Search Documents

By Anna Szostak-Chrzanowski, Adam Chrzanowski

"New techniques in monitoring surveys and new methods in the analysis and prediction of ground subsidence are being developed in the Department of Surveying Engineering at the University of New Brunswick (UNB). The new surveying techniques include a telemetry monitoring system developed at UNB in cooperation with CANMET, and use of the satellite Global Positioning System. A generalized approach to the analysis of deformation surveys has been developed which permits an integrated analysis of geodetic and geotechnical measurements in geometrical modelling of ground subsidence. A computer program, FEMMA, has been developed for the elastic and non-linear elastic analysis and the deterministic prediction of deformations using the finite element method.IntroductionResearch and development of new monitoring techniques and new methods in the analysis and prediction of ground subsidence in mining areas is an integral part of a broad research program on deformation surveys which is being carried out in the Department of Surveying Engineering at the University of New Brunswick.The research concentrates on:developmentof a general method for predicting deformations with an emphasis on the use of the non-linear elastic finite element analysis; development of a generalized approach to the geometrical analysis of deformation surveys with an integration of geodetic and geotechnical measurements; and development of new monitoring techniques with an emphasis on continuous data acquisition and application of new space techniques such as the satellite Global Positioning System (GPS).This paper gives a brief report on the progress and recent developments within the above program."

Jan 1, 1987

By H. T. John

"The objective of this paper is to demonstrate how the optimum cut -off grade can be calculated for typical large tonnage openpit mines. In the examples, it is assumed that the concentrator tonnage is fixed and that there are no market restrictions. The mining rate is assumed to be variable. This is usually the situation at an operating property.ModellingA model of the ore body is required to examine alternate cutoff grade strategies. The model must be accurate in its relationship between grade and tonnage. Table I shows a typical relationship between ore tons and grade for various cut-off grades. The average strip ratio is also shown. For higher cutoff grades, the ore tonnage is decreased and the ore grade is increased. Strip ratio increases with the cut-off grade.Using the relationship between ton s and grade, and assuming a homogenous, long life orebody, a simple calculation of the optimum cut-o ff grade can be made. The objective is to maximize the present value of cash flows. For the long life homogenous orebody example this objective is satisfied by maximizing present cash flows.Cash flow is calculated by subtracting operating cost from revenue . Operating cost will increase with the cut -off grade as the strip ratio increases."

Jan 1, 1985

By A. Nielsen

"The Polaris mining operation (Fig. I) is located on Little Cornwallis Island in the Canadian Arctic, an area with a very limited shipping season and a hostile climate. The operation consists of the underground works, barge-mounted concentrator facilities, concentrate storage and shipping facilities, a personnel accommodation complex and an airstrip.The electrical energy for the operation is provided by four 2.3 MW diesel-generators installed on the barge. The power is distributed through a 4.16 KV system connected directly to the generators and to the large motors. All other loads are supplied at 600 V or 120 V.The power plant has been designed as a Total Energy System with maximum energy efficiency and thus designed for maximum heat recovery. The waste heat recovered on a year 'round basis is expected to be sufficient for the process heating and drying as well as the space heating for offices and accommodations. The engine cooling system consists of two glycol-water loops, a "" cold"" loop for charge air and lube oil cooling and a ""warm"" loop for jacket water cooling. Each loop is complete with heat exchangers f or heat recovery and out-door forced air radiators to dispose of excess heat. A water loop in the concentrator area transfers the heat from the jacket water loop and the exhaust gas boiler to the space heating equipment, the process and the heating system for the accommodations. Part of the exhaust gas is diverted to the concentrate dryers.IntroductionThe Polaris Mine is a highly mechanized, trackless mine with access through a decline. Drill equipment is electrically powered to minimize fumes and heat. Dry development and production drilling eliminates the need for an underground water supply system.The concentrator, power generators, work shops and auxiliary facilities are located on a barge which is beached in a prepared berth on the shore of Crozier Strait. Oil storage tanks, concentrate storage and accommodation buildings are built on shore. The concentrate storage building ha s a 12-month capacity and is fed from the concentrator by a conveyor system.The accommodation building houses up to 240 people, includes administration office, dining and recreation facilities. The complex is housed in on e interconnected building with public use areas alternating with accommodation units.At full production annual concentrate shipments will amount to about 220,000 wet tonnes. This will be accommodated by about 8 shipments during the regular shipping period-August 15 to October 15. Re-supply of general cargo and fuel will be carried out annually in about 3 shipments within the same period."

Jan 1, 1984

By G. Grant Smith

In situ bulk density of coal is a variable applied to various aspects of coal resource evaluation, such as compositing ply analyses of coal attributes that are expressed on a weight per cent basis, and determining tonnages from volume estimates. Its value is a function of composition and porosity of the in situ material. When densities of ash-free coal, ash and water are fixed, in situ bulk density of a coaly mix can be expressed as a function of proportionate weight of ash in the mix. Correlations between in situ bulk densities and weight per cent ash contents of coaly mixes have been estimated for four general rank classes of coal (low medium volatile bituminous, high volatile bituminous, subbituminous, and lignitic).

Jan 1, 1991

"During the development of a mining project, samples are taken for metallurgical tests. The sample can be a composite sample made of material from a selection of various drilling products or a sample from a mining test. It can be also a sample from an existing plant in order to investigate process enhancement. This sample can represent several tonnes of material which are analysed and split for use in various tests.In the current case, a composite sample of gold ore is dedicated to a Gravity Recoverable Gold (GRG) test. The properties of interest are the head grade of gold, the size distribution of the material, and the gold assay per size class. The sample is mixed and a sub-sample is taken to measure the feed properties: the size distribution and the gold assay per size class. The remaining material of the sample is subject to the first stage of concentration using the laboratory Knelson concentrator. The concentrate is analysed in its entirety, while a sample of tailings is taken for the same analysis. The remaining part of tailings is subject to grinding to feed the second and third stages of concentration. Similar sampling is performed at each stage.The concentration performances are analysed in light of these measurements. But what is the accuracy of the measurements of the properties? Pierre Gy’s theory of sampling, associated with a heterogeneity model built using the GRG test results, will answer this question. The current paper presents, through a real example, the calculation of the errors of the measurements of size distributions and gold assays performed during the GRG test. The uncertainties of the concentration performances and liberation size estimate are then calculated and their impact on the results interpretation is analysed.INTRODUCTIONDuring the development of a mining project, samples are taken for metallurgical tests. The sample can be a composite sample made of material from a selection of various drilling products or a sample from a mining test. It can be also a sample from an existing plant in order to investigate process enhancement. This sample can represent several tonnes of material which are analysed and split for use in various tests. In order to take into account the ore variability in terms of gold deportment, it is recommended to perform variability studies (Dominy, Murphy, & Gray, 2011, Dominy, 2013) using samples representing various horizons or years of production. But for a given ore type, it can be necessary to perform many tests with different operating conditions (Brochot, 2012a). In that case, the variability of the samples is not due to the heterogeneity of distribution of the deposit, but only on the heterogeneity of constitution of the primary sample. The level of confidence associated with the estimated performance parameters is directly linked to the overall error (including sampling error) of the measurements performed during the tests."

Jan 1, 2016

By Poul Hansen

"In mid-1986, a world-class mining enterprise was created in Highland Valley, British Columbia, bringing together the copper mining operations of Lomex and Cominco . In 1988, Highmont joined the new partnership.Highland Valley Copper is the largest copper mine in North America in terms of both tonnage mined and tonnage milled, and it is one of the largest in the world. Due to its relatively low ore grade its production of copper in concentrate ranks about ninth in the Western World.The current eighteen year mine plan is based on ore reserves of 761 million tonnes. The daily milling rate is 133 000 tonnes. At the end of mine life, a total area of approximately 6500 hectares will have been disturbed. At this time, vegetation has been established on about 600 hectares and while work will be done during the operating years, it will not be until the end of mine life, about 2008, that the last half of the land can be reclaimed and revegetated.Once final reclamation has been accomplished, Highland Valley Copper will have completed its "" temporary use of the land"". In the meantime, about 1250people have had employment for about 50 000 man years, at wages ranking among the best in Canada.IntroductionTo provide and sustain our way of life, we need steel, copper, aluminum, zinc and many other minerals.To sustain mining, we must have adequate ore reserves and replacement of reserves as they are mined. Each year the search becomes more difficult as more of the Earth's surface is investigated and depo sits are mined. This calls for aggressive and sustained efforts.In British Columbia, past and present mining activities have disturbed less than one-tenth of one per cent of the land.With today’s technology, mining operations can be substantially reclaimed and thus complete the cycle of ""A Temporary Use of the Land""."

Jan 1, 1992

By D. Doyle, T. Cienski

"This paper presents and discusses the results of a detailed study conducted on the subject of energy consumption in the comminution of industrial minerals. The study was based on pilot circuit testing, plant operating data collection, detailed equipment data and literature research. The areas covered by investigations include: high efficiency classification; air classifiers for cement grinding circuits; grinding aids in dry grinding; and dry grinding circuit control based on particle size measurement. Results obtained indicate a large potential for the reduction of energy consumption, in particular in the cement clinker grinding circuits. Better classification techniques and correct application of grinding additives can significantly reduce power used per tonne of product and also substantially increase grinding circuit output."

Jan 1, 1992

By M. S. Moats

"The effects of commercial copper electrorefining additives (glue and thiourea) on the electrochemical removal of bismuth are of importance in copper production. It was found that Bi(III) electrodeposition occurs readily from acidic sulfate solution via a diffusion-controlled quasi-reversible reduction. The diffusion coefficient of Bi(III) was measured and found to be less than reported values of copper in similar solutions. The presence of thiourea and/or glue was found to accelerate or de-polarize Bi(III) reduction on stainless steel as compared to the inhibition or polarization of Cu(II) reduction. The additives also inhibited the dissolution of the Bi-Cu co-deposit during cyclic voltammetry. During short term deposition studies, the additives increased the concentration of Bi in co-deposited Cu-Bi products from solutions with low concentrations of Cu (<2 g/L). Bi deposition was significantly suppressed by increasing the Cu(II) concentration in the solution. The formation of a copper layer on the stainless steel electrode appeared to significantly suppress the reduction of Bi(III). This study demonstrates that glue and thiourea depolarize the deposition of bismuth on stainless steel. Therefore, the additives could be used to improve Bi impurity removal during third stage liberation.INTRODUCTIONThe production of high purity copper has been steadily increasing due to the wide application of the metal and its alloys in electrical and electronic products, infrastructure construction, industrial machinery and equipment, general products and transportation (Moskalyk et al., 2003). Most high purity copper is manufactured from copper sulfide mineral concentrates and/or scrap via a pyrometallurgical process followed by electrorefining (Navarro et al., 1999). During the electrorefining process, cast anodes of 99-99.5% purity are electrochemically dissolved into an acidified copper sulfate solution while high purity copper (>99.99%) is plated on stainless steel blanks or copper starter sheets (Davenport et al., 2002). The control of cathode deposit growth (purity and morphology) while maintaining a high current efficiency is of significant importance for copper refining (Ilkhchi et al., 2007). At typically applied current densities for industrial copper electrorefining, mass and charge transfer play important roles in the quality of cathodic products (Hiskey et al., 1998). If the real current density at some surface points is substantially higher owing to uneven current distribution, then rough spots can and will grow faster leading to nodules (Suarez et al., 1992). Nodulated deposits tend to capture solution and anode impurities (slimes) resulting in unacceptable cathode quality (Afifi et al., 1987). Furthermore, these nodules can grow until they eventually contact the anode leading to short circuits and current efficiency reduction (Ilkhchi et al. 2007)."

Jan 1, 2016

By Jean-Luc Collins

"The paper deals with the impact of fleet imbalance on a deterministic evaluation of shovel fleet productive capacity. It shows that if the fleet imbalance is overlooked, then estimated fleet productive capacity will be overrated.The paper shows that fleet imbalance inflates utilization, and care must be taken when using such statistics which are derived from reported field-equipment-hours. It shows that the utilization must be deflated by a factor called &apos;balancing efficiency"" in order to estimate shovel productive capacity correctly. The paper also shows how fleet imbalance can be controlled by managing idle time or downtime in an actual operation.The technique used for measuring the balancing efficiency factor is based on statistical analysis of equipment utilization."

Jan 1, 1980

By T. Gonzales, M. Maleki, M. Caçador, B. Climenhaga, H. Ghorbani

The campaign life of furnaces in the copper making industry is greatly affected by damage caused by normal operation cycling and abnormal conditions. Proper monitoring and assessment of the existing conditions and safe remaining life of the vessels and their refractory lining is key to prevent an unplanned early replacement. This paper presents an industry-proven refractory management program as well as a typical fitness-for-service assessment of a rotary vessel shell in order to extend the campaign life of copper making furnaces and enhance safety. The furnace refractory management system involves a comprehensive audit and monitoring program which has been successfully applied to several copper flash smelting furnaces over the past 15 years. The fitness for service assessment provides a methodology to estimate the remaining life of the steel components by evaluating the existing damage and future damage rate based on the historical survey data. The above practices can provide the operator with cost savings by extending the vessel campaign life in lieu of implementing more rigorous refractory lining and shell audits. INTRODUCTION Primary copper smelting is generally divided into two categories of flash smelting and open bath smelting. There are many different types of vessels that can be used to convert the copper concentrate to blister copper including, flash, Mitsubishi process, TSL (ISA/Ausmelt), SKS Bottom Blowing, Anode and Teniente/Noranda furnaces, reactors, and Peirce Smith converters. Each vessel has its own complex and intense environment which requires careful refractory and steel design to withstand the severe thermomechanical and thermochemical attacks within its campaign life. The campaign life of furnaces is greatly affected by damage caused by normal operation cycling and abnormal conditions. Proper assessment of the existing conditions and safe remaining life of the vessels and/or refractory lining is key to prevent an unplanned early replacement. This paper presents an industry-proven refractory management program as well as a fitness-for- service assessment methodology to estimate the remaining campaign life of copper making furnaces resulting in cost savings and enhanced safety of the operating vessels.

Jan 1, 2019

By M. A. Sobhi, L. Li

With the continuous reduction of mineral resources at shallow depth, more and more mines have to go deeper beneath the earth's surface to reach the ore zones. This increase in mine depth leads to a natural stress increase, which also raises the stresses around mine openings. This may result in ground instability, including the risk of rock bursts or exceedingly large opening closure. Stope backfilling is a well known solution to improve the ground stability condition. It also has the advantage of reducing the mining wastes disposed on surface, thus helping to reduce the environment impact from the industry. However, most available solutions for backfill design were developed for an isolated stope without taking into account the influence of mine depth, except for a few numerical analyses performed recently by Falaknaz and coworkers for the case of multiple backfilled stopes laying in the same level. In this paper, a numerical study is carried out to evaluate the stresses in backfilled stopes overlying a sill mat. The mine depth and the excavation of the underlying stope below the sill mat are both taken into consideration. Compared to the case of a single isolated backfilled stope, the obtained numerical results show that the stress magnitudes in the overlying backfill are considerably increased due to the excavation of the underlying stope. In general, the stresses increase with mine depth and backfill stiffness, but decrease with an increase in the surrounding rock mass stiffness. These results indicate that the barricade and sill mat backfill design should take into account the excavation of the underlying stope and the mine depth.

Jan 1, 2015

By Robert B. Parsons

"No Canadian or his family is likely to escape the effects of proposals for pension reform tabled on October 9, 1986 by Finance Minster Michael Wilson. New tax rules are proposed for Registered Retirement Savings Plans (RRSPs), company pensions, and other forms of retirement plans. Draft legislation is expected to be released in the first half of 1987.IntroductionOver two years ago on February, 15, 1984, Mark Lalonde, then Finance Minister, tabled two White Papers. The first, Action Plan for Pension Reform, proposed improvements to the public pension system and increases in the minimum pension benefits standards to be mandated by the federal government. Since then changes have been made to the Old Age Security, Guaranteed Income Supplement and Canada Pension Plan programs. Also, benefits provided under pension plans subject to the federal Pension Benefits Standards Act have been improved significantly.The companion paper, Building Better Pensions f or Canadians, proposed to standardize and, in many cases, improve retirement savings through private plans by revising the tax rule s. The tax proposals in the Notice of Ways and Means released by Finance Minister Wilson on October 9. 1986 implement, with modifications, the tax treatment of retirement savings originally proposed in the May 1985 budget in response to that second paper."

Jan 1, 1987

By Robert B. Parsons

"""I would be a rich man if I had a dime for every man hour spent by the bureaucracy on changing tax legislation."" Anonymous.The mind of a cynic might very well conjure thoughts about ""change for the sake of change"", given the protracted saga of federal sales tax reform in Canada. The latest chapter unfolded this summer when the Commodity Tax Review Group released its important report. Whatever sales tax changes, if any, are finally adopted will have profound effects on many aspects of doing business. The capital-intensive mining industry will not escape these effects.IntroductionThe Federal Sales Tax Review Committee, established by the Minister of Finance earlier this year, has published a report that is sharply critical of the government proposals to shift the incidence of federal sales tax from the manufacturer level to the whole sale level (sales to retailers). The Report recommends a continuance of the present manufacturer&apos;s tax, for the present, but with significant changes that would increase the tax cost on certain imports, smooth the administrative machinery and make appeals and determinations more open and equitable. For the longer term, the Report recommends a shift of the tax base to the retail level.Reform of the federal sales tax system has been under consideration for several decades. Briefly the history is as follows: 1940 Report of Rowell-Sirois Commission-proposed the eventual elimination of federal sales tax1956 Report of Federal Sales Tax Committee-proposed a shift in tax from manufacturer to wholesaler level1966 Report of Carter Commission-proposed shift to a retail tax1975 Discussion Paper on Federal Sales and Excise Taxation-concluded that retail tax conceptually best but provincial agreement/administrative problems present a major hurdle-proposed wholesale tax as best practical approach1977 Report of Commodity Tax Review Group"

Jan 1, 1983

By Robert B. Parsons

"The Canadian tax treatment of mining operations outside Canada is not as attractive as the treatment of Canadian operations. Further, the Canadian company that invests abroad a host of complex rules. This month, Tax Notes examines some of the major Canadian tax considerations confronting the Canadian company that wants to invest abroad. IntroductionCanadian-based mining companies are investing abroad more than ever before. These foreign investments trigger a complex set of tax rules that are distinct from the rules that apply to Canadian investments. In most cases, careful tax planning is mandatory if the company&apos;s tax liabilities are to be minimized. This article summarizes the main tax considerations that need to be taken into account with respect to a mining investment outside Canada.Branch Versus SubsidiaryOne of the first questions that arises in connection with a prospective foreign investment is ""Should we invest directly (that is, in a branch operation), or should we invest through a foreign subsidiary?"". In the case of a branch operation, the Canadian company owns and operates the business directly - that is, the foreign business assets are part of the Canadian legal entity. In the case of a foreign subsidiary, the foreign business operation is owned and managed by that subsidiary. The tax treatment of a branch and a subsidiary can be quite different."

Jan 1, 1994

By Robert Thomson

"The Cobalt camp is by far the most productive camp of the Temiskaming silver-cobalt area. The date of discovery, 1903, is an important one in the history of Canadian mining; from then on prospecting and mining grew rapidly to take the prominent places they now hold in Canadian life.At Cobalt, prospectors and operators, who were to play prominent parts in other Canadian camps, received their initial training. The exploration campaigns leading to the discovery of several new camps were organized at Cobalt, and a considerable part, indeed, of the funds for these campaigns were profits from mining at Cobalt.The discovery of the Cobalt camp was purely accidental, not the result of any purposeful search. Fred LaRose, a blacksmith employed in the construction of the Temiskaming and Northern Ontario Railway, discovered mineral, afterwards determined to be valuable, within a few feet of the right-of-way. This discovery became part of the very productive LaRose mine. The publicity given this discovery, particularly by Willet G. Miller, later Provincial Geologist of Ontario, led to the rapid development of the camp.ProductionCobalt is a great camp by virtue of its silver production; cobalt is also important, although clearly subordinate. Copper, nickel, arsenic, and bismuth are by-products of mining for silver and cobalt and have not been of great importance to date.The following table gives the metal content of ores, concentrates, etc. from the Cobalt camp for the years 1904 to 1954 inclusive, as reported by the mines (l):"

Jan 1, 1949

By M. A. Vos

"Cretaceous sands and clays underlie an area of approximately 5,000 km2 in Northern Ontario, southwest of James Bay. The deltaic deposits occur as a wedge of continental sediments to the north of an east-trending fault scarp referred to as the Precambrian Escarpment. They rest on older sedimentary formations of the Moose River Basin (Jurassic, Devonian) and are covered by glacial tills and marine sediments of the Quaternary period. Outcrops are restricted to occasional exposure in the deeply incised riverbeds.In 1975 and 1978, drill programs sponsored by the Ontario Government provided new information on the extent and quality of the deposits. Fourteen holes at approximately 12-km intervals were drilled to a maximum depth of 189 m by reversed- circulation chip drill methods. Some core was obtained as well. Analytical results show that the thickness of Cretaceous deposits exceeds 100m in several instances. Abundant kaolinitic clay and quartz sand of glass-grade quality, both unique materials in Ontario, are available in an area where hydroelectricity and lignite resources combine to enhance the energy outlook.IntroductionThe presence of refractory clay in deeply incised riverbeds in Northern Ontario was known to geologists travelling the rivers as early as 1875. Robert Bell (1877) reports outcrops of clay and lignite on Coal Brook, a tributary of the Missinaibi River. E.B. Borron in 1880 collected a sample of clay from the bed of the Missinaibi River which H.H. Croft of the University of Toronto considered to be ""nearly if not quite, equal to the Cornish clay used in the manufacture of English porcelain"" (Keele, 1920, p. 42). The Cretaceous age of the clay, sand and lignite deposits was determined with the help of plant remains collected by Keele. He referred to the deposits as the Mattagami series, which later became the Mattagami Formation."

Jan 1, 1982

By Gaétan Bourdages

A clarification technology used by municipalities to produce high-quality drinking water, polish sewage treatment plant effluent and handle combined sewer overflows has recently found new applications in the mines and iron and steel industry. This patented process, known as ACTIFLO®, utilizes microsand in a ballasted flocculation process to enhance the settling characteristics of suspended solids, increasing the efficiency sufficiently to achieve a clarifier footprint that is smaller than the one of a conventional clarifier. ACTIFLO® rise rates vary from 40 to 170 m/h with a total system hydraulic retention time of about 10 minutes. The result is a clarification system so compact that a full-scale system can operate as a trailer-mounted unit for temporary applications or as a permanent installation in facilities with space limitations. This paper explains the process and presents case studies in which this innovative technology was used at mines and steelmaking facilities to meet compliance requirements.

Feb 1, 2008

By A. Khan, C. Ciriello, W. Oliveira

"The purpose of this paper is to demonstrate the value of Operational Readiness (OR) in the successful delivery of capital projects. OR can be captured using several technical and practical definitions:• To ensure that the capital project being delivered is capable of an effective start up, ramp-up as planned and a sustainable productive operation.• To function as intended when started, with the appropriate people able to run it.• To increase the value in delivering the product/service through established systems, processes and procedures, while simultaneously minimize risk to both the project and the business.Historically, mining and metallurgical capital projects concentrate efforts on cost and scheduling during the implementation and design phases. The completion and subsequent handover of the operational unit is the main objective.When reviewing the mining and metallurgical industry’s capital projects, it seems many poor results and errors in terms of project design and ramp-up are self-inflicted, with the project neglecting to account for key aspects of the future operational plant. Interestingly, if the problems for the future plant occur during project implementation, they can be prevented during the project phase. It is required to connect the operational knowledge with the project in order to ensure an effective start up and operation.The benefits of OR will be shown to be applicable not only to mining capital projects but also to sustaining and business transformation projects. The paper also includes industrial examples showing both proper and improper use of OR techniques.The paper will cover 3 main areas of Operational Readiness: the OR model, OR related risk elements (i.e., risks associated specifically with the improper execution of OR) and conclude with OR specific case studies."

Jan 1, 2016

By D. Bois, F. P. Hassani, M. Hossein

"A growing environmental awareness hos prompted the mineral industry to seek innovations in waste management and technology. It is estimated that over 500 million metric tonnes of solid waste each year are rejected by the Canadian mineral industry. This waste hos to be disposed of in the most environmentally and economically acceptable manner.An extensive study has been conducted to estimate the cost of implementing total tailings fill from a waste disposal point-of-view as an alternative to large-scale surface disposal of tailings. The cost of waste disposal at the surface (tailings pond), and underground (total tailings fill) for three Canadian mines which have taken part in Quebec Mine Survey conducted in 1992 are analyzed. Surface disposal is the most economical and common method of mine waste disposal in Canada. Total tailings backfill as a method of waste disposal is technically feasible but cannot be regarded as more economic than surface disposal in all . It is important to remember that while surface disposal costs are rising, due to tighter legislation and more environmental pressure on governments; the costs of preparing and placing total tailings backfill is still falling as the technology improves."

Jan 1, 1994

By D. Moffat

Rio Algom Limited has mined uranium at Elliot Lake, Ontario for 20 years. The production of this energy-generating element results in the need to dispose of low-level radioactive solid wastes and liquid effluents. Because of the wet-temperate climate at Elliot Lake, the liquid effluents are of particular importance. Radium-226 is the isotope which requires most attention, and the current practice for its control is by addition of barium chloride and retention of the resultant precipitates in large settling ponds. Analyses of typical effluents and waste streams are discussed and typical levels of radium-226, thorium-230, thorium-232, thorium-228, lead-2iO, polonium-2iO, and uranium isotopes are presented.

Jan 1, 1979