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By D. DeGagne, E. De Souza, J. F. Archibald

This paper describes the potential use of anew agent material for backfill consolidation, ground waste glass, to be used as partial replacement of Portland cement fractions within backfill. Significant fractions of commercial and residential silica glass production is currently utilized as waste landfill and must be disposed of at high cost and with no foreseeable environ-mental benefit. This paper also demonstrates that waste glass materials could be effectively recycled as backfill additives, and that a significant, large and stable source of additive supply, currently land filled, can be developed. This new application will generate added value for such materials, serve to promote positive environ-mental stewardship and satisfy engineering sup-port requirements in mines.

Jan 1, 1997

By J. E. Hawley

Introduction The Siscoe gold mine is the most easterly producer of gold from deposits lying in the belt of Keewatin and Timiskaniing rocks which extends east from Kirkland Lake, Ontario, and on through the Rouyn copper area. Unlike many of the deposits in this belt, those of Siscoe are contained almost entirely in a stock of much-altered granodiorite which intrudes Keewatin lavas. They are situated on an island of about one square mile in area, lying in lake De Montigny, Dubuisson township, 40 miles south of Amos, on the Transcontinental branch of the Canadian National railways, and 52 miles east, and slightly south, of Noranda. Geographically, the deposits are favour-ably situated with respect to transportation facilities, a through water-route being available from Amos, along the Harricana river and its lake expansions. The deposits consist of auriferous quartz-tourmaline veins of the fissure-filled type and are of particular interest because of their geological structure and genesis. Furthermore, deposits of a similar type occur both in the Keewatin and in granodiorite bodies to the east, in Dubuisson, Bourlamaque, Pascalis, and Louvicourt townships, and it is hoped that the following discussion may be of some aid in the exploration work now being carried on throughout this general area.

Jan 1, 1932

By Louis J. Cabri, Donald Hoy

"Samples with contrasting gold mineralization were studied quantitatively prior to metallurgical tests. The AD samples are coarser-grained and characterized by abundant Sb minerals (jamesonite, berthierite, stibnite). The finer-grained MW sample has abundant pyrite and pyrrhotite, with arsenopyrite and galena next in abundance. A large number of gold mineral particles were determined by SEM investigation of hydroseparation concentrates, ranging from 150 to 597 per sample. The grain-size distribution of the gold minerals shows evidence of bimodal grain-size distributions (volume %), with the coarse fraction being most significant in sample MW-1 (maximum ECD=308µm). The coarsest gold minerals in the AD samples range from 139µm to 281µm ECD.The deportment of gold minerals is as electrum, aurostibite, native gold, and a possible new mineral (AuNiSb4). Gold also occurs in nisbite. The gold minerals are dominated by electrum in three samples and aurostibite is next in abundance. The major gold minerals are probably representative of three stages of gold mineralization. The first stage is represented by electrum, which is partly to completely replaced by Sb-rich mineralization forming aurostibite, and the last stage is native gold, often occurring as rims on one or the other earlier gold mineral. The gold minerals are strongly associated with sulphides in the AD samples (55 to 60 vol.%). At the grind used for the hydroseparation the liberated gold mineral quantity (volume %) is also significant, ranging from 65% for sample MW-1 to 30 to 37% for the AD samples.INTRODUCTIONThe Clarence Stream deposit is located 70 km south-southwest of Fredericton and 25 km northnorthwest of St. George, south-western New Brunswick, near the international boundary with Maine (Fig. 1)."

Jan 1, 2007

By Bill Almdal

Today?s presentation ? Role of the Regional Issues Working Group ? What does RIWG do? ? How can RIWG?s work benefit Stakeholders? ? Review of forecasts vs. reality ? How have past investment compared to the reality? ? Risks to future growth ? The growth potential is very high and so are the risks ? Examples of outputs ? Housing needs ? Growth in population ? Tires for large trucks The Regional Issues Working Group ? Our vision ? To provide a proactive process which promotes the responsible, sustainable development of resources within the Regional Municipality of Wood Buffalo for the benefit of all stakeholders ? What we do ? Facilitate planning for growth ? Facilitate effective and efficient resolution of issues ? Involve all of the resource developers and affected stakeholders in planning ? Develop plans for sharing benefits with Aboriginal stakeholders ? Benefits for Stakeholders ? Our forecasts include up-to-date information from all developers ? including information on employment and housing needs ? Our forecasts are the basis of planning for many stakeholders ? and can assist in their development planning

May 1, 2002

By S. McAlister

"Falcon Concentrators Inc. has developed a high capacity centrifuge for the recovery of fine, free gold as well as other metals and minerals which were previously thought to be unrecoverable by gravity means. Development started in the early 1980's and the first commercial operation was commissioned in 1986. Gold applications include scavenging conventional gravity and cyanidation circuit tailings, cleaning gravity concentrates, cleaning flotation concentrates to melting grade, scavenging flotation tailings, and placer mining. Recent development work by Falcon has expanded the applications scope of the centrifugal concentrator to include many minerals amenable to gravity concentration including iron, tin, industrial minerals, and hazardous wastes. This paper discusses this technology including its history, present applications, and future potential. OVERVIEW OF CENTRIFIJGAL CONCENTRATIONUsing centrifugal force to enhance the separation of materials by differential specific gravity has been researched for over a century. Many attempts have been made to concentrate minerals in high gravity fields. Patents were granted on this subject as early as 1891 (see Figure 1). Patenting activity continued into the 1920's and has been relatively quiet since. It is significant that no centrifugal system of gravity concentration has been broadly accepted by the mineral processing community until recently. Much of the world's reserve of mineral deposits which are amenable to conventional gravity concentration technology (coarse-grained) have been mined and therefore there is an increasing demand for technology which can economically recover the fine-grained gravity recoverable minerals in the remaining deposits. In addition, centrifugal concentration can play an increasing role in solving environmental problems by offering an inexpensive method of concentrating hazardous materials such as uranium, plutonium, mercury, lead, and other heavy metals. The overall cost of disposing of these substances safely can be drastically reduced if they are recovered into a concentrated form prior to disposal."

Jan 1, 1992

By J. P. Harrison, N. Bozorgzadeh, M. Dolowy-Busch

"It is common in rock engineering practice to characterize the triaxial strength of intact rock by using only data samples of small size. Practical guidelines such as ASTM support such sample sizes. In this paper, we investigate the reliability of the Hoek-Brown strength criterion estimated from such samples. For this purpose, we use an unusually large published set of triaxial strength data to randomly select a large number of data samples of small size to simulate the situation that frequently encounters in practice. The samples are generated with different arrangements with regards to the confining pressure. We fit the Hoek-Brown criterion to each of these samples, obtain estimates of strength parameters and compare them to those obtained from the complete data set. Our analysis suggests that estimates based on small samples are not reliable and can lead to both over- and under-estimation of strength.Additionally, we use these small samples to investigate the statistical methods for obtaining design values of strength as suggested by limit state design standards such as Eurocode 7. We show that, if used in conjunction with small samples, these methods do not guarantee a safe estimate of strength and in many cases lead to highly over-conservative estimates.We present a potential solution to this problem by augmenting the small data sets with Bayesian informative priors to give much more reliable estimates of strength. We conclude with suggestions for the development of informative prior distributions."

Jan 1, 2015

By O. K. Mahabadi, A. Lisjak, B. S. A. Tatone, N. Vlachopoulos

"Numerical simulations are widely adopted in the design of several types of rock structures, including tunnels, caverns, rock cuts, and open pit and underground mines. In recent years, analyses based on the hybrid finite-discrete element method (FDEM) have been shown to provide a realistic representation of rock mass deformation and fracturing processes. To date, the FDEM approach has successfully yielded qualitative and quantitative results for several practical rock engineering applications, yet it has lacked the ability to consider the implementation of rock-reinforcement measures. Since rock reinforcement is often used in civil and mining applications to improve the strength and deformational behaviour of a rock mass, the ability to incorporate such features into FDEM analyses is essential to extend its applicability to a broader range of problems. The work presented in this paper represents an important first step towards developing a simulation tool that can be used for practical rock engineering applications, including the design of underground excavations and rock slopes.INTRODUCTIONRock support and reinforcement measures are often employed in civil and mining rock engineering projects in order to maintain or improve the strength and deformational behaviour of rock masses. The preferred type of reinforcement or support elements along with the preferred layout and timing of installation depend on the in-situ ground conditions, the nature of the rock mass and excavation method. Over the last two decades, numerical modelling has been increasingly used to design and attempt to optimize rock reinforcement and support systems. As such, most rock engineering-specific modelling software now offers various approaches for modelling different rock reinforcement and support elements."

Jan 1, 2015

By J. L. Jambor, E. J. Reardon, E. C. Appleyard, J. A. Cherry

Abstract- Since the 1957 initiation of deposition of mill tailings at the Heath Steele mine, New Brunswick, periodic detailed studies of the tailings geochemistry and mineralogy have been con­ ducted, thereby providing a unique opportunity to examine the geochernical evolution of a sulfide- rich mine-tailings impoundment. When deposited, the tailings contained about 85 wt% sulfide minerals, 1 wt% to 3 wt% carbonate minerals, and 12 wt% to 14 wt% aluminosilicate minerals. Mineralogical examination of samples of the tailings from deep in the impoundment indicates that little oxidation occurred prior to tailings deposition. The mill process-water deposited with the tailings was neutral to slightly basic and contained low concentrations of Cu, Pb, Zn and As. Sampling of the tailings five years after deposition indicated that sulfide-oxidation reactions, occurring near the tailings surface, had decreased the tailings-water pH and increased the concentrations of Fe, SOi-, Cu, Zn and Pb (up to 10 000 mg/L, 25 000 mg/L, 2.5 mg/L, 200 mg/L, and 4.5 mg/L, respectively) . In 1975, ten years after decommissioning, the tailings could be divided into three zones: an upper oxidation zone in which sulfide oxidation is actively occurring, a hardpan layer, 15 cm to 20 cm thick, composed of tailings cemented by secondary Fe minerals, and an underlying reduction zone in which the tailings are relatively tinoxidized (Boorman and Watson, 1976). Chemical analyses indicated the presence of low-pH waters containing very high concentrations of SO42- , Fe, and other metals (up to 63 600 mg/L SO42-, 28 600 mg/L Fe, 10 mg/L Pb, 600 mg/L Cu and 4000 mg/L Zn), suggesting that there was a period of intense sulfide oxidation between five and ten years after tailings deposition. More recent sampling, conducted some 20 years after the end of tailings deposition, indicates that relatively little change has occurred in the last ten years, thereby suggesting that the hardpan layer has provided an impediment to the downward movement of dissolved constituents . Analyses of the tailings solids show increased accumulations of many metals at or near the depth of the hardpan layer. Evaluations of the long-term evolution of the tailings can be enhanced by comparison of descriptions of the tailings with descriptions of the gossan that overlay the massive­ sulfide orebody prior to mining. At Heath Steele, this comparison suggests that many of the mechanisms controlling the distribution of metals in the tailings will probably persist over geologic time.

Jan 1, 1992

By J. S. Godard

The mining developments in western Quebec have shown the ores of this district to be more complex in character than was at first expected. When the initial discoveries were made it was thought that the ores would be similar in character to those of Kirkland Lake and Porcupine areas. Developments have since shown that although the ores along the southern margin of the belt are somewhat similar, those within the belt, constituting by far the greater proportion, are vastly different, being complex mixtures of base-metal sulphides carrying values in the precious metals. These mixtures of base-metal sulphides of copper, zinc, and iron, present several problems to the metallurgist, especially in their concentration into marketable products. For the purpose .of this paper the following classification may be made of the ores of the district. Group I. - Milling Ores: (a) Ores in which~ arsenopyrite is the predominating sulphide. In this class of ore the gold occurs in fractures in the quartz and is associated to a lesser extent with the arsenopyrite and pyrite. Examples of this class of ore are the Granada, south of Pelletier lake, and the O'Brien and the Thompson in Cadillac township. (b) Ores in which iron pyrite is the predominating sulphide and gold is the valuable constituent. This may also be classed as a concentrating ore-Group III.

Jan 1, 1928

By M. J. Beus

Many mines in Canada, the United States and South Africa are reaching the hoisting limit. Very little payload will be possible without compromising safety due to the excessive weight. It has been suggested (DeLorme, 2000) that one of the most attractive concepts to enable deeper hoisting is to reduce the allowable factor of safety in the wire rope. Researchers at the Spokane Research Lab are developing new technology to improve hoisting safety and productivity by providing new monitoring and analytical tools. A Shaft Conveyance Monitoring System (SCMS) has been developed which determines hoist rope end load, true conveyance position and acceleration, and rope safety factor, as well as other hoist operating parameters. This information is transmitted to the hoist operator display 20 times per second. Recent field measurements on 45 mm (13/4 in.) diameter hoist rope indicate that dynamic forces during loading of a 9000 kg (10 ton) skip could exceed the safety factor of the rope. To improve on the current understanding of the mechanical behaviour of hoist ropes, and to help interpret the results from field-testing of the SCMS, a new approach to computer modelling of stranded wire rope is also being developed. Particle Flow Code, PFC3D (Itasca, 1999), is used to simulate the structural behaviour of wire rope and the interaction between individual strands when the rope is subjected to static and dynamic end loading. Details of the SCMS, field results from the measured rope loads, and the results of numerical modelling on the wire rope will be discussed.

Jan 1, 2002

By V. I. Lakshmanan

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

Jan 1, 2011

By G. E. Rowan

"DURING the dark ages, the cherished dream of chemists was to find a process for converting base metal into gold. Many a wealthy-but-gullible patron lost a fortune in the search. Men who work with metals today are a bit more realistic. I haven't heard of a metallurgist who expects to develop any one alloy that will resist all corrosive media. In the field of stain-less steels, there are about forty different types of alloys that are used where corrosion is a •problem.A stainless product is ordinarily selected because it offers one or more of the following qualities:(1) Resistance to corrosion (2) Resistance to oxidation at high temperatures (3) Good mechanical properties at room temperature (4) Good mechanical properties at high or low temperature (5) Attractive appearance (6) Ease of maintenanceToday we are interested in discussing the stainless steel family of alloys because of their .ability to resist corrosion. We• will not try to explain the Theory of Corrosion. Let us assume that, when surface potential and oxide formations are properly controlled, iron will resist attack in various chemi.cal solutions. The addition of alloying elements to iron does this for stainless steels. The principal stainless alloys used by various Canadian industries are listed in the accompanying Table."

Jan 1, 1959

By Grant Small, Jessica Kinal, Christopher J. Greet

"The conversion from an electrochemically reactive grinding media (forged steel) to a more electrochemically inert alloy (high chrome white iron) not only reduces the wear rate of the grinding media, but also has an impact on the grinding chemistry. Typically the grinding chemistry becomes more oxidising, with less reducing Eh values and more dissolved oxygen in the pulp. There is also a decrease in the EDTA extractable iron, which is an indication of the change in the media corrosion. These changes are indicative of alterations in the surface chemistry of the minerals that the operator is trying to separate. For porphyry copper ores the changes in the pulp and surface chemistry not only affect the copper sulphide minerals, but also impact the iron sulphides (i.e. pyrite and pyrrhotite). Generally, with more oxidising pulp chemical conditions during grinding there is an increase in the oxidation of the iron sulphides which renders their surfaces hydrophilic, thereby depressing flotation. This leads to improved selectivity for copper sulphides against iron sulphides.INTRODUCTIONPorphyry copper deposits are the dominant source of copper that is mined today to satisfy global demand. These style of deposits typically contain one percent copper mostly as chalcopyrite, but may contain other copper bearing minerals (for example, bornite, chalcocite, azurite, malachite), small quantities of pyrite and quartz. Porphyry copper deposits also contain economically significant quantities of gold, silver and molybdenum. Interestingly, the majority of the world’s porphyry copper deposits are concentrated along tectonic plate boundaries (Figure 1)."

Jan 1, 2016

On the 26th of June 2000 a hydraulic fill retaining barricade failed at the Bronzewing mine in Western Australia. The barricade failure resulted in the release of 19,000 m3 of saturated hydraulic fill into the mine and caused the deaths of three miners. Following this tragic accident, the practices and procedures of mines using hydraulic fills came under intense scrutiny by regulatory bodies and mining companies. At this time, the use of hydraulic fill at Normandy?s zinc/copper Scuddles mine was suspended and waste rock became the sole backfill material in use underground. By 2003, development of the adjacent Gossan Hill mine had progressed to a point where a self supporting fill material was required to enable full recovery of high grade ore. Cemented hydraulic fill (CHF) was identified as the optimal fill type and work began on designing appropriate management procedures and controls to ensure the safe implementation. This work included definition of the fill properties, plant design and construction, reticulation system design, design of stope barricades and drainage systems and fill placement control and monitoring practices. CHF placement began on 16th July 2004 and has continued to date. Significant operational experience has since been gained in areas including plant performance, fill product quality assurance, barricade construction, stope drainage and in-situ performance.

May 1, 2007

By J. P. Cooney

Placer Dome is learning from experience in Latin America, Asia and Africa, as well as in North America, that contributing effectively to sustainable human progress in the areas of its operations presents unending challenges to think creatively, communicate effectively and remain culturally sensitive. People must be better off in terms of their economic circumstances, their social conditions and the quality of their natural environment not only during the life of the mines, but after mines close. Stakeholders, all those who are directly or indirectly affected by a mining project, should be able to participate in decisions which affect them. The development of sustainability strategies, the monitoring of sustainability performance and the implementation of sustainability programs are best done in partnerships with governments, communities, nongovernmental organizations and multilateral development institutions. Ultimately, the success, if not the survival of mining, will depend on our ability to get the sustainability equation correct.

Jan 1, 2000

By T. R. Wildeman

"At the Big Five wetland, which was built to treat drainage from a metal mine, encouraging results have attributed to sulfate reduction. Cu and Zn were reduced to below detection limits of 0.50 mg/L, Fe was reduced by at least 90% to below 3 mg/L, and the pH was raised from below 3 to above 6. The study showed that treatment was primarily through microbial processes within the substrate and that plants were not needed to insure success.Constructed wetlands can be taken through design and proofing stages, and into operations scale in a meaningful time frame for on-line acid drainage remediation. In staged design, laboratory experiments are initiated to determine reasonable substrate materials for remediation of a particular drainage. When a reasonable substrate is found, bench scale experiments are initiated as the next stage in the design. In these studies, removal efficiency, permeability, and flow are analyzed to identify candidate substrate which will support sulfate reduction and be hydraulically reasonable. Using this design method at one site, an acid drainage of pH 2.5 was raised to a pH of above 7. Total heavy metal concentrations in this drainage exceeded 900 mg/L. In the pilot constructed wetland Cu, Zn, and Fe were reduced by 99%.Determining how well these anaerobic cells operate in the winter is done at the pilot plant site in Idaho Springs, CO. It's been found that over the last four winters, those cells that emphasize anaerobic removal within the substrate have operated continuously and effectively the year round. Winter operation is aided by the fact that the water temperature of the acid drainage is always between 14 and 16° C, and the cell can be readily insulated from the cold. Activity of the sulfate reducing bacteria may decrease during the winter. However, it appears that organic complexation of metals helps to maintain low concentrations of metals in the effluent."

Jan 1, 1992

The #3 Shaft at Brunswick Mine, Bathurst, New Brunswick, Canada, intersects a soft graphite zone just below the 3400 Level. Ground movement within this zone causes the concrete liner of the shaft to be deflected towards the shaft?s interior, affecting the steel framework of the conveyance. In some areas, the clearance between the cage and the liner has been reduced to less than 2 cm, which is a concern. An innovative surface-mounted extensometer was designed in 2008 to monitor potential movements of the shaft?s liner. Four such novel extensometers were installed in the shaft for the surveillance of a particularly critical 3.0m by 5.5m area. This article describes the approach taken to instrument the shaft, the principle of the new extensometer, as well as the performance of the instrumentation following its installation.

May 1, 2009

By Peter Waggitt

Northern Australia has been home to uranium mining for over 70 years, more or less continuously. In the early days, post World War 2, there was little effort made to remediate workings at the end of operations. The three “campaigns” of uranium mining (1951-55; 1960-70; and 1979-present) are all now in various stages of remediation. This includes not only the large legacy site at Rum Jungle but also smaller fields like the South Alligator Valley, as well as contemporary works at Nabarlek and the ongoing closure at Ranger– Australia’s longest operating uranium mine. This paper briefly describes some of the past remediation activities before providing an update on the Ranger closure programme and future timetable.

Jan 1, 2020

By Dr. O. M Solandt

CANADA is not an old country we are just now planning to celebrate our lOOth Anniversary. Nonetheless, we have already developed some well-established traditions. One of the minor traditions is the standard speech on the need for more research and development in Canadian industry. I am sure that you have all listened to it many times -I certainly have given it more than once. Much as I am tempted to honour this tradition by repetition, I shall only give you a thumbnail sketch of the ancient address for the benefit of any unfortunate visitors who have not heard it before, and also to provide a base for some further ideas that I want to leave with you. Briefly, the traditional story is that, for a variety of historical and environmental reasons that I shall not attempt to describe in detail, research and development in Canada has grown up in a pattern that is ill adapted to foster the expansion of our manufacturing industries. The story continues by saying that research in the universities is of excellent quality but that we are very short of money to meet the expanding needs

Jan 1, 1965

By K. A. Mackinnon

The choice of fan type (axial flow, centrifugal or mixed flow) most suited for a mine ventilation application depends on a number of technical and economic factors. For each project, the relative importance of these factors will vary. It is worthwhile to carry out an assessment on a case by case basis. The paper, by discussing a number of technical and economic factors and their interactions, will provide the ventilation official a methodology to easily and methodically undertake such an assessment.

Aug 1, 2013