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By G. D. Just

"Extensive mechanization of underground mining operations, improvements in blasting technology and the development of simulation models for systems evaluation has now made it feasible to optimize rock fragmentation and materials handling operations. Methods of achieving these objectives are described in this paper, with particular emphasis on the need to obtain precise field data measurements. Techniques are illustrated with reference to the sub-level open stoping system of mine production. IntroductionThe primary objective to be achieved in any mining system is to deliver a specified grade of ore to the mineral processing plant at a planned delivery rate and at the minimum total mining cost. Design and management of such a system is complicated by the large number of unit operations and the often unknown inter- relationships between the different unit processes. This particularly applies in underground mines, where planning restrictions and unit costs are much greater than in comparable tonnage sur face mining operations. These difficulties can often be resolved by the application of judgment based on extensive experience, but the costly trial -and-error methods required for new technology discourage innovation.Most modern medium- and large-scale mines are now extensively mechanized. Consequently, the performance of each unit operation by individual items of equipment should be predictable for a given set of conditions. An essential prerequisite is that quantitative performance data are available from field measurements. Such information can then be used to optimize the design and management of the complete mining system to achieve the minimum tot al mining cost. One of the most significant factors influencing all unit costs is the degree of rock fragmentation. The importance of this variable is indicated by the fact that opt imization of rock fragmentation implies minimization of tot al mining system costs."

Jan 1, 1980

By Denghong Wang

Abstract- The Ashele Cu-Zn deposit is a recently discovered volcanogenic massive sulfide deposit in Xinjiang, China, hosted by Lower to Middle Devonian submarine bimodal volcanic rocks. The primary ores of this polygenetic deposit are represented by massive syn-depositional pyrite, chalcopyrite, and sphalerite, and were formed by submarine exhalation. Hydrothermal alteration consists of strong sericitization, chloritization, silicification, and carbonatization of the metavolcanic rocks beneath the massive orebodies. Depletion of Na2O is an obvious chemical change in the hydrothermal halo. Geological and geochemical evidence suggest that the Ashele Cu-Zn massive sulfide deposit was formed by submarine exhalation related to bimodal volcanic rocks, trapped in a rifting basin, then deformed by shearing, and thermally metamorphosed by the intrusion of dacitic porphyry. Sulfur and lead isotopic studies indicate that metals such as copper and zinc may have originated from spilites, but that volatile components, especially sulfur, were derived directly from submarine volcanic magmas.

Jan 1, 1999

By Longjiang Li, Song Mao, Zhengyang Qiao, Qin Zhang, Guizhou University, Ling Wang

"After a study on the advantages and disadvantages of flotation column, according to the limitation of ordinary flotation column only is used for a flotation of microgranular minerals, the paper designed a new kind of layered convection coarse particle flotation column.Using a bauxite to test the rationality of the flotation column.The test results show that the new layered convection coarse particle flotation column is feasible.It has certain advantages about coarse particles flotation.INTRODUCTIONFlotation column has many advantages, for example,a simple structure, high efficiency and energy saving, the obvious advantage of fine particles flotation , the index superior and so on. The advantages gradually getting people's recognition. Research of flotation column has been a breakthrough, however, due to it only is used for the flotation of microgranular minerals, and the microgranular mineral particles will lead to a series of problems, and makes the processing cost is increased. Due to increase grinding fineness can save the grinding time and reduce the cost of grinding, also can avoid the disadvantage of fairly granular mineral particles cause a deterioration in the flotation. So it is necessary to research a kind of coarse particle flotation column.After a research on the advantages and disadvantages of flotation column, the authors designed and manufactured a new layered convection coarse particle flotation column, the flotation column both in theory and operation is better than flotation machine.DESIGN OF THE LAYERED CONVECTION COARSE PARTICLE FLOTATION COLUMNAdvantages and Disadvantages of the Traditional Flotation ColumnIn the field of mineral processing, as the increasing proportion of ore that has low grade, fine dissemination size, complex mineral composition characteristics. The limitations of traditional flotation machine is increasing[1],for instance, the high energy consumption, severe wear, inconvenient configuration , large amount of maintenance and so on. Compared with flotation machine, the flotation column with high separation efficiency, low investment and production cost, covers a less area low installation cost, less reagent dosage, more suitable for separation of fine particles and can automatically control, etc[2]. At present, the ore is facing the world energy crisis situation, and becoming increasingly difficult to flotation. So it is important to invent a coarse particle flotation column."

Jan 1, 2016

By F. Logsch, H. Pempel, J. Markowski, P. Ay

"Due to the European Directive 2000/53/EC on end-of-life-vehicles, from 2015 on more than 95% of car materials have to be recycled. In order to recycle the materials back into the economic cycle, it is necessary to produce products with high quality and purity.Plastic components in cars, which are coated with metals by vapour deposition or electroplating, have a wide circulation (e.g., as cladding panel or trim strip for interiors and exteriors). In the end-of-lifevehicle recycling process, these plastic-metal composites are not considered in usual technologies (car shredder) and are not separated from Automotive Shredder Residue. These parts can be separated by optical or HF-detection sorting and then introduced to a specific treatment.Experiments with a specially developed bioleaching configuration showed that the thin coatings, which consist mainly of copper, nickel and chromium, can be removed efficiently from the polymer base materials by a bioleaching solution with Acidothiobacillus ferrooxidans as a leaching agent. The solution used was produced in special fermenters with a 9K-nutrient salt media. During the bioleaching process at 35°C maximum temperature, most of the copper is dissolved and the other metals accumulate as metal sludge. The bacterial cultures based on A. ferrooxidans are robust and resilient.After a 48-hour bioleaching period while the composites were stirred regularly with ventilation, the plastic particles were completely free from metallic coatings. The metal components are separated for further use: undissolved components (mainly Ni and Cr) are separated by decantation of the solution; dissolved copper recovey is carried out by cementation of copper. The cementated solid contains ~98% Cu, along with small amounts of other metals.With the bioleaching process, good separation and re-utilization of the metallic coatings is possible. The cleaned plastic parts were prepared by compounding for new applications with injectionmoulding."

Jan 1, 2016

By Arthur A. Cole

Although the metal silver has been known and prized from very ancient times, it is in the New World that the greatest silver camps have been found. This is shown in the following comparison: [] For the last few years, the World's annual production of silver has averaged about 240 million ounces troy. Of this total, the North American Continent contributes approximately three quarters, Mexico leading with 38 per cent, followed by the United States with 27 per cent, and Canada with nearly 9 per cent.[] Of the largest silver producers in Canada, the Sullivan takes first place. Although primarily famous as a lead and zinc mine, it produced, in 1926, more than 4.5 million ounces of silver. The Premier mine, in northern British Columbia, produced more than 3 million ounces. In Ontario, the largest producers in 1926 were the Nipissing mine, .with 1.9 million ounces, and the Keeley mine, with 1. 7 million ounces. The Mining Corporation produced 1.1 million ounces from mines in the Cobalt district proper, and an equal amount in South Lorrain; while from the Castle-Trethewey mine, in Gowganda, there was an output of slightly less than one million ounces.

Jan 1, 1927

By Matt Manson

?? Current Exploration and Assessment ?? Overview of Potential Development ?? Infrastructure ?? Opportunities and Challenges ?? Renard? 1-10 kimberlite pipes and ?Lynx-Hibou? kimberlite dyke system within ?Foxtrot? property ?? 50/50 Joint Venture between Ashton (a subsidiary of Stornoway) and SOQUEM ?? Discovered 2001-2003 ?? Québec is routinely assessed as one of the top mining jurisdictions in the world ?? Agnico-Eagle Mines Ltd. Is Stornoway?s largest shareholder and a leading mine developer in Québec

May 1, 2008

By Shengwu Song, Xuemin Feng

Jinping I hydropower station is located in Sichuan Province in Southwest China. It is built on the Yalong River as a controlling cascade hydropower station in the middle and lower reaches, with power generation as its major function. Jinping I arch dam concerns many engineering issues and has attracted worldwide attentions due to its huge scale and unique settings. It is one of the most challenging projects in China with its 305 meters high arch dam and complex geological conditions for construction, including large-scale tectonic faults, intensively unloaded rock masses and geological asymmetry in its foundation. At present, the concrete arch dam construction has been completed and preliminarily impounded, most of the foundation treatments have been implemented, and four of six generator units had been put into operation in July 2014. In this paper, the analytical methods, design concepts, treatment measures and technical features of strengthening the geological defects in the dam foundation will be presented. Upon geological investigation into the dam foundation, a few large-scale weak discontinuities are observed. The rock masses in the left dam foundation are intensively unloaded, approximately to the horizontal depth of 150–300 m. These serious geological defects lead to a geological asymmetry on the left and right banks, and thus some major difficulties of dam construction are encountered. The influences of geological defects on the dam construction and safety are analyzed comprehensively, followed by the concepts and methods of treatment design. Based on this, the treatment methods of the weak rock masses and discontinuities are carefully determined by numerical analysis and scheme optimization, including the concrete cushion, concrete replacement grids, drainage system, anti-seepage curtains and consolidation grouting, which work together to enhance the strength and integrity of the dam foundation. Evaluations and calibrations through geo-mechanical model tests in combination with field monitoring results in early impoundment period show that the arch dam and its foundation are generally stable and function normally, which suggests that the research methods and treatment design schemes are reasonable and effective. The proposed treatment methods and concepts in the context are helpful for similar complex rock projects.

Jan 1, 2015

By John Campbell, William Trahant

"Total Quality Management (TQM) is becoming a reality in the mining industry. Widely adopted in the manufacturing and services industries, TQM has become the operating style of choice in numerous mining companies across the Americas and Australia. Iron Ore Company of Canada, Inco, MSA, Graniterock, Magma Copper, and CRA's Hamersly Iron - all are pioneers of TQM. These companies and others are confronting the challenges of implementing TQM and are managing the changes required of their people and cultures. What these companies are doing, why they are doing it, and how they are successfully managing the changes are the subjects of this paper.Driving the need for change in these organizations are a host of issues, some of which all mining companies are facing. Requirements from customers for ISO 9000 certification is becoming one of the initial motivators for Total Quality Management. These standards, commonly used in manufacturing throughout the European Community (EC), emphasize quality in the processes that create outputs, instead of just the outputs themselves. Iron Ore Company of Canada, for instance, responding to the requirement of one of its customers, British Steel, has become one of the first mining companies to meet the quality standard. Suppliers who meet the standards are highly desirable to customers who are themselves operating under the ISO or their national quality guidelines."

Jan 1, 1995

By R. Lovat, J. A. Hunter

"The design, development, and verification of the Lovat 7.6metre diameter full-face tunnel-boring machine is reviewed. Programmatic and technical challenges are outlined with a review of the specifications and the design to meet these requirements. Subsystem designs are presented for the waste material removal, ventilation, cutter head, structural support, advance technique, water removal, and interfaces with the Donkin-Morien Mine. The techniques used to verify that the design meets the requirements is by testing in the Lovat factory and in the field. Certification of the machine for use in a methane environment is discussed.IntroductionStudies have concluded that the average annual worldwide tunnel construction is 500 kilometres at an estimated average co st of $3,400 U.S . per linear metre. The total market value of the tunnelling industry is estimated as approximately $1.7 billion U.S. per annum. Of this, the current market for tunnelboring machine excavation is approximately $270 million U.S. per annum worldwide with a further potential of $250 million if more contractors are convinced that Tunnel-Boring Machines (TBM) are more suitable than conventional techniques. The worldwide civil tunnelling market has the potential to double each year in the next 5 to 15 years. Growth has been identified in the energy and mineral resources sectors of the economies of many nations and a significant volume of machine tunnelling studies and trials are presently underway for the extraction of coal, uranium , heavy oil or oil sand fuels, metallic and non-metallic industrial minerals and base metal or rare earth ores. Further tunnel projects for regional transportation, waterpower, irrigation , high density urban transportation, storm water sewers and water supply purposes are continually being implemented with new concepts like military security facilities and underground storage schemes being considered.Lo vat Tunnel Equipment of Rexdale, Ontario, the only Canadian manufacturer of TBMs was incorporated in 1973 to manufacture so ft ground tunnel-boring machines to satisfy this growing market demand. Lovat has produced an average of 5 machines per annum during the period 1972 - 1982 and has established an international reputation for competitive costs, quality of construction, after-sales service, and reliability. As of June 1982 Lovat TBM's have been used to tunnel over 240 km in projects throughout the world."

Jan 1, 1984

By François Charette

High stress conditions in underground mines push the performance envelope of support systems to their limit. In weak rock masses these conditions lead to large deformation and breakdown of the rock material, while stress release events in hard rock mines can lead to sudden and usually violent rock and support failure. In typical support systems, a combination of different reinforcement and support mechanisms provide the required convergence control and retainment. These systems usually involve a multi-pass support installation. The advantages of a single pass support system are investigated and several bolting combinations are compared. Criteria for design are reviewed and new criteria are proposed to include cost and effectiveness in commonly used engineering approaches. Field observation and testing is used to illustrate the difference between the proposed approach and more conventional systems.

Nov 1, 2011

By Helen Morrison, Chris Staun, James Vaughan

"Mercury is introduced into the Bayer refining process as a trace element in bauxite. During the digestion stage, a portion of the mercury is extracted which partitions between the flash tank off-gas, vapour condensate and bauxite residue streams. A technology or treatment that stabilises mercury in the solid phase during digestion would prevent environmental management issues that may arise from the presence of mercury in condensate and non-condensable gases. This study examines the effect of process additives on the deportment of mercury under Bayer digestion conditions. Bauxite digestion experiments were conducted in batch autoclaves in the presence of additives. Process liquor was analysed for mercury content using a thermal desorption technique. Pyrite and copper hydroxide were evaluated for their suitability as additives.INTRODUCTIONMercury is an ancient metal characterised by electrochemical nobility, volatility, low solubility in water and a liquid state at room temperature (Holleman and Wiberg, 2001). The biogeochemical cycle of mercury is complex. Elemental mercury may enter the atmosphere due its volatility, where it can be transported long distances. After settling and adsorption to sediments, methylation is catalysed through microbial metabolism (Qureshi et al., 2009). Methylated mercury species are potent neurotoxins, and bioaccumulation of mercury is well documented, particularly in seafood (Kozin et al., 2013, Pan et al., 2014, Pollman, 2014). Environmental regulations for mercury emissions are becoming increasingly stringent (UNEP, 2015). Considerable research has already been performed and technologies developed for the remediation of mercury in wastewater and the trapping of mercury from industrial stack emissions. Wastewater technologies usually target ionised mercury using adsorbent, ion exchange and complexation mechanisms (Krishnan and Anirudhan, 2002, Li et al., 2015a, Chiarle et al., 2000), while stack emission technology is dominated by impregnated activated carbon adsorbents (Gao et al., 2013, Zheng et al., 2012). Related developments include piezoelectric amalgamating sensors for in line detection of gaseous elemental mercury in industrial stack emissions (Kabir et al., 2015, Sabri et al., 2011). There is a paucity of research regarding removal of mercury from the Bayer process."

Jan 1, 2016

By D. M. Slavich

"In today's operating and investment climate, project evaluation is both more important and more difficult. It is more important because economic and financial analyses of a proposed project provide a basis for judgment of a project's commercial viability by equity participants, lenders and, in some cases, other participants such as off takers and governments. It is more difficult because these analyses must, of necessity, be based on estimates, projections and evaluations which must be made in a period remarkable for its economic and political uncertainty.Project evaluation starts with the analysis of the engineering, commercial and financial information available. Beginning with the preliminary design and capital cost estimates, alternative financing plans can be developed outlining possible sources of funds, terms and security arrangements. Pro-forma financial statements can also be developed, including sources and uses of funds, cash flow schedules, income statements and balance sheets. With these results, various profitability measures can be determined.Subsequently, in an effort to deal with uncertainty, these results can be tested by measuring the impact on project viability and profitability of changes in project and external variables such as product process, mining and processing rates, operating and financing costs, currency exchange rates and other factors.The results are a number of financial projections reflecting different assumptions for key project parameters. The projections can be used to structure the project to achieve the maximum financial performance. Projects, the financial viability and profitability of which can be demonstrated under varying market conditions, will be the most competitive in capital markets."

Jan 1, 1982

By S. Banisi, J. Marois, A. R. Laplante

"This paper compares the behaviour of gold and ore in the grinding circuit of Hemlo Mines Ltd. Particular attention is given to grinding kinetics, classification behaviour, and liberation. For grinding kinetics, laboratory grinding of gold flakes and silica, 840 µm to 1200 µm in size (14/20 mesh), was also performed to provide a standard for comparison and to study in a controlled environment the mechanisms of breakage, folding , smearing and impacting.Grinding kinetics were characterized at laboratory scale with breakage and selection functions. The breakage function showed that 75% of gold disappearing from the 840 µm to 1200 µm class reported to the 600 µm to 840 µm; this figure is much higher than for silica (46%) or most other minerals, and implies that comparatively fewer fine fragments are produced from the breakage of gold flakes, on account of gold's malleability. The selection function of silica was four times that of gold. At plant scale, the ratio of the selection function of ore and gold increased from 6 for at 50 urn to JOO pm to 20 at 500 um to 1000µm.Observation of original flakes and their fragments with the scanning electron microscope showed that the main mechanism of ""grinding"" from the 840 µm to 1200 µm to the 600 µm to 840 µm class was folding rather than actual breakage. This was confirmed by a measure of individual flake weight. The postulated breakage cycle is that relatively globular flakes become increasingly serrated through grinding; they can then regain their original shape through folding and reflattening into cylindrical and spherical shapes, as the majority does; however, some fragments will at this point undergo actual breakage. Photograhic evidence is presented to support the proposed mechanisms.Smearing of gold unto silica was observed when silica was ground after a gold, and embedding of silica into gold flakes when gold was ground after a silica. Both mechanisms occur whenever gold and harder minerals are jointly ground, and result in ""unliberation"" of gold. It is postulated that smearing of gold onto other minerals plays an important role in explaining how gravity recovery can increase over-all gold metallurgy, especially when used ahead of flotation.Classification of gold in the primary hydro cyclones takes place at a much finer cut-size than ore, 20 µm vs 57 µm. This and the slower grinding kinetics result in high gold circulating loads in the primary loop, 6700%, and a gold content in the primary cyclone underflow (PCUF) is twenty-four times that of the ore. The gold size distribution for primary cyclone overflow is much finer than that of the ore, although they are essentially similar in the PCUF.Liberation, or more accurately ""gravity recoverability"", was assessed with a 7.5 cm (3 in.) Knelson concentrator. It varied between the thirties for the primary mill discharge and two cyclone overflows, to highs of 89% and 92% for the PCUF and secondary mill discharge."

Jan 1, 1991

By J. L. Barton, R. A. Murray

"This paper looks at how Syncrude Canada Ltd. is utilizing the Conveyor Belt Monitoring technology developed and patented by the Australian CSIRO and licensed to Syncrude by Conveyor Belt Monitoring of North America, Inc. The technology involves magnetizing the steel cables in the conveyor belts and detecting the fields produced by breaks, gaps or cable ends using special sensors which feed the signals into a multi- channel recorder to provide permanent traces of the various events taking place in the steel cable belts.The data is analyzed and combined with existing belt audit programs, to assist in predicting belt life, change-out criteria and belt design, belt loading and construction. All of these applications of the CBM technology leads to better utilization of resources and forms an integral part of the conveying system reliability program."

Jan 1, 1992

By A. Brown

IN INTRODUCING the subject of rock pressures, it may safely be assumed that mining men are only too familiar with the physical effects of strata stresses that accompany the extraction of minerals. It may be further assumed that they have, as individuals, arrived at certain conclusions regarding their nature, based upon years spent in observing such phenomena and in learning how to continue mining in spite of them. Such hardly won experience forms the core of what is often referred to as 'pit sense'. This essential type of knowledge is not ?based on theoretical considerations, nor can it be found in text books. It is highly individualistic in nature and almost impossible to pass on from one generation to another in terms of precise rules for guidance. It is this aspect of individual judgment based on practical experience that has led to the significant phrase The Art of Mining.

Jan 1, 1956

By John W. Korczak

The use of geological and grade block models has been standard practice in mine design for many years now, with a wide range of software available for creation and analysis. Although geotechnical parameters are of vital importance to mine planning there is very little in the way of commercially available systems for integrating geotechnical data into the mine planning and design process. Sirovision is a new technology developed by the CSIRO (Commonwealth Scientific and Industrial Research Organization) in Australia for automated, safe and accurate 3D mapping of geological and geotechnical features. Datamine has integrated this capability into its product range so that Sirovision has become an integral part of the day-to-day mapping, mine geology and geological / geotechnical modeling in both open pit and underground mine environments. This is the first integrated underground application of Sirovision from Datamine collaboration with Xstrata Nickel at the Nickel Rim South Project. This paper discusses the role of Sirovision in collecting the raw data required for geological and geotechnical analysis and the interpretation in a quick, safe, auditable and reproducible manner.

May 1, 2009

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 Hugh K. Taylor

"With some justification, people have long complained about the indefinition of ore reserves. Perhaps they were led to expect too much; from former and easier definition practices in the once common underground mines with exposed and available assets, where the obsolete term 'ore in sight' was at least partly literal. But such mines have become rarer, and their underground development less affordable. For most projects, valuations and its definitions have thus been advanced from actual to prospective mines, leaving a very wide gulf between 'what is there' and 'what may happen to it'. This brings the double challenges of reduced geological and technical assurance and the protraction of economic uncertainties.This paper avoids the popular field of regional resources, being confined to what may possibly be mined within single or closely grouped deposits. For these, many estimates of tonnage and grade must be made, defined and declared long before assessment of feasibility; and the uncertainties of the latter make it an unsound base for defining the earlier quantities. Despite the best of intentions, implied or inferred promises may proveimpossible to honour.A simpler framework of definitions is suggested, to some extent reverting to an earlier dependence on supporting work rather than on opinions of economic assurance or future events that are more properly the functions of production and cash flow schedules."

Jan 1, 1994

By T. Gerritsen, T. Plikas, K. Ochoa, M. Loveless, R. MacRosty, J. Reichart, R. Pula

Sidewall accretion in a smelting furnace plays an important role in furnace integrity as it provides protection to the sidewall cooling elements and thereby extends the furnace campaign life. The extreme thermal and mechanical stresses in the furnace and changes in the slag chemistry can cause the sidewall accretion to melt or break away decreasing the lining protecting the cooling elements. Thin accretion is highly undesirable as it increases the risk of exposing the cooling elements to the molten bath and in the worst case may lead to a failure. Therefore, monitoring the sidewall accretion on an operating furnace is extremely important to manage furnace integrity and to support safe furnace operation. Operators often generate estimates for sidewall accretion and refractory thickness using either copper cooler temperatures or heat load into the cooling water circuits. Multivariate statistical models, on the other hand, have the capability to consider all the process measurements simultaneously to provide a more reliable estimate. This paper describes the application of multivariate statistical models for sidewall integrity monitoring on a Flash Converting Furnace (FCF) and also discusses the online implementation of these models as the Sidewall Accretion Monitoring System. INTRODUCTION Rio Tinto’s Kennecott Utah Copper (KUC) smelter located near Salt Lake city, Utah operates a Flash Smelting Furnace (FSF) and a Flash Converting Furnace (FCF) to produce high-grade matte and blister copper respectively. Since the commissioning of smelter in 1995, several improvements were made to these furnaces to increase their efficiency and operational safety. At present, Kennecott smelter is known to be among the lowest-emission and highest energy recovery copper smelters in the world. Since the smelter start-up, Kennecott has invested in several advanced furnace monitoring practices to evaluate the integrity of the furnaces and improve their campaign life. An example is their temperature monitoring system installed for the smelting and converting furnaces, which continuously monitors the furnace sidewall temperatures and notifies the operators during temperature excursions. During an investigation on the converting furnace, it was revealed that there were frequent temperature excursions in the settler sidewall area towards the reaction shaft end of the furnace that caused significant furnace downtime. The reason for the sidewall temperature excursions was not clearly known.

Jan 1, 2019

By Steve McMullan, Blaine Webster, Ian Johnson, Ron Matthews

"Time domain spectral Induced Polarization (IP) data from the Tower, Jojay and Laurel Lake gold deposits in northern Saskatchewan are presented. The resistivity data shows both resistivity lows (due to fault, shear or alteration zones) and resistivity highs (due to silicification) in the area of the deposits. The high resistivity zones suppress and distort coincident IP responses, calling f or high quality surveys and special care in interpreting the IP data.Electromagnetic methods are not effective in locating the deposits. This is due, in part, to masking by conductive cover. The Jojay Lake deposit has a strong magnetic response. A more indirect magnetic association is seen for the Tower Lake deposit. The Laurel Lake deposit has no magnetic signature. Magnetic data are useful in defining structure in all cases.All three deposits are outlined in the IP survey results. IP anomaly amplitudes from the pole-dipole array are from two times (Tower and Laurel Lak e) to six times (Jojay Lake) background values. Gradient array IP anomalies are of less amplitude. The spectral time constant is short for the Tower and Laurel Lak e deposits and long for the Jojay deposit. This implies that the metallic sulphides in the Jojay deposit are more interconnected than those of the other two deposits. INTRODUCTIONInduced polarization / resistivity surveys are commonly used in gold exploration program s in the Canadian shield because the IP method is effective in detecting disseminated metallic sulphides which are often found associated with gold. Other common geophysical sur vey methods such as magnetics, VLF and EM are not generally capable of direct detection of disseminated sulphides. Since the introduction of the IP method in the 1950s, it has undergone continuous improvement. The most recent improvement is the development of time domain receiver s which sample the full de cay and record it in digit al form. This results in a more complete measurement of the response which permits analysis and enhancement of data quality and the derivation of a nomaly parameters which characterize the measured decay. This extension of conventional time domain IP methods is called spectra l IP, a term first introduced by Pelton et al. working in the frequency domain Spectral IP surveys are attractive because they allow the possibility of discriminating between IP responses which have similar amplitudes but are due to dissimilar geo logic targets. The discrimination can be important in the selection of IP anomalies for follow-up.Time domain spectral IP survey results are presented over three known gold deposits in northern Saskatchewan-Tower Lake, Jojay Lake and Laurel Lake. The surveys were initiated and supported by Cameco-A Canadian Mining and Energy Corporation (formerly the Saskatchewan Mining and Development Corporation-SMDC) and were carried out by JVX Limited using the Scintrex IPR-II receiver and attendant spectral analysis software."

Jan 1, 1989