Search Documents

By J. S. Roberts

"Campbell mines has been in operation since 1948. Part of the process consists of roasting of a flotation concentrate which contains arsenopyrite.At present operation level the milling rate averages about 850 t.p.d. and about 48 t.p.d. of concentrate is roasted. The gas emissions at present contain between 3 and 3.5 t.p.d. of arsenic trioxide, about2 - 2.5 t.p.d. of particulate matter and between 19 - 25 t.p.d. of sulphur dioxide. The particulate is extremely fine calcine dust and it assays about 4 oz. Of gold per ton.Until 1974 the gas was discharged untreated through a 125' stack.UntreatedThe decision was made in 1972 to erect a gas treatment plant, construction ran through 1973 and operation began in 1974. The cost of the installation was about 1.3 million dollars.On investigation the process technology, it was apparent that the plant operated by giant Yellowknife for the same purpose was the model we should study. I would like to acknowledge the fine cooperation we had from giant, the plant that emerged is very similar to theirs and incorporates some improvements suggested by them and based on their operating experience.The plant is designed to remove arsenic and solid dust and it has no provisions to remove sulphur dioxide.We depend upon the 125' stack to assure adequate dilution. Because of the nearby airport the stack cannot exceed 125'. A stack burner is provided that can ""y used to heat the stack gas and carry it higher into the atmosphere when there is an inversion condition.The removal of arsenic from hot gas is fairly simple. The sublimation point is about 425°f, a few degrees above this point the arsenic is a gas and a few degrees below it condenses into a solid form. The arsenic could have been removed by simply dropping the temperature below the condensation point and collecting all the solids in a baghouse. This would have removed the possibility of recovering the gold in the calcine dust and would have produced an impure and more bulky arsenic material to be placed in safe storage. The decision was made to collect the solid dust in a hot electrostatic precipitator operating above the sublimation point and subsequently lower the temperature below the condensation point and collect the arsenic in a baghouse."

Jan 1, 1976

By Renato Macciotta

The argillaceous formation known as the Opalinus Clay is host to the Mont Terri Underground Research Laboratory. The URL was developed to investigate the hydrogeological, geochemical and geotechnical properties of the formation. Underground excavations at the site are characterized by non-elastic and time-dependent deformations. Excavations trending perpendicular to the strike of the bedding presented relatively minor deformations, however, tunnels parallel to the strike of the bedding showed much larger non-elastic deformations. This paper presents an analysis of the measured response of a tunnel trending parallel to the strike of the bedding in Opalinus Clay. The measured convergence is compared to tunnel experience in weak rocks to assess the tunnel stability.

Jun 1, 2012

By Phil Keele

"Manalta Coal Ltd. 's Vesta Mine will supply Alberta Power Limited's 740 MW Battle River Generating Station with 1 128 000 tonnes of sub-bituminous ""C"" coal in 1983. Mana/ta Coal Ltd. and Alberta Power Limited are in their seventh year of a 31-year coal supply agreement. With the exception of localized topographic highs where three coal seams are mined, the Vesta Mine is primarily a single-seam mining operation. Vesta's comprehensive programs of mine planning, preventative maintenance, reclamation, and employee relations make it an efficient and a well run operation. Introduction The Vesta Mine, located in east-central Alberta approximately 300 km northeast of Calgary, supplies sub-bituminous ""C"" coal to Alberta Power Limited's 740 MW Battle River Generating Station. The coal reserves and principal stripping equipment are owned by Alberta Power Limited. Manalta Coal Ltd. owns and operates the additional mining equipment and support facilities. Coal production is from a single pit, 3.5 km in length. Both single and multi-seam operations are encountered in the active pit. In 1983, production is anticipated to increase to I 128 000 tonnes from 906 000 tonnes in 1982. The additional tonnage will be achieved by operating 24 hours per day, 5 days per week. The following sections briefly highlight historical, geological and mining/reclamation aspects of the Vesta Mine. Figure I illustrates the location of the Vesta Mine in relation to the cities of Calgary and Edmonton. History Coal mining for domestic use began near the turn of the century in the Vesta Mine area. Initially, small underground room-and-pillar operations were dominant. As equipment technology advanced, surface strip mining replaced the underground methods."

Jan 1, 1985

By E. Mataradze

Statistics shows that the majority of accidents with fatal outcome are caused by methane and/or coal dust explosion. This leads to assume that contemporary counter-explosion systems of various designs cannot be considered effective. Considering the growing threat of methane explosion in the coming years along with the development of deeper levels, the improvement of a system for protecting people in underground opening appears urgent. This paper presents the results of the testing of the Automatic System from Methane Explosion in Coal Mines. The protective system consists of: i) a wireless device for the detection of explosions and activation of a protective system, and ii) an absorber with a pyrotechnic device ensuring the discharge of dispersed water. The protective system, at the command of the initiation signal, produces tailored dispersing water mist with droplet sizes in the range of 25?400 ?m along selected tunnel sections.

Aug 1, 2013

By Peter K. Kaiser

Planning and design of deep underground mines involves a process of complex three-dimensional data integration utilizing information from exploration (geology, rock mass characteristics), engineering (mining method, excavation geometry, stress) and operations (time, in the form of sequencing). As new logging and monitoring technologies are being developed, the amount and data complexity becomes overwhelming and decisions are often made based on only a small part of the available data. Recently, Laurentian University opened a state-of-the-art Virtual Reality Laboratory (VRL), a Mining Exploratorium that is unique in the world of mining and offers an exceptional data interpretation environment for mine planning and design. The Mining Exploratorium combines a large format spherical stereoscopic projection system, equipped with high definition projection providing the highest resolution of active stereo in the world today, with advanced features of earth modeling software. Combined, this creates the first virtual reality facility geared specifically to the interpretation of mine geometry, geology, geochemistry, microseismicity, geomechanics and mining data sets. This paper demonstrates how value can be added to the mine planning and design process by utilizing this unique tool in the mining decision-making process via better comprehension of spatial relationships of data and by interpreting the data in a collaborative immersive virtual reality environment.

May 1, 2002

By L. M. Dwarkin

Introduction Avital factor in the success of any coal mining operation is the method of roof support employed. A coal seam in? place has been described as the filling in a geological sandwich and the process of mining as the art of snatching the filling from the midst of the sandwich. The difficulty of this task can be appreciated -in the realization of the tremendous weight bearing on a coal seam due to overlying strata; a weight that can exert pressures of several thousand pounds per square inch. Over the years that mining has been carried on, methods have been evolved by arduous trial and error, making possible the successful extraction of billions of tons of coal. However, these time-proven methods are not enough. The constant demand for faster and cheaper production, the necessity of mining under increasingly difficult conditions, and the requirement for higher standards of safety, call for ever better and more efficient roof support. A recent and very promising development in answer to this need is that of Roof Bolting. Roof Support in General Before proceeding to the subject proper, a brief discussion of the older roof support methods is of value in illuminating the difficulties involved and the problems to be solved.

Jan 1, 1951

By C. H. Sleeman

"The Iron Ore Company of Canada constructed a beneficiation complex in Sept-Iles, Quebec, to concentrate and pelletize earthy red hematite iron ores from the Knob Lake area. The plants were scheduled for initial production during the first quarter of 1973.Many problems have been experienced to date. Difficulties in controlling the process, excessive mechanical failures, design deficiencies and manpower-staffing problems have caused an extended start-up. The problems are now essentially solved and, with the completion of some additional minor modifications, it is expected that the plants will be producing premium iron ore pellets at or near rated capacity within the next immediate period."

Jan 1, 1976

By C. T. Harper, B. J. Fryer, R. P. Taylor

"IntroductionThe Maurice Bay deposit is one of a number of uranium deposits that have been found in recent years in the Athabasca Basin of northern Saskatchewan (Tremblay, 1982). This deposit, along with the others, belongs to the unconformity type deposits (Beck, 1977). They are, for the most part, polymetallic, being characterized by a suite of metals which include U, Ni, Co, Cu, Pb, Zn, Mn, V, Ag, Au, Pt-group elements, S, As, Bi, Se, Te, and Mo, some of which, besides U, are present in economic concentrations (Amok, 1974; Ruzicka, 1975; Tapaninen, 1976; Hoeve and Sibbald, 1978; Dahlkamp, 1978). The Maurice Bay deposit was known to be a small low grade deposit in which the ore was essentially monomineralic, consisting mainly of pitchblende (Harper, 1978). However, the occurrence of trace amounts of some of the elements common in the larger polymetallic ore bodies (e.g. Key Lake, Cluff Lake D) was anticipated. Thus a lithogeochemical sampling project was undertaken in 1979 across part of the Maurice Bay deposit (Harper, 1979). Major oxides (SiO2, Al2O3, FeO, Fe2O, MgO, CaO, K2O, Na2O, MnO, P2O5, and TiO2) and a group of the most common trace metals (U, Ni, Co, Cu, Pb, As, Au, V, and Se) were analyzed to determine whether any elemental patterns (halos or depletions) could be detected which would reduce the number of pathfinder elements needed for exploration purposes. In addition to the above metals, Th was also checked because some conglomerate strata in the Maurice Bay area are known to be thorium-enriched (Harper, 1978). Only the trace metal distributions will be discussed in detail in this report.General GeologyThe Maurice Bay area is underlain by three major groups of rocks, the White Lake metamorphic complex, an unnamed granodiorite complex, and the Athabasca Group, described previously (Fig. 1; Harper, 1979). Table 1 summarizes the stratigraphic features as deduced by geological mapping and the examination of drill cores."

Jan 1, 1986

By Bernard Dallaire, Jean Cayouette, Sylvain Duchesne

"Louvicourt Mine's concentrator, located near Val d'Or, Quebec, treats an average of 4,300 tonnes of ore per day composed mainly of copper, zinc, gold and silver. An analysis of concentrator revenues and metallurgical losses shows a potential for additional gain, particularly in regards to precious metals (kustelite) where recovery is usually around 67 -70 %. The planning, installation and trial operational period of two Outokumpu SK-240 flash cells at the underflow of the primary cyclones took two years. The use of (( flash flotation )) technology has made it possible to exploit the favourable conditions at the underflow of the primary cyclones such as precious metal concentration and the presence of liberated coarse chalcopyrite. These conditions permit early flotation (fresh surfaces) of the kustelite and the liberated copper. Since the start-up of the flash cells, the metallurgical gains have turned out to be very positive with increases in metal recovery reflected in appreciable NSR gains. Also, significant savings in reagent consumption and a coarser copper concentrate have made it possible to reduce the drying cycle of the Larox filter presses since the cells were put into operation.BACKGROUNDLouvicourt Mine is operated by Aur Resources Inc. (30% ownership) on behalf of its partners Novicourt Inc. (45%, subsidiary of Noranda Inc.) and Teck Corp. (25%). The mine is located in northwestern Quebec about 600 km north of Montreal and about 25 km east of the mining town of Val d'Or. The mine commenced commercial production in July 1994.The massive sulphide ore deposit lies at depths varying between 450 m and 900 m. Mining reserves (2% Cu equi. cut-off) as of Jan. Is', 2000 are estimated at 7.5 million tonnes of ore averaging 3.4% Cu, 1.8% Zn, 28.0 g/t Ag and 0.9 g/t Au. Delineated ore reserves permit the use of a mechanized transverse blasthole mining method. The extraction order is a typical 1.3.5 mining sequence. Primary and secondary stopes are 15 m wide, 15 to 70 m long (25 m long average) and 30 m high. Backfilling for pillar recovery and regional stability is required."

Jan 1, 2001

"The first SkimAir flash flotation cell was installed in Outokumpu’s Hammaslahti Copper Concentrator in 1982 to prevent overgrinding of soft sulphides in the milling circuit. Since this first installation the popularity of the flash flotation has fluctuated depending on metal market conditions and regional preferences. Units have been installed in many commodities including copper, lead, gold, PGMs, silver and nickel. Though it has been successfully employed in many operations around the world, flash flotation technology is still not well understood by many in the mining industry. This paper will discuss aspects of flash flotation flowsheet development along with some of the metallurgical and engineering considerations required to successfully incorporate flash flotation into new or existing milling circuits. This paper will also try and debunk some of the myths that exist around flash flotation cells and their operation. Case studies of flash flotation implementation will be discussed.IntroductionModern flash flotation technology was developed several decades ago by Outokumpu, with the first commercial installation of this technology being at the Hammaslahti concentrator in Finland in 1982 (Kallioinen & Niitti, 1985). This was a relatively modestly sized SK80 cell producing final grade copper concentrate directly from the flash flotation cell operating in the grinding circuit. Since that time the size and number of flash flotation cells installed globally has grown considerably to the point where today, it is a widely known application of flotation technology for amenable ores. Owing to their long history in developing the technology, Outotec are the market leader with their SkimAir range of flash flotation cells. Though there is a general awareness of flash flotation process in the mineral processing industry, there is a lack of detailed understanding of the process and the benefits it can provide to new and existing operations."

Jan 1, 2017

By N. C. Carter, Wm. H. White, J. E. Harakal

"Of twenty-one ore deposits in British Columbia which are either in production or advanced stages of exploration, five have potassium-argon ages in a range of 165-205 m.y., eight are in a range of 44-55 m.y. and the remainder are either ca. 140 m.y. or ca. 100 m.y. old. Deposits of the oldest group have generally similar geological environments and radiometrically indistinguishable ages of magmatic and hydrothermal minerals. Deposits of the youngest group also have similar geological environments, with successive magmatic and hydrothermal events closely intermingled in time and place. Such deposits find no comfortable home in existing classifications of ore deposits. 1t is suggested, therefore, that those epigenetic deposits which can be shown by radiometrie and/or geologie means to be coeval with genetically related magmatism be designated as ""paramagmatic deposits."""

Jan 1, 1968

By H. Son

The three-dimensional (3D) reconstruction of as-built industrial plant models plays an important role in revamping planning, maintenance planning, and preparation for dismantling during the lifecycle of industrial plants. Recently, the 3D reconstruction of existing industrial plants was conducted using laserscan data to make surveying processes more efficient. However, the current 3D reconstruction process from laser-scan data is still limited due to the need for significant human assistance. Although a great deal of effort has been made to efficiently reconstruct 3D as-built industrial plant models, the presence of objects?such as equipment, pipelines, and valves of different sizes and shapes?in existing industrial plants significantly increases the complexity of laser-scan data and makes automating the reconstruction process more challenging in practice. The purpose of this study is to propose a knowledge-based approach for the 3D reconstruction of as-built industrial plant models from unstructured laser-scan data. First, pipelines were extracted from laser-scan data based on surface curvature information and knowledge about pipelines' sizes from existing piping and instrumentation diagrams (P&ID). Once entire pipelines were extracted, they were modeled based on skeleton features. Then, the remaining objects were clustered and grouped separately via the region grouping process. Afterward, clustered objects were retrieved and modeled based on global feature-based matching from the 3D database. Finally, the resulting model was checked to ensure that it was well-reconstructed according to the information regarding the relationships among objects abstracted from the existing P&ID. The preliminary results on actual industrial plants show that integrating knowledge into the reconstruction steps played an important role in the proposed approach and that this approach obtained accurate as-built industrial plant models from unstructured laser-scan data. The proposed approach could be successfully utilized to assist in many applications during the lifecycle of industrial plants.

Aug 1, 2013

By V. Bonilla-Sierra, M. Elmouttie, L. Scholtès, F. V. Donzé

In the presence of joint sets sub-parallel to a slope face, the stability of the rock mass is controlled by the shear strength of the joints. On one hand, if the joints are persistent their shear strength can be assessed according to Mohr-Coulomb criterion, assuming appropriate values for the cohesion and the friction angle on the joint surface. On the other hand, if the joints are non-persistent with their continuity being interrupted by the presence of rock bridges, their shear strength will increase considerably. In this latter case, the contribution of the rock bridges to the shear strength of the joint has to be accounted for in order to better assess the stability of the rock mass. A numerical analysis of the progressive failure of a rock slope involving a non-persistent joint has been set up based upon simulations performed using a Discrete Element Method (DEM) algorithm specifically enhanced for the modeling of jointed rock masses. Pre-existing discontinuities are explicitly accounted for in the model by using a modified contact logic that ensures an explicit and constitutive mechanical behavior of the joint planes. In addition, rock bridges can be spatially distributed along these joint planes following a prescribed probabilistic technique. Jennings’ formulation (Jennings, 1970) is considered as one of the first rock slope analysis that evaluates the shear resistance to sliding as a weighted combination of the shear resistance of the intact rock and the joint planes. The validity of this formulation is discussed in the present study. Contrary to the Jennings’ formulation, we show that tensile failure is an important mechanism, particularly as the dip angle of the sliding plane increases.

Jan 1, 2015

By G. G. Bowser

PERUSAL of a list of present-day commercial explosives perhaps does not convey a full realization that there has been a great deal of improvement since the original dynamite was discovered nor that, in recent years, great developments have taken place in specialized explosives. This is true particularly of high-explosives for use in metalliferous mining or what is more commonly termed 'hard-rock' mining. Not many decades ago, only two or three types of explosive were avail-'able for commercial use. One was black blasting powder. Another was ordinary nitro-glycerin dynamite in various strengths. Black blasting powder remains with but very little change. Despite its ancient lineage, it is still with us as perhaps the sole explosive in use today which is almost identical in appearance, physical properties, and working ability or execution co the original. Which dynamite the story is different. Its evolution may be likened to that of the dog, nitro-glycerin as first discovered being the counterpart of the wild dog and, like it, dangerous and hard to control. The original dynamite as made by Nobel might then be considered as representing the first domesticaced species. This original dynamite, however, has been 'crossed with other bloods' until one sees now many distinct 'breeds' in the list. Present-day explosives still have the 'bark' and the 'bite', but with control and research have come many improvements; and types have been created which are specially adapted for particular kinds of work. We still have the direct descendant of Nobel's dynamite in the form of an improved nitro-glycerin dynamite. This C-I-L explosive, Polar Dynamite, is no longer the best type to use in the hunt for gold, silver, iron, and other metals. There have been developed other explosives more suitable for chat work. In Canada, such explosives are accomplishing this work effectively, not only where climatic conditions are moderate but through the rigours of our northern winters, with their sub-zero temperatures.

Jan 1, 1938

By S. Eckert, M. Reuter, D. Obiso, S. Kriebitzsch, M. Akashi

The present paper focuses the application of CFD techniques to investigate the Top-Submerged- Lance (TSL) gas injection in liquid metal. Previous works of the authors have shown that up- and down- scaling procedures based on the modified Froude number have some shortcomings, as this approach does not take into account the interfacial and viscous forces. Indeed, surface tension and dynamic viscosity of the smelting slags (σ = 0.4-0.5 N/m, μ = 0.2 Pa·s) are higher than the operating fluids that have been used in literature (water, paraffin oil) to study TSL injection in down-scaled furnaces. In order to get closer to real systems, the authors study the TSL injection of Argon in a liquid metal. An experimental campaign was carried out in the X-ray lab at Helmholtz-Zentrum Dresden-Rossendorf (HZDR), where the eutectic alloy GaInSn was used as liquid phase. The alloy is liquid at room temperature, and X-Ray imaging is used to picture the multiphase flow in a quasi-2D vessel. The aim of the present work is to demonstrate the applicability of CFD techniques to model multiphase flows involving liquid metals, and validate the model using the data produced at HZDR. The commercial software ANSYS Fluent® was used together with the Volume of Fluid model to directly resolve the gas-liquid interphase. Some features of the flow, such as the void fraction distribution and bubble detachment frequency are tracked with CFD and compared to the experimental data. INTRODUCTION In the last thirty years the TSL smelting technology has increasingly been used for industrial non- ferrous smelting processes and is now one of the significant pyrometallurgical processes. Developed in the early 1970’s at CSIRO, the furnace is nowadays commercialized in different market sectors, including copper and lead smelting, zinc fuming, waste treatment and slag recovery (Floyd, 2005). Despite the wide application of these reactors in the pyrometallurgical market, some aspects of the process are still not fully clarified, since in-situ measurements and optical accesses are prohibitive because of the high temperatures and aggressive conditions. Phenomena such as the bubbling regime, the slag solidification and the submerged combustion still need a deeper scientific investigation to obtain a better understanding of the process.

Jan 1, 2019

By Tom Gaines, G. S. Brant, J. G. Debanne

"AbstractThe Bonnie Glen oil field, one of Canada's largest, lies about fifty miles southwest of Edmonton, Alberta. One hundred and thirty-eight wells have been completed in this field since its discovery in January, 1952. Five different procedures have been used in completing the producing wells.The reservoir is an Upper Devonian biohermal reef with good porosity and uniformly high permeability. The top of the reef is quite flat but the flanks slope at angles approaching 20 degrees from the horizontal. The reservoir has a gas cap with a maximum thickness of 400 feet, an oil column of 300 feet, and a :porcus aquifer of over 300 feet. The reservoir pressure is now 2,400 pounds per square inch gauge at datum ( -4100 M.S.L.).Because of the high permeability and the high •pressure, lost circulation and resultant blowouts are a particular hazard in drilling at Bonnie :Glen field. To reduce the dangers of blowouts, it is general practice to run casing to the top of the reef. If the reef is encountered 'high' it was usual practice to run a liner and perforate for completion. Wells penetrating the •reef below the gas/oil interface were either completed in open hole or through casing perforated opposite the oil pay, with the former method more frequently used. Eight wells were completed by the Humble-Otis permanent-type completion, and recently five high wells were completed open hole with the gas •cap exposed. This latter completion, 'tubing submergence', has proved highly satisfactory thus far.The open-hole type of completion is cheaper than the liner perforation method and results in better well performance. More experimentation and data are needed before the tubing submergence method can be recommended unqualifiedly. but all evidence thus far favours its use in reef reservoirs."

Jan 1, 1955

By H. Itou

A mechanism of scorodite formation at ambient pressure was investigated using transmission electron microscopy (TEM). Several types of iron arsenate were obtained from Fe/As solutions (Fe/As = 1.0 and 1.5) at pH values of 1.0, 1.25 and 1.5 at 95°C. Amorphous FeAsO4.xH2O was precipitated from solutions having a higher mole ratio of Fe/As at pH l.5, even after 9 hours. A few micron sized particles were observed by SEM, but these proved to be agglomerates of 10-50 nm amorphous FeAsarxH2O particles when observed by TEM. This means that supersaturation of the solution causes the acceleration of nucleation of iron arsenate hydrate. Crystalline scorodite was obtained from a solution in which the Fe/As mole ratio was unity, at pH l.0 and pH 1.5, after 3 hours. Almond-type crystalline scorodite particles were observed by TEM and most of them showed high crystallinity. The addition of scorodite seed material enhanced the crystallization. Amorphous FeAsO4.xH2O, however, was observed at the surface of the seeds during the early stages of precipitation. It is postulated that crystalline scorodite is not directly precipitated even on crystalline scorodite seeds, but requires a certain time to crystallize on the seed material.

Jan 1, 2006

By R. D. Westervelt

IN JULY 1954, the first iron ore from the deposits in the Knob Lake vicinity was mined and shipped to Seven Islands. The beginning of the production may well be the greatest advance in Canadian economy in the past fifty years. In 1955, the Canadian iron ore output was more than twice that of 1954, an in-crease due principally to the iron ore shipments from the Knob Lake area. Previous to this, Canada's iron production was 1.85 per cent of the world's output. Now, this percentage has risen to approximately 5.5 per cent and shows every indication of increasing further as the production rate from the area is increased. In 1955 the Iron Ore Company of Canada shipped over 7 million tons of iron ore and expects to ship over 10 million tons in 1956. Present facilities may be enlarged to handle up to 20 million tons per year. If the expected I 0 million tons per year are exported, Canada's iron exports will be second only to her wheat and newsprint exports. Before production began from the Knob Lake deposits, years of development were necessary in the area. Geologists spent several summers mapping the general area in order to unravel the complicated stratigraphy and petrology. Particular attention was paid to the mapping of the iron formation and all stages of alteration from fresh iron formation to ore were observed.

Jan 1, 1957

By John H. Fowler

"Most of the aggregate used in Nova Scotia is produced from numerous glaciofluvial and ice-contact deposits scattered throughout the province. Production from bedrock sources is increasing, with most of the coarse aggregate used in the Halifax-Dartmouth area coming from quarries operating within the metro area.A recently completed provincial sand and gravel inventory mapping program has identified some ""resource-poor"" areas where comprehensive aggregate evaluation programs are underway. Although some areas of the province are experiencing aggregate supply problems, large volumes are exported to markets as far away as Bermuda.IntroductionThe Nova Scotia Department of Mines and Energy has been involved with aggregate resource studies for several years, although sand, gravel and crushed stone are not designated as minerals under the Mineral Resources Act of Nova Scotia. Our role has been to provide the aggregate industry with resource data as well as provide similar information to governmental agencies involved with municipal planning, water resource studies and environmental protection regulations. Several private consulting firms use the information in many of their site development studies.We became involved with aggregates in a rather roundabout way. Several years ago, an outcry from inhabitants of a small coastal community over the removal of sand and gravel from a local beach moved the provincial Department of Lands and Forests to take action to protect provincial beaches. We were asked by the Department to provide information and to suggest alternative sources here operators extracting sand and gravel from beaches could relocate. This request initiated an aggregate inventory survey in southeastern Cape Breton, which was later extended to cover the entire province. The initial provincial sand z and gravel inventory survey provided a series of 1:50,000 maps showing the distribution of sand and gravel deposits in the province."

Jan 1, 1982

By A. T. Jakubick, A. MacG. Robertson

This paper reviews key issues related to the placement of dry (soil) covers on extremely weak, compressible fine tailings. The design and construction of soil covers on such tailings often presents a formidable challenge to the geotechnical as well as the environmental engineer due to the low shear strength, poor traffic ability, and high settlement of under consolidated tailings at the time of reclamation. The geotechnical issues to be considered include: (1) consolidation of near-surface tailings to achieve strength gains, improve traffic ability, and allow safe placement of initial cover layer; (2) stability of tailings slopes during dewatering of tailings ponds and/or cover placement; and (3) long-term settlement of tailings and its impact on cover integrity and final surface shaping. The environmental issues to be considered include: (1) management of contaminated (free) pond water; (2) management of contaminated pore water expelled during tailings consolidation; and (3) management of (uncontaminated) surface water on top of the cover. This paper summarizes recent experiences gained in a large uranium tailings reclamation project. It is concluded that a careful consideration of both geotechnical and environmental issues during the planning stages greatly reduces the costs and environmental risks associated with fine tailings reclamation.

Jan 1, 2000