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By Jack G. Hazan

The Critical Path Method is the modern scientific answer for solving the planning and scheduling problems inherent in today's complex projects. With this method, nothing is left to chance. All resources are controlled and kept to the minimum. The various phases are properly planned and strategically determined. Optimum conditions are evaluated for the most economical and fastest way to complete a definite project. The method must be fully understood and implemented with positive data and continuous feedback to obtain the best results. This paper covers the various aspects of the Critical Path Method and mentions some of its applications in the mining and metallurgical fields. T 0 progress to a higher state of human welfare necessarily involves sacrifices. The greatest sacrifice is to relinquish social freedom in favour of economic freedom. In the old days, for example, a cobbler was free to work at whatever time of the day he chose; today, he can't. He is now forced to adapt himself to environment and to work at stand-

Jan 1, 1965

By D. DeGagne, E. De Souza, J. F. Archibald

This paper describes the potential use of anew agent material for backfill consolidation, ground waste glass, to be used as partial replacement of Portland cement fractions within backfill. Significant fractions of commercial and residential silica glass production is currently utilized as waste landfill and must be disposed of at high cost and with no foreseeable environ-mental benefit. This paper also demonstrates that waste glass materials could be effectively recycled as backfill additives, and that a significant, large and stable source of additive supply, currently land filled, can be developed. This new application will generate added value for such materials, serve to promote positive environ-mental stewardship and satisfy engineering sup-port requirements in mines.

Jan 1, 1997

By D. G. Almond

Nkomati Nickel Mine in South Africa processes one of the world?s hardest ores in a 375k TPM autogenous grinding circuit. The plant employs an unconventional processing circuit, comprising a primary autogenous mill (AG or FAG) and pebble crushing circuit followed by a secondary hybrid pebble/ball mill and classification cyclone cluster. Advanced Process Control (APC) or Expert Control is now generally accepted as an advantage in most modern high capacity concentrator grinding circuits. This paper reviews the installation of model predictive control at Nkomati and examines the results and benefits of installation in an autogenous mill during plant ramp-up. The paper also demonstrates how predefining process control objectives together with good plant and supplier cooperation can achieve a robust and reliable APC implementation on a very short site program. The results conclusively demonstrate operational and economic benefits during circuit operation with the advanced process control system ON. Production performance and circuit stability were significantly better than during manual control.

Jan 1, 2012

By R. W. Lawrence

"The management of acid rock drainage( ARD) to prevent impact when tailings are disposed of in the environment requires understanding of the phenomena giving rise to acidic drainage, a rigorous evaluation of the weathering characteristics of the tailings, and the successful implementation of control measures that will be effective in the long term. This paper provides a brief theoretical background to the complex reactions taking place in mill tailings containing residual sulfide minerals which must be appreciated to enable waste characterization program to be effective in predicting the future behavior of the tailings and in designing control methods which will work. The principals and practice of prediction and control as part of an ARD management strategy will then be discussed.Paper Not Available at Time of Publication"

Jan 1, 1997

The Cadia mine is shifting from the open pit operation to the Cadia East underground block cave. The resulting increase in milled tonnes and the decrease in fines production through shifting to block caving require an increase of over 25% in installed power. This expansion is being accomplished via the installation of up-front crushing and HPGR milling of the ore, with the SAG mill receiving a secondary crushed feed. This design, criteria and rationale for selection is presented. Over the coming years, the mine will further expand capacity. The target is to accomplish this with minimal addition of installed power or use of fresh water. This presents a challenge that epitomizes the future constraints on our resource dependent and intensive industry. The approach and proposed options to this longer-term expansion are also presented.

Jan 1, 2012

By J. C. Marchand, M. A. Berube

"L'objectif principal recherché lors du broyage d 'un minerai est de libérer adéquatement ses valeurs utiles en vue de leur concentration ultérieure. La pratique courante consiste à tenter d'obtenir un produit de broyage d'une granulométrie constante. Malheureusement, les propriétés texturales des minéraux utiles varient naturellement dans un gisement et une telle stratégie n'entraine pas toujours pour ces minéraux un degré de libération constant. Pour un rendement optimal du procédé de concentration, cette variable très importante doit donc être périodiquement vérifiée.Jusqu'à maintenant, la plupart des études de libération des minerais se font en examinant des sections polies de particules du minerai broyé. Le GRAAIM a récemment assemblé un système modulaire d'analyse d'images qui servira en grande partie à des mesures automatiques du degré de libération des minéraux. Le système s'avère relativement peu coûteux comparativement à la plupart des analyseurs de texture conventionnels si l'on considère que plusieurs de ses composantes, par exemple le miniordinateur, sont utilisées à une foule d'autres applications, et il permet de plus une grande souplesse d'utilisation puisque l'on a qu'à construire des algorithmes de mesure et de calcul en fonction de l'objectif recherché. Des programmes particuliers permettant des études automatiques de libération sur des sections polies de particules ont ainsi été élaborés. Ils permettent également des mesures de teneurs et de distributions granulométriques apparentes des particules. Des résultats obtenus dans le cas de minerais de fer sont brièvement présentés afin d'illustrer la technique."

Jan 1, 1983

By C. W. Taylor, F. L. Martin

"THE DICTIONARY defines Metallurgy as the ""science or art of separating metals from their ores and refining them for use"". In these days, however, such a definition is not detailed enough.The modern science of metallurgy is based on two fundamental sciences, physics .and chemistry, and is sub-divided into two major fields: Process Metallurgy and Physical Metallurgy. These fields of metallurgy are now so comprehensive and involved that even the graduate metallurgist has to specialize in one or the other.In recent years, the relatively new science or technology of non• destructive testing has also entered the industrial scene, with tremendous impact and ramifications. So much so that, certainly, no .discussion on metallurgy can be complete without including some reference to it.Obviously, one paper cannot hope to cover in detail the relationship of the whole science of metallurgy to the mining industry. Consequently, only a very brief reference will be made to the field of Process Metallurgy, our major concern being with Physical Metallurgy and Non-Destructive Testing."

Jan 1, 1960

By Richard Stewart

There are highly competitive world markets in most of the minerals being mined today. The high standard of living we enjoy in North America results in ever increasing productivity through mechanization and automation. Conventional underground and open-pit mining practices throughout the world are constantly changing to reflect the engineering advances of our technology. New records in tunneling, shaft sinking and excavating are being established. Larger and faster equipment is in production. Mining operations are being studied in detail to improve materials, methods and machines. Standards and controls are being established to measure the performance of people and equipment. These steps all tend to improve our present performance. In addition to these short-range improvements, however, there are the basic research and applied research studies which are aimed at developing entirely new approaches to our mining problems. Basic research in rock mechanics is coupled with applied research in rock penetration, fragmentation and stabilization.

Jan 1, 1963

By L. R. Plitt

A series of experiments were carried out in an effort to develop a universally applicable mathematical model of the hydrocyclone classifier. The design and operating variables studied were: cyclone diameter and height, the inlet, vortex finder and apex diameters, the feed pressure and the solids content of the feed slurry. The model consists of four basic equations which express the cut size ( dso), volumetric split between overflow and underflow, volumetric throughput, and sharpness of separation in terms of the operating and design variables. Although empirical, the model is nevertheless in general agreement with fundamentally derived models. The model clearly 1•eveals the effect of the major variables on the operation of a hydrocyclone. Because of its broad data base and the inclusion of all the major variables, the model may be used without experimental data to predict the operation of cyclones over a wide range of different operating conditions. With operating data, the equations may be modified to serve as an operational model.

Jan 1, 1976

By V. Baboudjian, R. J. Geren, J. Thiriar

"The electrolytic tankhouse at CCR was recognized by management as lagging behind modem refineries in terms of productivity, energy efficiency and controls. The operation was also burdened by high maintenance costs of cells, floors and electrolyte recirculation systems.A bench marking program was started in 1986 to evaluate processes and other technology by visiting major copper refineries in North America, Europe and Japan. The basic principles necessary to optimize the operation were defined, and a program calledCCR 2000 was prepared for approval of the necessary capital investments.This paper describes the results obtained to date and outlines the remaining work to complete the modernization program, in particular, the control of electrolytes, the elimination of the Baltimore groove and studies to modernize the stripping operation or adopt permanent cathode technology.IntroductionThe CCR Refinery of Noranda Copper Smelting and Refining (Noranda Minerals Inc.) , in Montreal East, is one of the world 's largest custom copper and precious metal refineries with a capacity to refine 350000 tonnes of copper per year. The silver refinery, which treats the copper tankhouse anode slime, foreign slime and precious metal ingots, produces 800 000 kg of silver, 26 000 kg of gold and 3800 kg of platinum-palladium concentrate annually. Copper anodes are received from the Horne Smelter at Rouyn-Noranda, Quebec, and Mines Gaspe Division in Murdochville, Quebec. CCR also refines anodes from Hudson Bay Mining and Smelting Co. Ltd. in FIin Flon, Manitoba, and remelts anode scrap along with blister and purchased copper scrap ."

Jan 1, 1993

By C. M. Campbell

Canadian newspapers from coast to coast, have been, for months, denouncing those articles entitled, "The Whisper of Death," which have been appearing in the Montreal Star. I have not read these articles as the newspapers do not print them; they just denounce them or class them as jokes. Apparently they think that they are not suitable for the ordinary Canadian to read. It appears, however, that the Star has said that unless we balance our budget, and that soon, we shall be bankrupt. That seems to me like common sense, though the Victoria Times says editorially that the Star claims will "shortly find a place in the joke column". In this editorial the Times quotes with much enthusiasm from the Quebec Telegraph. "Canada," says the Telegraph, "is all right. Her natural resources are so vast that no one need worry. Her future possibilities are limitless; her assets beyond figures". Does it not seem like the limit of nonsense for a country that is not paying its running expenses to make such pretensions? After fifty-five years of Confederation and much talk of national status we are still sponging on the mother country for our external defense; we still allow the hard pressed tax-payer in the old land to shoulder the entire burden. We even now refuse to accept able-bodied working-men from that small and overcrowded country and yet blatently talk of limitless resources.

Jan 1, 1923

By R. J. Enright

Eight mines in canada and three in Australia were visited between September 1987 and Februacy 1988. All mines had encountered problems with sulphide dust explosions and had introduced defence mechanisms to prevent or limit the extent of these explosions. Techniques included dispersion of limestone by various methods, use of water foggers, placing of water and inert stenuning in blast holes, and removal of settled dust to prevent secondary explosions. The techniques were evaluated and it was concluded that certain practices should be modified or discontinued as they were of little value in preventing dust explosions.

May 11, 1988

By R. E. Eyre, L. P. Landucci

C URRENT practice in the zinc concentrate roasting plant of The Consolidated Mining arid Smelting Company of Canada Limited, at Trail, B.C., involves passing the furnace effluent gases through an electrostatic precipitator for the recovery of dust. After removal of the dust the gas is treated for recovery of sulphur dioxide by conversion into sulphuric acid ( 1). However. as roasting techniques improved, and furnace productivity in-creased, the rated capacity of the precipitator was exceeded and it was necessary to consider various means of improving the dust recovery. A study of methods indicated that a baghouse using silicone-treated glass fabric, might be suitable for this particular application. Glass fabric was chosen because the temperature of the roaster effluent gases would range from 450°F to 500°F and tempering air was undesirable to avoid dilution of the sulphur dioxide gas.

Jan 1, 1962

By George Delorme

"AbstractThe basic intention of this paper is to present, from a practical viewpoint, a thorough outline of all the sound and accepted principles connected with attaining satisfactory rope performance from multi-rope friction winders.In order to emphasize the importance of some aspects of rope maintenance, a limited amount of hoist rope theory has been included, a s it is felt that without this, some of the more critical, but nevertheless practical, aspects would perhaps pass without full appreciation of their individual merit.It is very much appreciated that many of the maintenance topics and practices discussed herein are already being observed with a high degree of skill among those already involved in modern friction winding. The hope is expressed, however, that the paper will be of additional assistance, and of particular help in introducing sound maintenance principles to those who are moving into this field of operation for the first time.Hoist RopesWITH a multi-rope friction winder system, structural upset within the hoist rope's cross section can occur if the ropes slip in the drum treads. This upset will usually appear at either end of the rope at the tangent point of the drum or deflection sheave with the respective conveyance in the normal uppermost position. This slipping action on the drum causes the outer cover of a Full Locked Coil or the strands of a stranded rope to shift, leading to structural upset. The result very often means that the ropes have to be withdrawn from service before completing their maximum service potential.The cause of any rope slipping in its tread can be associated with a discrepancy in tension of that rope between one side of the drum and the other."

Jan 1, 1977

By Kenneth L. Norris

Stonegate Agricom Ltd. is currently conducting exploration and development drilling of the Paris Hills Phosphate Project (Paris Hills Project) located in Bear Lake County, southeastern Idaho, 3.2 km west of the towns of Paris and Bloomington, Idaho. The project is located adjacent to a highway and 19 km by paved highway to Montpelier, Idaho where the Union Pacific Railroad system is located. Power and water are available locally. The nearest metropolitan centre is Salt Lake City, Utah approximately 225 km by road to the south-west of the property. The Paris Hills Project encompasses an area of approximately 856 hectares. Property holdings consist of three (3) patented lode mining claims and 16 contiguous fee parcels (some with federal phosphate leases). Active open pit phosphate mining operations are located in surrounding counties in south-east Idaho and are owned and operated by Agrium Inc., Monsanto Company and J.R. Simplot Company. The Paris Hills Project is located near the centre of the Western Phosphate Field which constitutes the most extensive phosphorite beds in the United States. Phosphate beds of the Western Phosphate Field occur within the Phosphoria Formation of Permian age and extend over an area of more than 350,000 km2 including extensive areas of Idaho, Utah, Wyoming and Montana. At Paris Hills the phosphate mineralized beds occur in the overturned limb and the horizontal limb of the Paris Syncline. Grades and thicknesses in both the western overturned limb and the eastern horizontal limb of the anticline are similar. The vast majority of potential mineralization occurs in the horizontal limb which underlies most of the property holdings. Mineralization in the overturned limb has a strike length of over three (3) kilometres and extends from the surface to a depth exceeding 300 m depending on location along the north-trending strike of outcrops. Depths of the horizontal limb range from surface along the north side of Bloomington Canyon to estimated depths of 915 to 1,035 m at Paris Canyon. The property contains an Inferred resource of 109.6 million tonnes at 23.6% P2O5 over two mineralized horizons. The phosphate zones have a strike length of over 3 km and extend from surface to a depth of at least 900 m. Drilling commenced late in the 3rd quarter of 2010 and is planned to continue through 2011. The drilling was planned to target an area of potentially higher grade phosphate mineralization and better define and upgrade the current resources.

May 1, 2011

By Dalton. J. L., H. P. Dibbs

An account is given of investigations into the application of two neutron methods to the on-line analysis of slurries. One deals with the application of the neutron moisture gauge principle to the determination of the water content of iron oxide slurries, and the other with the application of gamma radiation from thermal-neutron-capture to the determination of the composition of aqueous slurries of iron oxide, copper oxide, zinc oxide and sulphur. Linear relationships were found between the composition of the slurry and the neutron count-rate in the first study, and between the slurry composition and the prompt-gamma-ray count-rate in the second study. A mathematical relationship has also been developed which relates changes in the prompt-gamma-ray counts from hydrogen to changes in slurry composition.

Jan 1, 1973

By A. E. Hall

"This paper summarizes findings of a two-month investigation in Zambia and Zimbabwe and a one-month visit to Britain in1990-1991. United States contacts have supplied information about that country.Zambia's political unrest and severe devaluation, combined with developments in Namibia and South Africa, enhanced staff recruiting problems in the School of Mines. Zimbabwe has a strong and developing mining department. The departments of mining in the United States and Great Britain are readjusting and contracting due to the reduction in the scale of the industry.The above factors are reviewed and their impact on the countries evaluated.IntroductionCanada trains the majority of its mining engineers domestically but a significant number are recruited from other countries. Examination of the qualifications of 200 professional engineers registered in the mining discipline in British Columbia showed that125 received their first degree from a Canadian university, 33 graduated from institutions in the United States and 42 from the rest of the world including 30 from the United Kingdom. This is a rough and-ready sample but it indicates that developments in the education of mining engineers in the United States and in Britain are relevant to the Canadian mining industry.The recent changes in the world economy and political structure have significant implications for the mining industry and for the supply and training of engineers. Change in eastern Europe coupled with the downturn in mining, especially in the European coalfields, has enabled many engineers to travel freely to the West. The low gold price and the legislative changes in Africa that have improved access to education for Africans with the ability to fill responsible positions, have reduced the South African mining industry’s overseas recruitment to a minimal level. The Australian recession has also lowered their recruitment of mining engineers from other countries."

Jan 1, 1993

By C. Jay Hodgson, P. J. MacGeehan

"The gold ore zones of the Campbell and Dickenson mines occur within a km-wide, 2 km-long zone of highly altered and anomalously fissile and deformed volcanic and subvolcanic intrusive rocks, cut by a series of mainly post-deformation mafic and quartz-feldspar porphyry felsic dykes.Three main periods of gold ore-forming hydrothermal activity are recognized. In the first, the mine rocks were extensively altered and gold and arsenic enriched; syn-volcanic auriferous veinlet and low-grade chemical sedimentary ores were deposited in what was a major discharge zone of a submarine hydrothermal system. The chemical sedimentary ores are closely associated spatially and temporally with domal rhyolitic extrusions. Because of its mechanical and chemical properties, this synvolcanic alteration zone became the locus of later deformation, and the site of the generation of auriferous hydrothermal solutions, perhaps by pressure solution processes at depth. These solutions deposited, synchronously with deformation and metamorphism, the second and most economically important type of ore zones in the mine: large foliation-parallel and foliation-oblique banded carbonate- 'chert' Rssure-filling veins.In the third and final mineralizing event, high-grade, pipeshaped zones of siliceous replacement-type mineralization, and quartz-arsenopyrite-gold veins, were superimposed on the previous mineralization types after most of the deformation, but before the emplacement of the late dykes. The source of heat and also possibly the fluids for the third mineralizing period may have been the dyke-forming igneous activity. The textures and mineralogy of the banded carbonate- 'chert' veins suggest a near-surface (<3 km) environment of deposition, but their relationship to the fabric of their host rocks indicates they were emplaced in an environment, presumably at considerable depth (5-10 km?), in which the rocks were undergoing intense penetrative deformation. This anomaly is unresolved."

Jan 1, 1982

"8.1. IntroductionThe stoichiometry of most named platinum-group minerals (POM) is known (cf. Cabri, 1981b, in Chapter 7), but, because these minerals are subject to a wide range of element substitutions, representative analyses require treatment in a separate chapter (section 8.2). The analyses, in all cases done by electron microprobe, are grouped in sections according to the principal platinum-group element (POE) for each POM, and then follow sequentially with increasing amounts of the principal POE starting with the ideal composition, when known. In order to facilitate reference to specific POM by name, an alphabetical listing is also given (Table 8.1). A range of compositions, in addition to one or several ""representative"" analyses, is given for some POM when more than one analysis has been reported for a particular locality. The tables of POM analyses (Tables 8.2 to 8. 76) include at least one analysis for every locality for which data have been published, to the best of the authors' knowledge. All analyses are referenced for locality and publication source, and include several unpublished analyses (all but one done at CANMET). Most analyses have been rounded off to one decimal place for amounts more than one per cent and their formulae calculated on the basis of an even number of total atoms. In all tables, ''n.d.'' stands for elements sought for but not detected and a dash signifies elements not sought, or when these haven't been specificed in the publication source.Section 8.3 contains tabulated analyses and, in some cases, also includes a critical assessment of POE-bearing minerals in which the POE occur in trace or minor quantities. The organization of the data in this section is by mineral groups; e.g., sulphides, sulpharsenides, silicates, etc. Some of these data are also discussed in Chapter 4 by Crocket (1981) and are discussed briefly in Chapter 6 by Crocket and Cabri (1981)."

Jan 1, 1979

By R. F. Tylecote

"The closure of the iron and steel making plant at Consett in Durham in 1980 marked the end of an era-a long era in the world&apos;s iron and steel making history. Iron had been smelted in the Tyne-Wear area of the United Kingdom since before the Roman period, but apart from evidence of smithing in the Roman period, the historical evidence for iron production on a large scale dates from the 14th century.The paper describes sites in the area that first worked the bloomery process and then, in the 16th century, as did most of Europe, graduated to the blast furnace process. The main emphasis is on the early introduction of coal to iron making at the end of the 18th century and the use of the steam engine to render integrated sites possible.IntroductionIron has been smelted in the Tyne-Wear area of the United Kingdom since before the Roman period, but apart from clear evidence of smithing in the Roman period, the historical evidence for iron production on a large scale dates from the 14th century. Like many other countries, the United Kingdom benefitted from the visits of foreign observers, such as Jars, Svedenstierna, de la Houliere and Dufrenoy, who left detailed records. In modern times, information gained from excavations of iron and steel making sites has supplemented the historical record.Natural ResourcesUp to the end of the 19th century, the industry was wholly dependent on its own resources. Iron ore, limestone, wood, coal and water power were all found a short distance away from the main valleys of the Tyne and Wear. The main sources of iron ore were the coal measures, with rider ores from the lead vein s in Alston and Weardale, and carbonate ores from shale horizons in the Carboniferous limestone. Good coking coal was available from West Durham and reasonable coal from the Tyne valley and Northumberland limestone. Limestone was plentiful."

Jan 1, 1983