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By P. E. Cavanagh

Abstract Many investigators have been interested in developing some non-destructive method for detecting or determining the changes in physical properties in steel occurring during endurance tests or normal service life of a part which fails in fatigue. This paper presents a broad discussion of some of this work and the possibilities of developing useful test procedures based on some of the information obtained in the past. Changes in magnetic properties, electrical resistance, damping capacity, X-ray diffraction patterns, and remaining fatigue life at load different from service load have all been investigated as possible means for following the sequence of events during fatigue failure. In some special instances, tests such as these may be used to predict fatigue failure. As an in stance of practical application of the continuous determination of changes in magnetic properties during fatigue, a brief account is given of work done in non-destructive inspection of mine hoist-rope. As a result of extensive experiments and field crisis, it has been found possible to detect the beginnings of failure in a wire rope in service. The test method used will detect plastic deformation in a wire rope, no matter what its cause. There is no possibility of determining the remaining useful life of a rope by calibrating changes in magnetic properties in terms of remaining fatigue life. A change in magnetic properties at a point in a rope may indicate a decrease or increase in fatigue life, depending on the overload history of the rope. A continuing change in magnetic properties ac a point, however, does reliably indicate a developing weak point which will eventually lead to failure. The important point about any change in magnetic properties is not the magnitude of the change, but whether or not it continues.

Jan 1, 1947

By Joel Werner

Weak metal prices, declining head grade, and increased operational costs are forcing many open pit mining companies to look to their balance sheets for significant cost reductions in order to remain competitive. Maintenance continues to represent a significant proportion of the total operating costs in the mining industry. Compared with the other major cost components of the mining process very little effort has gone into maintenance optimization. The potential payoff from maintenance optimization on the cash cost of the commodity is enormous. A large percentage of these costs are incurred in unscheduled maintenance events, which typically cause serious disruptions to the production process. These maintenance induced production losses can be a significant contributor to the overall operating costs. A structured proactive maintenance approach using the latest advances in technology can achieve dramatic cost reductions and productivity improvements. Remote condition monitoring systems are becoming increasingly commonplace and have the potential to identify problems prior to failure. Detection of equipment degradation prior to failure will enable repairs to be scheduled thereby reducing costs and interruptions to production. Remote condition monitoring technology has evolved rapidly in recent years, with a host of new tools becoming available to assist mine operators in improving their maintenance operations. These tools have capabilities such as: remote real-time vital signs and performance monitoring, alarm/event handling, trend analysis, and maintenance workflow management. When these monitoring tools are used in conjunction with a mine management system the vital signs data can be integrated and associated with maintenance history, predictive maintenance data, operational information, and geographical information. This integrated approach to the management of vital maintenance data will help shift the mobile equipment maintenance paradigm from reactive to proactive. This paper will introduce a proactive approach to the management of the maintenance process and the tools required to facilitate this process.

May 1, 2003

By Forrest A. Kerr

The subject of the Coast Range batholith and its eastern contact zone needs no introduction to British Columbia mining men. Because of its reputed potentialities, this zone has aroused much interest. Because it has touched the pockets of the people by actually producing dividend-paying mines, it has been able, more particularly in certain isolated sections, to retain and accentuate that interest. However, the Stikine River section of the zone has never had the good fortune to have a mine developed, which, through profits or lack of profits, could create such interest. The Cassiar district, beyond the Stikine River area, has been a lure to the prospector for over half a century and was still strong enough in the last few years to attract close to a million dollars in capital and labour. All of this has passed through the Stikine river area, has looked at it, and ignored it. Sufficient interest has never been aroused in the area to bring forth an effort to see what is there, in spite of the fact that it belongs to the same zone in which some of our richest mining camps are located. Because the contact zone of the Coast Range batholith has long been recognized as an ore producer of considerable potentiality, the Geological Survey some years ago formulated a plan to map as much of this area as possible in order to assist in promoting its development. This plan has been furthered during the last fifteen years whenever opportunity presented itself, until today a fairly large part of the area has been covered. The work which has been done on the Stikine during the last two years is the beginning on what is the largest remaining gap in the general plan.

Jan 1, 1928

By Osvaldo A. Bascur

Industrial complexes rely on measurements of flow rates, qualities, and concentrations for monitoring and optimizing their operation. Corporations use the data from the various sensors and measurements to make business decisions, which affect the profitability of the operation. However, gross errors, due to a variety of reasons like faulty sensors, bad instrument calibration, or incorrect process models may corrupt the actionable information supplied to operations, quality managers, and maintenance personnel. The solution is to use the sophisticated new tools to model the process, sift through the available data to locate the gross errors, and use statistical data reconciliation to validate the sensors and instruments. In this way the data are unified to give the most accurate plant information for use by the monitoring and decision making processes. Most mining and metallurgical plants use predictive maintenance policies based on statistical analysis and special techniques, like vibration analysis, and oil and lube analysis for critical equipment. Process control strategies are installed in several metallurgical sites. All of these depend on reliable and accurate data. The data unification methods validate the individual measurements by using the concept of balances and statistical techniques where each instrument is no longer independent of the other measurements in the facility. This paper refers to the data unification and analysis methods required for profitable plant operations. Continuous improvement and monitoring of the measurement system at the plant and analysis of the reconciled data provide the best information for the decision-making process. On-line gross error detection and elimination methods are required to ensure efficient evaluation of process performance and process optimization. An open discussion of the new methods for gross error detection and data unification will be presented.

May 1, 2001

By Robert B. Parsons

"This article is based on a paper presented by Jim Scott at the 1988 annual convention of the Prospectors and Developers Association of Canada. The paper suggests a number of factors that might be taken into account in negotiating royalty terms.IntroductionRoyal ties are a part of mining life in Canada. They are used by many kinds of individuals in many kind s of situations. Prospectors commonly take royalty interests back when they transfer claims to development companies. Mining companies disposing of undeveloped (or sometimes even developed) properties are often paid at least in part by royalties. Royalties are even used by institutional investors with no other connection with the resource industry.Such different royalty holders have different investment goals, different cash flow requirements, and different risk / return preferences. These differences have given rise to a number of different royalty type s. These types range from the simplest cents-per-ton royalty (where the operator pays a royalty at a fixed rate per ton milled) to net smelter return or ""NSR"" royalties (where the royalty is based on a percentage of the operator's NSR) all the way to net profit interest or ""NPI"" royalties (where the royalty is based on the operator's bottom-line net profit),The fundamental difference between the many royalty types is in the risk/ return relationship. The cents-per-ton royalty, for example, is relatively risk-free. Of the many economic factors which affect a mine, the only one which will affect the royalty holder is the amount of ore physically milled. On the other hand, the potential for significant gains under a cents-per-ton royalty is also very limited. The royalty holder will not share in any increases in the market price of the end product or any cost reductions achieved by the producer."

Jan 1, 1988

By Robert B. Parsons

"This article is based on a paper presented by Jim Scott at the 1988 annual convention of the Prospectors and Developers Association of Canada. The paper suggests a number of factors that might be taken into account in negotiating royalty terms.IntroductionRoyal ties are a part of mining life in Canada. They are used by many kinds of individuals in many kind s of situations. Prospectors commonly take royalty interests back when they transfer claims to development companies. Mining companies disposing of undeveloped (or sometimes even developed) properties are often paid at least in part by royalties. Royalties are even used by institutional investors with no other connection with the resource industry.Such different royalty holders have different investment goals, different cash flow requirements, and different risk / return preferences. These differences have given rise to a number of different royalty types. These types range from the simplest cents-per-ton royalty (where the operator pays a royalty at a fixed rate per ton milled) to net smelter return or ""NSR"" royalties (where the royalty is based on a percentage of the operator's NSR) all the way to net profit interest or ""NPI"" royalties (where the royalty is based on the operator's bottom-line net profit),The fundamental difference between the many royalty types is in the risk / return relationship. The cents-per-ton royalty, for example, is relatively risk-free. Of the many economic factors which affect a mine, the only one which will affect the royalty holder is the amount of ore physically milled. On the other hand, the potential for significant gains under a cents-per-ton royalty is also very limited. The royalty holder will not share in any increases in the market price of the end product or any cost reductions achieved by the producer."

Jan 1, 1989

By D. A. MacFadyen, J. J. Brummer, C. C. Pegg

The early identification of a kimberlite dyke and the occurrence of pyrope garnet grains along a section of the Munro Esker north of Kirkland Lake encouraged the search for kimberlites. Subsequent exploration using data from aeromagnetic surveys completed for the Kirkland Lake Initiatives Program (KLIP) resulted in the discovery of five kimberlite diatremes in the area north of Kirkland Lake and another one to the south. These are only a portion of the cluster of pipes found so far that probably occur in the area. Recovery of the diamonds present in four of the pipes yielded 16 stones, the largest being 0.17 carats. Unfortunately evaluation of the pipes is a problem due to the cover of glacial drift, up to 92 m in thickness, which makes it difficult to obtain an adequate bulk sample. A study of their ages, mostly from drill hole samples, suggest that the kimberlite diatremes and other alkaline ultramafic rocks were emplaced along a northwesterly zone of rift structures. These alkaline ultramafic rocks cut across all earlier rock types and have ages ranging from 121 Ma to 173 Ma. The zone of deformation, along which these rocks occur, has been named the Lake Timiskaming Structural Zone (LTSZ), a modification of Lake Timiskaming Rift Valley (LTRV). Ultramafic intrusions which were emplaced along the LTSZ can be traced from the James Bay Lowlands in the northwest to past Belleville on the north shore of Lake Ontario in the southeast, a distance of about 1070 km. As the emplacement of these rock types become known more are certain to be found by drilling selected aeromagnetic anomalies. The project has demonstrated that aeromagnetic surveys can be used successfully to identify covered kimberlite targets.

Jan 1, 1992

By Robert B. Parsons

"The budget that was tabled by Finance Minister MacEachen on November 12, 1981 will result in a major tax reform of Canada's income and sales tax systems, the likes of which have not been witnessed by taxpayers since 1971. All segments of the economy will be affected one way or another by the far-reaching budget proposals; the mining industry did not escape untouched.Important changes will be introduced which will alter some of the fundamentals of structuring mineral resource ventures in Canada. This month, Tax Notes examines these changes, and also summarizes the other highlights of this key federal budget.IntroductionFinance Minister MacEachen's budget, with its lower personal tax rates, loophole plugging and tax shelter bashing, represents the biggest shakeup in our tax system since tax reform in 1971. In his budget, presented in the House of Commons on November 12, Mr. MacEachen proposed substantially lower tax rates for middle and upper income individuals, with the top federal and provincial tax rate dropping to about 50%, but in return he eliminated most of the opportunities for individuals, and corporations, to reduce or defer taxes through a wide variety of tax shelter and tax planning mechanisms.Although many of those budget proposals that dealt with the resource industries focused on the implementation of the September 1, 1981 agreement reached by the federal and Alberta governments concerning the National Energy Program (see Tax Notes in the December 1981 issue of the Bulletin), the budget also contained some proposed amendments that would have significant implications for investment in the mining industry.This month, Tax Notes examines these latter proposals, and also summarizes very briefly those budget proposals which are not unique to the resource sector."

Jan 1, 1982

By Ryan W. Siggelkow

Mines today use various methods of mining to extract ore. Because of the dangerous nature of many of these processes, remotely controlled LHD machines are being used to extract the ore from the draw point. The remote control system, although being made safer all the time, has remained virtually unchanged for many years. The basic functionality is an operator switching the machine to remote control, getting out of the cab, walking up a stand, operating remotely, returning to the cab, switching to manual, driving manually, switching to remote, and switching to manual. It seems repetitive, and time consuming, does it not? Networking, convergence, video, voice, and data infrastructures, and other technologies are growing by leaps and bounds in virtually every industry and region, except for mining. From the comfort of the living room couch, a Canadian can play hockey online with full voice conversations over the Internet with someone in Russia in real time. Yet, a mine superintendent must jump through hoops to have a private conversation with the front line supervisor underground. "Is Joe around anywhere?" If Joe hears the message, he will respond. If not, who knows? Maybe he's hurt. Maybe he's not. Where is Joe? Nobody really knows, and that is scary. Today, surface knows that the workers disappeared into the cage at 7:00 a.m. They also know that the workers will probably and hopefully return at 3:00 p.m. Is there not a better way to handle this? With such a complex industry, it seems as if, for the most part, the introduction of new technology into mining has either been overlooked or has been met with some resistance. It is time to step back, look at the process, and see how it can be improved. Key areas of focus will be safety, productivity, dependability, and cost-effectiveness.

Oct 1, 2010

By John Clancy, Andrew J. Freyman

"Trends in world coal markets indicate that the next twenty years could be a period of intensive development for British Columbia's coal resource. This paper examines demand projections for metallurgical, thermal and chemical feedstock coals, with particular reference to domestic and Pacific Rim markets. Supply possibilities, from the point of view of British Columbia's competitive position, are explored, with emphasis on the interaction of such factors as capital, labour, port and transportation requirements.The paper concludes with an examination of British Columbia's strategies in light of the foregoing, and comments on the government's role in ensuring that development of the coal resource be attained in a manner consistent with over-all provincial goals and objectives.IntroductionFor the purposes of this paper the Pacific Rim is defined as including, in addition to Canada, the following: Japan, Korea, the People 's Republic of China, Hong Kong, Taiwan, the countries of the Indonesian Archipelago, Australia, New Zealand and the Pacific-bordering countries of South America and Mexico. The United States has been excluded in this definition in order to better illustrate the economic growth potential for British Columbia coal in the Pacific Rim economies.In the past decade, the Pacific Rim economies have grown faster than most other economies in the rest of the world; economic growth rates of 10 per cent were common in the region prior to the 1974 slowdown and the average rate of economic expansion in the mid-1970s has exceeded 6 per cent. Rapid expansion of international trade in the region has been a major stimulus in this process. By 1979, Pacific Rim two-way trade has reached an estimated $550 billion-about 20 per cent of world trade."

Jan 1, 1982

By William Petruk, Donald Leroux, Michael Cooper

"Brunswick's primary flotation circuit (CuPb) produces a low grade concentrate containing considerable amounts of undesirable sphalerite and pyrite. To determine the cause of the poor selectivity, a series of Quantitative Mineralogical Analyses (QMA) were performed on several CuPb circuit streams. It was observed that significant fractions of sphalerite and pyrite reporting to the concentrate was liberated, meaning that their depression was not complete. The study highlighted the need for some R&D efforts to be spent in sulphide flotation fundamentals.IntroductionThe viability of many mining projects strongly depends on the performance of their concentrators. More than ever, competitive grade concentrate and high metal recoveries are criteria of paramount economic importance. The selectivity of solid/solid separation processes used in concentrators must be maintained at high levels or continuously improved.Flotation is the solid/solid separation process used by most base metal producers. In spite of its low operating cost, flotation remains a very complex process. To make it selective, precise reagent dosages and electrochemical conditions must be maintained. The difficulty in controlling flotation lies in the numerous heterogeneous reactions that can take place between the different solid, liquid and gaseous phases involved. This complex chemistry makes flotation selectivity difficult to understand and, therefore, to improve from a theoretical point of view.Brunswick Mining and Smelting, near Bathurst N.B., operates a 10500 tpd concentrator which produces four concentrates through five stages of sequential flotation (Figure I). Various reagents are added at key process stages while the ore undergoes different electrochemical conditions. Although the selectivity is important at all stages, the performance of the very first separation, the CuPb circuit, is the most critical. It is here where mineral misplacement to the wrong stream has the greatest economic consequences."

Jan 1, 1996

By Y. Mercadier, M. Ait-Ali, M. Dostie

"This paper presents the results of an analytical study to assist in the design of blast furnace tuyeres, including a prediction of the heat transfer process.IntroductionA blast furnace tuyere must be made of a material which must con serve its geometric and structural integrity in the environment of the fire-ball of the furnace. It must be cooled by a fluid forced through its internal cavities in such way as to keep its maximum temperature below the allowable limit. The prediction of the convective heat transfer coefficient inside the tuyere is of great importance in the design of new tuyeres with increased service life. We have developed a computer program which can predict the convective heat transfer coefficient for two-phase flow. This paper shows how the program work s and how it can be used for the numerical simulation of tuyeres.To simulate the h eat transfer conditions in water-cooled tuyeres, one has to predict:a) The heat flux (radiation and convection) generated by the combustion gases. This was evaluated using the single-zone gas-furnace model. This model yields results which are of the right order of magnitude. A more fundamental study of radiation heat transfer based on combustion and gas concentration s will be reported in a future publication.b) The local convective heat transfer coefficient at all points with in the tuyere.Prediction of the Convective Heat Transfer CoefficientTo calculate the convective heat transfer coefficient for refrigerant stream, semi-empirical correlations developed by the nuclear industry were adopted. These correlations permit us to analyze the entire range of the convective boiling range, as shown in Table 1. Our first attempt, with a single-phase flow correlation, has shown the need to take nucleate boiling into account."

Jan 1, 1982

By Robert B. Parsons

"Although the April 19, 1983 federal budget appears to put greater emphasis on new or expanded government spending programs in an effort to get Canadians working again, the budget proposals contain a light sprinkling of tax changes which could be of some direct benefit to the mining industry.This month, Tax Notes examines some of the more important of these changes.IntroductionSome sectors of Canada's mining industry could benefit from the proposed income tax changes announced by Finance Minister Lalonde in delivering his budget address to the House of Commons on April 19, 1983. Improved depletion allowance rules, expanded investment tax credits, better use of business losses, and inflation proofing of personal capital gains on Canadian common shares are all part of the measures included in Mr. Lalonde's first budget to try to reinvigorate the battered Canadian economy.Improved DepletionUnder the Income Tax Regulations, a taxpayer who incurs Canadian exploration expense (and certain other eligible expenses) is permitted to deduct not only the full amount of the Canadian exploration expense (""CEE""), but also an additional allowance (the so-called earned depletion allowance) equal to one-third of the CEE. Thus, a taxpayer in certain circumstances can claim a deduction of $1.33 for each $1.00 of eligible expenditure, including CEE.Although CEE can be deducted from any source of the taxpayer's income (for example, from investment income, salary income, and so on), prior to budget date the earned depletion allowance was deductible only from the taxpayer's resource profits. This restriction on the deductibility of the earned depletion allowance substantially reduced the attraction of the allowance: few individual investors or investment companies, for example, have the required stream of resource profits, at least when the CEE or other eligible expenditure is made."

Jan 1, 1983

By L. C. Kitchener, K. Vollenwyoer

"This paper describes the development of an automated, 70-ton capacity, underground electric trolley truck at Inco Ltd. The purpose of the project is to provide a high capacity and high productivity haulage system to suit continuous loader applications in existing mining horizons where conveyor belt application is not immediately practical. IntroductionWith the start o f a program by Inco in mid-1983 to develop a continuous loader for bulk mining of our hardrock orebodies, the need for a rapid ore transportation system was recognized to match the increased extraction rates planned. Two methods were investigated, truck haulage and conveyor belt. As a result, a conveyor belt system has since been designed and installed with a continuous loader at Stobie Mine and an electric truck has been designed, fabricated and assembled, with shop testing underway. This paper deal s with the latter project. BackgroundMany existing mining horizons which could utilize continuous loaders do not have the straight runs required for conveyor belts. In these situations, truck haulage would be the only alternative of the other transportation methods that would be practical. In order to match the high productivity potential of the continuous loader, however, a more efficient trucking system is required than would be available with conventional diesel powered trucks or with electric truck designs commercially available, or under development. A higher capacity truck and an automated operation is necessary so that the application of additional units to suit increasing haulage distances matches loader output without reducing over-all productivity because of the need for additional operators.A first effort to work with a major electrical manufacturer was unsuccessful and resulted in a project delay of almost one year. In November 1984, an investigation into the concept was reinstigated with UTDC, and an agreement to start design was reached in April 1985."

Jan 1, 1988

By A. I. A. Salama, M. W. Mikhail, R. J. Mikula

"The Coal Research Laboratory (CRL) of CANMET along with other research organizations in coal-producing countries envisage major benefits from computer applications in coal preparation, Some of these benefits are greater system flexibility, improved coal preparation plant performance efficiency and efficient utilization of manpower, all of which result in economic benefits. Computers can be applied for both on-line and off-line purposes; this paper focuses on the on-line applications from the process control point of view.A critical discussion of the different analog and digital process control systems is presented. Recent developments in Great Britain, West Germany, Poland and Australia on automation and instrumentation using on-line measurements of coal ash and moisture contents are identified.The CRL research and development strategy aimed at achieving on-line computer control of an automated coal preparation plant is presented.IntroductionIn the past twenty years an enormous progress in the area of computer technology has been noticed. Computer applications in industrial processes offer greater system flexibility, improved plant performance efficiency and efficient utilization of manpower. Significant computer control development in mineral processing has already been achieved. Although progress has been made in the area of computer applications in coal preparation, more effort is needed to utilize the full potential.The computer applications in coal preparation can be viewed as off-line and on-line. Considerable progress has been reported in the area of off-line computer applications, especially in the areas of modelling, performance evaluation/prediction and statistical analysis. However, only modest progress in on-line applications has been reported(1-7). This paper will focus on: online instrumentation and process control applications, different analog and/or digital control systems, on-line automation and instrumentation in other countries and CRL strategy toward pilot plant automation."

Jan 1, 1985

By Gerhard W. Heinrich, Gerald V. Schroeder, Daniel A. Murphy, Daniel F. Suarez, Jamie B. Beauchamp

"Washwater 'Finger' sprays were installed and tested in the copper/nickel separation circuit at Strathcona Mill to improve flotation capacities and related metallurgical performances. The new spray design features submerged sideways introduction of wash water into the flotation froth through nozzles at the end of vertical pipes which are suspended from a header above the froth. This maximizes the effective cross sectional area of flotation vessels while maintaining effective froth cleaning and a desirably high density of the concentrate slurry. The plant tests gave increases of copper concentrate production rates of 17% to 20% for conventional cells and 16% to 20% in column flotation at target grades of 29% to 30% copper and of less than 0.5% nickel. Basic considerations and concepts of tests and evaluation procedures are described.IntroductionMeeting flotation concentrate grade targets at maximum production rates and recoveries is a challenge all too familiar to operators of base metal ore concentrators. Frothwashing is an option to improve grade/recovery performance by minimizing entrainment of impurities into the concentrate, which is commonly known since the sixties (Kaya & Laplante, 1989). It has been recommended for the flotation of sulphides and industrial minerals alike (Kaya & Laplante, 1989; Miller, 1969; Heinrich, 1989) and has found its ultimate application in flotation columns (Finch & Dobby, 1990). The washwater addition in a flotation column is most evenly distributed over the column's cross-sectional area thus ensuring almost complete displacement of feed water from the froth by a countercurrent washwater flow -provided, a positive bias is maintained. Therefore, flotation columns are ideal for cleaning flotation. However, there is usually less room for boosting the concentrate production capacity by increasing airflow or slurry level then with conventional cells because of the smaller cross-sectional area available."

Jan 1, 1994

By Y. Wong

The quality and quantity of secondary deposits, which include tailings streams and tailings dams, are increasing around the globe. The tailings are already mined, available and liberated to such an extent that the recovery of a valuable product is highly economical in terms of CAPEX & OPEX. The most widely used process for the recovery of these valuable ultra-fine haematite iron particles is the Wet High Intensity Magnetic Separation technique, originally developed by Dr. Jones over 55 years ago. Many of the original machines are still working today. The aim of this paper is to demonstrate the capabilities in terms of grade and yield of using sophisticated magnetic separation modules. All results and figures are obtained from test works, design- and engineering works. Two types of tailings have been identified for processing. Firstly, tailings that have already been deposited in a Tailings Storage Facility, and secondly, live tailings streams from an existing wet iron ore beneficiation plant. In both cases, the technical and practical results are shown along with relevant flow sheets and plant layouts. Finally, this paper highlights the total predicted power- and water consumptions, capital requirements and projected operating expenses. The results show that the operating costs are significantly lower than the mining and processing operations which are required for an equivalent amount of iron ore. The recovery % of iron depends on various factors but is within the 30–50% range, at an equivalent grade to the mainstream product. Another significant benefit is that the magnetic separation process is water positive, meaning that water is released rather than added in the process. The processing of secondary deposits will therefore result in an overall reduction in operating costs, an increase in product yield from a plant, extend the mine life and offer environmental benefits by reducing the tailings footprint and water usage.

Jan 1, 2016

By R. T. Seaman

There are several hydrometallurgical alternative processing options under development for high enargite and arsenic containing copper concentrates ranging from biological, atmospheric, medium temperature oxidation to total oxidative leaching. The most developed of these options is the CESL process boasting pilot campaigns totaling more than 8760 hours of fully integrated continuous operation, as well as, over two thousand batch scale oxidation tests performed on dozens of concentrates for flowsheet development. This paper reports the observed deportment of arsenic under varying arsenic, iron and acid oxidation conditions; it also describes the impact of iron to arsenic ratios and residue recycle on overall arsenic behavior and its stability in residue. INTRODUCTION The CESL Hydrometallurgical Process (CESL) was originally developed to compete with smelting of clean chalcopyrite concentrates. High Treatment Charges and Refining Charges (TC/RCs) combined with premiums on London Metal Exchange (LME) grade copper from onsite refining made treatment of copper concentrates using CESL a viable option at the time. As world demand for copper increased and a subsidized Chinese refining market developed, smelting contracts became more favourable for the miner and focus was placed on modifying the CESL Hydrometallurgical Process to handle concentrates with elevated deleterious elements. Dozens of pilot campaigns processing concentrates containing elevated concentrations of uranium, fluoride, mercury and nickel all led to further developments of the CESL Hydrometallurgical Process. In 2016 a United States patent was granted for a novel modification of the CESL Hydrometallurgical Process for recovery of copper from arsenic-bearing and/or antimony-bearing copper sulphide concentrates, Henry Salomon de Friedberg (2016). To date, over 2000 bench scale tests along with five fully integrated closed loop pilot campaigns, totaling over a year of online operation time, have been conducted processing arsenic bearing copper concentrates. This paper summarizes the observed behavior of arsenic under varying autoclave and process conditions.

Jan 1, 2019

By Douglas G. Jay

"Transfer points on belt conveyors have long been a source of problems for both designers and users. Conveyors are generally given a low priority in new equipment layout, thus designers are often forced to compromise due to space limitations. Consequently, for this reason as well as for reasons of initial economics, many conveyors are supplied with less than adequate transfer points.Although not intended as a cure-all, a number of existing installations have been modified with the result that spillage has been reduced to a minimum and belt life has been extended. The most striking modification consisted of replacing conventional rigid frame idlers with five-roll catenary idlers.Although catenary idlers can be traced back to the early 1900s in North America, with a patent having been issued in Washington, D.C. as early as May 29, 1907, the practical application of this concept has only recently reached North America. Major installations include applications at St. Lawrence Cement in Oakville and Iron Ore Company of Canada in Sept-Iles, as well as belt conveyors at Stelco's Nanticoke plant and yard conveyors at Syncrude in Alberta. These installations were part of major capital expenditures for new facilities and included complete conveyor systems.However, this article will discuss the use of catenary idlers on existing rigid frame conveyors for the purpose of absorbing the energy of falling lumps, protecting conveyor belts and reducing spillage. We will deal specifically with an installation at Inco Metals Company in Sudbury, Ontario, where approximately 40 five-roll catenary idlers were installed on a 42-in.-wide belt conveyor handling ore located under the railroad car dumper at the Clarabelle Mill. Before-and-after photographs clearly show the tremendous improvement in the cleanliness of the location, and the savings in maintenance costs and extended belt life have prompted Inco to consider modifying other conveyors."

Jan 1, 1982

By Robert B. Parsons

"The pendulum in Ottawa has swung dramatically from fiscal policy to monetary policy over the last several years. International trends indicate that the pendulum has to start its swing the other way, if Canada's mining industry is to maintain its preeminent position in the global mining arena. This article, which is based on a paper presented by the author at the 37th Annual Meeting of the Newfoundland Branch of CIM, identifies these trends and how they could interact with Canadian policy.IntroductionThe title of this paper is not a very imaginative or catchy one, but it states the topic quite succinctly, if not tersely. This paper looks into a crystal ball to see what might be in store for mine financing over the balance of the current decade.In the event that the reader feels some trepidation about the prospect that such a paper could seek to be the definitive work on the subject, it should be made clear at the outset that this is not the case. The author is, after all, not an economist, a scholar, a financial analyst, or a soothsayer, but is rather a simple accountant who has been closely involved with the mining industry, and the financing thereof, for some twenty years.The paper recognizes that, while a mine may be born when production begins, the mine is conceived when exploration starts. As this act of conception is obviously an essential part of mining, the financing of exploration is also covered in this paper. To attain a focus, this paper approaches the topic of mine financing in the nineties as follows: first, the major emerging forces in the industry are identified: and, second, the implications of each of these forces on financing are considered."

Jan 1, 1991