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By D. C. Kaliampakos, A. G. Benardos

The existence of quarries near or even within the boundaries of urban centres is the cause of many environmental problems, despite their significant contribution to the cities’ development. Hence, the question arises as to how quarrying activities can be compromised within the spirit of sustainable development in big cities. In the case of Athens, two dominant, though opposite opinions have been formed. The first argues that all quarries must be forced to suspend their activities as soon as possible; the second presses for the continuation of quarrying. Consequently, the question is transposed on the dilemma between improved environmental conditions and economic development. This paper demonstrates that if a complete redesign is employed to specific, nonvisible quarrying sites, the continuation of quarrying activities is acceptable. It is a good compromise between the economical demand and environmental protection.

Jan 1, 2000

By H. M. Lewis

The current status of the international zinc market is summarized, and a supply /demand outlook is presented for the next five years. A number of technical problems facing the industry are outlined. Introduction ZINC has sometimes been called the unknown metal. Considering that on a world basis it ranks third among non-ferrous metals in production and consumption, zinc retains a certain modesty. It has no distinctive colour like copper, lacks the low density of aluminum or magnesium and is not always easy to identify as a product. The 'spangle' of galvanized steel is probably zinc's most distinguishing feature. The purpose of this article is to develop an over-all review of zinc. Starting with the current position of the metal, the major factors that will shape its future will be described so that an assessment of the outlook for zinc can be made.

Jan 1, 1978

By W. E. Kuhn

Introduction The work, of which some of the results are described in this paper, was started with the object of investigating the properties of certain binary alloys of titanium made from powders. Our main interest was in the possible use of such alloys in gas turbines. We were attracted to titanium, as have been others, by its high melting point (I,724° ± 11°C.), its low density (4.54), and the likelihood that, if a relatively wide use could be found for the metal, it might become available in commercial quantities at a fairly reasonable price. The readiness with which the metal reacts with hydrogen, oxygen, and nitrogen was recognized from the very beginning. At the same time there seemed a good chance that alloys could be produced which, because of the formation of protective films, would resist the attack of these and other corrosive agents. No specifications were drafted to cover the 'quality' of the titanium hydride powder which was used in our work and which was, to judge by the results of a few preliminary experiments, the most useful source of titanium then (1944) available in sufficient amount for our purpose. During the course of our work, the need for such specifications became very clear (see Sections 9 to 12 of this pa per). Even today, lack of knowledge regarding the effects on titanium of impurities, some of which may later be looked upon as essential elements in commercial alloys of titanium, and difficulties in manufacture, make the preparation of specifications for commercial titanium and titanium compounds a doubtful procedure. The papers presented at the 1948 Symposium on Titanium, sponsored by the U.S. Office of Naval Research lend colour to this view. At the time our work was commenced, one had to depend upon the manufacturer to supply what he considered to be his 'best' material. It may be some time before we can ask for more than this, the question as to what is his 'best' being left to the manufacturer to decide. However, in this connection the results of our study may be of some value and on that account we are constrained to publish them.

Jan 1, 1950

By N. H. Grace

"IntroductionDURING the past half century, the economy of Western Canada was largely centred on agriculture. However, the impact of World War II has led to an acceleration in the development of a variety of natural resources so that, today, Western Canada is experiencing great industrial development. Consequently, the availability •of low-cost energy assumes prime importance. In the final analysis, industrial growth and expansion are intimately linked to the energy resources.Coal ReservesHas Western Canada adequate coal reserves to meet the present accelerating demand for power in the days that lie ahead? This question must be answered before detailed consideration can be given to the probable patterns •by which various energy sources in Western Canada may be expected to meet the expanding demand. Figure 1 indicates the extent and distribution of the Canadian coal reserves, the data having been prepared by Dr. B. R. MacKay for the Royal Commission on Coal in 1946 (1). The amount of readily recoverable coal is listed as one-half the quantities shown on the chart. It is interesting-to note that upwards of 90 per cent •of the Canadian coal reserves .are located in the three most westerly Canadian provinces. It has been estimated that the coal reserves, at the present rate of mining, would be adequate for about 3,000 years. Consequently, it may be concluded that the coal •reserves in Western Canada •are indeed adequate to meet tremendous energy demands for many centuries. When the oil and natural gas have been exhausted, the great coal reserves will still be available."

Jan 1, 1953

By Kenji Koga

In order to derive the population distribution of gold nanoparticle morphologies as a function of size, highresolution electron microscopic (HREM) observations and structural analyses were done for over 4000 particles (3-18 nm) grown by an inert gas aggregation (IGA) source using helium. To obtain structural features threedimensionally and not to skip high-contrast images, twenty photos were taken for each particle by changing tilting angle of a specimen holder in combination with the through-focus procedure. For the reliable structural determinations, HREM images and their tilting sequences were directly compared with multislice-simulation results for icosahedral, decahedral and face-centered cubic morphologies, and finally the population distribution of each morphology was obtained as a function of size. In the present sample, icosahedral particles were dominantly populated over the whole observed size range and decahedral particles with non-spherical truncated bi-pyramid shape were secondly dominant. Even though a large number of sampling has been done, few crystalline particles were observed.

Oct 1, 2003

By A. R. Byers

"This paper describes the distribution, occurrence, and paragenesis of known sulphide deposits within an area bounded by longitudes 102°00' to 106°00' west and latitudes 54 ° 301 to 57 °00 1 north. The Precambrian bed-rock which outcrops over all but the southern fringe of the area con- . sists of regional metamorphic assemblages ranging from low grade or green schist facies to high grade or amphibolite-granulite facies. The areas . of low-grade metamorphism correspond to 'islands' of volcanic rocks which are surrounded by highgrade paragneisses and migmatites. Intrusive rocks range in composition from ultrabasic to granitic and may be divided into syntectonic and posttectonic sequences. The average composition of the former is granodiorite and of the latter quartz diorite.The massive sulphide deposits fall naturally on basis of mineral content into the following divisions: ( 1) pyrrhotite and / or pyrite, (2) sphalerite and/ or chalcopyrite plus iron sulphides, (3) sphalerite and galena, ( 4) sulphide-bearing pegmatite, and (5) nickeliferous pyrrhotite and / or chalcopyrite. The deposits of iron sulphides are ubiquitous. Ratio of pyrrhotite to pyrite is fairly constant for individual deposits, but their areal distribution appears to be independent of the nature of the enclosing rock and grade of regional metamorphism. All deposits containing ore-grade quantities of base metals have been concentrated at favourable structural locations. Copper-zinc and lead-zinc deposits appear to be associated with syntectonic granodiorite with the lead-zinc concentrations confined to calc-silicate gneisses. Copper-nickel deposits show a close relationship to post-tectonic gabbros and pyroxenites. The paragenesis is more or less the same for the majority of deposits, with iron sulphides and sphalerite being introduced early and followed by chalcopyrite and galena. Some vertical and / or horizontal zoning is apparent in a few deposits. Temperatures of formation and origin of the deposits are briefly discussed."

Jan 1, 1960

By M. S. Badollet

INTRODUCTION THE DEMAND for general knowledge on asbestos fibres has increased considerably in recent years. A few publications have printed data showing some of the physical and chemical prupertie3 of asbestos, but in many cases this information is difficult to find and is seldom available when needed. During the past ten years, Johns-Manville have received many inquiries on the physical and chemical properties of asbestos fibres. Fortunately, we had some of the information in our files, and we willingly supplied the data. To help relieve this need, we have tried to present briefly in this paper some of the interesting and out-standing properties of asbestos. This information was obtained over a period of years by search of the literature and by experimental investigations. PROPERTIES OF ASBESTOS FIBRES Table I (1, 2) presents, in convenient form for easy comparison, data on the principal properties of the several varieties of commercial 'asbestos' -actinolite, amosite, anthophyllite, chrysotile, crocidolite, and tremolite. Under each variety of fibre is a brief statement describing the properties in terms of structure, mineral association, origin, etc. Some of the more important data in Table I are expanded and presented in Table II (3). SOLUBILITY OF ASBESTOS A report ( 4, 5) discussing the effects of acids and caustic on asbestos fibres was published in Germany in 1927.

Jan 1, 1951

By Carol E. Jones

Outline ? Reclamation is a primary mitigation. ? Understand baseline environment and land use. ? Determine reclamation goals. ? Selecting reclamation technology. ? Determine technical risk. Reclamation ? Primary Mitigation ? Through land and water disturbance, mining can have significant local and regional environmental impacts. ? Impacts can also result from associated land use changes. ? Reclamation is a primary tool that the mining industry uses to manage its environmental impacts.

May 1, 2008

By Dr. G. R. Hoey

"Abrasive wear and corrosive wear of carbon-steel grinding balls occurred simultaneously during the wet-grinding of hematite iron ore, and Ni-Cu sulphide ore, in laboratory ball mills. Two corrosion control methods, the use of corrosion inhibitors and pH control, were investigated and found to be effective means of reducing or preventing corrosive wear. Up to 50 % reduction of total ball wear resulted from the use of these methods.Corrosive wear is caused principally by the reaction of oxygen in air with the carbon-steel grinding balls, probably by the following reaction: 2Fe + O2 + 2H20 - 2Fe2 + 40H-.IntroductionA survey of corrosion problems in Canadian sulphide ore mines was completed and the findings were published in 197l(l). The corrosion survey was used to develop the present research program with the objective to find more economical and effective ways and means to reduce the corrosion that occurs in the mining and metallurgical industry. The purpose of this presentation is to review the projects being done by staff members of the Corrosion Section, Extraction Metallurgy Division, on corrosive wear and its control in wet-grind ball mills.Both abrasion and corrosion contribute to metal consumption during wet grinding of ores. The total wear of grinding media in this study is assumed to be equal to the sum of corrosive wear and abrasive wear. A great deal of research and development has been reported in the literature on ways to improve the abrasion resistance of grinding media but only a small number of studies has been reported on the corrosion resistance of conventional grinding media."

Jan 1, 1974

By Derek H. C. Wilton, David T. W. Evans

"Abstract - The Midas Pond gold prospect, central Newfoundland, is hosted by sheared and altered felsic and mafic pyroclastic rocks of the Tulks Hill volcanics, Victoria Lake Group, and has been trenched and tested by 19 diamond-drill holes. Gold values are sporadic, with the best diamond-drill intersection assaying 7.3 g/t over 0.9 m, and the highest grade channel sample containing 14.7 g/t over 1.15 m. Alteration and mineralization are confined to a 200 m wide brittle-ductile shear zone. This shear zone formed in response to regional D1 deformation, and the shear zone fabric parallels the regional S1 foliation. D2 deformation resulted in broad Z-shaped flexuring of the shear zone. The deformation was probably related to the ca. 396 Ma to 420 Ma Salinic Orogeny.Advanced argillic alteration and an extensive halo of Fe-carbonate and pyrite surround the gold mineralization. Alteration minerals include pyrophyllite, paragonite, quartz, plagioclase, chlorite, fluorite, Fe-carbonate, and pyrite. As such, the alteration seems to reflect combined epithermal (argillic) and mesothermal (carbonate) mineralizing environments. The argillic alteration and fluorite represent a regional hydrothermal effect on the felsic volcanic rocks; whereas, the Fe-carbonate and pyrite represent a mesothermal alteration associated with auriferous quartz veins. The Au, which is spatially associated with pyrite, occurs in three structurally-controlled vein sets. These veins are confined to the contact between a highly deformed breccia (the banded mafic tuff) and structurally overlying, altered felsic tuffaceous rocks. The vein sets include: V1 boudinage veins that parallel the shear-zone fabric (C-shear veins), and V2 and V3 extensional fracture veins which are controlled by an S2 fracture cleavage. V1 veins are the earliest and contain the lowest concentrations of Au. V2 and V3 veins are concentrated within the hinges of the D2 flexures.Pb isotope data for galena separates indicate that the Pb in the vein systems was probably of local derivation. Sulfur, C, and O isotope data for mineral separates are similar to data for typical mesothermal lode gold deposits. Fluid inclusion data suggest the presence of at least three hydrothermal fluid types in the region, viz., (1) an early saline fluid which produced the argillic alteration, (2) a CO2-bearing fluid directly related to the auriferous mineralization, and (3) H2O-NaCl fluids which flowed through the Midas Pond shear zone at a lateral distance from the zone of mineralization. The mineralizing fluids are interpreted to have been CO3 -2-rich types which originated through metamorphic dehydration and decarbonation of mixed island-arc and continental crustal rocks. Gold precipitation resulted from the reaction of these fluids with the Fe-rich breccia unit. Pre-existing and simultaneously crystallizing pyrite served as loci for Au precipitation."

Jan 1, 2000

By Charles T. Harper

The uranium deposits discovered by Amok (Canada) Ltd. in the Cluff Lake area of north western Saskatchewan occur at or near the southern edge of the uplifted basement core of the Carswell circular structure. Two types of mineralization, distinguishable, by their geological and structural setting and mineral paragenesis, have been recognized. The N-Claude type is characterized by a relatively simple mineral assemblage, consisting of uraninite or pitchblende with coffinite, and is accompanied by variable amounts of graphite and organic matter, and Fe, Cu, Pb and Mo sulphides. Both N and Claude orebodies occur within quartzofeldspathic gneisses of the basement core. On the other hand, the D-type ore has a complex mineral assemblage consisting of: uraninite, pitchblende, thucholite and coffinite, along with native gold and selenium; gold tellurides, and selenides of Pb, Bi, Ni and Co; sulphides of Fe, Cu and Pb; and organic matter. The D orebody occurs within carbonaceous shales at the base of the Athabasca Formation as well as in fault zones in regolithic quartzo feldspathic gneisses above the inverted unconformity. An age of 1050 m.y., which is consistent with a period (circa 1200-1000 m.y.) of widespread hydrothermal activity and uranium mineralization or reworking within and adjacent to the Athabasca Basin, has been obtained from uranium mineralization from the D orebody. Later reworking (circa470 m.y.) of the mineralization occurred at the intersection of older mineralized shear zones with radial faults produced during meteorite impact.

Jan 1, 1978

By D. S. Robertson

More than 700,000 feet of diamond drilling was completed in the Blind River area between 1953 and 1958. Much of this drilling was at depths which are still not usual in North America. However, as the tendency is to deeper holes, factual data from the Blind River operation may well provide information of value in future programs. Rates of drilling decreased with in-creasing depth, but uncommonly good rates (an average of over 50 feet per day over more than 4,000 feet of hole) were achieved with proper engineering and care. Costs varied as contractors and geologists became familiar with the area Hole deviation in the Blind River area was locally severe and control of the hole trace became a major problem. Careful surveying was necessary and found to be highly re-liable. It was found that control of the hole trace above 1,500 feet was much more difficult than at depths below 1,500 feet. This is explained by the mechanics of the drilling operation. Various methods of controlling hole deviation were attempted and,

Jan 1, 1962

By J. C. Bothan

A program to provide technical in-formation on the use of fuels in pyro-metallurgical processes, from the Canadian fuel viewpoint, was initiated about five years ago by a Canadian Institute of Mining and Metallurgy liaison grou1> composed of members from the Coal Research Committee of the Coal Division and the Iron and Steel Committee of the Metallurgy Division. This paper is another of a series prepared for this program. Previous papers included a review of pyrometallurgical processes of Canadian interest, a survey of ferrous processes relevant to the development of an integrated steel industry in western Canada and a survey of the fuel requirements of the non-ferrous metals industry in Canada. It is widely recognized among per-sons familiar with the Canadian coal industry that, because of the large resources of coking coal in western Canada, the

Jan 1, 1963

By M. A. Rabah

This study aims to recover europium, yttrium metals, some valuable salts or oxides from the white powder (apatite) coating the inner surface of spent florescent lamps (SFLs). Pressure leaching using sulphuric/nitric acid successfully dissolved the metals of interest. Europium or yttrium metals were obtained by hydrogen reduction of their oxides. Addition of potassium thiocyanate converted the dissolved sulphates to thiocyanates. Selective separation of Eu and Y was then carried out by solvent extraction from the thiocyanate solution. The used solvent was trimethyl-benzylammonium chloride. N-trihutylphosphate in 1 M nitric acid was used to strip the metal loaded in the organic phase. Results showed that the quality of the cleaned glass tubes of the SFL met the standard requirement for the lamp manufacture. The white powder (WP) is composed of calcium sulphate 35.2%, phosphate 61.5% and oxides of europium and yttrium 1.65%wt. respectively. Autoclave digestion of the WP for 4 h at 120°C and 500 kPa in sulphuric acid/nitric acid mixture dissolved 96.4% of yttrium and 92.8% of europium. The conversion rate of sulphate to thiocyanate was favoured at low temperature. Stripping of Eu and Y from the loaded organic phase behaved in an opposite way. A metal separation factor of 9.4 was obtained. ate recovered europium and yttrium salts were selectively separated using ethyl alcohol or dilute nitric acid. Yttrium was very soluble while europium was not. Europium and yttrium metals were obtained by hydrogen gas reduction at 850°C and 1575°C respectively.

Jan 1, 2004

By J. Bélanger, B. Semlali, M. Grenon

RÉSUMÉ La conception des fosses ainsi que l'évaluation des ressources géologiques et des réserves minières sont désormais réalisées entièrement à l'aide d'outils informatiques spécialisés. Cependant, plusieurs analyses, pourtant essentielles à l'évaluation de la viabilité du projet, sont réalisées en parallèle sans véritable optimisation ni synergie avec l'ensemble des données disponibles. Cet article présente deux approches permettant d'intégrer certains types d'analyses aux modèles de blocs miniers. Ces approches permettent de quantifier la broyabilité du massif rocheux ainsi que d'étudier la stabilité des pentes minières à même les outils d'optimisation et de planification minières. Cette méthode permet dès l'étude de faisabilité d'un projet minier de maximiser les données disponibles, menant ainsi à une approche plus intégrée en conception minière. De plus, ces approches sont flexibles et permettent d'évaluer rapidement plusieurs scénarios, tout en laissant la possibilité de bonifier le modèle et de revoir la conception tout au long du projet minier.

Jan 1, 2010

By G. E. Norman, A. L. Mckague

"The new smelting process commenced operation in 1978. The pelletizing and sinter plants were replaced with slurry-fed roasters and the blast furnaces with electric furnaces. The existing converter aisle and matte handling facilities remained unchanged.Process DescriptionNickel-copper concentrate is partially roasted in two slurry-fed fluid bed roasters. After gas cleaning, the sulphur dioxide gas is transferred to the acid plant. The roaster product is conveyed to two electric furnaces for smelting to produce a waste slag and furnace matte. The slag goes to the disposal area and furnace matte containing the metal values is processed in the converters for further removal of iron and sulphur.The final matte containing about 75 per cent metal values is shipped to the refinery in Norway.The commercial smelter was designed for 2135 tonnes per day of concentrate, with an availability of 85% . Roasters and electric furnaces were sized at 117 per cent of design, or 1250 tonnes per day on each of two lines. Concentrate storage capacity in the plant is sufficient for two to three days' plant operation.The new smelting process will be discussed under the following headings:Concentrate Slurry HandlingFeed PreparationRoaster OperationRoaster Gas CleaningCalcine TransferElectric Furnace Operation and Process Control Converting and Matte HandlingUnder these headings, process control , equipment changes, and plant performance after three years' operation is reviewed. A brief discussion of accident prevention , and working environment is also included ."

Jan 1, 1984

By E. M. Cameron

Reconnaissance radiometric and geochemical data have been obtained for an area on the western shore of Wollaston Lake that includes the Rabbit Lake uranium deposit. The study area is extensively drift cover ed. The geochemical data were obtained by analysis of center-lake sediments and surface waters for a variety of elements and other constituents. The airborne radiometric data comprise measurements of eU, eTh and K obtained with a .50,000-cc NaI (Tl) detector at a mean terrain clearance of 120 m and 5-km flight-line spacing. Uranium in lake sediments and uranium in waters are the most effective geochemical indicators of uranium mineralization; the other elements measured are not notably anomalous. A sample site density of one per 1 8 km 2 is more than adequate for identification of the mineralized area. Because many water samples contain close to or below the current analytical detection limit of 0.05 ppb U, the use of sediments is generally favoured. for broad-scale reconnaissance in the region. Uranium in these lake sediments appears to be little influenced by variations in the organic or iron and manganese content. The most effective radiometric indicator of the mineralization is the eU/eTh ratio. This parameter is less influenced by environmental variation on the ground beneath the flight line than eU alone . The eTh/K ratio is anomalous under the Athabasca Formation unconformity where, in places, the uranium mineralization is localized.

Jan 1, 1977

By J. A. Russell

AS THE LOCAL electric generating plants increased in size and capacity and costs of producing electricity came down, it became apparent that it was no longer good economy to operate individual boiler plants at the Company's various collieries to power steam hoists and compressors. Great economies could be made by burning the Coal at central power plants and using electric power at the collieries. During the period after the end of the war, a steady and continuing programme of replacing first the smaller steam-driven units, and later the steam-driven compressors, was undertaken, and finally the larger hoists, those at No. 12 Colliery in New Waterford and No. 20 Colliery in Glace Bay, were the last units operated by steam.

Jan 1, 1958

By A. H. Mumin, A. Prikhodko

"This paper provides an understanding of interpreting and evaluating airborne time domain electromagnetic (TEM) surveys as applied to massive sulfide exploration. Variations in the conductive morphologies of massive sulfide ore systems are discussed, followed by forward modelling exercises examining the derived TEM response to these morphologies and discussion of the subtleties of data interpretation. Deposit morphology in the orientation at formation and the variations occurring due to later deformation are considered. Images of corresponding resistivity–depth models are provided. The combined modelling results provide a low-cost method for initial interpretation and screening of TEM anomalies. RÉSUMÉ Cet article nous permet de mieux comprendre l’interprétation et l’évaluation des levés élec-tromagnétiques aéroportés en domaine temporel (TDEM, de l’anglais time-domain electromagnetic) appliqués à l’exploration du sulfure massif. Y sont débattues les variations au niveau des morphologies conductrices des systèmes de minéralisation du sulfure massif, suivies d’exercices de modélisation prospective qui examinent la réponse dérivée des TDEM à ces morphologies et d’une discussion sur les subtilités de l’interprétation des données. L’étude envisage la morphologie de l’orientation originelle non déformée des gisements ainsi que les variations résultant d’une déformation ultérieure. Des images des modèles correspondants de résistivité-profondeur sont fournies. Les résultats combinés relatifs à la modélisation proposent une méthode peu onéreuse d’interprétation et de contrôle initiaux des anomalies dans les TDEM.INTRODUCTION Electromagnetic geophysical surveys are an indispensable foundation of many mineral exploration programs and can account for as much as half of the predrilling exploration costs. Quantitative mass interpretation of the survey results remains difficult due to the infinite variation of deposit morphologies, their complex physical properties, and the presence of barren conductive materials that can mimic or mask the response of targeted ore. Many modern geophysical investigations that focus on time domain electromagnetic (TEM) data interpretations are devoted to problems with inversion and modelling and their algorithms. Although a few of these investigations have resulted in commercial software products, these require highly qualified and experienced users and usually include geometric assumptions. Furthermore, without the input of known physical properties and geometric constraints, the inversion results are highly ambiguous. A number of case studies document the geophysical responses to known targets in well-defined and diverse geo-electrical environments, providing a high degree of correlation between field obser-vation and the results of the modelling used in this style of investigation (Hone, 1980; Schneider & Emerson, 1980; Tyne, Idnurm, & Malone, 1981; Bishop & Lewis, 1992; Hopgood & Hungerford, 1994; Meju, 2002; Yang & Oldenburg, 2016). The uniqueness of the target/environment parameters and their specific features limits the use logy is poorly understood. The responses are therefore that are devoid of complicating environmental factors (e.g., highly conductive overburden and hostrocks or nonuniform target conductivity) as a first approach to the interpretation process of such case studies as the main reference for interpreting TEM survey responses in areas where the underlying geomodelled from generalized and typical geological models"

Jan 1, 2018

By G. E. Agar, W. B. Kipkie, R. A. Tenbergen

"This paper describes the successful pilot plant testing of a flowsheet, developed at Inca Ltd.&apos;s J. Roy Gordon Research Laboratory (JRGRL), for improved separation of the constituent minerals in a bulk copper-nickel concentrate.The flowsheet utilized the fact that xanthate concentration on the mineral surfaces is the most important variable affecting the high lime separation and that reduction of the xanthate concentration could be affected by an oxidative conditioning stage.When the adsorbed xanthate was reduced to a suitably low level, chalcopyrite and pyrrhotite could be floated to leave a high-grade nickel concentrate as the residue. Sodium cyanide was added to the froth product 10 depress pyrrhotite and any remaining pentlandite. The temporary depression of chalcopyrite by the sodium cyanide was overcome by introducing a conditioning step following cyanide addition . The advantages of the flowsheet; improved copper-nickel separation, operation without heating of the pulp, production of both high-grade nickel concentrate (29.5% Ni, .26% Cu) and copper concentrate (<0.5% Ni, 30% Cu) were all realized.IntroductionLaboratory test work undertaken at Inco and described previously(1) has demonstrated the importance of low xanthate concentrations on the mineral surfaces in the copper-nickel separation at the Copper Cliff mill.It was determined that oxidation of the separator feed (a cleaned bulk concentrate, grading about 11% Cu and 11% Ni) to lower the xanthate concentration on the mineral surfaces prior to separation significantly improved the quality of the separation (CI 4)*, particularly when no cyanide is used, but also when cyanide is added. As well, it was found that the oxidation permitted a pentlandite-pyrrhotite separation - the oxidation step brought about a decrease in the flotation-rate of pentlandite leaving pyrrhotite and chalcopyrite largely unaffected. Consequently, it was possible to produce a highgrade pentlandite product (30% Ni, 0.3% Cu) at ~83% Ni recovery , as well as a high-grade copper concentrate (0.5% Ni, 30% Cu at -96% Cu recovery)."

Jan 1, 1985