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By R. Ghomashchi

Wear, fatigue and corrosion are the most widely encountered modes of failure in materials used in engineering applications, including aero-gas turbines. Although wear is distinctly classified as adhesive, abrasive, erosive, fretting and so on, there are usually more than one wear mechanism involved in the failure of components in service because there are many systems and materials variables active in materials wear that makes it more difficult to study. This is further complicated by the discrepancies between the results of laboratory tests and field data. The present investigation was set up to examine the wear characteristics of M50 and T1 high-speed steels at both room and elevated temperatures to draw a thorough understanding of the wear behavior of this class of high-speed steels. This article focuses on the mechanical and microstructural characterization of wear for T1 and M50 high-speed steels using a pin-on-disk wear machine.

Jan 1, 2005

By Andrea Lisjak

The mechanical behaviour of Opalinus Clay, an indurated over-consolidated argillaceous rock, is heavily influenced by the presence of preferably oriented bedding planes. The objective of this study is to illustrate a new modeling approach aimed at capturing the bedding-induced anisotropy of Opalinus Clay as observed in the laboratory and in situ. The combined finite-discrete element method (FEM/DEM) is employed as the main simulation tool. FEM/DEM is a numerical method that models material damage processes by explicitly considering fracture nucleation and propagation. A transversely isotropic elastic constitutive law is used to account for different elastic property values in the direction parallel and perpendicular to the layering, while strength anisotropy is captured using a directional cohesive fracture model. Quantitative calibration and validation of the model is based on laboratory results of indirect tensile tests and uniaxial compression tests. Emergent strength and deformation properties, together with the simulated damage mechanisms, are shown to be in good agreement with experimental observations. Preliminary results relative to the analysis of a circular tunnel show that the approach is able to reproduce the main Excavation Damaged Zone (EDZ) formation mechanisms as observed in the field.

Jun 1, 2012

By Samuel Nunoo

Gibraltar Mine is an open pit copper-molybdenum mine in central British Columbia. The stability and potential failure modes of pit walls in the Granite Pit are controlled by the orientations of joints and faults. The structural geology also has an impact on as-mined bench geometries. Geotechnical mapping and surveying were conducted using stereo photographs and photogrammetry software. Detailed digital terrain models were constructed to determine the pit wall geometry and the locations and orientations of larger structural features. The pit wall geometry is compared to conventional survey results and the mapped structures are compared to results from a nearby geotechnical borehole.

Aug 1, 2013

"HPGRs operate in a wide array of applications in mining and minerals. These range from relatively coarse crushing of copper and gold ores at one end of the spectrum to the processing of fine iron ore pellet feed and fine industrial mineral products at the other. Traditionally these circuits involve the treatment of relatively moist materials in pre-grinding circuits; using single stage HPGRs in open circuit or as a closed circuit operation with screening or partial product recycle. More recently, HPGR is increasingly deployed in dry grinding in combination with air classification. The high throughput demonstrated by larger HPGRs has stretched the application towards coarser size reduction duties for a number of new projects. At the same time, the basic principle of inter-particle crushing for generating a product with a high fines proportion gives ground to investigate applying the technology further towards finished product duties. The advantages that HPGR brings are clear. Multi Stage grinding enables energy efficient size reduction across more of the comminution circuit. Primary HPGR serves for a coarse grinding duty, whereas a secondary HPGR is geared towards generating a fine product for downstream processing or even a finished product. This publication summarizes some of the features of staged HPGR circuits and discusses some examples of operating and projected applications.INTRODUCTION In most HPGR applications, the grinding units are used as a single process stage, either in open circuit, such as for pebble crushing [Rose 2002, Westermeyer 2000, Van der Meer 2015] or in closed circuit with classification [Van der Meer 2009, 2012] or product recycling [Van der Meer 2010]. Where a higher plant capacity is required, the HPGRs are commonly installed in multiple lines in a parallel arrangement [Parker 2005, Koski 201, Vanderbeek 2006]. HPGRs can take a wide range of feed size distributions, and grind this down to a product with a high fines content. In general view, there is a limit on the size reduction range that even an HPGR can provide. Grinding down from a very coarse ore (e.g. 70-100 mm) to a very fine product (e.g. 100 microns range) is stretching the ability of a single stage HPGR circuit. Fine grinding generally requires a classification stage that returns the classifier oversize to the head of the HPGR circuit. From one point of view, it can be demonstrated that when recycling a large proportion of fines and middlings back to the HPGR feed results in an effective feed with an overrepresentation of middlings and fines, which will eventually reduce the grinding efficiency and consequently result in an increased recirculation mass flow [Van der Meer 2014]. From another point of view the large recycling mass puts a strain or even a limit on the capacity of present-day conveyor capacity."

Jan 1, 2018

By Jeffrey D. Eisenman

FRP is a proven material for the solvent extraction processes of copper production. There is a history of successful applications of FRP piping and equipment in hydrometallurgical processing. The performance of FRP equipment has not always been consistent, but at no fault of the material. Its non-metal attributes and behavior vary from those of more typical materials of construction, such as steel and alloys. FRP is a mainstay material in many areas of solvent extraction and electrowinning and yet not well understood by all. We will discuss the critical concerns, which are key to reliable performance of FRP systems. This paper will include discussion of key elements, which are fundamental to reliable FRP piping design and considered best practices. Essential design and construction considerations to maximize reliable service life of FRP equipment, such as thickeners and process vessels, used in copper extraction and processing, will be discussed. Additionally, we will expose potential pitfalls and share lessons learned from previous copper processing plant projects, which can aid and impact other copper processing projects to ensure best system performance and reliability. INTRODUCTION The corrosion resistant attributes of fiberglass reinforced plastics (FRP) make it an attractive and cost effective material of construction in corrosive service applications that are found in copper processing. FRP is used all over the processing plant in seawater, brine and sulfuric acid services where the corrosive nature of these services would challenge most ferrous materials and coatings. FRP is a fully customizable material to meet the specific needs of each service and process. FRP piping and equipment can be found throughout the hydrometallurgical process, in the acid plant, desalination, leaching processes, solvent extraction and electrowinning to name a few. Beyond its superior corrosion resistant characteristics, FRP can be made abrasion resistant by introducing particulate additives into the resin, such as silicon carbide and alumina oxide. Because many of these services have combustible organic elements in the flow streams with accompanying safety concerns, the linings can be made conductive with carbon fibers to dissipate static charges that might collect on the surface of the equipment otherwise. Further, FRP can be made flame retardant as well, where flammability may be of concern.

Jan 1, 2019

By R. U. Seneviratne, B. K. Ahlgren

In this paper we follow various technological discoveries and developments in the purification of minerals and metals in the mining industry by ion exchange. For approximately 100 years, ion exchange has been a known and variously applied purification and separation technology used by scientists and producers. It would seem obvious that the producer’s objectives have always been to achieve the highest quality products and the lowest operation costs, but also with the least amount of technological complexity. As a strategy to reach these goals, much effort has been expended in the quest to improve continuous ion exchange (CIX) systems by reducing utility needs and resin degradation or loss while at the same time improving productivity and reliability. Recent developments from a number of companies have pushed equipment boundaries, resulting in a variety of unique commercial equipment designs each with a varying degree of success. The challenge set forth for all new designs has been a truly continuous process with no sacrifice in the afore mentioned benefits. One very recent equipment design based on system symmetry appears to meet many of these objectives with greater flexibility and less complexity resulting in better economics for the producer.

Jan 1, 2014

By A. J. Russell

"This paper investigates why it is critical for a mine to accurately determine thermal rock properties and virgin rock temperatures. Theoretical simulations of deep mining production zones have demonstrated that thermal conductivity (k), virgin rock temperatures and specific heat (cp) significantly impact rock heat predictions which can be the dominant component of a mine’s heat load. Natural variability in these factors showed that realistic errors can have a significant effect on mine heat loads. This can ultimately affect miner safety and introduces risk to the viability and sustainability of a project. INTRODUCTION Accurate heat load determinations are critical to ensure that underground working conditions are maintained within legislated and mine specific parameters to safeguard the safety and productivity of employees. Underpredicting mine heat loads will result in hot underground conditions, which risk the health and safety of employees, reduce the productivity of employees or stop production if legislated temperatures in working areas are exceeded. Overestimating mine heat loads will result in increased capital and operating costs reducing the viability of the project. Over- or under- predicting the heat load for a project will increase the project risk. Heat sources in a mine can broadly be broken into two categories. These two categories are defined by Hemp and Rawlins (2014) as natural and artificial heat sources. Those sources which depend on the size, location and depth of the mining areas are defined as natural heat sources, whereas those heat sources which are a result of the actual mining activities are defined as artificial heat sources. Autocompression, or the conversion of potential energy, to enthalpy is an important consideration when determining the air temperature in the mine and its interaction with natural and artificial heat sources. It is documented by Jones (1985) and Hemp and Rawlins (2014), that the heat flow from rock in deep mines can dominate other heat sources; information from BBE’s archives show that this is between 40% and 60% of the total heat load. They also point out the importance of accurately measuring both the thermal rock properties and virgin rock temperatures (VRTs) for determining and planning the ventilation and refrigeration requirements for a mine. Both of these texts cite multiple methods for calculating the heat-flux and ultimately the heat load for the different working areas in a mine. All of these methods demonstrate that the heat flux and heat load will increase proportionally with increased thermal conductivity (k), specific heat (cp) of the rock or mineral, and VRT depending the area of the mine or mining method."

Jan 1, 2019

By H. Clare Horwood

"In the Little Long Lac-Sturgeon River area of Thunder Bay district, Ontario, most of the known ore deposits occur in fractures, shear zones, and zones of brecciation, in folded sedimentary rocks . In two or three instances, however, deposits occur in Keewatin greenstones and in later granitic rocks of probable Algoman age.The principal regional features in the area are the long narrow bands of Keewatin volcanic rocks and Timiskaming sedimentary formations that extend east from lake Nipigon to Long Lac, a distance of about 65 miles. The belts continue to the east for many miles beyond Long Lac and probably for some distance to the west under the waters of lake Nipigon. They are intruded in places, particularly in the north, by large masses of diorite, granodiorite, and granite. Small intrusive masses of diorite and porphyry also occur in many localities throughout the area.The Little Long Lac-Sturgeon River mining area is the youngest camp in Ontario and has been in production only since 1934.The district is readily accessible from the branch line of the Canadian National railway between Longlac station on the main line and Port Arthur, and from the Trans-Canada highway No. 17. Both these means of communication traverse the area in a general east-west direction parallel with the principal structural trend of the rocks of the region.In the Little Long Lac section discoveries were made by W. W. Smith in 1931 (Hard Rock property) , by T. A. Johnson in 1932 ( Bankfield property) , by T. A. Johnson and T. Oklend in 1932 (Little Long Lac property) , by F. MacLeod and A. Cockshutt in 1933 (MacLeod-Cockshutt property) , and by George and Frank Papineau in 1935 (Hutchison Lake property).In the Sturgeon River section discoveries were made by Powers and Silam in 1925 (Northern Empire property), T. A. Johnson in 1931 (Dik-Dik property) , and by Russell and James Cryderman in 1935 and 1936 (Sand River and Leitch properties)."

Jan 1, 1954

By K. Torigoe, S. Owad, C. Tokoro, Y Tsunazawa

The mechanism of an abrasion process to recover metal values by removing components from printed circuit boards (PCBs) is modeled using a discrete element method (DEM) simulation. To simulate the abrasion process, a model PCB geometry was constructed consisting of bonded particulates. The simulation allowed connections between particles to be broken if the bonding force calculated from DEM exceeded a threshold level. Simulation results were compared with experimental comminution data using an agitation mill with test PCBs on which nine capacitors were surface solder-mounted. Simulation results obtained from the DEM with the anchoring model corresponded to experimental observations.

Jan 1, 2011

By S. I. Saif

The Key Anacon deposit lies about 6 miles northeast of the Brunswick NO.6 mine of Brunswick Mining and Smelting Corporation. Geological mapping, especially in the well-exposed Nepisiguit River section, geophysical data, and information from extensive underground and some surface drilling show that the rocks at Key Anacon are similar in many aspects of stratigraphy and structure to those of the Brunswick Mine area. They include narrow beds of fine acid volcanic material interpreted to be metatuff and volcanogenic metasediments. The massive sulphide ore body at Key Anacon lies immediately above these acidic rocks, in association with other chloritic, sideritic or magnetic iron-rich metasediments. The iron formation, which is similar to that associated with other orebodies in the district, is overlain by massive andesitic material. Four phases of structural deformation have been recognized in the Key Anacon area; they are similar in intensity and style to those of the Brunswick No. 6 mine area. The orebody lies in a zone of complex isoclinal folding along the flank of a major F2 fold (Key Anacon Syncline) and in general appears to be stratiform. The ore occurs in probable F2 parasitic folds, and this suggests a complicated structural geometry superimposed on the original beds. The general similarity of the mineralization at Key Anacon, together with its occurrence with other iron-rich metasediments between a footwall of acid volcanic material and overlying andesitic rocks, is suggestive of stratigraphic time-equivalence with the Brunswick zone . If so, the metavolcanics at Key Anacon might have been derived either from a center within the main volcanic pile to the west or from a smaller local center active at the same time. Alternatively, the Key Anacon ore could have been formed during a much older volcanic cycle. The solution to this aspect of the problem is the subject of a continuing study.

Jan 1, 1978

By Bo-Hyun Kim

Outline ? Strainburst criteria and hypotheses adapted for this study. ? Influence of excavation method on rock mass properties. ? Excavation disturbance factors vs. deformation modulus, etc. ? Estimation of blasting damage zone around excavation. ? Considerations of energy on burst-prone ground. ? Literature review & closed form solution. ? Numerical simulations. ? Summary and future works.

Oct 1, 2010

By Dirk van Zyl

The world is consuming more and more electronic products every year. This has caused a dangerous explosion in electronic scrap (e-waste) containing toxic chemicals and heavy metals that cannot be disposed of or recycled safely. But this problem can be avoided. We are pressing leading electronic companies to change; to turn back the toxic tide of e-waste. Every year, hundreds of thousands of old computers and mobile phones are dumped in landfills or burned in smelters. Thousands more are exported, often illegally, from the Europe, US, Japan and other industrialized countries, to Asia. There, workers at scrap yards, some of whom are children, are exposed to a cocktail of toxic chemicals and poisons.

May 1, 2008

By T. Crivits, I. Bellemans, K. Verbeken

In the metallurgical industry, furnace cooling is often employed to enhance furnace lifetime. Hence, the pyrometallurgical phase comes in close contact with a non-air coolant. The proximity of the pyrometallurgical phases to the coolants may lead to dangerous situations. In case of a breach of the cooling circuit, the contact between a hot and a cold liquid may cause a vapour explosion. The outcome of this vapour explosion includes a pressure wave which could result in damage to the furnace, bodily injuries or even casualties. To prevent such dramatic events, the origin of vapour explosions is currently being studied in more detail. For this purpose, OpenFOAM was used to perform Computational Fluid Dynamics (CFD) simulations. In a first step, simulations were run to get a better idea of the influence of the compressibility on the simulations. The obtained results help in getting a better insight on the need of computational power, and possible numerical errors using compressible or incompressible solvers in future simulations. In a second step, systems without vapour explosions were simulated and compared to experimental results with mercury and aluminum. INTRODUCTION Humanity started using metals for tools around the Chalcolitic (~7400 cal BC), when copper was melted in small furnaces (Radivojevic, Rehren, Farid, Pernicka, & Camurcouglu, 2017). Nowadays, metallurgy has grown into a major industry and it has become impossible to imagine society without metals. In the pyrometallurgical industry, coolants (low temperature liquids, for example water) and pyrometallurgical phases (high temperature liquids, such as slags, mattes and alloys) are typically present in close proximity of each other. The interaction between these two phases can have catastrophic consequences (Tveit et al., 2008; Ferguson & Zsamboky, 2017). A vapour explosion may occur as the consequence of the rapid evaporation and expansion of the coolant. Whereas the volume of a gas increases linearly with the temperature (approximately a factor four by heating from 100°C to 1300°C), a simple calculation of the ratio of the two specific volumes shows that evaporation causes the volume of water to increase by a factor of 1700 at 100°C and ambient pressure (Table 1 and equation (1)), a number that was also found in literature (George, Nexhip, George-Kennedy, Foster, & Walton, 2006). The volume change occurs so fast that it resembles an explosion, hence the name vapour explosion. Such an explosion at industrial scale can cause economical losses, bodily injuries or even fatalities.

Jan 1, 2019

By Marke Wong

? Vietnam?s economy is growing so fast that gross domestic product (GDP) growth remained above 8% in 2005 and exports are rising steadily at 25% per year. ? Demand for electricity is expected to increase 18% per year through 2010 requiring an additional estimated 7,547 MW before 2010 ? Domestic coal demand is expected to be over 45 Mt by 2010. ? The Quang Ninhcoal deposits are estimated at 6.5-7 billion tons (350m) Vietnam News Agency. Saturday, May, 6, 2006. ? National resources are now estimated at 10 billion tonnes; not including a relative new coal bed discovery estimated at 210 billion tonnesin the Red River Basin.

May 1, 2006

By D. L. Marchioni

"The detection and quantification of the degree of weathering is an important aspect of coal exploration and mining. Tests for weathering which are suitable for the exploration camp should be fast, simple, and require minimal equipment and operator expertise. In this study, two tests which fulfill these requirements were evaluated using samples of Western Canadian coals. These tests, one based on the pH of a coal slurry and the other on the flotation of coal in a water/diesel oil mixture, do not appear to give consistent results and are not recommended as ideal weathering parameters.IntroductionThe weathering of coal results in a deterioration of those properties which render it suitable for use in industrial processes. Consequently, the detection and quantification of the degree of weathering is an important aspect of exploration and mining. Frequently, decisions related to the depth of the weathered zone must be made at the exploration camp and, therefore, tests for weathering which are fast, and require relatively inexpensive and portable equipment and minimal operator experience, would be very useful. The aim of the study reported here was to evaluate two tests used by U. S. Steel Corp. to detect coal weathering and which satisfy the requirements for use in an exploration camp. The study is a continuation of a more extensive examination of the detection of coal weathering by various methods, reported elsewhere (Marchioni, in press)."

Jan 1, 1981

By Tetsuya Yumoto, Toshikazu Shiratori

Information on the elements contained in E-Waste is important from the viewpoint of recycling. We analyzed several components of waste electrical and electronic equipment (WEEE) collected from citizens. The distributions of the minor metals in WEEE were determined with elemental mapping and chemical analyses. The annual change in elemental composition was investigated by analyzing equipment manufactured in different years. The information will be of use for separation techniques required for future advanced recycling.

Jan 1, 2011

By A. F. Gregory

"AbstractA resumé of aerial radiation survey studies performed by and for Eldorado Mining and Refining, Limited, since 1943 is presented. Flight tests were initiated in 1947 and were followed .by intensified use and study of Geiger counters and other radiation detectors. Development of an aerial scintillation counter began in 1948, but •a sensitive large crystal unit was not available for exploration purposes until 1950. Modifications of this unit have been used in all subsequent surveys.For the Eldorado detector, several limiting conditions were established for successful radioactivity detection, the most important being that natural vein exposures can only be assuredly detected .at distances less than 150 feet. Sedimentary and pegmatitic radioactive occurrences can be detected at much greater distances. A helicopter investigation technique appears to •have •a useful prospecting potential.IntroductionAerial radiation surveys were first proposed in the early 1940's. However, it was not until 1949 that airborne detectors were extensively used in the search for radioactive minerals. Eldorado has flown about 50,000 miles of exploration flights, exclusive of tests, using a variety of •detectors and aircraft. Considerable data have •been gathered for .the evaluation of the several techniques employed. Much of the early work was performed with the co-operation of the National Research Council of Canada ( 1). More recent work was done in conjunction with the Commercial Products Division of Atomic Energy of Canada, Limited. The Development Department of this latter corporation designed and built the scintillation counter used in recent Eldorado surveys."

Jan 1, 1955

By S. Wood

"Plastic Filled Valley (PFV) wire rope represents a significant development over the design of conventional wire rope. A sealing thermoplastic is impregnated under controlled conditions of temperature and pressure into a conventional lubricated wire rope to produce a lattice of plastic which surrounds and separates the strands from each other and from the core. Metal-to-metal contact is thereby alleviated and the lubricant is sealed in. The wear resistance, rope breaking load, fatigue resistance and crushing resistance are all increased. The result is a rope which offers exceptional service life.Laboratory tests carried out in Canada and at the University of Stuttgart, in West Germany, confirm the increase in fatigue life. The field trials conducted so far have indicated that the results obtained in the laboratory can be duplicated in the field.IntroductionIn times of double -digit inflation, the consideration given to operating costs throughout industry commands considerable attention. The same can be said of the mining industry. A set of large-diameter wire ropes used on the huge draglines in strip mining can cost in excess of $100,000. Because a machine may use three sets of rope s each year, it is clear that the costs of wire rope can contribute a considerable percentage to any operating budget. As wire rope is a product which is used extensively throughout the mining industry, it would appear timely to turn our attention to any ""Method of Extending Wire Rope Service Life"" in order that wire rope life can be optimized and wire rope costs can be minimized."

Jan 1, 1982

By L. Voisin, G. Damm

"In order to develop a new pyrometallurgical process for eliminating detrimental arsenic and antimony from the impurity-rich matte produced from copper concentrate, and for treating the occasionally generated speiss in nonferrous smelting processes, the phase relations in the Fe-Cu-S-As-Sb system saturated with carbon at 1473 K were investigated. The distribution of elements between the condensed phases at the miscibility gap, where three equilibrated phases of iron-rich alloy, copper-rich alloy, and matte coexist, were also studied. The investigation was carried out by performing a series of laboratory scale experiments in an electrical furnace at 1473 K, followed by a quenching method on the final stage. The samples obtained from the experiments were analyzed by using Inductively Couple Plasma (ICP), Atomic Absorption Spectroscopy (AAS) and Carbon Infrared Spectrometry (CIS) techniques.The results were compared with previous investigations for the Fe-Cu-S-As-C and Fe-Cu-S-Sb-C systems and discussed on the basis of the molar fraction distribution for both arsenic and antimony in the matte phase at five different matte grades. It is expected that by using this phase separation technique it might be feasible both, the cleaning of a complex copper matte and the elimination of arsenic and iron together with an acceptable amount of antimony into the iron-rich alloy phase, which can be discarded as a harmless and smaller deposit."

Jan 1, 2014

By M. Isac, R. I. L. Guthrie, S. Ge

The Al-Mg-Sc-Zr alloys have shown exceptional potential as structural materials for transportation applications. These alloys have proved to be good candidates to be processed as thin strips via the Horizontal Single Belt Casting (HSBC) process. The HSBC process is a near-net-shape casting technology, which involves casting molten metal directly into thin strips, close to the final product thickness, at high cooling rates. It offers an efficient, economical and environmentally-friendly approach to the production of metal strips. Fluid mechanics and associated heat transfer are important aspects of any casting process, and the novel HSBC process is no exception. Three dimensional Computational Fluid Dynamics (CFD) simulations using ANSYS FLUENT 14.5 were performed, in order to assess the importance and effects of the various operational conditions of the HSBC process. This enabled process parameter optimization. Numerical predictions were validated against experimental casting results.

Jan 1, 2014