Search Documents

By K. J. K. Weglo, M. U. Savich

"At the Falconbridge Limited, Canadian Nickel Division, Sudbury Operations, we investigated the ""NO NOISE"" ear muffs model NN3-F which is a Swedish product with foam-filled sealing rings (the Hellberg Standard Volume Hearing Protector). It is used extensively at Falconbridge mines in Sudbury.The research which was carried out in the four Falconbridge mines was conducted under three different headings: manufacturer's attenuation data (psychophysical method), clamping force and head size (bizygomatic diameter), and attenuation tests (physical methods) under working conditions.Manufacturers of hearing protectors claim their products offer noise reductions of 23 decibels (NRR) or more, but they fail to point out that this reduction is obtainable only under ideal conditions. The reality of attenuation under working conditions, as several studies have found, is quite different.Methods for using short measurements to determine the noise exposure index, and for controlling muff-wearing habits, were developed at the Elliot Lake Laboratory. Measurements taken at Falconbridge on ""NO NOISE"" ear muffs revealed that they have a practical attenuation of some IO to 13 decibels. It is important to note here that measurements also revealed that clamping force (thus attenuation) was in an inverse relationship with ear muff comfort. Measuring attenuation using noise dosimeters was a difficult job. Not a single surveyor would accept these measurements (physical method) for absolute accuracy. Apart from that, it was impossible to measure, in one shift, more than two work stations. Because of this, we sought a solution: measuring head size and clamping force in relation to actual attenuations.A detailed analysis of the relationship between attenuation and head size/clamping force was done at four mines. Standard deviation ellipses (standard error ellipses) for head size versus clamping force are in close agreement with measurements that were carried out. In order to measure clamping force an apparatus was constructed and a method for measuring suspension system durability is described in Appendices Band C of this report. At the same time we sought to reduce deterioration of ear muffs in mines as well as to put in place a system whereby attenuation can be controlled and improved. The clamping force apparatus can be operated automatically. The proposed control system is quick, simple and efficient . This system is equally applicable in small and large mining operations, and it can be totally automated and the data computerized for audit of the results. This control system is a new step in controlling ear muff attenuation in working environments.From these measurements of NN3-F ""NO NOISE"" muffs it can be concluded that ear muffs are not the total solution to protect the worker from noise.As the results were evaluated folio wing measurement, Falconbridge switched from the NN3-F ""NO NOISE"" muffs to approximately 90% Mark V ""NO NOISE"" muffs and 10% Mark V MSA muffs. These new muffs showed much better head size versus clamping force relationship and can be expected to produce 14 dBA or better attenuation of noise. RESUMEUne étude des casques antibruit ""NO NOISE"" modèle NN3-F, de fabrication suédoise, avec anneaux d'étanchéité en mousse (dispositif de protection contre le bruit ""Hellberg "" pour volume ordinaire)a été effectuée Ii la Falconbridge Ltd. , Division canadienne du nickel aux installations de Sudbury . Ces casques sont largement utilisés dans les mines de la Falconbridge Ii Sudbury.Cette étude aeu lieuen milieu de travail dans les quatre mines de la Falconbridge sous trois rubriques différentes soit: les données d'atténuation du bruit du fabricant (méthode psychophysique), la force de serrage et la taille de la tète (diamètre bizygomatique), et les essais d’atténuation de bruit (méthodes physiques). Les fabricants de dispositifs de protection contre le bruit prétendent que leurs produits offrent une réduction du bruit s'élevant Ii"

Jan 1, 1986

By Tony Robles

"A new process is disclosed for the recovery of gold and/or silver values from activated carbon wherein they are adsorbed as cyanide complexes. A unique chemistry allows the new process to use mill process water containing an inexpensive, non-hazardous compound as the eluant. The new process has an elution period of 5 hours at 98°C. The gold in the eluant can be recovered by electrowinning or zinc precipitation. The new elution process is simple, reliable, and provides an eluted carbon that may not require thermal regeneration before reuse. Retrofitting the new process to existing processes such as Zadra, Anglo, and others will not require significant capital expenditures.IntroductionThe efficient and reliable elution process for gold/silver from activated carbon is a very important process in the gold mining industry. The most common techniques for elution of gold cyanide from activated carbon are the Zadra and Anglo procedures.Specialized elution techniques like the Micron and Acetonitrile processes have not been commercialized to significant extent probably due to relatively complex unit operations and expensive reagents.Important functions of the gold recovery circuit are:Efficiently recover gold/silver from the loaded carbon.Carbon is in good condition for reuse for optimum recovery.The pregnant solution is amenable to electrowinning or zinc precipitation to recover gold/silver from the solution.The whole process to be simple and short to reduce gold inventories.Present Elution ProcessesTable 1 shows some carbon elution processes that are available today. The two main elution processes used in the industry are: (1) the Zadra process, in which hot cyanide solution is circulated through an elution column and electrowinning cells; and (2) the Anglo American Research Laboratory (Anglo) process, consisting of a pretreatment step with caustic cyanide solution, followed by elution with deionized water."

Jan 1, 2000

By Marc R. Laflèche, Suzanne Paradis, A. Shirley Péloquin, Harold L. Glbson, Robin Potvin, Pierre Verpaelst

"The Archean Blake River Group is best known from a central volcanic complex in Rouyn-Noranda. This volcano-tectonic depression, delimited by the Hunter Creek fault to the north and the Horne Creek fault to the south, is interpreted to be a cauldron approximately 20 km in diameter. Its western and eastern boundaries are the Flavrian Plutonand the D'Alembert shear zone respectively. The complex has an exposed stratigraphic thickness of 10.5 km. Two cycles, composed of andesitic units overlain by bimodal, andesite - rhyolite units, are observed in the area, and are, in turn, overlain by an andesitic unit interpreted to be the lower part of a third cycle.The southern sector of the Blake River Group, south of the central volcanic complex, is considered to be outside the limits of the cauldron, but partly contemporaneous with it. The maximum stratigraphic thickness exposed in this area is 4 .6 km. At least two cycles occur in this sector. The oldest unit, a pre-cauldron andesitic to basaltic unit, occurs only in the southern part of the sector. In the north, two partial andesite - bimodal cycles, interpreted as contemporaneous with the cauldron volcanism, are observed.The eastern sector of the Blake River Group, east of the central volcanic complex, apparently overlies the complex. Two units are observed in this sector: a lower bimodal unit and an uper andesitic unit. The bimodal unit is coupled with the uppermost andesitic unit of the central volcanic complex to form a cycle, and the andesitic unit is considered to be the uppermost unit of the Blake River Group. The total exposed stratigraphic thickness in the sector is 2.5 km.The western sector of the Blake River Group, north and west of the central volcanic complex, is interpreted as the lateral equivalent of the complex. Three andesite - bimodal cycles are exposed in this sector, giving a total stratigraphic thickness of9 .5 km. The two lower cycles correspond directly to the central volcanic complex cycles; this correlation is facilitated by two stratigraphic marker units observed on either side of the Hunter Creek fault: the Fish-roe rhyolite flow, east of the Flavrian pluton, and a spherulitic rhyolite lapilli-tuff, west of the Flavrian pluton.Many of the volcanogenic massive sulphide deposits found in the central volcanic complex are spatially and temporally associated with synvolcanic faults, and felsic domes and feeder dykes that are the sites of felsic volcanism in the bimodal units. However, these features also occur outside the central volcanic complex, and the similarities recognized in this work between the complex and the surrounding area suggest that such deposits need not be restricted to the central volcanic complex. The presence of volcanogenic massive sulphide deposits outside the complex confirms this."

Jan 1, 1990

By F. N. Smith

The carbon steel casings of Heat Recovery Steam Generators (HRSGs) in a co¬generation plant were found to have developed cracks that originated on the inside surfaces. The HRSGs receive hot exhaust gases from the primary Gas Turbines (GTs), which are fuelled with pipeline natural gas. The GTs was initially operating without any suppression of nitrogen oxides (NOx). After being in service for about two years, some of the cracks were found to have penetrated right through the 1/4 in. thick casings. The casings are fitted with insulation on the inside (hot gas side). Examination of steel samples cut from the casing walls revealed (i) fine cracks propagating through the steel from the inside surfaces, and (ii) the presence of relatively large amounts of nitrate ion on the inside surfaces. It was concluded that the nitrate ions originated from nitric acid that was condensing on the relatively cool walls of the casings behind the insulation. Nitric acid was formed in the GT exhaust gases by the combination of water vapour (formed from combustion of the hydrocarbon fuel and from moisture in the combustion air) and nitrogen oxides (formed from nitrogen and oxygen in the combustion air).

Jan 1, 2005

By M. Morin

"This paper examines the design issues associated with the integration of mineral processing within underground mining using a total systems approach. It demonstrates conceptual integrated system design options appropriate to a range of geological scenarios. Particular reference is then given to a case study of stoping in narrow base metal veins.The performance of such integrated systems in terms of productivity, economical and environmental criteria is demonstrated by means of simulation. Particular attention is given to the potential benefits to mine waste management. Processing technologies appear to offer genuine potential benefits, while underground mining methods may need to evolve further to facilitate full integration. This paper is based on industry supported research aimed at developing selective and clean underground mining systems. IntroductionTotal systems thinking is simple in principle but complex to implement. The premise is that to achieve optimum effectiveness and efficiency from a system, the complete system must be considered. Using this approach will avoid the situation where the optimization of a localized component of any system results in a negative impact on the performance of the complete system. Take for example the parts manager who reduces inventory costs without consideration of the consequences to the plant. If the plant goes down and a part is unavailable, it would then cost significantly more than the cost of having it in inventory (Ackoff, 1994).A tool for applying total systems thinking toward understanding and analyzing different mineral extraction options is the structured analysis and design techniques (SADT). Originally developed by Ross (1977), SADT is a formal systems engineering methodology (FIPS PUB, 1993) for process and enterprise modelling (Marca and McGowan, 1993). Figure 1 presents a highlevel structured analysis of the traditional or conventional metal extraction process. There are three sequential processes with several arrows entering or exiting each process. In SADT, inputs always enter from the left-hand side and exit as outputs of the process on the right-hand side. Constraints affecting the transformation of inputs to outputs enter the process from the top while resources or mechanisms enabling the transformation enter from the bottom. SADT is a hierarchical decomposition technique and further analysis is undertaken by expanding downward into each process."

Jan 1, 2003

By A. A. Beland, R. J. Dawson, S. Shewchuk

"Shovel buckets, scraper blades, dipper teeth, mine car wheels and hammermills are examples of equipment which require routine maintenance due to abrasion. Service life can be extended by the use 0/hard/acing and buildup materials. Mining and milling applications are described and field welding procedures discussed.A high-stress abrasion test used to select hard/acing and buildup materials/or hammers in a hammermill is described in detail. Field tests of the selected alloys confirmed their performance, and maintenance records showed a significant saving in down time and cost.The relationship between the abrasion resistance of the alloys and their hardness, work hardening, composition and microstructure is summarized. IntroductionLarge volumes of ore are handled daily by the mining industry. The abrasive nature of most ores results in extensive wear to both handling and processing equipment. If such wear is neglected it may cause lost production time and also, in extreme cases, require the complete replacement of expensive equipment. The well-planned maintenance of components subject to abrasive wear by means of buildup materials and hard facing can result in substantial economic benefits. Such benefits can , however, only be realized through the correct choice of welding process, consumables and deposition methods available to maintenance personnel. Hardfacing MethodsHardfacing is applied by a variety of methods; the three most widely used being arc welding, oxyfuel gas and thermal spraying. Table 1 summarizes the major processes used within each method. Filler metals in the form of rod, wire or powder are necessary to fulfill the individual requirements of each process. The filler rods are available in the cast form or, in the case of ductile metals or alloys, as wrought rod or tube. All types are supplied bare or flux covered. Wire is supplied in two forms, drawn flux cored and drawn solid. Powder filler metals are available in many metals or alloys; they may be simple mechanical mixtures or prefused and atomized alloys made to a specific size range and shape for optimum results for each applicable process."

Jan 1, 1980

By B. Lafrance, C. J. Beaumont-Smith, L. R. Jones

"Abstract - The Burnt Timber gold deposit is located in the Paleoproterozoic Lynn Lake greenstone belt of the Trans-Hudson Orogen, Manitoba. The deposit occurs along the Johnson shear zone, and is hosted by enriched and depleted tholeiitic volcanic arc basalts cut by feldspar porphyry dikes. The Johnson shear zone is a regional, belt-parallel structure characterized by the intensification of the regional S2 foliation. At the Burnt Timber deposit, S2 is folded by centimeter- to meter-scale, Z-shaped, F3 chevron folds that have an axial planar S3 crenulation cleavage. Within the 20 to 30 m-wide core zone of the shear zone, S2 and F3 are transposed parallel to S3 and the volcanic rocks are strongly sheared parallel to S3. The presence of a steeply plunging stretching lineation, together with dextral shear sense indicators along both S2 and S3 on horizontal surfaces, suggest that the Johnson shear zone is a dextral transpression zone. Gold was introduced in pyritic, biotitic, and carbonatized mafic volcanic rocks along the core of the shear zone. Mylonitic mafic volcanic rocks contain localized high-grade zones (=10 g/t Au) that differ from wider carbonatized, low-grade zones (<3 g/t Au) by the presence of deformed gold-bearing quartz-pyrite veins. High-grade zones are also associated with swarms of quartz-pyrite veins that cut across sericitized and carbonatized feldspar porphyry dikes, which acted as brittle, competent bodies during shearing. Gold deposition in the high-grade zones was controlled by the channeling of hydrothermal fluid along the core of the shear zone during shearing of the volcanic rocks, and brittle fracturing of the porphyry dikes. Sommaire - Le gîte aurifère de Burnt Timber est situé dans la ceinture de roches vertes Paléoprotérozoïque de Lynn Lake dans l’orogène Trans-Hudsonien, au Manitoba. Ce gîte est situé le long de la zone de cisaillement de Johnson et est encaissé dans des basaltes tholéiitiques d’arc enrichis et appauvris recoupés par des dykes porphyriques. La zone de cisaillement de Johnson est une structure régionale parallèle à la ceinture de Lynn Lake caractérisée par une intensité accrue de la foliation régionale S2. Au gîte de Burnt Timber, S2 est affectée par un plissement F3 en chevrons en Z d’échelle centimétrique à métrique associé à un clivage de crénulation de plan axial S3. Dans la zone centrale de 20 à 30 m de largeur au sein de la zone de cisaillement, S2 et F3 sont transposés parallèlement à S3 et les roches volcaniques sont fortement cisaillées le long de S3. La présence conjointe d’une linéation d’étirement à forte plongée et d’indicateurs cinématiques dextres sur les surfaces horizontales S2 et S3 suggère que la zone de cisaillement de Johnson est une zone transpressive dextre. L’or a été mis en place dans des volcanites mafiques altérées en pyrite, en biotite, et en carbonate au coeur de la zone de cisaillement. Les roches volcaniques mylonitiques présentent des zones aurifères locales à haute teneur (=10 g/t Au) qui diffèrent des zones à basse teneur (<3 g/t Au) par la présence de veines de quartz et de pyrite aurifère. Des zones à haute teneur associées à des essaims de veinules de quartz et de pyrite sont aussi notées dans des dykes porphyriques à plagioclase altérés en séricite et en carbonates; ces dykes se sont comportés comme des corps compétents durant le cisaillement. La déposition de l’or dans le zones à haute teneur a été contrôlée par la circulation du fluide hydrothermal au coeur de la zone de cisaillement durant la déformation des roches volcaniques et la fracturation des dykes porphyriques."

Jan 1, 2006

By A. Glover

As the demand for natural gas as a prime global energy source continues to grow, the search for new sources of the fuel spreads into geographical areas that are more remote from the marketplace. Along with this comes the need for longer and ever more efficient pipelines. This requirement for higher value in natural gas transportation is satisfied to a large extent through the application of high strength technology and innovative design approaches that support increased design and operating pressures. This paper reviews the latest accomplishments and successes in these technologies for use in gas transmission. It also explores some of the technologies which are targeted for the future to allow the industry to achieve even higher benchmarks in reliability and cost-effectiveness. The central element in the theme of high strength technology for gas pipelines is that of high strength steel. From tensile strengths of Grade 359 a few decades ago, more and more operators are now specifying Grade 550 linepipe for their large diameter projects. As well, Grade 690 steel is operating successfully in limited transmission applications and Grade 825 has recently been installed. With the introduction of the latest high strength pipe comes the need for high strength fittings. The industry&apos;s first Grade 550 fittings were recently specified and installed on a project with Grade 825 line pipe. High strength materials can only be implemented successfully if compatible design and construction processes are in place. The latest developments in strain- and reliability based design will be described as well as the corresponding advancements in welding and inspection technology.

Jan 1, 2005

By Mehmet Canbazoglu, Kaarlo Haavanlammi, Hannu Laitala

Cobalt is currently a critical metal because of the increasing number of electrical vehicles forecast for production. Copper and zinc are base metals that are used in many everyday applications, including vehicle production. Eti Bakir Co. Mazidagi Phosphate Plants in the Mazidagi district of Mardin, Turkey is a multi-product facility that produces cobalt, copper, and zinc, as well as fertilizers, from the roaster calcine. Roaster off gas is treated in a sulfuric acid plant (SAP) and the acid itself is utilized in fertilizer production. The comminution circuit, roaster, SAP, and calcine leaching process were developed by Outotec and integrated with the fertilizer production process implemented by Eti Bakir A.Ş. This paper describes the hydrometallurgical calcine leaching process used at the plant, with a focus on the oxidative pressure leaching of the cobalt, zinc, and copper-containing calcine. The cold and hot commissioning phases of the pressure leaching autoclave start-up are discussed together with experiences from the ramp-up period. The production processes of the copper cathode and cobalt and zinc-containing salts are also presented together with some of the plant’s operating parameters. INTRODUCTION The ETI Bakir A.S. fertilizer plant, Turkey, is located in Mardin Province near the border with Syria, (Figure 1). The leaching plant project was started in 2012. The purpose of the plant is to separate the valuable metals from the calcine produced by the pyrite roasters, which are used to produce a SO2 containing gas for the new sulfuric acid plant. Fertilizer production requires sulfuric acid, and for this reason a sulfuric acid plant was built; customer already had access to pyrite concentrate, which is used as the roaster feed. During the engineering phase of the roaster and acid plants it was noticed that the roasted calcine contained considerable amounts of valuable metals like cobalt, copper, and zinc. To recover these metals, a calcine leaching process was developed at the Outotec Research Center in Pori, Finland. The main process connections of the Mazidagi site are shown in Figure 2.

Jan 1, 2019

By J. R. Andrews, R. P. Young, J. M. Reyes-Montes

"Microseismic monitoring provides insight into the location and extent of rock-mass fracturing induced by cave mining, enabling interpretation of the cave profile and validation of predictive numerical models. Source location uncertainties can lead to misinterpretation of the inferred characteristics of the fracture network. One principal source of uncertainty is the velocity model used to invert the location algorithm. Large-scale 3D numerical models of modulus changes across a caved mass can represent such complexities in the location algorithms, allowing more accurate interpretation of the microseismic activity. A Northparkes mine case study applies this advanced approach to microseismic data interpretation.RÉSUMÉ Le suivi microsismique fournit des renseignements sur la localisation et l’étendue des fractures de la masse rocheuse induites par l’exploitation par blocs foudroyés; cela permet d’interpréter le profil de la chambre foudroyée et de valider les modèles prédictifs numériques. Les incertitudes quant à la localisation de la source peuvent conduire à des mésinterprétations des caractéristiques inférés du réseau de fractures. Une des principales sources d’incertitudes est le modèle de vitesse utilisé pour inverser l’algorithme de localisation. Des modèles numériques tridimensionnels à grande échelle des changements du module d’élasticité à travers une masse foudroyée peuvent représenter de telles complexités dans les algorithmes de localisation, permettant ainsi une interprétation plus juste de l’activité microsismique. Une étude de cas à la mine Northparkes applique cette approche avancée à l’interprétation des données de microsismicité."

Jan 1, 2016

By S. G. Coultis

Turner Valley is in the foothills of the Rocky mountains, at an altitude of 4,000 feet, and is 42 miles south west of Calgary. The present producing area is 8 miles long by 1 1/2 miles wide, while drilling is being carried on over an area of 10 miles by 2 miles . There are 32 wells producing, 26 wells drilling, and 17 wells shut down, making a total of 75 wells, which range in depth from 2,160 feet to 5,900 feet, varying according toa the well location on the anticline centre wells being shallower than those located on the flank. The first indication of possible production in this field was a gas seepage on the banks of Sheep river, in what is now the Royalite plant yard (Figure 1). Geologically, this seepage proved to be located on an anticline running through the valley in a southwesterly direction. The Calgary Petroleum Products Company was formed in 1912, and under the direction of Mr. A. W. Dingman, President, and associates, the first well was drilled. Production was obtained in this well. Gas was found in several horizons from 884 feet to 3,960 feet, and oil at 1,557, 2,718 and 3,839 feet. In May, 1914, oil was struck at a depth of 3,839 feet, this being a light straw-coloured oil of 60 gravity, which was blown spraying from the well accompanied by three to four million feet of gas. The latter contained some 200 grains of hydrogen sulphide per 100 cu. ft., giving it the disagreeable odour so well known in Turner Valley gas. This strike caused considerable excitement and started the famous 1914 boom, when some 400 oil companies were formed. The well referred to produced from two to five barrels of 60 gravity oil per day, and 4,000,000 cu. ft. of gas. The oil was used in the crude form in cars and trucks.

Jan 1, 1929

By Aparup Chattopadhyay, Barun K. Gorain

"Porphyry copper deposits are the most important source of copper and also gold within the orogenic belts. These deposits are characterized by low grade copper ore (0.2% to 1% copper) and host precious metals like gold, silver and platinum. A characterization tool has been developed for complex porphyry type copper-gold deposits with an aim to quantify copper and precious metal deportment. This quantification is a challenging task due to low grades and also due to the presence of both visible and invisible precious metal content in different sulphide and non-sulphide phases. Studies were initiated on various complex ore deposits and also on samples representing various processing streams such as flotation and leach products. This paper presents the development of a systematic approach to diagnostic metallurgy using state-of-the-art optical and automated mineralogy, micro-probe, dynamic SIMS and TOF-SIMS analysis for quantification of invisible and visible precious metals content in various species. The relevance of this characterization to metallurgy will also be briefly discussed in this paper.INTRODUCTIONA novel characterization tool has been developed for double refractory gold ores and complex copper-gold ores using state-of-the-art technology for quantitative gold and copper deportment study. The characterization of these ores is a challenging task due to low copper and gold grades in ores, presence of both primary and secondary copper sulphide phases and variable proportion of visible and invisible gold in different sulphides phases (pyrite, chalcopyrite, chalcocite and bornite) and iron oxide phases (magnetite, hematite and goethite). A study was initiated on various ore deposits and also on samples representing various processing streams of pilot plant batches such as flotation concentrates and tailings. This paper attempts to discuss the deportment characterization methodology through presenting results from investigations on four samples from a flotation circuit viz, Feed, Final concentrate, Cleaner Scavenger Tail and Rougher Tail samples. These four samples represent the key streams for a typical copper-gold flotation flow sheet. The key objective of this investigation was to identify and quantify visible and invisible gold along with understanding the morphology and liberation of gold associated with various sulphides, Fe- Oxides and non-sulphide gangue species. In addition, the aim of this study was also to relate this mineralogical and gold deportment information to metallurgical performance."

Jan 1, 2013

By W. B. Dingle

"IntroductionMANY PAPERS presented on developments in the Canadian Petroleum Industry •during the past few years have commenced with this general sentence: ""The past year has been a record •one for the oil industry in Canada, with new records being set in nearly all phases •of exploration and development ,activity"". This sentence applies equally well to 1951. It is not possible to outline all the details of the broken records in exploration, development, and production but general comparisons can be made. There are several significant developments that have stolen the spotlight during 1951, some of which were foreseen in 1950 and some which were not. Among the high-lights were the following:(1) The greatly •expanded activity in the search for gas, which was touched off by the new Alberta regulations covering gas leases and reservations.(2) The discovery of commercial oil production in the Williston basin of North Dakota and Manitoba, which will have far reaching effects on Canadian oil.(3) The greatly increased activity in northern Alberta, northwestern British Columbia, the southern Northwest Territories, Saskatchewan, and Manitoba.(4) The new discoveries in the general central Alberta area.(5) The granting •of a permit for an oil pipeline to the Pacific coast.(6) The arrival of Western Canadian crude in central Ontario.(7) The number of new refineries completed, commenced, or proposed.(8) The present •and proposed expansion in the petrochemical industry.Most of the remarks made on various exploration and development •activities will refer to Western Canada operations, primarily because the greatest •activity and the most significant developments have been there. Eastern Canada exploration and development operations were at a slightly higher level than in 1950."

Jan 1, 1952

By R. C. Wallace

Since the time when Canada&apos;s East and West were joined by the railway, and communication was established into the interior, settlements grew on the southern fringe of the great Precambrian area that formed the northern protaxis of the continent during its vicissitudes of growth. They clung precariously to the fringe of that ancient land, for the Precambrian is not generous to those who wish to live by the fruits of the soil, except in those limited areas where the Pleistocene ice-sheet has been profuse in its gifts of clay to cover the hard surface of the Precambrian rock. Later settlements spread westwards over the expanse of Cretacean plains that now form the wheatfields of the Canadian West; but there still remained in northern and western Ontario, in eastern and northern Manitoba, a pioneer race, to whom agriculture had attractions only in so far that it provided the wherewithal to lay siege to the riches of the Precambrian. And they had a vision beyond their time. More than they knew, they had seized the fact that for the complete rounding out of Canadian national life, a8 well as for the establishing of the necessary contributions towards the economic stability of Canada and its provinces, an industry in mining sh01.dd be well and truly built in the hinterland of the central provinces. Failing the winning of mineral from the rocks, and timber from the forests, there would remain between the East and the West an enormous barrier of unproductive country which would not only be an incubus to the agricultural people in their struggle for economic liberty, but would effectively, and for all time, remain an un-populated void across which the aspirations of East and West would be unable to unite.

Jan 1, 1924

By J. A. Finch, J. Vergouw

"Flotation selectivity becomes progressively more difficult to achieve with decreasing particle size. One of the possible problems is agglomeration, i.e. particles clustering together. One mechanism derives from the surface charge all particles develop in water. Agglomeration driven by surface charge is known as coagulation. One form is coagulation between particles of two different minerals of opposite charge. Another is coagulation between particles of the same mineral when conditions are such that the charge approaches zero.The paper describes the method of measuring charge and a new automated settling technique for measuring agglomeration. The phenomena are illustrated with galena and pyrite. Methods of assessing the importance of agglomeration in the plant environment are still to be developed.IntroductionFine particles can agglomerate (i.e. adhere to each other) under certain conditions. This is counter-productive for any physical separation process, including flotation. One cause of agglomeration derives from the surface charge that all particles develop in water. Agglomeration due to surface charge effects is referred to as coagulation. There are two forms of coagulation. If the surface charge is brought to near zero then the force of repulsion is lost and particles coagulate. This usually applies to particles of one mineral type and the technical tenn is homocoagulation. On the other hand, if two particles have opposite charge there is an attractive force. Since the particles in this case are usually different minerals this is known as heterocoagulation.Both types of coagulation can cause minerals to be misplaced. In the case of heterocoagulation this is fairly obvious. One example that may be familiar is slime coating (fines of one mineral coating larger particles of another) But even homocoagulation can be a problem an agglomerate of the same mineral particles can entrap particles of another mineral."

Jan 1, 1997

By W. T. Gotheridge

The principal sources of coal-dust underground are, of course, coal, and the working of coal. Coal-dust is most dangerous when it is in the finest state of division. This class of dust is found mostly on the roads, being blown or shaken off the loaded trams in transit, or carried in suspension by air currents. The air current passing from the working faces may also carry dust in suspension into the return airway, and the air current from the surface may carry dust from the shakerscreens into the intake airways. The mosl dangerous dust we have to contend with is, (a) that which is most finely divided, and (b) that which contains the most volatile matter, including the inflammable occluded gases, and also oxygen absorbed from the air. According to experiments, coal-dust in a fine and dry state would intensify an explosion, in air free from fire-damp carrying in excess of 3 ozs. of fine dust or 6 ozs. of coarse dust per cubic yard. The volatile matter in the dust must be between 12 and 31 per cent. in the ash-free coal, the latter percentage giving the highest flame velocity. It is vary difficult to propagate flame where coal-dust contains a large percentage of stone-dust, (say 50 per cent.). Shale-dust or other incombustible dust containing no volatile hydro-carbons or carbonaceous matter will prevent the extension of an explosion if mixed with coal-dust in proportion of say 70 per cent., and if the dust is finely divided and dry.

Jan 1, 1924

By G. Plascencia, C. López, J. González, D. Jaramillo, M. A. Barrón

Air jet and molten matte interaction within a Peirce - Smith converter is analyzed during the first stages of blowing using Computational Fluid Dynamics (CFD), by means of the Large Eddy Simulation and Reynolds Stress turbulence models. Jet velocities ranging from 5 to 150 mis, which involve the bubbling and open jet regimes, were considered in 2 and in 3-D numerical simulations. As a result of the computer simulations, it was found that low velocities results in gas bubbling in the molten copper, whereas higher gas velocities results in well defined plumes. The consequence of such different behaviours results in an increment in the rate of refractory wear or in copper splashing respectively. The analysis of the results may lead to improve the design of the tuyeres currently used in copper converting. Bottom blowing of air is also explored in this work. Numerical results show a strong non-linear parabolic behaviour of the jet velocity on the average velocity of copper; which means that beyond certain jet velocity, the copper de-accelerates thus reducing its velocity. This may be due to the open nature of the jet, which prevents the momentum transfer from the injected gas to the molten copper.

Jan 1, 2007

By C. Desmeules

"Carbon addition in the oxide pelletizing process is a big concern at the Sidbec-Normines pelletizing plant since 1976.Laboratory pot-grate testing carried out before the initial start-up of the Port-Cartier plant indicated that the nominal pelletizing grate capacity could be increased by fifteen per cent with a suitable carbon addition. Also an improved induration cycle offered the possibility of a significant energy reduction within the process with no adverse effect on pellet quality. A one-month plant scale program duplicated the lab test results and confirmed the anticipated cost saving by using these techniques. Since March 1980, Sidbec-Normines used coke addition as a current operation.This paper reviews briefly earlier laboratory and in-plant test work carried out to investigate the effects of adding carbon materials to the Fire Lake hematite concentrate, and presents operation techniques and plant results of carbon addition in the Port -Cattier pellet plant.IntroductionThe Sidbec-Normines pelletizing plant at Port-Cartier, Quebec, is designed to produce six million ton s per year of oxide pellet s. It is a Dravo-built two-line plant; one line to produce three million s tons per year of blast furnace grade pellets averaging 5.5 per cent silica, and another line of three million ton s to produce direct reduction grade pellets of about 2.0 percent silica.The laboratory pot-grate test program was conducted in 1977 at the British Steel Corporation Research Laboratories in England, with the assistance of J .E. Appleby, consultant to British Steel Corporation (overseas services) Limited.The purpose of that test program was to determine the optimum energy saving cycle and to study the physical and metallurgical effects on blast furnace and direct reduction pellets."

Jan 1, 1983

By V. I. Lakshmanan

Recycling helps to save energy and is good for the environment. It is also important for preserving the limited natural resources. In addition, recycling creates economic benefits and frees up space at the landfill sites. Process Research Ortech Inc. (PRO) has conducted extensive testwork in the area of waste processing and recycling. A process was developed for the recovery of Zinc from galvanized steel by alkaline leaching followed by solvent extraction and electrowinning. Extensive testwork has been conducted at PRO to obtain a useful by-product from rice husk. Rice husk was combusted in a gas/solid reactor to obtain an environmentally acceptable amorphous silica ash suitable for use in high strength concrete. In another development, vanadium was recovered from fly ash by separating carbon first, followed by alkaline pressure leaching, solvent extraction and precipitation. PRO has also developed an environment friendly process for treatment of industrial wastewater for its reuse to obtain zero or minimal effluent discharge. In this paper, four case studies related to recycling of zinc scrap, controlled combustion of rice husk, processing of fly ash, and reuse of waste water will be discussed.

Jan 1, 2011

By B. W. Clyburn

"Coals from the Corporation&apos;s Lingan and No. 26 mines are classified as high-volatile A bituminous, with a very low inherent ash and containing a/l essential properties to provide metallurgical coal, with the exception of a high sulphur content. Only through proper cleaning at low specific gravity can the pyritic sulphur fraction of the coal be liberated to an extent where final sulphur meets coking standards. This first section of the paper deals with the operation of a Dutch State Mines heavy-media cyclone circuit to achieve an actual separation in the region of 1.30 specific gravity. A discussion of the parameter of control which must be applied along with an appraisal of the results obtained is included in the paper.IntroductionVery high fluidity and unusually low ash are the outstanding characteristics of coal from Devco&apos;s mines in the Harbour seam of the Sydney coal field.However, sulphur content, mainly pyritic, ranges from 1 to 2.5070. To obtain the low and consistent sulphur level required in metallurgical coking coals, preparation at low specific gravity is required .Metallurgical coke is used as the fuel in an iron blast furnace. Its sulphur content largely determines the quantity of slag required to remove it and therefore influences furnace productivity and unit costs.Typical data on the various coal properties of importance in the production of coke are included in Table I. Necessity of Low-Gravity SeparationThe design of any coal preparation plant requires the study of washability properties of the coal to be treated to determine the quantity and quality of coal produced at a given specific gravity along with the difficulty in accomplishing that separation.Their low ash content allows the important washability aspects of Harbour seam coals to be represented by sulphur! specific gravity curves (Fig. I). This particular example indicates that a yield of 54.5% is attained, at a sulphur content of 1.20%, for a perfect separating device operating with a 1.29 S.G. cut point.Material rejected from this separation still contains usable coal, which is recovered as middlings by separating at a higher gravity."

Jan 1, 1980