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By N. R. Andrade-Gonzalez

The present work was performed on four alloys containing Al-6 2 wt pct Si-3 5 wt pet Cu, with magnesium in the range of 0.02-0 40 wt pct, and strontium in the range of 0-165 p p m Tensile bars were cast in a permanent mold (ASTM B108-160) and heat treated at 495°C for 4 hours, followed by quenching in hot water. Two different artificial aging temperatures were applied at 180 °C and 220 °C for times from 0 5 h up to 8 h Tests were conducted with the intent of determining how the mechanical properties of an aluminum-based 319 alloy are affected when aging time and temperatures are varied In general, it is seen that the alloy does not exhibit the common peak-overaged aging condition due to the presence of several coexisting phases, indicating that they form through complex eutectic reactions late in solidification.

Jan 1, 2004

By J. D. Robertson

An in situ water sampling device has been developed to measure biologically-available or “labile” metals in natural waters and effluents. The active mechanism involves the use of a polyacrylamide gel layer to quantitatively control metal transfer to a trace-metal-adsorbing, gel-imbedded resin. Because the resin only adsorbs free metal ions (the gel sampler methodology is a kinetic speciation technique), and because metal bioavailability is related to the free-ion activity, the device provides a direct measure of the biological-availability of metals in the environment sampled. The prototype consists of a layer of ion-permeable polyacrylamide gel which separates the solution to be sampled from an ion exchange resin. Because approximately 90% of the polyacrylamide gel is water, mass transport through the gel is diffusion-controlled, and is therefore well defined. Metal ions are rapidly bound by the resin, creating a steep concentration gradient in the gel. The amount of labile trace metal that accumulates on the resin can be related directly to the concentration of the metal in solution, the exposure time and the molecular diffusion coefficient of the labile species. In addition, the passive nature of this device affords it the potential to address many of the limitations presented by conventional sampling methods, such as sample contamination introduced during collection or filtration and changes in trace metal speciation prior to analysis. Laboratory studies and limited field trials indicate that the sampler behaves as anticipated and illustrate that biologically- available metal concentrations in many environments are a small fraction of the total concentrations and often significantly less than the dissolved concentration. The implications of this on regulatory criteria are discussed. Additional field trials and correlation with bioassays are currently underway.

Jan 1, 2000

By A. Noël, R. Lapierre, M. Provencher

"Modem aluminum smelters are facing significant operating cost pressure. Key methods used by smelters to manage this pressure are automation and production-information systems to optimize processes, manage quality, anticipate problems and reduce operating costs. In 2002, Aluminerie Alouette Inc. began its Phase II Expansion project, and retained the joint venture of SNC-Lavalin and Hatch (SLH) as its engineering, procurement and construction management (EPCM) team. Alouette had the distinction of being one of the most efficient aluminum smelters in the world. Alouette already understood the importance of systems integration in project delivery. For Phase II, key objectives were identified to ensure ""a state of the art"" integrated architecture that would support Alouette's production goals to integrate the existing facilities with the expansion, to form a single efficient facility and meet project schedule and budget targets. Achieving those objectives within the context of a large project often creates major challenges due to the nature of the traditional EPCM delivery model, which relies on several vendors and third-party-systems integrators. In this case, an integrated Alouette-SLH team was made responsible for all aspects of the systems integration, taking over the task from most suppliers. The integrated team was responsible for delivering an automation system and plant-wide-production IT system for the new facilities while accommodating migration for the existing systems. Through the use of rigorous methodology and advanced state of the art technology, the IT and automation strategy led to significant value creation and is recognized today as one of the key factors of the project's success. The primary results were: fast and efficient start-up of facilities, due to quality programming and implementation; a plant able to operate as a single entity; automation and IT systems delivered before time and under budget; standard programming methods implemented throughout the plant; and reduced and simplified maintenance."

Jan 1, 2006

By John Hughes

1. De Beers, Diamonds and Canada 1.1. De Beers was founded long ago (1888, the same time that Canada became a country) in a rural mining village in South Africa. Today, we employ 22,000 people across 19 countries and have 14 mines including open pits, shafts, beach-sands and seabed. 1.2. Last year our sales were US$5.7 billion and our total production amounted to 47 million carats which means a 40% global market share. For the Kyoto buffs in the audience, the company consumes 66 million cubic metres of water per annum, 210 million litres of hydrocarbon fuel and 1,600 GWh of electricity. Stats are good, but aren?t as expressive as a movie. This one is 2 minutes long, which is quicker than I could elaborate. (Video 1 - 2 minutes) 2. De Beers in Botswana is the leading source of diamonds 2.1 Today Botswana is the Jewell in the Crown. There are three big open pits that enjoy economies of scale that make them the lowest cost producers. Last year 60 million tonnes of overburden and 30 million tonnes of ore were moved in Botswana alone. Botswana produced 31 million carats, compared to 14 million carats in South Africa and 2 million very high quality carats inn Namibia. 3. Diamond Mines provide feedstock? ?.to jewellery stores

Apr 1, 2005

By C. Bourgoin

"The factors constraining productivity in the mining of narrow vein ore deposits are numerous and often interdependent. This paper concerns mining techniques capable of reducing some of these constraints in the case of vein deposits whose dip is less than 45 degrees. Modifications of conventional mining methods as well as suggested new developments are presented, as are matters pertaining to the mechanization of operations as a mean of increasing both productivity and work safety. IntroductionThe mining of vein deposits, whose width (thickness) is generally less than 2 metres and whose dip is often variable, calls for the use of varying stoping procedures as well as appropriate infrastructure and equipment. In the case of intermediate dips (15 degrees to 45 degrees), it is generally conceded that the degree of mechanization is limited and that ore removal via gravity is impossible. This paper proposes certain innovations in matters of equipment use and stoping methods, together with certain technical data pertaining to the application of these new procedures Stoping MethodsTo mine vein deposits, one must choose a method that can adapt to irregular ore limits and allow, as well, for good ore recovery with as little dilution as possible. In addition, it is important to minimize development work in waste rock. In principle, one selects a method that is both safe and profitable; this method will be defined mainly by the nature of the vein deposit and its dip, by the competency of the rock formations and by certain technical considerations. Moreover, the stoping procedure in a given deposit may well change with time as a function of new layouts or new equipment."

Jan 1, 1994

By E. G. Joe

The continuing increase in costs for power and fuel are affecting significantly the cost of milling Canadian ores. In order to ascertain the scope and source of energy consumption in Canadian mills for further energy conservation opportunities, CANMET, in cooperation with the Canadian Mineral Processors, carried out a detailed survey on the metallic mineral processing plants. Sixty-seven mills representing almost 300 million tons of annual capacity participated in the survey. The results indicated that, in general, copper and iron ore mills, representing the bulk of the tonnage, consumed relatively low levels of energy per ton. Nickel-copper, zinc-copper and lead-zinc .ore mills were moderate in energy consumption, and uranium and some copper-lead-zinc mills reported much higher energy consumptions due primarily to the increased heat requirements of the ore pulp. Although plant heating costs varied somewhat with location, it was apparent that the lowest heating costs were achieved by those plants built with proper insulation and energy conservation design. If the cost per million British thermal units is taken as $2.00, the mill energy costs generally ranged from 40ft to $1.20 per ton.

Jan 1, 1979

"This paper describes an alternative method of vehicle control which uses a micro-processor to control the field current and armature voltage concurrently. The field tests carried out and the conclusions drawn from the basis of the paper.IntroductionIt is generally accepted that the main obstacle to a greater use of electric vehicles is the relatively poor range and performance when compared to alternatives such as diesel and petrol-engine vehicles. Much effort has been applied to the problem of increasing the energy storage density of batteries and considerable improvements are now being reported.Improvements in the efficient use of the stored energy, although unlikely to achieve the necessary increase in range and performance for a widespread acceptance of electric vehicles, can nevertheless make a useful contribution. Because the improvement in efficiency is achieved by a reduction in losses, it follows that the temperature rise in drive-train components is reduced. These advantages, coupled with the increasing cost of energy, make improvements in the efficient use of the stored energy desirable, if not absolutely necessary. To achieve this with the large and rapidly varying loads encountered during the operational use of a vehicle will require a more flexible system of control than that provided by the current limit. This paper describes an alternative method of control which uses a micro-processor to control the field current and armature voltage concurrently.The value of these parameters is selected to supply the power demand at the motor shaft, with the minimum losses in electrical transmission, thus increasing the efficiency with which the stored energy is used."

Jan 1, 1982

The cost benefits of controlling dilution of extracted ore have been very well understood by miners and mining professionals for many years. However, as we strive towards more mechanization, the dilution factor has been compromised in order to fit ?equipment? that is better suited to provide improved safety and productivity. Alternately, the drilling and ground support is accomplished by handheld drilling. In 2007, a short study, commissioned by CAMIRO (Canadian Mining Industry Research Organization) on the safety of hand held drilling vs. mechanized drilling, concluded that the risk of injury with handheld drills was seven times greater than with mechanized drills. Armed with this data, MEDATech Engineering proposed to the CAMIRO group to fund development of a ?MICRO Bolter?.

May 1, 2009

By Sarah R. Hindle

Carbon capture and storage has jumped to the forefront of climate change mitigation efforts for its capacity to sequester large amounts of carbon. Mineral carbonation is one prominent option, mimicking and accelerating the natural weathering process of certain silicate minerals. This has the ability to produce stable carbonate minerals that can store carbon on geologic time scales with little to no risk of leakage. Commercialization of this process is ideally suited for integration into the proposed mining operations at the Turnagain Nickel site in Northern BC. This is due to the abundant supply of suitable ultramafic feedstock material, as well as the economic benefit of sharing costs while reducing net emissions and bringing value to otherwise valueless and costly waste rock. While studies have shown this process to be technologically viable on a laboratory scale, assessing the economic and financial viability of such a process on an industrial scale is necessary. An evaluation of the financial feasibility of integrating mineral carbonation into the mining cycle at Turnagain under a proposed cap-and-trade system is presented.

May 1, 2010

By W. Petruk

A study was undertaken to determine whether interrelations between mineral grains affect ore breakage during grinding, and to establish a correlation between ore breakage and mineral liberation. A base metal ore from the Brunswick No. 12 deposit in New Brunswick was ground for different periods of time in a laboratory ball mill, and both the unbroken ore and the ground products were analysed by image analysis. The results show that the mode of breakage is strongly influenced by the behaviour of pyrite. Similar size distributions were obtained for material from the 15 minute grind in a laboratory ball mill, for the grinding circuit discharge from a commercial mill, and for pyrite grains in the unbroken ore. This similarity indicates that a 15 minute grind breaks poorly bonded pyrite grains along grain boundaries, and represents the limit of easy breakage for the ore. Such a grind liberates both large separate grains of ore minerals and poorly bonded mineral grains that occur in interstices among pyrite. On the other hand the 15 minute grind does not separate moderately bonded mineral grains nor release moderately bonded interstitial minerals from pyrite; a 45 minute grind in a laboratory ball mill is required. It is assumed that, for Brunswick No. 12 ore, a 45 minute grind in a laboratory ball mill is equivalent to regrinding in a commercial mill. Grinding beyond 45 minutes in a laboratory ball mill breaks the ore by fracturing pyrite across grain boundaries and by chipping grain edges. Such intense grinding does not markedly increase sphalerite liberation from Brunswick No. 12 ore, because most of the sphalerite that can be released was liberated at the 45 minute grind. In contrast the intense grinding increases galena liberation because a significant proportion of the galena occurs as minute inclusions in pyrite. These findings show that ore breakage and coincident liberation depend upon size distributions, intergrowths, and mode of occurrence of the minerals in an ore.

Jan 1, 1988

An Attractive Investment ?Near term low cost and secure PGM producer ?restricted supply legislated demand ?strong pipeline of resource development ?Building Canada?s largest undeveloped PGM-Cu resource ?All work (resource, reserves, DFS, EA) is NI43-101 compliant ?Strong balance sheet: over $8 m in cash with no debt

May 1, 2010

By D. E. Salman, R. R. Maclachlan, R. J. Barclay

"There is a considerable resource of data for spherical charge cratering, both as single charges and in row-of-charge geometr(1). The data are. however, based on cratering performance to a single free planar surface.In practice. the more common circumstance involves an angular surf ace geometry. such as occurs at the toe of a bench or the wall of a stope. It is for the purpose of investigating this circumstance that the described test work was conducted.The test objectives were: (1) to observe the change in single-charge cratering performance between planesurface and angle geometry; (2) to identify the optimum performance of single charges cratering to a plane surface. cratering from a bench sub-grade position and cratering from a condition of zero sub-grade or stope wall geometry; and (3) to observe the performance of row-of-charges cratering to an angular surface at various row burials and spacing. The row charge burial and spacing dimensions were to be expressed in simple numerical multiples of single-charge depth-of-burial data."

Jan 1, 1981

Agenda ?Introduction ?Geology ?Mining ?Metallurgy ?Process, Layout ?Environmental Background ?Kinross Gold Corporation owns the Lobo-Marte gold property, located in Region III of northern Chile. ?The property is close to two other Kinross mines, Maricunga 50kmto the south and La Coipa 60km to the north, plus a regional office in Copiapo and district level operating synergies are expected. ?Lobo and Marte were discovered in the early 1980s and are intrusion-hosted, porphyry-type precious metal deposits, typical of the Maricunga District. ?The Marte open pit heap leach mine was in commercial production in late 1988, but was suspended in February 1992 as it did not meet forecasted production levels and recoveries. ?Kinross plans to recover ore from the Lobo and Marte deposits through an open-pit, heap leach47,000tonne per day operation.

May 1, 2010

By B. Surender Mohan

Mother Earth being a treasure of minerals, it is prime duty of the mankind to preserve this natural source to ensure steady growth of the nation. Utmost care is to be taken to see that these natural resources are explored and exploited scientifically in a sustained manner to ensure that the resource base improves and last longer. In this backdrop, the topic of ?Lignite - its resource and technology options to exploit deep seated deposits? is an apt subject to be deliberated upon in the present context, where the shallow deposits may slowly get dwindled. I shall deliberate upon the resource base of lignite, production profiles of the last five decades, consumption pattern, demand / supply projections, future available technology options to exploit the deep seated deposits, growth trends of the sector etc. in my paper. With the available resource base and future technology options, I can confidentially make a statement that ?lignite will remain as cocontributor along with coal to India?s energy generation and may well maintain its same status in the 21st century too, as it has been in the later part of the twentieth century?.

Aug 1, 2013

By Todd Kennedy, Kurt Tischler

"This paper presents the field experience of Siemens with regard to Gearless Drives in the mining industry … We consider the elapsed production hours of Siemens Gearless Drives to be extensive enough to provide a reliable estimation of availability calculated on the basis of data representing repair time, downtime, and operating time. The users of Siemens Gearless Drives confirm an availability of more than 98% after exclusion of some major issues. The paper addresses all of these major issues of Siemens Gearless Drives, describes successfully applied corrective measures, explains the influences on the design of the drives, and lists the downtimes associated with each of these issues. INTRODUCTIONThe first Siemens Gearless Drive in mining began operation in 1980 and was installed on an iron ore grinding mill. As of September 2011, 40 Siemens Gearless Drives will have accumulated 136,000 machine days of operating time. According to pure rules of statistical analysis, this accumulated operating time may be too low to be used for a sample of field data to provide precise statistical values of availability, however we consider it large enough to provide indicative values of worthwhile consideration. This paper deduces the availability statistics of Siemens Gearless Drives in the mining industry from information received from end users and factors in all major issues that Siemens has experienced with our Gearless Mill drives. This paper does not consider Gearless Drives in other industries such as the cement industry. The cement plants, especially in the northern hemisphere, interrupt production for several months in the winter. This lengthy downtime is used to maintain the complete plant including the mills, their motors and their drives. The mining industry has more stringent and higher production requirements. In the mining industry, production must run 24 hours per day, 365 days a year."

Jan 1, 2012

By Li. L.

Backfilling has become a popular solution in underground mines around the world. It reduces environmental impact of mining industry and improves ground stability. In most cases, backfill has a high water content so that it can be delivered by pipes from a backfill plant on ground surface to underground stopes. Upon deposition in the stope, the backfill tends to consolidate under its own weight, leading to a generation of excess pore-water pressure. To avoid excessive pressure and protect the backfill barricade installed at the base of the stope, the backfilling of the stopes is usually divided into two stages: plug pour and backfill body pour. The interruption of backfilling operation is undesirable as it slowdowns the mining productivity, and sometimes causes pipe clogging, leading to unexpected increase in manpower cost and further reduction in mining productivity. The backfilling interruption time may be reduced, even eliminated if the drainage of backfilled stopes is sufficiently improved. This paper presents an application of wick drains, a material commonly used in civil engineering, to mine backfilled stopes to help accelerating the drainage. A protocol is proposed for installing the wick drains in a mine stope to be backfilled. Numerical simulations were made, showing that the drainage of the backfill can significantly be improved by the introduction of wick drains. The application of wick drains in mine backfill can thus be considered as a promising technique and merits deeper and more detailed investigation.

Aug 1, 2013

By P. M. Solozhenkin, O. I. Ibragimova, I. P. Solozhenkin

Molecular models of complexes of poorly studied bismuth, gold, and arsenic mineral clusters and reagents were created for use in collector activity forecasting using Chem Bio 3D and ChemOffice2005, with optimization by MM2. The density functional theory approach was used to determine HOMO, LUMO, SOMO, and total energies, atomic charges, and s, p, d- populations for various compounds. The structure-based virtual screening (SBVS) and docking technique was proposed to reduce the vast number of compounds to a more manageable number for selection of potential flotation candidates. The prognosis of collector activity evaluation (PCAE) strategy was proposed as a consistent approach to estimate the interaction between a collector and a mineral cluster as the difference between the total energy and sum of cluster energy and collector energy to search the analogue of butyl xanthate. The negative relationship between PCAE and flotability was shown. The combinations of dialkylamino sulfhydryl collectors can be considered as prospective reagents for gold-bearing sulfide ore flotation. These results were confirmed by experimental data in ore flotation. The increase in recovery of gold and bismuth with the aid of a combination of reagents has been established and additional cyanidation of tailings has been avoided.

Jan 1, 2016

While this paper is directed towards the ?Bellambie? type of rope attachment, the principles can be applied to any brand of rope fitting however, it is a only a broad outline and the specific installation and maintenance procedures can be obtained from the attachment supplier. The types of attachment to be discussed are:- ?Thimble Type rope cappel ?Wedge Type cappel ?WRC Rope Clamp ? (Rope Glands) ??Hoist and Balance Rope Sockets In each case, the assembly and stripping (disassembly) plus the basic maintenance procedures is briefly described. A guide for Risk Assessment is also included but because of his familiarity with the installation, the end-user is in the best position to draft the final version.

May 1, 2003

By Z. Bibak, S. Banisi, A. Ghasemi, E. Nematollahi

"The use of large AG/SAG mills in the mineral industry has been on the rise recently due to a significant reduction in the capital and operating costs for achieving significant increases in plant throughputs. The major reason for downtimes in these mills is the time taken for the replacement of broken or worn liners. This loss of “availability” of these units has a significant impact on the productivity of these plant operations. The ability to predict liner life time and its evolving shape could help to optimize these comminution operations. In the past decades, various models have been proposed to estimate liner wear rate, but because of their empirical nature they could only be used within certain limited operating conditions. In this research, a phenomenological model which could predict the liner wear rate was proposed and tested. This model considers parameters such as; operating conditions, liner hardness, pressure on the lifter, and, relative velocity of particles and mill shell. Data from industrially measured liner profiles were taken during the liner life time at the Sarcheshmeh and the Gol-E-Ghohar SAG mills to provide a solid base to calibrate and validate the model. The comparison of the model predictions with the actual measurements of the liner wear rate showed that the results were in a good agreement at both, the Sarcheshmeh (R2=0.94), and the Gol-E-Ghohar (R2=0.97) concentrators.INTRODUCTIONAG/SAG mills are one of the most important technologies in the mineral processing industry in the recent decades. The “Availability” of these units in a plant operation is one of the most important economic parameter for evaluating their performance. The major reason for the downtime of these mills affecting their “availability”, is the time required to change worn or broken liners (Yahyaei, Banisi, & Hadizadeh, 2009; Maleki-Moghaddam, Yahyaei, & Banisi, 2012). The knowledge about the magnitude and profile of liner wear not only enables more accurate liner life estimation to prevent unwanted interruptions of the SAG milling in mineral processing plants and more strategically plan the scheduled mill outages for liner changes. It also could provide key information needed to select an appropriate liner design (Yahyaei et al., 2009; Rezaeizadeh, Fooladi, Powell, & Weerasekara, 2010a)."

Jan 1, 2016

By Frank Mucciardi, Louca Gourtsoyannis

"Low and inconsistent recoveries of aluminum in the production of aluminum-killed steels triggered an extensive research program on the aluminum dissolution kinetics at McGill University. This research program led to the understanding of the melting kinetics and the hydrodynamics of making additions to liquid steel. It showed the necessity of gradually releasing liquid aluminum at the bottom of the ladle to increase aluminum recoveries.This knowledge was verified in practice at Sidbec-Dosco, where a prototype aluminum wire injector was developed and installed for the first time in Canada. The industrial application showed the validity of the theoretical and experimental results and provided further data for the mathematical modelling of the process.The development of the theoretical understanding, the industrial results, and the interaction between university and industry are presented.IntroductionAluminum is an extremely effective deoxidizer of molten steel; nevertheless, an efficient method of adding it to steel has eluded steelmakers for many years. It is well known that the recovery of aluminum used in the production of aluminum killed steel is both low and eratic, especially when the aluminum is added in the form of bars or lumps from chutes into filling ladles, a practice still common in many of today's steelmaking operations.As the density of aluminum is only about 40010 that of molten steel, it is conceivable that loose bars of aluminum simply ""thrown"" into a filling ladle will resurface before any appreciable dissolution of the aluminum has occurred, particularly if the depth of penetration of the additions is small. Before one can conclude that this is indeed the case, it is necessary to know the melting kinetics of an aluminum addition. Back in 1972, this information was not available; hence an extensive research program which focused on melting kinetics was initiated at McGill University."

Jan 1, 1982