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By E. L. Bruce

Introduction The Outokumpu copper mine is situated in eastern Finland, 50 kilometers west of the city of Joensuu or 225 kilometers directly north of the city of Viborg (Viipuri), which is situated at the eastern end of the gulf of Finland (Figure 1). The ore-body was discovered in 1910 by Dr. Otto Trüstedt after two years of careful, scientifically-directed, search. During the early period of development of the mine, the ore was treated locally and the copper re-covered by an electrolytic process. Now the ore is concentrated by tables and by flotation. The concentrates are shipped to Germany for refining. In 1929 the mine produced 150,000 tons of ore from which between 20,000 and 25,000 tons of flotation concentrates containing 20 per cent copper were produced. Profits in 1929 were approximately half a million dollars, but the present price of copper will affect very seriously the profits for 1930. The ore reserves are given as between 7 and 8 million tons (1). The grade of ore is stated to be 4 percent to 6 percent copper, with a little zinc.

Jan 1, 1931

By G. A. Van Wielingen

"The conditioning of natural gas to meet contract pipeline specifications involves in the majority of cases in Western Canada, the appropriation of substantial capital expenditures for treating and processing installations. It is therefore of vital importance to the owners and producers of natural gas to arrive at an appreciation of the economics pertaining to the production and surface handling of their gas reserves at the earliest possible stage of field development. The treating and processing of natural gas often results in considerable changes in composition and related physical characteristics between the wellhead and the point of delivery of the saleable gas. This paper presents a general outline of engineering calculations which can be applied in the pre-determination of the effects that surface handling of gas will have on the composition and physical characteristics of sale-able gas. Emphasis has been placed on the calculation of hydrocarbon dew-points, heating values and shrinkages prevailing at the various stages in the surface handling of natural gas. It is believed that advance information indicating the approximate ranges of these physical properties will facilitate process selection and will provide a basis for the estimation of capital and operating costs of process installations."

Jan 1, 1960

By D. T. White

"Metallurgical extraction processes often call for the heating of aqueous slurries. Indirect heat exchangers are generally not feasible for service with high yield stress slurries because of low heat transfer rates. It is more appropriate to heat the slurry by direct contact, typically with steam as the heating medium. Although having a long and successful history, direct-contact heat transfer to aqueous slurries has been used without the support of pilot plant research. This paper provides results of the needed research, the work being done at a scale large enough to enable direct scale up to commercial operations. A pilot plant heater was constructed and tested to develop an understanding of the slurry heating process and to ensure that commercial scale heaters were appropriately sized.INTRODUCTIONPressure Leaching OperationsPressure leaching operations are often used to oxidise sulphide gold ores, or for extraction of nickel and cobalt from laterite ores with sulphuric acid. Where there is sufficient sulphur available, the exothermic pressure oxidation reactions can be self sustaining at temperatures as high as 225 ºC, without having to preheat the feed slurry. At lower sulphur levels, slurry preheating is required. This is typically achieved by utilising the flash steam released from the slurry letdown stages and contacting this directly with cold incoming slurry ahead of the autoclave. The vessels where this slurry-steam contact is made are known as heaters or condensers, with the number of pre-heat stages varying, depending on how much heat is evolved in the oxidation reaction (Mason, 1990).In nickel laterite pressure acid leaching processes, which operate between 245 and 270 ºC, the only significant exothermic reactions are those associated with dilution of sulphuric acid in the leach. As a consequence, slurry preheating with flash steam is always used commercially. In practice the number of flash steam preheating stages required varies from 1 to 3, driven by a number of factors, including other uses for flash steam and the upper temperature limit at which preheated slurry can be pumped. A diagram of a typical pressure acid leach train is shown in Figure 1.For pressure acid leaching operations and at low sulphur levels in pressure oxidation, boiler generated direct steam addition to the autoclave is required to sustain the reaction temperature. For this reason it is imperative that the flash steam – slurry heat transfer is efficient and the slurry temperature approaches that of the flash steam closely."

Jan 1, 2012

By R. L. Bruening, N. E. Izatt, S. R. Izatt

The need for selective metal separations has increased as the mining industry encounters more complex ore bodies and demand for higher performance end products expands. The Molecular Recognition Technology (MRT) process uses highly selective SuperLig® resins to remove desired metals from a variety of solutions in the mining and metals processing and recovery industries. MRT separation processes efficiently produce high purity metal products. In this paper, applications of MRT to metal recovery at mg/L to multiple g/L concentration levels are presented and discussed. Specific examples in the precious metal, nickel, cobalt, zinc, copper, and rare earth industries are given.

Jan 1, 2014

By Patrick Chabot

Ce document présente une méthode hybride de long trou favorisant une méthode de minage initiale par chambre-magasin et complétée par une méthode de minage long trou. Cette méthode a été adaptée suite à plusieurs facteurs tels qu?une géologie complexe, une rareté de mineur d?expérience et un haut taux de roulement de main d?oeuvre spécialisée. Cette méthode a permis d'excellents résultats par rapport à la dilution. De plus, la récupération de pilier à haute teneur par forage long trou sera expliquée. Cette méthode permet aussi de récupérer le minerai qui est resté accroché dans les chantiers chambre-magasins. Introduction : La mine Géant Dormant est une mine filonienne d?or située à environ 80km au nord de la ville d?Amos au Québec. Elle est en opération depuis 1988 et à la fin de 2007, elle a produit près de 885 000 onces d?or à partir d?environ 2 400 000 tonnes de minerai pour une teneur moyenne d?environ 11,5g /t Au. Cette mine est la propriété d?IAMGOLD Corporation depuis l?acquisition de Cambior par cette dernière au mois de novembre 2006. Elle emploie 151 employés permanents et environ 41 entrepreneurs.

Feb 1, 2008

By D. V. Dorling, J. T. Bowker, J. A. Gianetto

Over the last few years, interest in the development and construction of large diameter, high pressure pipelines from the Mackenzie Delta in northern Canada and Alaska's North Slope has steadily increased as a result of the projected decline in recoverable natural gas from existing reserves in western Canada. The success of such enormous pipeline projects, which will require utilization of a strain-based design approach, is largely based on successful application of high strength line pipe steels, such as X80 and X100. To fully realize the economic benefits of high strength steels, welding processes and procedures must be developed to ensure that the requirements for high strength and good low temperature toughness are confidently obtainable in field girth welds used in the construction of such pipelines. This study aims to provide a better understanding of the factors that control weld metal strength and toughness for a series of mechanized X100 girth welds produced using a range of narrow-gap gas-metal arc welding procedures. The attainment of high yield strength (> 810 MPa) is considered to be an important target to ensure overmatching strength relative to the longitudinal property distribution of X100 line pipe steel. Some factors that have been considered in this evaluation include influences of gas-metal arc welding process variants (single and multi-wire) and changes in welding procedure specifications, including joint preparation. Key components of this work relate to the reliable measurement of weld metal strength variation through-thickness and as a function of position around the circumference of a given girth weld.

Jan 1, 2005

By L. Sun

A numerical model has been developed to study the air flow in the flow plate and gas diffusion layer assembly on the cathode side of a PEM fuel cell. The flow plate in this type of fuel cell often has serpentine channels and the porous layer is adjacent to the flow plate to diffuse the air to the catalyst layer. Flow cross-over of air through the porous diffusion layer from one part of the channel to another can occur. This flow cross¬over is a result of the pressure differences between different parts of the channel, and it causes the flow rate through the channel to vary with the distance along the channel. A numerical study of pressure distribution and flow cross-over through the gas diffusion layer (GDL) in PEMFC flow field using a serpentine channel system has therefore been undertaken to compare the cases of a single channel and two parallel channels, with the channels having a trapezoidal cross-sectional shape. The purpose of the present work was to study the effect of the flow plate geometry on the basic fluid flow through the plate. The flow here has been assumed to be three-dimensional, steady, incompressible, isothermal and single-phase. The flow through the porous diffusion layer has been described using the Darcy model. The dimensionless governing equations have been solved by using the commercial CFD solver, FIDAP. From the results obtained, it can be found that the single channel systems have greater maximum flow rate difference than the parallel channel systems under the conditions considered in the present study. Also, the size ratio R of trapezoidal cross-sectional shape has a significant effect on the flow cross-over and pressure variation in the flow field.

Jan 1, 2005

By William Petruk

Image analysis studies were performed on mill products from pilot-plant and laboratory tests that had been conducted to determine the effect of grinding media on the selective flotation of two zinc-lead-copper ores. It was found that, when the ores had been ground to the same degree of fineness with flint pebbles, ceramic pebbles or ore fragments (autogenous grinding) as with steel balls, there generally was increased sphalerite, chalcopyrite and galena liberation in the flotation feeds, depending on the textures of the minerals. The increased sphalerite liberation fully accounted for the improved zinc recoveries that were obtained when steel balls were replaced by either pebbles or ore fragments. The increased chalcopyrite and galena liberation accounted for part of the changed technical efficiency of concentration, but other factors, probably changes in oxidation and reduction of iron and in consumption of oxygen, also contributed.

Jan 1, 1977

By J. A. Folinsbee, Andre Robitaille, Tony Y. Chong

"Conventional crushing and grinding is followed by gravity concentration to recover free milling gold. Refractory gold, finely disseminated within the pyrite and arsenopyrite matrix, is recovered by flotation followed by pressure oxidation, cyanidation, and cementation. Non-refractory gold is recovered by cyanidation/CIP processing.A comprehensive test program aimed at improving flotation recovery was initiated in June 1995. Plant testing indicated that flotation tails value could be significantly reduced using mechanical flotation cells. Based on these test results, a flotation circuit that incorporates one of the three existing flotation columns followed by mechanical scavenging and cleaning was developed. Detailed engineering was completed in September 1996. Construction started in February 1997 and was completed in 3 months at a cost of $3.2 million. An on-stream X-ray analyzer was installed to provide real-time arsenic and iron analyses and inferred sulphur value on some of the flotation streams.The new flotation circuit proved to be an instant success. Flotation tails values were reduced by 27%. Final tails solids and solution was reduced from 0.035 to 0 023, and 0.0014 to 0.0006 oz/ton Au, respectively. Based on a mill throughput of 1,620 stpd this decrease in tails value will result in an increased gold production of 7,500 ounces per year. The payback for the project is estimated to be around one year.This paper describes the evolution of the project from bench scale testing to commissioning. Also, the operational and economic impacts on down stream processing are highlighted"

Jan 1, 1998

By K. Poorhaydari, B. M. Patchett, D. G. Ivey

In this paper, some applications of carbon extraction replicas, as samples for transmission electron microscopy (TEM), are discussed. Modern high strength microalloyed (HSMA) steels, used as structural or pipeline materials, have very small grains with substructures. Replicas used in TEM can resolve the grain boundaries and can be used for grain size measurements in cases where the small size of the grains pushes the resolution of conventional optical microscopes. The grain size variations obtained from replicas correlated very well with mechanical property variations, indicated by hardness, in the fine-grained heat-affected zone and base metal of some welded HSMA steels. Replicas are also very suitable samples for precipitate examination with analytical TEM. Advantages and limitations of the application of replicas, as well as some corrections for the estimation of the volume fraction of fine precipitates, are discussed.

Jan 1, 2005

By D. E. M. Plaumann, B. S. Fee, R. D. Hansen, R. R. Klimpel

"This paper briefly summaries the status of a recent program aimed at identifying new chemistry for use as sulfide mineral frothers and collectors. The background motivation and planning behind this work is given along with the general families of chemical structures synthesied and studied in detail followed by typical flotation application results in various laboratory and plant scale tests. Flotation testing to date has been very encouraging with often improved recoveries of certain minerals and improved pyrite selectivity being observed over commercially available reagents. In addition, in some cases, the dosage and lime requirements of these new collectors are significantly less than that associated with standard sulfide mineral collectors. INTRODUCTIONFroth flotation is one of the most widely used and economic means of concentrating metal sulfide ores. There are numerous reference books that have been published on the chemical aspects of flotation [e.g., ref. 1-7] which are based on studying the influence on selected minerals of chemical structures that have been used commercially for many years. In fact, almost 98% of the volume of flotation collector and frother reagents used at the industrial level today were known and manufactured in some form 25 years ago [8]. There are many reasons for this lack of significant new flotation reagent development [9] including the general utility and relative cheapness of existing collectors such as xanthates and existing frothers such as the alcohols and glycol ethers. Another reason is the inherent complexity of the flotation process itself coupled with highly variable and difficult to standardize feed materials. This environment makes reliable reagent comparisons difficult and seriously limits the use of theoretically based chemical structure studies to predict new or optimal reagents. In addition, the higher cost of specialty flotation reagents demands that their performance attributes be significantly greater than that achieved with existing all-purpose commercial reagents - something often difficult to prove in practice."

Jan 1, 1988

The original JKMRC AG/SAG mill model was developed over 30 years ago and has been upgraded a number of times since then, with the current published version being the Variable Rates model that is now over 15 years old. Since this model was developed further enhancements have been derived, some of which are applied in-house and some which have yet to be incorporated. The published and the commercially available model in JKSimMet is currently undergoing a comprehensive overhaul with a vastly extended data base for model evolution and validation. Improvements developed within the AMIRA P9 project, in-house development and a number of collaborative projects, are being incorporated into the upgraded model structure. Enhanced capabilities will include: power-based breakage rates scaling; a far wider mill filling range (from 10% to 40%) that exhibits peak in throughput as mill filling increases; higher ball loads; improved pebble discharge function; improved slurry discharge function incorporating important mill design and operational influences; and the new size dependent breakage function. The model will also be able to accommodate some influence of liner design and multi-component ores (blends of hard and soft components). This upgrade is still a work in progress but substantial changes have been made to date. This paper presents some of the new improvements and their influence on the predictive capability of the model.

Jan 1, 2012

By A. L. Mular

"IntroductionThe mining industry has made slow but steady progress toward the automation of mineral processing plants over the last 35 years. The stimulus to automate is associated with important economic and hidden benefits, so that today, the latest in instrumentation and technology is being employed.This chapter assesses the status of instrumentation justified economically, defines levels of control and certain fundamentals of feedback control loops, describes typical sensors employed in concentrator circuits, summarizes control strategies employed therein, and briefly highlights trends in integrated plant control.Current Status of AutomationAs early as 1948, the mining industry began to show interest in automation, probably because of its close association with the petroleum industry. By 1958, some regulatory control had been achieved in various sections of a concentrator, particularly in crushing circuits. Successes were attributed primarily to the reliability of sensors employed in the corresponding control scheme. By 1961, computers had appeared on the scene, initially, for data logging purposes.From 1958 to 1965, very few new control strategies had been implemented. Guidelines in vogue at this time appeared to be:- Install proven automation, unless a good instrumentation department exists at the concentrator.- Do not bite off too much instrumentation at one time.- Do not purchase on price alone; instrumentation must function in the concentrator environment.- Do not purchase automatic control equipment to be fashionable.Such guidelines were employed1 because of a lack of: (a) quantitative process knowledge, (b) reliable primary sensors, (c) initiative to try something new, (d) trained personnel, and (e) understanding that older concentrators could justify automation in many situations."

Jan 1, 1989

An Atomic Force Microscope (AFM) was used to measure the surface forces between glass sphere and silica plate in CnTAC1 (n=12, 14, 16, 18) solutions. The results showed the presence of long-range attractive forces that can be fitted to single exponential functions. With a given surfactant, the attractive force increased with increasing concentration, and reached a maximum at the point of charge neutralization (p.c.n.). The decrease in the attractive force above the p.c.n. is probably due to the inverse orientation of the surfactant molecules. A plot of the log (p.c.n.) vs. the number of carbons in the hydrocarbon chains of the Cn TACI homologues showed a linear relationship with a slope of -0.37, indicating that the surfactant adsorption entails a decrease in free energy by -0.85 kT per mole of CH2 (or CH3) group. These results suggest that the adsorption of long-chain surfactants is controlled by hydrocarbon chain association during the process of forming surface hemi-micelles (or domains). Possible origins of the long-range attractions are discussed on the basis of the results presented in this communication.

Jan 1, 2006

By K. N. Subramanian

Previously reported work on total oxidative leaching of chalcopyrite concentrates ha s shown that high copper extractions are obtained at 210°C and 0.4 MPa oxygen pressure. A simple integrated flow sheet using pressure leaching, solution treatment involving precipitation with a calcium base, and electrowinning to produce wire-bar-quality copper is described. Reagent and energy requirements developed from this work indicate that the process could be attractive for small operations where a smelting-refining complex cannot be justified.

Jan 1, 1978

By F. McCarthy, W. Zhang, R. McDonald

"The processing of nickel laterites has been a topic of major interest at CSIRO for almost twenty years. During this period CSIRO has collaborated with other researchers and industry in developing a better understanding of existing processes and been actively involved in testing/developing new beneficiation and process options for these ores. The current paper summarises the results of selected studies and highlights improvements that have been achieved. Key topics to be discussed include enhancements in the mineralogical characterisation, beneficiation approaches, improvements in the understanding and application of leaching technologies, the development of synergistic solvent extraction (SSX) for the recovery of nickel/cobalt from laterite leach liquors and the collaborative development of the Direct Nickel process. Future opportunities and key research questions will be briefly examined.INTRODUCTION Nickel laterite ores comprise a significant resource in Australia and according to United States Geological Survey data nearly a quarter of world reserves are located there (USGS, 2016). More specifically, around 95% of Australian nickel resources (laterite and sulfide) are located in Western Australia (Australian Government, 2017). Given the recent closure of Queensland Nickel, essentially all of Australian nickel production occurs in Western Australia and the primary producers of processed nickel products include Nickel West (Kwinana) with ~84,000 t saleable nickel metal in 2016 (BHP Billiton, 2017), Minara Resources (Murrin Murrin) with 46,700 t nickel metal produced in 2015 (Glencore Australia, 2017), and First Quantum Minerals Ltd (Ravensthorpe) who sold 25,882 t nickel as mixed hydroxide product in 2016 (First Quantum Minerals, 2017). The total sales of nickel from Western Australia in the 2015-16 financial year were 175,722 t. The study of nickel laterites at CSIRO recommenced at the time second generation High Pressure Acid Leaching (HPAL) plants were being commissioned at Bulong, Cawse and Murrin Murrin in the late 1990’s. A combination of technical and engineering issues meant that the ramp-up times at these operations were slower than expected and the outcomes resulting from the attendant problems are well documented (e.g. Griffin & Becker, 2000; Reid & Barnett, 2002; O’Callaghan, 2003) while the issues faced at the BHP-Billiton-built Ravensthorpe plant have been addressed by the current owners of this project, First Quantum Minerals Ltd (Piper, 2012)."

Jan 1, 2017

By C. Anderson, H. Huang, P. Miranda, E. Dahlgren, I. Chandra, M. Jeffrey

The latter part of the 20th century saw great advances in the treatment of refractory gold ores coupled with increased reliance on the use of cyanide for gold processing. Now, in many parts of the world, there is social pressure to limit or eliminate the use of cyanide. As well, treatment of some refractory ores or concentrates which have excessive cyanide consumption, gold cyanide pregrobbing or significant sulfide content remain difficult. This paper will outline the history of the development of alkaline sulfide leaching as an ancillary process to nitrogen species catalyzed (NSC) pressure leaching. Electrochemical fundamentals and the applicable thermodynamics of the alkaline sulfide hydrometallurgical system will be outlined. As well, examples of refractory gold recovery with alkaline sulfide hydrometallurgy such as an arsenopyrite gold concentrate application, a chalcopyrite gold concentrate application, a pregrobbing gold ore application, and a cyanide consuming gold ore application will be delineated in this paper.

Jan 1, 2005

By R. D. Livingstone

"THE LETHBRIDGE COAL FIELD lies mainly .to the north and west of the city of Lethbridge. Mining carried on in this area for over eighty years until 1965. Before the building of a railway the coal was carried by bullock wagon to Montana for use in smelting, and for a while by river boat to Medicine Hat for railway use. The single, almost flat, worked seam is designated the ""Galt"" seam and is about 1.5 metres thick. It belongs to the Belly River formation and is under cover of 80 to 180 metres of weakly stratified sediments. A complex system of cross faults adds to the mining difficulties. Close timbering required in the entries and rooms reflected in a high timber cost and lower output per man shift. The coal is High Volatile"" C"" bituminous in rank with maximum gross calorific value of 11,200 Btu per pound and with a well defined cleavage. Roof conditions in the field range from very tender and very heavy on the south end of the field and west of the Oldman River to a more stable character to the north. Relatively speaking, the whole field would earn a rather tender rating and definitely so in relation to many U.S. fields. Floor conditions are characterized by a bentonitic type heaving in the south end of the field west of the Oldman river to a more stable situation in the north, which can tolerate shuttle car operation if kept drained. Water problems are minimal, except paralleling the Oldman River, where the seam dips below the river level. While vigilance is necessary to prevent accumulations of gas, the volume is rather limited. The seam was entered by shafts, except where small mines were located along the Oldman river banks and gained access by drifts. The coal seam was developed by driving either 3 or 4 Face entries 2 1/2 metres (8 ft) wide on 18-metre ( 60-ft) centres. Sets of dual butt entries driven at right angles to the Face entries completed development work. Normally rooms up to 8 metres wide were turned off the butt entries on up to 11 - metre centres. These were worked in groups of three to five, depending on the roof conditions, and normally advanced 60 m (200 ft). In some areas rooms had to be abandoned short of their objectives due to roof pressure, heaving floor and intermittent work."

Jan 1, 1985

By W. G. Miller, J. D. Scott, D. C. Sego

ABSTRACT: As part of an overall study of properties and processes influencing consolidation of oil sands fine tailings resulting from different extraction processes, self-weight consolidation tests were per-formed. Fourteen 2 m and 1 m high standpipe tests were instrumented to monitor the rate and magnitude of consolidation of seven fine tailings materials. Tests provided valuable information about the variation of consolidation related to differences in fine tailings material properties that result from a change in bitu-men extraction process (caustic versus non-caustic). In addition, the effect of adding a coagulant to caustic fine tailings was measured. Test results are presented and discussed in terms of consolidation rate long-term volume decrease, compressibility, and downward drainage. Non-caustic fine tailings had fasterinitial consolidation, which is important in tailings ponds for reducing storage capacity and returning decant water at a faster rate to the extraction plant. Similar results were obtained for caustic fine tailings with a coagulant addition. However, long-term settlement of the different fine tailings appears to con-verge to a similar value over time because it is then governed by effective stress.

Jan 1, 2011

By T. C. Cheng, G. P. Demopoulos

It is the object of this paper to discuss various options for improving the hematite process in terms of increased throughput hence lower capital cost and production of saleable quality hematite. With reference to increasing the throughput of the process, it has now been determined via the analysis of Akita Zinc Co's continuous industrial autoclave performance data that the process kinetics is limited by the rate of the hydrolytic precipitation reaction. By correlating the hydrolytic precipitation rate to supersaturation ratio, it is shown that accelerated kinetics can be achieved via the following measures: (1) in-situ neutralization with addition of zinc calcine; (2) elevation of temperature; and (3) dilution of feed; of which, the first one was retained for further evaluation. According to presented estimates, addition of calcine, amounting to only 2.6% of the total zinc calcine processed, can allow for shortening the retention time by at least 50%. Such drastic shortening of retention time may be either used to increase the throughput of a given autoclave circuit or alternatively to release autoclave capacity for clean hematite production. Hydrothermal treatment of the crude hematite product proved effective in producing clean hematite as according to laboratory tests, hence allowing the sulphur content of hematite to be reduced from around 4% to less than 1%. A conceptual flowsheet incorporating in-situ neutralization for accelerated kinetics with hydrothermal upgrading of crude hematite without sacrificing production capacity and with minimum upset of the plant's water balance is described.

Jan 1, 2004