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By M. A. Upham

"MINING is Canada's second largest basic industry, producing material with a gross value of 2.5 billion dollars, led only by agriculture with 2.9 billion dollars. It pro-vides employment, directly and in-directly, for three quarters of a million people. Since the Second War, the value of mineral production in Canada has tripled. Economists forecast that over the next 15 years its value will triple again. Canada is a basic and leading supplier of nickel, iron, copper, zinc, lead and uranium. It is also a major oil producer, leads the world in the production of asbestos and in five years will be the leading producer of potash, a basic constituent of fertilizer.It can be seen that Canada's wealth and economic progress lies in being a primary producer of economic minerals and in building secondary industries to manufacture finished products from these raw materials. Canada's future in the field of mineral production looks bright, with our resources just starting to be tapped. Outside of the large expanse of Soviet Russia, we are by far the world's most fertile mineral exploration area."

Jan 1, 1967

By J. H. H. Chamberlin

"In the Introduction the author briefly discusses the company history as it relates to the development of its contracts with the Japanese steel mills. The main part of the text describes how Coleman Collieries Limited approached the problem of mining coal profitably in thick, steeply inclined seams. For many years a basic room-andpillar system was worked by conventional methods. Main roadways were driven on strike across the mineable area. These roadways acted as haulage routes for coal, materials and men. Rooms were developed to the rise of the main haulage route by pairs of men using air-operated hand picks. As these rooms advanced the miners would lay and extend a sheetiron chute down which mined coal would gravitate to a controlled loading point, where it was loaded into trains of mine cars. Connecting roadways or ""OFFS"" were driven at predetermined intervals between adjacent rooms, forming pil1ars or blocks. Extraction of the blocks followed on a line conducive to good strata control some distance behind the developing rooms. A need for higher productivity, expansion of the operations and a scarcity of qualified miners resulted in the company deciding to mechanize its underground mines. Joy 6 CM continuous miners and 10 SC shuttle cars were selected as being machines that could reasonably negotiate the problems associated with the pitching seam. The equipment, nonetheless, has definite limitations and Coleman therefore developed a modified version of the room-and-pi11ar system such that the miners and cars could work on cross pitch. In the area described, main roadways were driven to the rise on an average gradient of 12 degrees. Panels, which consisted of two parallel roads with interconnecting cross-cuts, were then developed on strike to a boundary point. Blocks formed in the development of the panels were subsequently extracted on retreat. Problems associated with each phase of the operation are thoroughly discussed, together with roadway support methods and equipment used for the conveyance of coal and materials."

Jan 1, 1972

By C. A. Sutherland

"Smelting of copper-gold ore from nearby Rossland mines started at Trail in the 1890s. As ore from the Rossland mines became exhausted, lead smelting of hand-sorted galena ore from other British Columbia mines was initiated. With the development of flotation technology for the separation of lead, zinc, and iron sulphides in the first two decades of this century, the large Sullivan orebody at Kimberley, British Columbia, became the f oundation for the growth of a major zinc and lead smelter at Trail. Lead smelting began in 1901, electrolytic zinc in 1916, and by 1984, the Trail metallurgical complex had produced 10 million tons of each metal. Its present capacity is 270000 tonnes per year of zinc and 110 000 tonnes/year of lead.This paper reviews the history of technological changes in the Trail production plants, emphasizing the zinc plant modernization program started in the 1970s, and also the planned introduction of the QSL oxygen lead smelting process in the late 1980s. Lead modernization will increase production capacity to a maximum of 160000 tonnes per year.IntroductionCopper-gold ore was discovered at Rossland, British Columbia, in the year 1890, starting a mining industry that was to last over three decade s. Selected ore was at first transported at high cost to distant U.S. smelters, so there naturally followed a decision to construct a small copper smelter to process the local ore to matte. It was built in 1896 at the mouth of Trail Creek on the Columbia River, about 10 km from Rossland. This little smelter was to develop and diversify in the next 90 years into the world 's largest lead-zinc producer).The mining boom that occurred in the northwestern United States and southeastern British Columbia in the period of 1890 to 1910 saw the brief operation of many small local smelters. The only one to survive was the smelter at Trail. The circumstances that permitted its continued life and subsequent growth, form a fascinating history of business deals, litigation, andsteady technical progress.Early investment in local railway transportation and options by F.A. Heinze, the smelter' s founder, attracted the attention of the Canadian Pacific Railway Company, which purchased Heinze' s assets in 1898. This provided the capital base for survival and growth of the smelter, which remained and prospered under the Canadian Pacific umbrella for almost ninety years. It was registered as the Consolidated Mining and Smelting Company of Canada Limited in 1906; in 1966, this name wasshortened to Cominco Ltd.The Rossland mines continued to supply copper ore for the smelter until the late 1920s, but lead-silver ore also became available from the contemporary mining boom in the Slocan area, about 80 km away. In 1901, the Trail smelter diversified into lead; and when the CM&S Co. acquired the St. Eugene Mine at Moyie and the Sullivan Mine at Kimberley, the smelter was guaranteed a firm supply of lead ore. The company also purchased the West Kootenay Power and Light Company, which even before the turn of the century had constructed the first of four hydroelectric generating plants on the Kootenay River near Trail. This acquisition assured the CM&S smelter and its local mines of a stable power supply and the opportunity to diversify into power intensive technology."

Jan 1, 1988

By C. A. Sutherland

"Smelting of copper-gold ore from nearby Rossland mines started at Trail in the 1890s. As ore from the Rossland mines became exhausted, lead smelting offhand-sorted galena orefrom other British Columbia mines was initiated. With the development of flotation technology for the separation of lead, zinc, and iron sulphides in the first two decades of this century, the large Sullivan orebody at Kimberley, British Columbia, became the foundation for the growth of a major zinc and lead smelter at Trail. Lead smelting began in 1901, electrolytic zinc in 1916, and by 1984, the Trail metallurgical complex had produced 10 million tons of each metal. Its present capacity is 270000 tonnes per year of zinc and 110 000 tonnes/year of lead.This paper reviews the history of technological changes in the Trail production plants, emphasizing the zinc plant modernization program started in the 1970s, and also the planned introduction of the QSL oxygen lead smelting process in the late 1980s. Lead modernization will increase production capacity to a maximum of 160000 tonnes per year.IntroductionCopper-gold ore was discovered at Rossland, British Columbia, in the year 1890, starting a mining industry that was to last over three decade s. Selected ore was at first transported at high cost to distant U.S. smelters, so there naturally followed a decision to construct a small copper smelter to process the local ore to matte. It was built in 1896 at the mouth of Trail Creek on the Columbia River, about 10 km from Rossland. This little smelter was to develop and diversify in the next 90 years into the world's largest lead-zinc produce.The mining boom that occurred in the northwestern United States and southeastern British Columbia in the period of 1890 to 1910 saw the brief operation of many small local smelters. The only one to survive was the smelter at Trail. The circumstances that permitted its continued life and subsequent growth, form a fascinating history of business deals, litigation, and steady technical progress.Early investment in local railway transportation and options by F.A. Heinze, the smelter' s founder, attracted the attention of the Canadian Pacific Railway Company, which purchased Heinze' s assets in 1898. This provided the capital base for survival and growth of the smelter, which remained and prospered under the Canadian Pacific umbrella for almost ninety years. It was registered as the Consolidated Mining and Smelting Company of Canada Limited in 1906; in 1966, this name was shortened to Cominco Ltd."

Jan 1, 1988

By G. E. Agar

This paper deals with the prediction of locked cycle flotation results from data developed from individual batch tests. A postulate is made that the distribution of material in a separation stage is determined by the chemical conditions and the flotation time and that this distribution can be characterized by split factors which are constants for a fixed set of conditions. With this premise, it is demonstrated that a steady-state balance can be calculated for a circuit. Although the necessary equations can be solved algebraically, a computer program was written that uses an iterative technique to arrive at the steady-state balance. The program is written so that a variety of circuits can readily be simulated. A number of examples are examined to demonstrate the validity of this simulation procedure. The sensitivity of the material balance to changes in the split factors was examined. Data developed from different flowsheets are presented on sulphide ores, on copper-nickel separation and on silver flotation.

Jan 1, 1978

By R W. Hutchinson

Cupreous pyrite deposits in Cyprus have many geologic similarities to Canadian massive sulphide copper-zinc ores as well as certain significant differences. A comparison of the Cyprus and Canadian deposits indicates a complex genetic history for the latter and suggests that their origin should be re-examined. The Cyprus ores occur in subaqueous extrusive rocks near and at the top of a Cretaceous volcanic pile or igneous complex. The rocks have not been deformed, nor have they been deeply buried or deeply eroded. Apparently the ores formed near or at surface in the top of the volcanic pile by a volcanic-exhalative process and from an ore-fluid of volcanic derivation. The Canadian deposits are of comparable composition and have similar geologic set-tings, but occur in the most ancient Precambrian rocks. Their enclosing Keewatin greenstones have, in most places, been deformed, regionally metamorphosed and invaded by granitic intrusions. Comparison suggests that the Canadian ores also formed initially near surface in ancient Keewatin volcanic complexes by a syngenetic, volcanic-exhalative process. Subsequently, during orogenesis, they were deformed, remobilized under conditions of elevated pressure-temperature and re-emplaced as epigenetic bodies into

Jan 1, 1965

By J. Aiello

"A brief history of previous mining activity on Coal Mountain, near Corbin, British Columbia, is followed by a description of the steps leading up to the resumption of mining in /974 by Byron Creek Collieries. New developments, including a preparation plant, a rail spur and a totally enclosed facility, as well as operating techniques, are also discussed. IntroductionThe Corbin Mine of Byron Creek Collieries Limited is located in southeastern British Columbia, approximately 110 air miles southwest of Calgary (Fig. I), 15 miles south of Highway 3 via a newly constructed provincial road (Fig. 2). Development of the area began on July 30, 1905, when D.C. Corbin, a prominent businessman from the northwestern U.S., and his associate E.J . Robert s, 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 15,000 acres of land in the area , began to develop a mine.F.J. Roberts was responsible for the construction of the 14-mile 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 2,337,800 tons. This production was allocated to the mines as shown in Table 1. No.3, 4 and 6 mines were operated intermittently from 1931 to 1935."

Jan 1, 1980

By W. T. Martson

ABSTRACT Sooner or later, every producing mine faces the question of fill. This paper invites consideration of mill tailings as an economical, efficient, and quantitatively adequate source of such fill. Some of the advantages, disadvantages, methods of utilization, and methods of treating mill tailings for sand recovery are covered. ADVANTAGES AND DISADVANTAGES OF SAND FILL DISREGARDING economic com-promise, that material which supports the greatest applied load with the least compression is the best choice for fill. Table I, reproduced from U. S. Bureau of Mines Bulletin 60, is offered as evidence of the adequacy of hydraulically placed sand. Table II gives the results of tests made in an effort to determine the reason for the difference between load hearing qualities of dry-placed and hydraulically-placed sand. From these, it would appear that hydraulic placing gives a denser initial packing, with corresponding higher, and faster development of, load bearing qualities. Assuming this to be true, then if sand from mill tailings can be placed underground economically, it is the superior fill material. Table III summarizes cost data available. The most cursory glance through the available references (2, 5, 6, 7, 8, 9) will show .that the major benefit from the adoption of sand fill is a decrease in the non-productive fill ?cycle of a working place. This, it is estimated, increases the output of an individual stope by from 25 to 50 per cent. The advantage of reducing the number of required working places for a constant daily production is obvious.

Jan 1, 1951

By Cale J. Dubois

At Cameco Corporations' Cigar Lake Project, large excavations are developed on the 480 Level and 500 Level must remain stable for at least 15 years to host underground processing infrastructure. Following the successful dewatering of the mine in October 2009, subsequent internal rockmechanics investigations augmented by third party technical investigations; determined that to keep the back of the Water Flush Crusher/Run-of-Mine (WFC/ROMs) excavation stable; required a rehabilitation strategy to mitigate deterioration/deformation of the WFC walls and intersection pillars. The mechanism of failure propagating the movement of the excavation walls is understood to be controlled by the presence of a dominant E-W striking and steeply dipping foliation within a relatively weak and mildly altered rockmass sub-parallel in strike with 14 meters high walls and an intersection span approaching 15 meters. The application of open and resourceful communications between site mining engineers, geologists, contract mining staff, construction management experts, corporate mining and civil engineers, and third party technical experts resulted in a multi-faceted short-term ground support strategy consisting of standard bolting and screening, deep-seated modified-strand cable bolts coupled with heavy gauge mesh straps, rockmass reconditioning using low-pressure grout injection, and horizontal cable-lacing for the intersection pillars applied in lifts using a top-down methodology. The intention of the short-term strategy was to stabilize the excavation so that a long-term structural steel support installation - consisting of composite concrete walls, and arch support applied to the side walls and crown of the back - could be constructed safely. This paper summarizes the evolution of the short and long-term ground support strategy and criteria for the WFC/ROMs excavation developed using elements of civil, mining and hydrogeologic design.

Nov 1, 2011

Originally developed as a step change in ultrafine grinding efficiency, the IsaMill? has made inroads into conventional ball mill and tower mill mainstream grinding duties during the last 5 years - beginning with the Anglo Platinum mainstream grinding projects in South Africa. At the 2006 SAG Conference, plant testwork on the incorporation of IsaMill? technology into the McArthur River (Northern Territory, Australia) Pb/Zn primary grinding circuit was reported. The IsaMill? has now become an integral component of that circuit, treating up to 1mm top size feed and directly producing P80 45 µm rougher flotation feed. Two 1.1 MW IsaMills? are now used in this duty contributing to a 27% increase in overall plant throughput and a reduction in rougher feed size distribution. In this paper, we report on the current state of development and performance of the IsaMill? in the primary grinding duty at McArthur River and also consider future directions.

Jan 1, 2012

By D. W. Euler, D. G. Brophey

"In an attempt to address the issue of rising labour costs, and to improve productivity, a laser-based system to guide underground LHDs and trucks has been developed. This comprehensive system is known as the Opti-Trak system.Essentially, the vehicle is equipped with front and rear-mounted lasers which scan a reference strip mounted on the drift back. The vehicle follows this reference strip and in addition, based on reflective bar codes mounted beside the reference strip, initiates certain functions (i.e. dump cycle, speed change, brake check, etc.). Any programming that is drift-specific is handled by the positioning of the reference strips and bar codes. Consequently, the vehicle can easily travel to many different haulageways or branches, providing the reference strip and bar codes are in place.The advantages of this system are an immediate elimination of haulage operator costs and an increase in available hauling time to 7 hours out of an 8-hour shift as compared to the typical 5Y2 out of 8 hours that a manned haulage system offers.This paper describes the Opti-Trak system and the benefits to be realized from automation of mine haulage requirements."

Jan 1, 1994

By J. S. Brock

Magnetic, electromagnetic and gravimetric surveys have played an important role in the mineral exploration leading to the discovery of three major massive sulphide deposits in the Anvil-Vangorda area of the Yukon Territory. During 1964 and 1965 a saturation prospecting program, relying heavily on the integrated use of airborne and ground geophysical survey techniques, led to the discovery of the Faro deposit, which was subsequently proven to be a 63-millionton lead-zinc orebody. Locating the Faro deposit, the largest found to date in this overburden-covered region, involved an exploration sequence requiring the selection of a favourable geologic environment, aeromagnetic and electromagnetic surveys, property acquisition of anomalous areas and detailed ground geophysical surveys, followed by rotary drill testing, detailed gravimetric surveys and diamond core drilling.

Jan 1, 1973

By K. L. Boyd

"Can the increasing tonnages of ore and waste mined today be accommodated simply by using bigger and better crushers? This paper reviews the latest primary crushing and large cone crusher designs. It highlights how—in addition to using the larger crushers now available—maximizing the utilization percentages in each stage of the rock size reduction circuit will assist in meeting the larger production requirements of existing and new mining operations. Its goal is to help consultants and operators select the optimal equipment and custom-designed items in material handling from the mine to the mill, maximizing operating hours per year.RÉSUMÉ Le recours à des concasseurs plus grands et plus performants suffit-il à gérer l’augmentation du tonnage du minerai et des déchets que l’on extrait de nos jours ? Cet article examine les tous derniers modèles de concassage primaire et de grands concasseurs à cône. Il montre que, pour satisfaire aux exigences de production plus conséquente des exploitations minières existantes et nouvelles, il est important d’optimiser les taux d’utilisation à chacune des étapes du circuit de réduction de la taille des roches, en plus d’utiliser les concasseurs plus grands actuellement disponibles. L’objectif de cet article est d’aider les sociétés d’experts-conseils et les exploitants à sélectionner le meilleur équipement ainsi que des articles fabriqués sur mesure pour la manutention de la mine au concentrateur, en optimisant les heures d’exploitation par année.INTRODUCTIONAre larger crushers the answer to meeting the demands of existing or new mining projects for increased tonnage? Boyd (2002) predicted that larger crushers for primary and fine crushing would be beneficial and contribute to the further development of mineral processing. Larger crushers for primary and fine crushing applications have since become available.The rock size reduction process from the mine to the selected milling process facility has not changed since a person first broke a rock to get at the interesting mineralization within. The rock size reduction process circuit from the mine to the mill can be summarized in four stages:• stage 1: mining (rock breakage and fragmentation);• stage 2: prescreening (scalping);• stage 3: primary crushing; and• stage 4: fine crushing (secondary, tertiary, and quaternary).Plant throughput and ore delivery schedule will form the basis for flowsheet design and equipment selection. Once the project design criteria and the mine plan have been established, the circuit’s utilization percentage (percentage of hours when the circuit is being utilized) can be optimized for each of the four stages. The mining and process departments play a key role in the selection of the final comminution circuit, and both departments should be familiar with and contribute to the design of the circuit."

Jan 1, 2017

By C. George Miller

"As the influence of governments has become more widely felt, the use of research techniques to analyze policy has increased. Mineral economics, as one of the foundations of mineral policy research, has grown accordingly. Policy research and analysis has been carried out within governments, university departments and the private sector. Each of these institutional environments has characteristics which influence the topics of study, the approach, the methodology and the output of the research. A brief survey of recent research activities provides illustrations of trends and developments occurring within this organizational framework.A radically different organization, the independent research institute, has begun to make an impact on policy research in recent years, and will have an increasing importance in the future. Combining certain features of the traditional research organizations, it nevertheless has important differences which are essential to its effective functioning. An overview of the formation, goals, organization and operation of one such institute is presented."

Jan 1, 1976

By C. A. Hardie, G. F. Leichtle, J. A. Finch, J. A. Watson

"The recycling of wastepaper has become an important and common process worldwide. Techniques similar to those used in the mineral processing industry are used to produce high quality recycled fibres for use in newsprint. The mineral processing group at McGill University, in conjunction with the Pulp and Paper industry (Mechanical and Chemi-mechanical Wood Pulp Network), has adapted one of these techniques, column flotation, for the purpose of deinking wastepaper. This article describes the typical process of recycling wastepaper from a mineral processing point of view. It also presents results from McGill University’s flotation column test work at a Québec wastepaper recycling facility. IntroductionThe recycling of wastepaper has become an important and common process worldwide, including Canada which is now the world’s largest importer of wastepaper (CPPA, 1996). Much of the current drive to increase the utilization rate of recovered paper is a reaction to the solid-waste disposal problem that faces many Canadian and United States municipalities. The real problem in the disposal of solid waste is not the absolute amount of garbage that must be disposed of each year, but this amount in relation to available disposal capacity.Environmental restrictions on the creation of new landfill sites and incinerators (the two main options for disposal of municipal solid waste) have tightened the demand/supply balance in the solid waste disposal market. This shrinking availability of waste disposal sites in the face of increasing population with greater disposal requirements defines the Developed World’s solid waste crisis. Not only are there fewer disposal sites available, but the costs of using them is skyrocketing. These factors have increased government regulations mandating recycled paper content in newsprint. Conservation and environmental issues make the current drive for wastepaper recycling a real issue and business opportunity."

Jan 1, 1999

By P. Lind, A. Gagnon

"Goldcorp has embarked upon an ambitious, industry-leading, multi-year water use reduction effort. This is a proactive, voluntary effort that reflects our commitment to truly sustainable mining. This effort will focus on increasing water re-use and recycling, and reducing water inputs ultimately towards zero. All of our operating mines are expected to contribute to this effort and are currently in the process of developing plans to meet short and long term objectives. One of the largest needle movers to increase water re-use and recycling is in the area of tailings management. Within five to ten years at Goldcorp, it is envisioned that the need for wet tailings dams will be eliminated and that all new tailings facilities will consist of only filtered or dewatered tailings. Filtered tailings is developing into a mature technology with wide application in mine waste management. This paper describes a conceptual level evaluation on the transition from a slurry to a filtered tailings operation at the Cerro Negro mine in southern Argentina. Key benefits and challenges are highlighted.INTRODUCTION Goldcorp’s Cerro Negro operation is located in the Santa Cruz province in the Patagonian region of Argentina. Cerro Negro has been in operation since 2014 and commercial production was achieved on January 1, 2015. The processing capacity of the plant is 4,000 tonnes of ore per day and in 2016 produced 363,000 ounces of gold and 3.1 million ounces of silver (Goldcorp Inc., 2017). As the mine is located in a semi-arid area, it is important to evaluate technologies that could reduce freshwater consumption and maximize water re-use and recycle rates. The current tailings operation at Cerro Negro incorporates pumping of tailings slurry into a conventionally lined Tailings Storage Facility (TSF). Water is reclaimed from the tailings supernatant pond to the process plant via pumps, however, water losses occur due to evaporation and solution retention within the slurry tailings voids. Converting to a filtered or dewatered tailings operation would allow for increased water recovery prior to tailings disposal, and decreased water losses from evaporation and from retention in the tailings solids void space. This paper describes a conceptual level evaluation on the transition to filtered or dewatered tailings with the primary objective of moving closer Towards Zero Water."

Jan 1, 2017

By Andrew R. Marchbank

The application of biologically assisted methods for metal extraction in the mining industry has a long history, but development of modern techniques has been relatively slow. There is, however, a resurgence of interest in the industry with the recent development of methods to successfully treat base metals concentrates. Two major pilot plant programs for treatment of chalcopyrite concentrates have been initiated in the past year and results from one are beginning to be released. This paper provides an overview of methods that have been applied in the past; from the earliest deliberate applications of the technology, through the copper and uranium heap and dump leach applications, the more highly engineered agitated tank leach gold applications and the developments currently taking place in the industry.

May 1, 2002

By H. Rozovsky

"AbstractThis paper discusses the methods of handling air in a large asbestos mill presently being completed at the Jeffrey mine of the Canadian Johns-Manville Company in Asbestos, Quebec.The mill, being the largest single asbestos producer in the world and capable of handling over 14,000 tons of ore per day, requires vast quantities of air. A minimum of 2,500.000 c.f.m. is required or about 10 tons of air for each ton of ore milled.Short descriptions of the process and systems requiring this air are given, followed by details of the fans and filters which make up the heart of the mill.This 'draw through' system, located on the top or 12th floor, is an automatically .controlled volume-pressure system creating the required suction to draw .air throughout the mill building and its numerous air systems.The dry mechanical method of milling develops enormous quantities of airborne dust and fibre. A section of this paper is devoted to a description of the multiplicity of dust systems within a system to control, filter, and remove this dust.Finally, the paper describes the method of returning the filtered air to the• working floors or to the outside, with some notes on heat, humidity and dust counts.IntroductionGeneralTHE discussions in this paper deal only with operations where air movement is involved. No attempt is made to delve into production methods.The Jeffrey mine of the Canadian Johns-Manville Company, located about 100 miles east of Montreal, is the largest single asbestos producer in the world, being responsible for over half of Canadian asbestos fibre production."

Jan 1, 1955

By W. J. Tough

THIS paper offers examples of some of the typical calculations which occur in the ventilation of metal mines. The fi.rst section of the paper discusses the problems associated with natural-draft pressure; the second section presents the more common of the calculations concerned with the operation of mine fans; the third section illustrates the integration of the individual problems covered by the preceding sections into the larger problem of determining the operating characteristics of a fan for a particular mine duty. There is a very definite limit to the extent to which pure arithmetic can be successfully applied to the solution of min<; ventilation problems. As mines advance from the exploration, development, and initial production stage to the rime when underground workings become exceedingly complex, there is a considerable increase in the relative importance o theory and judgment in the solution of ventilation problems. These calculations illustrate the application of mathematics to ventilation, but they also in-elude examples of instances where arithmetic cannot be conveniently applied, and important estimates, based on judgment compounded of experience and a knowledge of the theoretical consideration involved, must be made. The inclusion of such estimates is intended as a guide and a warning to the reader; a guide in assisting him to recognize and estimate his own incalculables; and a warning that the solutions must not be blindly applied to his apparently similar problems. These sample calculations are intended to assist the reader in applying the theory contained in the standard texts on metal-mine ventilation. They have been selected from the ventilation experience of a British Columbia mine.

Jan 1, 1942

By J. R. Goode

"Canada developed pioneering rare earth solvent extraction methods to recover the rare earths and thorium as by-products of uranium recovery operations in Elliot Lake, Ontario, and was a major supplier of these key elements from about 1960 until 1990. At one stage, Elliot Lake was supplying perhaps one third of the world’s yttrium as well as much of its thorium. This paper reviews the development of Canada’s early rare earth and thorium production facilities. INTRODUCTIONThe rare earths and thorium were first identified in the early 19th century but were little more than curiosities for the next century. However, in the mid-1960s the invention of rare earth-based phosphors for the cathode ray picture tube used in colour television sets launched a major demand for certain rare earths.The use of thorium as an alloying agent in aircraft and missiles grew rapidly in the late 1950s. In the same period, demand for uranium for both weapons and power production soared. Also in the late 1950s, the Elliot Lake uranium-thorium-rare earth deposits (also known as the Blind River deposits) were discovered. This conjugation of events led to uranium production in the Elliot Lake camp, quickly followed by the co-production of thorium and, later, the rare earths.Uranium production in the Elliot Lake camp continued from 1955 to 1996. Thorium was produced continuously from 1959 to 1969. Rare earths were produced, intermittently, from 1965 to 1990. Complete production records are not readily available but unquestionably Elliot Lake made a significant contribution to world thorium and the rare earth production. This paper, presented earlier in an abbreviated form (Goode, 2012), is intended to present as much of the information that is available."

Jan 1, 2012