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By M. Dupuis

It has been previously demonstrated [1,2] that using selective collector bar rodding has a big impact on the uniformity of the current density at the top surface of the cathode block and hence on the intensity of the horizontal current in the metal pad, The present study investigates the impact of using selective collector bar rodding on the MHD stability of a 500 kA aluminium electrolysis cell, For this purpose the recently developed MHD package for the aluminium reduction cell time dependent behavior is used.

Jan 1, 2005

"The Crescent, DM, and Pothook zones are copper-gold porphyry deposits which formed in association with alkalic intrusions of the early Jurassic Iron Mask batholith. The characteristics of the Crescent and DM deposits are nearly identical. Both formed along the contact between the Cherry Creek monzodiorite and Pothook diorite phases of the batholith. Permeable intrusion breccias along the contact concentrated the flow of hydrothermal fluids. Early, pre-ore alteration is represented by pervasive, sulphide-barren potassium metasomatism. The precipitation of copper-gold ore occurred during subsequent fracture-controlled potassic alteration, and is most strongly developed in chlorite-sulphide veins and their alteration envelopes. A central zone of potassic alteration is surrounded by a propylitic, pyritic halo in both deposits. The DM zone is unique among alkalic porphyry deposits in its high abundance of quartz-sulphide veins.The Pothook deposit formed at the westernmost contact of the Iron Mask batholith with enclosing Nicola Group volcanic rocks. Pervasive potassium metasomatism, similar in style to that at Crescent and DM, is associated with intrusion of the Cherry Creek monzonite. Pervasive and fracture-controlled albitic alteration is associated with intrusion of the Sugarloaf diorite and introduced minor copper-gold mineralization. Most of the copper-gold mineralization was introduced during formation of veins and breccia matrices dominated by magnetite/hematite and sulphide. Late-stage chlorite veining may have remobilized or introduced additional gold mineralization.Copper and gold assays in the Crescent deposit are well-correlated and have a nearly constant Cu:Au ratio, suggesting that the metals coprecipitated during a single hydrothermal event. In the Pothook deposit, copper and gold do not correlate closely, lack spatial correspondence, and suggest that transport and/or deposition of the two metals were not identically controlled and that they may have been introduced at different times by separate hydrothermal events."

Jan 1, 1995

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

By J. Aiello

"Introduction Byron Creek Collieries Limited Corbin mine is located in southeastern British Columbia approximately 180 air kilometres southwest of Calgary (Fig. I), twenty four kilometres south of Highway No. 3 via a newly constructed provincial road (Fig. 2). The development of the area began July 30, 1905, when D.C. Corbin, a prominent businessman from the northwestern U.S., and his associate E.J. Roberts first visited the site of Coal Mountain on horseback. Coal was in great demand by railways and other industrial users, so the Corbin Coal and Coke Co., after acquiring 6,000 hectares of land in the area, began to develop a mine. Mr. Roberts was responsible for the construction of the 22-kilometre rail spur, the Eastern British Columbia Railway, which joined the mine to the CPR main line at the McGillivray Loop. Rail access to the mine and its developing community, Corbin, B.C., was completed in September 1908, the same year that the first underground mine began production. The Corbin Coal and Coke Co. operated six mines on Coal Mountain (Fig. 3) and production from 1908 to 1930 inclusive totalled 2,120,800 tonnes. This production was allocated to the mines as follows:"

Jan 1, 1985

By M. E. Hurst

SINCE 1934 there has been a marked revival of interest in the Porcupine district, especially in the eastern portion of the area, where exploration on the property of Pamour Gold Mines has indicated the presence of extensive gold-bearing deposits. Owing to the prevalence of overburden and the limited amount of exploratory work that has been done, little information is available as yet concerning the distribution and structural relationships of the rocks in the area to the east of Porcupine lake. In order to throw some light on the structural conditions in this section, a brief discussion of the sequence and character of the formations in the better known, producing section of the camp has been included. It should be emphasized that this paper is a preliminary study and that, consequently, the conclusions expressed should not be regarded as final. The writer wishes to acknowledge his indebtedness to P. C. Benedict, whose study of the geological relationships on the Foley-O'Brien property has made possible a fuller understanding of the structure in the central portion of the area. The writer also wishes to express his appreciation of the information and facilities placed at his disposal by R. M. Macaulay and C. D. Stevenson, of Pamour Gold Mines, and by A. Bell, of Noranda Mines, Limited.

Jan 1, 1936

By David Runnels

The Mount Wright iron are mine and upgrading plant were brought on line in the fall of 1975. The mine is located near the Quebec - Labrador border some six hundred miles northeast of Montreal. This paper describes the crushing, grinding and concentrating facilities at Mount Wright, and some design: criteria used in equipment selection and flow sheet design. Also mentioned are some "asbuilt" modifications. A brief description of the over-all flowsheet is also included. Introduction IN SEPTEMBER 1970, the Quebec Cartier Mining Company started development of the Mount Wright iron ore mine. The estimated are reserve is in excess of 1,000,000 ,000 long tons of concentrates, with an average crude are grade of 31.5% Fe. The run-of-mine ore is crushed, ground and concentrated to a product having 66% Fe and 5% silica at an annual concentrate production r ate of 18.4 million long tons. The daily production rate of over 50,000 long tons of concentrate necessitates a daily mine output of approximately 250,000 long tons of material, of which 50% is waste.

Jan 1, 1977

By G. D. Bysouth, G. Y. Wong

"The Endako molybdenum deposit is located 160 km west of Prince George, British Columbia. It occurs within the main body of the Francois Lake Intrusions, a composite batholith consisting of early, middle and late intrusive phases. The ore deposit is confined to Endako Quartz Monzonite, a middle phase intrusion, which is bound on the north by Carey Alaskite and on the south by Francois Granite, both late stage intrusions. In the mine aretz, the Endako Quartz Monzonite has been intruded by pre-ore dikes of quartzfeldspar porphyry and porphyritic granite, and by post-ore dikesof basalt.The Endako deposit forms a west-northwest trending body that has a strike length of 3360 m and an apparent width of 370 m. It consists of four structurally distinct zones: Endako East, Endako West, Denak East and Denak West. Principal sulphide minerals of the deposit are pyrite and molybdenite, accompanied by magnetite and minor chalcopyrite. Galena, associated with wulfenite and bismuthinite, occurs in some ores of Endako West and Denak as minute inclusions in molybdenite. The sulphides and associated minerals are hosted by quartz veins which occur principally in vein systems. Hydrothermal alteration accompanying ore mineralization has pervasively kaolinized the quartz monzonite host rock, and has locally produced K-feldspar and quartz-sericite-pyrite envelopes on quartz veins.Primary structural controls of the deposit are southwesterly dipping vein systems which strike 110° in the Endako zones, 110° to 130° in Denak East and 170° in Denak West. Secondary structural controls are northeasterly striking vein systems that dip northwesterly in Endako East and southeasterly in Denak. Domal uplift accompanying the rise of latest stage magma is considered to have caused intense dilatant deformation along older west-northwest trending shear zones, producing an elongated structural host for ore deposition."

Jan 1, 1995

By Lawrence Devon Smith

The selection of the production rate is one of the most crucial decisions to be made in the development of a mineral property. However, it is not uncommon for the production rate to be decided arbitrarily, before any technical evaluations begin, and it is often not reconsidered when better data becomes available. A number of methods are used in the mineral industry to select the production rate for a project. There is general agreement that the size of the ore reserve has a strong influence on this decision, but what other factors are involved? Is there a way to identify an optimum rate? This paper examines the factors that influence the selection of a production rate from the perspective of project economics. The NPV maximum value should be viewed as a “failure” point. The “two times capital” maximum is proposed as a lower limit. A practical check is suggested to confirm that a selected rate is in an optimum range. Production rate assumptions are much more likely to be reviewed for marginal projects, but they should also be reviewed for viable projects.

Jan 1, 1997

By E. R. Landry

This paper reviews the current state of electric furnace technology, with emphasis on some of the more recent developments. A large section of the paper is devoted to the use of increasingly high power inputs by arc furnace operators. Operating practices are then covered, including some of the newer techniques which have been tried.

Jan 1, 1967

By G. F. Miller

ONLY IN THE Province of Saskatchewan is natural sodium sulphate found in Canada in amounts large enough to make recovery economically sound. Geologists have estimated that the numerous deposits within the Province contain upwards of 200 million tons of Glauber's salt. There are twenty-one deposits in the Province which contain 500,-000 or more tons and about two dozen with lesser amounts. The first recorded production of sodium sulphate in Saskatchewan was in 1918. The company concerned, and others that attempted to develop the industry in its early stages, were unsuccessful. Their failures were caused by two main factors -lack of knowledge of efficient operating methods and the unstable market situation for the finished product. Today, the situation is changed in both respects and the product, commonly referred to as 'saltcake", is a very important chemical requirement of many industries throughout the world. Before proceeding with remarks on manufacturing methods it should be stated that, although this is a general paper on the manufacturing methods and end uses of the saltcake produced in the Province, the writer is, of course, more familiar with the plants operated by Saskatchewan Minerals than with other operations and perhaps may be excused for dealing more particularly with the plants of that Compa11y.

Jan 1, 1958

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 R. D. Brown

"When elephants fight, it's the grass that gets trampled". It is becoming increasingly evident that the federal and provincial governments are awakening to the fact that their vigorous scramble for a "fair share" of mineral revenues which kicked off in 1974 has done considerable harm to the Canadian mining industry. Recent public statements made by government officials, particularly at the recently held annual convention of the Prospectors and Developers Association, would indicate that there is a general consensus in the government sector that changes must be made to the mining tax system. However, there is no evidence as yet that there is any agreement among the various governments as to what form these changes should take , who should make them , or when. It would seem to be worthwhile at this time to reflect on where the Canadian mining industry has been vis-a-vis taxes and "where it is at ". This article is based on a recent address given by R. D. Brown, of Price Waterhouse & Co., Toronto, at the annual convention of the American Institute of Mining, Metallurgical and Petroleum Engineers in Denver , Colorado.

Jan 1, 1978

By James A. Robertson

"This paper is the result of a continuing investigation begun in 1953 by government geologists and mining companies. Previous work is reviewed and the development of several stratigraphic nomenclatures and correlation schemes is traced, culminating with the interim report of the Federal-Provincial Committee on Huronian Stratigraphy formed in 1966.The stratigraphy, structure and correlation of the Huronian rocks of the Blind River area and the region between Sault Ste. Marie and Sudbury are reviewed. The area is underlain by three Precambrian units: (1) the Archean greenstones and granites, (2) the Huronian sedimentary and volcanic rocks and (3) the post-Huronian intrusive rocks. The Huronian rocks, largely quartzite and conglomerate with greywackes, argillites and carbonates, were laid down in shallow water transgressing over the eroded Archean basement. Thickness and facies changes indicate a northwesterly source, northerly overlap and deposition controlled by basement topography. Polymictic conglomerates, occurring at least at three horizons, represent tillites and are associated with varvites with dropped clasts. These are best developed in the Gowganda formation, which varies from a continental glacial environment in the north to a marine glacial environment in the southeast.There were at least three phases of post-Huronian igneous activity, probably related to several periods or phases of late Precambrian deformation and metamorphism: (1) sills of Nipissing diabase and rather younger diabase dikes; (2) the Cutler Granite and Croker Island Complex; and (3) dikes of Keweenawan olivine diabase.Copper mineralization is associated with the Nipissing diabase. The uranium ores are found in pyritic quartz-pebble conglomerate near the Huronian Archean unconformity, particularly in ancient valleys; they are considered to be placer deposits modified by later events. Uranium production from the Blind River camp to the end of 1966 was 128,160,096 pounds U308 valued at $1,203,840,848 derived from 56,077,179 tons of ore grading 0.11 per cent U308.Within the Blind River and adjacent areas, future discoveries will probably be the result of costly systematic deep-drilling programs accompanied by detailed geologic studies of the type carried out by oil companies and probably computer-oriented."

Jan 1, 1969

By I. R. Jonasson, R. W. Boyle

"Current interest in the distribution of mercury in the natural environment comes from quite different, though not unrelated, sources. Mercury has long been an important metal in many industries and has, therefore, been much sought after by mining interests. The presence of mercury traces in the various media of the natural environment, namely soil, rock, air, water and vegetation, is exploited by geochemists not only to find mercury and polymetallic ore deposits, but also to find most other types of economic metal mineralization. More recently, however, mercury has caught the attention of health authorities and environmental scientists who are becoming increasingly concerned over the hazards of mercury wastes and the danger these present to the environment and to man. It is now apparent that the trace quantities of mercury, considered so important and helpful to exploration geologists, can be concentrated in the biosphere to such levels as to present considerable problems for ecologists. This article summarizes most of the available data on mercury contents in materials of geological interest and presents average normal values for rocks, ores, minerals, soils, sediments, waters and plants. The geoch.emical cycle for mercury in nature is presented and the mechanisms of mercury migration around the cycle are discussed."

Jan 1, 1972

By M. A. F. Fedikow, D. A. Baldwin, C. Taylor

The Agassiz Metallotect and the Johnson Shear Zone represent two metallogenetic fea tures located within the northern and outhern belts, respectively. of the Aphebian-aged Lynn Lake greenstone belt in northern Manitoba . Numerous gold occu rrences are associated with these two regional features . The tratabound Agas iz Au-Ag deposit with 2.9 million tonnes of 5.2 g/tonne Au and 11.8 g/tonne Ag. occurs within the Agassiz Metallotect. The stratigraphic sequence characterizing the Agassiz Metallotect comprises interlayered ox ide. silicate and sulphide facies iron formations, biotite-rich and siliceous siltstones. and a high Mg- i-Cr basaltic rock that ha previou ly been identified as tholei itic picrite. These rocks can be traced in outcrop and by their INPUT and gradiometric signature for 65 km. The Johnson Shear Zone is an ill-defined 35 km long zone of strucwral disruption that crosscuts volcanic. sedimentary and intrusive rocks and contains numerous vein-type gold occurrences. Both of these metallotects are characterized by their low level of exploration activity and as a result offer excellent residual exploration potential. Rock, basal till and vegetation geochemical techniques applied in the vicinity of the Agassiz deposit indicate the presence of trace element dispersion halos associated with the mineralization. The halos define an exploration target larger than the mineralized zone. Gold occurrences within the two metallotects are described with emphasis on the Agassiz Au-Ag deposit . A wide range of gold occurrence-types is documented including syngencticstratabound , epigenetic-replacement and epigenetic-quartz vein .

Jan 1, 1986

By Christopher Boys

"Abstract -Many water inflows in Saskatchewan potash mines are linked to salt anomalies. Potash ore and three anomalies in the PCS Cory potash mine in the Patience Lake Member of the Prairie Evaporite Formation were studied to understand the processes involved in their formation. Another goal was to find geological indicators of the proximity of anomalies. A geological model that relates the potash to the salt anomalies has been developed.Up to five post-burial facies may be recognized . These range from carbonate-mud collapse breccias to bedded sylvinite, and probably result from post-burial leaching. ln this model, the same fluids that caused widespread recrystallization and possibly enrichment of the potash salts, started by dis­ solving huge cavities in the evaporites . The effects of the leaching were highly variable, indicated by selectively preserved delicate laminae and chevron textures, to deformed and totally dissolved salt beds . ln at least two major events, Late Devonian and Cretaceous, collapse structures may have acted as conduits for overlying formation waters to cause pervasive leaching and recrystallization of the Prairie Evaporite Formation .Geological indicators of the proximity of an anomaly may include: a change in Insoluble seam color from greenish-gray to mottled brown and greenish-gray, unusual local increases in ore grade, large patches (e.g., >200 cm2) of sylvite-poor potash crosscutting units near the top of the ore zone, and drops in topography >10 m of the marker seams. Anhydrite was more common in an anomaly than in ore. The local abundance of anhydrite in ore may indicate the proximity of some salt anomalies.Once an anomaly has been encountered, indicators of a major collapse feature may include: stretched clay seams, folded beds, small collapse features (1 m to 20 m), numerous washouts, or split clay seams with injected salt. Any number, or none, of these indicators may be found close to a major collapse feature."

Jan 1, 1993

By D. M. Watson

Mineral discoveries and subsequent extraction have led to the establishment of many small communities, some major towns and a few cities . In Canada, such developments have essentially occurred without benefit of long-range regional or local planning. In the past, this was not a cause for concern. Now, however, rising expectations and reorientation of social values have placed increasing responsibility on government and industry to ensure the long-term viability of communities and regions. Such responsibility means large investments by government in infrastructure and by industry in extractive and processing plants. Uncertainty in the interpretation of ore reserve estimates becomes a critical factor. The traditional methods of reporting reserves - "proven", "probable" , "possible" - may be useful in individual mine production planning, but they are inadequate for planning industrial and public infrastructure, The need for a better information base is critical, with clear and precise definitions of what is being reported, but we are a long way from achieving it. The challenge is therefore to develop a closer professional relationship between government and industry and to tie mineral development to long-range regional strategies.

Jan 1, 1977

By A. S. Baillie

THE subject of taxes appears to engage our attention altogether too lightly. At least it would seem that, notwithstanding the increase in the cost of government, and its concomitant increased taxation, little constructive work is being done with a view to solving the problem of increased taxes. I believe that the inattention of the public generally to the subject of increased taxation is due largely to the fact that shareholders are not advised of the amount of taxes paid by industry. Were companies to advise their shareholders the amount of monies paid or payable out of each year's earnings for taxes in one form or another, and were such amounts compared with the amounts available for distribution to shareholders, the effect would be a general demand for more equitable taxation methods. While I am not unmindful of the burdens and inequities in taxation confronting industry generally, I believe that the mining industry in this Province does not fully appreciate the burden represented by the costs of taxation. My reason for this belief is based partly upon1the fact that no serious effort has so far been made to devise some means By which the mining industry in British Columbia might protect itself against the ever-increasing burden of taxation. In addition to this fact the widely diverse nature of mining in British Columbia makes the accumulation of comparable data a problem which, so far as I can ascertain, has never been attempted in a manner which would be authoritative. It should not be necessary to cite the effects of this burden upon any one mining company or upon any branch of the mining industry, such as coal mining, placer mining, base-metal mining, or the precious-metal mines. In my opinion, the operation of our mines by large corporations is conducive to the payment of taxes with much less protest than would be the case were the taxes being taken out of the earnings of just a few partners or a very few shareholders. We appear to be too unmindful of the taxes, paid by mining companies, of a kind that are not so prominently brought to our attention as are the taxes which are calculated upon the taxable income of the company at the end of its fiscal year. British Columbian mining companies pay many other taxes besides those which are calculated upon taxable income. Among these are school taxes, property taxes, gasoline taxes, mineral taxes, coal royalty, to say nothing of fuel-oil tax, sales tax, and excise taxes.

Jan 1, 1935

By David C. Cook

The milling complex, situated just east of the Cassiar townsite, receives raw ore from the tramline and processes it into 105,000 tons per year of milled asbestos fibre. The ore is passed through a concentrator, where a barren rock fraction is removed. The concentrated ore, representing 70% of the feed, is dried, stored and then milled into nine separate fibre classifications. The finished product is packaged into 100-lb bags and loaded into trucks in one-ton units. New air-handling facilities were added in 1977to provide additional air for environmental control.

Jan 1, 1978

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