recovery of pure iron and zinc products (the principal components of EAFD), together with secondary products such as copper, silver, lead, cadmium, magnesium and manganese. A rigorous mass-energy balance is used to examine the preliminary economics involved."

Jan 1, 2014

By T. Holmes, S. Davison

"A surge bin at Agrium’s Vanscoy potash operations has been plagued with flow, wear, and corrosion issues since being built in 1967. The culprits? The bin’s carbon-steel construction, geometry, and the resultant funnel-flow pattern are the root causes. An investigation and cost analysis indicated that hopper redesign and retrofit would increase production and reduce maintenance and capital costs. The retrofitted bin provides safer, more reliable operation and has a much longer predicted working life. Using this example, the authors describe bulk-solids-flow theory and highlight the importance of customizing bulk-material-handling-system design using appropriate flow properties to improve reliability, safety, and cost effectiveness.RÉSUMÉ Depuis sa construction en 1967, un réservoir intermédiaire de l’exploitation de potasse Vanscoy d’Agrium connaît des problèmes de débit, d’usure et de corrosion. Les responsables ? La construction en acier ordinaire du réservoir, sa géométrie et la structure de débit en résultant au niveau de la carotte en sont les causes fondamentales. Une étude et une analyse des coûts indiquaient que la restructuration et la rénovation de la trémie permettraient d’augmenter la production et de réduire les coûts d’entretien et en capital. Un réservoir rénové permet de renforcer la sécurité ainsi que la fiabilité de l’exploitation, et sa durée d’activité prévue en est augmentée. En se fondant sur cet exemple, les auteurs de l’article décrivent la théorie du débit de matières solides en vrac et insistent sur l’importance de personnaliser la conception du système de manutention des matériaux en vrac à l’aide de propriétés rhéologiques adaptées afin d’améliorer la fiabilité, la sûreté et la rentabilité.INTRODUCTIONIn early 2013, Agrium’s Vanscoy Potash Operations (VPO) engaged Jenike & Johanson Ltd. (J&J) to provide testing, consulting, and structural engineering services related to proposed modifications to the 270 t special standard product surge bin, which Agrium planned to undertake during a two-week shutdown in August 2013. The bin, which had been plagued with flow, wear, and corrosion issues for its entire working life, was essential for the continuous operation of two of VPO’s compaction plants and for efficient dispatching to loadout. The bin often experienced product hang-ups, clumping on the walls, and plugging at the hopper outlet. Two recent unscheduled mill shutdowns had been partially attributed to flow issues in the bin due to clumping and product plugging up at the screws. These problems increased maintenance costs, limited production capacity, and degraded product quality. Holes and paper-thin sections in the bin walls discovered during a 2013 inspection revealed the potential for major hot material leaks or even structural failure. Either issue would stop plant operations until the bin could be repaired or bypassed. Clearly, the bin cone had reached the end of its life and required replacement."

Jan 1, 2018

By J. Scrimgeour

"The word ""instrumentation"" has expanded from its original meaning, which in engineering perhaps referred to measuring apparatus alone. In its broadest form, it now includes sensors, display instrumentation, standard pack-aged controllers and, most recently, the use of stored program computers for on-line process control. The paper traces the evolution, in tutorial form, of the successive application of mechanization, measurement instrumentation, automatic control, central operating systems, programmed control, process computer control, direct digital control and, finally, hierarchies of computers used for process control and corporate management as a fully integrated business system. In the field of industrial minerals, the cement industry has seen the most widespread acceptance of these techniques. Computer control has been accepted as the way of life for the blending of chemical materials and for on-line control of the cement kiln. Accordingly, the cement application is selected for further presentation in the paper. This illustrates the trend progressing from control of single loops on process variables toward the objective of total control of the product quality. The economic justification for instrumentation, centralized control, automatic control and computer control is .discussed with reference to savings in fuel, maintenance, operating labour, depreciation, power and product quality improvements."

Jan 1, 1967

By S. B. V. Stewart, W. W. Forsyth

"Since the Mathew's method for open stope design was first proposed by Golder Associates in 1980 it has been applied at a number of mine sites in Canada. The initial hypothesis was based on a relatively small amount of data and the intervening period has allowed the collection of a significant amount of new data to test the validity of the method.This paper examines a brief history of the evolution of rock mass classification systems to provide background and emphasize their empirical and non-rigorous approach. It also presents the new data which appear to indicate that the initial hypothesis was reasonably good. The modification to the original graph proposed by Potvin is discussed as well as the applicability of the method to predicting the onset of caving. The original graph has been updated and has been subdivided into four zones described as ""stable""; ""potentially unstable""; ""potential major failure""; and ""potential caving"". The method is recommended as a useful open stoping design tool provided it is recognized that it is not a rigorous design method.Finally the paper proposes a recommended approach for application of the method by would-be users and addresses some typical pitfalls that may be encountered."

Jan 1, 1995

By Stefan Planeta

On discute les performances techniques et économiques des méthodes d'exploitation à haut rendement dans les mines métallifères au Canada. L'accent est mis sur la dilution et pertes des réserves minières et sur les coûts opératoires et totaux. Une analyse technique de quelques opérations minières est également effectuée. Il ressort de cette analyse que les résultats réels des opérations minières en cours diffèrent souvent de ces planifiés suite à la dilution du minerai et aux pertes importantes des réserves minières. On propose, définit et discute un certain nombre des facteurs de performances technologiques et économiques pour pouvoir mieux apprécier les problèmes rencontrés dans plusieurs mines en opération. À l'aide des études de cas on démontre impact négatif de la dilution et des pertes additionnelles des réserves minières sur la rentabilité des opérations en cours et sur les nouveaux projets miniers. On conclut, que l'application des indicateurs proposés donnerait un outil valable, aux opérateurs miniers, aux niveaux de la planification, du suivi des travaux d'exploitation et d'éventuelles études comparatives entre les différentes situations minières. ABSTRACT The paper discusses technical and cost performance of bulk mining methods in Canadian U/G metal mines. It focuses on ore dilution, ore reserves losses as well as on operational and total cost. Technical analysis of some mining operations has been performed. It indicates that due to dilution and significant reserves losses, the actual results of mining operations often differ substantially from those planned. The paper proposes, defines and discusses several indicators quantifying technical and economical performance in order to assess better the problems encountered in several operating mines. The case studies presented here have demonstrated an adverse effect of dilution and additional reserves losses onto profitability of existing operations and new mining projects. It is concluded that the application of the above mentioned indicators may be beneficial for mine operators. They may become a very useful tool at the stages of planning, follow-up of mining works and with regards to comparative studies between different mining situations.

May 1, 2001

By A. M. Salomon de Friedberg

With respect to impurities, HBM&S' copper smelter, located in Flin Flon, Manitoba, is in an unusual position. In addition to the usual concerns, the fact that copper and zinc production at Flin Flon is closely integrated results in the unique situation where feed to the copper smelter typically contains 7% to 8% zinc. This paper discusses the ramifications to copper smelter operations resulting from the marriage of HBM&S' metallurgical plants. Distributions of impurities (specifically Zn, Pb, Ni, As, Bi, Sb, and Cd) are presented and operating practices designed to reduce the impact of impurities on anode copper quality are detailed.

Jun 1, 1993

By A. M. Salomon de Friedberg

"With respect to impurities, HBM&S' copper smelter, located in Flin Ron, Manitoba, is in an unusual position. In addition to the usual concerns, the fact that copper and zinc production at Flin Ron is closely integrated results in the unique situation where feed to the copper smelter typically contains 7% to 8% zinc. This paper discusses the ramifications to copper smelter operations resulting from the marriage of HBM&S' metallurgical plants. Distributions of impurities (specifically Zn, Pb, Ni, As, Bi, Sb, and Cd) are presented and operating practices designed to reduce the impact of impurities on anode copper quality are detailed.IntroductionHudson Bay Mining & Smelting Co. Ltd. (HBM&s), has been operating its metallurgical complex located in Flin Flon, Manitoba, since 1930. The smelter and zinc plant were originally separate entities with respect to production. The smelting operation consisted of traditional multiple-hearth roasters, a reverberatory furnace and Peirce-Smith converters. The zinc plant also utilized multiple hearth roasters and then followed with sulphuric acid leaching, purification and electrowinning. The zinc plant also recovered cadmium from a separate purification/electrowinning circuit.The two plants operated essentially independently of each other until rising zinc levels in the copper concentrate and large stockpiles of zinc-rich leach residues prompted the construction of the fuming plant in 1949. The smelter used pulverized coal to reduce zinc oxide present in the reverb slag and then captured the resulting zinc bearing fume in the fuming plant baghouse. The fume was sent to a separate ""oxide roaster"" in the zinc plant where it was first roasted to remove halogens and then leached to recover the contained zinc. This oxide fume became a major source of feed to the zinc plant accounting for roughly one quarter of the total zinc production. Furthermore, through the smelter's treatment of sulphide leach residue, both copper and zinc recoveries were improved for the over-all complex."

Jan 1, 1993

By Catalin Florin Petre, Elahe Ghasemian Langeroudi, Abdelaaziz Azizi, Éric Proulx, Caroline Olsen, Paul Blatter, Faïçal Larachi, Claude Gagnon

"The recovery of gold from ores is often accompanied by the release of other species in the leach solution. This state of affairs leads to depleted free cyanide levels in the slurry. Therefore, separation and quantification of these cyanicides and free cyanide at different stages of the cyanidation process as well as in waste solutions is crucial to provide mitigation tools by preventing leaching of deleterious metals for environmental considerations.COREM and the research group of Prof. Larachi have been working together on the control of gold passivation and cyanicides during cyanidation for several years. Previously, a first capillary electrophoresis (CE) protocol for the speciation of sulfur and cyanicides (SCN-, Cu, Fe) during cyanidation of gold complex sulfide ores was developed and validated for assessing industrial process water.The separation of zinc cyanide complexes used to be confronted with a number of difficulties due to the weak and/or undetectable cyanocomplexes in formally available CE protocols. Moreover, according to our knowledge, no direct CE protocol exists to separate free cyanide. Therefore, a new study aimed at developing a second CE protocol for the detection and quantification of cyanide complexes of zinc and nickel as well as of free cyanide in the cyanidation process water.To achieve this goal, six common carrier electrolytes such as pyridine, trimellitic acid, 4-methylbenzylamine, sodium chromate, phthalic acid and tris base were studied, using an indirect UV detection method. The best results were obtained using sodium chromate for which all ions were successfully separated and quantified. In addition, the effect of electric field strength, injection volume, electro-osmotic flow (EOF) modifier and background electrolyte (BGE) concentration were examined, while peak height, peak area and noise were considered for optimization.As a result, the new protocol is expected to complete the initial CE protocol by detecting cyanide complexes of zinc and nickel as well as free cyanide. Moreover, analytical determination of free cyanide in the presence of weak cyanide complexes achieved by the new protocol was also compared to conventional titration using silver nitrate solution. This new CE protocol will contribute to applied research and help plants to better understand and eventually control the behaviour of cyanidation circuits."

Jan 1, 2011

By Scott A. Stebbins

Cost evaluation models constructed specifically to evaluate the economic potential of an individually motorized railcar system of ore and waste transport demonstrate that the approach may be considerably more cost effective than traditional rubber-tired haulage methods. The system design places a motorized drive unit on each railcar, as opposed to the more common configuration in which a series of un-motorized cars trail behind a single locomotive. These motorized railcars are directed to various load and dump points by a computerized dispatch system, and as such have the advantage of operating unmanned. In addition, the tractive effort of the rail-type drive system is noticeably more efficient than that of the rubber-tired mode of transport. The savings are realized primarily through comparative reductions in the requirements for labor and, to a lesser degree, energy.

Nov 1, 2011

By Persio P. Rosario

Crushing has proven to be of fundamental importance in mine mill integration at Highland Valley Copper (HVC). Highland Valley Copper has achieved large throughput and good quality control through the gyratory crushers by proper blast design and better gap control. The next step, in optimizing the mine mill relationship, is evaluating the crusher liner wear and its shape influence on performance and product size reduction. To do this a laser measurement device has been developed and data is being recorded on the concave and mantle liner wear. This paper will outline the work to date and indicate specific objectives of the work.

May 1, 2002

By Yongjun Peng, Yufan Mu, Rolf A. Lauten

"Chalcopyrite, a major source of copper, is commonly found associated with iron sulfides, particularly pyrite. The separation of chalcopyrite and pyrite by flotation is difficult due to the galvanic interactions between pyrite and chalcopyrite during grinding and flotation. Galvanic interactions may cause oxidation and dissolution of chalcopyrite, copper activation of pyrite and the formation of hydrophilic iron hydroxide coating. The overall effect may change the floatability of the components and lead to the misplacement of pyrite into chalcopyrite concentrate. The objective of this study was to investigate the effect of lignosulfonate-based biopolymers on the depression of pyrite in the flotation of chalcopyrite with xanthate as collector and the mechanism responsible for the selective depression of pyrite. The flotation results showed that biopolymers depressed the flotation of both copper-activated pyrite and chalcopyrite in single mineral flotation although to different extents. In the flotation of mixed mineral systems, biopolymers significantly depressed pyrite flotation but had a less influence on chalcopyrite flotation. The selective depression of pyrite by biopolymers was due to the preferential adsorption of biopolymers on copper-activated pyrite surface. Galvanic interactions between pyrite and chalcopyrite surfaces promoted copper activation on pyrite. Presence of cuprous ions on pyrite surface favored biopolymer adsorption by the formation of a complex between the cuprous ions and biopolymer molecules. The same galvanic interactions also facilitated chalcopyrite oxidation leading to the formation of hydrophobic polysulfide that enhanced the hydrophobicity on chalcopyrite surface. The biopolymer structure controlled the depression effect. The results showed that the biodegradable biopolymers are promising depressants for pyrite.INTRODUCTIONCopper sulfide minerals, such as chalcopyrite (CuFeS2), bornite (Cu5FeS4), chalcocite (Cu2S) and covellite (CuS), are the major mineral source for copper. They are often found finely interlocked with iron sulfides, especially pyrite (FeS2) (Owusu, Brito e Abreu, Skinner, Addai-Mensah, & Zanin, 2014). Pyrite, as the most abundant sulfide mineral, is perceived as gangue in most cases and should be removed from the associated sulfides to minimize its contamination of the copper concentrate (Owusu, Addai-Mensah, Fornasiero, & Zanin, 2013; Wang & Forssberg, 1991). The commonly used strategy to remove pyrite is flotation (Wang & Forssberg, 1991)."

Jan 1, 2016