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By Ben D. Thompson

Cemented Paste Backfill has proven to be of critical importance to the operation of a number of Canadian mines, primarily due to the rapid backfilling rate this method permits. In order to improve the efficiency of this backfill system (i.e. optimize binder contents, fill fence design, and the employment of two stage filling strategies) there is a requirement to better understand its geomechanical behaviour. In response, in-situ experiments have been conducted in long-hole stopes to quantify the evolution of total earth pressures and pore pressures at a series of instrumented points within both the core of the backfill and close to fill fences. The deflection of fill fences as a result of paste loading has been measured and additional instrumentation has also been employed to measure cement hydration, negative pore pressures, and blasting induced vibrations within fresh and cured paste backfill. Installing geotechnical instrumentation within an open long-hole stope can be an extremely complex procedure and this paper details the methods that have been successfully employed. Preliminary results are presented, and the pressures induced by backfill with differing binder contents, at a number of different in-stope locations are considered.

May 1, 2009

?Founded in 1969 by the Ruia family ?Diversified global business corporation with a balanced portfolio of assets in the manufacturing and service sectors; $15 Billion revenue in FY 2009-2010 ?Employs 70,000 people worldwide with offices in Asia, Africa, Europe and North America

May 1, 2011

By Yuanming Pan, Brett Rogers, Baoquan Hu, Gary Yeo, Christine Austman

The nature and distribution of radiation-induced defects (RIDs) in quartz from the Maw Zone, a yttrium- and rare-earth-element-enriched sandstone breccia complex exhibiting intense hydrothermal alteration, have been investigated by electron paramagnetic resonance (EPR) spectroscopy. EPR spectra show that detrital quartz in sandstone, from five diamond drill holes intersecting the Maw Zone and one above the crest of the so-called Quartzite Ridge, contain only background-level RIDs, indicating that Ubearing fluids were absent in this area. However, close to the sandstone-basement unconformity, in hole WR-194 immediately west of the Quartzite Ridge, the concentration of RIDs in detrital quartz is significantly above background but at least an order of magnitude lower than those at the Key Lake and McArthur River deposits. Widespread drusy quartz at the Maw Zone, which signifies intense hydrothermal alteration, is associated with hematite-, sulfide- and carbonate-bearing mineral assemblages, which exhibit complex crosscutting relationships. EPR spectra of drusy quartz in all three types of mineral assemblages are low in RIDs as well, supporting the EPR evidence that fluids at the Maw Zone did not carry significant U. These EPR results suggest that, in spite of intense hydrothermal alteration and favorable structural geology, the Maw Zone is unlikely to host any significant U mineralization. Moreover, this study shows that the EPR technique is potentially a useful exploration tool, capable of determining whether individual alteration zones in the Athabasca Basin were associated with U-bearing fluids or not.

Jan 1, 2013

By J. N. Hilton, D. Moffett, E. Barnes

"A recent pilot-plant program carried out at Rio Algom's Quirke uranium mine at Elliot Lake, Ontario is described. The goal of the research was the production of tailings basin effluents which were low in total radium-226. The process tested involved precipitation of radium with barium chloride and sedimentation in plastic-lined settling ponds. Adjustment of the tailings basin overflow from its normal value of pH 9.5 by addition of sulphuric acid to about pH 7.5 was found to give approximately a five-fold improvement in total radium-226 removal. A five-month demonstration test resulted in an effluent with a mean total radium-226 activity of44 pCi/L after 2.5 days settling time and 29 pCi/L after 5 days. The results from the demonstration program are used to propose a schedule of achievable total radium-226 activities where precipitation and sedimentation are employed. The maximum suggested values for 5 days nominal settling time are: 30 pCi/L in an annual mean, 45 pCi/L in a monthly mean. 60pCiIL in a weekly mean and 80 pCi/L in any single grab sample.IntroductionRadium-226 has been removed from effluents at the Elliot Lake uranium mines since the introduction of the first barium chloride treatment system in 1965. Current practice, which has changed little over the years, consists of radium-barium sulphate precipitation by the addition of a low do se of barium chloride to the clear overflow from the tailings basin(l·2l. Provision is made for the precipitate to settle in large natural or constructed ponds and lagoons. The residence time in these ponds, which depends on the site, ranges from 3 to 35 days, with varying degrees of efficiency being achieved."

Jan 1, 1981

By C. H. Ash

"Abstract-The Red Chris Cu-Au deposit (522.7 Mt at 0.35% Cu and 0.27 g/t Au), northwestern British Columbia, is one of several pre-accretionary porphyry systems in the Cordillera of western Canada. It is hosted by an Early Jurassic hornblende monzonite to quartz monzodiorite porphyry which forms part of a suite of dikes and stocks that intrude Late Triassic volcanic strata. Major and trace element chemical data suggest that these Early Jurassic intrusions have compositions which fall on the boundary between alkalic and calc-alkalic compositions. Alteration and mineralization in the Red Chris deposit are more typical of calc-alkaline porphyry systems with abundant potassic, sericitic and argillic assemblages and quartz-rich stockworks. It lacks Na- and Ca-bearing silicate assemblages which characterize the alkalic porphyry deposits of British Columbia. One of the more unusual features of the deposit is the abundance of carbonate alteration and veins which occur throughout the hydrothermal history of the deposit. This type of alteration and veining is more typical of alkalic porphyry deposits. The composition of the carbonates vary both temporally and spatially with different alteration zones. Potassic zones, which are characterized by orthoclase±albite±quartz±chalcopyrite±bornite± magnetite±hematite and Au/Cu ratios of 1:1 (g/t Au:% Cu), contain minor siderite veins and alteration. Quartz-sericite-carbonate (QSC) zones overprint earlier potassic alteration and comprise quartz+ankerite+sericite+pyrite+chalcopyrite with Au/Cu ratios of 0.5:1 (g/t Au:% Cu). Ankerite is the main carbonate in this stage but has a variable composition with a more Fe-rich variety associated with mineralized veins. Localized chlorite-carbonate alteration zones, characterized by chlorite+ carbonate+quartz±kaolinite±pyrite±gypsum and high Au/Cu ratios [2 to 3.5:1; (g/t Au:% Cu)], contain predominantly calcite. Late stage carbonate-gypsum veins have an ankerite to dolomite composition which is very similar to the regional carbonate alteration and veins."

Jan 1, 1997

By T. E. Smith

"This paper describes the application of a motor-driven flywheel unit, known as a peak shaver, to compensate for the cyclic load fluctuations of a large electric dragline installed at Pine Point Mines, near Great Slave Lake in the Northwest Territories. Of particular interest in this application is the fact that the power system supplying the dragline is a relatively small isolated system, with the major generating source approximately 170 miles from the mine.The cyclic load fluctuations of the dragline are theoretically capable of producing a maximum swing of up to 11 megawatts, which approaches nearly 50% of the installed generating capacity. To reduce these load fluctuations to acceptable limits various alternatives were considered, leading to a decision to install a peak shaver to optimize the operations of both the mine and the power system. Without the peak shaver, the dragline operations would be severely curtailed and additional diesel generation would have to be run at considerable expense, otherwise the power system frequency fluctuations would be totally unacceptable. With the peak shaver, power and frequency fluctuations are kept within tolerable limits, and optimum economic operation of the diesel generation is obtained.The paper outlines the steps leading to the selection of the peak shaver as the compensating device, describes the equipment installed and gives details of operating experience with the dragline/peak shaver combination since installation early in 1979. This .peak shaver is the first of its kind in North America, the only other peak shaver installation being in Australia.IntroductionPine Point Mines Limited owns zinc-lead mining and milling operations located at Pine Point, Northwest Territories, 5 miles south of Great Slave Lake (Fig. I). The company is staffed and managed by Cominco Ltd., which has a 69% interest in Pine Point Mines.Mining activity in the Pine Point area was first recorded in 1898, when the Yukon gold rush was on, but when the zinc/lead showings in the Pine Point area did not yield much in the way of gold, interest in the area soon waned. Cominco Ltd. first acquired some claims in the Pine Point area in 1928, but interest was sporadic until the early 1950s, when extensive exploration indicated rich pockets of zinc/lead ore near the surface. Pine Point Mines Limited was formed in 1951, with Cominco acquiring a majority interest in the company."

Jan 1, 1980

By S. N. Dixon

"Maximizing the value of each tonne of processed ore is the goal for all operations. Cyanidation processing of gold-copper ores has been challenging since its first use in 1889. The current practice treats a bleed or the total flow of mill solution to recover copper as copper sulfide (by sulfidization, acidification, recycling, and thickening), or to recover the cyanide (by acidification-volatilization neutralization). The process presented uses the adsorption of copper cyanide by carbon and the selective elution of copper from carbon to concentrate copper into a smaller stream. Copper contained in the smaller stream is precipitated as copper cyanide.RÉSUMÉ Toutes les exploitations ont pour objectif commun d’optimiser la valeur de chaque tonne de minerai traité. Depuis sa première utilisation en 1889, la méthode de traitement par cyanuration des minerais aurifère et cuprifère s’est révélée complexe. La pratique actuelle traite la saignée ou le débit total d’une solution de traitement du concentrateur pour récupérer le cuivre sous la forme de sulfure de cuivre (par sulfuration, acidification, recyclage et épaississement), ou pour récupérer le cyanure (par acidification, volatilisation et neutralisation). Le procédé présenté dans cet article utilise l’adsorption sur charbon actif de la solution de cyanure de cuivre et l’élution sélective du cuivre depuis le charbon pour concentrer le cuivre en un plus petit jet. Le cuivre contenu dans ce plus petit jet est précipité sous forme de cyanure de cuivre.INTRODUCTIONProcessing gold-copper ores by cyanidation has been a cost-control challenge since the cyanidation process was first used in 1889. Copper cyanide is stable only in the cuprous state, not the cupric. This factor results in the oxidation of a mole of cyanide per mole of nonchalcocite copper extracted. Each mole of copper extracted forms a cyanide complex with a minimum of 3 mol of cyanide. This cyanide-to-copper mole ratio is required to dissolve gold. The oxidation of cyanide and copper complexation with cyanide results in high cyanide consumption for copper-gold ores, which is a significant operating cost.One challenge in processing gold-copper ore is the cost of cyanide related to the extraction of copper. Processing 10,000 t/d of ore containing 1,000 mg/kg copper and 10% copper extraction yields 1,000 kg/d of copper. Currently, processes to remove copper from cyanide leach solution treat either the total flow of the barren or a bleed of the barren. The two processes used for copper-gold ores are sulfidization, acidification, recycling, and thickening (SART), which produces a copper sulfide product for sale; and acidification- volatilization-neutralization (AVR), which recovers the cyanide from a gas and produces a low–cyanide content solution. This low–cyanide content solution can be recycled to the process or might require additional treatment before being disposed from the operation."

Jan 1, 2017

By Troy Boisjoli

Since its discovery in February 2014, the Arrow Uranium Deposit has undergone rapid development through aggressive and systematic drilling programs and is now being progressed through advanced engineering and permitting. Based on the 2018 NI 43-101 Technical Report, the Probable Mineral Reserve estimate totals 234.1 million (“M”) pounds (“lbs”) triuranium octoxide (“U3O8”), contained in 3.43 M tonnes at an average grade of 3.09% U3O8. The proposed processing plant at the Rook I Project (the “Project”) will be capable of producing up to 31 M lbs of U3O8 per year, with a projected mine life of nine years based on the Probable Mineral Reserve estimate, although NexGen is permitting a 24-year operating life at the Project assuming the majority of Inferred Mineral Resources are upgraded to Indicated Mineral Resources with continued mineral resource development drilling. The Project will be developed through transverse and longitudinal longhole mining methods, pairing primary and secondary stoping techniques with a high degree of equipment mechanization which will provide a combination of good productivity, high extraction, and stable back support. This next generation of uranium operations combines the use of advanced tele-remote equipment and instrumentation with a low-cost bulk mining method and a best-in-class tailings management practice, effectively reducing operating costs and setting a new standard for elite environmental and social practices.

Jan 1, 2020

By Peter Hayes, Evgueni Jak, Taufiq Hidayat, Gary O’Connell, Denis Shishin, Jeff Chen, Francis Letarte

"Knowledge of slag properties is required for the optimisation of smelting operations. The phase equilibria and viscosities of the Al2O3-CaO-FeO-Fe2O3-MgO-MnO-NiO-Cr2O3-SiO2 slags at conditions of interest to Koniambo Ni-laterite smelting operations have been investigated. High-temperature re-equilibration phase equilibrium experiments of industrial slags followed by rapid quenching and direct measurement of phase compositions using electron probe X-ray microanalysis (EPMA) have been undertaken in the olivine and pyroxene primary phase fields at temperatures between 1475 and 1600°C and SiO2/MgO weight ratios between 1.57 and 2.09. Phase equilibria predictions were performed using FactSage thermodynamic software. A slag viscosity model available in the FactSage thermodynamic package has been used to calculate the viscosities of the liquid slags. The Einstein-Roscoe equation combined with the predicted phase equilibria data have been used to estimate the viscosities of the slag slurries (slag + solids). The information provided can be used to assist in the evaluation of the furnace performance, to assess further optimisation of slag composition and to explore possibilities of targeted feed changes.INTRODUCTION One of the key steps in the production of ferronickel from nickel laterite ore at Koniambo Nickel SAS involves reduction and smelting of pre-dried nickel-bearing saprolitic ore (high Mg and Si) in an electric furnace at temperatures up to 1650°C. The characterisation of the slag properties as functions of key operational parameters, such as, temperature and composition, including liquidus, the proportions of solids and viscosity, is essential for improving control and optimisation of the operations. The slag produced in the smelting process is a complex oxide system with the major chemical components including Al2O3, CaO, Cr2O3, “FeO”, MgO, “MnO”, “NiO” and SiO2. Characterisation of these multi-component systems using a solely experimental approach becomes increasingly complex as the number of components is increased."

Jan 1, 2017

By K. B. Young

Possibly the most complex fatigue problem associated with the development of the axial-flow 'gas turbine is discussed in its broader aspects from the metallurgical viewpoint. Reference is made to nodal patterns, interference diagrams, etc. The use of such data in analysis of a turbine :blade failure is illustrated. Special attention is given to the influence of some metallurgical variables affecting fatigue strength and, in particular, heat treatment is shown to have a pronounced effect on .the relative fatigue and creep strength properties of a nickel-chromium-cobalt base alloy suitable for turbine blade applications.

Jan 1, 1958

By Rob Assabgui

Presentation Overview ? Stobie Mine Sublevel Cave Background ? Elevated Silica Levels ? Silica Control ? Challenges and Issues ? Conclusions

Oct 1, 2010

By T. Ouellet, F. Chiesa, J. Carignan, D. Levasseur

Common practice for the preparation of permanent mold for aluminum casting is to coat the mold with a ceramic suspension to obtain a chemically stable interface with the aluminum melt. This practice serves two purposes: first, it helps the thermal regulation of the mold and second, it prolongs its life. The possibility of increasing the coating durability by applying it by thermal spray is appealing. Plasma spray of zirconium oxide based coatings was performed on H13 tool steel to study the coating’s thermal fatigue resistance. A unique dip test setup was used to characterize the thermal fatigue resistance of the coatings and of bare H13 steel. Observations of the failure mechanism bring an insight on the requirements of the coating to maximize its durability.

Jan 1, 2014

By Yihan Liu, Jintao Zhang, Chen Xiao, Xiaomeng Zhao, Guanglei Song

To estimate the performance of the inert anode materials based on NiFe2O4 spinel ceramic during it used for aluminum electrolysis, we investigated the wetting process of cryolite molten salt which is in composition of industrial aluminum electrolysis with carbon anode and NiFe2O4 based cermet materials, by means of determination the interface wetting angle between the molten cryolite electrolyte and the solid anodes interface. The results show that the wetting angle between the electrolyte and carbon anode is larger than 90 angulation, this means that they basically can not wetting; however the nickel ferrate spinel ceramics behaves much better. In regard to the NiFe2O4 matrix materials, their initial wetting angles is 76.9. The initial wetting angles for 1.0wt%MnO2, 2.5wt%TiO2 and 0.5wt%V2O5-doped samples are respectively 56.86°, 52.98° and 51.93°. However, after 50s later, all the wetting angles came down below 15°.

Jan 1, 2015

By J. -M. Lalancette, D. Lemieux, C. Chouinard

"A gold bearing concentrate containing 107 g/T of gold, 9.3% copper and 706 ppm of mercury was processed at the demonstration scale for the extraction of gold and copper using a cyanide free process. The concentrate was generated through flotation to upgrade the gold and copper grade, but also showed contamination with mercury. This concentrate was submitted to the DST process demonstration plant. The concentrate was first oxidized using a fluidized bed to produce a calcine. The mercury was volatilized during the oxidation stage with an efficiency higher than 98%. The mercury was condensed and removed from the sulfuric acid using a thiosulphate process. Copper was extracted from the calcine as copper sulphate using diluted sulfuric acid. The solid remaining after acid leaching was submitted to the DST chlorination process for gold extraction. Under optimized conditions, a gold extraction of 97.3% was achieved in the chlorination reactor. Gold was recovered from the pregnant brine by precipitation on silica using a DST proprietary process.INTRODUCTION Dundee Sustainable Technologies Inc. (DST) offers proprietary metallurgical processes for the treatment of material from the mining industry. DST processes enable the extraction of precious metals and for the removal and stabilization of contaminants, such as arsenic, from ores and concentrates. DST provides environmentally-friendly, viable and efficient processes, capable of handling complex and refractory ores which cannot be processed with conventional approaches due to metallurgical issues or environmental considerations. Several mining jurisdictions around the world have banned or restricted the use of cyanide. DST has developed a closed loop chlorination process as an alternative to the conventional cyanidation process for the extraction of precious metals from minerals. The tailings from the process are inert from toxic substances such as cyanide and organic compounds, are sulphide depleted which means they do not generate acid, and thus, meet and/or exceed environmental norms. The process has demonstrated excellent gold recoveries within a fraction of the time needed for cyanidation to obtain similar results. Moreover, the closed loop process does not generate any liquid effluent and does not consume much water: it only requires a water make-up to compensate for moisture leaving with the tailings and by-products, and seawater may be used. The improved environmental footprint of the DST process has been certified by the Environment Technology Validation program (ETV) which provides an independent evaluation of the performance claims of innovative technologies."

Jan 1, 2017

By Charles S. Ney

"THE WRITER'S acquaintance with Kootenay King mine is limited to a brief geological excursion in the vicinity. This paper has been compiled largely from maps of J. Sullivan, mine geologist in 1952, kindly made available to the writer by Transcontinental Resources; a 1942 private report by W. L. Brown; and personal communications with J. Sullivan. Remarks on regional geology, and the comparison with Sullivan mine, are specifically the writer's.The Kootenay King mine is situated in the westernmost range of the southern Canadian Rockies at an elevation of 7,300 feet. From the Sullivan Mine at Kimberley, B. C., it lies 19 miles due east. Six miles of this distance are represented by the pronounced topographical and structural gap of the Rocky Mountain Trench. Mineral claims were locat-ed in the area prior to 1898. The deposit was first seriously explored in the late 1920s, and a small orebody was then outlined and developed. Mining and milling were undertaken in 1951.52. The orebody, amounting to about 14,000 tons, was mined out, and no significant new ore was revealed.The orebody is a replacement of dolomitic argillite by fine-grained galena, sphalerite, and pyrite. The sulphides are finely laminated in the direction of bedding, following out minor folds faithfully. The grade of ore estimated from diamond drill holes (W. L. Brown, 1942) was 11 ·I per cent zinc, 11 ·I per cent lead, and 3·8 ounces per ton of silver. The mineralized zone extends about 250 feet horizontally, 160 feet vertically, with a width of six to twenty feet.General GeologyThe country rocks are sediments of the Aldridge formation of late Precambrian age. For several thousand feet stratigraphically above and below the mine, the formation consists mainly of thinly laminated argillite and siltstone. Several horizons contain appreciable carbonate. About 2,800 feet stratigraphically below the mine, predominantly dolomitic beds mark the top of the underlying Fort Steele formation. The medium-bedded fine quartzites, which characterize about 10,000 feet of the Middle Aldridge in the Purcell range, have a restricted development amounting to only 2,000 feet in the Rocky Mountains. This member is about 2,200 feet above the mine horizon."

Jan 1, 1949

By Earl Gebhardt

"The planning and design of mining panels in the Potash Corporation of Saskatchewan Inc., Lanigan Division mine Block B involved a number of investigative techniques. The techniques utilized to gain insight into the viability of mining included2-D and 3-D seismic surveys, longhole drilling, exploration wells, photo lineament, magnetic and gravity surveys, and actual room excavation.IntroductionPotash Corporation of Saskatchewan Inc. (PCS) owns and operates four potash mines in the province of Saskatchewan. The Lanigan Division mine is located 110 Ian east of Saskatoon, Saskatchewan, near the town of Lanigan.The Lanigan Mine commenced production in August 1968under the ownership or Alwinsal Potash of Canada Limited. The mine was purchased by PCS in 1977.Lanigan Division's productive capacity is 3.4 million tonnes of product per year. Ore is extracted from the "" B"" zone or Layer III or the Patience Lake member of the Prairie Evaporite, more than 1000m below surface . The Patience Lake member (approximately 20 m thick) consists of potash interbedded with salt. The average run-of-mine ore grade is 21070 K20 (Fig. I).The mine was initially developed using the room-and-pillar technique. Improvements in mining resulted in the use or extensible conveyors in long panel rooms."

Jan 1, 1993

By N. A. Duke, R. L. Carpenter

Abstract - The West Meliadine area is underlain by structurally interleaved panels of mafic and minor ultramafic metavolcanic rocks and metasedimentary rocks that occur along the northern margin of the Neoarchean Rankin Inlet greenstone belt. Three structural and metamorphic domains are recognized: (1) the easterly Wesmeg domain; (2) the central Barracuda-Ridge domain; and (3) the westerly Peter Lake domain. The Wesmeg domain is characterized by a series of southeast-trending, north-dipping, foliation-parallel panels of greenschist facies mafic metavolcanic and metasedimentary rocks. The Barracuda-Ridge domain is comprised of greenschist to amphibolite facies mafic metavolcanic rocks that define an east-northeast-trending structural grain. The Peter Lake domain consists of amphibolite facies mafic metavolcanic rocks and minor metasedimentary rocks intruded by a monzonite pluton. West Meliadine hosts the economically significant Wesmeg gold deposits, as well as other important gold showings across the Barracuda-Ridge and Peter Lake domains. The geological setting of the Wesmeg gold deposits resembles that of a break or fault zone. The Pyke Break is a major geophysical discontinuity (>65-km strike length) and is the first-order structural control on gold mineralization at West Meliadine. It is several kilometers wide and characterized by polyphase deformation and shear zone development accompanied by lode-gold mineralization. In general, gold concentration is related to quartz and iron-carbonate veining, iron sulfides (mainly arsenopyrite and pyrrhotite), and accompanying silicate alteration minerals that overprint favorable chemical and structural traps late in the history of deformation.

Jan 1, 2004

By Eugene F. Mehr, Dennis C. Martin

"Development of the final slope for the 340 m (1200 ft) high hanging wall at Cassiar Mine precipitated an area of deep seated instability involving an estimated 17.6 million tonnes. The deformation mechanisms involved squeezing of soft deformable serpentinite rocks in the toe which caused planar sliding and graben toppling of the stronger sedimentary rocks in the middle and upper sections of the slope. Although movement rates up to 150mm/day were recorded, by understanding the controls on failure, the mine was able to install a suitable monitoring system and complete the open pit with only minor loss of the mineable ore. Accelerated mining was required in the last full year of operation. This paper describes the deformation behaviour, failure mechanisms and back analysis results for the failure. The monitoring systems and operational aspects related to the failure are also presented.IntroductionCassiar Mine is located in steep mountainous terrain in northern British Columbia approximately 1200 km north of Vancouver (Fig. I). During the final mining phase of the open pit, instability developed in the approximately 340 m high hanging wall (east wall) slope. A unique graben toppling mechanism was identified based on detailed assessment of slope monitoring data and visual observations. Comprehensive slope monitoring enabled mining to continue even though movement rates as high as 150 mm/day were being recorded. Three-dimensional limit equilibrium back analyses and numerical modelling have been used to assess the various controls on the slope movements and to understand the failure mechanism."

Jan 1, 1993

By W. N. Hamilton

"Evaporites abound in the Western Canada sedimentary basin, recurring throughout the stratigraphic column and widely scattered over the basin region. Alberta, situated centrally over the basin, includes many of the evaporites within its borders, but only a few have the right geological conditions to form potential economic deposits of salt or gypsum. These include the Middle Devonian Elk Point Group and related evaporites, Upper Devonian Wabamun Group-Palliser Formation evaporites, and evaporites of the 'Triassic Charlie Lake and Whitehorse formations.Salt deposits underlie almost half of Alberta. The major deposits belong to the Elk Point Group, which includes thick salt units in the Lotsberg, Cold Lake and Prairie Evaporite formations. Another, younger salt deposit in the Wabamun Group has only local distribution. Elk Point salts have a maximum aggregate thickness of 430 m in east-central Alberta. The deposits deepen southwestward across the province, from minimum depths of210 m at Fort McMurray to 1820 m at Edmonton.The thickest, most extensive salt deposits are the upper Lotsberg and Prairie Evaporite salts. Both have excellent development potential. The upper Lotsberg is up to 150 m thick, consists of clear, very coarse crystalline halite with only minor impurities, and has a notable lack of non-salt strata in its succession. Analytical data for the Lotsberg Salt show extraordinary chemical purity. Prairie Evaporite Salt differs lithologically from the Lotsberg in having a significant non-salt component. The deposit is up to 200 m thick and consists of medium crystalline halite, brownish coloured and cloudy as a result of finely dispersed impurities. The main impurities-shale, anhydrite and dolomite-are most prevalent as interbeds in the salt succession, ranging from very thin laminae to beds several metres thick. Although of lesser purity, the Prairie Evaporite Salt is shallower, thicker and more extensive than the Lotsberg and the salt quality is quite acceptable for most industrial uses."

Jan 1, 1982

By K. Murase

Potentiostatic electrodeposition behavior of dendritic copper from acidic copper(I) chloride (cuprous chloride) baths containing sodium chloride and sodium bromide was investigated. The morphology, or appearance, of copper dendrite and the sodium content in the dendrite as an impurity were both influenced by deposition potential (0 to ?150 mV vs. SHE) and bath temperature (R.T. to 60 C), while the current efficiency for the deposition was 99% or more irrespective of the deposition conditions examined. The bath pH did not affect the deposition behavior in the pH range of 0 to 2. Bath temperature was found to be the most important factor influencing the deposition current. The current density of the dendrite deposition on a titanium cathode was lower than that onto a copper cathode with the same substrate surface area. The reproducibility of the current for the dendrite deposition was poorer when an as-polished titanium cathode was used, although it was improved by surface treatment of the cathode with an HF-HNO3-H3PO4 solution before electrodeposition. The deposition behaviors were discussed with the potential-pH diagram of the Cu-Cl-H2O system.

Jan 1, 2007