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By M. Silver, R. H. McCorkell

The effects of covering materials on radon emanations from uranium mine mill tailings were investigated. Granular materials with air in the spaces allow radon to pass freely. Moist covers of compost or soil decrease radon emanation from tailings. Water-saturated covers were more effective, and freezing the tailings with these covers further decreased radon escape. Water itself is a poor radon barrier probably due to circulation. Plants had no effect on radon emanation through soil. Although radon diffusion through water-saturated powders appears to be very slow and inefficient, about 25% of the radon escaping from the grains in water-saturated tailings diffuse to the surface and emanate when no cover is present. The radon escaping from tailings through covers of water-saturated compost or soil is no more than could be accounted for by radon produced in the covers themselves.

Jan 1, 1987

By W. A. D. Edwards

"The Edmonton region accounted for 40% of Alberta's sand and gravel production in 1981 (about 12 million m3). Most of this production was by commercial operations (75%) for use in essential public works projects (64% in road and asphalt production).Although the Alberta Geological Survey delineated 1157 million m3 of gravel, a number of areas are considered to be in short supply. An econometric model was used for forecast demand in the region. Predictions, based on this forecast and estimated supply, are that 15% of the region's gravel and 3% of the sand will be consumed by the year 2010.The City of Edmonton is the largest consumer of aggregate in the region. Approximately 40% of the gravel in Edmonton's current supply area (about 55 km radius) will be used by 2010. These estimates are considered optimistic because the supply figures do not account for sterilization of deposits - some has already taken place in the region. If 25% to 50% of Edmonton's current supplies (one major deposit) were sterilized it would result in $1,000 million of additional cost due to increased haulage alone.Information on the value of aggregate resources, the location of sand and gravel deposit s and forecast demand has been made available to all municipalities in the region to aid planners and regulators in effective future use of this important resource.INTRODUCTIONAlberta is the second largest producer of sand and gravel in Canada at ab out 50 million tonnes annually. Value of provincial production exceeded $120 million in 1985. In Albert a, aggregate is used primarily in road and building construction (about 50% and 15%, respectively) and is important in such activities as petroleum exploration, oil sands development and the forestry industry.The Edmonton region (Fig. I) accounts for about 40% of provincial production and has a per capita consumption rate of about 13.4 m3 of sand and gravel per annum. Although Edmonton dominates, with approximately 50% of regional production going into the city, aggregate is produced in every county and municipal district in the region.Sand and gravel is essential to the current way of life in the Edmonton region. The resource is valuable and dwindling. The Alberta Geological Survey (a department of the Alberta Research Council) has collected information on aggregate in this region for the last decade which ca n aid government planners and regulators in pre venting sterilization and misallocation of this critical resource. This paper is a summary of that information."

Jan 1, 1989

By Gary Hawthorn

"Laboratory testing, by Lakefield Research determined that, in spite of the relatively high pyrite content of the Golden Rose (GR) orebody, it would respond well to gravity concentration followed by either direct cyanidation or cyanidation of a flotation concentrate.Economics favoured the former choice which became the adopted process flowsheet.During the latter stage of the feasibility study, the Dekalb 500 tpd copper flotation mill became available in the Highland Valley of British Columbia. This plant was purchased by Emerald Lake Resources, and was moved to the Golden Rose minesite.The crushing and grinding circuit were retained and the original flotation circuit was replaced with a 400 mtd gravity plus cyanidation circuit. The plant commissioning commenced in August 1987, and by early September was processing 300 tpd.HistoryThe Golden Rose Mine was operated by Cominco during the period 1935 to 1941 processing 146000 tons grading DAD oz/t Au at a rate of 110 tpd .The process flowsheet consisted of gravity plus amalgamation followed by cyanidation.Metallurgical TestingThe underground mining areas were below the level of Emerald Lake, and had flooded on abandonment in 1942.Samples for metallurgical testing were collected from exposed faces underground once the mine had been dewateredin 1984.In spite of the anticipated high pyrite content of the ore samples, it was apparent from the success of the previous operation that the pyrite did not interfere with the gold recovery.Laboratory testing, at Lakefield, determined that, from a technical perspective, two metallurgical options existed, as shown in Tables I and 2.Note that the very high pyrite content of the ore precluded the possible direct marketing of concentrate. The process flowsheet, therefore, had to contain a cyanidation circuit for the operation to succeed financially.Although the anticipated metallurgy was excellent with either option, the 2.1 % increase in gold recovery with the gravity plus cyanidation option made this the clear choice."

Jan 1, 1989

By Umbreen Agha, Stephan L. Chryssoulis, A. Margaritis

"The deportment of gold in samples of the biooxidation feed and product from the Harbour Lights mine in Western Australia was determined using optical microscopy and microbeam techniques such as Secondary Ion Mass Spectrometry (SIMS), Time-of-Flight Laser Ionization Mass Spectrometry (TOF-LIMS), and Electron Probe Microanalysis (EPMA). The main objective was to determine the mechanisms by which acidophilic bacteria (Thiobacillus ferrooxidans) liberate refractory gold which is locked in a sulphide minerals host as visible gold inclusions (> 0.1 µm) and as submicroscopic or 'invisible' gold.Using the integrated mineralogical approach approximately 99% and 100% of the assayed gold in the biooxidation feed and biooxidation product was accounted for. The results were compared to and verified by chemical assays.The gold deportment study indicates that during biooxidation, locked visible and 'invisible' gold is rendered cyanidable by the direct action of Thiobacillus ferrooxidans as well as indirect chemical leaching. Visible gold which is enclosed in sulphide minerals is liberated or partially exposed and is therefore rendered cyanidable as the host mineral is oxidized and dissolved. 'Invisible' gold either coalesces on the surface of the host sulphide mineral as the particle is dissolved or is released into the liquid phase and immediately adsorbs onto the surface of other ore particles with a net negative charge.The shakeflask suspension indicates that direct bacterial oxidation pits and channels correspond to zones of 'invisible' gold and arsenic (in pyrite) enrichment in the host sulphide mineral."

Jan 1, 1996

By Robert B. Parsons

"Canadian income tax legislation contains a number of provisions which serve to facilitate the structuring of business arrangements, including mineral resource ventures. These rules are often fairly complex and not easily understood. This article attempts to explain in plain and understandable language the mechanics and benefits of one of the more frequently encountered provisions, the ""Section 85 election"".IntroductionThe Canadian resource industries are probably singled out for more special attention under this country's tax legislation than any other industry. This special treatment is, of course, not always welcomed by the industry, such as where unnecessarily restrictive taxation is perceived to exist or where agonizingly complex tax legislation must be dealt with. On the other hand, certain provisions in the tax legislation treat the industry in a relatively favourable manner, including a number of rules which, in recognition of the high risk and capital requirements of the resource sector, serve to facilitate the structuring of resource ventures."

Jan 1, 1984

By J. E. Nesset

"This paper discusses the importance of considering residence time distribution (RTD) in the design of flotation and mixing circuits and in the analysis of operating problems. The experiences and successes of Brunswick Mining in this area are covered and include: the development of a practical RTD measurement technique using pulp conductivity, baffle installation to improve the RTD of existing process equipment, and the method in which RTD considerations have been used to design the newest flotation and conditioning operations IntroductionThe use of residence time distributions (RTDs) in the design and analysis of unit operations is well understood by the chemical engineering profession in while mineral processing engineers have tended to rely on empirical and rule-of-thumb factors. For example, in scale up from laboratory and pilot test results to full size flotation plant design, empirical rule s are often used to establish residence time and number of cells in the bank. Coleman suggests a factor of at least 2, and up to 5 for gold ores, be applied to laboratory determined flotation times. This is further illustrated in Table I, taken from Denver equipment. The number of cells in series to achieve the required retention time while minimizing short-circuiting has generated a variety of conclusions (Table 2). Obviously there is less than complete agreement on the subject. Young notes that a clear difference of opinion has emerged and cites as extremes, (i) the publications of Outokumpum showing unimpaired recovery for its largest machines (38 m3) compared to equivalent retention times for numerous smaller machines, and (ii) the experiences of Eastern European countries where the practice is to install banks of 30 unit s or more, operating in series, often with unit retention times of only a fraction of a minute.The empirical factors used by engineers presumably account for other than tested feed conditions, inefficiencies in large continuous machines, inevitable day-to-day circuit disruptions, gradual equipment deterioration and any other safety factor the engineer feels compelled to incorporate. An understanding of RTD concepts and techniques should help the practicing mineral engineer to develop more soundly based factors. Thi s paper relates the experiences of Brunswick Mining in using RTD techniques in the unit operations of flot ation and mixing"

Jan 1, 1988

By J. E. Nesset

"This paper discusses the importance of considering residence time distribution (RTD) in the design of flotation and mixing circuits and in the analysis of operating problems. The experiences and successes of Brunswick Mining in this area are covered and include: the development of a practical RTD measurement technique using pulp conductivity, baffle installation to improve the RTD of existing process equipment, and the method in which RTD considerations have been used to design the newest flotation and conditioning operations. IntroductionThe use of residence time distributions (RTDs) in the design and analysis of unit operations is well understood by the chemical engineering profession in while mineral processing engineers have tended to rely on empirical and rule-of-thumb factors. For example, in scale up from laboratory and pilot test results to full size flotation plant design, empirical rule s are often used to establish residence time and number of cells in the bank. Coleman suggests a factor of at least 2, and up to 5 for gold ores, be applied to laboratory determined flotation times. This is further illustrated in Table I, taken from Denver equipment.The number of cells in series to achieve the required retention time while minimizing short-circuiting has generated a variety of conclusions (Table 2). Obviously there is less than complete agreement on the subject. Young notes that a clear difference of opinion has emerged and cites as extremes, (i) the publications of Outokumpum showing unimpaired recovery for its largest machines (38 m3) compared to equivalent retention times for numerous smaller machines, and (ii) the experiences of Eastern European countries where the practice is to install banks of 30 unit s or more, operating in series, often with unit retention times of only a fraction of a minute.The empirical factors used by engineers presumably account for other than tested feed conditions, inefficiencies in large continuous machines, inevitable day-to-day circuit disruptions, gradual equipment deterioration and any other safety factor the engineer feels compelled to incorporate. An understanding of RTD concepts and techniques should help the practicing mineral engineer to develop more soundly based factors. This paper relates the experiences of Brunswick Mining in using RTD techniques in the unit operations of flotation and mixing."

Jan 1, 1988

By Leon C. Botham

?? Review of Requirements ?? Components of Modeling ?? Water Management ?? Tailings Management ?? Primarily a water management problem ?? Solids relatively easily contained ?? Process flows and runoff a continuous stream over life of mine ?? Need to allow this to safely happen over wide range of conditions

May 1, 2008

By R. L. Bruening, R. M. Izatt, N. E. Izatt, K. E. Krakowiak, S. R. Izatt

The need for selective metal separations has increased as the mining industry encounters more complex ore bodies and the demand for higher performance end products expands. Molecular Recognition Technology (MRT) is a green chemistry process that involves use of SuperLig® resins to selectively remove desired metals from a variety of solutions in mining and metals processing industries. Recoverable metal concentrations can range from multiple g/L to mg/L or less. The MRT separation process is based on green chemistry principles and can efficiently produce high purity metal products with minimal waste generation and energy usage. In this paper, applications of MRT to metal recovery and purification in the minor and specialty metals industry will be presented and discussed. Examples will be described involving cobalt, nickel, zinc, rhenium, iridium, indium, germanium, bismuth, and cadmium, as well as removal of lead and iron from process streams.

Jan 1, 2015

By Robert B. Parsons

"The Department of Finance introduced draft amendments to the resource allowance regulations on July 23, 1992 that effectively nullify the decision in the Gulf Canada Limited case. Prior to the amendments it appeared that only ""directly"" related general and administrative, capital cost allowance and scientific research expenditures had to be deducted from resource profits. Now ancillary expenditures are required to be deducted. Consequently, the ability of taxpayers to claim the resource allowance is curtailed.IntroductionOn October 25, 1990 it was almost certain that taxable mines were going to get a break. The Federal Court-Trial Division had just decided in Gulf Canada Limited's favour to allow it to claim resource related tax benefits larger than what Revenue Canada evidently wished. Revenue Canada appealed first to the Federal Court of Appeal and then to the Supreme Court of Canada. On January 10, 1992 the Federal Court of Appeal agreed with the Federal Court decision and on July 2, 1992the Supreme Court declined to hear any further appeal. A mere three weeks later, on July 23, 1992, the Department of Finance issued draft ""clarifying"" measures to amend the calculation of the resource allowance. These measures effectively nullify the benefits that arose under the decisions of the Federal Court."

Jan 1, 1992

By W. O. Karvinen

"In the Timmins area, a close spatial and chronological association exists between gold deposits and two major stratabound carbonate-rich members and related quartz-feldspar porphyries. Synvo/canic and metamorphogenic are the two main types of mineralization recognized. Synvolcanic ores include the stratiform quartz-ankerite ""veins"", pyritic carbonates and chert-carbonate-tuff sedimentary rocks and epigenetic ventrelated breccias and stringer zones. Metamorphogenic ores consist of quartz-carbonate fracture fillings in dilatant zones developed during various phases of regional deformation and metamorphism. They are classically epigenetic in character.The evidence suggests a primary syngenetic enrichment of gold on the ocean floor and in vent areas during submarine felsic volcanism and related exhalative-hydrothermal activity followed by further enrichment into quartz-carbonate stockworks during regional deformation and greenschist metamorphism.Although normally thin (a few hundred metres), carbonate members in Archean volcanic terrain represent intense hydrothermal activity which could have transported and enriched gold. They should be used to locate fossil vents and structurally favourable zones where economic concentrations of gold may be found."

Jan 1, 1982

By P. R. A. Andrews, R. K. Collings

"There are more than thirty-five deposits or occurrences of celestite in Canada, chiefly in Newfoundland, Nova Scotia, New Brunswick, Ontario and British Columbia. Deposits of economic interest are the Lake Enon and MacRae deposits in the Loch Lomond district of Cape Breton Island, Nova Scotia. Two Cape Breton deposits were operated from 1969 to 1976 by Kaiser Celestite Mining Limited, which supplied an upgraded celestite concentrate to an associated strontium carbonate plant at Point Edward, near Sydney.The MacRae deposit is of current interest because of its possible development for strontium carbonate production using the ""black ash"" process. This process involves chemical leaching, rotary kiln calcining with petroleum coke, washing and treatment with carbon dioxide.Celestite is the basic material used in the manufacture of strontium chemicals, principally strontium oxide, carbonate, nitrate, chromate, chlorate, chloride, sulphide and phosphate. Strontium chemicals, in turn, are used in the manufacture of glass and ceramics, in pyrotechnic devices, in the production of strontium metal and in other metallurgical applications. Recently, strontium ferrites have been introduced into permanent ceramic magnets."

Jan 1, 1991

By Lawrence Devon Smith

"The concept of risk is well established in the mining industry. It is acknowledged when estimates of reserves are expressed as proven or probable, when mining and metallurgical recoveries are applied to the ore, and when contingencies are added to costs. However, it is difficult to provide a quantitative assessment of risk. The significant sources of risk in a mineral project and how these are addressed in project evaluations are discussed.The discount rate is examined as a fundamental means of reflecting risk in discounted cash flow evaluations. Current industry practice is discussed, and a methodology for the analysis of risk levels is proposed that assesses the constituent components of the discount rate: real interest, mineral project risks, and country risk.IntroductionThis paper examines the components of the discounted cash flow discount rate and proposes a method of estimating project-specific discount rates. The motivation for this work comes from experience of project evaluations in which owners and purchasers had agreed on virtually every aspect of the evaluation except how much the project was worth. Agreement was reached on reserves, grade, recovery, capital costs, operating costs, taxes, and, by combining these components, even on the final cash flow values. The only difference in opinion concerned the discount rate to be used in the calculation of the net present value. Depending on the life of the project, such differences of opinion can cause a variation of more than 50% in the value placed on a project! This is illustrated in Figure I."

Jan 1, 1995

By Richard Murphy

"The general geology of the Great Bear Lake area has been described by; D. F. Kidd in the Summary Report of the Geological Survey for 1932. A brief description of the Eldorado mine was prepared by C. S. Lord for Memoir 230; Mineral Industry of the Northwest Territories; published by the Geological Survey in 1941. Recently; a detailed geological examination of the mine area has been initiated by the Geological Survey and; under A. W. Jolliffe's leadershif; J. D. Bateman; H. B. Thurber; and M. Feniak have prepared a number of maps and reports; as yet unpublished. Detailed mapping of the mine has been carried out since August; 1943; by A. W. Esty.Kidd has shown that, in the largely granitic country along the east side of Great Bear lake, the Echo Bay district is one of several underlain by older rocks . These he has divided into the Echo Bay and Cameron Bay groups. The former are strongly altered sediments, .porphyries, and lavas; the latter and younger group is predominantly sedimentary and far less altered. Associated with the granite, which everywhere intrudes the sediments and volcanics, are earlier differentiates. Later than all these rocks are various basic intrusives, collectively termed diabase. All the rocks are of Precambrian age."

Jan 1, 1954

By A. Christoffersson, T. Nillson-Wullf, H. R. Manouchehri

"Mining industry has been the building blocks for human development through millennia and will continue to play its role in sustainability and meeting society’s needs for raw material. In the way towards sustainability, the next generation of efficient and heavy duty of Sandvik’s crushers, CH860 and CH865, are introduced for efficient crushing. As the secondary, tertiary and/or pebble crusher, these new crushers are designed to over perform in tough mining environment. Featuring higher crushing forces relative to the mantel diameter and 500 kW motor, combined with advanced automation system, i.e., sophisticated HydrosetTM and Automated Setting Regulation (ASRTM), combined with overpressure system with dedicated air supply in dust collar, etc., the new crushers provide higher safety, productivity, and reliability with the same foot-print of conventional cone crushers.Since crushers are more energy efficient than mills it makes sense to effort in fine crushing to save energy and protect environment. That has been the logic behind development and introducing stronger and more efficient crushers by Sandvik. The results on crushing hard iron and gold ores by CH865 have proven its efficiency in fine crushing at a higher productivity, availability and reliability rates through increasing throughput for defined size fraction and extended crushing chamber liner life.Within this paper the performance of the CH865 to deal with two different ores are presented discussed with a glance at how the downstream milling process can be benefited by saving energy and reducing the operation cost. In plant practice, the implementation of the new CH865 provides between 25 and 30% of the crushed ore in the size range of first step milling, i.e., < 2 mm, that offers opportunity for reduction in energy consumption in milling and even changing the process plant configuration by directly forwarded that part to gravity separation. Furthermore, potential of converting the rod mill to ball mill to improve productivity has been considered by plant engineers. Furthermore, some potential applications for such efficient crushers are brought into considerations and discussed. The new developments provide about 30% higher crushing force to efficiently deal with competent ores and pebbles. The CH860 and CH865 crushers are well suited to replace conventional secondary and tertiary crushers respectively; nevertheless, CH865 is virtual option for pebble crushing in SAG and AG milling circuits."

Jan 1, 2016

By Robert B. Parsons

"Ontario and Quebec taxpayers will have to dig deeper into their pockets to pay more tax, according to budget papers tabled in these provinces in May 1993. Individuals will be hardest hit, but corporations will also have to ante up in the face of higher rates, reduced deductions, and new taxes.Up, up, and away...Somewhere in the bleak picture of the 1993 Quebec and Ontario budgets, there is a bit of good news for the mining industry.Careful scrutiny reveals:• Ontario will correct a capital tax provision which inadvertently penalizes flow through share issuers;• Quebec&apos;s flow-through incentives will be extended to December 31, 1995; and • both Quebec and Ontario will allow deductions for mine site reclamation payments.The industry may also find some comfort in the fact that Ontario&apos;s new corporate minimum tax will be profit-based (unlike the federal minimum tax), so that non-producers should not face a liability for this tax. There is some concern though, about Quebec&apos;s announcement that the refundable credit mechanism in the Mining Duties Act will be reviewed."

Jan 1, 1993

By M. Sukhram

In the year 1992, T.A. Utigard published a paper titled "The measurement of the heat-transfer coefficient between high temperature liquids and solid surfaces." In that work, he instrumented an agglomerate of materials with thermocouples to infer the heat transfer coefficient of a high temperature liquid on a solid. The purpose of that research was to help in the design and operation of metallurgical reactors. Since that time there have been many researchers that have worked to characterize heat, mass, and momentum transfer phenomena in high temperature metallurgical processing operations. This paper presents results from the author’s experience with instrumenting thermocouples in copper elements coated with carbon to infer velocity of high temperature liquid metals. It also presents a methodology to determine velocity of a high temperature liquid by inferring the local heat transfer coefficient at a solid-liquid interface

Jan 1, 2015

By Janet E. Halliwell

In keeping with the traditions of the Science Council of Canada - an independent and forward looking agency that applies broad and multidisciplinary analyses to the various issues it examines the author indulges in a holistic approach to the integration of the environmental, scientific, economic, and cultural concerns. This paper will characterize the changing conditions which the mining industry is facing. It will then explore the changing expectations of society with respect to environmental sustainability and how those attitudes in turn, must influence the strategic directions and attitudes of the industry, and within that, the role of science and technology.

Jan 1, 1991

By Jacques Ouellet

Outline What is Microwave energy Investigation of transparency of 40 minerals Melting of Andesite in a MW oven Numerical modeling /Computer Simulations o FEM analysis ?? Some laboratory experiments o Particle Modelling Mw Application to Rock Breakage o A MW Rock Drill Prototype Conclusions What is Microwave energy Microwave energy is an electromagnetic wave consisting two electronic & magnetic wave traveling perpendicular to each other and transporting energy with the speed of light.

May 1, 2008

By R. A. Horn, S. M. Telfer

"Canada has a per capita GDP second only to Japan among the G7 countries and a positive trade balance which ranks third among the world&apos;s major economies. International trade represents a very large part of the national economy and as a proportion of GDP is larger than that of all the other G7 countries with the exception of Germany. On the negative side the Canadian current account deficit relative to the size of the economy is significantly worse than that of all major industrial countries, due mainly to the cost of servicing an immense foreign debt and to a large and worsening negative trade balance in manufacturing.The outflow of money may be reduced by increasing the productivity and competitiveness of those sectors of the economy in which Canada already has a leading competitive position and which have the potential for further growth. The mining industry is uniquely qualified in this respect in that Canada is the western world&apos;s largest producer of metals and mineral products and has the geology and the exploration skill to replenish reserves assuming that an adequate level of investment is maintained. In 1989 the minerals industry contributed $8 billion to the country&apos;s balance of payments and with the exception of forestry is the only sector of the economy which has shown consistently increasing foreign earnings over the long term.In recent years there has been a decline in exploration in Canada and a significant increase in countries such as Chile. The demand for hard currency to finance the development of the newly emerging capitalist economies of the CIS and Eastern Europe is also driving these countries to seek foreign investment to allow them to exploit their natural wealth more efficiently. Canada is therefore facing growing international competition for risk capital and in the future its trade surplus will probably decline in the face of lower cost foreign production.Canada rightly exercises a high level of environmental control on its mining operations; however a significant deterrent to investment is the fundamentally unjust application of the many provincial and federal environmental laws, under which a mining company, even if it takes every measure to protect the environment, runs the risk of eternal and unlimited future liability. If this situation is not rectified the effect will be an increase in global pollution as mines in countries with more lax application of law and regulations controlling environmental damage replace those of Canada. Tax benefits and incentives are a more efficient means than arbitrary regulations in minimizing environmental damage."

Jan 1, 1994