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By J. C. Roy, S. Couture, C. Barbeau

The chemical composition of the asbestos tailings from different mines in the Eastern Townships of Quebec are fairly uniform in composition. The serpentine minerals antigorite and chrysotile form about 85 to 90 per cent of the total. Iron oxides add another 7 to 10 per cent; magnetite represents about 70 per cent of the oxides. Chromite is present in amounts of about 0.5 per cent. The average contents of elemental magnesium, iron and nickel are 23, 6 and 0.25 per cent respectively.

Jan 1, 1972

By Robert B. Parsons

"A study recently completed by the Prospectors and Developers Association, assisted by the author and computerized mine models he developed, presents a strong case that present tax rules severely handicap the junior exploration company relative to the established producer. This month, Tax Notes briefly summarizes the highlights of the study and some of the Association's ideas which came out of the study.IntroductionIn the case of any industry, a particular project or investment will generally generate a more attractive after-tax rate of return to a tax paying entity than to a non-tax paying entity: the ability to shelter current taxable income with tax deductions related to the project or investment can present a definite advantage as compared to shielding taxable income in the future with the same deductions. But, this advantage is probably seen nowhere more clearly than in the mining industry where the tax rules allow for substantial up-front write-off's. Studies show that the junior mining company which is earning no taxable income currently can be seriously disadvantaged, compared to the mining company which is currently generating taxable profit and paying taxes. This is particularly disturbing when one considers the importance of the junior segment of the mining industry. One might well ask where the equity is, in a tax system which causes the junior company to look at a deposit and see rock in the ground, when at the same time the deposit represents a viable mine to an operating company. This inequity and the importance of the junior mining company have been recognized to some extent in the income tax legislation. In recent years, the expansion of the rules for deducting certain earned depletion allowances against any source of income, and changes to improve the flow-through share rules, have gone part way in helping to put the junior on a more equal footing with the operating company. But it is questionable whether or not these helpful changes to the tax rules have done enough to alleviate the apparent inequities in the income tax legislation."

Jan 1, 1985

By M. A. Sobhi, L. Li

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

Jan 1, 2015

By 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 M. Y. Williams

Introduction During the economic investigation of Pacific Great Eastern Railway subsidy lands, the P.G.E. Survey of Resources made a geological and mineral survey of a large part of the valley of the Peace river as included in the Province of British Columbia. The immediate valley of the Peace river was surveyed from the mountains to the Alberta boundary; the valley of the Pine river was surveyed throughout; and the Dominion block, 70 miles square and lying astride the Peace river, westward from the Alberta boundary, was very carefully surveyed. The writer was in general charge of the field work, and spent half the field season of 1929 and the field season of 1930 in the region . J. B. Bocock, however, did the major part of the work, spending two seasons, 1929 and 1930, in the area. General Conclusions The rock formations within the area discussed are all sedimentary and range in age from pre-Cambrian to recent. As might be expected, the minerals are in the main non-metallic, coal being by far the most important. Favourable conditions exist for natural gas occurrence, and suitable structures for petroleum concentration occur, although the high carbon ratio of the coals sheds considerable doubt upon the actual occurrence of oil in the area. Materials of minor interest are ochre, calcareous tufa, marl, limonite, gravel, and building stone.

Jan 1, 1934

By A. S. MacNeil

In the operation of any colliery, a factor of prime importance is power, of which there are three sources available--man, horse, and mechanical. It is obvious that man-power is by far the most expensive, .and that animal-power, also, is more costly than mechanical. In recognition of this fact, mine owners must, for economical ?reasons, reduce the use of man-and horse-power to the minimum by the increased use of machinery. In other words, they must aim at as complete mechanization as conditions will permit, taking advantage of existing physical factors that are favourable and making the necessary adjustments and modifications to meet the less favourable conditions. Intensive coal-mining, or the concentrated production of coal, has two distinct objectives: First, the maximum production from a limited area, in a given time, thereby reducing the pit-room to be maintained; and second, reduction in cost. To this end the coal should be mined, loaded and delivered to the surface by mechanical means wherever possible. To do this, however, requires the solution of many problems arising out of the varying conditions that obtain underground. The system of longwall mining lends itself to a more efficient scheme of mechanization than does pillar-and-room, as, in the former, the first step has already been taken by the removal of all the coal in one operation, and the opening-out of one face, the equivalent in mining area of fifteen or more rooms. Much has been clone of late towards mechanization in the longwall mines of the Sydney coal-field, and with gratifying results, but not without great difficulties and frequent disappointments. In 1923, an attempt was made with shaker conveyors. The introduction of conveying was a step to bridge the gap between the face, where the coal is produced, and the main transportation arteries leading to the slope or shaft. The receiving of the coal at the faces and its delivery to main loading points on main haulage-ways was the part allotted to the conveyors.

Jan 1, 1932

By Neda Zangeneh

Production efficiency from low permeability gas shales require techniques to optimize hydraulic fracture completions. One completion strategy involves the simultaneous or near simultaneous hydraulic fracturing of multiple horizontal wells to maximize the fracture network area and stimulated reservoir volume. However, changes to the in-situ stress field caused by an earlier hydrofrac on subsequent hydraulic fractures are not accounted for in traditional hydrofrac design calculations. Presented here are the results from a set of transient, coupled hydro-mechanical simulations of a rock mass containing two wellbores using the discontinuum-based distinct-element method. The results demonstrate the influence of stress-shadows generated by a hydraulic fracture on the development of subsequent hydrofracs from an adjacent well. It is shown here that these interactions have the potential to change the size and effectiveness of the hydraulic fracture stimulation by changing the extent of the hydraulic fracture around the secondary well.

Jun 1, 2012

By F. Osmond, R. Kelly

"Malcolm Knowles, the famous adult educator once wrote: ""What a challenge we in human resources development face if we are to avoid the obsolescence of our workforce. I can foresee this challenge requiring that we reconceptualize (...) and redefine the role of HRD, away from that of managing the logistics of conducting training activities to that of managing a system of learning resources"".The context in which this was written surrounds the subject of adult education and the need for business and industry to change its approach to the treatment of adults as learners. In explaining what 'managing a system of learning resources' means, Knowles refers to line supervisors and managers as the most ubiquitous resources for day-in and day-out employee development. In many organizations training has been largely a staff rather than line responsibility. Even where trainers reported to line management, it was still seen as a staff function performed by a few specialists.This change referred to by Knowles places a much heavier responsibility on line supervisors and managers for the development of their personnel than has traditionally been the case. Managing that change - handing over the responsibility to the line organization - is the supreme challenge for the HRD function.Just why is this change necessary? Because too often, the learner does not effectively use on the job what he or she learned in the classroom. In fact, learners often discard new methods and revert to the older ways. The reason training does not stick is that the systems for training and work management are most often separate entities and while one may support the other, they need to be a single integrated system in order to ensure the transfer to the job effectiveness of training and some real value for the training dollars.Because much training can be wasted, steps have to be taken to ensure that it fulfills its intended purpose. The effective and continuing application of knowledge and skills that learners acquire can only be realized when line supervisors and managers are at the centre of the training system.This paper describes how such a systemis being developed at the Iron Ore Company of Canada (IOC) as a functional training program is introduced. The following text provides background information on the IOC - who they are and where they are located, a definition of functional training, an evaluation of the suitability of this approach for adults in industry, a description of how the program is being implemented at IOC and some observations that have been made as this change is experienced."

Jan 1, 1995

By A. Dolatmoradi

Nanocrystalline structure formations produced by severe plastic deformation in Fe-0.15C with initial ferritic-pearlitic and IF steel with ferritic microstructures have been studied through microstructural observation and microhardness measurements. It was found that the nanocrystalline region first forms near the surface of samples due to localized severe deformation. It was also observed that the nanocrystallization rate of Fe-0.15C and IF steels and the deformed layer thickness in these two materials are different with similar milling conditions. The crystallite size and structural evolution of the samples during milling was studied by employing XRD and SEM.

Jan 1, 2010

By George J. Thompson

This pa per deals with the internal characteristics of steel and its response under cold northern temperatures. General maintenance procedures and specific repair techniques are covered.

Jan 1, 1973

By J. H. McKibbon

This paper outlines the basic steps in the sizing of electrostatic precipitators according to the Deutsch equation. Design parameters that do not appear in the equation are also described.

Jan 1, 1971

By J. R. Bradfield

THOSE familiar with the development of the Horne mine can readily appreciate that more and more accommodation bas been required for underground labour as the mine has grown. A permanent fire-proof change house, 30ft. by 75 ft., was built in 1927 to accommodate 194 men. This was extended ro 30 ft. by 92 ft. in 1928 to accommodate 296 men, and to 30ft. by 110 ft. in 1930 to accommodate 398 men. By 1933 this building was again overcrowded and tentative plans for a new change house were drawn up. However, it was realized that future operations would be centred around No. 4 shaft and a proposed new shaft, and the decision as to the location of the new change house had to be deferred until the area which seemed most suitable for the new shaft had been thoroughly explored underground. In the spring of 1934, the basic idea was accepted of drying the wet clothes in open mesh compartments or baskets located between rows of standard steel street-clothes lockers and built so that the covers or lids would serve as seats or benches.

Jan 1, 1935

By D. François-Bongareon

"In previous publications by the author, significant advances and generalizations of the theory of sampling of broken ores, prompted and confirmed by experimental results, have been presented. This paper shows how to implement these theoretical results in practice. The models to be used are reviewed, with a description of the various sampling parameters involved. Then the methodology for the experimental assessment of those parameters, including segregation factors, is described in simple and practical terms, along with the use of handy sampling protocol charts. Finally, the particularly important case of processing data from a sample-tree experiment is detailed, and examples of applications covering all situations and types of experiments are provided.IntroductionThe reliability of a sample of crushed material , i.e. the expected (average) deviation between its true grade and the true grade of the lot it comes from, mostly depends upon six factors:• the size (mass) of the sample (and to a minor extent, for small lots, the size of the lot);• the size of the rock particles (degree of comminution)• the nature of the mineralization at microscopic scale (i.e., within even the smallest particles);• the geological nature of the mineralization and mineral of interest;• the grade of the lot in the mineral of interest; and• in some cases, the state of segregation of the lot.In practice, one should first disregard segregation problems, and assess sample variability in the segregation-free case. Once the numerical parameters governing this variability have been assessed, then segregation factors can be assessed in turn. In the case of laboratory standard sample preparation procedures, segregation can usually be disregarded altogether."

Jan 1, 1993

By J. F. Wright

The cold, or Kississing, Lake area in northwestern Manitoba was the scene of considerable prospecting and mining activity last summer. At the Sherritt-Gordon property, four diamond drills were at work exploring a large deposit of copper and zinc ore, and underground work was in progress on this deposit from two shafts. Some preliminary diamond drilling was completed in five other deposits, and surface exploration work was in progress at a dozen or more additional localities where copper and zinc sulphides were known to be present. Many prospectors visited the area and spent some time in search for new deposits, but apparently few discoveries were made; consequently, last autumn some returned a little disappointed in the area as a prospecting field. Although many visited Cold Lake area last summer in the search for mineral deposits, it should be emphasized that this new prospecting field is a very large one, and that to date only a small proportion of the ground has been examined, except in a very general way. Within the past 18 months, a village of several dozen cabins, and with a population of l00 or more persons, has sprung up on the shore of Cold lake, just west of the Sherritt-Gordon mine. This at present is the business centre of the area, and two banks, a post office - named Kississing by the Postal authorities - a Mining Recorder's office, as well as several restaurants and stores carrying a fairly complete stock of groceries, dry-goods, and general prospecting equipment, are already established.

Jan 1, 1929

By Marcel Laflamme, N. R. Rillette

"In 1982, a study was initiated to investigate relationships between bonus and accidents in Quebec underground mines. In 1983, the study was expanded to include the impact of age and experience on accidents.The paper will describe the methodology followed in gathering information at ten mines from three mining camps in the Province of Quebec, and its transfer to data banks for subsequent treatment. Multifactorial analysis of nine variable files for the ten mines has shown: that age, experience and seniority are linked; that total working hours are tied with overtime; that bonus is linked to the main activity of the miner, and not to accidents. The most tangible factors affecting accidents seem to be the introductory training and subsequent retraining at regular intervals."

Jan 1, 1989

By A. G. Pentland

PROSPECTING is popularly supposed to be surrounded with an air of romance and adventure. The word 'prospecting' brings to mind high mountains, northern lakes, and aeroplanes. A note of urgency has been added to this by the war, particularly in the case of strategic, minerals. Prospecting for strategic minerals in a modern mine in full production, although it may Jack the romance of travel in little-known places, has the advantage of having all the necessary machinery at hand and ready to go into action at a moment's notice. HISTORY Tin was discovered in the Sullivan ore in 1925, when a white streak was noticed on a pilot table which was being used to check the amount of galena in the tailing. The mineral which made up this streak was identified as cassiterite. The amount of tin in the ore is so small that, while of scientific interest, it was considered to be of very little economic importance. Nevertheless, several attempts were made to learn something of the occurrence during times when other work was nor pressing. These studies were dropped when anything came up that seemed more important.

Jan 1, 1943

By Karen M. Moffitt

Developments in mining methods and rates have led to an increase in the frequency and size of waste dump failures that have not been adequately predicted or explained in terms of conventional slope stability analysis. Monitoring data and visual observations suggest a unique mode of failure responsible for large runout events. A numerical model has been developed to capture commonly observed patterns of deformation, and investigate the formation of the ensuing failure mechanism. The analyses have yielded a good correlation with observed field behaviour and have provided significant insight into the coincident stresses and deformations within the dump. Results indicate that while creep effects in the waste dump could have a significant effect on the magnitudes of displacement, the overall dump stability is governed by the strength of the foundation soils underlying the toe region. Consideration of both the stress and velocity fields leads to factors of safety for various dump heights and foundation slopes that are considerably less than predicted from limit equilibrium analysis. The results suggest that conventional limit equilibrium analysis techniques may not be adequate when assessing the stability and design of waste dumps on steeply sloping terrain.

May 1, 2001

By R. K. Kandasami

"Naturally occurring geomaterials such as sandstone, limestone and other soft rocks, residual soils are composed of a particulates held together through a cohesive matrix, usually composed of argillaceous or siliceous cementing agents. Geo-materials such as these have been reconstituted in the laboratory using ordinary Portland cement in lieu of the naturally occurring cohesive matrix, in addition to using sand particulates. This cohesive frictional granular ensemble is an ideal model material for understanding the mechanical behaviour of transitional geomaterials such as soft rocks. An important consequence of this cohesion that pervades the inter particulate system is the enhanced tensile strength when compared to a purely granular ensemble. The assessment of strength of these soft rocks and cemented sands is often understood in the framework of continuum mechanics, i.e. considering the cemented sand to be a continuum, and performing simple elemental tests such as uniaxial compression or tension tests. A simple model to describe the behaviour of these cemented sands has been to use elements such as springs, sliders, and dashpots in parallel to describe the existence of a cohesive and frictional component of strength (Jiang et al. 2007). In the framework of continuum mechanics, the mechanical response of these cemented sands have been modeled using traditional plasticity theory, for example utilizing variants of the traditional Mohr Coulomb model, Modified cam clay (Sun and Matsuoka 1999) etc. The typical sand models are amended to include the effects of cohesion, as proposed by Lagoia and Nova (1995).The mechanical response of cemented sands is understood to be transitional to the behaviour of a typical particulate assemblage and a quasi-brittle material. However, the effect of length scale in these material systems has not been investigated. This paper presents a series of uniaxial compression experiments conducted on weakly cemented sand specimens of various sizes. The effect of length scale in these weakly cemented sands is investigated through unconfined compression tests."

Jan 1, 2015

By P. S. Daly

"The purpose of this paper is to describe the types of instrumentation used at Sherritt Gordon's Ruttan Mine to monitor the"" effects of mining. The aim of the monitoring program is to establish parameters to achieve a maximum ore recovery with minimum dilut ion in a safe environment.The copper-zinc Ruttan Mine is in northwestern Manitoba, approximately 760 km from Winnipeg (Fig . I) . Production commenced in 1973 from the open pit at the rate of 10,000 tons per day. Pit bottom lies 58 metres above the first mine level. Underground development has overlapped with open-pit mining throughout. The open pit was phased out in the latter part of 1980.Underground production began in early 1979. The mining method employed in the first lift is sub-level blasthole open stoping with delayed hydraulic filling. Large-diameter (6.5-in.) holes are being drilled in the crop stope area and are also planned for some other areas for vertical retreat mining into a slot. GeologyThe orebody consists of numerous sulphide lenses of variable size, geometry and geology . The lenses occur within volcanoclastic host rocks which exhibit a strong variability in intensity and type of alteration and structural characteristics. Stope design and sequencing were based on these complex geological factors."

Jan 1, 1981

By S. A. Vazhnov, A. G. Kalimov, A. A. Potienko

In this paper we describe a mathematical model of the magnetic field and magnetohydrodynamic processes simulation in aluminum reduction cells developed in St. Petersburg State Polytechnic University, Russia. The model includes: (a) calculation of the currents in the busbar system and inside the aluminum cell construction elements including cathode and anode structures, aluminum and electrolyte layers; (b) magnetic field simulation using the integral equation method; ( c) investigation of the magnetohydrodynamic characteristics on the basis of a shallow-water approach. The developed model was used to investigate operational characteristics of the different industrial aluminum cells. Calculated magnetic field distributions and MHD stability parameters were compared with the available experimental information; the comparison demonstrated a reasonably good agreement.

Jan 1, 2006