Search Documents

By Limao Zhang

This paper presents a novel model to assess the risk of adjacent buildings in tunnelling environments based on Extended Cloud Model (ECM). ECM is an organic integration of Extension Theory (ET) and Cloud Model (CM), where ET is appropriately employed to flexibly expand the variable range from [0, 1] to (-8, +8), and CM is used to overcome the randomness and fuzziness during the gradation of evaluation factors. The risk level of a specific adjacent building is assessed by the correlation with the cloud models. A confidence indicator ? is proposed to illustrate the rationality and reliability of evaluating results. Ten buildings adjacent to Wuhan Metro Line Two (WMLT) are randomly chosen among hundreds of adjacent buildings for a case study. Results have proved to be consistent with the actual situation. Compared with other traditional evaluation methods, ECM has been verified to be a more competitive solution with high calculation accuracy, wide adaptability, as well as simplified computer programming. There are no stringent requirements on the quantity of training data during the modelling process, and the original data can be directly entered into ECM without a normalization procedure, avoiding the potential information loss. ECM can be offered as a decision support tool for the risk assessment in urban tunnelling construction and worth popularizing in other similar complicated projects.

Aug 1, 2013

By W. Curlook, L. M. Pidgeon

THE PURPOSE of this investigation was to study part of the ternary system Co-Fe-S. Jensen ( 1) established the solubility limits of sulphur in pyrrhotite. The compound with 61.7 per cent Fe, corresponding to a formula Fe12S13, was found to melt congruently at l,192°C. Hulsmann and Weibke(2) determined the Co-S phase diagram from O to 35.2 per cent S. The solubility limits of sulphur in the com-pound Co(l-x)S were not determined. The initial object of the present in-vestigation was to determine the composition at which the compound Coci-xiS melted congruently. Once this was ascertained, it was decided to investigate the ternary system Co-Fe-S from the region of 100 per cent Co(1-x) S to the region of 100 per cent Fe12S13.

Jan 1, 1953

By B. Dubreuil, J. -M. Lalancette, D. Lemieux, C. Chouinard

The extraction of gold and silver has been examined via the use of mixed halogens: chlorine and bromine. The reaction was performed in a brine of sodium chloride with a small amount of sodium bromide at 40-50°C, in an atmosphere of chlorine, at atmospheric pressure. The process takes advantage of the very high reactivity of bromine towards gold, while the higher oxidation capacity of chlorine leads to gold chloride as end product with recycling of bromine. Fast reaction rates are observed along with gold recovery at the level of 95%. Chlorine-consuming common elements are removed prior to chlorination.

Jan 1, 2011

By Chantale Doucet

L?utilisation du remblai en pâte dans les exploitations en vrac est de plus en plus importante. Puisque la technologie existe pour fabriquer du remblai en pâte sans construire une usine coûteuse, il est maintenant possible d?élargir le domaine d?utilisation du remblai en pâte pour y inclure des gisements filoniens où le besoin annuel de remblai est moindre. Dans certains cas, l?utilisation du remblai en pâte pourrait permettre de réaliser d?importantes économies telles que la réduction de la dilution, la stabilité des ouvertures, la récupération d?une plus grande partie du minerai par la réduction de la taille des piliers et l?entreposage de moins de résidus à la surface. L?ampleur des économies est parfois difficile à chiffrer mais il est tout de même important d?en tenir compte lors de la décision d?utiliser du remblai en pâte puisque ce sont souvent ces économies qui seront déterminantes. Différentes méthodes d?extraction avec remblai en pâte appliquées aux mines filoniennes seront présentées. Des défis et les solutions reliés à l?utilisation du remblai en pâte à la Mine Doyon seront discutés.

Oct 1, 2001

By F. M. Doyle, G. Sidhu, A. J. Dussault, A. Raygani

There is a growing demand for rare earth metals for use in high strength permanent magnets, most notably Nd2Fe14B. Rare earth metals are extremely reactive, with reduction potentials around -2.5V SHE, and are conventionally produced by molten salt electrolysis. The current work was done to investigate an earlier report of electrodeposition of a neodymium ferroalloy from aqueous solution, to determine whether this approach could be an environmentally and economically competitive commercial approach for producing feedstock for permanent magnets. Such a process would be analogous thermodynamically to the Castner- Kellner process, in which aqueous sodium chloride brine is electrolyzed in cells with mercury cathodes. Metallic sodium forms an alloy (amalgam) at the cathode, thereby lowering the activity of the metallic sodium significantly below unity and making the reduction potential of sodium significantly less negative than the standard reduction potential. Here we report the effects of Nd/Fe ratio in the electrolyte, current density, temperature and two different complexing agents, glycine and cysteine, on the composition and morphology of the electrodeposits, along with current efficiency. The energy needed to produce neodymium as Nd:Fe alloys by aqueous electrodeposition was compared with values estimated for production by molten salt electrolysis and the thermodynamic energy requirement.

Jan 1, 2014

By C. Bergstrand

"Precipitation of gypsum and the formation of scale may pose a serious challenge in the leaching of several minerals. As an example, precipitated gypsum may form scale in the machines increasing the need for maintenance. Alternatively, it may encapsulate precious elements, i.e. gold and lower the recovery during subsequent leach processes. In this work we explore how different biopolymers modify the rheology of gypsum at three different pH levels at ambient and elevated temperatures. The ability to disperse gypsum vary with temperature, pH and biopolymer. It is also inversely related to the scaling potential. Measurements of the zeta potential as a function of increasing amounts of biopolymer reveals that the magnitude of the zeta potential changes in the presence of biopolymer, and so does the ability to disperse the gypsum suspension. Similar results with hematite will also be discussed. The methodology and results may aid in the selection of additives used in mineral processing applications where scale pose a problem.INTRODUCTION Processing of refractory gold ores normally involve either atmospheric or oxidation under pressure in order to convert sulfides to oxides (Weir, King, & Robinson, 1986; Weir, Robinson, & King, 1986). This conversion facilitates leaching of gold (and silver) in normal CIL processes. During oxidation, sulfides are converted to sulfates. Normally, there is an abundance of calcium ions in the process water, either released from the ore or added as lime to adjust pH for the CIL process. Precipitation of calcium sulfate, or other compounds (calcium carbonate, jarosite, hematite) is a way to remove gangue minerals from the solution entering the CIL circuit (Ji, King, Fleming, & Ferron, 2010). Precipitation may also cause challenges in the process as gold (or other valuable elements) may become encapsulated in gangue. (Beauchamp, Choung, & Xu, 2006). In addition to precipitation, the precipitated gangue minerals may solidify and form scale in the processing equipment. Recently, Lauten and Kluck (2016) found that dispersants used as scale inhibitors to prevent encapsulation of gypsum did not modify the solubility of gypsum. In the utilised model system, similar amounts of gypsum precipitated with and without dispersants. Instead, it was found that the dispersants evaluated as scale inhibitors reduced the yield stress of gypsum suspensions. The reduced yield stress was associated with a reduced tendency for gypsum particles to agglomerate and form scale."

Jan 1, 2017

By Ian R. Morrison

"Abstract - The Izok Zn-Cu-Pb-Ag volcanogenic massive sulfide deposit is located 265 km south of Kugluktuk (Coppermine), Nunavut Territory, Canada, in the west-central Slave structural province. The Izok deposit is owned 100% by Inmet Mining Corporation and represents one of the largest undeveloped zinc-copper resources in North America. The Izok deposit is hosted within and near the top of a thick sequence of predominantly felsic pyroclastic rocks of late Archean age. The hanging-wall stratigraphy includes additional felsic volcaniclastic rocks, andesitic and basaltic flows, thin sulfide-rich iron formations, and turbiditic sedimentary rocks. The felsic volcanic rocks are intruded by intermediate dikes and sills, followed by gabbroic dikes and sills. Both intrusive suites are interpreted to be volcanic feeders to the overlying flows. All lithologies are subsequently cut by younger, irregular, granitic pegmatite and diabase dikes. The volcanic and sedimentary rocks are regionally metamorphosed to pyroxene hornfels grade. The massive sulfides occur within a large (kilometer-scale) Na-depleted sericitic alteration zone. The immediate footwall and hanging-wall rocks to the deposit are characterized by zones of muscovite- biotite-sillimanite, lesser chlorite-biotite-cordierite, and locally intense silicification and sodium metasomatism. All lithologies have been affected by younger Ca-metasomatism. As currently defined, the Izok deposit comprises a cluster of five complexly zoned composite lenses: the Northwest, North, Central West, Central East, and Inukshuk lenses. The first four lenses are amenable to open-pit mining, whereas the Inukshuk lens will require underground development. The total indicated mineral resource presently stands at 16.5 million tonnes with a grade of 2.2% Cu, 11.4% Zn, 1.1% Pb, and 60 g/t Ag. Inmet Mining Corporation is presently reviewing the economic feasibility of developing the property."

Jan 1, 2004

By Shichang Liu, Hongli Jia, Zhaolian Wang, Maotang Liu, Ltd. Shandong Huate Magnet Technology Co., Fengliang Liu

"Introduce and promote a latest technology and equipment for magnetite. It’s featured of purifying concentrate, lowering tailing grade, high concentrate recovery rate and stable operation. HUATE® New Style Elutriation Electromagnetic Separator is an equipment to obviously upgrade magnetite. The slurry is fed into separation area through feeder. Generated by excitation coil, the working magnetic field distributes specially in separation area. Under the combined effect of the background field, excitation and demagnetic field and gravity, the mineral particles float downwards in the form of magnetic chains, and interact with the rising water. The gangue, non-magnetic particles, lean intergrowth,etc will be discarded as tailing via overflow tank and pipe. While the magnetic will be discharged from concentrate pipe. Its grade is 2%-10% higher than that of traditional magnetic separation equipment. It adopts the technologies of transformer oil cooling, alternative and uniform pulsation magnetic field controlling the tailing grade, larger drum feed-in device, more uniform umbrella scattering discharge and stabler output current, and realizes lower coil temperature raise, stabler magnetic field, more uniform discharge, effective isolation of weak-magnetic area from non-magnetic area, more obvious upgradation and recovery rate and lowering tailing mFe%. It’s more suitable to purify and thicken the high grade and ultrafine iron powder. Compared with traditional elutriation equipment, it adopts new technologies in removing impurities, operation, large-scale, process simplification, water-saving, remote control, etc. It optimizes the comprehensive beneficiation index, expands its application scope, reduces resource wastes and increases economic benefits.INTRODUCTIONMagnetite accounts for a comparatively great proportion in various iron resources. As it’s a kind of strong magnetic mineral, we must adopt the weak magnetic separation equipment in magnetic separation process to realize removing Si and lowering impurities. While it cannot do very well to use the common weak magnetic separation equipment in the final cleaning to remove Si and lower impurities. At present, the plants, adopting single magnetic separation process to realize cleaning and removing Si and lowering impurities, are in the minority. Most magnetite plants adopt the flotation separation process to remove Si, lower impurities and purify the concentrate. Though with stable indexes and high Fe recovery rate, the flotation process is very complicated, high-cost and with lots of environmental pollution. If adopting the weak magnetic separation equipment can realize removing Si, lowering impurities and the final cleaning, the magnetic separation process should be the primary choice."

Jan 1, 2016

By G. Marchand, R. H. Hay, E. C. Pearson

"AbstractA polishing .technique is described together with two anodic etching methods for aluminum and its alloys. Some of the optical and structural characteristics of the film formed by •these etching methods are discussed and it is shown to what degree these properties of the film are related to the crystallographic orientation of the metallic substrate. Applications to the study of recrystallization and twinning phenomena and to the study of plastic deformation, banding, and texture estimation are discussed. Micrographs are shown .to illustrate the manner in which the technique is particularly well suited to the study of such phenomena.IntroductionThe physical metallurgist is constantly faced with the problem of polishing and etching of metallic sections. Mechanical polishing is tedious, time consuming, and not applicable whenever a surface entirely free from plastic deformation is required. Etchants are generally required to reveal the grain structure in order to determine its size, shape, and regularity, or to bring up constituents. In the case of aluminum, the .most common etchant to reveal grains is a mixture of three acids: HC1, HN03, and HF. This etchant is fairly satisfactory on certain alloys and for certain metallurgical conditions but in general fails to give a good definition of the grain on castings, on highly alloyed products, and whenever the grain is smaller than 100 microns in diameter. Besides size and shape, a grain, or crystal, has an orientation and may be endowed with several types of imperfections."

Jan 1, 1952

By J K. Irwin

The authors discuss the application of drum and friction hoists under modern conditions and give four examples of friction hoists proposed for various applications. The paper concludes with a summary of the advantages and limitations of friction hoists relative to drum hoists. Introduction T H~ introduction of the multiple-rope friction hoist m the late 1940's has complicated the se-lection of the right hoist for a given job. Once such considerations as rope safety factor, drum to rope ratio, hoisting distance, tons per hour and/or service duty have been decided upon, the selection of a drum hoist is relatively simple. We now ask our-selves "which hoist -drum or friction? (See Figure 1 and Figure 2). When a friction hoist is a possibility we are immediately concerned with how many ropes to use, whether to hoist balanced or counter-balanced, whether a friction hoist will be flexible enough for the application and, of course, what the relative costs will be.

Jan 1, 1964

By James K. B. Booth

The natural crustal abundances of the principle metals of commerce are examined in relation to production and prices for each metal. Two factors, the abundance x price ratio (BP factor) and abundance/production (B/T factor) are listed for each metal. Ideally, for these desirable commercial metals, each factor should be a constant and the same for all metals; comparing the divergences for the full list of metals allows conclusions to be drawn on the relative degree of natural availability of each metal and the ease or difficulty of winning the metal from the earth's crust. Plotting the two factors for each metal over the past decade of steady industrial usage illustrates the anomalous position of copper and, to a lesser degree, molybdenum and it is concluded that over the long term the price of copper will continue to rise steeply. Possible future prices for copper are examined and a suggested preferred order of ranking of the metals as exploration targets would be copper, nickel, tin, zinc, silver, molybdenum and lead, for the near term, with molybdenum possibly increasing its ranking in the list within the next decade.

Jan 1, 1971

By Claudio Acuña, Sergio Romo, Gerardo Fuentes

The leaching kinetics of a zinc concentrate in autoclave reactors were studied. A sample of concentrate from Bolivia, with typical mineralogical characteristics of the Andes region, was used. A concentrate containing 49% zinc and 145 ppm of silver from Minera Viacha was characterized chemically and mineralogically (atomic absorption, X-ray diffraction, and SEM microscopy) and tested in bench scale reactors. Two types of autoclave batch reactors were used at 40 bars of oxygen pressure and three levels of temperature (150°C, 200°C and 250°C). The solid to solution leaching ratio was 1:10 (10% sulphuric acid concentration). The effect of the particle size of the concentrate on the leaching kinetics was studied (P80: 145 and 45 µm). Iron from the leaching solution was removed by precipitation by increasing the pH in order to generate a clean solution for zinc electrowinning. The zinc solution was used to evaluate the feasibility of cathode production at the laboratory scale. Zinc extractions with higher liberation (P80 = 45 µm) reached up to 98%. Ground concentrate with finer sizes resulted in agglomeration and the use of dispersing agents did not improve slurry mixing. The leaching solution contained 55 g/L zinc and 7 g/L iron; it was purified by precipitating iron. The precipitation was evaluated using sodium hydroxide and ammonium hydroxide. In the first case, a colloidal suspension of ferric salts was formed while in the second case, different iron compounds were precipitated. The precipitate obtained with ammonium hydroxide had better filtering properties. Electrowinning was carried out using two types of cathodes (stainless steel and aluminium) and solutions purified with ammonium hydroxide. Zinc cathodes formed on stainless steel presented a better physical quality than those formed on aluminium.

Jan 1, 2015

By Farzaneh Abedini, Narain Hariharan, Lucas C. McFarlane, Nikolas A. Romaniuk, Tiffany Thayne

The use of dewatered mine tailings as backfill material (commonly referred to as ‘paste’ backfill), is the most practiced form of backfill in Canada providing significant environmental benefits by reducing the size of external tailings facilities and improved economics through enhanced resource recovery. Paste backfill operations reuse filtered mine tailings with a cementitious binder and water to create a slurry that is hydraulically transported to refill underground stopes, later forming a structural network of cemented tailings in the mine stopes. Unlike typical structural applications that utilize General Use (GU) Portland cement; modern paste backfill operations maximize strength performance by blending Portland cement with ground granulated blast furnace slag (GGBFS) or other supplementary cementitious materials (SCMs). GGBFS and other SCMs offer key performance benefits and carbon reductions; however, the availability of these SCMs is rapidly dwindling in today’s carbon-constrained economy. This paper examines the development of an alternative binder system that provides similar performance and carbon reduction to that of GGBFS for mine backfill operations. The binder utilizes the chemical reaction between a reactive source of aluminosilicates and available calcium from calcium oxide or calcium hydroxide to replace between 50 to 100% of GGBFS. The performance of the binder is examined with insights into the hydration mechanisms that generate mechanical strength in the cemented paste network. Paste backfill slurries require precise engineering to create a material that maintains flowability during pipeline transport and generates enough strength to meet operational targets once placed in the stopes. Engineering of such slurries requires large amounts of water to be added to the binder-tailings matrix, far exceeding the typical water to binder ratios used in concrete mix designs. This characteristic of paste backfill warrants great emphasis on understanding the hydration mechanisms of the binder used in the paste backfill system. GU cement is typically composed of 50-70% tricalcium silicate and 15-30% dicalcium silicate.  The hydration mechanisms of these compounds consume 4 to 6 units of water to mineralize into calcium silicate hydrate cemented phases that result in compressive strength development. Cementitious aluminate and aluminosilicate phases make up 5-20% of GU cement and aid in secondary performance characteristics such as set time. Certain calcium aluminate hydrate phases such as monocarboaluminate and ettringite mineralize 10 to 32 units of water into their crystalline structure. Hydration products such as ettringite are traditionally avoided in construction applications due to their propensity for volumetric expansion after cement setting, leading to micro-fissures and subsequent strength degradation (known as ‘sulfate attack’). This paper proposes that such hydration products benefit the strength development in paste backfill slurries with the aforementioned characteristics due to their greater potential to mineralize free water. The newly developed calcium aluminosilicate binder is designed to replace 50-100% GGBFS or other SCMs used in paste backfill systems and meet operational strength requirements by providing exceptional hydration characteristics through cementitious reactions. Additionally, the aluminosilicates used have a minimal carbon footprint and a secure supply outlook, thereby allowing mine operators access to a low-carbon binder option throughout the mine’s lifespan.

May 4, 2025

By Jas. G. Ross

Introduction Asbestos, a mineral known and used in ancient times, has become an article of commerce only during the life of the older asbestos miners in Quebec. The diversified uses of this adaptable substance are now numbered by the hundreds. Wherever insulation or resistance to heat may be required, asbestos, either by itself or mixed with some other material, may be employed to advantage. Regarded as a curiosity for centuries, it is now in such common use that it is familiar to all. The demand for long fibre for use in the manufacture of textiles and brake-lining, and for shorter fibre for making shingles, paper, and insulation materials, serves to support the industry of mining asbestos-bearing rock and milling the fibre from it in Canada, South Africa, Russia, Cyprus, and the United States. The commercial use of asbestos dates only from 1876, in which year large deposits were discovered in the Province of Quebec, Canada. Prior to that year a small amount of long fibre amphibole asbestos was produced in Italy. Occurrence In Canada In the Eastern Townships of Quebec, along the line of the Quebec Central railway, is an area of serpentine rock. It extends westerly into Vermont and easterly to Gaspe. A part of it, the section from Danville to East Broughton, contains areas in which occur deposits of commercial asbestos fibre of the chrysotile variety. Pits have been opened on some of these deposits at Danville, Coleraine, Black Lake, Thetford Mines, Robertson, and East Broughton. Thetford is distant 68 miles from Quebec city, East Broughton lies 25 miles to the northeast of Thetford, while Danville is 45 miles to the southwest of Thetford.

Jan 1, 1927

Slurry flow, including flow through the charge, through the discharge grates, along the pulp lifters and its discharge from the mill is an important contributor to the efficiency of the grinding process within a SAG mill. Poor transport of finer ground material can adversely affect grinding leading to excess energy consumption and over-grinding of fine material. This paper extends a 1-way coupled DEM-SPH method to three dimensions and applies it to a 1.8 m diameter by 0.6 m long AG/SAG pilot mill. This provides detailed information on the internal flow of slurry within a SAG mill, including the prediction of dry regions and of slurry pooling. Full 3D analysis also allows the pulp flow patterns into and out of the mill via pulp lifter chamber to be investigated.

Jan 1, 2012

By B. F. Haanel

IN the fall of 1929, a paper was presented at the Annual Western Meeting of the Institute entitled The Fuel Research Laboratories at Ottawa and the Scope of Their Investigations. At that time, the equipment of the laboratories had not been completely installed, but the regular routine work was being carried on as usual, and several large-scale investigations were being conducted. It is now five years since that paper was presented, and it seems fitting that a brief description of the investigations which have been undertaken, together with results-especially those which have reference to western Canadian fuels-be presented at this Annual Western Meeting. The coal mining industry of western Canada has, within the past few years, suffered many unfortunate vicissitudes. The replacement of coals by oil, for bunkering ships, for operating railway locomotives, and for heating, has weighed heavily on the coal mining industry of British Columbia and Alberta generally, but more particularly in the Crowsnest Pass area and Vancouver-and hydro-electric developments have also left their impress. With a full appreciation of these conditions, the Department of Mines planned research and large-scale investigations which it was considered would be of the greatest benefit to the coal industry, and the results have amply justified the plans and anticipations. The fact, however, must not be lost sight of, that the application of the findings of certain of these investigations would not have been feasible had not the Federal Government assisted the transportation of coal by the application of railway subventions. These subventions permitted Canadian coals to compete at competitive points with United States coals, and it must be admitted also in this connection that certain of the collieries which have benefitted, both as a result of the railway subventions and the investigations conducted by the Fuel Research Laboratories of the Department of Mines, made special efforts to produce a coal which was capable of competing with the American product, by special preparation at the mines.

Jan 1, 1936

"The outlook for Eastern Canada is decreased coal production and for Western Canada increased production. The market for Western coal is expected to reach 40 million tons per year in metallurgical and thermal-power markets.Technical developments in Eastern Canada include successful methane drainage experiments, modifications to the shearer-loader to improve cutting rates, mechanized mining of a tail-gate stable and mechanical stowage of level brushing. In Western Canada, the most modern equipment is used in mining, beneficiating and shipping coal. Underground hydraulic experiments were started in 1969. The importance of reclamation was recognized and plans have been made to re-vegetate disturbed areas and mine dumps.The Mining Research Centre closed the field office in Nova Scotia and is preparing to open a new field office in Calgary, Alberta."

Jan 1, 1970

By P. Curry, H. G. Stephenson, B. Van Den Bussche

"Three Sisters Resorts Inc. currently owns a2035 acre (824 ha) parcel of land, which previously belonged to Canmore Mines Ltd. Approximately 50% of these lands, that are slated for residential, resort and recreation development, have been undermined for coal in one or more seams.Norwest Mine Services has been contracted by the developer to assess and advise them on any past mining activity that may be potentially hazardous to their development and offer solutions to how these hazards may be mitigated or avoided.The following paper deals mainly with the procedures put in place and accepted by the approval authorities, and the Staged approach to the Investigative Procedure that Norwest follows in the mining assessment and mitigation work for Three Sisters."

Jan 1, 1996

By S. P. Lowe

Introduction In the following pages a general description is presented of the concentrator and cyanide plant of the Hudson Bay Mining and Smelting Company, Limited, at Flin Flon, Manitoba, together with some account of the steps which have led to the adoption of the present practice. For an account of the preliminary test-work and pilot-mill operation, the reader is referred to a recent paper by R. E. Phelan on the History of Flin Flon Mine up to Construction (1). Additional notes may be found in a paper which the writer presented at the Annual Meeting of the Institute in 1930 (2). The first ore was crushed in the present plant on July 1st, 1930, and the first ball-mill was started one month later, on August 1st. Since that time, production has been continuous with the exception of one month lost during a strike in the summer of 1934. There have been no major changes in equipment or methods of treatment since the present plant was built, but many minor changes have contributed to the improvement in results obtained and to the increase in capacity to the large tonnage now being milled. The accompanying flow-sheets indicate the equipment used in the several plants, with the average life and repair cost. As originally built, the concentrator was to treat 3,000 tons per day, but the capacity has been increased to 4,400 tons. The methods adopted to make possible this increase in tonnage will be referred to below. It was the intention to produce two classes of ore: (1) a heavy sulphide, and (2) a disseminated ore. The mill was consequently divided into two sections, each adapted for most efficient treatment of one particular type of ore. However, it was soon found that it would be impossible to mine the two classes of ore separately, so it was decided to treat open-pit ore, which varies greatly in character, in the sulphide section, and underground ore, which is fairly constant, in the disseminated section. This segregation is still maintained.

Jan 1, 1935

By T. H. Etsell, P. Kerr

Over the past 50 years, there have been a number of geological, mineralogical and metallurgical studies carried out on the Clear Hills ironstone deposits in northern Alberta, Canada. Due to the low grade and complex mineralogy, previous metallurgical studies have achieved limited success. After rejecting some of the more ‘conventional’ techniques for iron ore beneficiation, the authors chose to investigate the grain enlargement/iron segregation process for the beneficiation of the Clear Hills ironstone. The segregation reactions for iron have not been explored in as much detail as they have for copper and nickel. Iron segregation roasting involves the addition of a carbonaceous reductant and a chloride transport agent to an iron oxide ore, and heating the mixture to an appropriate temperature. The benefit of this process is that it allows ores in which the value minerals are intimately associated with gangue minerals to be processed in circumstances where conventional iron ore processing techniques are not suitable or capable of upgrading the material. As iron is one of the few elements that can be transported through this process, a clean high purity metallic concentrate can be achieved.Through the use of crucible testing followed by Davis tube magnetic separation, scanning electron microscopy, X-ray diffraction and atomic absorption spectroscopy analysis, characterization of the reaction products has been made with an improved understanding of the reaction mechanism.

Jan 1, 2015