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By Warnett Kennedy

"GENUINE CONCERN for the environment is a built-in attitude of mind. If you do not have it by age 40 you probably never will. Some people speak the jargon of 'environment' and 'ecology' for political reasons, others because it feeds their need and bias toward attitudes of moral indignation or dissent. Others pay lip-service for purely business reasons. Complete reactionaries equate conservationists, ecologists and environmentalists as either 'commies' or 'pinkos'. Their real credo is the old saying, ""Where there's muck there's brass."" Those who have genuine concern for good environment are not only romantics like Thoreau but realists who sense the danger to our planet if human greed is rampant and unchallenged. The cities are in real trouble. Almost 75 per cent of the population already live in and around cities. Even mining men live in cities or bring up their children in the new 'instant' towns. The ecology of cities is the concern of all. Our distinguished guest Stewart Udall, in his book ""The-Quiet Crisis,"" quoted Thoreau in 1859 as having written ""each town should have a miniature wilderness park, a primitive forest of five hundred or a thousand acres where a stick should never be cut for fuel, a common possession forever."" Mr. Udall will be glad to know that this advice was taken in at least one instance known to me. I refer to Stanley Park in Vancouver. It is a primitive forest of 1000 acres right inside our small downtown peninsula. It remains unmanicured. This month we celebrated the completion of a seawall of 4%, miles along its perimeter. The construction of this wonderful walkway started in 1910. We are very, very proud of our park."

Jan 1, 1972

By G. Wilson

"Satisfactory hydraulic performance of a centrifugal slurry pump is not the only design criterion. If abrasive wear exists the severity of any damage can be reduced and the life of the wearing parts prolonged by selecting the correct pump to suit the conditions of service. This paper is concerned with the design and construction of centrifugal pumps for handling abrasive solids. The wear phenomena due to the slurry being pumped and the materials used to combat abrasive, wear are outlined. The hydraulic design of the impeller and casing and their relationship to wear and the hydraulic radial and axial unbalance are discussed. The prediction of abrasive wear in pumps can not be precise, as many factors are involved - and this is the object of current research."

Jan 1, 1973

By K. M. Mayhew, G. D. Barr, T. M. McCoy, C. T. Knilans

"Teck Resources Limited (“Teck”) has developed and extensively tested on a continuous basis the CESL Technology hydrometallurgical process for treating copper and nickel sulphide concentrates, including bulk copper-nickel concentrates. Copper, nickel and cobalt are leached efficiently into solution, utilizing CESL process conditions. Total precious metals including gold, silver, platinum and palladium are recovered from the residue stream via sulphur flotation. This paper describes the CESL Technology testwork on a bulk copper-nickel concentrate derived from Twin Metals Minnesota?s (TMM) deposits within the Duluth complex and evaluates the economic benefits (increased cash flow, increased revenue certainty) and investment criteria (capital cost, payback and cash flow) of incorporating CESL Technology into the staged development of TMM?s deposits.INTRODUCTION Mineral Processing and the Role of Hydromet in the Duluth Complex The Duluth Complex in northern Minnesota, United States (US), represents one of the largest undeveloped accumulations of copper, nickel, gold, and platinum group metals (PGMs) in the world, ranking second in copper and PMs and third in accumulation of nickel. The figure below identifies some of the larger known deposits within the Complex (see Figure 1). Copper, nickel, PM and PGM mineralization within the Duluth Complex is hosted by mafic to ultramafic intrusive rocks that are part of the overall intrusive complex.One of the mineral processing challenges of Cu-Ni-PM-PGM deposits in this Complex is the complicated, polymetallic nature of the mineralization1: copper occurs primarily as chalcopyrite and cubanite with minor occurrence of talnakhite; nickel occurs as pentlandite and refractory nickel oxide/silicates; iron sulphides are present as both pyrrhotite and troilite; and PMs/PGMs occur in both the sulphide matrix as well as discrete minerals. An additional challenge for the Duluth Complex is the ratio between copper and nickel; in most of the identified deposits, copper grade is three to four times greater than the nickel grade, which precludes the production of a simple bulk concentrate due to the lack of a traditional smelting market for a bulk concentrate of this character."

Jan 1, 2017

By H. Ikeman

"The highly specialized communication systems used in the mining industry place exacting demands on equipment and transmission media. Safely and reliability of services are perhaps the two most important factors. Fibre optics is ideally suited 10 meet these stringent requirements. Aside from being an intrinsically safe, non-sparking and EMI/RFI immune medium , fibre optics offers greater reliability , higher quality of services and superior flexibility over conventional copper or radio-based communication systems.This paper wilt show how fibre optics can be applied in mining industry applications. Emerging trends and concepts will be presented to show how fibre-optic-based integrated service communication networks and local distribution systems can be implemented.IntroductionCommunication requirements in today's mine s are varied and extensive. The communication system must be rugged , safe and reliable, yet provide an ever increasing amount of high quality services. Presently, these systems are implemented using conventional copper cable. As mining method s and technology advance and the demand for better and more communication services increases, traditional systems quickly reach their limitations. It is under these circumstances that we turn to fibre optic communication systems.Fibre optics is a mature technology which is finding its way into more and more applications worldwide. A fibre optic communication system can provide a level of performance unattainable by conventional cable systems yet ca n be cost competitive. As is well known, fibre optics provides a noise-free, noise-immune, high -capacity communications channel. Glass fibre, being dielectric and non-sparking, is an intrinsically safe communications medium. Clearly, it is ideally suited to the harsh environment present in a mine.From a communication systems point-of-view, the topology of a deep mine is unique. The objective of the systems engineer is to implement a total communications capability throughout this wide spread area. Ideally all classes of services should be accessible throughout the network-an integrated network concept. Recent advances in communications technology combined with fibre optics make this realizable."

Jan 1, 1984

By J. R. Pronovost, P. M. Tiley, D. W. Watts

"In 1980, J.S. Redpath Limited were retained by Dickenson Mines Limited to increase hoisting capacity from 700 to 1000 tons per day. The hoisting capacity of the present skip-over-cage system could not be increased significantly through design modifications. The other constraint was a minimum of disruption to the current production. The Dickenson shaft was a three-compartment shaft from surface to the 8th level and four compartments before the 8th to the 23rd level. The solution to the problem was to remove the services from the shaft man-way compartment from the 8th level to surf ace by drilling a borehole close to the shaft and rerouting those services through the borehole to the 8th level. A service compartment would then be available from surf ace to the 23rd level.By providing a service hoist in this compartment, the skip hoist would then be free to produce the 1000-tons/day required production. This paper will describe the search for the required hoist and the friction hoist selected for the project, and trace the design modifications required to modify the hoist to suit the Dickenson application and satisfy the Department of Labour safety requirements.The paper has been co-authored by J.S. Redpath Limited and C.L. Tiley Associates, who participated in the design changes and eventual commissioning of the hoist.IntroductionIn the earl y part of 1980, J.S. Redpath Limited conducted an engineering study on the Dickenson Mines Limited No. 1 Shaft materials handling system. The object of the engineering study was to investigate the possibility of increasing the tonnage hoisted from the No. 1 Shaft complex by adding a service cage compartment and service hoist. This would permit utilization of the existing hoisting plant solely for production hoi sting. A further consideration of the engineering study was that any alterations had to be accomplished with little, or no, interruption to production."

Jan 1, 1982

By J. R. Pronovost, P. M. Tiley, D. W. Watts

"In 1980, J.S. Redpath Limited were retained by Dickenson Mines Limited to increase hoisting capacity from 700 to 1000 tons per day. The hoisting capacity of the present skip-over-cage system could not be increased significantly through design modifications. The other constraint was a minimum of disruption to the current production. The Dickenson shaft was a three-compartment shaft from surface to the 8th level and four compartments before the 8th to the 23rd level. The solution to the problem was to remove the services from the shaft man-way compartment from the 8th level to surf ace by drilling a borehole close to the shaft and rerouting those services through the borehole to the 8th level. A service compartment would then be available from surf ace to the 23rd level.By providing a service hoist in this compartment, the skip hoist would then be free to produce the 1000-tons/day required production. This paper will describe the search for the required hoist and the friction hoist selected for the project, and trace the design modifications required to modify the hoist to suit the Dickenson application and satisfy the Department of Labour safety requirements.The paper has been co-authored by J.S. Redpath Limited and C.L. Tiley Associates, who participated in the design changes and eventual commissioning of the hoist.IntroductionIn the earl y part of 1980, J.S. Redpath Limited conducted an engineering study on the Dickenson Mines Limited No. 1 Shaft materials handling system. The object of the engineering study was to investigate the possibility of increasing the tonnage hoisted from the No. 1 Shaft complex by adding a service cage compartment and service hoist. This would permit utilization of the existing hoisting plant solely for production hoi sting. A further consideration of the engineering study was that any alterations had to be accomplished with little, or no, interruption to production."

Jan 1, 1982

By C. J. Cajka

Commodity agreements, trade liberalization, producer cartels, the New International Economic Order, price stabilization and access to supply are buzz words of the day. The international concern and dialogue on these concepts, often by a new breed of politically motivated experts, have generated intense interest in seeking an international solution to natural resource problems. While this momentum was maintained during the past year, the growing incidence of protectionist actions by several major nations has been eroding confidence in the global approach. The seriousness of current difficulties has created an urgent need for decisive action. At the same time, the limitations of the global approach have become more evident.

Jan 1, 1978

By J. P. Messervey

THE story of the efforts made by the Department of Mines of Nova Scotia in the search for and investigation of mineral resources for the Canadian war effort began in the spring of 1937. During the past five years, however, heavy enlistments in the Active Service Forces by employees of the mining industry of the Province caused a recession in the production of coal, salt, and other essential minerals required to keep industry rolling on a wartime basis. A marked increase was shown during the period in prospecting for 'strategic' minerals, not only by individuals but also by some of the foremost mining companies. The Provincial Government offered encouragement in this field of endeavour by the enactment of legislation whereby the prospector was enabled to secure the maximum area of ground in a prospecting license at a minimum of cost. The labour requirements on the ground staked, however, remained unchanged. The Nova Scotia Department of Mines continued active investigation of minerals vital to the war effort. These included fluorspar, barytes, diatomite, limestone, and coal. Fundamental knowledge concerning the geology and mode of occurrence of these minerals was accumulated and extensive diamond drilling was carried out on the promising occurrences. Work in these fields is being continued.

Jan 1, 1945

The Curtin University Gold Technology Group has been involved in surveying, modelling and optimisation of batch centrifugal concentrator type gravity circuits and CIP/CIL circuits for nearly two decades. The most commonly asked question regarding gravity recovery is, “What is the benefit of a gravity circuit”, which can be hard, if not impossible, to quantify. With the help of the AMIRA P420 Project’s Integrated Liberation Leach Model (ILLM) it is now possible to evaluate the effect of gravity recovery on total gold recovery when changes are made to the grind size, gravity and/or leach/adsorption circuits. This paper demonstrates how the ILLM can be used to determine the net benefit of introducing or modifying a gravity circuit and assess the effect of operating conditions (grind size, coarse gold size distribution, leach residence time, carbon activity, etc.) on plant performance.

Jan 1, 2017

By John Shirokoff, Ladan Khaksar

"Cyclic polarization technique and also potentiodynamic measurements were applied to study corrosion behavior of 13% chromium steels in chloride containing environment. Potentiodynamic measurements were performed at 25 and 75 °C with 0, 10 and 20 g/l NaCl in 0.01 M hydrochloric acid solution. At the same time, the significant pitting parameters such as corrosion potential (Ecorr), pitting potential (Epit), protection potential (Epro) and passive current (Ipass) of cyclic polarization curves with various NaCl concentration were analyzed and compared to describe the corrosion behavior of 13% chromium stainless steel. Surface measurement techniques such as SEM and EDS were used for morphology and analysis of corrosion products. The results showed that both temperature and Cl- concentration had significant effects on corrosion behavior of 13% chromium stainless steel in acidic solution.INTRODUCTION Of all the corrosion resistant alloys (CRA) used in oil and gas developments, martensitic stainless steels (MSS) are some of the most common ones these days. These steels not only have the advantages of normal steels: high strength, cost-effective, easy to manufacture, available in a wide variety of product forms, but they also have good CO2 corrosion resistance at higher temperatures as a result of their 11% minimum chromium content. One of the most common types of MSS used in the oil and gas industry is 13% chromium steel. NACE and API standards both reference several different varieties of 13% chromium steels for use in oil and gas projects(“Corrosion Resistant High Cr Steel for Oil and Gas Wells,” 2013). All types of 13% chromium steels have about 12 to 14% chromium and other minor alloying additions, and can be placed into two general groups: conventional and modified. Conventional 13% Cr steels (13Cr) are those most common in oil and gas, some of which are CA6NM (UNS J91150), AISI 410(UNS S41000), and AISI 420 (UNS S42000). These alloys have excellent corrosion resistance when compared to carbon steels up to about 300°F (150°C) and are used for a variety of wellhead, tubular, and downhole components however they have very limited resistance to cracking in H2S (Vallourec Group, 2015). Modified 13% Cr (M13Cr) steels came from the need for increased corrosion resistance at higher temperatures, increased H2S cracking resistance, and increased yield strength above 85 ksi (586 Mpa) primarily for tubular goods and other downhole equipment. These features were developed by taking a conventional 13Cr steel and adding nickel (Ni), molybdenum (Mo), copper (Cu), and other alloying elements. M13Cr provides better corrosion resistance than 13Cr up to about 350°F (177°C), yield strengths up to 110 ksi (758 Mpa), and also improved H2S cracking resistance(“Corrosion Resistant High Cr Steel for Oil and Gas Wells,” 2013)."

Jan 1, 2017

By J. Worden, D. Hughes, S. Smart, H. Zughbi

The enterprise wide optimization (EWO) of steelmaking and manufacturing is a multi-level, hierarchical problem which spans higher level corporate planning and scheduling through to the lower level operations of processes that produce and manufacture steel. External and internal system dynamics combined with process unit co-ordination create complex changing circumstances for the enterprise. This paper presents a scoping study as a prelude to enterprise wide considerations at an integrated steelworks to help inform the choice of appropriate model types and optimization techniques. The hierarchical, multi-level structure of the enterprise and the important spatial-temporal scales to consider are defined. Insights into the system were gained by analyzing a large set of dynamic operational data. Over two years of data were subject to both univariate and multivariate analysis with the intent of understanding the complex interrelations of energy flows on site, the inherent system dynamics of the energy network, system operational modes, aspects of planning and scheduling and the coordination between major processing units. This analysis was further used to evaluate the performance of the system in regards to energy utilization and understand the potential economic benefits derived from improved operational decisions.

Jan 1, 2015

By J. Zhou1

"The extractive metallurgy of gold ores is largely driven by their grade and mineralogy. The concentration of gold in the crust is extremely low and highly variable, resulting ore variability in many gold and copper-gold deposits. More importantly, gold in an ore may occur in two or three forms (i.e. microscopic gold, submicroscopic gold and surface gold), making gold ore processing extremely challenging. Geometallurgy is a technique to document variability within an orebody and quantify and evaluate the impact of many factors including geology and mineralogy on grinding, flotation, leaching and metal recovery processes. The objective of gold geometallurgy is to reduce and minimize the technical risk in project evaluation, plant design, mine planning and production forecasting through geometallurgical modelling, representative sampling and subsequent systematic mineralogical and metallurgical testwork. Gold deportment study is a powerful tool in characterization of various gold ores. Effective and quantitative gold deportment results are critical and useful for predicting gold recovery and building geometallurgical models of gold ores. This paper provides an overview of geometallurgy fundamentals and applications in gold processing, with a focus being on the ore characterization and gold deportment study.INTRODUCTION Geometallurgy is an inter-disciplinary approach which links the geological, geochemical and mineralogical characteristics to the metallurgical performance of an orebody. Combined with mine planning, it has been used in scoping, prefeasibility and feasibility studies, process design and optimization of gold, copper-gold, copper-moly, nickel and iron projects among others (Williams & Richardson, 2004; Dobby, Bennett, Bulled, & Kosick, 2004; Bulled, 2007; Bulled, Leriche, Blake, Thompson, & Wilkie, 2009; Kormos, Sliwinski, Oliveira, & Hill, 2013; Muinonen, Sciortino, Korczak, & St-Jean, 2013; Leichliter & Larson, 2013; Leichliter, Jahoda, & Montoya, 2013; Hatton & Hatfield, 2013; Baumgartner et al., 2011, 2013; Hoal, Woodhead, & Smith, 2013; Zhou, 2013). The goal of a gold or copper-gold geometallurgical program is to characterize and understand the metallurgical variability of an orebody, such as comminution, gravity, flotation and cyanidation parameters and metal recoveries, and to build a geomet model which can be used to assist in mine planning and to predict the plant performance. In any geometallurgical program, representative sampling is the key to ensure the results of a geometallurgical study will reflect future performance once the plant is commissioned. Geometallurgy compliments, but does not replace, the traditional mineralogical and metallurgical approach during the development and operation of a gold or copper-gold project. Geometallurgy is a methodology for testwork design and a framework for mine planning. The first part of this paper provides an overview of geometallurgy fundamentals and application in gold ore processing."

Jan 1, 2017

By Robert Halupka

The industrial minerals sector represents a broad range of products involving a variety of technologies serving a diversity of markets and end uses. Unit values of products vary widely, reflecting the peculiarities of each product/market sector. Generalizations are therefore understandably difficult to make and borrowers may need to take extra time to "educate" lenders on the key aspects of their business and industry sub-sector. This paper will examine the factors and the thinking that lenders apply when considering financing proposals to companies in the industrial minerals sector. If you understand the lender's perspective and their concerns, then you can make better use of your own time and resources when arranging financing for your company or project.

Jan 1, 2001

By Yutaro Fukase

Various types of service robots have recently been developed for guarding facilities, caring for the elderly, carrying objects, and cleaning buildings. As barrier-free facilities improve and their use expands, these robots have more space within which to move inside buildings. Yet robots that move autonomously rely on position-detection systems. Though improving rapidly, these systems are far from perfect in determining positions in certain situations, especially when robots navigate large areas or cross various locations. Our group is working to solve this problem by developing a position-detection system using random-dot patterns on a floor. First, we construct a floor with a random-dot pattern and register the positions of all of the dots into a database. As the robot moves across the floor, a camera on the robot captures an image of the floor beneath it and crops the dot pattern in the image. The cropped dot pattern is matched to the dot patterns in the database to determine the position of the robot and the direction in which the robot is facing or moving. In this paper we propose a self-localization system and matching algorithms derived from a space technology and present the results of several experiments.

Aug 1, 2013

By P. West-Sells, B. Wassink, N. Fisher

Gold leaching from a commercial cyanide-amenable gold ore was studied at 25°C using sodium bisulfide-hydrogen sulfide solutions containing elemental sulfur. Gold extraction from the ore using 0.55 M NaSH, 4.1 atm (60 PSI) H2S, 1 g/L S8 and 26% solids by weight was about as good as the best extraction obtained by cyanidation. Maximum extraction was achieved in roughly 48 hours. Sulfur dissolves in the bisulfide solutions to form a mixture of polysulfides. Simple speciation calculations indicate that gold solubility as bisulfide complexes should be roughly ten times higher than in the absence of added zerovalent sulfur. The principal bisulfide complex is believed to be [Au(HS)2]-. Gold dissolution is favoured by increasing HS- concentration and by increasing H25 pressure. Polysulfide complexes of gold are also likely to be formed, and may contribute substantially to gold leaching. Two experiments using pure gold were also performed. Up to 100 mg/L gold was dissolved in 140 hours using 0.55 M NaSH, 1 g/L added elemental sulfur and 6.2 atm H2S.

Jan 1, 2005

By H. Kolcz, G. S. Dobby, R. Stratton-Crawley, S. W. Wilson

"The Matte Separation plant at Inco's Copper Cliff Smelter Complex is described. The continuing implementation of flotation column technology in the flowsheet in various applications is reviewed. Comparative studies on 0.038, 0.10, 1.1 and 1.8 m diameter columns have been carried out. It was demonstrated that consistent metallurgical performance was obtained with both pilot- and plant-scale units. Grade-recovery relationships for plant columns can be predicted with confidence from data obtained from test equipment. The work indicates further areas of the flowsheet in which columns present an attractive alternative to conventional cells. INCO’s MATTE SEPARATION PROCESSNickel concentrate from Inco’s Sudbury area mills has been processed in the Copper Cliff smelter for sixty years. Prior to that, Sudbury ores had been smelted directly. Historically, copper-nickel separation from smelter converter matte was achieved by the classical Orford process. In the mid-1940s Inco developed an improved separation scheme based on mineral processing methods, the Matte Separation Process. A generalized Copper Cliff Smelter Complex flowsheet is shown in Figure 1.Iron sulfide and gangue contained in the nickel concentrate are rejected in the smelting-converting process. The molten product, typically containing 50% Ni, 25% CU and 22% s, is cast at about 1000 ºC, into floor moulds and allowed to slowly cool for four days. During this period nickel sulfide (heazlewoodite, Ni,S,), copper sulfide (chalcocite, cu,S) and a copper-nickel metallic alloy precipitate and form a coarse grain structure that is amenable to separation by physical means. The phase chemistry of this system has been described previously by Sproule et al (1). This matte then becomes the feed to the Matte Separation Process.A simplified block flowsheet of the Matte Separation Process is shown in Figure 2. Matte ingots, typically weighing 20 tonnes each, are broken and crushed in a three stage crushing plant to approximately minus 0.01 m and conveyed to the Matte Separation building. Grinding is carried out in two parallel circuits each consisting of a rod and ball mill in series producing a flotation feed which is 65% minus 44 microns. Typical throughput of each grinding circuit is 650 tonnes/day. The metallic fraction of the feed is recovered by magnetic separation. This product, containing about 66% Ni and 15% CU, is a major component of the feed to the Copper Cliff Nickel Refinery."

Jan 1, 1990

By S. Homulos

"Introductory and GeneralTHE Northwest Territories comprise all that region -of Canada lying between Yukon Territory and Hudson bay and north of the 60th parallel of latitude. For purposes of mine .administration the Territories are divided into three districts: Yellowknife, McKenzie, and Arctic and Hudson Bay. Mining recording offices for the respective districts are maintained at Yellowknife, Fort Smith, and Ottawa. The mine inspection for the entire area, and also for Yukon Territory, comes under the Federal Department of Resources and Development. Two mining inspectors are responsible for these inspections: the Chief Inspector of Mines, with headquarters in Ottawa, who makes trips into the north at least twice a year, and a Resident Inspector, stationed in Yellowknife.The Resident Inspector is constantly making inspections of active properties. This involves a considerable amount of air travel as the region is large and properties are widely scattered.Although there has been prospecting and staking of claims in each of the three districts of the Northwest Territories, actual mining has been conducted only in the Yellowknife district, and for purposes of this paper we are solely concerned with that district."

Jan 1, 1952

By R. B. Nourse, S. F. Gwynn-Jones, S. Nikolic, M. L. Bakker, I. McDougall, H. Joubert

"Tenova Pyromet’s core furnace knowhow and expertise has been built within the ferroalloy and nickel/platinum group metal (PGM) industries with the supply of electric furnaces for a number of nickel/PGM operators, including Eastplats, Lonmin, and Anglo-Platinum in South Africa, Mineraçào Serra Da Fortaleza in Brazil, and Norilsk Nickel in Russia. Tenova Pyromet has also supplied the electrode columns and associated electrode equipment – the heart of the electric furnace technology – for cobalt recovery in furnaces in Zambia and the Democratic Republic of the Congo. The quantity and size of projects undertaken by Tenova Pyromet has provided the opportunity to continuously improve furnace designs and the scope of supply, culminating in the most recent nickel/PGM project currently under construction at Northam Platinum. Through this innovative culture, the Tenova Pyromet Base Metals Initiative was formed in 2015 to develop the Novasmelt™ Furnace; a next generation optimised Top Submerged Lance (TSL) furnace design. The combination of Tenova Pyromet’s advanced Novasmelt™ product with our industry leading electric furnace technology are discussed with reference to applications for nickel and cobalt production. Flowsheet arrangements are compared summarising potential capital savings, operating requirements and achievement of downstream product quality.INTRODUCTION Tenova Pyromet is a leading player in the field of smelting technology development and equipment supply. Tenova Pyromet is the result of the union of three furnace suppliers under the Tenova banner: Techint Technologies (Tagliaferri), Core Furnace Systems Corp (Lectromelt) and Pyromet Technologies. The furnace experience of the combined groups dates back over a century with the earliest Lectromelt going into production in the early 1900s. Throughout the modern era, Tenova Pyromet has developed a reputation for providing dependable innovative smelting technology, high quality equipment and sound project execution to a worldwide client base with customer plants operating in Europe, Southern Africa, North America, South America, Russia, Kazakhstan, the Middle East, South Korea, and India. Tenova Pyromet’s core knowledge and expertise was developed in the South African ferroalloy, base metals, and platinum group metals (PGM) smelting industries. Tenova Pyromet has spent considerable effort on development and has contributed significantly to improve the state of the smelting industry. Tenova Pyromet’s electrode columns have become widely renowned and are now providing significant benefits, especially in increased furnace availability, to many smelting furnace operators. The electrode column is the heart of the furnace as it delivers a controlled amount of electrical energy, at an optimum depth in the burden/bath, to the smelting process. Every furnace is custom designed to the specific operating range and optimal operating point of that furnace and process"

Jan 1, 2017

By J. M. Bowen, P. Wemyss

"Gold losses to natural carbonaceous matter during cyanide leaching have been investigated for over a century. The variation in the severity of the problem from one ore to another has led to a range of different processes being implemented at different mine sites. Most commercial options utilise one or more of the following processes: roasting, carbon pre-flotation, organic blinding, CIL, chlorine passivation, pressure oxidation, biological passivation, elevated temperature CIL, RIL and thiosulfate. This paper provides a background to identify the most appropriate process or combination of processes for a particular ore. It also presents information on how these processes may be implemented, drawing on information in the literature and from current or recent applications at operations such as the following: Stawell, Kumtor, Penjom, Twin Creeks, Macraes Flat, Kittilä, Fosterville, Inata, Carlin, Goldstrike, and Jerritt Canyon. Various process options have been dismissed, or deemed unsuccessful due to limited knowledge available on the strengths and weaknesses of the different options and their implementation. The authors have collectively been involved in flowsheet development and project implementation in four commercial plants that have treated preg-robbing ores.INTRODUCTION Cyanide processing has been the mainstay of gold recovery for well over a century. It is generally a very effective process with over 90% recovery on free milling ores, but complex and refractory ores may only give 0–50% recovery with conventional processing (La Brooy et al., 1994). People have written about gold losses to natural carbonaceous matter during cyanidation for over a century e.g. Feldtmann, (1915). The earliest reports related to African operations, but the issue has since been reported in Canada, North and South America, Australia, Russia and China. The phenomenon is usually referred to as ‘preg-robbing’ dating from the times before the use of granular activated carbon for gold recovery, when gold was lost from the pregnant solution before it could be separated from the leach solids and recovered by cementation. Many excellent reviews have been published e.g. Dunn et al. (2013), summarising the options considered and where they have been applied commercially."

Jan 1, 2017

By H. Oterdoom, S. Pilger, T. P. Bui, J. Rotarius

"Most FeNi furnaces used to rely on post-combustion and off-gas cooling inside the furnace to eliminate the produced CO gas, and control the off gas temperature. As furnace load, capacity, and thus gas volumes increased over the years, this led to increased instabilities that can cause problems in controlling the operation. Some of the large capacity furnaces nowadays work with partial or full combustion outside the furnace, more similar to the steel industry. Forced combustion with or without enriched air and other additions can support in controlling post-combustion, stabilizing and even reducing off gas amounts, and affecting composition. This paper presents some of the possibilities and advantages of having a specially designed post-combustion system for the FeNi laterite industry, but that could also be applied to other processes as well.Large Scale Furnaces In the FeNi industry, the Rotary Kiln Electric Furnace (RKEF) process is still going strong in spite of continuous hope that hydrometallurgical processes will one day make the RKEF plant obsolete. Within the pyrometallurgical plants there is a continuous trend for larger scale furnaces. The development for a number of furnaces that were started before 1985 and increased capacity by “natural growth” is given in Figure 1. Natural growth refers to the development of the plants that after having mastered a certain level of operation, were ready for a higher load that could be installed either with a new furnace on the same site, or during a revamp. The advantages of natural growth are numerous, for example: •,Deep knowledge of the ore and its’ behavior, no need for testing, and little risk of surprises. •,Mining, laboratory, equipment, etc. is all proven technology for the conditions on site. •,Starting a furnace with increased capacity is a re-start, not a green-field commissioning. •,Typically, when increasing the production capacity of an existing plant, not the entire plant is commissioned for the first time, but only a part. In the FeNi laterite industry for example, the kilns may already have had the capacity to provide enough material."

Jan 1, 2017