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By I. A. Cameron, F. Ham, R. Sriram

"Planned increases in electric furnace productivity and higher matte temperatures needed for the Sudbury Smelter's S02 Abatement Plan, require an improved matte tap hole. Since startup in 1978, the matte tap holes have been incrementally improved by the addition of copper cooling blocks around the refractory tap blocks. These improvements provided a tap block life of about 100 taps per campaign.In July 1993, a prototype matte taphole was installed in Number 2 Electric Furnace to develop the technology to increase tap hole service life. The design was based on a heat transfer model of the tapping process to determine candidate refractory materials and cooler arrangements. The prototype tap hole features increased copper cooling, high conductivity refractories and extensive instrumentation. Eight trial campaigns are reviewed outlining the performance of silicon carbide and graphite refractories and typical heat loads during tapping.IntroductionFalconbridge Limited operates two 36 MYA, 6 electrode submerged arc electric furnaces in Falconbridge, Ontario. The furnaces, commissioned in 1978, smelt a partially roasted nickel-copper calcine, to produce matte for converting and slag for discard. Additional details of the smelter are available in the literature(1-4).Each furnace was equipped with two matte tap holes located in the furnace end wall. Early in the campaign, matte tap holes were identified as a weak area in the furnace which could be improved. From 1981 to 1987, incremental improvements were made to the design by the addition of water cooled copper blocks. In 1993, a prototype matte tap hole was designed and installed in Number 2 electric furnace to develop the technology to increase tap hole service life. Improved service life is required to meet planned increases in electric fWl1ace productivity and the higher matte temperature needed for the smelter's S02 Abatement Plan.This paper reviews matte tap hole development since 1978; outlines the prototype matte tap hole design, refractory selection and installation; and details the performance of the prototype tap hole during the first eight campaigns."

Jan 1, 1995

By Roger Moss

OUTLINE Area selection Mineralization/Alteration Styles Island Copper Mineralization Geophysics Geochemistry Coppercorp Setting Mineralization Geophysics Geochemistry Formation Common Characteristics Conclusions

Apr 1, 2005

By P. M. Shibley

"IntroductionMine drainage, surface. drainage and process liquors are the principal mine and mill effluents. The quantity and quality of these flows varies according to mineralogy, type and scale of mining, the process, tailing disposal, local ground conditions and climate.Typical contaminants remaining after solids sedimentation are colloidal or semi-colloidal particles, acids, alkalis, metals in solution, cyanides and thiosalts. Environmental regulations and guidelines have been issued in detail by the appropriate government agencies and will not be reviewed here. Revisions and additions are being made as our comprehension and abilities increase. Some contaminants of consequence have not been specifically regulated as practical treatment technology has not been identified. Thiosalts fall into that category as do the derivatives of the first stage of cyanide oxidation - cyanates.Most mining activities have present or foreseeable water treatment requirements. Because process economics can be adversely skewed by the environmental factor, the acknowledged objective of every operation must be to identify and anticipate those requirements.The evaluation and selection of water treatment techniques for mine-mill applications is complicated by the fact that most mine-mill effluents are high volume, dilute and chemically complex systems. Treatment processes applicable to most contaminants are: chemical or biological oxidation; neutralization and/or precipitation; liquid/solids separation. Other processes such as ion exchange, electro-deposition, foam fractionation, freeze crystallization and reverse osmosis offer the possibility of selective removal or concentration of contaminents. The latter tediniques, representing a slightly higher level of technology, are less suited to the large, low value flows usually encountered in the mine environment."

Jan 1, 1989

By R. Thierbach, W. Kahnt, Oberthür. T., D. Eisenburger, V. Gundelach

ABSTRACT: The ground penetrating radar (GPR) method was used in a platinum mine in Zimbabwe by members of the Federal Institute for Geosciences and Mineral Resources (BGR). The measurements were carried out in boreholes and drifts. Electromagnetic re?ections from a fault that consistently trends parallel to the mineralization zone permitted the mapping of the economically minable parts of the deposit. An introduction is given to the geology of the studied area and the application of the GPR method. The electrical parametres of the rocks are measured in situ, the GPR measurements are displayed with radargrams, and the visible structures are explained in illustrations.

Jan 1, 2010

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 '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 Aysan Molaei, Kristian E. Waters

"Solvent extraction is the one of the most common techniques for recovering metal ions from aqueous systems. However, it is not efficient in the extraction of low concentration metal ions from aqueous solutions. Predispersed solvent extraction (PDSE) is an alternative method for solvent extraction which implies colloidal liquid aphrons as extracting agents in order to reach higher interfacial area and lower reagent consumption. This work investigated important parameters in PDSE of nickel ions from dilute aqueous solutions by fractional factorial design of experiments. Four experimental parameters, the initial extractant concentration, initial surfactant concentration, equilibrium pH and phase volume ratio (organic to aqueous ratio) were investigated. The important parameters were determined as well as important interactions between these parameters. It was found that extractant concentration, phase volume ratio, and equilibrium pH are the most significant experimental parameters. However, the interaction between surfactant concentration and other parameters was determined as significant interactions.INTRODUCTIONNickel is one of the key components found in cars, mobile phones, rechargeable batteries, kitchen appliances, and steel industry (Anyadike, 2002). It is one of the most important metals produced by Canada which is in the five top nickel producers in the world. Despite a 24% decrease in the nickel prices from 2011 to 2014 the nickel global mine production increased by 36% between these years (U.S. Geological Survey, 2015; Nickel - Statista Dossier, 2015), which shows the increasing demand for nickel. This high demand leads producers to consider the production of nickel from low grade ores and other secondary sources such as process wastewaters. The removal of nickel ions from process wastewater is also important due to environmental considerations. Nickel is known to be a human carcinogen and it may cause serious lung and kidney problems, pulmonary fibrosis, gastrointestinal distress, and skin dermatitis if it exceeds the critical level (Borba et al., 2006; Fu & Wang, 2011)."

Jan 1, 2016

By Robert B. Parsons

"This month, Tax Notes focuses on two features which can potentially ""dress up"" a new issue of common shares to make the shares more attractive to investors. Attaching warrants to a share issue is a relatively common practice, and recent years have seen an imaginative variety of different kinds of warrants, some of which can be subject to somewhat different tax treatment . A less common financing strategy which certainly deserves some consideration involves the possibility of utilizing ""Share Purchase Tax Credits "" in conjunction with a new share issue.IntroductionPrevious subjects covered in Tax Notes have dealt with flow-through shares and other tax angles which can make equity issues more appealing to potential investor s. Two other techniques which can add zest to a new stock issue involve the utilization of warrants and ""share purchase tax credits"" (or SPTCs). This article takes a brief look at the better known subject of warrants and the lesser known matter of SPTCs.Of course, this paper presents only a relatively general summary of the income tax implications of warrants and SPTCs, and is not intended to be a definitive commentary on all of the detailed and complex tax issues that might be relevant in the circumstances."

Jan 1, 1985

By N. Fukatsu

The recent development of galvanic cell-type hydrogen sensor for molten copper was outlined. The principle of the sensing mechanism, the fundamental structure of the sensor, and its performance as a process control device are discussed based on experimental work undertaken by the authors. Besides sensors based on usual perovskite-type proton conducting oxide, those using magnesium-doped alpha alumina, which was recently known as a proton conductor, were investigated and the results at the laboratory scale are reported. Considering the excellent sensitivity at high temperature and the stability to the disturbance from the attendant oxygen activity, magnesium-doped alpha alumina was regarded to be a superior material for the sensors used for such purposes.

Jan 1, 2007

By Thomas J. Ferree

"There has been a major evolution of mineral processing technology in the past decade. The evolution has been driven by recognition of broad environmental changes which have impacted various areas of the world. Numerous government regulations have required many mining and mineral processing organizations to introduce changes to reduce the undesirable effects on the environment; many mining companies have voluntarily introduced new technologies and practices which surpass the limits imposed by the regulations. Surprisingly, some of the 'new' technologies are modifications of concepts developed decades earlier. Gravity separation technology is in this category.Mineral Deposits Limited, an Australian company, has been a world leader in the development of mining concepts, reclamation practices and equipment technology that is environmentally suited to today's requirements. This paper relates to equipment used for gravity concentration and electrostatic separation systems, including Reichert cones, spirals, and electrostatic separators. The basic devices and technologies were developed more than forty-five years ago, but use of the systems was quite limited until environmental and conservation practices were recognized and introduced. Spiral concentrators, for example, were patented in the mid-l940s by I.B. Humphreys in Denver , Colorado. The two types of spirals marketed (the Model 24A for minerals and the Model 24C for coal) remained essentially unchanged until expiration of the patents. During this early period most spirals were used in iron-ore wash plants on the Mesabi Range to recover fine iron which previously had been discarded. About the same time sand mining plants in Florida incorporated spirals to recover titanium minerals and zircon from lowgrade beach sands. The Labrador Trough opened new opportunities for spirals when hard-rock iron-ore deposits were developed; approximately 10 000 Model 24A Humphreys spirals were installed between 1958 and 1966. About 5000 spirals of this model are still operating in the same capacity, in spite of the fact that extensive improvements have since been made in gravity separation technology."

Jan 1, 1993

By I. H. Warren

"An analysis of form-coking processes is presented in terms-of their fundamental mode of operation and their relationship to other coking processes. Their possible future role in cokemaking is assessed. IntroductionAny consideration of prospects and possibilities for form coking must commence with the iron and steel industries-their likely future growth pattern on a world and regional basis and the potential direction of future developments in iron and steelmaking technology.From the numerous estimates which have been made of the future consumption of steel, it would appear that a growth rate of 3lllo between now and the year 2000 is likely. Radical changes in steel making technology are unlikely to be commercially adopted on any significant scale during the next twenty years . However, widespread commercialization inter alia of continuous casting and direct reduction, growth of electric furnace steelmaking and a decrease in coke rates will all contribute to a growth rate for metallurgical coke that certainly will be less than that of steel."

Jan 1, 1980

By D. R. Spink, G. L. Rempel, C. O. Gomez Bueno

"A morphological and chemical study of the Great Canadian Oil Sands Ltd. (GCOS) fly ash has been carried out. Extensive scanning electron microscopy, as well as light microscopy, showed that the GCOS fly ash consists of two fractions, one composed of unburnt or partially burnt irregular-shaped carbon particles and an ash fraction composed of transparent and opaque, often coloured, glassy spherical particles-some of them cenospheres (hollow spheres) and the others plerospheres (hollow spheres packed with smaller spheres). Microcrystals (0.1 to 0.3 um long) growing on the inner and outer surfaces of some of the spheres were also noted and found to contain more Fe, Ti, Ni and V than the spheres.The carbon-free GCOS fly ash particle size follows a lognormal distribution, with a geometric median particle size (by count) of3.8um and a geometric standard deviation of 1.84. IntroductionCanada's current energy situation strongly suggests that oil from the Alberta tar sands deposits will probably be recovered more extensively in the future. Today's commercially proven technology to recover oil from the Athabasca tar sands, as practised by Great Canadian Oil Sands Ltd. (GCOS), involves two major operations, namely: separation of the bitumen from the sand and upgrading of the bitumen to refinery oil; the production of significant amounts of petroleum coke and sulphur during the bitumen upgrading process. The bulk of the petroleum coke is burnt in boilers to fulfill the energy requirements of the entire operation. The boiler ash, which contains appreciable amounts of metals, such as vanadium, nickel, titanium, iron, aluminum and other elements, is collected in the boiler hoppers and cyclones of the petroleum coke-fired steam generation plants. Thus, as well as representing a petroleum resource, the tar sands represent a resource for vanadium and possibly other metals providing that metal recovery processes can be developed."

Jan 1, 1980

By Leonard A. Wolff

"The 1980sfor the mining industry can be characterized as the survival of the fittest. High interest rates, low commodity prices, foreign subsidized competition and decreasing ore grades have contributed to a streamlining of the domestic mining industry in the United States, leading to the shutdown of operations or large cutback of work forces. The purpose of this paper is to look at the impact of a layoff on the employees of what was once a major uranium producer in south central Wyoming, twenty months after the final layoff and mine shutdown. INTRODUCTIONDecember 19, 1985, was the date of the final of three successive layoffs over a two-month period, leading to the complete shutdown of Petrotomics Company, a subsidiary of Getty Minerals Company. The final shutdown was due to a combination of depressed U3O8 prices and the takeover of Getty Oil Company by Texaco in January 1984.The layoffs affected 104 employees and included mine personnel, mill personnel and staff. Both hourly and salary workers were involved. The operation was considered non-union, however, a few mill hourly employees were unionized. At the completion of the layoffs. only a handful of employees remained for administrative and miscellaneous functions.For Getty employees, the terms of the merger agreement provided a generous level of separation benefits. The terms that were insisted upon by Mr. Petersen, Chairman of the Board for Getty Oil, stipulated that employees receive one month of severance pay, for each full calendar year of employment up to a maximum of two year's pay. This was the forerunner of what is now commonly known as the ""tin parachute”. All but the union employees of Petrotomics received these separation benefits. Union employees were covered by their separate, less generous, contract.Much of the literature that has been published in recent months has centred around the effects of layoffs on remaining employees, or the psychological effects on the severed employee. This study will emphasize the economic impact and ramifications due to a layoff, using the Petrotomics employees as a case example."

Jan 1, 1989

By C. J. Kerr

"A recent information sheet from the Mining Health and Safety Branch of the Ontario Ministry of Labour was sent to all Ministry inspectors and engineers. The subject title was' 'Two Brakes on a Hoist Carrying Persons"" and it quotes mining regulation 699, sub-section 206(i):No hoist shall be used for the transporting of persons unless it has a braking system consisting of at least two sets of mechanical brakes to stop and hold the drum for the shaft conveyance transporting the persons.The intent of the regulation is that each of these brakes is to be set so that, individually, they can safely stop the drum carrying persons and also hold the drum without movement with the maximum manload.This can be achieved in the following ways: Single Drum Hoist-one brake on each side of the drum, one brake on the drum, one brake on the pinion shaft, where disc brakes are used two separate disc brake assemblies on the disc. Double Drum Hoist, brakes on companion drum can serve as backup brake only pinion brake with one drum unclutched.Friction Hoist, one brake on each side of drum As new hoists can be manufactured easily with a two-brake system, attention will be focused on retrofitting pinion brakes to older hoists.A brake mounted on a pinion shaft is designed purely as an emergency brake in the event of main brake failure , controls malfunction, and power loss."

Jan 1, 1989

By Henry Brehaut

"It is difficult to know how much environmental information is absorbed by those in a position to put it to use. The following information may seem like ""old stuff"" to those whose companies are taking steps to improve their environmental performance. This paper is directed in particular to those people who are interested in determining what further changes are required to make improvements as concerned environment citizens.IntroductionUntil recently, the author was comfortable with the fact that none of the operations for which he was responsible had any environmental charges against them. It was not until one of his operations was charged with non-compliance that the author discovered due diligence as a way to avoid a second charge, and when an unfortunate spill occurred at another operation, the meaning of risk prevention was learned. Knowledge was gained step by step to the point where finally environmental information is being heeded, rather than waiting to learn from sad experience. With the appreciation of what it takes to do a good environmental job, comes an understanding of the challenge that lies ahead, and the fact that there is a lot to learn.At a recent environmental gathering, comments from the participants varied considerably. Some just didn't understand why government was being so unreasonable, while at the other end of the spectrum one individual whose company was well along the path to becoming a good environmental citizen remarked that it was all very basic. What was immediately understandable to one went right over the heads of others, indicating the different stages that have been attained in the acceptance of environmental responsibilities."

Jan 1, 1991

By M. M. Hajdasinski

"Any study in the field of theoretical investment analysis, or practical project evaluation, must be based on the assumption of one of the commonly applied models of time and value representation, and the corresponding interest convention. The lack of clear assumptions in this regard may easily confuse both the author of the study and the reader, and sometimes even lead to inaccurate results.In the first part of this paper formal definitions of the continuous and discrete models of time and value representation are introduced; in the second part, the importance of transparent assumptions is shown using a concrete example of inflation calculation in project evaluation.IntroductionIn his recent paper, L.D. Smith(10) discusses an important aspect of mine investment analysis: inflation in project evaluation. His interesting presentation of current practices of handling inflation by Canadian and international mining companies in their feasibility studies ends, in the conclusions, with a call for clear assumptions made when evaluating mining projects.With this call, an important issue has been addressed. The lack of clearly stated assumptions, or their incompleteness, are relatively frequent with regard to the interest convention or the model of time and value representation assumed when evaluating mining projects. It is, for example, fairly common that the quantitative evaluation of a project is performed according to the discrete model of time and value representation and the discrete interest convention, and the graphical presentation, supporting this evaluation, reflects the continuous model.Sometimes such an ambivalency means nothing more than just a formal inconsistency; there are cases , however, that may well lead to a serious confusion and /or to inaccurate results . Before this can be demonstrated on a specific example, a concise description of the models of time and value representation used in the evaluation of industrial projects seems to be in order. Although these models (especially the discrete one) have been in common use in the research and practice of financial analysis for considerable period of time, they have been applied rather intuitively, and their forma] definitions are difficult to find even in the standard textbooks on Engineering Economy."

Jan 1, 1990

By Derek Harvey

"The paper briefly describes the development of the Eickhoff ESA60 roadcutter which is based on the old and well used principles of the shearer loader. It is intended to show that the machine offers a viable alternative to the normal methods used for driving roadways and also for coal production . References are made to installations currently operating in Europe with applications ranging from roadway drivage to pillar recovery. The paper also looks at possible applications in Canada.IntroductionThis paper is an attempt to show how the principles used in mechanical cutting, conveying and roof support are being applied to a development system capable of catering to a variety of situations and conditions. It is also intended to illustrate how the same system can be used as a total mining system for the mining of many minerals.In order to give some sort of time perspective to the age of the principles, reference can be made to an article in Coal Mining & Processing which states:- During World War II the Germans developed the "" panzer"" or armoured face conveyor.- After the war the English developed power cutters or trepanners that were mounted on the face conveyor, this then developed into the shearer.- The first shearer was produced by the Anderson Company in England in 1950 and shortly after that the Eickhoff Company started manufacturing shearers in German y.- The first hydraulic roof support was produced in 1954 by Gullick.This is a potted history of the three major components of the new system, i.e.:- Mechanical cutting element based on the shearer.- Transport element based on the panzer.- Optional roof support based on the hydraulic face supports.It can therefore be said that since the "" youngest"" of the elements was produced in 1954 the principles of the system in respect of the rapid change in mining equipment are in fact old.Of the three major components the most important is the cutting element since the major benefits of the system are to be obtained from this."

Jan 1, 1985

By M. W. Mikhail, R. J. Mikula

"Funding has been made available through the National Energy Program to build a mobile fine coal treatment plant. The plant is intended f or field application and also to upgrade the existing pilot plant facilities.Western Canadian coals with high proportions of fines (due 10 their friability) cause high losses of fine coal to the reject and in turn reduce the over-all recovery of saleable coal. Eastern Canadian coals with high amounts of sulphur of ten require crushing to fin e sizes to liberate pyrite and therefore need effective and efficient separation of these fine sulphur particles. The difficulties involved in solving these problems are two-fold. One is the reluctance to experiment in an operating wash plant and the other is that laboratory scale testing often cannot be extrapolated to the plant environment. The mobile fine cleaning plant with its ability to operate at existing coal preparation plants across Canada and with its flexibility in implementing flowsheet option s and close monitoring of fine coal circuit variables, is ideally suited to solve these fine coal cleaning problems. The mobile plant objectives are to design and optimize flowsheets, evaluate and improve fine cleaning circuit operations and 10 lest new process monitoring and control equipment.The schedule for construction and the required resources will be outlined along with flowsheet options and the general R&D philosophy of the mobile plant.IntroductionIn relation to coal preparation technology, Canadian coal s can be grouped as Eastern coal, Rocky Mountain metallurgical coal and Foothills high volatile bituminous coal. The eastern coals have high sulphur contents and in some cases require crushing or even grinding to liberate the fine pyrite . Rocky Mountain metallurgical coals often occur in highly sheared seams which have been subjected to rapid coalification. The high friability of these coals means that degradation during mining, handling and processing is extensive and results in large amounts of fine s ranging between 20 and 60% by mass of the wash plant feed. The widely varying geo logical structure and exposure to the elements results in partially oxidized coals which perform inconsistently in the traditional method of fine cleaning by flotation . Foothills high volatile bituminous coals for thermal use are frequently interbedded with soft shales and bentonitic clays. These clays disintegrate during washing and swell, producing large volumes of tailings. The presence of clays in plant circuits, particularly fine circuits, tends to increase the viscosity and may cause deterioration of the fines density separation and increase magnetite losses. In view of the fact that fine coal cleaning is the most difficult aspect of coal preparation , a research program is being established to study the factors involved and to offer some solutions.A recent performance evaluation of Canadian washeries showed that yield losses in the minus 2 mm coal circuits were approximately ten times those occurring in the coarse coal circuits(1). Because 2 mm x 0 coal represents 30 to 70 per cent of the raw coal, these losses can be considerable . The operating and capital costs of beneficiating minus 6 mm coal are about four to five times higher than for plus 6 mm coal. In the case o f minus 2 mm coal the costs are even higher. The economic importance of the fine coal cleaning cannot be over emphasized and as a result, the CANMET R&D program is geared for fine coal beneficiation."

Jan 1, 1984

By William E. Stanley

The paper examines the problems that arise in undertaking socio-economic impact studies to meet the requirements of environmental-impact legislation governing new mine development or expansion. An approach to undertaking socioeconomic impact studies is outlined, responses to specific problems are discussed and ways in which the mining company can use these studies to meet its general objectives are explored. The paper concludes by examining how a socio-economic study, as required by legislation, can be used to assist the mining company in achieving some general objectives it will have in developing a mine.

Jan 1, 1979

By Errol Ladner

The application of large-diameter bore holes in underground operations at Heath Steele was first tried in February, 1975. Since that time, 90,000 feet of 6-l/2-inch holes have been drilled, primarily in open blasthole stoping, for a total of 1.4 million tons, 37% of underground production. This paper deals with a review of drilling with conventional percussion longhole drills, a practice which is still utilized at Heath Steele, and the changeover to accommodate the use of larger blastholes in underground operations. The discussion will include layouts for 2-inch-diameter blasthole stope blocks, 6-inch-diameter stope blocks, trials for I. T.H. (in-the-hole) stope rooms, and drill pat/ems, drilling and performance. The complexity involved in the development, drilling and blasting of 2-inch blastholes is overcome by the over-all simplicity of drilling and blasting in I. T.H. stopes. This has made the practice of open blasthole stoping more economical and efficient. The future indicates an increase in the company's I. T.H. program. Investigations are being undertaken regarding longer holes to decrease development costs. A VCR stope is also being developed for trial.

Jan 1, 1979

By D. Crone, T. Watts

"The Lindsley project was a program of deep drilling to test the contact down-dip from two nickel-copper deposits, one uneconomical and the other mined out. The role of Borehole Pulse EM(PEM) was to detect the higher grade, more massive sulphide zones if they were missed by a drillhole, and to help determine geometry if the zones were intersected. Two problems appeared as the PEM survey progressed: (1) conductivity-thickness as measured by the PEM did not always relate to economic sulphides as determined by the market; (2) a pattern of unusual PEM anomalies was obtained that indicated something odd and big, but the cause was unknown. A large fold structure subsequently was indicated by a program of deepening previous holes, the third of which intersected high-grade mineralization below 1280 m. Falconbridge is in the process of shaft sinking and underground exploration.IntroductionThe Falconbridge Lindsley property is on the south rim of the Sudbury basin, 8 Ian north of downtown Sudbury. The original property was acquired by a prospector named James Stobie, who, in early August 1885, staked a showing that later became the Mount Nickel mine (Fig. I). On August 10 Stobie staked another property that would become the Little Stobie mine, and at the end of the same month he staked the main Stobie orebody.In 1888, the ground immediately west of the MOlU1t Nickel find was staked. This ground contained the Blezard deposit (Fig. 1) which was put into production in 1889 and was eventually acquired by Inco. Down-dip from the Blezard workings, on Falconbridge ground, is located the upper Lindsley No. 1 deposit which was drilled off by Falconbridge in the 1940s to 1950s. A decision to go underground on the Lindsley No.1 mineralization was made in 1969, but the project was cancelled in 1971 because of declining nickel prices. The shaft was stopped at 95 m, and the headframe and hoist were sold. Further surface exploration drilling in the 1970s discovered the deeper Lindsley No. 2 zone, but as it had grades similar to those of the No. 1 zone, it too was considered uneconomic."

Jan 1, 1992