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By M. Razavi

This investigation is part an overall investigation on the effect of sodium silicate on the properties of the mine backfill. The results presented will highlight the effects of binder dosage, sodium silicate concentration, and pulp density on the performance of stabilized sodium silicate-fortified sand pastefill samples. Binders implemented for these experiments consisted of cement, slag, and sodium silicate in various proportions. The binder content varied from 3 to 9 wt% (total dry weight) and sodium silicate concentrations was adjusted at 2 and 4% (total binder weight). Moreover, pulp density was adjusted to values between 80 and 83 wt%. For completion of the aforementioned phase of the study, series of sand pastefill test samples were prepared and cured for 28, 56, or 120 days, in a humidity and temperature controlled room. The specimens were tested for uniaxial compressive strength (UCS). In order to study the effect of sodium silicate on microstructures of stabilized sand pastefill, some MIP tests were conducted on selected samples. The results of this investigation evaluate the use of sodium silicate as a partial replacement of cement in stabilized backfill. The analyses of the results demonstrates that, with an increase in binder content and a decrease in pulp density, the UCS values of sand pastefill samples increase. Further more, the results indicate that increase in addition of sodium silicate does not necessarily result in higher strength minefill.

May 1, 2007

By R. A. McIvor, R. S. Rafuse

"INCO Limited purchased a custom designed mobile hoist rope winder/tensioner in 1988 from TimberLand Equipment Limited to handle Large hoist ropes and serve as an emergency hoist. This paper describes the operation of the winder/tensioner and some of the different applications that the machine has been used to handle large loads.IntroductionINCO Limited operates 24 mine hoists in the Ontario Division and has approximately 50 miles of mine hoist rope hanging in the shaft plus an equal amount on spare reels. The mine hoist ropes range in size from )( inch to 2.305 inches in diameter with the majority being 1 3/4 inches and above. Prior to the procurement of a new high powered winder/tensioner in 1988, the mine hoist ropes were handled with a variety of methods and equipment using hydraulic or pneumatic powered reel winders. The largest such reel winder has a pull rating of 8000 Ibs and travels approximately 40 ft/min. Head ropes for the tower mounted friction hoists were installed and removed using a magazine on the hoist drum to wind and unwind the rope because the loads were greater than the capacity of the existing machinery. It was recognized that a large high capacity machine would improve the productivity for handling the larger hoist ropes and a feasibility study was undertaken to determine the parameters for such a machine."

Jan 1, 1995

By A. Michalkow

DELN ITE Mines Limited is located in Deloro township, on the west end of the south break of the Porcupine Camp. Mining operations are currently being carried out on the downward extension of a system of quartz veins in an andesite zone. This zone has been followed from surface to the present bottom level of 5,250 feet. The changing mineralogy of the vein system has involved an increase in tourmaline content from the surface downwards, so that the veins at the lower levels are composed of dark brown quartz-tourmaline. The drilling problem presented by these extremely hard veins was partially alleviated by the development and adoption of a one-inch drill bit. All blast-hole drilling is now done with the one-inch bit, without any difference in hole spacing.

Jan 1, 1962

By G. S. Barry

INVESTIGATIONS to date have shown that, should there be the need or the appropriate economic stimulus, Canada's mineral resources are sufficiently extensive to allow considerable expansion of its non-fuel mineral industry, during the remaining part of this century and possibly beyond (1, 2). The availability of sufficient capital will be one of the critical factors which will determine whether this potential will be fulfilled. The following analysis centers on the capital requirements of the Canadian non-fuel mineral industry under one set of basic assumptions of capacity growth, cost of new and replacement capacity, rates of depletion and depreciation of mines and plant, and the cost of exploration and infrastructure. Mindful of the fact that exploration and development will not thrive in Canada unless a very positive approach is taken, the writers make no apologies for being "optimistic" about long-term production prospects. Furthermore, in the event that world demand does escalate as anticipated and the forecast realistically attainable levels of Canadian production are not reached, then Canada will not have reaped the full range of economic benefits available, and opportunities will have been lost. Projections for Canadian production between 1976 and 2000 are essentially based on the forecast published in the 1974 paper, "Towards a Mineral Policy for Canada - Opportunities for Choice (3), with some updating on the basis of recent developments.

Jan 1, 1977

By Cheryl L. Allen

Increasing energy costs associated with mining have become an issue that must be addressed by industry to ensure sustainable production. As underground mine ventilation systems account for 40% to 50% of a mine?s total energy requirement, initiatives to maximize their efficiency have been introduced worldwide. A control method known as Ventilation-On-Demand (VOD), which adjusts the ventilation system by responding to the activities of mine personnel and air quality, has been commissioned at Vale?s Coleman Mine. This initiative is an effort to reduce energy consumption, maximize efficiency of the ventilation system while ensuring air quality. There are five control strategies that can be executed with the VOD control system in place at Coleman Mine: Manual real time control Time-of-Day Scheduling Event-based control Environmental control Activity Based Control/Tagging This paper describes the system, control strategies and impact on energy consumption and flexibility of airflow distribution as applied at Vale?s Coleman Mine.

May 1, 2011

By Jiuhua Xu, Shuiku Jia, Weiren Sun

"The Jinqingding gold deposit, situated in the east Jiaodong Peninsula of Shandong province, is typical of the pyrite-quartz vein gold deposits in the Muping-Rushan gold belt of China. The gold deposit is controlled by a great NNE fracture zone and is composed of several lenticular orebodies within the fracture rone occurring in the Kunyushan granite massif. The Kunyushan granite massif was formed by the replacement of the Archean Jiaodong group.The main minerals associated with gold are pyrite, chalcopyrite, galena and sphalerite; the gangue minerals are dominated by quartz, sericite, microcline and calcite. The mineralizing event can be divided into four stages: (1) pyrite-quartz; (2) quartz-pyrite; (3) siderite-polymetallic sulfides; and (4) calcite-quartz. Gold occurs mainly as native gold and electrurn in stage I and stage II. There are some evident differences between pyrite from major stages of gold mineralization and that from minor stages; these include differences in crystal forms, size and composition of fluid inclusions.Wallrock alterations consist of sericitization, silicification, pyritization and potash-feldspar alteration. Five alteration zones can be distinguished from unaltered granite (zone 0) to vein lodes (zone IV). Au and Ag increase rapidly from zone 0 to rone IV, Cu increases continuously, while Pb and Zn increase slowly. R-type geological factor analysis indicates that the Au, Ag, Cu, Pb and Zn bear a close relationship to wallrock alteration."

Jan 1, 1994

By P. H. Shipway, D. G. McCartney, H. Saghafifar

The microstructural changes during thermal ageing at 650ºC in the interfacial region of Alloy 625 weld overlay on a 2.25Cr-1Mo steel was evaluated. Optical microscopy, scanning electron microscopy in SE and BSE modes, electron probe microanalysis and hardness mapping were used to characterize as-welded microstructure and its changes during thermal ageing and precipitates of interfacial region. Carbon migration across the interface was recognised as a major issue. A region of 300 µm wide adjacent to the fusion line, which was found harder in the as-welded condition decarburized during thermal exposure. Studies revealed that this region transformed to a soft region containing large ferrite grains and micron-sized carbides. In the weld overlay, a 50 µm wide hard band (over 650 Kgf mm-2) adjacent to the fusion line formed and carbide precipitates were observed along grain boundaries. Carbide precipitation mostly occured in the 150 µm wide region close to fusion line.

Jan 1, 2017

By Rodney S. Read

Both crystalline and sedimentary rocks are being considered to host a deep geological repository (DGR) for nuclear fuel waste in Canada. In the past several decades, considerable research has been conducted around the world to better understand geomechanical processes associated with development and long-term performance of a DGR. The Nuclear Waste Management Organization?s (NWMO?s) technical research and development program is examining a number of potentially suitable rock formations to support implementation of Adaptive Phased Management, Canada?s approach for long-term management of nuclear fuel waste. Rock engineering will play an important role in siting, design, and construction of a DGR for nuclear fuel waste. Post-construction activities such as excavation maintenance, monitoring, decommissioning, and closure will also involve rock engineering. The type of host rock selected for a DGR will influence the scope of rock engineering activities and related research requirements. This paper outlines key rock engineering aspects to be considered in developing a DGR in sedimentary rock.

May 1, 2009

By K. Fumimura, T. Nishimura, M. Kohno

When applying numerical techniques to problems of deformation of rocks, the body to be analyzed is divided into small portions and is represented by a system of points linked together with the neighboring points. In the so-called distinct element modeling, the particles in the system are directly connected by springs and a contact law is used to specify forces on the particles to simulate the mechanical behavior of the body. The relation between the spring stiffness and commonly measured material properties, such as the Young’s modulus and the Poisson’s ratio, should be known a priori. For the general case of a random packing of particles, the relation is found by means of a process in which a system of particles and set of parameters are prepared to simulate a set of specimen-size test and then the input parameters are chosen to match the measured material properties. The validity of the numerical result is only demonstrated by comparison model behaviors with the measured responses. The process includes trial-and-error manner, therefore, no model is complete to reproduce the mechanical properties. In this paper, a relation between the spring stiffness and the elastic constants; the Young’s modulus and the Poisson’s ratio, is introduced to a three-dimensional distinct lattice spring method. Two simple numerical examples will be presented to demonstrate the performance of the method with the procedure for the determination of the spring stiffness.

Jan 1, 2015

By J. O. Marsden

Over the past decade, the copper industry has been through an extended downturn followed by several years of sustained high copper price. A number of new technologies have been developed over the past 10 years aimed at reducing costs by decreasing energy, labor, and materials requirements, or by increasing metal recovery. The energy intensity of different copper extraction routes and different technologies varies considerably and this has a significant impact on the economics of extraction. Based on average ore grade materials, the total energy for the extraction of copper typically varies from about 24-26 MJ/lb (6.7-7.2 kWh/lb) for the mining, crushing, milling, flotation, smelting and refining route to about 14¬16 MJ/lb (3.9-4.5 kWh/lb) for the mining, crushing, heap leaching, solution extraction and electrowinning route. New technology developments are providing opportunities for significant reductions in energy consumption for copper extraction, representing energy savings up to 20-25% in some cases. In addition, in many cases, these new technologies have introduced environmental, safety and health benefits over the incumbent technology. Some of these technology developments have been more successful than others, and many hold great promise for application in the coming decade. This paper provides an overview of the technology developments that have occurred, and explores the underlying reasons behind successful implementation.

Jan 1, 2007

By Max W. Ball

YOU have been kind enough to ask me to speak to you on "The War and Anglo-American Relations." A speaker always takes the liberty of putting his own interpretation on the scope of his subject. I am going to exercise that privilege, and try to look back over a generation of Anglo-American relationships and forward beyond the present war. I should like particularly to consider responsibilities as well as relationships. A more accurate caption for what I am going to say would be "Anglo-American Responsibilities.?? THE WAR WILL BE WON I am assuming that sooner or later we shall win this war. History and economics point to the same conclusion, that Germany has attempted the impossible and that the seeds of defeat are already sown. As to one ecof1:omic factor, I am already on public record as believing that Germany's oil supply is inadequate for the war she has launched. That opinion is unchanged. Aside from such tangible factors, moreover, I am convinced that the spirit of freedom is unquenchable, and that no combination of powers will be able to rout it from the British Commonwealth of Nations and the United States. Stronger even than this conviction is my faith in a God who will not suffer the defeat of man's aspiration to be master of his own soul. I am sure that all of you share that faith, and that we need not argue it. We can start with the assumption that the war will end in victory. The subject we are to consider, then, is the relationship of the English-thinking peoples during the conflict, and their joint responsibilities in the difficult days that will follow it. A CANADIAN-AMERICAN No talk on such a subject is worth listening to unless the audience knows the background and fundamental beliefs of the speaker. No human statement stands alone; behind and beside and within it are the ideals and the bias of the man who makes it. Because I am a stranger to most of you, I am constrained to talk about myself before I talk about more important matters. The review may be profitable, not because of the subject, but because it may illustrate the evolution of an attitude toward England.

Jan 1, 1941

By Chris Twigge-Molecey

Demand for metals will continue to grow as global population numbers and prosperity levels steadily increase. Consequently, there will continue to be a need to design and construct new metallurgical plants. Business success in general requires projects to be financially successful and return appropriate value to their owners. However, in the metals industry, private and public sector financing sources have become very sensitive to the perceived inability of projects to contain costs and meet other business objectives. Thus, the capital for projects has become more difficult and expensive to obtain. It is instructive to note that Ernst and Young (2011) identified that: “Delivery of predictable project results bestows competitive advantage and market confidence to those corporations who successfully instill this discipline”. The implication for future projects is that they must be systematically developed to minimize perceived risks—and more importantly—to demonstrate that the risks are managed to achieve the business case. Then, provided that the project has been developed in a well-structured way, project success can again be defined as a project with: a final cost within 10% of the budget approved at the end of FEL3, when the project is properly defined and the permit conditions are agreed upon; a start-up date within three months of the definitive, scheduled startup date; production levels at 85% of design capacity within a year of starting commercial operation; production meeting the target environmental restrictions; and with zero lost time accidents during construction and startup. The plant design is one of many integrated activities required to achieve these objectives. This book represents a valuable link between the existing engineering literature that encompasses a wide range of engineering fundamental textbooks and design manuals and the project management literature such as the Project Management Body of Knowledge, or PMBOK® (Project Management Institute, 2014). It is evident throughout this book, that the design team is a small but essential part of a much larger project team comprising the project management, construction management, and construction contractor staff. Design activities must be regarded and managed as part of the integrated whole, with two fundamental links throughout the design process:

Jan 1, 2015

By M. P. Rennick, D. M. Burton

The Murray Brook massive sulfide deposit, which was the first geochemical discovery in the Bathurst camp, is one of the largest sulfide deposits in the area. The massive sulfides are hosted by quartzose metasedimentary rocks in the lower part of the Ordovician Tetagouche Group. This thick succession of sedimentary rocks is overlain conformably by felsic volcanic rocks, and is structurally overlain by mafic volcanic rocks. The massive-sulfide body is polydeformed, but primary metal zoning is still discernable and may permit future exploitation of discrete lead-zinc and copper zones. Although it was discovered in 1956, the deposit was not developed until 1989, when Murray Brook Resources commenced processing of gossan containing precious metals. Recovery of gold, silver, and mercury is accomplished by indoor vat leaching on a year-round basis.

Jan 1, 1992

By A. J. Hyett

Due to the ongoing revolution in electronics and communications more cost-effective geotechnical instruments can be manufactured using digital technology. This new generation of digital instruments have embedded microcontrollers that provide highly accurate and reliable measurement of geotechnical behaviour in real world units that can be immediately interpreted. Digital measurements can be transmitted across existing mine-wide wireless communication networks, interfaced directly with infra-red enabled PDA?s or PC?s, and parsed to memory by low-cost data-loggers.

Apr 1, 2005

By Patricia Dillon

EHS Management Standards Communication and Reporting (8) ! Establish processes for internal and external communications ! Designate responsibilities for communication with COI ! Report as defined by senior management ! Report annually to employees, shareholders, COI on EHS and social performance Community Rights and Public Consultation (9) !Identify COI?s and establish process to hear concerns !Acknowledge and respond to complaints !Support local communities !Plan for closure and conduct public consultation !New projects include identification of COI?s, concerns to be considered in design

May 1, 2004

By A. P. Paiva

The solvent extraction properties exhibited by some /V,N'-tetrasubstituted malonamides to efficiently and selectively recover iron(III) from concentrated chloride leaching solutions can be found in the recent literature. The iron(III) extractive chemistry exhibited by some of these derivatives is revisited, in order to compare their chemistry with that shown by a few of the new malonamide compounds. The generally good extraction efficiency towards Fe(III), from >4 M hydrochloric acid solutions, and the relative ease of Fe(III) stripping by distilled water are remarkable findings that are confirmed for the malonamide derivatives described in this work. Furthermore, additional data regarding their selectivity towards Fe(III) extraction over several base metal ions and their behavior when subjected to successive Fe(III) extraction-stripping tests are also presented and discussed.

Jan 1, 2006

By F. Habashi

Magnesium is the eighth most abundant element in the earth's crust, It occurs in nature in sea water, brines, and a number of minerals, Metallic magnesium was first isolated by Humphry Davy (1778-1829) in England in 1808 via electrolysis of anhydrous magnesium chloride with a mercury cathode, Antoine Bussy (1794-1882) in France extracted the metal in 1828 by reducing fused magnesium chloride with metallic po¬tassium vapour, The first industrial production of magnesium by electrolysis of molten carnallite began in 1886 in Hemelingen in Germany, In 1940 Lloyd M, Pidgeon (1903¬1999) in Canada pioneered the first industrial metallothermic magnesium extraction plant based on the reduction of dolomite with ferrosilicon under vacuum, Since then the magnesium industry developed further and a variety of processes are presently used.

Jan 1, 2006

By Z. D. Hora

Sand and gravel resources of the southern coastal region of British Columbia may be linked to various episodes of Wisconsin glaciation. During Wisconsin and probably earlier times, the Fraser Lowland and coastal areas were subjected to repeated glaciations separated by non-glacial intervals. Each major glaciation was accompanied by isostatic and eustatic changes in sea level up to 200 m or more. As a result, the Lowland was covered by the sea during much of Quaternary time. Because the Fraser Lowland is surrounded on two sides by high mountain ranges, glaciers terminated in the sea during their maximum advance. Therefore, meltwaters released during deglaciation, together wit h retreating glacier ice, could produce widespread and extensive sand and gravel deposits both along the coast and throughout the Fraser Lowland and adjacent areas.

Jan 1, 1984

By J. Jung, W. Keller, A. Zucht

"The agitator design for nickel high pressure acid leach autoclaves (HPAL) is critical with regard to the process result, i.e., the recovery rate. Further considerations during the design phase are the avoidance of acid hot spots which reduce the lifetime, due to corrosion of the wetted parts, including components manufactured from titanium. Besides the process knowledge to design HPAL autoclaves, tools such as, Computational Fluid Dynamics (CFD) supplemented by lab testing allow the design of optimized agitation systems. This paper describes the effect that different feed point locations have on instantaneous blending of the reactants. Furthermore, experiments and CFD show where abrasion issues might occur and how to obtain information about the static and dynamic forces acting on internals. We show how simulations can be validated by lab testing to ensure that the CFD models are applied in an appropriate way.INTRODUCTIONAgitated systems in hydrometallurgical processes have to comply with multiple process tasks and in many cases have to withstand extreme operation conditions such as pressure up to 50 bar, elevated temperatures of up to 250°C and exposure to very acidic or alkaline environments and abrasive ores. The process tasks range from instantaneous mixing of reactants, homogeneous suspensions of up to 65% wt. solids with coarse and heavy particles, enhancing the solid-liquid mass transfer for leaching, dispersing large volumes of reactants (gas-liquid, liquid-liquid mass transfer) and moreover to transport generated heat e.g., from exothermic reactions through the vessel walls or internal heat exchangers if required. For economies of scale, agitator systems have reached sizes of 5000 m³ for large open leach tanks with impeller diameters of approx. 6 m, while autoclaves nowadays have exceeded 5.5 meters in diameter with a power demand for a single compartment drive between 300 - 400 kW. In parallel all process industries require a more efficient use of resources, to generate less by-products and higher yields, while ore-bodies tend to be less qualitative and new process routes (e.g. direct leach) are developed. Besides all these facts the mixing solution must be robust and economic. In this paper we want to address our approach in the development and designing of HPAL agitation equipment."

Jan 1, 2012

By S. A. Sadough vanini

In this paper the influence of temperature on the flow behavior and rheological characteristics of an A356 alloy in the semi-solid state using backward extrusion process are studied experimentally and numerically. Simulation process is done by dynamic explicit in ABAQUS software for each forming condition. A cooling slope treatment was employed in order to obtain a non-dendritic microstructure. Experiments were performed in 5 temperatures and 4 different wall thicknesses. In the low forming speeds, liquid fraction had time to escape from solid phase forward the samples? wall. This condition was the main reason for the segregation phenomenon seen in the base and walls. Viscosities were determined using the force-displacement graphs obtained form back-extrusion tests. As observed experimentally, in a constant temperature, increase of shear rate resulted in decrease of alloy viscosity exponentially. Raising the temperature increases the liquid fraction hence reduces the semi-solid alloy viscosity. The results of experimental and simulation are compared and there is a good adaptation.

Oct 1, 2011