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By Curtin University Western Australian School Mines

"Curtin University’s Gold Technology Group has developed an online CIP/CIL simulation model called SIMCIL which has been used since 1999 to model and simulate industrial leach-adsorption circuits. Recently the model has been upgraded to include an integrated liberation-leach modelling (ILLM) approach which can be used to evaluate the impact of various process parameters (such as grind size, bleed to gravity etc.) and circuit configurations on leach-adsorption circuit behaviour and overall plant gold recovery. A new time-efficient ore characterisation methodology has been researched and developed to provide the required liberation-leach data used in the ILLM approach, which is implemented online for the modelling of gold operations. The model structure, modelling approach, and some scenarios are discussed.INTRODUCTIONCurtin University’s Gold Technology Group has developed an online CIP/CIL simulation model called SIMCIL which has been used since 1999 to model and simulate industrial leach-adsorption circuits. The model has recently been upgraded to include an integrated liberation-leach modelling (ILLM) approach. The ILLM approach provides the means to evaluate the impact of the gravity recoverable gold (GRG) characteristics of the ore (GRG content and liberation behaviour), various process parameters (such as grind size, bleed to gravity, etc.) and circuit configurations on the gravity gold recovery, leachadsorption circuit behaviour and overall plant gold recovery.A new time-efficient ore characterisation methodology has been researched and developed to provide the required liberation-leach data used in the ILLM approach. The data required for the ILLM calibration can be obtained directly from the 3 stage GRG test, leach tests and size-by-assay analysis of the 3 stage GRG test products, and leach test products.This paper describes the ore characterisation methodology, model structure, modelling approach, and the application of the ILLM."

Jan 1, 2016

By J. P. Harrison, K. Gao

It is well known that in situ stress measurements at a given site will generally display significant variability. However, it appears that a robust analysis of such measurements – i.e., one that is faithful to the tensorial nature of the data – is not available. Despite the fact that stress is a tensor, stress magnitude and orientation have long been analyzed separately using classical statistics. In earlier work we demonstrated the applicability of tensor statistics to the analysis of stress variability. Here, we investigate further the difference between tensor and classical statistics with respect to the stress tensor correlation matrix. Our analysis commences with the selection of a series of valid correlation matrices. Then, assuming that standardized tensor components follow the multivariate standard normal distribution, these correlation matrices are used to generate marginal probability distributions of the eigen-parameters (i.e., principal stress magnitude and rotation angle). From these, random stress tensors are generated, their eigenparameters determined, and the probability density distributions of these obtained using both classical and tensor statistics. Our results indicate that, for all correlation matrices, both methods give practically identical distributions for principal stress magnitude. However, the discrepancy between the two methods with regard to probability density distribution of rotation angle is highly dependent on stress component correlation. This discrepancy is usefully quantified in terms of the integral, with respect to orientation, of the difference between the two probability density distributions. This parameter, which we term Area Difference, is closely linked to the magnitude of the correlation matrix determinant, which itself is related to the normal stress correlation coefficient (i.e., ?x ,?y ??). Assuming that Area Difference should not exceed 0.1, we identify the critical determinant for any particular value of normal stress component correlation coefficient. Thus, using published in situ stress data and the obtained critical determinants, we show that for a specific normal stress component coefficient, when the correlation matrix determinant is less than its critical determinant, the more precise tensor statistics should be used to calculate the distribution of rotation angle. These results demonstrate that the customary analysis of stress measurement data may lead to erroneous results, and that tensor statistics appears to be preferred approach.

Jan 1, 2015

By L. Xia, B. Hart, J. Nigim, Z. Chen

"Grinding ore is an important step in the flotation process. Not only does grinding reduce particle size and liberate minerals, it also creates conditions for reactions to occur on particle surfaces that can aide or inhibit flotation. There have been numerous studies examining various grinding regiments and the effect on flotation pulp chemistry, including autogenous grinding and using media of variable composition. There have been however, few studies looking at the effect of variability in grinding media size on pulp chemistry and subsequent flotation. This study attempts to link changes in pulp chemistry in response to variations in grinding media size to flotation recovery. It uses probes mounted in the grinding chamber (pH, Eh, DO, and conductivity) to monitor pulp chemistry changes during grinding of a Cu-Zn ore. Surface chemistry analysis by ToF-SIMS was performed on sphalerite from the mill discharge. Activator and depressant species were monitored on the mineral surfaces and their presence was evaluated in the context of variability in pulp chemistry linked to differences in grinding media and its ball size.INTRODUCTIONIt has been widely recognised that not only does grinding reduce particle size and liberate minerals but the grinding environment has a large effect on the flotation of sulphide minerals. This effect is attributed to Eh change, iron hydroxide coating on surfaces, oxygen reduction, precipitation from solution and galvanic coupling (Grano, 2009). As early as 1960, it was reported that after grinding the ores in an iron mill the natural floatability of sphalerite was reduced significantly (Rey and Formanek, 1960). Kocabag and Smith (1985) studied on the industrial circuits showing that the depression of sulphides flotation in a steel mill is possibly due to the coating of iron oxidation products. Peng, Grano, Fornasiero, and Ralston (2003a, 2003b) found that iron contamination from grinding media plays a dominant role in depressing galena and chalcopyrite flotation. Huang, Grano, and Skinner (2006) reported the same observation in the flotation of arsenopyrite."

Jan 1, 2016

By J. van Deventer

Volatile gold prices in the face of rising costs for mining and refining is causing the mines to look for new ways to reduce costs and increase recoveries. This task is complicated by the fact that the gold in hereto unexploited reserves is associated with increasingly complex ores - either preg-robbing, refractory, associated with high concentrations of copper, or all of the above. Ion exchange resins can play a significant role in this quest for improvement. Although ion exchange resins have been used in Former Soviet Union (FSU) countries for the recovery of gold for many decades, it is still not widely used in the Western World. Synthetically manufactured ion exchange resins can be tailor-made to suit the chemical and mechanical characteristics of a specific application. As such, ion exchange resins can be used in a variety of solution matrices (e.g. cyanide, thiosulphate and acid), and process designs (recovery from clear liquor after solid-liquid separation or directly from the leached pulp). In this paper, a number of applications are discussed along with a review of recent developments in ion exchange technology.

Jan 1, 2014

By George P. Demopoulos, Nima Parsi Benehkohal, Marianna Uceda

Lithium-ion batteries (LIBs) find wide range of applications from portable electronics to electric cars and stationary storage or renewable energy. LIB electrode fabrication is done through mixing the active material (Li-ion host) with carbon (conductive component) and polyvinylidene fluoride (PVDF), which acts as a binder. These components are dissolved in N-methyl-2-pyrrolidone (NMP) to form a paste which is then doctor bladed onto the aluminum current collector. NMP is a toxic chemical and the overall fabrication process remains costly. Efforts are made of eliminating NMP by (1) replacing the binder and (2) using a new fabrication method. Of particular interest among these new methods is electrophoretic deposition (EPD). Via the application of DC potential, particles in suspension can be electrophoretically deposited on different conductive substrates in a relatively fast rate rendering EPD feasible for industrial application. A key aspect for successful application of EPD is the formulation of a stable suspension. Within the McGill HydroMET group, we explore the potential of EPD in fabricating LIB electrodes having demonstrated its effectiveness in the case of P25 nanotitania/carbon anodes. The performance of EPD fabricated TiO2/C electrodes is compared to standard PVDF-based electrodes and shown to have comparable charge capacity. This method is now being extended to other electrode materials. In this paper an introduction to the EPD method will be made and subsequently its use in fabricating LIB electrodes will be described. The performance of the fabricated batteries is evaluated via galvanostatic charging/discharging and cycling tests.

Jan 1, 2016

By Amir Zavichi

Today, with the necessity of timely, on-budget and high quality completion of projects, proper use of construction equipment is essential to ensure project success. Construction equipment places a large monetary burden on the project and if not utilized efficiently, it can result in economic losses. Cranes are one of the most important and expensive operational devices on construction sites. They play a central role, and often activities that rely on crane services fall on the project?s critical path. Currently, material-handling scheduling is done by the crane operator or by an on-duty superintendent using his/hers personal judgment, making the process manual and timeconsuming. Thus, developing an optimal schedule, which considers different dynamic constraints in construction job site, may not be possible based on the current practice. This leads to longer operation times and a negative impact on project cost. This paper presents the latest results of an ongoing study, which aims to design and implement a nearreal time crane operation decision support system to be utilized directly by the crane operator or as an aid for the superintendent in scheduling optimal operation services. This system has several advantages such as maximizing the efficiency of crane operations, guaranteeing the best operation possible to reduce the crane?s travel time, reducing crews and equipment idle time, and minimizing the dependence on subjective human judgments.

Aug 1, 2013

By H. C. Rickaby

Introduction The township of Swayze, from which the Swayze gold area derives its name, is in the Sudbury mining division, approximately 150 miles northwest of Sudbury. The gold area may be regarded as situated at the southwest corner of a triangular area whose northeast and southeast corners are at Porcupine and Shiningtree, respectively, and whose sides are between 70 miles and 90 miles in length. On a geological map, it would be found that belts of Keewatin greenstones and sediments form the sides of this triangle, and that they surround a large granite mass. Prior to the summer of 1931 the Swayze corner of this triangle had probably been less prospected than the other parts and comparatively little was known of it from the standpoint of gold mining possibilities. The extensive belts of iron formation to the south and west of Swayze received some attention about the year 1909, and during the years 1927 and 1928 some prospecting was done in the townships of Greenlaw and Cunningham, south of Swayze, but chiefly for base-metals- copper, zinc, and lead. In the summer of 1931 a very promising discovery of gold-bearing quartz was made by J. G. and J. L. Kenty, working for the Brett-Trethewey Mines, Ltd., in association with Northern Canada Mining Corporation, and Northland Prospectors, Ltd., and this property, now known as the Kenty Gold Mines, Ltd., has been actively developed with very encouraging results. Following this discovery a6d during the summer of 1932 much prospecting took place in the area, as a result of which a number of other discoveries of gold were made, chiefly to the west of the original find. They are distributed over a wide area, which includes the townships of Rollo, Raney, Swayze, Denyes, Halcrow, and Greenlaw.

Jan 1, 1933

By C. Juers

Laboratory chromate coating was applied on AM50 and AZ91D alloys and compared to phosphate-permanganate one. Evaluation of the corrosion behaviour was performed using electrochemical DC and AC methods in ASTM water D1384-87. This electrolyte was chosen because it was moderately aggressive and found to give generally good correlations with long period exposure results in atmospheric conditions. Electrochemical impedance spectroscopy was used to determine more accurately the corrosion rates from the analyses of the high frequency capacitive loop. Anodic polarization was applied in order to evaluate the pitting resistance of the different coatings. These results were correlated with weight loss data evaluated from experiments performed by immersion tests in ASTM water D1384-87 and climatic cyclic chamber tests.

Jan 1, 2006

By R. Aubertin, G. Panneton, P. Donovan

The Detour Lake gold project is located in northeastern Ontario, approximately 300 km northeast of Timmins, within the Abitibi greenstone belt in the northwestern portion of the Archean Superior Province. Historically this greenstone belt has produced approximately 180 million ounces of gold, largely from narrow vein underground mining. The Detour Lake project is a site of extensive past exploration since 1974, as well as underground and limited open pit mining activity from 1983 to 1999. During this period, it produced 1.8 million ounces of gold. Underground mining focused on narrow vein conventional shrinkage and mechanized longhole stoping. After acquiring the property in January 2007, Detour Gold Corporation initiated a comprehensive drill campaign to define the potential for a large, open pitable, low-grade gold deposit. From 2007 to present, Detour Gold has completed over 500,000 metres of diamond drilling. A technical report completed in March 2011 defined an open pit mineral reserve of 14.9 million ounces of gold, which is Canada's largest undeveloped gold reserve. The Detour Lake project is currently in development and infrastructure construction of the mine facilities started at year-end 2010, after all the necessary Provincial regulatory permits were received. Gold production is expected to commence in early 2013. Gold mineralization at Detour Lake is associated with a large scale deformation zone (Sunday Lake Deformation Zone; "SLDZ") that occurs at the contact between the 2.72 Ga Deloro Group mafic metavolcanics and the 2.69 Ga Porcupine Assemblage metasedimentary and metavolcanic rocks. The bulk of the gold mineralization is found in the hanging wall of the SLDZ, which is associated with a stockwork of auriferous quartz veins that splay from a flexure along the deformation corridor. The mineralization forms a 200-350 metres wide auriferous corridor defined over 3 kilometres along the strike of the mafic metavolcanic assemblage, from surface to at least 1,000 metres depth. The richest gold mineralized zones are commonly associated with quartz veins with a strong biotite alteration and local zones of pyrrhotite-chalcopyrite-pyrite-gold enrichment formed during the deformation of the quartz vein system.

Jan 1, 2011

By H. A. Gorrell, S. R. L. Harding

"The potash beds in the Saskatchewan portion of the Williston Basin occur in the upper portion of the Prairie Evaporite formation of the Devonian Elk Point Group. They represent the late stage of a major evaporitic cycle. Two other evaporitic cycles are known in overlying beds, but these apparently never reached the stage of potash salt deposition. The basin in which salt deposition took place extended from the northwestern corner of Alberta southeastward across Saskatchewan into Manitoba, North Dakota and Montana. Deposition of potash salts was apparently restricted to the southeastern portion of the evaporite basin. On a regional basis, five major stratigraphie divisions of the potash-bearing strata have been made. Locally, several of these units may be divided into correlatable sub-units. The potash-bearing strata are separated and overlain by predominantly halite layers of varying thickness. Cross sections show the regional correlation of the potash-rich zones, and maps show the present distribution of the individual potash-bearing zones and the areas of richer development for each zone. The maps tend to substantiate the interpretation of considerable subsurface solution of salt and potash beds."

Jan 1, 1967

By R. Viljoen, K. Manns

"The mining industry instinctively follows rule-of-thumb design velocities often based on very simplistic theoretical “economic velocity” optimization calculations to determine airway sizes. Although these are important building blocks in ventilation planning it should be recognized that mines are far more complex and various, often opposing factors, are at play. Therefore, it is important that each ventilation situation be analyzed on a case-by-case basis to determine the best-fit solution for an operation. The ventilation design process should not necessarily be constrained by theoretical optimal economic velocities that become rules-of-thumb. In some cases, this could lead to unrealistic infrastructure requirements and exorbitant capital expenditure. This type of design often lacks corporate support leading to a scenario where no ventilation upgrades are implemented. Economic velocities typically consider the cost of power, development costs and operational risk. These typical rules-of-thumb work reasonably well as a starting off point when considering feasibility of greenfield projects. For established mines that are looking at expansion these rules may not be appropriate due to capital expenditure constraints or geotechnical ground conditions. The theoretical optimum should be reviewed in the case of an established mine where existing infrastructure could perhaps be maximized. For example, the geotechnical risk of large diameter raises at depth may require multiple small diameter raise to maintain the theoretical economic velocity. If a mine has a life of less than 5 years, then the cost of power is an insignificant proportion of the total owning cost. For these mines, operating the ventilation raises at an increased velocity to avoid a complicated and expensive capital upgrade might be the more appropriate option, even though it opposes the traditional rules-of-thumb. Mines which are capital constrained may be better off accepting a higher operating cost for the interim or settle for minor infrastructure upgrades rather than run the risk of the entire ventilation upgrade not being approved at all. This paper explores a number of examples derived from case studies undertaken by the authors for several deep mechanized mining projects in Australasia. The examples explore conditions under which higher than the economic norm would be applicable."

Jan 1, 2019

By J. A. Harle

Introduction When considering power in Alberta, there automatically come to mind ideas of either hydro or thermal generation, leaving in one's thought an uncertainty as to which one would propose. There is frequently an obvious source of power in some locations on our fastflowing rivers, the major possibilities being described in the report on Surface Water Supply and Water Power of Alberta issued by the Alberta Government in 1948, but it must be realised when reading that report that the sites so described will require extensive geological and other surveys before they can be exploited, and account must be taken also of the transmission distances involved in each instance. From a conservation point of view, where water power can be economically developed and power transmitted to the load centres, this should be done, and our thermal resources should be husbanded for our coming generations, especially if our water resources are falling owing to glacial shrinkage.

Jan 1, 1951

By Z. Farhat

In spite of advances in cutting tool technology, the understanding of the basic wear behavior and failure mechanisms needs further study. Tool wear is the main factor contributing to geometrical error and thermal damage in machined components. Manifested as a reduction in tool life, it also affects the workpiece surface finish, increases cutting forces and induces residual stresses. Furthermore, the emergence of high and ultra-high speed machining processes necessitates the investigation of tool wear under these severe working conditions. Tungsten carbide-cobalt composite material has been used traditionally as wear resistant materials for many years. One main application of this material is in cutting tools. WC-Co tools consist of hard WC particles imbedded in a tough Co matrix, which functions as a binder phase. More recently, Cubic boron nitride (CBN) tool material have attracted special attention due to its high hardness and excellent wear resistance. Boron nitride in its cubic form is known to be the hardest material next only to diamond. In this paper microstructural and tribological properties of commercial grade WC-Co and CBN cutting tool materials are investigated under high speed cutting conditions. The CBN cutting tools were found to be superior to tungsten carbide (WC) tools. Four-fold increase in productivity and significant reduction in chipping and cratering was achieved for CBN as compared to WC. Wear mechanisms are proposed and are related to the observed wear characteristics in the cutting zone.

Jan 1, 2006

By E. Kordzadeh, M. Reza Bateni, M. Karaminezhaad, A. Moeini

A series of austenitic heat resistant Fe-Ni-Cr-Al alloys with different nickel contents have been investigated at 1100 ° C and 25, 50, 50,100 hours in S/0 bearing atmospheres. Before sulphidation test, the specimens were annealed in argon at 1250 °C for 8 hrs. Weight changes were measured using an automatic thermo gravimetric analyzer and corrosion products were analyzed by scanning electro microscope (SEM), energy dispersive X-ray spectrometry (EDAX), X-ray diffraction and optical microscope. The results showed that sulphidation resistance decreased with increasing nickel content. Internal sulphidation controlled by gaseous transport through cracks and pores and the formation of internal sulphide increased when liquid sulphides formed on the surface.

Jan 1, 2004

By Suzie Poulin, N. Geoffroy, G. P. Demopoulos

Most metallurgical industries generate toxic waste that must be treated prior to being released to the environment. However, in a lot of cases, the waste materials are poorly characterized or the analytical results are not well interpreted. These shortcomings often result in the development of inefficient industrial procedures, thus causing economic waste and difficulty meeting environmental regulations. Fortunately, a wide range of analytical techniques are available to guide researchers and engineers into making sound process development decisions. In this work, an industrial selenium and mercury removal process is used as an example to illustrate the application of X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) coupled with Energy-dispersive X-ray spectroscopy (EDX) and powder X-ray diffraction (PXRD) on solid waste. Furthermore, samples of analytical results are presented and interpreted and the modifications to the industrial process that resulted are explained. Finally, a brief description of the advantages and limitations of the aforementioned analytical techniques is given with an emphasis on industrial solid waste material.

Jan 1, 2011

By D. J. King

The development in recent years of a fluidized bed system for use as a counter-current solid ion exchange loading contactor for the purification and concentration of uranium from leach liquors has had a major impact on the design of uranium extraction plants. The main object of this paper is to describe many of the variations that can be applied to the design of uranium extraction plants arising from the use of a fluidized bed loading contactor with a view to providing a guide for the development of a flowsheet for a new uranium extraction plant. The paper has been devoted primarily to the consideration of conventional uranium extraction plants in which a ground ore is leached in mechanically or air agitated tanks. The effect of the use of a fluidized bed loading contactor on each of the plant sections from leach to uranium purification and concentration has been considered. In order to describe most effectively the impact of using a fluidized bed solid ion exchange loading contactor, its use has been compared with the performance that can be achieved with the most common alternative purification processes. The comparisons are made largely on a technical basis, but the effect on the capital and operating costs of the different uranium extraction flowsheets are described qualitatively. In making these comparisons, consideration is given to the effect on the size, number and materials of construction of equipment items and how the quantity and composition of the liquid effluents can be controlled to reduce the environmental problems arising from the disposal of these effluents. The paper also discusses some of the factors that should be taken into consideration in the design of a fluidized bed loading contactor and describes various designs of the elution section that can be used in conjunction with the loading contactor.

Jan 1, 1979

ABSTRACT Understanding process histories and worker exposures in nickel production operations is critical in determining the role nickel compounds play in respiratory cancer incidence. As part of a series on Vale Canada’s (previously known as Inco) nickel processing operations, this paper includes descriptions of Ni electrolytic operations at refineries in Port Colborne, Ontario (1922–1984), and Thompson, Manitoba (1961–present). Industrial hygiene measurements, by area and personal sampling, of workplace aerosols at these operations are reported.

Jan 1, 2014

By William Hawker, James Vaughan, Jeff Chen, Antony van der Ent

"Nickel agromining utilizes hyperaccumulator plants (“metal crops”) to extract nickel from low-grade soils, a process that yields high-grade nickel bio-ore. This feedstock is further processed into a range of nickel products. The bio-ore is relatively free of impurities that complicate the traditional processing of laterite nickel ores. In this paper, current primary nickel processing routes and proposed nickel bio-ore processing options are summarised. A novel pyro-hydrometallurgical route demonstrated at the laboratory scale is described. This process produces a precipitated nickel hydroxide product and takes advantage of the water-soluble basic compounds in the ash to minimise reagent requirements, thereby making it suitable for small-scale implementation in close proximity to the nickel farm. In this process, nickel is precipitated from the leach solution using the basic ash wash liquor. Leaching nickel from ash generated from open air burning requires strong acid and long residence times to obtain high recoveries due to its complex nature and distribution of nickel in multiple phases. This process can be improved by optimising the ashing process with respect to nickel leachability.INTRODUCTIONHyperaccumulator plants have the unique capacity to ‘biopurify’ and concentrate certain trace elements (e.g. nickel) from the soil into their biomass (Reeves 2003; van der Ent et al., 2015). Cultivating these plants as ‘metal crops’ by periodically harvesting and incinerating their biomass generates a high-grade bio-ore (Chaney et al. 1998; Li et al. 2003). This process is called phytomining or ‘agromining’ which is an emerging technology for extracting nickel from sub-economic resources (van der Ent et al., 2015). Potential near-term applications of the technology include implementation on land ahead of processing of the underlying ore-body (Willis 2015), as a mine-site rehabilitation strategy or as an alternative crop for farmers on land that is not suitable for normal food crops. In the longer term, nickel agromining could provide a significant supplement to the nickel supply chain. Critical to the success of agromining is effective bio-ore processing. Due to the unique chemical composition of this feedstock material, existing processes are not very efficient. Our current research efforts aim to develop new process options that overcome limitations of previously trialled routes. In this paper we summarise conventional nickel process routes and proposed new options for producing agromined nickel."

Jan 1, 2016

By A. G. Roach

IT IS generally stated that the gold ores of Nova Scotia are free-milling, and for the most part this is true. However, there is a certain proportion of the gold finely disseminated throughout the sulphides, notably arsenopyrite, and this gold is definitely not recoverable as 'free-milling' gold by amalgamation. The proportion of free-milling gold to total gold seems to vary widely in different localities in the Province and is lowest in deposits of the fissure-vein type. The problem of recovery of these relatively recalcitrant values is usually one of economics, in some plac.es a simple gravity concentrate being of such low tenor that its extraction and subsequent disposal will not bear the costs involved. In other cases, such a high percentage of values escapes from the mortars and plates that concentration is definitely indicated. The size of the mining operation is also an important factor. In the large majority of cases, however, some concentrating step is warranted, even if the resulting concentrate is stock-piled until sufficient has accumulated to justify further treatment.

Jan 1, 1940

By B. E. Halbert, K. T. Himbeault, S. L. Fernandes, R. L. J. Phillips, B. J. Topp

The Beaverlodge uranium mining and milling facilities operated from 1952 to 1981 with about 94% of the ore extracted from the main underground mine and 6% from smaller satellite deposits. Decommissioning work occurred from 1982 to 1985 involving periods of shutdown, salvage and reclamation. Transition phase monitoring, leading to eventual delicencing commenced in July 1985. Over the last 15 years, discharge from the tailings management facility (TMF) and a fresh water stream, impacted during the operational phase by tailings spills, has improved in water quality for most parameters of concern. Loadings to the environment of three key contaminants (radium-226, total dissolved solids, and uranium) have consistently been less than during the operational phase with radium-226 having the greatest variability. Outstanding environmental issues associated with the recovering drainage system formerly used for tailings disposal, are being addressed in an enhanced environmental monitoring program to commence in 2000. Changes in water chemistry and the natural re-introduction of aquatic organisms are issues of concern. In the meantime, application for release from selected satellite areas commenced in 1999. This paper reviews the issues which have arisen during the transition phase, outlines how they have and are being addressed, and provides a comparison of original and current predictions of the recovery process under way at the former Beaverlodge mine site.

Jan 1, 2000