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By L. C. DeCory

"Concrete is a common denominator to the building process and portland cement is an integral and necessary component of concrete. The cost of portland cement is nominal and its cost comprises, in most instances, a small portion of the total cost of ""put-in-place"" concrete.The domestic demand for portland cement in Canada is projected to be slightly less than 11 million short tons in 1980. In order to achieve this projected goal, stabilization or lowering of the cost of put-in-place construction is necessary. This enhancement of the cost of building can be achieved by:(1) improving the building process;(2) refining and improving design techniques; and(3) developing improved and economical concrete products.Some of the techniques and materials that will lead to building cost stabilization include systems building in its broadest sense, slipforming, precasting, prestressing, computer design, lightweight aggregates, fibrous concrete and integration of building components."

Jan 1, 1973

By Frank Martonhegyi

"The objective of this paper is to review the coal basins in the Canadian part of the Western Cordillera to aid their understanding, and to aid in finding and proving places of economic coal mining potential. Coal occurs in eugeosynclinal basins in the Western Cordillera which evolved through three stages: -from systems of volcanic arcs in the Late Jurassic to mid-Cretaceous; -through an intermediate stage with deposition in increasingly restricted successor basins in Jurassic to Early Tertiary; -to a continental stage by the Eocene. Minor coal seams occur usually in late volcanic arc stage sediments bur they can be locally thick as they are on Queen Charlotte Islands. Successor basins usually show a marine-paralic-limnic evolurion. Signijicanr coal deposits occur in the tarter two sequences in the Whirehorse (Tantalus) and Bowser (SkeenaSusrur) basins. Currenr activities are intensive in the more accessible Bowser Basin, for example at Telkwa, Susrut River and on the Groundhog coal field. On Vancouver Island major coal seams occur in cyclic sediments, but the more accessible deposits are mined our. Exploration renewed recently in the less accessible northern part of the Island, for example Quinsam, for surface mineable coal. The Western Cordillera is a mosaic of allochtonous tectonic blocks. They originated from the south and were displaced northward by several hundred kilometres. Many Tertiary coal basins are related to strikeslip transcurrent faults along which the later part of displacement took place, for example the Dawson coal area in the Tintina Trench. Tensional and dipslip normal faulting also created or enhanced sites for thick peat accumulation. For example at Hat Creek 280 m of coal occur in a 550 m section. Secondary structures are often better exploration targets than the main fault zones. Pluvial and alluvial fan environments away from the main drainage are usually the favourable sites for thicker and cleaner coal deposition."

Jan 1, 1985

By Klau Meyer

"At Teck-Corona Operating Corporation's David Bell Mine, a successful water quality management strategy has been established. This resulted from the development and application of process technology, allowing year round discharge of an effluent exceeding the chemical and biological standards set by the Ministry of Environment. This strategy aims at minimizing contaminant levels of effluents through optimization of reagent selection and reduction of effluent volumes through maximizing reclaim water usage. Concentrator and effluent treatment plant operating practices, process chemistry and the results of the water quality management strategy are reviewed.IntroductionThe David Bell Mine is located in the Hemlo gold camp 42 km east of Marathon, Ontario. The concentrator has a design throughput of 1000 tonnes per day. The processing of the run of mine ore ( - 15cm) involves the following unit operations: grinding in a semi-autogenous mill followed by a ball mill, thickening, pre-oxidation , cyanidation, and carbon-in-pulp gold recovery followed by electrowinning and refining.The David Bell Mine water quality management strategy is composed of the following items (Goodfellow and Meyer, 1991):• natural destruction of cyanide contained in the tailing water in a large shallow tailing pond ;• preliminary treatment of reclaim water in the grinding circuit for cyanide and heavy metal removal;• pre-oxidation of sulphide minerals in pipe reactors to reduce cyanide consumption using pure oxygen;• pH control in the grinding, pre-aeration and leach circuits to minimize the dissolution of stibnite while maximizing gold recovery; • close control of cyanide addition rates to the leach circuit to maintain the lowest possible levels;• a carbon column for gold recovery;• an effluent treatment plant for antimony and heavy metal removal; and• the use of final treated effluent for industrial water underground to minimize fresh water consumption."

Jan 1, 1992

By Jeremy Breker

Cameco aligns its social and environmental responsibilities with its vision, mission and values. Environmental Leadership is established as a corporate objective that emphasizes the triple-bottom-line and a systematic approach to understanding environmental, social and economic issues, risks and opportunities. These are ingrained in the project culture, systems and processes and used to influence solutions derived by the project teams to achieve Cameco's objectives. This paper traces the organizational objectives from the early stages of a project through to implementation and turn over to Operations. A case study is used to demonstrate how an asset is influenced by Cameco?s strategy.

Aug 1, 2010

By Y. L. Mehta

The working experience of the Zinc Smelter, Debari, Udaipur with process modifications and iron control practices is described in detail in this paper. Most of the modifications were made at different times as part of capacity enhancement campaigns that led to distinct advantages, thereby increasing both zinc production and recoveries. This smelter came into existence in 1968 with a humble beginning of producing 18,000 metric tonnes (MT) of zinc per annum, using the conventional batch hydrometallurgical roast-leach-electrowinning technology. Zinc production capacity was increased stepwise to 45,000 MT, 49,000 MT and 59,000 MT, by making suitable process modifications and adopting new technologies, particularly in the leaching section. During these modifications, the process of iron separation as Moore cake was also changed to jarosite cake production. At present, jarosite is being disposed in a secured landfill at the Zinc Smelter, Debari (ZSD) and as Jarofix at the Chanderiya Lead Zinc Smelter (CLZS). As a result of subsequent in-house performance improvement and debottlenecking campaigns, this smelter could achieve further increases in production. Zinc production for the financial year 2005-06 was 81,000 MT.

Jan 1, 2006

By A. J. Hargraves

"It is difficult to quantify comparatively the gassiness of a property. The most common index to gassiness, cubic feet of gas per ton of coal mined, is very arbitrary and does not take into account the geological setting nor the mining operation. The gassiness of a virgin coal in situ can be assessed, but no method is precise and the most accurate methods involve prolonged field and laboratory experiments. In general, gassiness increases with depth. Whereas 'gas' normally implies methane, other gases such as nitrogen, carbon dioxide, etc. may be present in seam gas also. The inflammability of methane is a problem, particularly the explosibility of a methane-air mixture; also oxygen dilution is involved in high gas concentrations and some gases are poisonous even in low concentrations. Cross measuring into a virgin seam is usually not as troublesome as development in the seam, where narrow openings may require strong ventilation to dilute gases exuding from the face and sides. Total extraction presents problems of gas from the working seam, or from adjacent seams, particularly at the return side, or of gas-laden air from the goaf streaming out or sometimes surging out intermittently, again on the return side. In pillar extraction or longwall retreating special roadways may be required to allow the side-to-side and end-to-end flushing of the goaf which is somewhat inherent in longwall advancing. Layering may occur, particularly where ventilation conditions are not brisk. Outbursts of gas from adjoining seams may be induced by sudden rupture of roof or floor in caving workings. Outbursts of coal and gas from the working seam may occur, mostly in development work, under special environmental circumstances. Gas problems may be reduced or eliminated by predrainage of gas ....:. rarely successful from the working seam - usually undertaken from adjoining seams prior to escape of gas released by caving. The ideal solution - general predrainage of gas to the surface from measures prior to mining - has yet to be accomplished. • In the planning of gassy mines it is possible to make an assessment of gas contained in the seams and to estimate what proportion will be released into the mine air, but emission of gas into mine workings is never steady and at present there is no better planning criterion than experience at the mine next door!"

Jan 1, 1973

Shafts are the most important workings in the underground mines. Their technical state to a large extent determines the safety and efficiency of mining operations. However, in many cases periodically performed inspections show unsatisfactory technical state of the shaft lining (local defects, cracks, cavities, losses of the outer surface of the lining or, in case of the bricks, losses of the masonry). The most common cause of these types of damage is progressive deterioration of the lining material, impact of aggressive mine waters, impact of mining operations, deformation of the lining due to the rock mass saturation, seismic activity or periodic freezing of the lining in the upper part of a shaft. The paper presents legal requirements associated with the use of mine shafts in Polish coal mines as well as the ways and range of their control. Furthermore, examples of typical damage to shaft lining and ways to repair it, such as additional bolting, filling cavities or a wire mesh and shotcrete installation, are shown. In the final part, the paper presents a short example of a shaft, in which damage to the lining was one of the main causes of the shaft's failure. Due to the damage to the shaft lining, at the depth of approx. 65.0 m, the shaft was spontaneously filled with overburdened soil material. It resulted in a large crater to come to the surface, which, in turn, caused damage to the buildings and facilities present in the impact zone. On the surface the diameter of the crater was approx. 60.0 m, its depth approx. 11 m and the estimated volume was of about 30,000 m³. The disaster also caused disturbance in the ventilation of two neighbouring mines and the increase in methane hazard. Given the size of the crater, the measures to eliminate consequences of the catastrophe were undertaken in several stages.

Aug 1, 2013

By B. R. Hart, S. S. Dimov, J. Fournier

Carbonaceous matter (c-matter) in sulphide ores can adversely affect the process of gold recovery during cyanidation due to its ability to adsorb, or preg-rob, gold from a cyanide leach solution. This paper describes a standardized procedure for characterization of c-matter in an ore sample providing detailed information on its composition, maturity and preg-robbing capacity. The procedure utilizes the following complementary analytical techniques in conjunction with several chemical tests and assays: SEM/EDX Raman spectroscopy and TOF-SIMS. Results of the test can be used as a predictive tool to estimate the impact the c-matter will have on the gold recovery process. A comparison between predicted preg-robbing behaviour and cyanidation test results are presented.

Jan 1, 2011

By R. Baker

A novel electrochemical half-cell and corresponding working electrode were designed to evaluate the electro-catalytic activities of catalysts in an environment close to that of an operating proton exchange or polymer electrolyte fuel cell (PEMFC). Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) techniques were employed using the novel cell to characterize various methanol electro-oxidation parameters that contribute to the overall reaction on a fuel cell anode. The effect of temperature on methanol oxidation kinetics was examined in the potential range of 0.31 to 0.65V (vs. NHE). The data was collected in the temperature range of 20 to 80°C. Based on the experimental analysis and literature data, an equivalent circuit model (ECM) for methanol oxidation was proposed and was used to fit the EIS experimental data. The experimental data and ECM electrochemical data was used to extract electrochemical kinetic parameters for methanol oxidation such as the exchange current density, Tafel slope, and energy of activation for the reaction. Kinetic data, especially at different temperatures, is very limited in the literature.

Jan 1, 2005

By D. A. Beattie

Talc is a commonly encountered gangue mineral in metal sulfide flotation. Talc is naturally hydrophobic, resulting in high recoveries if polymeric depressants are not used to specifically reject this MgO containing mineral. We have studied the adsorption of a selection of polymers onto talc using a variety of techniques. Adsorption isotherms have been determined using ex situ depletion techniques and in situ ATR-FTIR spectroscopy has been used to determine adsorption kinetics. Adsorbed layer thicknesses have been determined for the polymers on cleaved talc surfaces using the AFM. The effect of the adsorbed polymer layer on the properties of the talc surface has been quantified through contact angle measurements and single mineral flotation tests. Distinct correlations are observed between the adsorbed layer properties and the flotation performance of the polymers. These observations are discussed with reference to the bubble-particle attachment process and the molecular structure of the polymers.

Jan 1, 2006

By A. J. DeArdo

Linepipe steels have come a long way in the past forty years. In fact, modern, high strength steels for large diameter linepipe applications represent one of the seminal accomplishments in metallurgy of the past half-century. The synergy of advanced steelmaking, alloy design including microalloying, hot rolling, and interrupted accelerated cooling has led to the marvelous steels being used today. The drive for higher performance pipelines has been motivated by the energy sector of our global economy who wanted both higher throughput capacity, i.e., larger diameters and higher pressures, and lower material cost, i.e., relatively thinner gauge wall thicknesses. These requirements led to new steels with higher strengths, better toughness and improved weldability. The goal of this paper is to trace the evolution of linepipe steels from the X60 grades of the small diameter pipelines of the 1960s to the (X80 - X120) grades used in the large diameter pipelines of today. The metallurgical triumphs permitting this success story, e.g., clean steel practices, controlled rolling, microalloying with Nb, and using IAC to obtain low temperature transformation products, will be highlighted and discussed.

Jan 1, 2005

By Ian S. Leslie

Seismic monitoring systems for mining operations are being utilized more than ever before in the characterization of rock mass response to underground and open pit mining. This paper provides a review of the use of microseismic monitoring for rock mechanics applications at mines throughout the world. Some practical considerations for the installation of these systems are presented along with techniques for optimizing seismic array coverage. Case studies and installation examples are also provided. Recent applications of advanced seismic analysis techniques are discussed including the determination of event mechanisms, mapping of maximum peak particle velocity (PPV) and seismic hazard fields, and the use of source parameter data for large event re-entry protocol.

Jun 1, 2012

By M. L. Wacker

"Cigar Lake high-grade uranium mine in Saskatchewan is operating after 25 years of test mining, construction, and mine flood remediation. Factors include ground stability, groundwater control, radiation exposure, and ore handling. A 10 year test program resulted in validating “jet boring”, a non-entry mining method involving artificially freezing the orebody and surrounding rock; tunnelling to develop access crosscuts below the orebody; installing cased pilot holes through ore; extracting ore using rotating high-pressure water jets within pilot holes; and cavity concrete backfilling. Ore slurry is prepared underground, pumped to surface, and trucked to McClean Lake mill for processing to uranium concentrate.RÉSUMÉ Après 25 années d’essais sur les méthodes minières, de construction et d’assainissement suivant les inondations à la mine, l’exploitation de minerai à haute teneur en uranium Cigar Lake, localisée dans la province de la Saskatchewan, est opérationnelle. Les principales difficultés concernent la stabilité du terrain, le contrôle des eaux souterraines, l’exposition aux rayonnements et la manutention du minerai. Un programme d’essai de 10 ans a abouti à la validation du « forage à érosion », une méthode minière qui consiste à congeler artificiellement le corps minéralisé et les roches environnantes ; à creuser des tunnels pour développer des travers-bancs d’accès en dessous du corps minéralisé ; à installer des puits de fondation pilotes à travers le minerai ; à extraire le minerai à l’aide de jets d’eau à haute pression dans les puits pilotes ; et à remblayer les cavités avec du béton. La boue de minerai est préparée sous terre, pompée vers la surface puis transportée par camion jusqu’à l’usine de concentration de McClean Lake pour le traitement afin d’obtenir du concentré d’uranium.INTRODUCTIONThe Cigar Lake deposit is in northern Saskatchewan, 660 km north of Saskatoon, Saskatchewan, Canada, at the east edge of the Athabasca basin (Figure 1; Bishop, Mainville, & Yesnik, 2016). The operation is jointly owned by Cameco Corporation, AREVA Resources Canada Inc., Idemitsu Canada Resources Ltd., and TEPCO Resources Inc. Cameco has been the operator of Cigar Lake since January 2002. The discovery hole was drilled in 1981. Commercial production was declared in May 2015 and the Phase 1 operation will have a mine life of 15 years."

Jan 1, 2017

By Luis R. Fonseca, C. Raimat, C. Wendeler, A. Sanz

"Rockfall barriers are widely known as proven efficiency element to protect infrastructure by catching the rock blocks in the falling direction and absorbing the energy generated by them.It’s common in the project design phase and during installation, fix rockfall barriers for catch a high percentage of the falling blocks and in many cases consider as valid the solution when the barrier can capture all of them. However, in many cases it’s possible to consider the use of these protections, simply to guarantee a secure shed for the traffic and intercept simply the blocks that theoretically hit the road surface.The results of the high-energy rockfall protection barriers type GBE which protect GC-200 road in Las Palmas de Gran Canaria are shown in this paper.The topographic data should be especially detailed observed and even more if you want to apply the technique of ""shadow zone"" with a flexible gallery system. It should be drawn from detailed topographic maps and drawings (photogrammetric restitution) to the scales 1/1000, 1/500, or 1/200; and it is important not to ignore the presence of vertical cuts, tracks, small slopes that modify the trajectories (trampoline effect, hard points that favor the rebounds) and which are not always presented in the drawings.The ""shadow zone"" is defined as the protected area, located at a lower elevation to the line created by the rockfall barrier to except of trajectories of rocks and free from the influence of the deflection of the system under the maximum energy level for which it was designed (MEL)."

Jan 1, 2015

By A. J. MacEachen

"LIKE ALL OTHER NOVA SCOTIANS, I have been thrilled during the past few years with the growing evidence that substantial reserves of oil and gas are being discovered off the Atlantic coast of Canada. There are those in this province who believe that large-scale commercial production is just around the corner, and that when it starts Nova Scotia will begin to float on a sea of royalties. These overly optimistic people, of whom I am not one, are convinced that with the first barrel of oil shipped to market, Nova Scotia can forget its financial problems while its people take on the luxurious lifestyle of the shieks of Kuwait or Saudi Arabia. You and I know, however, that even though offshore oil and gas may turn out to be the greatest gift nature has ever bestowed on Eastern Canada, it may take some considerable time before the reserves can be accurately assessed, before the industry can become fully operational, and before the benefits of production can be translated into royalties and tax revenue, improved public services, new industrial facilities and more jobs. While it is premature for the ordinary Nova Scotian to take on the habit of buying expensive cigars and lighting them with ten-dollar bills, it is not too early for him to insist that governments and industry plan intensively and well for the beneficial exploitation of undersea resources."

Jan 1, 1973

By Chas. L. Emery

"The laws of rock mechanics apply equally well to all rock structures, and open pits are not exceptions. The concepts and some arguments about the emphasis to be placed on various aspects of open-pit design are discussed in this article.RocksROCK can be described as a granular material consisting of grains and glue. The grains may be fragments of other rocks or polycrystalline aggregates. The glue may be ferruginous, calcareous, argillaceous, siliceous or other material connecting the grains. In a crystal intergrowth, the outer layers of the crystals in contact with each other may be considered to act as a glue. Water may be a glue in clay or a grain in a crystal structure. Air and other fluids or gases are grains if they occupy spaces in a granular mass. Such grains are functional either chemically or mechanically or both."

Jan 1, 1966

By N. Saracoglu, R. H. Wallis, J. E. Betz, F. L. Jagodits, B. R. Krause

"Geophysical test surveys were conducted with various methods (EM, lP, gravity and magnetic) over the McClean uranium deposits of the Canadian Oxy- lnco Joint Venture. The result s were assessed to judge the contribution each method might make toward further discoveries of graphite-associated uranium occurrences.The best drill targets have proven to be discontinuities in graphitic conductors and locations where the tatter are intersected by fracture zones in the Athabasca. The tests demonstrated that the preferred combination of geophysical survey s is horizontal loop EM to locate graphitic conductors in the basement and VLF-EM to locate the fractures.IntroductionThe discoveries of the McClean North and South uranium deposit s (Fig. 1) are essentially geophysical successes resulting from drilling MaxMin delineations of INPUT airborne electromagnetic responses (Saracoglu et al., 1983). After the initial discovery in 1979, various geophysical methods, techniques and instruments were employed to test their effectiveness in this environment and to guide exploration for other deposit s of a similar nature in the remainder of the 260 km2 property.The McClean uranium deposits lie below 150 m to 180 m of overburden and Athabasca Group. Radioactive signatures might be expected; however, the Athabasca Group acts as a barrier to radioactive emanations. Fortunately, the uranium mineralization is associated with graphite in the crystalline basement. Prior drilling of ground electromagnetic anomalies confirmed that EM surveys could locate and out line basement graphitic conductors. However, as there were many anomalies, most of which could not reasonably be expected to be associated with uranium , there was need to identify additional parameters, related to mineralization, which could be detected geophysically and used to narrow the search."

Jan 1, 1986

By Ken J. Brouwer

Stillwater Mining Company commenced construction and development of the East Boulder underground mine in 1998. This new PGM mine is situated adjacent to the East Boulder River approximately 35 miles south of Big Timber, Montana. Project planning and development incorporated detailed collaboration between the regulatory agencies, concerned citizens and mine personnel. A unique ?good neighbour agreement? was established with a local environmental group who have become actively involved in the review of ongoing site development and the implementation of environmental and compliance monitoring. Environmental management systems allow for integrated management of tailings, waste rock and water in order to minimize surface disturbances and to prevent adverse impacts to the East Boulder River. Long-term site development plans contemplate implementation of comingled waste rock and paste tailings. Water management capabilities allow biological treatment of all excess mine water in order to reduce nitrogen loadings prior to land application disposal by means of spray evaporation, snow making and land application. The comprehensive waste and water management plans have also been integrated with staged mine development and interim reclamation requirements.

May 1, 2002

By H. J. Rowley

THERE are many varieties of limestone, but for the general purposes of the pulp and paper industry, two classifications are sufficient: (1) High-calcium stone, which should be quite free from impurities and contain not less then 90 per cent calcium carbonate. (2) High-magnesium stone, containing not less than 25 per cent of magnesium carbonate. Before proceeding with detail on the use of limestone and lime in the industry, a few words regarding the pulp products made in Canada are desirable. By far the largest tonnage is made by grinding spruce and balsam logs on rotating sandstones or on artificial abrasive stones of the Norton or Carborundum types. This mechanical or groundwood pulp finds its largest use in the production of newsprint paper, of which it comprises about 80 per cent of the total fibrous substance employed-the remaining 20 per cent being unbleached sulphite pulp. No limestone or lime is directly employed in making groundwood pulp, as contrasted with the chemically prepared pulps, all of which require one or the other form of the base for their processing. Sulphite pulps comprise the next largest tonnage group. They are produced by boiling, under pressure and at elevated temperatures, spruce and balsam wood in chip form in solutions of bisulphites and sulphurous acid. The usual bisulphites employed are those of calcium and magnesium. Sodium, potassium, and ammonium bisulphites give progressively better pulps, but to date, in the absence of efficient recovery methods, cost has precluded their use.

Jan 1, 1939

By W. G. Deeks

CANADIANS are world leaders in marketing metal and mineral products. Noranda Sales Corporation Ltd. is an international metal and mineral product marketing company operating from Toronto and London, England, where it operates a wholly owned sales subsidiary and is a 50% partner in Rudolf Wolff and Company Ltd., a charter member and the largest metal broker on the London Metal Exchange. Noranda Sales employs 97 people, of whom 52 are university trained and professionally competent in international resource product marketing. We market for 19 companies or divisions in the Noranda Group and 39 companies for whom we act as agent, consultant and purchaser of resource production. Our business in 1976 was 1.5 billion dollars carried out in 45 countries and covering 24 products and materials. Today, ownership of most of the mining industry in Canada has transferred back to Canadians, and this is said with the knowledge that a significant part of the Canadian industry has been Canadian owned and managed from its very early days. Noranda Mines Limited is such an example. It was born in 1922 as the result of a copper-gold showing at Noranda, Quebec, discovered by Ed Horne, a prospector, financed with a grubstake by a syndicate mainly composed of New York businessmen. Shortly after the discovery, when the shares of the company had risen, the syndicate was sold to Canadian interests and, since that time, Noranda has been dominantly Canadian owned and certainly Canadian managed. Today, over 90% of Noranda's shareholders are Canadian, who hold an equivalent percentage of the stock.

Jan 1, 1977