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By W. Beres, R. E. Miller, B. Shiari, L. R. Zhao

A dynamic multiscale (MD/FE) method has been used to study dislocation generation and plastic deformation during a nanoindentation process which is physically associated with the generation of heat within the specimen and as a consequence with a temperature rise. Two different techniques are applied to study the temperature effect on the nanoindention process. In the first technique, a global Nose-Hoover thermostat is applied to the entire atomistic region to keep temperature constant during simulation (finite temperature approach). In the second method, the thermostat is applied only on a damping region along the MD/FE interface. Both techniques are able to effectively and efficiently absorb high frequency reflected waves from atomistic/continuum interface. The temperature profile of the atomistic region beneath the indenter is reported and discussed at four different initial substrate temperatures for both techniques. The loaddisplacement (load/unload) curves for different temperature-controlling techniques are compared and discussed. The nucleation and propagation of dislocations in the atomistic region are investigated for both techniques. Correlations between the observed features in the load-displacement curves with the motion and pile-up of dislocations are reported as a function of temperature.

Jan 1, 2006

By D. Nie, M. Ren, T. Mo

This paper studied the phenomenon of room temperature creep deformation at crack tip and its effect on fatigue crack growth rate of a X-70 pipeline steel using compact-tension (CT) specimen on a MTS 810 testing machine. Time-dependent deformation at the crack tip under constant load was observed in this steel at room temperature and the amount of deformation produced was seen to depend on loading rate and the magnitude of stress intensity factor. It is found that there exists a critical stress intensity factor below which the deformation decreases with time when the applied load remains constant. It is also found that the occurrence of room temperature creep obviously affects the subsequent fatigue crack growth rate. The observed behavior was explained based on dislocation theory.

Jan 1, 2005

By David Morrison

Our present longwall problems in Cape Breton can be grouped under five main classifications. These are: (1) Roof control on the face and on the main roadways leading thereto. (2) Transportation of coal along face and levels. (3) Mechanical loading at the face. (4) Safe method of conducting and applying power at the working faces. (5) Dust nuisance. The usual layout for longwall operation in Cape Breton is to have three, and sometimes four, faces in line with each other, the length of face being from 400 feet to 500 feet (see Figure 1), and producing between 425 and 500 tons per face. Each wall is serviced by a well constructed roadway for transportation of coal, men, and materials, and is operated as an independent unit. Each wall works under a regular cycle of operations: first, cutting and boring; second, drawing hardwood chocks, building midwalls, and shifting panlines; and third, loading. The present method of roof control and operation of longwall faces has developed through trial and error since the commencement of longwall miring in Cape Breton. The basic method of roof control in all longwalls in Cape Breton is: rigid support of the roof in the immediate vicinity of the working faces by hardwood blocks, as shown in Figure 2, accompanied by a cushion support furnished by continuous midwalls, 12 feet wide, constructed of stone obtained from the waste and spaced at 50-foot centres. These midwalls are kept forward to within 4 feet to 10 feet of the working face and allow a gradual subsidence of overhead strata, thus preventing any sudden break at the working face.

Jan 1, 1947

In the leaching and recovery of gold from copper containing gold ores using cyanidation, some copper minerals also dissolve which can have a detrimental effect on the process efficiency and economics. There are also environmental concerns with current operations discharging cyanide and copper cyanide species into tailings dams, and strict regulations prohibit this for greenfield plants. Cyanide destruction however is not an economic option for new plants treating copper-gold ores. This paper evaluates a potential recovery process to overcome the copper cyanide problem. Despite gold dissolution occurring in copper cyanide solutions having no free cyanide, gold recovery from ores is lower compared to free cyanide. Thus, cyanide addition has to be optimised to maximise the gold recovery whilst endeavouring to eliminate free cyanide at the completion of leaching (CN:Cu less than 3:1). Subsequently, copper cyanide can be recovered using activated carbon. The loaded copper cyanide is easily recovered from the carbon with a cyanide soak and distilled water wash such that the eluted CN :Cu ratio is less than 4:1. The copper could be recovered efficiently by electrowinning, by decreasing the pH of the eluant to 5. The remaining cyanide solution, after electrowinning, is then neutralised to form NaCN and recycled.

Jan 1, 2005

For the last few years, a new and innovative technique has been successfully used to determine refractory and castable thickness in various metallurgical vessels. The acousto ultrasonic-echo (AU-E) technique uses stress waves to detect metal penetration and delaminations within refractory linings. In addition, it is capable of measuring the thickness of refractory layers and build-up material. The inspection and measurements can be carried out while the furnace is in full operation. The present paper discusses the principles of the AU-E technique, and its advantages and limitations. A number of case studies are presented to demonstrate various capabilities of this new Non-Destructive Testing (NDT) technique.

Jan 1, 2005

By Claudia Gasparrini

"Silver occurs in about 200 minerals in variable amount s. Silver ores usually have 5 or 6 and in some instances as many as 10 species of silver minerals. All these minerals may have different flotation and leaching properties and should be correctly identified for successful recoveries. Grain size and host minerals which are critical in gold recovery, are not always as important for silver minerals.IntroductionMineralogical factors affecting the metallurgy of silver are , as for other metals: (i) the silver-bearing mineral s ; (ii) their grain size, and when dealing with very fine sizes; (iii) their host minerals; and (iv) the association they form with the silver-bearing minerals. Of these, the silver-bearing minerals are more often the cause of problems during recovery as opposed to gold whose metallurgy is generally more affected by grain size and host minerals. The problems derive mainly from the complexity of the silver mineralogy: over 200 minerals exist bearing the element in major, minor and variable amounts.As a member of group I-B of the periodic table, silver forms extensive so lid solutions with the other two elements in the same group , copper and gold. It combines with sulphur, tellurium and selenium in covalent bonds and with chlorine, bromine and iodine in ionic bonds. Where the fluid composition, temperature and pressure during crystallization allow it, silver also combines with arsenic, antimony, lead, bismuth, tin, mercury, indium, thallium, and germanium in many instances as a minor element in sulphide , sulphosalt and native element minerals. Cations which silver replaces to a lesser extent than copper and gold are iron, manganese, zinc and probably nickel and cobalt."

Jan 1, 1984

By S. Esmaeili

The yield strength model developed by Esmaeili, Lloyd and Poole [1] has been adapted to model isothermal aging in Cu-containing AA6xxx alloys, with (a) a moderate and (b) a very low Cu content in the solution-treated, as-quenched, condition, Isothermal calorimetry has been used to analyze the kinetics of precipitation in these alloys, While the kinetic parameters for the low Cu alloy has been derived from the present experiments, the previously determined kinetic parameters for the high Cu alloy AA6111 has been used to model the precipitation kinetics in the moderate Cu alloy. The age hardening responses of both alloys have been well predicted by the model.

Jan 1, 2005

By L. O. Cooper

IN THE operation of most mines, hoisting ropes, made of steel, play a very important part in the conveying of men and material between surface and the underground workings. It is obvious that, in order to maintain a maximum degree of safety, certain restrictions must be placed on the loads that may be carried by hoisting ropes, as well as on other factors that may affect the life of the rope. It is the purpose of this paper to suggest ?a new method of defining the necessary restrictions. The three main stresses in a hoisting rope are the static stress, bending stress, and dynamic stress. Crushing stresses, which are also present, are largely indeterminate and may best be allowed for by proper grooving of drum and sheaves, by adequate inspection of cross-over points, and by limiting the number of layers on the drum. They will, therefore, not be considered in this analysis. In the ?recent Ontario regulations, the limiting conditions for the main stresses are specified separately. The static stress is limited by setting a minimum static safety factor of 5.0 The dynamic stresses are allowed for by specifying a minimum capacity factor of 8.5, which has the effect of increasing the safety factor required at smaller depths in a uniform manner. The bending stresses are limited by calling for a drum-dia./rope-dia. ratio of at least 60 for ropes up to 1 inch in diameter and 80 for ropes greater than 1 inch in diameter. One disadvantage of this method is that the controls are too rigid and do not allow the operator sufficient freedom of action within safe limits.

Jan 1, 1951

By L. Freitag

"The Dollard oil field in southwestern Saskatchewan is a stratigraphic trap of irregular shaped perimeter. The reservoir is a low-angle monoclinal structure with a dip of approximately 100 feet in 5 miles from west to east across the long axis of the reservoir. Production of. 23° API gravity crude is obtained from a Jurassic sand referred to as the J-2-A, at an approximate depth of 4,500 feet. Reservoir studies and fluid analyses revealed that the crude is highly undersaturated, having a solution GOR of approximately 130 cubic feet of gas per barrel, that the reservoir has no definable water table, and that it appears to be of a closed-boundary type. Oil production was marked by a rapid pressure decline and it was soon evident that the greatest ultimate recovery would be best obtained if the natural driving energy of the reservoir were augmented by some artificial energy source. In support of a pressure maintenance programme, studies were conducted on flood-pot recoveries of large-diameter cores, and a potentiometric model study of the field was made. These studies indicated that a successful water flood would be obtained. The Dollard field was unitized in 1955 and pressure maintenance started in March 1956."

Jan 1, 1959

By Tim Robinson, Michael S. Moats, William G. Davenport, Andreas Filzwieser, Andreas Siegmund, Shijie Wang

This survey continues the long tradition of providing a snapshot of operating data from industrial electrorefineries. It is a supplement to previous surveys that were performed in 1987, 1991, 1995, 1999, 2001, 2003, 2007, 2010, 2013 and 2016. Analyses of current data and historical trends are presented. Examples of innovations to reduce costs, improve productivity, and improve quality are provided. In general, refineries continue to increase productivity while treating anodes with more impurities. INTRODUCTION This manuscript analyzes global survey data provided by operating copper electrorefineries. This paper continues a series of surveys of copper refining tankhouses that started in 1987 (Schloen, 1987, 1991; Schloen & Davemport, 1995; Davenport et al., 1999; Robinson et al., 2003; Moats et al., 2007, 2013, 2016). In this installment, data collected from 2015 and 2018 will be presented and analyzed. The 2015 survey data were presented at Copper 2016 in Kobe, Japan. This survey will continue the analysis of previous data to illustrate long term trends in copper electrorefining, which were originally presented at the Davenport Symposium in October, 2014 (Moats, Robinson, & Wang, 2014). Refineries who supplied surveys are listed in Table 1. Cathode production data from 2015 and 2017/18 (from surveys presented in 2016 and 2019) are provided to indicate which plants provided surveys and when. This manuscript presents operating data for ~6.5 million tonnes of copper production, which represents 30–35% of the world’s copper electrorefining production. The detailed survey results are available upon request from the corresponding author.

Jan 1, 2019

By Grant Arnold

Le Camp Minier de Matagami est situé dans la ceinture volcano-sédimentaire Harricana- Turgeon appartenant à la Province du Supérieur, sous-province de l?Abitibi, au Québec. Les gisements de métaux de base polymétalliques sont retrouvés exclusivement dans les deux domaines lithotectoniques comprenant l?association basalte-rhyolite (Matagami-Brouillan et Joutel-Raymond). Tous ces dépôts, à l?exception de ceux de Selbaie, sont de type exhalatif et représentent des dépôts volcanogènes à Zn-Cu, typiques de l?Archéen. Le complexe volcanique de Matagami est constitué principalement de deux phases de volcanisme tholéïtique. Les dacites et les rhyolites du Groupe de Watson, représentent la phase la plus précoce et celles-cis sont recouvertes par la seconde phase qui est constituée majoritairement de roches intermédiares à mafiques intercalées d?horizons felsiques, formant le Groupe de Wabassee. Un sédiment chimique sulfuré, la Tuffite Clef, marque le contact et l?hiatus entre ces deux groupes. Cette tuffite est reconnue à la grandeur du flanc sud du camp minier et représente l?horizon favorable à explorer puisque sa déposition a correwspond à une période d?intense activité hydrothermale. Le complexe volcanique de Matagami est limité au nord et au sud par des bandes sédimentaires orientées est-ouest, connues respectivement sous les noms de Groupe de Matagami et Groupe de Taïbi. Le Complexe intrusif de la Rivière Bell, qui occupe la base du Groupe de Watson, est un complexe lité consistant en une séquence stratifiée gabbroïque avec localement des niveaux stratiformes à concentrations d?oxydes magmatiques, la bordure de ce complexe est marquée par la présence d?un horizon granophyrique. Cette intrusion synvolcanique prétectonique, représente probablement la source de chaleur étant à l?origine de l?activité hydrothermale observée dans les roches volcaniques sus-jacentes. Suite à un levé aéroporté, le camp minier de Matagami a vu le jour en 1956 lors de la découverte du dépôt de Mattagami Lake, un gisement volcanogène de 25.6 millions de tonnes. Depuis ce temps, un total de neuf gisements ont été exploités et un dixième, Bell Allard, est présentement en production. En date du 31 décembre 1999, la production historique du camp s?élevait à plus de 41 millions de tonnes. Cette présentation mettra l?accent sur la géologie des récentes découvertes dans le prolifique camp minier de Matagami. Les ressources publiées pour le dépôt Persévérance sont de 947,000 tonnes titrant 19.12% Zn, 1.37% Cu, 32 g/t Ag et 0.40 g/t Au. Deux autres découvertes, Équinoxe et Persévérance Ouest contibueront à la ressource globale. Les trois dépôts sont situés au niveau de la Tuffite Clef même si les roches sus-jacentes ne sont pas celles typiquement observées dans les autres dépôts du flanc sud. Ces découvertes sont le résultat d?un programme d?exploration ciblé et soutenu, démontrant ainsi la possibilité de découvrir de nouvelles ressources même dans les camps miniers comme Matagami qui ont été explorés intensivement depuis plus d?un demi-siècle.

May 1, 2001

By T. H. Adair

"IntroductionCONTINUOUS casting of ferrous and non-ferrous metals is not a new innovation. Patents describing machines for continuous casting are on file as far back as the year 1842. In the middle of the last century, Sir Henry Bessemer conceived and built a continuous casting• machine for the production of mild steel sheet.The production of billets and slabs of both non-ferrous and ferrous metals is being carried out by the continuous method on a fairly large scale on this continent and abroad. At present, the volume of production of •copper and aluminum and their alloys in billet and slab form is much greater than the continuous casting of steel products. The new installation of a continuous casting unit at Atlas Steels, Limited, is designed primarily for the casting of alloy steel billets and slabs.As an introduction to the art of continuous .casting of metals, it is interesting to examine a few of the many devices which have been developed. As previously mentioned, Sir Henry Bessemer constructed a machine for the direct casting of mild steel sheet. His discoveries and ideas of continuously casting steel formed the foundation for the work of other pioneers in this field, all of whom have contributed to the improvement of this art through the ensuing years. The machines which will be selected for examination are those of Bessemer, Poland-Lindner, Williams, Ennor, and Junghans. The last unit to be discussed will be a modification of the Junghans machine recently installed at Atlas Steels."

Jan 1, 1954

By Y. Wong

The quality and quantity of secondary deposits, which include tailings streams and tailings dams, are increasing around the globe. The tailings are already mined, available and liberated to such an extent that the recovery of a valuable product is highly economical in terms of CAPEX & OPEX. The most widely used process for the recovery of these valuable ultra-fine haematite iron particles is the Wet High Intensity Magnetic Separation technique, originally developed by Dr. Jones over 55 years ago. Many of the original machines are still working today. The aim of this paper is to demonstrate the capabilities in terms of grade and yield of using sophisticated magnetic separation modules. All results and figures are obtained from test works, design- and engineering works. Two types of tailings have been identified for processing. Firstly, tailings that have already been deposited in a Tailings Storage Facility, and secondly, live tailings streams from an existing wet iron ore beneficiation plant. In both cases, the technical and practical results are shown along with relevant flow sheets and plant layouts. Finally, this paper highlights the total predicted power- and water consumptions, capital requirements and projected operating expenses. The results show that the operating costs are significantly lower than the mining and processing operations which are required for an equivalent amount of iron ore. The recovery % of iron depends on various factors but is within the 30–50% range, at an equivalent grade to the mainstream product. Another significant benefit is that the magnetic separation process is water positive, meaning that water is released rather than added in the process. The processing of secondary deposits will therefore result in an overall reduction in operating costs, an increase in product yield from a plant, extend the mine life and offer environmental benefits by reducing the tailings footprint and water usage.

Jan 1, 2016

By W. Yang, R. Rajasingam, K. Mohanarangam

"Copper Electrowinning (EW) is a complex electrochemical process that involves the production of LME grade copper from copper rich electrolyte. The process involves the deposition of the copper ions onto the cathode from copper rich electrolyte with the production of oxygen bubbles at the anode. The process setups up a complex flow pattern within the cell as it is subjected to varying density gradients due to the deposition process along with oxygen bubble driven flow. It is a necessity to understand and quantify the flow behaviour within these cells in order to maintain the production of highest grade copper. In fact, the oxygen bubbles originating from the process is responsible for the generation of acid mist which is a designated as a carcinogen a major health hazard around EW tank houses. Hydrodynamic assessment of the process has so far been restricted to simple mass balances and some limited numerical modelling. All the models are based on assumed boundary conditions which has not so far been verified by any real-time physical measurement. This apparent gap has led to models which could not be directly used to track process changes or troubleshoot problems in EW tank houses. In order to address this gap, CSIRO has established a full size (width and height) transparent cell capable of simulating plant operating conditions (across the range currently used). With the use of sophisticated diagnostic analytical tools and measurement techniques it was possible to study all the operating variables (current density, flow rate, temperature, etc.) independently and their effect of bubble size, bubble velocity, gas hold-up as well as acid mist generation and its size. In order to address safety concerns in tank houses around acid mist early results outlining the factors contributing to its generation as well as the effect of various barriers to mitigate acid mist is outlined below.INTRODUCTIONA significant part of today’s copper production is through hydrometallurgical route which predominantly involves leaching, Solvent eXtraction (SX) followed by ElectroWinning (EW). Producing copper using this approach have shown to be environmentally friendly (Dresher, 2001) compared to the traditional smelting process. EW is the final step in the production of LME grade copper using the hydrometallurgy route. The electro-chemical process involves the use of a lead anode (Pb-Sn-Ca) and a stainless steel cathode to produce copper sheets using the copper rich electrolyte from the SX process and with the applications of direct current to the electrodes. This electro-chemical reaction results in the deposition of copper ions on the cathode with oxygen released from the anode as a by-product. Hydrodynamically, the oxygen bubbles create a bubble driven flow within the EW tanks with the surrounding electrolyte. A direct result of this could be seen from the quality of the copper deposited on the cathode. Most of the copper plates produced from the traditional tank houses have a rough texture at its bottom one-third while the top two-thirds have a smooth finish with a finer grain structure."

Jan 1, 2016

By J. E. Danoczi

Shore Gold Inc. (Shore) is presently designing a diamond processing plant for the Star and the Orion South kimberlite deposits in the Fort à la Corne area kimberlite field in central Saskatchewan. The first step in the plant is diamond liberation and occurs in the comminution section. Diamond liberation is the process of breaking up the kimberlite rock, as ?gently? as possible since essential to the diamond liberation process is the minimization of diamond damage, particularly for the larger, high value diamonds. The Southern African diamond mines traditionally use Jaw and Gyratory crushers as their primary comminution method. However, these diamond mines generally process the harder, competent kimberlite that is located in the diatreme zone as well as the root zone of the volcanic pipe. Softer kimberlite is typically located in and around the crater area of a volcanic pipe and it is this source of kimberlite that makes up the majority of kimberlite for both the Star and Orion South deposits. These softer kimberlites can be readily broken up using abrasion and attrition imparted by AG mills, this being the preferred method of comminution for minimizing diamond damage.

Nov 1, 2011

By Andrew Popko

Introducing EnCana ?? A leading North American Oil and Gas company ?? Focused on natural gas and oil sands development in 12 key resource play areas across North America ?? In 2007, over 4300 wells drilled, producing about Enterprise value of approximately $50 billion ?? Invest between $5.8 Billion in 2007 ?? Over 7500 employees ?? Headquarters ? Calgary, AB

May 1, 2008

By G. Bimpilas, G. N. Anastassakis

"Today, one of the most intense problems in mineral processing systems is referred to the treatment of fine (–100 µm), and even smaller size, particles. Fine mineral particles possess specific properties (small mass, high specific surface area, and high surface energy per unit area) that render their separation inefficient with conventional methods (physical, physicochemical) and equipment. As a result, it is not feasible to obtain a concentrate both of high grade and recovery in mineral value and a considerable amount of mineral fine particles is lost to the tailings. As evidence, we could cite numerous examples from industrial practice with considerable loss of mineral values to the tailings because of the fine particles size, e.g. phosphate, tungsten, tin, etc.The objective of the current paper is to investigate the possibility to separate magnetic gangue minerals and rocks (serpentine, ilmenite, and olivine) from magnesite by co-agglomerating all the gangue components and subsequent magnetic separation of the agglomerates.To meet the target, hydrophobic agglomeration tests were initially carried out on single minerals to define the favorable conditions for selective hydrophobic co-agglomeration of the gangue minerals. In this respect, the effect of the following factors was examined: pH, collector dose, conditioning time, and settling time of the agglomerates. Among the combinations examined, the most favorable proved that with amine in the basic pH region. The use of non-polar oil proved beneficial. The preliminary results were confirmed by tests on mineral mixtures. The application of magnetic separation resulted in the removal of gangue minerals and the recovery of magnesite concentrates of commercial grade (magnesite content 95% approximately) and high yield.The current paper contributes to the development of mineral processing, since it successfully copes with a very important problem of mineral processing, such as the efficient separation of fine particles."

Jan 1, 2016

By Marcel M. Djivre

The paper will outline historically the different materials used for pouring sockets and illustrate the current trend due to inherent advantages. A section will be devoted to engineering stress analysis showing the criteria necessary for the wires not to slip inside the poured socket material. The Ontario Mining Regulations pertaining to poured sockets will be reviewed with emphasis on the acceptable type of sockets depending on usage. In addition the paper will review the proper socket preparation techniques and explain the destructive testing conducted at the Materials Testing Lab essential for the certification requirements. In conclusion the paper will show the importance of the Certification Program for the safety of Miners working in Ontario, Canada and the World. The paper is also intended to inform the Mine Operators and Consultants that to-date the .Wirelock. sockets have been used safely for hoist ropes of locked coil and non-rotating construction and for the termination of balance ropes, and that further research is required on the construction of a socket approved for rotating type mine hoist ropes.

May 1, 2003

By A. H. Lang

"The Cordilleran region of western Canada includes most of British Columbia and the Yukon and pares of Alberta and the Northwest Territories. The western part of this region was for about 50 years the principal mineral producing area of the Dominion. It lost this distinction in 1907 when production from the mines of the Canadian Shield took the lead, but it continues to provide about 15 percent of the total Canadian production. In 1945 the total mineral production of British Columbia and the Yukon was valued at $65,302,900, of which about 80 percent was derived from metals.This paper is intended to serve as an introduction co the more derailed Cordilleran papers. Part I includes a brief synopsis of the complex geology and diverse types of mineralization in the region and Parr II collates the main structural principles exemplified in the derailed papers, and draws some conclusions regarding the application of this information to prospecting."

Jan 1, 1954

By J. C. Kurnia

Presence of fine dust in air causes serious health hazard for mine operators resulting in such serious problems as coal workers? pneumoconiosis and silicosis. Major sources of dust appear of course along the mining face where the minerals are extracted. Proper control and management are required to ensure safe working environment in the mine. Presented here is the use of a computational fluid dynamic (CFD) approach to investigate the flow and dust behaviour in mining tunnels. The objective of this study is to propose and examine various strategies to mitigate dust dispersion from the mining face and reduce dust concentration to a safe level for the operator. In a companion study, the authors investigated various methods for mitigating dust dispersion from the mining face to ensure safe dust concentration levels in the mine tunnel. Among the examined methods, implementation of brattice to direct the flow from the main airway to the mining face is the most effective method to disperse dust particles away from the mining face. The installation of brattice, however, will limit the movement of mine operators and vehicles in the tunnel. Hence, application of a hybrid brattice which is a combination of a physical brattice along with suitable directed and located air curtains is proposed and examined. Based on the CFD simulation results, over a range of parameters of interest, it was found that the physical brattice blocks the ventilation air and directs it to the mine face while an air curtain located along the brattice outlet offers flexibility in keeping the dust away from the operator allowing more freedom for the operator and the equipment. Results of the modelling over a range of parameters of interest are presented and discussed with the goal of managing dust concentrations within safe limits for the operator.

Aug 1, 2013