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By R. F. Hochstein, A. J. Neale, B. C. Flintoff

"Process control technology holds very significant potential benefits for many mineral and coal processing plants. The impact can be expected in terms of performance improvements (e.g. increased throughput, better quality control, higher availability), through reduced operating costs (e.g. lower reagent consumptions, manpower reductions) and in the form of intangibles (e.g. reduced vulnerability to manpower turnover, increased productivity in the user group). However, the installation of a process control system will represent considerable capital expenditure and will generate an operating cost. No management team would approve the funding for such a project without some reasonable measure(s) of the profitability of a proposed system. This paper describes a methodology for addressing the justification problem. Of particular interest is the approach to quantifying performance improvements, frequently found to be the predominant benefit of process control.INTROPUCTIONProcess control has become widely recognized as an essential component of any processing operation. It has direct impact on productivity, process efficiency and product marketability. The reported pay backs associated with successful installations underscore this observation. As a consequence, many operators who have little in the way of process automation are looking to initiate control projects, while those who currently enjoy some level of automation are looking to upgrade existing control systems (= process + instrumentation + hardware + software + operators + support). While the emphasis here would appear to be on retrofit process control projects, new plants, or those currently in the design stage, will usually find themselves in one of these categories shortly after startup 1."

Jan 1, 1990

By John Wilson

"The Rietveld numerical method was used to calculate the relative abundances of phases in both synthetic binary mixtures and synthetic and natural ores, using X-ray diffraction data. The results were compared with those of image analysis and a chemical method. The ranges of the relative errors were estimated. The Rietveld method is found to be acceptable for determining the abundances of major and minor phases and the amorphous component of partially crystalline samples. In complex mixtures, where there are several trace phases (~<2 wt%) present, the technique becomes less accurate. It is most useful as an alternative technique to image analysis when sample preparation is problematic or sample particle sizes are sub-micron. It is a manual method which requires user input during the fitting process, but is both simpler and faster than image analysis due to the reduced set up time and sample preparation required. It is now implemented at CANMET as a technique for quantitative analysis.INTRODUCTIONUntil recently, the Applied Mineralogy group at CANMET used only image analysis and chemical techniques to determine phase quantities. An effort to develop quantitative X-ray diffraction (XRD) has been on-going for several years. Initially, the reference intensity ratio (RIR) method with external standards was tried with some success (Szymanski and Petruk, 1989). The main difficulty with this technique was finding adequate standard material for each phase present in the sample. This shortcoming made the method ultimately impractical, given the wide variety of materials which come to the laboratory for analysis.The Rietveld refinement method of quantitative XRD (Hill et al 1993, Mumme et al 1996), in contrast, requires no standards and requires minimal sample preparation and therefore a more rapid turnaround compared to image analysis. The Rietveld method also has advantages over image analysis in that it can identify and quantify polymorphs, ultra fine materials and many types of hydroxide products. As well, it is useful for analyzing materials such as bauxite or talc, which do not polish well enough for making mounts of the quality required for image analysis. To quantify amorphous material and phases which are present in amounts below the detection limit of XRD, the addition of a standard material is still required. However, in such cases only one standard is needed, which is alumina."

Jan 1, 2003

By Jodi Roberts, Curtis Deredin, Jean-Guy Paulin

"Since the establishment of the Six Sigma quality improvement program in 2001, several projects have been successfully carried out in the copper-lead, zinc, copper separation, lead upgrading and bulk flotation circuits in the Brunswick Concentrator.This paper provides an update on the process improvement initiatives that have taken place since 2004 using the Six Sigma methodology:•,The recirculation of warm water to the flotation circuit (to save on energy costs)•,Installation of a heat recovery tower to recuperate the heat lost from the zinc dryers•,Installation of an extra row of cleaner-scavenger cells for the copper-lead circuit for extra capacity, and a new reagent scheme for the copper separation circuit that have increased copper and lead recoveries.INTRODUCTIONThe Brunswick Mine Concentrator (Xstrata Zinc Canada) is located near Bathurst, New Brunswick and is one of the world’s largest lead/zinc mines. Milling of ore commenced in 1964 from the No. 12 orebody, with an expansion in 1966 to accommodate ore from the No. 6 open pit mine. The concentrator utilizes selective flotation to produce zinc, lead, copper, and bulk lead/zinc concentrates. The ore is a complex massive sulphide, consisting of approximately 20% valuable minerals, 60% pyrite and 20% silicates.Figures 1, 2, and 3 illustrate the historical annual average metallurgical performance and process improvements achieved at Brunswick Mine for the zinc, lead and copper concentrate products. The objective is to continuously direct metallurgical performance towards increasing grades and recoveries while minimizing operating costs."

Jan 1, 2008

By M. P. Hay

"For a model to be successful it must address the concerns and needs of a target audience. Further, the model must demonstrate the same patterns of behaviour as the real system, and need only be complex enough to meet this objective. If the model is too complex it can become unusable to those who need it most.With this in mind, SUPASIM has been developed for the practical metallurgist requiring only laboratory flotation rate data as input. Some 35+ successful plant simulations have been completed since 1985. The approach of SUPASIM is to characterise an ore, organise information in an understandable way and add structure to the complex flotation situation and hence support the metallurgist to interpret the relationship between variables and optimise the flotation process.The paper describes the basis on which the model was developed and sets out to provide an insight into interpreting laboratory flotation kinetics and their physical meaning in a production plant and the influence floatable gangue has on float performance and plant design. A case study illustrates how the ratio of slow floating mineral to gangue can influence circuit design and improve recovery on a plant scale.INTRODUCTIONThere is an enormous amount of useful data in the results of a laboratory scale rate test. Each variable of fraction and rate, for mineral, metal and gangue has a physical meaning in the plant. The link between float kinetics and the plant in respect of recovery, grade, pulp density, pulp flowrate, residence time, number of stages of cleaning and circuit configuration has been established by the author in the process of developing SUPASIM."

Jan 1, 2005

By J. A. McLennan

Geological uncertainty is an unavoidable characteristic of all mining projects since only limited information is available from sampling. Mine planning and development decisions with significant economic consequences are made when the geological heterogeneity is inherently uncertain. Geostatistical simulation is preferred over kriging because the methodology provides alternative property realizations that can be combined into a model of geological uncertainty. Geological uncertainty can be transferred into production uncertainty, which can help characterize the economic risk of the project. This paper presents a case study for the Pogo property, being prepared for development near Fairbanks, Alaska. The exact dimensions, grades and production predictions have been modified; however, the methodology is illustrative. The geostatistical methodology consists of (1) assembling the relevant drillhole data and establishing a suitable coordinate system, (2) calculating the target distribution, (3) creating a model of spatial correlation, (4) generating multiple realizations at a small scale and (5) linearly averaging all the realizations to the chosen selective mining unit (SMU) support size. The geostatistical model is then used to calculate production uncertainty.

May 1, 2004

By Pierre Lacombe

"The operation of the Louvicourt Mine will have to rely on stringent grade control and on the optimization of the amount of blocked ore made available per given development effort. All of the above being necessary to obtain the highest throughput at the lowest mining cost.To assist in achieving these objectives, the need for production of a competent fill with short curing time was recognized early by the project partners. As well, operating costs associated with the selected method should be as low as possible while meeting the technical criteria.A feasibility study comparing filling methods showed potential benefits in all aspects of the paste fill use, except for its higher capital costs and increased operational complexity. This last consideration was tackled by the conservative design approach adopted in the flowsheet development of the paste fill plant.Since commissioning of the plant has just been completed at this time, the paper will focus on the feasibility study and its background, the design of the plant and testwork results at pilot plant and plant scale.RésuméLe succès de l 'opération de Louvicourt Mine dépendra d' un contrôle serré des teneurs du minerai et de la maximisation de la quantité de minerai développée par effort uni ta ire. Ces critères devant etre respectés afin d'obtenir le taux de production le plus élevé au coût le plus bas.De façon à satisfaire ces contraintes, les partenaires du projet ont reconnu tôt la nécessité de produire un remblai de qualité tout en maintenant un temps de curage court. De plus, les coût d'opération associés a cette opération se devaient d'être des plus avantageux sans sacrifier l'atteinte des objectifs techniques.Une étude de faisabilité comparant différentes méthodes de remblayage a démontré que le remblai en pâte offre des aspects positifs sous taus les angles, si ce n'est de son coût en capital initial élevé et de sa complexité relative d'opération. Ce dernier point fut considéré de près par l'adoption d' une approche conservatrice lors de la conception de l'usine de rernblai.Puisque la mise en service de l'usine n'a été faite que les détails de l 'étude de faisabilité et ses fondements, 1 'usine et des résultats d' essais obtenus a l'échelle de l'usine seront discutés."

Jan 1, 1995

By B. M. Hamilton

"IntroductionTHE PROCEDURE and technique for drilling holes has probably undergone as great a change during the past ten years as any one of the other operations conducted in hard-rock mining. During this period, we have seen a change from the heavy leyners and drifters to the light jackleg type of drill machine; from steels that were forged and hardened on the bit end to the inserted •carbide-tipped rod, from the necessity of providing special bit-end fabrication and beat treatment of shank steels to the simple grinding or turning of a plain section on a shank with no heat treatment required for bit attachment.When the steel maker was first called upon to manufacture a hollow drill rod, it was required that the steel must not only have sufficient strength and fatigue resistance to cope with the stresses of service, but also must be capable of being heat treated on the bit end to a high hardness for resistance to wear and abrasion . Little was known at that time about alloy steels and the beneficial effects to be gained from additions of chromium, nickel , and molybdenum. So it was that the plain 0.80 per cent carbon analysis was selected, since it had already proven to be a suitable grade for chisels, hammers, and other such shock tools. This grade has long endured the test of time and is still used in considerable tonnage today, particularly by the construction industry.As the metallurgist learned more about the influence of alloying elements, a new hollow drill analysis was placed on the market in the early 'thirties'."

Jan 1, 1954

By Dolea Gabriel Gheorghe

In the present paperwork is proposed an economical-mathematical model (fuzzy) that aims optimize the technological variants of the mechanized coal face. By fuzzification, the issues to solve become more flexible and allow the decision maker to acquire more variants for the functions objectively established. The description of technological solutions is carried out by a set of controllable variables of "category" type by which the type of the machinery is defined within the frame of the actual geological & mining conditions. In the paperwork are used concepts of "successions graph" and "matrix of compatibilities"; with their help a methodology to choose between different technological variants of coalfaces is proposed. It treats the problem of developing the functions that express the membership degree in vague concept. In the end it is presented an assessment procedure for the technological variants of mechanized coal face.

Oct 1, 2009

By J. E. Sepulveda, R. Morrow

"The Linear Wear Theory provides a reliable framework for the assessment of grinding media performance at full scale. This theory can be applied for analyzing grinding media consumption rates in any given grinding operation as well as the evaluation of alternative grinding media products, based on actual operational data, correcting for conditions like ore hardness, feed and product sizes, mill power and circuit throughput; all of them unrelated to the grinding media intrinsic quality attributes. A series of Moly-Cop Tools 3.0 applications have been developed to facilitate the calculations involved. Moly-Cop Tools 3.0 is available, free of charge, to all interested parties through the corresponding author.INTRODUCTION Mineral grinding circuit operators recognize the significance of grinding media (balls) consumption on the cost structure of any full scale grinding facility. The effective cost associated with this essential consumable depends on two factors: delivered price and durability (quality) of the grinding media. When evaluating alternative grinding media varieties, there is a well accepted evaluation criterion by which a given media type is considered to be “cost-effective” when its unit application cost – normally expressed in $/ton of ore ground – is shown to be lower than that of a nominal reference condition: Grinding Media Cost = Ball Price x Ball Consumption (1) ($ /ton ground) ($/ton balls) (ton balls/ton ground) Under this criterion, an alternative, higher-price grinding media product could be “cost-effective” if its associated consumption rate is sufficiently lower than the reference media, enough to yield a lower grinding cost, as dictated by Equation 1. For the proper application of the above criterion, evaluators must rely on representative indicators of grinding media quality, ideally independent of most mill operating conditions. In each particular case, ball price is always a known component; however, it is not so evident how media performance (quality) differences amongst alternative product types could be assessed with a reasonable degree of accuracy and precision."

Jan 1, 2014

By Peter Claus

In the last years, supported gold catalysts with particle sizes smaller than 10 nm have attracted a lot of attention. While gold bulk metal is rather inert in chemical reactions and, thus, is of low interest for catalysis, highly dispersed gold particles supported on oxides as TiO2 or ZrO2 show surprisingly high activities in some reactions important for the chemical industry. The oxidation of carbon monoxide at low temperatures is mainly used as model reaction to study the unusual properties of gold catalysts [1]. On the other hand, to evaluate the catalytic potential of gold, other chemical reactions which allow to control also the selectivity have to be considered. The selective hydrogenation of ???-unsaturated aldehydes to allylic alcohols is of both commercial relevance (e.g. in fine chemical and pharmaceutical intermediate production) and specific scientific interest [2]. Note that thermodynamics favors hydrogenation of the C=C over the C=O group (stronger negative free reaction enthalpy of 35 kJ/mol), and for kinetic reasons the C=C bond is more reactive than the C=O group. Thus, in the presence of most of the conventional hydrogenation catalysts, based on Pt, Rh or Pd, -unsaturated aldehydes such as acrolein and crotonaldehyde are hydrogenated predominantly to the saturated aldehydes and only to a minor extent to unsaturated alcohols. Therefore, it is desirable to find catalysts which are able to control the intramolecular selectivity by hydrogenation preferentially the C=O group while keeping the olefinic double bond intact (Fig. 1).

Oct 1, 2003

By C. J. A. Davie

"SUMMARY A practical application of nitric acid oxidation of sulphides, based on the principles of the Arseno process, has been developed for the Cinola ore. Development of the process has been based on testwork conducted by Bacon Donaldson of Vancouver and Hazen Research of Denver, and on conceptual engineering performed by Minproc Engineers of Denver.A comprehensive Stage II report for the project has been submitted to the B.C. permitting agencies, containing provisions for a zero discharge tailings impoundment system and prevention of acid mine drainage. Approval in principle is expected in early 1989.A feasibility study recently completed by Minproc Engineers and Davy McKee Corporation demonstrates that this project can be brought to production for a capital expenditure of C$120 million for a mill throughput of 6,000 tonnes/day and operated at a total direct operating cost of less than $20/tonne.INTRODUCTION The Cinola orebody was discovered in 1970. It is situated approximately in the centre of Graham Island, the largest of the Queen Charlotte Islands. It represents the mid to upper levels of a hydrothermal precious metals system, characterized by intense brecciation and silicification. Gold is associated with finely disseminated sulphides in a breccia matrix and in free form in numerous quartz veins.Ownership of the property has changed hands a number of times, and previous attempts to bring the property to production have failed. Two critical factors have frequently been blamed for difficulty in creating a successful project: namely, process and environment factors, hence the title of this paper.City Resources (Canada) Limited (""City"") acquired the property in 1986, and commenced an aggressive campaign to verify ore reserves, to carry out metallurgical research and to address environmental issues.PROJECT OVERVIEW When the Cinola orebody was discovered, the significance of hydrothermal mineraliza¬tion associated with crustal plate boundaries was not recognized, and for several years, the orebody was considered an uneconomic curiosity. If the type and location of orebody sought by many companies engaged in gold exploration were to be specified, it would probably be a description of the Cinola orebody - it is a large (greater than 1.5 million ounce), low grade (2.45 gm/tonne), refractory ore reserve associated with the Pacific rim crustal plate boundary. The industry appears to have recognized in the past few years that its future lies in the exploitation of such orebodies, and is prepared to come to grips with the technical problems associated with such ores. In this sense, the Cinola orebody might be considered to have come of age."

Jan 1, 1989

By Paul R. Clark

Outline ? Coal As An Energy Resource ? Canadian Clean Power Coalition ? Phase I of the CCPC Project ? CO2 capture options ? Gasification ? CO2 use ? Results ? Phase II Plans ? Next Steps TransAlta - Profile ? 9,726 megawatts (MW) of capacity ? 46,877 gigawatt hours (GWh) produced at an average plant availability of 88.4% ? 47 facilities in four geographies: Canada; the U.S.; Mexico; and Australia ? Fuel mix of coal (62%), gas (26%), hydro and renewables (12%) ? 23.2 million tonnes of coal mined ? 47.0 million gigajoules (GJ) of gas consumed

May 1, 2004

By Stephen L. Chryssoulis, Daniela Venter, Stamen Dimov

"Comparative surface analysis of floated and rejected free gold grains from a number of full scale benefication plants and from pilot plant testwork, has shown silver (the most common impurity in gold) and sulphur invariably in greater concentration on floated gold grains, implying that they assisted gold flotation (gold activators). Collector loading measurements on individual gold grains from concentrates of staged rougher flotation tests on a cyclone U/F product of a pyritic gold ore, revealed first progressively lower concentrations of the collector monomer on gold from each follow-up concentrate and secondly a direct proportionality between the surface concentration of silver and the collector monomer. These two observations leave no doubt that silver activates gold and that collector monomers play a significant, previously not fully recognized role in gold flotation.INTRODUCTIONGold to some degree is naturally floatable in industrial systems, which means that it can be recovered without collector addition (Marsden and House, 1992). This is due to the adsorption of hydrocarbons and deposition of sulphur, which are dependent on the metallic properties of gold, particularly its high electrical conductivity, which allows surface electrochemical reactions to occur catalytically and selectively. Cyclic voltammetry has shown that gold can be rendered hydrophobic by deposition of a surface layer of sulphur (Sº) from S2- and HS- solutions (Walker et al., 1984). Twenty monolayers of sulphur were required to produce a hydrophobic gold surface.However, no sulphide flotation plant relies solely on the natural floatability of gold for its recovery. Gold hydrophobicity is enhanced by the addition of flotation collectors such as xanthates (X), dithiophosphates (DTP), dithiophosphinates (DTPI), mercaptobenzothiolates (MBC) etc., as used in sulphide mineral flotation (Dekok, 1973: Adams et al., 1986). The mechanism invoked in enhancing the hydrophobicity of pure gold with the aforementioned four groups of collectors is similar to that of pyrite, whereby collector anions are oxidized at the gold surface to form dimers (Groot, 1987; Marsden and House, 1992; Basilio et al., 1992) As an example, xanthate ions are oxidized at the gold surface to form the neutral dimer dixanthogen (X2):"

Jan 1, 2003

By John Russell

"The South American mining community leads the world in recognition and adoption of the latest grinding mill relining technologies. Clearly this region has recognised the benefits of improved relining performance.Six of the seven RUSSELL TWIN 8 Mill Relining Systems, ordered to date, are either operating or being manufactured for South American mine sites.This paradigm shift, towards very short relining times, aims at displacing mill relining activities from the critical path of concentrator maintenance shutdown schedules.The first uses of the RUSSELL TWIN 8 Mill Relining System have seen some of the highest SAG mill new liner placement rates ever observed by RME, as would be expected with two, independent Machines working simultaneously in the one mill.The liner-replacement-rate, averaged over the whole reline, is good (27% improvement over single Machine System in the same mill) but short of full potential. This modest result can be attributed to reline crews unfamiliarity with RUSSELL TWIN 8 System operation.This paper compares a sample of conventional (single machine) RME Mill Relining System performance data with one ‘double head’ mill liner handler by others. Early performance of Escondida’s new RUSSELL TWIN 8 System performance is then compared with recent single Machine data from Escondida, immediately prior to RUSSELL TWIN 8 commissioning. RME and Escondida look to constantly improving RUSSELL TWIN 8 System performance as full operational familiarity is achieved.Also, the preparation of this paper revealed a need to develop a global industry standard for mill relining data collection. A web based platform, to develop and then distribute standardised data collection templates, is discussed in Annexure 1."

Jan 1, 2010

By J. B. Gilliatt

The discovery of ore at Wabana was quickly followed by the mining of the ore beds where they outcropped in the land areas. The third phase, as at present carried out, consists of extensive submarine operations, which were commenced in 1908, by driving a pair of slopes out under Conception bay, opening. the mine for a distance of a mile and a half from the shore. Two other slopes, now driven just beyond the shore line, are being sunk to the submarine territory where, it is generally recognized, huge reserves of ore lie under the bay. The process of erosion of the land, the solution and re-disposition of its iron-bearing minerals in thick beds of ore have been considered elsewhere, but these bear small relation to the physical forces which have acted upon the ore-beds since the deposition of the strata. These physical changes are made manifest by jointing and cleavage and faulting. The discussion of these, the relation they bear to each other, and to the folding of the strata, is the purpose of this article. For the benefit of those who may not be familiar with the formation in which the ore occurs, I include a general summary of the geology of Be!! island and its environs; also a description of conditions that prevailed during the period of deposition, so that the reader may appreciate some of the later changes that took place during or subsequent to its emergence from the sea, and the folding or tilting of the strata to the position it now occupies.

Jan 1, 1924

By W. A. Ahrens, J. H. McNamara, J. G. Franek

"An economical, pollution-free process has been developed for the hydrometallurgical extraction of copper from sulphide ores. The extracted copper, in the form of cuprous chloride (CuC/), is converted by reduction to copper metal. The metal is melted and fire -refined into wire bars which meet the standards of electrolytic tough pitch (ETP) copper wirebars. IntroductionThe successful development of the Cyprus Copper Process has been an evolutionary series of events covering a time span of some nine years. The original process, based on an electrolytic membrane cell principle , was abandoned in 1975 because of technical, economic and pollution problems. During the past four years, the pilot plant has been reconstructed based on a new flowsheet and operated successfully in several campaigns, some for as long as four months. The pilot-plant hydro section operates at a 225-lblhr copper rate. In October 1977, a feasibility study was completed by Jacobs Engineering, Pasadena, California. The study showed favourable economic and technical feasibility. Jacob&apos;s studies in 1978-79 revealed favourable comparative economics with other known pyrohydro processes and favourable economies of scale.The Cyprus Copper Process converts copper concentrates of varying composition into copper metal, which has been proven to be equivalent in every way to electrolytic tough pitch copper, suitable for electrical applications. This is accomplished at capital and operating costs which are estimated to be lower than those associated with any other known currently applicable technology. Also, the total energy requirement is equal to or less than any other known process and the process is essentially pollution free."

Jan 1, 1980

By John F. Kearney

After World War II Canada?s fledgling iron ore mining industry developed along the ill-defined Quebec / Labrador border near what became the town of Knob Lake and later renamed Schefferville. For about twenty-five years from 1954 to 1982 Schefferville was the epicenter of Canadian iron ore mining and the foundation of the Iron Ore Company of Canada. In about 1982 it all stopped, shut down, the miners moved away leaving behind a mining camp and a ghost town that have sat idle and almost deserted for the past twenty five years. The story looks set to change with new plans to re-establish the former mining operations in the historic mining camp. This paper outlines the proposal to reactivate the direct shipping iron ore operations in the Schefferville mining camp, and specifically the properties in Labrador owned or optioned by Labrador Iron Mines Limited (?LIM?), a wholly owned subsidiary of London Stock Exchange listed Anglesey Mining plc. The Schefferville mining camp is located about 1,000 km northeast of Montreal. There are no roads connecting the area to southern Labrador or to Quebec. Access to the area is by rail from Sept Iles to Schefferville, or by air from Montreal and Sept Iles.

May 1, 2007

By C. Larsen, E. Goodwin, E. Konigsmann

"This paper describes the development of an innovative effluent treatment process for cyanide and heavy metal removal from tailings wastewaters at Hemlo Gold Mines Inc. Golden Giant operation.The importance of minimizing dissolution of contaminants in the gold leaching circuit is discussed, as well as using recycled water in milling circuits to the fullest extent possible. Finally, a brief description of the role of natural cyanide degradation in the tailings pond is provided.Emphasis is placed on the need for overall water quality management to ensure minimum effluent treatment process costs and complexity while producing excellent quality effluents.1.0 INTRODUCTIONHemlo Gold Mines Inc. owns and operates its Golden Giant Mine located forty kilometres east of Marathon, Ontario. The Golden Giant mine is one of three gold operations exploiting the large gold orebody located in the Hemlo area. The milling facilities include two stage secondary crushing, three stage, closed circuit ball mill grinding with no reagents, thickening, cyanide leaching and carbon in pulp gold recovery unit operations. The average throughput is 3000 tonnes per day of 10 grammes per tonne gold ore. Figure 1.1 shows a schematic flowsheet of the operation."

Jan 1, 1989

"This generic study has been developed in response to the frequently asked question, ""That is the best treatment route for refractory gold ore?"". The study has developed operating and capital costs for many potential treatment routes and they are presented here in a generic form. All costs are in relation to the value of 1.00 given to the base case, a 1000 mtpd bio-oxidation plant, operating at 25% solids and 72 hours residence time.There is unfortunately no simple answer to the above quest ions. The treatment of refractory ores is a complex subject, with many variables, such as mineralogy, chemistry, environment and tonnage. However this study does offer information and relative numbers that we believe will be of assistance to gold metallurgists in obtaining a ""first shot"" at estimating costs.Equally, this technology is a rapidly evolving one. As more plants are commissioned, and test programs completed, better data is constantly being generated. For a generic study of this type to remain useful it will need regular updating and adjustment."

Jan 1, 1989

By Ivan C. Machado

Jaguar Mining Inc. is implementing a 1.1 Mtpy, 7-year LOM gold project in the Iron Quadrangle (?Quadrilátero Ferrífero?), Brazil. Construction is on schedule and startup is programmed for Q2 2010. Mill feed grade averages 4.43 g/t and LOM gold production is estimated at 800,000 oz. The project entails two sulfide underground mines and three oxide/transition open pit mines. A state-of-the-art flotation/gravity concentration/CIP Plant has been designed based on testwork carried out by internationally recognized Canadian, U.S., and Brazilian laboratories. The mass recovery of the flotation section is only ca 10%, while its gold recovery is about 90%. Therefore, the CIP-ADR Plant will treat only 10% of the solids mass contained in the mill feed, while 90% will be fully cyanide-free material that will be partially used to feed a Backfill Plant. The leached tailings will be conveyed to a rather small tailings dam, whose 20- m3/h supernatant solution will be treated by a new electrolytic technology. The plant design contemplates a High Density Thickener for the cyanide-free rejects exceeding the backfill demand and a Regrinding Section before the Leaching Circuit. The estimated overall metallurgical recovery sits around 92%. This paper focus on the use of modern technologies to reduce costs, risks, and liabilities.

May 1, 2010