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By Brian Hart, Stamen Dimov

"The Time of Flight Secondary Ion Mass Spectrometer (ToF-SIMS) is unique in that it measures the outermost atomic layers of any material. The technique is particularly suited for determining surface chemical composition of mineral particles. It is most commonly used as a diagnostic tool to measure mineral surface chemical variability in plant and bench top flotation separation processes. Recently, research towards understanding the full capability of the instrument has resulted in the development of new diagnostic applications related to various Au extraction technologies and the development of the ToF-SIMS as a predictive tool for assessing the chemical reactivity of the ore.In this paper we will present a brief review of the ToF-SIMS technique with recent advances in instrumentation and methodologies including:•,?recent developments and advances towards a semi-quantitative approach to the evaluation of mineral surface modifiers (ex. Cu),•,?flotation case studies investigating activator, depressant and collector loading variability within a flotation process,•,?the recently developed chemical reactivity test which we believe has the potential to predict the behaviour of minerals in a flotation test in response to chemical transfer during grinding,•,recent applications for determination of surface Au preg-robbed in carbonaceous materials.A portion of this material has been recently presented at the COM 2009 meeting and at SIMS XVII (see Dimov et al 2009 and Hart et al, 2009).INTRODUCTIONIn flotation seperation surface chemistry is the principal determinant for selective separation of the various mineral phases (Ralston, 1994, Smart et al, 2003). Determination of this hydrophobic/hydrophilic balance by particle therefore requires correct identification and selection of the particular mineral phase(s) followed by a statistical analysis of the surface chemical characteristics of the particles with an estimation of the spread of values (Smart et al, 2003)."

Jan 1, 2010

By R. J. Fruehan

Oxygen steelmaking (OSM) is not only the dominant steelmaking process but defines the structure of the industry. There are a number of myths regarding the future of OSM, which are false. These myths include that the EAF will become the dominant process in the near future, it is less costly to produce steel in an EAF and OSM is a mature technology and no new developments are occurring. These myths are shown to be false. Selected new developments are discussed such as post combustion, recycling of waste oxides, slag splashing and sensors.

Jan 1, 2004

By R. B. Throndycraft

"1. Belt-Drop Agglomeration Preferred at Heap Leach Operations. The agglomeration method now preferred at heap leach operations utilizes belt-drops along conveyors. Belt-drop agglomeration is being designed into numerous upcoming heap leach operations. It offers substantial capital cost savings over previously favored drum agglomerators. It has such significant operating and maintenance advantages that some drum agglomerators have been retired in favor of belt-drops.The majority of heap leach operations are now built with crushing included in the flowsheet. If crushing is included, belt-drop agglomeration can be added for almost no cost. The agglomeration equipment is simply a few conveyor transfers, designed to provide the tumbling and rolling action which forms the agglomerates. Controlled water sprays are needed at each of these agglomeration transfers. Cement or lime is added as a binder, to stabilize the agglomerates. This reagent is also needed to raise pH to safe operating levels.Addition of the pH control reagent before stacking the ore offers a reagent cost benefit. In the belt-drop mixing technique, the ore is intimately mixed with the lime (or cement). After stacking on the heaps, when the cyanide solution is sprayed onto the high-ph ore, very little cyanide is consumed. Without the pre-addition of lime or cement, the leach solution is sprayed onto neutral ore. The mixture of high-pH leach solution and neutral pH ore causes the solution pH to drop, releasing cyanide gas. This release is minor from a safety viewpoint, much less than dangerous, but the gas release is a costly waste of the cyanide reagent. Pilot-scale comparison tests were made at Pinson. Ore pre-treated with lime or cement showed 30% less cyanide consumption than untreated ore."

Jan 1, 1989

By Rees J. Llewellyn

High chromium white irons can be formulated to provide required combinations of abrasion and erosion wear resistance, toughness and capability to withstand corrosion attack. As a consequence, they are used widely in casting form throughout the mining/mineral processing industry, particularly as components for slurry pumps and also as mill and crusher liners, laminated wear plates in chutes and hoppers and in valves, nozzles and cyclones. Traditional cast chromium molybdenum and high chromium white irons for wear applications are covered in ASTM A532 Classes 11 and 111 and are also available as comparable proprietary alloys. They rely on heat-treated, hypoeutectic microstructures containing a high volume fraction of very hard eutectic/secondary metal carbides and martensite to provide extremely high wear resistance. The ability to increase the carbide volume fraction and hence achieve higher wear resistance, has been limited because of severe casting difficulties encountered when carbon and chromium contents are raised and hypereutectic alloys with structures also containing coarse acicular primary metal carbides are produced. The limitation has been overcome and cast hypereutectic chromium white iron pump components have established themselves in a wide variety of mineral processing service applications. Comparisons will be made between the microstructures and wear test performance data for the various alloy types and details will be provided of the service performance improvements that have been achieved through the use of hypereutectic chromium white irons.

May 1, 2004

By D. M. MacLean

THE property of Howey Gold Mines, Limited, is situated at Red Lake, Ontario, one hundred and seventy-five miles east of Winnipeg and eighty miles north of the Canadian National railway. The mine has been a continuous producer since April, 1930, and, at present writing, a total of 3,042,690 tons has been hoisted, giving a production of $6,422,858.55, for a grade of $2.32 per ton. From 1,064,477 tons mined during the past two years, however, the yield has been only $1,389,607.03, or $1.41 per ton (gold at $20.67). Present output is at the rate of about 1,470 tons. per day. THE ORE-BODY AND WALL-ROCK: The Howey ore-body is part of a quartz porphyry dyke, which has. intruded an area of greenstone. The dyke strikes north 65° east, and its dip varies from 85° to the south at the surface to practically vertical below the. 1,000-foot horizon. Both along the strike and on the dip, the width of the dyke varies from 25 to 200 feet, the widest portion occurring below the 1,000-foot level. To the east of the ore-body, the dyke increases in width and finally splits into tongues of porphyry enclosed in greenstone, diorite, and congloJ11erate. To the west, it passes into the adjoining property, its width at the boundary being 100 feet. The rock in the ore-body is hard to drill, but, because of numerous horizontal slip-planes, it breaks well when blasted. This characteristic makes it possible to break large breasts or benches with a relatively small number of holes. The ore broken in this manner is consequently quite coarse, a large part of it requiring secondary breaking.

Jan 1, 1938

By P. M. Daignault

"Fording Coal Limited is one of Canada's largest producers of metallurgical coal for the export market. Medium- to highvolatile coals are mined at its Fording River operations in southeastern British Columbia. This paper discusses some of the mine design and production related problems encountered, and how they have been resolved. Other aspects of the operation such as geography, geology and standard mining methods employed are also covered.IntroductionFording Coal Limited was formed in 1968 to mine and market metallurgical coal resources held by the company in the East Kootenay region of southeastern British Columbia<1>. The company, at its Fording River operations, holds approximately 19,635 hectares of coal lands, having an estimated resource of 3.5 billion tonnes of metallurgical coal. Total reserves are approximately 520 million tonnes.Fording Coal is owned 600Jo by Canadian Pacific Enterprises Limited and 400Jo by Cominco Limited. Cominco itself is owned approximately 540Jo by Canadian Pacific Enterprises. The company, originally staffed and managed by Cominco, has been independent since January 1978, with its own board of directors, management, staff and employees. The head office is in Calgary, Alberta. The Fording River operations are located in British Columbia, approximately 70 km north of the Crowsnest Pass, near the Alberta/ British Columbia boundary, only 150 km by air and 320 km by road from Calgary.A contract was signed in 1969 with the Japanese steel mills to provide 45. 7 million tonnes of metallurgical coal over fifteen years, commencing in 1972, at an annual rate of 3 .05 million tonnes per year. The mine is presently expanding annual production capacity from the original 3.0 million long tons (3.05 million tonnes) to in excess of 5.0 million tonnes.Concurrent with this production expansion, a vigorous marketing effort has diversified Fording's customers to include additional countries in the Pacific Rim area. Three cleaned coal products are now marketed compared to the single ""standard blend"" product originally shipped to satisfy the Japanese contract. The product specifications are listed in Table I."

Jan 1, 1985

By S. G. Luckey, N. R. Harrison, F. Nadeau, U. Brüx

"The adoption of tailored-rolled or tailor-welded blanks (i.e. TRB/TWB) in the automotive industry has been known to offer great potential for the optimization of weight, function, cost and complexity. Vehicle light weighting can further be achieved by using high strength aluminum alloys like the 7xxx-series. 7xxx-series alloys are capable of delivering specific strengths equal to or greater than high strength steels. However, room temperature formability of this aluminum class is limited, so one approach to forming 7xxx-series alloys is by hot stamping. Hot stamping utilizes an elevated temperature blank and the high pressure stamping contact of the forming die to simultaneously quench and form the sheet. This paper explores the initial feasibility of tailored thickness material for body-in-white applications when processed under hot stamping conditions.INTRODUCTION Steel tailor-rolled blanks (TRB) or tailor-welded blanks (TWB) have been used within the automotive industry as a method of reducing weight, expanding material utilization, and decreasing overall part/assembly cost (Ganeasan et al., 2015; Merklein et al., 2014; Hirt et al., 2005; Kridli et al., 2000). The production of such tailored thickness materials has resulted in over $2.5 billion (2016) in combined industry sales (Mubea, 2018). As automakers begin to adopt the manufacturing practices traditionally reserved for steel such as tailor rolling/welding with greater enthusiasm for vehicle light weighting, there exist an opportunity to expand the material database to extend beyond the traditional aluminum alloys found in current production. High strength aluminum alloys, i.e. 7xxx-series, are ideal for structural automotive applications due to their high specific strength; however, they have limited room temperature formability. Hot stamping, another manufacturing practice used by the steel industry, can be used to form these high strength materials. The combination of tailoring the thickness of a sheet material and hot stamping provides an opportunity for significant weight saving within an existing manufacturing footprint. This paper explores the potential and challenges of this approach when applied to structural body-in-white components. The methods for tailor rolling, tailor welding and hot stamping are described and applied to the production of a 7075 aluminum alloy B-pillar. The results are discussed in terms of feasibility and weight savings."

Jan 1, 2018

By G. H. Gale, M. A. F. Fedikow, L. B. Dabek

Rare earth element (REE) data are reported for ores, sul?de-bearing rocks and host rocks from massive sul?de deposits and barren sul?de facies iron formations in Proterozoic volcanic rocks of the Flin Flon-Snow Lake area, Manitoba. Some of the rare earth elements (e.g., Eu), are selectively leached in zones of intense alteration and redeposited together with the sul?des and silicatesin the uppermost parts of the alteration zones and at the rock-water interface. Chondrite normalized REE pro?les of layered sul?de ores and exhalites proximal to the deposits typically have positive europium anomalies and are enriched in light REE. In contrast, barren sul?de facies iron formations exhibit negative or ‘normal’ Eu pro?les. REE data are useful to explorationists in determining the presence of ‘off-hole’ metal-bearing sul?de zones, in distinguishing metal-poor sul?dic layers related to ‘economic’ hydrothermal activity from barren sul?de facies iron formation and in some instances as a means of establishing ‘ore-equivalent’ strata.

Jan 1, 1997

By G. H. Gale, M. A. F. Fedikow, L. B. Dabek

Abstract-Rare earth element (REE) data are reported for ores, sulfide-bearing rocks and host rocks from massive sulfide deposits and barren sulfide facies iron formations in Proterozoic volcanic rocks of the Flin Flon-Snow Lake area, Manitoba. Some of the rare earth elements (e.g., Eu), are selectively leached in zones of intense alteration and redeposited together with the sulfides and silicates in the uppermost parts of the alteration zones and at the rock-water interface. Chondrite normalized REE profiles of layered sulfide ores and exhalites proximal to the deposits typically have positive europium anomalies and are enriched in light REE. In contrast, barren sulfide facies iron formations exhibit negative or ‘normal’ Eu profiles. REE data are useful to explorationists in determining the presence of ‘off-hole’ metal-bearing sulfide zones, in distinguishing metal-poor sulfidic layers related to ‘economic’ hydrothermal activity from barren sulfide facies iron formation and in some instances as a means of establishing ‘ore-equivalent’ strata.

Jan 1, 1997

By V. A. Cooney

Introduction For the compliment paid me by the Institute&apos;s kind invitation to speak this afternoon, I am very grateful. For the astuteness of your officers in determining that encouragement should be given, through the medium of a paper, towards accident prevention in coal mines, the coal industry cannot but be grateful. Some day, and let us hope soon, a more developed paper may supersede this one. In the meantime, if some knowledge of what one coal field has been able to accomplish, even in the initial stages of its effort, will induce other fields and other sections of the mining industry to launch similar experiments, much good will result and a more developed dissertation on the subject will make its appearance.

Jan 1, 1946

By Maciej Wrobel, Joerg Hammerschmidt, Dana Nurgaliyeva, Alexandros Charitos, Jochen Guentner

"Smelting of copper concentrates in the flash smelter generates a flue dust stream that contains a substantial amount of copper and accumulates more than half of the arsenic input to the smelter. In view of its high copper content flue dust recirculation to the flash smelter is common practice. Globally traded copper concentrates are affected by ever increasing arsenic contents and cause an increasing circulating arsenic load in flash smelter operation. Control of the arsenic level in the smelter slag becomes a challenge. This interaction of arsenic loaded copper feedstock, need for flue dust recirculation and slag quality control call for possibilities to reduce the arsenic load of the recirculated flue dust stream.The technology of partial roasting is known from pre-treatment of copper concentrates before smelting, and gold concentrates before cyanide leaching, to remove the harmful element arsenic. The partial roasting technology can be adapted for use in the purification of the flue dust. A major challenge for flue dust treatment is its extremely fine particle size compared to usual concentrates. For this reason Outotec developed a new process, which allows handling of such fine flue dust. This process solution provides an efficient possibility to reduce the arsenic burden in copper smelter operations.The suggested process aims at reducing the arsenic load to the smelter by treating the flue dust prior to recirculation to the smelter. The presented results are based on test work in the Outotec R&D-centre in Frankfurt. It is possible to remove 80-85% of the contained arsenic and to collect it in an arsenic trioxide residue with a concentration above 90%. The final off gas contains SO2 from decomposition of sulphates that are contained in the flue dust. The off gas stream is relatively small. We assume that it is possible to combine the off gas stream with other smelter process gas streams and to treat it in an existing sulphuric acid plant. Coal is used as fuel and as reductant to reduce pentavalent arsenate to trivalent arsenite. Arsenite can be kept in gas form at temperatures above 450°C. This permits separation of a calcine stream with arsenic levels of 0.2 – 0.3%, which is recirculated to the furnace.Outotec has a wide range of roasting testing facilities from lab-scale to pilot-scale. Outotec has both capability to modify and adapt technology to specific ore or concentrate requirements, but also the necessary infrastructure in its research centers in Frankfurt and Pori to do appropriate validation tests in lab and pilot scale size plants."

Jan 1, 2016

By N. Hmidi, T. Yalcin, M. Papadakis, B. Hilscher

Mill tailings, containing iron sulphides in particular, pose an environmental concern since they constitute a potential source of acid mine drainage which can damage vegetation, harm soil and living organisms, and contaminate groundwaters. Proper disposal of acid generating tailings is therefore an important issue that must be addressed and resolved in a satisfactory manner. Placer Dome Canada operates a 4000 t/d gold cyanidation facility at Musselwhite mine, in northwestern Ontario, where the mill tailings have been classified as acid generating. This study was conducted to explore the effectiveness of froth flotation in removing the sulphide minerals from these tailings and producing a low-sulphur, non-acid generating material that could serve as a capping material for previously deposited tailings. Laboratory semi-batch flotation tests were carried out in accordance with an experimental design procedure, and a computer simulation program was developed to facilitate the evaluation of flotation performance. In this investigation, pH, collector concentration, and airflow rate were considered as the relevant flotation variables, and their effects were examined both experimentally and by simulation. Results have demonstrated that flotation can successfully desulphurize the Musselwhite mine tailings and render them non-acid generating.

Jan 1, 2004

By Y. Guglielmi, C. Gout, P. Henry, P. Dick, C. Nussbaum

For a decade, observations and experiments conducted in underground environments worldwide (mines, underground research laboratories - URL) made it possible to bridge the scale gap between laboratory scale and large scale faults. Indeed, underground rock laboratories allow developing decameter scale relatively well constrained experiments at the smallest distance from the hypocenters. URL’s experiments allowed developing new monitoring technologies coupling pressure-strain-seismic measurements and reproducing complete earthquakes sequences analogous to natural ones. They also allowed exploring past movements of faults and sometimes also paleofluids in three dimensions and characterizing different fault architectures and hydromechanical properties in unaltered conditions. This is particularly important in the study of faults affecting clay formations which could not be observed at the Earth’s surface because of the high alteration. Here we show how examples from the Mont Terri (Switzerland) and Tournemire (France) The URLs may help in (i) defining the concepts of fault architecture in shales, (ii) estimating fault hydromechanical properties from field decameter scale experiments. Some key results are that faults which are critically stressed or at the rupture limit can reactivate for stresses variations within the range of those produced by shallow underground excavations, and that slight micrometer-to-millimeter scale reactivations may lead to large factor-of-10-to-1000 permeability increases. Such promising results show that URL’s experiments may bring new insights on some key processes that control the relations between fault stability and permeability evolutions in very permeable layers.

Jan 1, 2015

By Bill Shand

"Placer Dome - Campbell Mine is a gold mine located at Balmertown in the Red Lake District of North Western Ontario. During the last 50 years, the mine has produced over ten million ounces of gold.A change in ball mill grinding media was made in August 1998 from 1.5” diameter forged balls to 1.5” diameter, 18% chrome balls. This was done to reduce grinding media consumption and to potentially help flotation performance.A marked ball test done in September-October 1999 showed that, of the alloys tested, 18% chrome was the optimum for the ore at Campbell Mine. The test showed that consumption of chrome balls should be 3 times less than forged balls.In December 1999, the ball size was increased from 1.5” to 2” in an effort to reduce the amount of oversize rock discharging from the ball mill. This change in size was successful.Grinding media consumption for the ball mill decreased 73% from 1.20 kg/tonne before the use of chrome balls to 0.327 kg/tonne after the use of chrome balls. This clearly indicates that, for the ore at Campbell Mine, there is significant savings in grinding media by using chrome.Grinding ball costs were reduced by 59% from $O.88/tonne of ore milled to $0.36/tonne of ore milled representing a saving of $298,000 per year. This also clearly indicates that using chrome balls is a benefit at Campbell Mine.Test work to show that chrome grinding media is beneficial to flotation has been inconclusive so far but is still ongoing.No tests have been done to see if there would be a benefit with an even higher chrome percentage in the grinding media. Test work in this area is also planned for the future"

Jan 1, 2001

By Graham Holmes, John Starkey

"The Kinross Kubaka Project is a gold mine located in the Russian Far East. The grinding circuit, comprised of a 6.1 m diameter x 2.74 m long SAG mill and a 4.1 m diameter x 5.5 m long secondary ball mill in closed circuit with cyclones, was built using SAG Power Index and Bond Ball Mill Work Index testing to determine the grinding energy requirements. Extremely cold climatic conditions and the need to keep heated space and capital costs to a minimum, dictated a grinding circuit with no in-circuit crusher and no conveyors external to the mill. High energy requirements for both the SAG mill and the ball mill were correctly predicted and have allowed grinding production tonnage forecasts to be met. Design test data and production results are given.INTRODUCTIONIn 1995 Davy International Canada, now Kvaerner Metals E & C, was commissioned as the Engineer and Project Manager for the Omolon Gold Mining Company, to design and construct a gold extraction plant for the Kubaka gold deposit, located in the Russian Far East. This deposit had been studied extensively in Russia during the exploration phase and a Feasibility Study was completed in 1993 by Kilborn who visited the site twice during that year to inspect facilities and to take metallurgical test samples. More samples were taken in 1995 to check ore hardness variability, as part of the final design program by Davy.The client’s objective in designing the Kubaka grinding circuit was to achieve design tonnage at all times, even when milling the hardest ore zones in the deposit. Since the samples taken in 1993 were taken as composite samples, it was necessary to take additional samples in 1995 to determine the extent of the variability. Six samples were sent to Canada for SAG Power Index (SPI) testing. Five of these were combined as a composite open pit sample, while the sixth sample was taken from the site adits as a composite sample to represent undergound ore. These two composite samples were tested to determine the MacPherson Autogenous Work Index for comparison with the SPI values."

Jan 1, 2001

By Oy Leuangthong

The McMurray formation in the Athabasca oil sands deposits of Northern Alberta is part of the world?s second largest proven crude oil reserves. The formation is characterized by stratigraphic layers that correspond to three different depositional environments: Marine, Estuarine and Fluvial facies. Resource estimation for oil sands has traditionally relied on polygonal and inverse distance schemes. These techniques are simple and straightforward in practice, but they do not permit reliable uncertainty assessment. This paper describes the modeling of the McMurray formation using modern geostatistical techniques. Geostatistical modeling should be performed within homogeneous geological facies. The methodology for geostatistical simulation within each of the identified facies involves: (1) assessing the most appropriate stratigraphic transformation for optimisation of the correlation structure, (2) determining representative distributions with declustering and debiasing techniques, (3) modeling spatial continuity of the bitumen grade, fines grade, water saturation and other petrophysical variables, (4) performing estimation and cross validation as checks against simulation results, (5) performing simulation for uncertainty quantification of bitumen and fines grade, and (6) model checking of simulation results against the input data and comparisons against the kriged models. These steps are described in detail. The application of these models for uncertainty quantification in support of resource classification is also discussed.

May 1, 2004

The importance of understanding the behaviour of cemented paste backfill (CPB) within the framework of the effective stress concept is highlighted in this paper. Only through an understanding built on this concept can problems such as barricade loads, the rate of consolidation and arching, be fully understood. The critical importance of the development of stiffness during the hydration process, and its impact on factors such as barricade loads, is used to illustrate why conventional approaches that implicitly ignore the effective stress principle are incapable of capturing the essential components of CPB behaviour.

May 1, 2007

By A. R. Miller, G. Desrivières, T. MacKinnon, H. Bursey, M. C. Bétournay, B. Replogle, D. L. Barnes, P. Laliberté

"A mine production locomotive, the world’s first applied industrial fuel cell vehicle, has been designed and tested in the context of a number of proof-of-concept projects supported by the Fuelcell Propulsion Institute, an international consortium of stakeholders dedicated to facilitate the commercialization of fuel cell vehicles.The locomotive’s simple electric-powered motor and controller system was ideal to study a number of requirements related to fuel cell power application: hydrogen power plant operation, underground hydrogen use, risk and regulatory requirements, production performance versus the conventional battery- powered locomotive version under measured duty cycles and production requirements, power plant design improvements for other fuel cell vehicles, and cost benefit aspects.This article will focus on the design and testing aspects of this project which has led to successful performance demonstrations of the vehicle under surface and underground conditions at two mines. It will also present information on the creation of a safe, reliable, and efficient power plant that fulfilled its design objectives, including longer productivity time for a given vehicle fill-up."

Jan 1, 2004

By Ian McC. Stewart

"Seam gas flow in coal mines takes place through a medium which has both capacity and resistance and can therefore be expressed in terms of the basic diffusion equation, provided that the characteristics of the system can be adequately described. It may be possible to lump the variations from point to point in a seam together as an effective diffusivity. The paper discusses the characteristic flow-time patterns for various types of openings and the particular features of coal and seam which influence the diffusivity.Two field experiments are described in which gas make to a heading and to a borehole were measured in a mine for which considerable data on coal sorption properties were available. Incremental gas flow measured from the borehole experiment predicted the actual flow from the heading measurements remarkably well. The effective permeability adjacent to the face was much higher than expected from the properties of the coal. The incremental flow measurements to a horizontal (in-seam) borehole showed a striking picture of advancing 'relaxation' behind the face which is not discernible by other experimental means."

Jan 1, 1971

By T. Bhambhani, D. R. Nagaraj

"Ultramafic Ni ores present significant challenges in processing in that both recoveries and grades are not satisfactory, due to the presence of Mg silicates in large amounts. Significant quantities of xanthates and CMCs are generally used for their recovery by flotation. Additionally, given that some of these ores are processed under acidic conditions, CS2 generation due to xanthate decomposition presents some safety hazards. Technology to replace xanthate has been developed for which the safety and health issues are absent. Collector S-10294 shows significant improvements in Ni and overall S recovery at a dosing rate of one half that of xanthate. New polymeric modifiers have also been developed that help reduce the Mg content of the concentrates at very low dosages. The reagents are custom designed for use in normal or hypersaline water, and acid or alkaline conditions.INTRODUCTION The use of xanthates in sulfide mineral flotation is reported to have started as early as 1925 (Nagaraj 2005). The reagent is now ubiquitous in the mining industry, accounting for 40-50% of total collector consumption. In recent years, the development of more selective reagents has rendered xanthates largely obsolete in Cu flotation. However, xanthates continue to be sold in large amounts in the Au, PGM and Ni flotation industry, where bulk sulfide flotation is required. The low cost and easy availability is the largest driver for the use of xanthates in the minerals industry. Of particular interest to this study is the use of xanthates in the flotation of Ni sulfide ores. About 60% of the world’s annual nickel output is obtained from sulfide Ni ores (Hoatson, 2006). A strategically important category of these ores is the ultramafic hosted sulfides, such as those of Western Australia and Canada. These ores are characterized by low Ni grades (<1%), with the Ni minerals being pentlandite, violarite, millerite and mackinawite, and gangue minerals comprising an array of altered Mg silicates, mostly serpentines. The challenges associated with treating these ores are well documented (Eltham et al. 1973; Claridge et al. 1975). One challenge is that Ni recoveries from these ores are lower. This has been attributed to the increased pulp viscosity, as discussed in detail by Vasudevan et al., 2010. Additionally, Mg silicates tend to report to the concentrate in large quantities, which is problematic for two reasons: a) concentrate dilution, and b) the high melting point of Mg silicates tends accelerate wear on the refractory lining of smelters. This has been attributed to network transport to the froth phase via bubble flux and entrainment (Patra et al, 2010)."

Jan 1, 2012