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By R. Phillips, A. G. Doll, D. J. Barratt

"The Bond low energy impact (crushing) work index test is specified to be performed on rock specimens between 50 mm and 75 mm in effective diameter. NQ-diameter drill core, frequently used in mineral exploration programs does not meet that specification, it being 45 mm diameter or less.This paper reports the effect of performing the impact test on contiguous sections of HQ diameter and NQ diameter core, exploring the hypothesis that the contiguous intervals give equivalent results in spite of the core diameter difference."

Jan 1, 2012

By G. Dubé, A. Leclerc, P. Quinn, G. E. Agar, J. Y. Clouthiér, J. D. McLaughlin

"Gold dissolution by cyanide requires the presence of oxygen which is usually supplied by sparging compressed air into the gold containing slurry. For those ores that contain certain obnoxious substances that consume oxygen, maintaining the required minimum level of dissolved oxygen can be troublesome. One of the most economical solutions to the problem of low dissolved oxygen, especially in plants that have air compressors installed, is to enhance the rate of oxygen mass transfer.The oxygen mass transfer rate was measured in a two phase system using two different sparger arrangements, and with addition of a frother that is known to reduce the bubble size produced by the sparger. The common sparger system was shown to be inefficient compared to a readily available but under utilized method of gas dispersion which introduces air directly below the reactor turbine. Transfer of this technology to an operating plant confirmed the beneficial effect of the improved sparger system. The addition of the frother did decrease the bubble size, but it also reduced the oxygen mass transfer rate."

Jan 1, 1993

By Mark W. Masson, David B. Stevenson, David W. Broughton, Douglas R. Cruji, Steven E. Parry

"Abstract-The Amalgamated Kirkland gold deposit is located at Kirkland Lake, Ontario, within the Archean Abitibi Greenstone belt of the Canadian Shield. It lies on a fault or "break", termed the Cyprus Break, which is a splay off a regional structure termed the Cyprus-Battle Mountain Break. The Cyprus Break merges with the Cyprus - Battle Mountain Break above the -250 m level, as it was not encountered in shallow drilling or surface exploration. These structures lie 1.5 km south of the 727 000 kg (23 million ounce) Kirkland Lake Main Break and 0.5 km north of the 872 000 kg (30 million ounce) Larder Lake Break.The deposit is hosted by alkalic Timiskaming Group volcanic and sedimentary rocks which are overthrust by older Larder Lake Group tholeiitic and komatiitic flows along the Larder Lake Break. Timiskaming syenitic intrusives, similar to the host rocks for the Kirkland Lake Main Break gold deposit, intrude both suites.The Amalgamated Kirkland deposit consists of lode-style gold mineralization which is mainly hosted by altered and pyritized Timiskaming trachytic volcanics which wedge out or thin at depth, between two sedimentary units. The intersection of the Cyprus - Battle Mountain and Cyprus Breaks, in conjunction with the westward plunge of the volcanic wedge, appears to control the westerly plunge of the Amalgamated Kirkland deposit at approximately 50º.Mineralization is characterized by blue-gray brecciated and "wormy" quartz-ankerite veins which contain up to 10% fine-grained pyrite and, in decreasing order of abundance, minor galena, chalcopyrite, sphalerite, molybdenite and visible gold. The sulfides and gold commonly occur along fractures and wallrock inclusions within the veins. Native gold occurs as fine pinpoints distributed in 1-mm to 5-mm size clusters of up to ten or more grains.The auriferous veins occur within a quartz-ankerite-sericite-pyrite alteration assemblage which is enveloped by a broader zone of ankerite-sericite±hematite±quartz-pyrite alteration up to 60 m wide. This latter assemblage overprints the regional greenschist-facies chlorite-calcite assemblage.The Amalgamated Kirkland property has had a long history of exploration activity beginning with the first discovery of mineralization in 1911 on the Hunton Shaft claim located in the northeast corner of the property. Since that time various prospecting, mapping, trenching, geophysical surveys and diamond drilling programs have concentrated on either carbonate zones along the Larder Lake Break or quartz veins along the northern side of the property in association with complex trachyte flows and syenite dikes.Battle Mountain Canada Inc. located the Cyprus - Battle Mountain Break through a prospecting, trenching and geophysical program in 1989. Drilling by Battle Mountain and Cyprus Canada under the surface showing, coupled with several revisions to the structural interpretation of the Cyprus - Battle Mountain and Cyprus Breaks, resulted in delineation of the Amalgamated Kirkland deposit. Location of an auriferous structure through basic surface exploration within 1 km of a world-class orebody demonstrates both the subtle nature of Archean gold deposits and the potential for finding new mineralization in heavily prospected camps."

Jan 1, 1995

By C. Díaz, A. D. Dalvi, C. E. O'Neill

Roast-reduction smelting (RRS) of nickel concentrate, combined with flash smelting of copper concentrate, was one of the process options that Inco considered as a means of meeting its 1994 sulphur dioxide abatement target at its Copper Cliff operations. RRS involves deep roasting the nickel concentrate in fluid bed roasters. The roaster off-gas is treated in a sulphuric acid plant, and the low sulphur calcine is reduction smelted with coke in an electric furnace to yield a sulphur- deficient matte. The latter material is converted to Bessemer matte in Peirce-Smith converters, with minimal evolution of sulphur dioxide, and the converter slag is reverted to the electric furnace. Excellent nickel and cobalt recoveries (Ire obtained. This paper discusses the development of RRS, including extensive commercial scale testing at Inco's Thompson Smelter, and its key operating parameters.

Jan 1, 1994

By Sarah Belair, Gauthier Deblonde, Valerie Weigel, Alexandre Chagnes, Gerard Cote

"Niobium and tantalum are strategic metals for electronic and alloys industries. They are produced by pyrometallurgy and hydrometallurgy but most of the niobium and tantalum production processes are not environmentally friendly. For instance, in the hydrometallurgical route, niobium and tantalum separation can only be achieved by liquid-liquid extraction in the presence of hydrofluoric acid by taking advantage of the difference in niobium(V) and tantalum(V) speciation in fluoride-based media. Therefore, the environmental footprint of hydrometallurgical processes for the production of niobium and tantalum could be clearly lowered by replacing HF or NH4F by greener media such as alkaline solutions in which high solubility of niobium(V) and tantalum(V) can be achieved.The development of such new efficient and environmentally friendly hydrometallurgical processes requires a fine description of the physicochemistry of niobium(V) and tantalum(V) in alkaline solutions. Unfortunately, literature data show a huge discrepancy on niobium(V) and tantalum(V) speciation in such media. This paper gives a brief overview of the niobium(V)-tantalum(V) production processes and paves the way to the development of alternative processes in alkaline media by presenting and discussing recent advances in the physicochemistry of niobium(V) and tantalum(V) in these media.INTRODUCTIONNiobium and tantalum are strategic metals since they are used for the production of alloys and super alloys, capacitors and magnets in strategic industries such as electronic, aeronautics and automobile. The main sources of niobium and tantalum are given in Table 1."

Jan 1, 2016

By Don Lemmen

Impacts, Adaptation and Vulnerability ? regional climate changes (temperature and extreme events) have already affected many physical and biological systems ? natural systems are vulnerable to climate change, some will be irreversibly damaged ? many human systems are sensitive to climate change ? Projected changes in climate extremes could have major consequences

Nov 1, 2002

By E. L. Day

"In the early 1930s during the course of test work with a simple gold ore, it was evident that the time required to dissolve the gold by cyanidation was very much longer than should have been needed theoretically for the maximum size gold particles in the ore, A similar conclusion appeared to be valid for other gold ores. In a cyanidation system there are many factors which can influence the dissolution rate of gold, and a decision was made to investigate the more obvious variables, because a literature survey at the time showed that with the exception of the work of Yamazarki on the dissolution of silver in cyanide solution, virtually no attention had been given to this subject, Our work was not reported because the intention was to do this on completion of the Study, but owing to the demands on the Section's personnel for other work the investigation was never completed. Although other investigators have since studied the problem, the methods which we adopted and some of the conclusions may be of interest to metallurgists concerned with gold ore treatment.Form of GoldExperiments with gold ores were not possible because of the number of uncontrollable variables present in a gold ore-cyanidation system, therefore pure metal and reagents were used. Initially some experiments were carried out with gold leaf, but it was soon apparent that metal in this form was unsuitable because the uneven thickness of the leaf caused it to break up into pieces and. there was difficulty in determining precisely when complete dissolution had taken place, Numerous factors both expected and unexpected were found to influence considerably the results and much experimental work was necessary to establish the procedures which were finally adopted, Experiments were carried out with gold in the form of foil, wire, rings and sols. Finally, gold foil in the form of cylinders was adopted for most of the experiments although some work with gold in the sol form was included in the programme. Also some experin1ents were carried out with a gold ore to see if effects which were obtained with sodium chloride on gold sols were applicable to gold ores."

Jan 1, 1967

By Takao Oishi, Go Ohara, Toru Kitazaki, Masahiro Tanaka

"The High Pressure Acid Leach (HPAL) plant for nickel-cobalt mixed sulphide production at Coral Bay Nickel Corporation (CBNC) in the Philippines has been in operation since 2005 with a capacity of 10,000 t/year of nickel. Subsequent to the commissioning of the second plant in 2008, the production capacity increased to 22,000 t/year of nickel (Llerin et al., 2011). CBNC’s annual nickel production reached more than 24,000 tons of nickel in 2014. The concepts to achieve this capacity are the high availability and the reciprocally flexible operation of both plants. The availability depends on some factors, such as the control of impurities in the process and the equipment condition, to mention a few. In the HPAL process, it is not only the autoclave operating conditions that affect nickel extraction but also the impurities in the ore greatly influence it. The major element in the ore is iron and most of this iron is precipitated as Fe2O3, while the rest remains as Fe2+ or Fe3+ sulphate in solution. These ions in solution reduce the availability, so it is important to control the formation of iron ions by controlling the impurities in feed ore as well as the HPAL conditions. This paper presents the general HPAL process and the behaviour of impurities, focusing on iron behaviour in the HPAL process.INTRODUCTIONCoral Bay Nickel Corporation ProfileCoral Bay Nickel Corporation (CBNC) was founded on April 2002, as a joint venture of four companies; namely, Mitsui Corporation (18%), Sojitz Corporation (18%), Nickel Asia Corporation (10%) and Sumitomo Metal Mining Corporation (SMM) with a controlling stake of 54%. Aside from its capital share, Nickel Asia Corporation also supplies the ore and limestone for the High Pressure Acid Leach (HPAL) plant located in Rio Tuba, Philippines, as shown in Figure 1 (Tsuchida, 2008). The objective of the CBNC project is to produce 22,000 t/year (original design) of nickel and 1,500 t/year of cobalt, as sulphide, by the treatment of nickel laterite ore which is a low grade nickel oxide ore in the Philippines (Mines and Geosciences Bureau, 2014). The sulphide product has been exported as a raw material to the SMM Nickel Refinery in Japan for 30 years. The product of this plant, a mixed (Ni/Co) sulphide, is shipped to the SMM’s Nickel Refinery in Niihama, Japan. SMM Corporation provides the technology and management personnel to the plant. SMM Corporation also supplies the sulphuric acid, which is the main reagent for the HPAL process."

Jan 1, 2016

"Abstract - An estimation of resources of structurally complex gold lodes and stockworks represents a challenging task for geoscientists due to the complex geometry of the lodes and discontinuous grade. In the present case study, the resource of a gold stockwork has been estimated by uniform conditioning after the lode has been subdivided into geostatistically defined domains using the indicator probability model. The indicator probability model represents a powerful tool for structural interpretation of the mineralization and can be applied when traditional 3D volume constraining methods (wireframing) have failed to produce a unique, non-subjective model. For comparison, the resources of the same zone have been estimated without domaining. Results of the study clearly show that estimates obtained without domaining of the mineralization can yield a substantial error due to excessive smoothing of the grade.Application of uniform conditioning for modelling the grade distribution has a significant advantage over linear methods (e.g., ordinary kriging). Uniform conditioning enables estimation of local recoverable resources at different selective mining unit sizes that can be substantially smaller than the drilling density without creation of biases or over smoothed local values."

Jan 1, 2002

By Michael S. Moats, Addin Pranowo, Gerardo R. F. Alvear F., Nigel Aslin

The toxicity of arsenic is well known and documented. However, the presence of arsenic in copper electrorefining anodes and electrolyte is critically necessary to produce high quality cathode. Arsenic as well as antimony and bismuth concentrations vary depending on their relative concentration in the anode copper received from the smelter. This paper will discuss the behaviour and benefits of arsenic in copper electrorefining and the detrimental effects of antimony and bismuth on cathode quality and tankhouse performance. This will include the minimization and mitigation of problems associated with arsenic, antimony and bismuth including cathode contamination, floating slimes, scaling and anode passivation.

Jan 1, 2014

By Edgar L. Horner

"The objectives of the Wabush Mines tailings stabilization program are to control dust Ii/t-off and to rehabilitate the disposal area. The evolution of the program started with test plots in 1970, these being continued and expanded upon through 1974. In 1976, a 35-acre vegetation field trial was attempted and failed, part of the failure being attributed to lack of adequate equipment. Subsequently, equipment was purchased and during the summer of 1979-80 extensive areas were treated. The program was also expanded to include the evaluation of chemical and water spray stabilization versus vegetation in areas where shorter-term control is required. In addition, during the summers of 1979-80, spruce bog material was spread over about 100 acres and seeded.The approach to reclamation by vegetation at Wabush is one of soil building. Work to this point indicates that iron ore tailings can be converted to a soil capable of supporting plants. Plans for the Wabush tailings disposal area should make dust lift-off from inactive tailings areas negligible within the next few years."

Jan 1, 1981

By Larry T. Yano, Gerald T. Handford

"Tailings Engineering has the responsibility for planning and coordinating tailings disposal and for ensuring the stability of the tailings dyke. The inclusion of both the planning and geotechnical functions in one team has resulted in greater efficiency in the design and planning process. Major challenges in tailings disposal facing Syncrude are in the areas of: (1) sludge disposal; (2) instrumentation and monitoring; and (3) liquefaction. Meeting these challenges will have a significant effect on the cost effectiveness and reliability of the mining operation.IntroductionThe size of the tailings disposal operation has led to the establishment of a large engineering team devoted solely to the disposal of tailings. This paper discusses: the tailings disposal operation, the role of tailings engineering, the organization, inter faces, and the present and future challenges with respect to tailings disposal."

Jan 1, 1990

By J. Elbrond

"This paper describes qualitatively the progressive are losses and rock dilution in a mining project from the geological modelling to and including the concentration. A simple theoretical model of the net present value of a deposit, assuming a log-normal grade frequency function, is used to find the pair of decisions on rate of production and cut-off grade, which maximizes the net present value. Various degrees of ore losses and rock dilution are then applied on this optimum, and the resulting decreasing net present values are calculated, as well as the increasing cost of metal and the increasing metal losses as a function of are losses and rock dilution.IntroductionDue to a variety of uncertainties, to inevitable lack of precision in deposit estimation and in mine planning, and due to production constraints, ore losses and rock dilution occur throughout the many phases of a mining project. The phases range from the geological definition of the orebody, over the cut-off grade optimization and decision, over the design of the mining method and the actual mining to the ore dressing, where the final loss of valuable ore into the tailings occurs. Quantification of ore losses and rock dilution are mostly difficult if not simply impossible to obtain. At the end-phase an estimate of the total dilution may be obtained with some degree of precision by observations of the amounts and analysis of concentrate and tailings. It is much more difficult to estimate the total ore losses because the uncertainty of the geological modelling in the initial phase and in the mining phase is very difficult to quantify, despite the use of geostatistics for grade estimation.Many attempts at quantification of ore losses and rock dilution have been made and some examples are shown in Table I. Although they differ widely from each other, it is obvious from these figures that ore losses and rock dilution are significant and have considerable effects on the economical results of a mining operation. Life length, net present value, cost of producing metal and the loss of metal are all affected."

Jan 1, 1994

By J. J. Barakso, S. J. Horsky, H. V. Warren

"A review of past and present biogeochemical studies is given. Early and more recent analytical procedures are described and compared. Tables 1-5 give silver concentrations in various organs of some plant species at different localities. Table 6 and conclusions provide guidelines for exploring for silver using biogeochemistry.IntroductionBiogeochemistry has been shown to be a useful tool in the search for gold deposits, especially those of the disseminated type (Warren and Barakso 1982). The purpose of this paper is to demonstrate that biogeochemistry can also be of assistance in searching for silver concentrations buried by as much as twenty feet of overburden without inflicting any damage on the environment."

Jan 1, 1984

By Avinash Kandalam, Markus Reuter, Jörg Kleeberg, Michael Stelter

The Top Submerged Lance (TSL) technology has obtained significant importance in the pyrometallurgy industry for nearly four decades. One of the advantages of TSL furnace is its high reaction rate, which is caused by splashing and turbulence of the melt. In contradiction, this phenomenon stands as a barrier for conducting experimental investigations to validate the simulation models. The highly turbulent and splashing environment in the TSL furnace is caused due to the immersion of the lance into the slag layer and thus the effect of the flame structure is directly related to the splashing, turbulence, reaction kinetics and life-span of the lance. Moreover, the material properties such as viscosity, density and the surface tension will also influence the flame structure. As a first step to understand the flame structure, attempts are made to generate a stable flame of the lance in an open environment. INTRODUCTION Top Submerged Lance (TSL) technology was invented during the 1970s at Commonwealth Scientific and Industrial Research Organisation (CSIRO), Australia by Floyd and Denholm. This technology was later commercialised and currently, there are about 100 TSL plants around the world commissioned by various licence holders such as AUSMELT (Outotec) and ISASMELT (Xstrata- Glencore Technology). Copper is the most produced non-ferrous metal followed by lead and zinc, see Hunt (2005). Today, a wide range of primary, secondary, and complex recycling materials are used as a feed material in the TSL, Alvear et al. (2010), Kaye et al. (2008). The working principle of TSL technology lies on inserting and submerging a lance from the top of a vertical cylindrical chamber into the slag layer. The lance is considered as the heart of the furnace, where the air and fuel are transported through two concentric tubes and are mixed in a combustion chamber, which is approximately 7 cm from the tip of the lance (considering the pilot-scale TSL furnace at the Institute for Nonferrous Metallurgy and Purest Materials - INEMET). The TSL furnace is very flexible with the type of fuel, feed material and the air input. The fuel can be natural gas/heating oil/fine coal particles and the air could be enriched with oxygen (Figure 1). The general mechanism of the TSL furnace lies on feeding the material from the top of the furnace and the material is pulled into the molten bath due to the high turbulent atmosphere, which results in high reaction rates. The thermocouples installed in the furnace (i.e. in the ceramic linings) allow the operator to know the temperature of the melt. For example, in the case of copper production the tapped material (i.e. matte/metal) can be transported to a settler for further processing or directly used.

Jan 1, 2019

"Cambior currently has nearly 80 exploration properties, acting as operator on about 60 of these. The company's exploration budget has increased to over $11,100,000 for 1990. On-going efforts recently yielded a new gold discovery on the Douay- Vezza property, a joint venture project with Inco and Vior. Cambior continues to seek out new opportunities, recently acquiring an option agreement on the Sleeping Giant project in Quebec and four new exploration agreements in the United States, through its Reno office. Other nearly-concluded joint venture agreements have also given the company entries into Indonesia and Guyana.SummaryWhen it acquired SOQUEM's assets on August I, 1986, Cambior also acquired interests in 45 exploration projects. The subsequent mergers with Aiguebelle Resources and Sullivan Mines in 1987 brought the total number of exploration projects to 83, most of which are concentrated in northwestern Quebec. Cambior's strategy emphasizes gold exploration, and exploration activities were, therefore, initially limited to the Val d'Or and Rouyn-Noranda mining camps, where Cambior has a large portfolio of properties. Approximately $25.8 million has been spent on surface exploration in this area since the formation of the company, resulting in the discovery of the Mouska deposit and four sub-economic zones on the Porcupine, Forbex, Bloc Sud and Flavrian project s. In 1988, Cambior became involved in projects in the United States to which the company expects to allocate about 38070 of its 1989 exploration budget."

Jan 1, 1990

By Norman M. P. Low

"IntroductionIndustrial applications of mica utilize two commercially important varieties of mica: muscovite and phlogopite. Muscovite mica is a potassium mica with a general chemical formula, H2KA1(Si04)3 h, and is sometimes referred to as a potas hsilicate. Phlogopite is a magnesium mica having a general chemical formula, H2KMgSi(Si04)3, and is distinguished from the muscovite mica by its decomposition in sulphuric acid.Canada is one of the major natural mica producers in the world. A large tonnage of the mica powders is at present mined and processed in the Eastern Townships of Quebec. This Canadian mica is of the phlogopite type. A closely related mineral of the mica family which is widely used in the construction industry is vermiculite. It is a dehydrated magnesium-aluminum-iron silicate characterized by a foliated structure. Expanded vermiculite, which is often referred to as exfoliated mica, is used as many types of thermal and acoustic insulation, as loose fill in buildings, as an aggregate in concrete, as an ingredient in plaster and insulating concrete , and in fire-proofing compositions. Natural phlogopite and muscovite mica powders are used extensively as reinforcing agents in organic polymers. They also have a wide range of applications in commerical products. For example, dry-ground mica powders are used in large tonnage as a surface finish in roofing materials and as a bonding agent in wallboard joint cement. Common products such as paint, rubber, plastics and welding rods contain mica. Recent studies have also shown that mica powders can be added to portland cement in the preparation of concrete products, as they could improve the tensile strength of the concrete products. The potential and possible"

Jan 1, 1982

By Kari Niiranen, Andreas Boehm

LKAB (Luossavaara-Kiirunavaara AB) is operating underground iron ore mine, with three beneficiation and pelletizing plants in Kiruna, Northern Sweden. The wet low intensity magnetic separation (WLIMS) is regarded as the crucial part of silicate mineral separation from the ore. The Kiirunavaara iron ore deposit shows a rather low content of silica (ca. 2.3 to 3.3 % SiO2) but the silica grade is expected to increase in the deeper parts of the deposit. This can be problematic in the case of DR pellet quality with an average silica grade under 0.75 % SiO2. A laboratory scale methodology was developed for the systematic characterization of the ore for mineral processing with the focus on silicates at the Institute of Mineral Processing, University of Leoben. This methodology is combining mineralogical, geochemical and process mineralogical characteristics. Automated mineralogy (QEMSCAN) was used to study the modal mineralogy, the distribution of silicate minerals in different particle size classes after comminution, the deportment of silicon (Si) between various silicates and degree of liberation and intergrowth of magnetite and silicates. Based on the mineralogical investigations, actinolite, phlogopite and even quartz and albite are the predominating SiO2 bearing minerals in the ore. The important result of the investigations was the discovery of two separate subtypes within the high silica ore type B2 based on their mineralogy and mineral processing characteristics. The crucial part of the investigations of intergrowths and liberation of magnetite results was the magnetic separation tests carried out with the Davis magnetic tube. The binary intergrowths of magnetite and the silicate minerals (mostly actinolite) are the most common type of mineral association discovered. The significant characteristics in the intergrowths of magnetite and actinolite are the fine-grained magnetite inclusions in actinolite which may end up increasing the SiO2 grade in the magnetite concentrate despite magnetic separation.

Jan 1, 2016

By Peter Babik

"Cable TV networks are extensively used throughout Canada for TV signal distribution. Mobile/portable radio communications are also used extensively throughout all sectors of industry. There are numerous manufacturer supplying these industries with a wide variety of equipment and accessories.IAL's underground radio communications system combines the techniques of cable TV and mobile radio to produce a flexible communications system with most of the advantages of both systems. Standard off-the-shelf mobile, portable, base-station and repeater equipment can be used. The equipment may need modification to be customized to particular end user requirements, but does not require a complete new unit redesign. Likewise, the cable TV distribution equipment is off the-shelf, with some items requiring modification for underground system application.Radio communications can be provided wherever the cable system is extended. Where traffic or type of activity warrants it, multiple radio channels can be provided on the same cable. Certain radio channels could also be used with data channels for control or supervision of remote equipment or environmental conditions. In addition, the same cable can be used to distribute or monitor signals from remote TV cameras in selected or dangerous areas. The system can be interfaced to a telephone system, if required, to provide extended communications to above-ground workshops, offices, medical stations or even hospitals and other emergency services.IntroductionReliable communications among personnel throughout an underground mine area have long been the dream and goal of various mine operations personnel. The system to be described was designed to meet this objective."

Jan 1, 1983

By C. Díaz, A. D. Dalvi, C. E. O'Neill

"Roast-reduction smelting (RRS) of nickel concentrate, combined with flash smelting of copper concentrate, was one of the process options that Inco considered as a means of meeting its 1994 sulphur dioxide abatement target at its Copper Cliff operations. RRS involves deep roasting the nickel concentrate in fluid bed roasters. The roaster off-gas is treated in a sulphuric acid plant, and the low sulphur calcine is reduction smelted with coke in an electric furnace to yield a sulphur-deficient matte. The latter material is converted to Bessemer matte in Peirce-Smith converters, with minimal evolution of sulphur dioxide, and the converter slag is reverted to the electric furnace. Excellent nickel and cobalt recoveries (Ire obtained. This paper discusses the development of RRS, including extensive commercial scale testing at Inco's Thompson Smelter, and its key operating parameters. IntroductionReduction of sulphur dioxide emissions has been a long-standing endeavour at Inco. At the company's Ontario Division, as shown in Figure 1, sulphur dioxide emissions were reduced from about 2 million to 685 000 tonnes per year over the period 1970-1985. Most of this impressive improvement was the result of a sustained research effort which led to increased rejection of pyrrhotite from the ore during milling while maintaining an acceptable nickel recovery. Between 1970 and 1985, the combined grade of the separate nickel and copper concentrates feeding the Copper Cliff Smelter increased from about 10070 to about 'lIJ0J0 Cu +Ni and the combined S/(CU +Ni) ratio decreased from about 2.8 to 1.65."

Jan 1, 1994